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hmm related patches for 5.5 

This is another round of bug fixing and cleanup. This time the focus is on
 the driver pattern to use mmu notifiers to monitor a VA range. This code
 is lifted out of many drivers and hmm_mirror directly into the
 mmu_notifier core and written using the best ideas from all the driver
 implementations.
 
 This removes many bugs from the drivers and has a very pleasing
 diffstat. More drivers can still be converted, but that is for another
 cycle.
 
 - A shared branch with RDMA reworking the RDMA ODP implementation
 
 - New mmu_interval_notifier API. This is focused on the use case of
   monitoring a VA and simplifies the process for drivers
 
 - A common seq-count locking scheme built into the mmu_interval_notifier
   API usable by drivers that call get_user_pages() or hmm_range_fault()
   with the VA range
 
 - Conversion of mlx5 ODP, hfi1, radeon, nouveau, AMD GPU, and Xen GntDev
   drivers to the new API. This deletes a lot of wonky driver code.
 
 - Two improvements for hmm_range_fault(), from testing done by Ralph
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Pull hmm updates from Jason Gunthorpe:
 "This is another round of bug fixing and cleanup. This time the focus
  is on the driver pattern to use mmu notifiers to monitor a VA range.
  This code is lifted out of many drivers and hmm_mirror directly into
  the mmu_notifier core and written using the best ideas from all the
  driver implementations.

  This removes many bugs from the drivers and has a very pleasing
  diffstat. More drivers can still be converted, but that is for another
  cycle.

   - A shared branch with RDMA reworking the RDMA ODP implementation

   - New mmu_interval_notifier API. This is focused on the use case of
     monitoring a VA and simplifies the process for drivers

   - A common seq-count locking scheme built into the
     mmu_interval_notifier API usable by drivers that call
     get_user_pages() or hmm_range_fault() with the VA range

   - Conversion of mlx5 ODP, hfi1, radeon, nouveau, AMD GPU, and Xen
     GntDev drivers to the new API. This deletes a lot of wonky driver
     code.

   - Two improvements for hmm_range_fault(), from testing done by Ralph"

* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  mm/hmm: remove hmm_range_dma_map and hmm_range_dma_unmap
  mm/hmm: make full use of walk_page_range()
  xen/gntdev: use mmu_interval_notifier_insert
  mm/hmm: remove hmm_mirror and related
  drm/amdgpu: Use mmu_interval_notifier instead of hmm_mirror
  drm/amdgpu: Use mmu_interval_insert instead of hmm_mirror
  drm/amdgpu: Call find_vma under mmap_sem
  nouveau: use mmu_interval_notifier instead of hmm_mirror
  nouveau: use mmu_notifier directly for invalidate_range_start
  drm/radeon: use mmu_interval_notifier_insert
  RDMA/hfi1: Use mmu_interval_notifier_insert for user_exp_rcv
  RDMA/odp: Use mmu_interval_notifier_insert()
  mm/hmm: define the pre-processor related parts of hmm.h even if disabled
  mm/hmm: allow hmm_range to be used with a mmu_interval_notifier or hmm_mirror
  mm/mmu_notifier: add an interval tree notifier
  mm/mmu_notifier: define the header pre-processor parts even if disabled
  mm/hmm: allow snapshot of the special zero page
This commit is contained in:
Linus Torvalds 2019-11-30 10:33:14 -08:00
parent d5bb349dbb 93f4e735b6
commit aa32f11691
31 changed files with 1303 additions and 2144 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

99
Documentation/vm/hmm.rst
View File

@ -147,49 +147,16 @@ Address space mirroring implementation and API
Address space mirroring's main objective is to allow duplication of a range of Address space mirroring's main objective is to allow duplication of a range of
CPU page table into a device page table; HMM helps keep both synchronized. A CPU page table into a device page table; HMM helps keep both synchronized. A
device driver that wants to mirror a process address space must start with the device driver that wants to mirror a process address space must start with the
registration of an hmm_mirror struct:: registration of a mmu_interval_notifier::
int hmm_mirror_register(struct hmm_mirror *mirror, mni->ops = &driver_ops;
int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
unsigned long start, unsigned long length,
struct mm_struct *mm); struct mm_struct *mm);
The mirror struct has a set of callbacks that are used During the driver_ops->invalidate() callback the device driver must perform
to propagate CPU page tables:: the update action to the range (mark range read only, or fully unmap,
etc.). The device must complete the update before the driver callback returns.
struct hmm_mirror_ops {
/* release() - release hmm_mirror
*
* @mirror: pointer to struct hmm_mirror
*
* This is called when the mm_struct is being released. The callback
* must ensure that all access to any pages obtained from this mirror
* is halted before the callback returns. All future access should
* fault.
*/
void (*release)(struct hmm_mirror *mirror);
/* sync_cpu_device_pagetables() - synchronize page tables
*
* @mirror: pointer to struct hmm_mirror
* @update: update information (see struct mmu_notifier_range)
* Return: -EAGAIN if update.blockable false and callback need to
* block, 0 otherwise.
*
* This callback ultimately originates from mmu_notifiers when the CPU
* page table is updated. The device driver must update its page table
* in response to this callback. The update argument tells what action
* to perform.
*
* The device driver must not return from this callback until the device
* page tables are completely updated (TLBs flushed, etc); this is a
* synchronous call.
*/
int (*sync_cpu_device_pagetables)(struct hmm_mirror *mirror,
const struct hmm_update *update);
};
The device driver must perform the update action to the range (mark range
read only, or fully unmap, etc.). The device must complete the update before
the driver callback returns.
When the device driver wants to populate a range of virtual addresses, it can When the device driver wants to populate a range of virtual addresses, it can
use:: use::
@ -216,70 +183,46 @@ The usage pattern is::
struct hmm_range range; struct hmm_range range;
... ...
range.notifier = &mni;
range.start = ...; range.start = ...;
range.end = ...; range.end = ...;
range.pfns = ...; range.pfns = ...;
range.flags = ...; range.flags = ...;
range.values = ...; range.values = ...;
range.pfn_shift = ...; range.pfn_shift = ...;
hmm_range_register(&range, mirror);
/* if (!mmget_not_zero(mni->notifier.mm))
* Just wait for range to be valid, safe to ignore return value as we return -EFAULT;
* will use the return value of hmm_range_fault() below under the
* mmap_sem to ascertain the validity of the range.
*/
hmm_range_wait_until_valid(&range, TIMEOUT_IN_MSEC);
again: again:
range.notifier_seq = mmu_interval_read_begin(&mni);
down_read(&mm->mmap_sem); down_read(&mm->mmap_sem);
ret = hmm_range_fault(&range, HMM_RANGE_SNAPSHOT); ret = hmm_range_fault(&range, HMM_RANGE_SNAPSHOT);
if (ret) { if (ret) {
up_read(&mm->mmap_sem); up_read(&mm->mmap_sem);
if (ret == -EBUSY) { if (ret == -EBUSY)
/*
* No need to check hmm_range_wait_until_valid() return value
* on retry we will get proper error with hmm_range_fault()
*/
hmm_range_wait_until_valid(&range, TIMEOUT_IN_MSEC);
goto again; goto again;
}
hmm_range_unregister(&range);
return ret; return ret;
} }
take_lock(driver->update);
if (!hmm_range_valid(&range)) {
release_lock(driver->update);
up_read(&mm->mmap_sem); up_read(&mm->mmap_sem);
take_lock(driver->update);
if (mmu_interval_read_retry(&ni, range.notifier_seq) {
release_lock(driver->update);
goto again; goto again;
} }
// Use pfns array content to update device page table /* Use pfns array content to update device page table,
* under the update lock */
hmm_range_unregister(&range);
release_lock(driver->update); release_lock(driver->update);
up_read(&mm->mmap_sem);
return 0; return 0;
} }
The driver->update lock is the same lock that the driver takes inside its The driver->update lock is the same lock that the driver takes inside its
sync_cpu_device_pagetables() callback. That lock must be held before calling invalidate() callback. That lock must be held before calling
hmm_range_valid() to avoid any race with a concurrent CPU page table update. mmu_interval_read_retry() to avoid any race with a concurrent CPU page table
update.
HMM implements all this on top of the mmu_notifier API because we wanted a
simpler API and also to be able to perform optimizations latter on like doing
concurrent device updates in multi-devices scenario.
HMM also serves as an impedance mismatch between how CPU page table updates
are done (by CPU write to the page table and TLB flushes) and how devices
update their own page table. Device updates are a multi-step process. First,
appropriate commands are written to a buffer, then this buffer is scheduled for
execution on the device. It is only once the device has executed commands in
the buffer that the update is done. Creating and scheduling the update command
buffer can happen concurrently for multiple devices. Waiting for each device to
report commands as executed is serialized (there is no point in doing this
concurrently).
Leverage default_flags and pfn_flags_mask Leverage default_flags and pfn_flags_mask
========================================= =========================================

2
drivers/gpu/drm/amd/amdgpu/amdgpu.h
View File

@ -967,6 +967,8 @@ struct amdgpu_device {
struct mutex lock_reset; struct mutex lock_reset;
struct amdgpu_doorbell_index doorbell_index; struct amdgpu_doorbell_index doorbell_index;
struct mutex notifier_lock;
int asic_reset_res; int asic_reset_res;
struct work_struct xgmi_reset_work; struct work_struct xgmi_reset_work;

9
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
View File

@ -505,8 +505,7 @@ static void remove_kgd_mem_from_kfd_bo_list(struct kgd_mem *mem,
* *
* Returns 0 for success, negative errno for errors. * Returns 0 for success, negative errno for errors.
*/ */
static int init_user_pages(struct kgd_mem *mem, struct mm_struct *mm, static int init_user_pages(struct kgd_mem *mem, uint64_t user_addr)
uint64_t user_addr)
{ {
struct amdkfd_process_info *process_info = mem->process_info; struct amdkfd_process_info *process_info = mem->process_info;
struct amdgpu_bo *bo = mem->bo; struct amdgpu_bo *bo = mem->bo;
@ -1199,7 +1198,7 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
add_kgd_mem_to_kfd_bo_list(*mem, avm->process_info, user_addr); add_kgd_mem_to_kfd_bo_list(*mem, avm->process_info, user_addr);
if (user_addr) { if (user_addr) {
ret = init_user_pages(*mem, current->mm, user_addr); ret = init_user_pages(*mem, user_addr);
if (ret) if (ret)
goto allocate_init_user_pages_failed; goto allocate_init_user_pages_failed;
} }
@ -1744,6 +1743,10 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info,
return ret; return ret;
} }
/*
* FIXME: Cannot ignore the return code, must hold
* notifier_lock
*/
amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm); amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
/* Mark the BO as valid unless it was invalidated /* Mark the BO as valid unless it was invalidated

14
drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
View File

@ -538,8 +538,6 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
e->tv.num_shared = 2; e->tv.num_shared = 2;
amdgpu_bo_list_get_list(p->bo_list, &p->validated); amdgpu_bo_list_get_list(p->bo_list, &p->validated);
if (p->bo_list->first_userptr != p->bo_list->num_entries)
p->mn = amdgpu_mn_get(p->adev, AMDGPU_MN_TYPE_GFX);
INIT_LIST_HEAD(&duplicates); INIT_LIST_HEAD(&duplicates);
amdgpu_vm_get_pd_bo(&fpriv->vm, &p->validated, &p->vm_pd); amdgpu_vm_get_pd_bo(&fpriv->vm, &p->validated, &p->vm_pd);
@ -1219,11 +1217,11 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
if (r) if (r)
goto error_unlock; goto error_unlock;
/* No memory allocation is allowed while holding the mn lock. /* No memory allocation is allowed while holding the notifier lock.
* p->mn is hold until amdgpu_cs_submit is finished and fence is added * The lock is held until amdgpu_cs_submit is finished and fence is
* to BOs. * added to BOs.
*/ */
amdgpu_mn_lock(p->mn); mutex_lock(&p->adev->notifier_lock);
/* If userptr are invalidated after amdgpu_cs_parser_bos(), return /* If userptr are invalidated after amdgpu_cs_parser_bos(), return
* -EAGAIN, drmIoctl in libdrm will restart the amdgpu_cs_ioctl. * -EAGAIN, drmIoctl in libdrm will restart the amdgpu_cs_ioctl.
@ -1266,13 +1264,13 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
amdgpu_vm_move_to_lru_tail(p->adev, &fpriv->vm); amdgpu_vm_move_to_lru_tail(p->adev, &fpriv->vm);
ttm_eu_fence_buffer_objects(&p->ticket, &p->validated, p->fence); ttm_eu_fence_buffer_objects(&p->ticket, &p->validated, p->fence);
amdgpu_mn_unlock(p->mn); mutex_unlock(&p->adev->notifier_lock);
return 0; return 0;
error_abort: error_abort:
drm_sched_job_cleanup(&job->base); drm_sched_job_cleanup(&job->base);
amdgpu_mn_unlock(p->mn); mutex_unlock(&p->adev->notifier_lock);
error_unlock: error_unlock:
amdgpu_job_free(job); amdgpu_job_free(job);

1
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
View File

@ -2794,6 +2794,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
mutex_init(&adev->virt.vf_errors.lock); mutex_init(&adev->virt.vf_errors.lock);
hash_init(adev->mn_hash); hash_init(adev->mn_hash);
mutex_init(&adev->lock_reset); mutex_init(&adev->lock_reset);
mutex_init(&adev->notifier_lock);
mutex_init(&adev->virt.dpm_mutex); mutex_init(&adev->virt.dpm_mutex);
mutex_init(&adev->psp.mutex); mutex_init(&adev->psp.mutex);

442
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
View File

@ -51,439 +51,107 @@
#include "amdgpu_amdkfd.h" #include "amdgpu_amdkfd.h"
/** /**
* struct amdgpu_mn_node * amdgpu_mn_invalidate_gfx - callback to notify about mm change
* *
* @it: interval node defining start-last of the affected address range * @mni: the range (mm) is about to update
* @bos: list of all BOs in the affected address range * @range: details on the invalidation
* * @cur_seq: Value to pass to mmu_interval_set_seq()
* Manages all BOs which are affected of a certain range of address space.
*/
struct amdgpu_mn_node {
struct interval_tree_node it;
struct list_head bos;
};
/**
* amdgpu_mn_destroy - destroy the HMM mirror
*
* @work: previously sheduled work item
*
* Lazy destroys the notifier from a work item
*/
static void amdgpu_mn_destroy(struct work_struct *work)
{
struct amdgpu_mn *amn = container_of(work, struct amdgpu_mn, work);
struct amdgpu_device *adev = amn->adev;
struct amdgpu_mn_node *node, *next_node;
struct amdgpu_bo *bo, *next_bo;
mutex_lock(&adev->mn_lock);
down_write(&amn->lock);
hash_del(&amn->node);
rbtree_postorder_for_each_entry_safe(node, next_node,
&amn->objects.rb_root, it.rb) {
list_for_each_entry_safe(bo, next_bo, &node->bos, mn_list) {
bo->mn = NULL;
list_del_init(&bo->mn_list);
}
kfree(node);
}
up_write(&amn->lock);
mutex_unlock(&adev->mn_lock);
hmm_mirror_unregister(&amn->mirror);
kfree(amn);
}
/**
* amdgpu_hmm_mirror_release - callback to notify about mm destruction
*
* @mirror: the HMM mirror (mm) this callback is about
*
* Shedule a work item to lazy destroy HMM mirror.
*/
static void amdgpu_hmm_mirror_release(struct hmm_mirror *mirror)
{
struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
INIT_WORK(&amn->work, amdgpu_mn_destroy);
schedule_work(&amn->work);
}
/**
* amdgpu_mn_lock - take the write side lock for this notifier
*
* @mn: our notifier
*/
void amdgpu_mn_lock(struct amdgpu_mn *mn)
{
if (mn)
down_write(&mn->lock);
}
/**
* amdgpu_mn_unlock - drop the write side lock for this notifier
*
* @mn: our notifier
*/
void amdgpu_mn_unlock(struct amdgpu_mn *mn)
{
if (mn)
up_write(&mn->lock);
}
/**
* amdgpu_mn_read_lock - take the read side lock for this notifier
*
* @amn: our notifier
* @blockable: is the notifier blockable
*/
static int amdgpu_mn_read_lock(struct amdgpu_mn *amn, bool blockable)
{
if (blockable)
down_read(&amn->lock);
else if (!down_read_trylock(&amn->lock))
return -EAGAIN;
return 0;
}
/**
* amdgpu_mn_read_unlock - drop the read side lock for this notifier
*
* @amn: our notifier
*/
static void amdgpu_mn_read_unlock(struct amdgpu_mn *amn)
{
up_read(&amn->lock);
}
/**
* amdgpu_mn_invalidate_node - unmap all BOs of a node
*
* @node: the node with the BOs to unmap
* @start: start of address range affected
* @end: end of address range affected
* *
* Block for operations on BOs to finish and mark pages as accessed and * Block for operations on BOs to finish and mark pages as accessed and
* potentially dirty. * potentially dirty.
*/ */
static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node, static bool amdgpu_mn_invalidate_gfx(struct mmu_interval_notifier *mni,
unsigned long start, const struct mmu_notifier_range *range,
unsigned long end) unsigned long cur_seq)
{ {
struct amdgpu_bo *bo; struct amdgpu_bo *bo = container_of(mni, struct amdgpu_bo, notifier);
struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
long r; long r;
list_for_each_entry(bo, &node->bos, mn_list) { if (!mmu_notifier_range_blockable(range))
return false;
if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, start, end)) mutex_lock(&adev->notifier_lock);
continue;
r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, mmu_interval_set_seq(mni, cur_seq);
true, false, MAX_SCHEDULE_TIMEOUT);
r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, true, false,
MAX_SCHEDULE_TIMEOUT);
mutex_unlock(&adev->notifier_lock);
if (r <= 0) if (r <= 0)
DRM_ERROR("(%ld) failed to wait for user bo\n", r); DRM_ERROR("(%ld) failed to wait for user bo\n", r);
} return true;
} }
/** static const struct mmu_interval_notifier_ops amdgpu_mn_gfx_ops = {
* amdgpu_mn_sync_pagetables_gfx - callback to notify about mm change .invalidate = amdgpu_mn_invalidate_gfx,
*
* @mirror: the hmm_mirror (mm) is about to update
* @update: the update start, end address
*
* Block for operations on BOs to finish and mark pages as accessed and
* potentially dirty.
*/
static int
amdgpu_mn_sync_pagetables_gfx(struct hmm_mirror *mirror,
const struct mmu_notifier_range *update)
{
struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
unsigned long start = update->start;
unsigned long end = update->end;
bool blockable = mmu_notifier_range_blockable(update);
struct interval_tree_node *it;
/* notification is exclusive, but interval is inclusive */
end -= 1;
/* TODO we should be able to split locking for interval tree and
* amdgpu_mn_invalidate_node
*/
if (amdgpu_mn_read_lock(amn, blockable))
return -EAGAIN;
it = interval_tree_iter_first(&amn->objects, start, end);
while (it) {
struct amdgpu_mn_node *node;
if (!blockable) {
amdgpu_mn_read_unlock(amn);
return -EAGAIN;
}
node = container_of(it, struct amdgpu_mn_node, it);
it = interval_tree_iter_next(it, start, end);
amdgpu_mn_invalidate_node(node, start, end);
}
amdgpu_mn_read_unlock(amn);
return 0;
}
/**
* amdgpu_mn_sync_pagetables_hsa - callback to notify about mm change
*
* @mirror: the hmm_mirror (mm) is about to update
* @update: the update start, end address
*
* We temporarily evict all BOs between start and end. This
* necessitates evicting all user-mode queues of the process. The BOs
* are restorted in amdgpu_mn_invalidate_range_end_hsa.
*/
static int
amdgpu_mn_sync_pagetables_hsa(struct hmm_mirror *mirror,
const struct mmu_notifier_range *update)
{
struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
unsigned long start = update->start;
unsigned long end = update->end;
bool blockable = mmu_notifier_range_blockable(update);
struct interval_tree_node *it;
/* notification is exclusive, but interval is inclusive */
end -= 1;
if (amdgpu_mn_read_lock(amn, blockable))
return -EAGAIN;
it = interval_tree_iter_first(&amn->objects, start, end);
while (it) {
struct amdgpu_mn_node *node;
struct amdgpu_bo *bo;
if (!blockable) {
amdgpu_mn_read_unlock(amn);
return -EAGAIN;
}
node = container_of(it, struct amdgpu_mn_node, it);
it = interval_tree_iter_next(it, start, end);
list_for_each_entry(bo, &node->bos, mn_list) {
struct kgd_mem *mem = bo->kfd_bo;
if (amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm,
start, end))
amdgpu_amdkfd_evict_userptr(mem, amn->mm);
}
}
amdgpu_mn_read_unlock(amn);
return 0;
}
/* Low bits of any reasonable mm pointer will be unused due to struct
* alignment. Use these bits to make a unique key from the mm pointer
* and notifier type.
*/
#define AMDGPU_MN_KEY(mm, type) ((unsigned long)(mm) + (type))
static struct hmm_mirror_ops amdgpu_hmm_mirror_ops[] = {
[AMDGPU_MN_TYPE_GFX] = {
.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables_gfx,
.release = amdgpu_hmm_mirror_release
},
[AMDGPU_MN_TYPE_HSA] = {
.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables_hsa,
.release = amdgpu_hmm_mirror_release
},
}; };
/** /**
* amdgpu_mn_get - create HMM mirror context * amdgpu_mn_invalidate_hsa - callback to notify about mm change
* *
* @adev: amdgpu device pointer * @mni: the range (mm) is about to update
* @type: type of MMU notifier context * @range: details on the invalidation
* @cur_seq: Value to pass to mmu_interval_set_seq()
* *
* Creates a HMM mirror context for current->mm. * We temporarily evict the BO attached to this range. This necessitates
* evicting all user-mode queues of the process.
*/ */
struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev, static bool amdgpu_mn_invalidate_hsa(struct mmu_interval_notifier *mni,
enum amdgpu_mn_type type) const struct mmu_notifier_range *range,
unsigned long cur_seq)
{ {
struct mm_struct *mm = current->mm; struct amdgpu_bo *bo = container_of(mni, struct amdgpu_bo, notifier);
struct amdgpu_mn *amn; struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
unsigned long key = AMDGPU_MN_KEY(mm, type);
int r;
mutex_lock(&adev->mn_lock); if (!mmu_notifier_range_blockable(range))
if (down_write_killable(&mm->mmap_sem)) { return false;
mutex_unlock(&adev->mn_lock);
return ERR_PTR(-EINTR);
}
hash_for_each_possible(adev->mn_hash, amn, node, key) mutex_lock(&adev->notifier_lock);
if (AMDGPU_MN_KEY(amn->mm, amn->type) == key)
goto release_locks;
amn = kzalloc(sizeof(*amn), GFP_KERNEL); mmu_interval_set_seq(mni, cur_seq);
if (!amn) {
amn = ERR_PTR(-ENOMEM);
goto release_locks;
}
amn->adev = adev; amdgpu_amdkfd_evict_userptr(bo->kfd_bo, bo->notifier.mm);
amn->mm = mm; mutex_unlock(&adev->notifier_lock);
init_rwsem(&amn->lock);
amn->type = type;
amn->objects = RB_ROOT_CACHED;
amn->mirror.ops = &amdgpu_hmm_mirror_ops[type]; return true;
r = hmm_mirror_register(&amn->mirror, mm);
if (r)
goto free_amn;
hash_add(adev->mn_hash, &amn->node, AMDGPU_MN_KEY(mm, type));
release_locks:
up_write(&mm->mmap_sem);
mutex_unlock(&adev->mn_lock);
return amn;
free_amn:
up_write(&mm->mmap_sem);
mutex_unlock(&adev->mn_lock);
kfree(amn);
return ERR_PTR(r);
} }
static const struct mmu_interval_notifier_ops amdgpu_mn_hsa_ops = {
.invalidate = amdgpu_mn_invalidate_hsa,
};
/** /**
* amdgpu_mn_register - register a BO for notifier updates * amdgpu_mn_register - register a BO for notifier updates
* *
* @bo: amdgpu buffer object * @bo: amdgpu buffer object
* @addr: userptr addr we should monitor * @addr: userptr addr we should monitor
* *
* Registers an HMM mirror for the given BO at the specified address. * Registers a mmu_notifier for the given BO at the specified address.
* Returns 0 on success, -ERRNO if anything goes wrong. * Returns 0 on success, -ERRNO if anything goes wrong.
*/ */
int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr) int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
{ {
unsigned long end = addr + amdgpu_bo_size(bo) - 1; if (bo->kfd_bo)
struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev); return mmu_interval_notifier_insert(&bo->notifier, current->mm,
enum amdgpu_mn_type type = addr, amdgpu_bo_size(bo),
bo->kfd_bo ? AMDGPU_MN_TYPE_HSA : AMDGPU_MN_TYPE_GFX; &amdgpu_mn_hsa_ops);
struct amdgpu_mn *amn; return mmu_interval_notifier_insert(&bo->notifier, current->mm, addr,
struct amdgpu_mn_node *node = NULL, *new_node; amdgpu_bo_size(bo),
struct list_head bos; &amdgpu_mn_gfx_ops);
struct interval_tree_node *it;
amn = amdgpu_mn_get(adev, type);
if (IS_ERR(amn))
return PTR_ERR(amn);
new_node = kmalloc(sizeof(*new_node), GFP_KERNEL);
if (!new_node)
return -ENOMEM;
INIT_LIST_HEAD(&bos);
down_write(&amn->lock);
while ((it = interval_tree_iter_first(&amn->objects, addr, end))) {
kfree(node);
node = container_of(it, struct amdgpu_mn_node, it);
interval_tree_remove(&node->it, &amn->objects);
addr = min(it->start, addr);
end = max(it->last, end);
list_splice(&node->bos, &bos);
}
if (!node)
node = new_node;
else
kfree(new_node);
bo->mn = amn;
node->it.start = addr;
node->it.last = end;
INIT_LIST_HEAD(&node->bos);
list_splice(&bos, &node->bos);
list_add(&bo->mn_list, &node->bos);
interval_tree_insert(&node->it, &amn->objects);
up_write(&amn->lock);
return 0;
} }
/** /**
* amdgpu_mn_unregister - unregister a BO for HMM mirror updates * amdgpu_mn_unregister - unregister a BO for notifier updates
* *
* @bo: amdgpu buffer object * @bo: amdgpu buffer object
* *
* Remove any registration of HMM mirror updates from the buffer object. * Remove any registration of mmu notifier updates from the buffer object.
*/ */
void amdgpu_mn_unregister(struct amdgpu_bo *bo) void amdgpu_mn_unregister(struct amdgpu_bo *bo)
{ {
struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev); if (!bo->notifier.mm)
struct amdgpu_mn *amn;
struct list_head *head;
mutex_lock(&adev->mn_lock);
amn = bo->mn;
if (amn == NULL) {
mutex_unlock(&adev->mn_lock);
return; return;
} mmu_interval_notifier_remove(&bo->notifier);
bo->notifier.mm = NULL;
down_write(&amn->lock);
/* save the next list entry for later */
head = bo->mn_list.next;
bo->mn = NULL;
list_del_init(&bo->mn_list);
if (list_empty(head)) {
struct amdgpu_mn_node *node;
node = container_of(head, struct amdgpu_mn_node, bos);
interval_tree_remove(&node->it, &amn->objects);
kfree(node);
}
up_write(&amn->lock);
mutex_unlock(&adev->mn_lock);
}
/* flags used by HMM internal, not related to CPU/GPU PTE flags */
static const uint64_t hmm_range_flags[HMM_PFN_FLAG_MAX] = {
(1 << 0), /* HMM_PFN_VALID */
(1 << 1), /* HMM_PFN_WRITE */
0 /* HMM_PFN_DEVICE_PRIVATE */
};
static const uint64_t hmm_range_values[HMM_PFN_VALUE_MAX] = {
0xfffffffffffffffeUL, /* HMM_PFN_ERROR */
0, /* HMM_PFN_NONE */
0xfffffffffffffffcUL /* HMM_PFN_SPECIAL */
};
void amdgpu_hmm_init_range(struct hmm_range *range)
{
if (range) {
range->flags = hmm_range_flags;
range->values = hmm_range_values;
range->pfn_shift = PAGE_SHIFT;
}
} }

53
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
View File

@ -30,63 +30,10 @@
#include <linux/workqueue.h> #include <linux/workqueue.h>
#include <linux/interval_tree.h> #include <linux/interval_tree.h>
enum amdgpu_mn_type {
AMDGPU_MN_TYPE_GFX,
AMDGPU_MN_TYPE_HSA,
};
/**
* struct amdgpu_mn
*
* @adev: amdgpu device pointer
* @mm: process address space
* @type: type of MMU notifier
* @work: destruction work item
* @node: hash table node to find structure by adev and mn
* @lock: rw semaphore protecting the notifier nodes
* @objects: interval tree containing amdgpu_mn_nodes
* @mirror: HMM mirror function support
*
* Data for each amdgpu device and process address space.
*/
struct amdgpu_mn {
/* constant after initialisation */
struct amdgpu_device *adev;
struct mm_struct *mm;
enum amdgpu_mn_type type;
/* only used on destruction */
struct work_struct work;
/* protected by adev->mn_lock */
struct hlist_node node;
/* objects protected by lock */
struct rw_semaphore lock;
struct rb_root_cached objects;
#ifdef CONFIG_HMM_MIRROR
/* HMM mirror */
struct hmm_mirror mirror;
#endif
};
#if defined(CONFIG_HMM_MIRROR) #if defined(CONFIG_HMM_MIRROR)
void amdgpu_mn_lock(struct amdgpu_mn *mn);
void amdgpu_mn_unlock(struct amdgpu_mn *mn);
struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
enum amdgpu_mn_type type);
int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr); int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr);
void amdgpu_mn_unregister(struct amdgpu_bo *bo); void amdgpu_mn_unregister(struct amdgpu_bo *bo);
void amdgpu_hmm_init_range(struct hmm_range *range);
#else #else
static inline void amdgpu_mn_lock(struct amdgpu_mn *mn) {}
static inline void amdgpu_mn_unlock(struct amdgpu_mn *mn) {}
static inline struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
enum amdgpu_mn_type type)
{
return NULL;
}
static inline int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr) static inline int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
{ {
DRM_WARN_ONCE("HMM_MIRROR kernel config option is not enabled, " DRM_WARN_ONCE("HMM_MIRROR kernel config option is not enabled, "

11
drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
View File

@ -30,6 +30,9 @@
#include <drm/amdgpu_drm.h> #include <drm/amdgpu_drm.h>
#include "amdgpu.h" #include "amdgpu.h"
#ifdef CONFIG_MMU_NOTIFIER
#include <linux/mmu_notifier.h>
#endif
#define AMDGPU_BO_INVALID_OFFSET LONG_MAX #define AMDGPU_BO_INVALID_OFFSET LONG_MAX
#define AMDGPU_BO_MAX_PLACEMENTS 3 #define AMDGPU_BO_MAX_PLACEMENTS 3
@ -101,10 +104,12 @@ struct amdgpu_bo {
struct ttm_bo_kmap_obj dma_buf_vmap; struct ttm_bo_kmap_obj dma_buf_vmap;
struct amdgpu_mn *mn; struct amdgpu_mn *mn;
union {
struct list_head mn_list; #ifdef CONFIG_MMU_NOTIFIER
struct mmu_interval_notifier notifier;
#endif
struct list_head shadow_list; struct list_head shadow_list;
};
struct kgd_mem *kfd_bo; struct kgd_mem *kfd_bo;
}; };

147
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
View File

@ -35,6 +35,7 @@
#include <linux/hmm.h> #include <linux/hmm.h>
#include <linux/pagemap.h> #include <linux/pagemap.h>
#include <linux/sched/task.h> #include <linux/sched/task.h>
#include <linux/sched/mm.h>
#include <linux/seq_file.h> #include <linux/seq_file.h>
#include <linux/slab.h> #include <linux/slab.h>
#include <linux/swap.h> #include <linux/swap.h>
@ -769,6 +770,20 @@ struct amdgpu_ttm_tt {
#endif #endif
}; };
#ifdef CONFIG_DRM_AMDGPU_USERPTR
/* flags used by HMM internal, not related to CPU/GPU PTE flags */
static const uint64_t hmm_range_flags[HMM_PFN_FLAG_MAX] = {
(1 << 0), /* HMM_PFN_VALID */
(1 << 1), /* HMM_PFN_WRITE */
0 /* HMM_PFN_DEVICE_PRIVATE */
};
static const uint64_t hmm_range_values[HMM_PFN_VALUE_MAX] = {
0xfffffffffffffffeUL, /* HMM_PFN_ERROR */
0, /* HMM_PFN_NONE */
0xfffffffffffffffcUL /* HMM_PFN_SPECIAL */
};
/** /**
* amdgpu_ttm_tt_get_user_pages - get device accessible pages that back user * amdgpu_ttm_tt_get_user_pages - get device accessible pages that back user
* memory and start HMM tracking CPU page table update * memory and start HMM tracking CPU page table update
@ -776,85 +791,89 @@ struct amdgpu_ttm_tt {
* Calling function must call amdgpu_ttm_tt_userptr_range_done() once and only * Calling function must call amdgpu_ttm_tt_userptr_range_done() once and only
* once afterwards to stop HMM tracking * once afterwards to stop HMM tracking
*/ */
#if IS_ENABLED(CONFIG_DRM_AMDGPU_USERPTR)
#define MAX_RETRY_HMM_RANGE_FAULT 16
int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo, struct page **pages) int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo, struct page **pages)
{ {
struct hmm_mirror *mirror = bo->mn ? &bo->mn->mirror : NULL;
struct ttm_tt *ttm = bo->tbo.ttm; struct ttm_tt *ttm = bo->tbo.ttm;
struct amdgpu_ttm_tt *gtt = (void *)ttm; struct amdgpu_ttm_tt *gtt = (void *)ttm;
struct mm_struct *mm = gtt->usertask->mm;
unsigned long start = gtt->userptr; unsigned long start = gtt->userptr;
struct vm_area_struct *vma; struct vm_area_struct *vma;
struct hmm_range *range; struct hmm_range *range;
unsigned long timeout;
struct mm_struct *mm;
unsigned long i; unsigned long i;
uint64_t *pfns;
int r = 0; int r = 0;
if (!mm) /* Happens during process shutdown */ mm = bo->notifier.mm;
if (unlikely(!mm)) {
DRM_DEBUG_DRIVER("BO is not registered?\n");
return -EFAULT;
}
/* Another get_user_pages is running at the same time?? */
if (WARN_ON(gtt->range))
return -EFAULT;
if (!mmget_not_zero(mm)) /* Happens during process shutdown */
return -ESRCH; return -ESRCH;
if (unlikely(!mirror)) {
DRM_DEBUG_DRIVER("Failed to get hmm_mirror\n");
r = -EFAULT;
goto out;
}
vma = find_vma(mm, start);
if (unlikely(!vma || start < vma->vm_start)) {
r = -EFAULT;
goto out;
}
if (unlikely((gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY) &&
vma->vm_file)) {
r = -EPERM;
goto out;
}
range = kzalloc(sizeof(*range), GFP_KERNEL); range = kzalloc(sizeof(*range), GFP_KERNEL);
if (unlikely(!range)) { if (unlikely(!range)) {
r = -ENOMEM; r = -ENOMEM;
goto out; goto out;
} }
range->notifier = &bo->notifier;
range->flags = hmm_range_flags;
range->values = hmm_range_values;
range->pfn_shift = PAGE_SHIFT;
range->start = bo->notifier.interval_tree.start;
range->end = bo->notifier.interval_tree.last + 1;
range->default_flags = hmm_range_flags[HMM_PFN_VALID];
if (!amdgpu_ttm_tt_is_readonly(ttm))
range->default_flags |= range->flags[HMM_PFN_WRITE];
pfns = kvmalloc_array(ttm->num_pages, sizeof(*pfns), GFP_KERNEL); range->pfns = kvmalloc_array(ttm->num_pages, sizeof(*range->pfns),
if (unlikely(!pfns)) { GFP_KERNEL);
if (unlikely(!range->pfns)) {
r = -ENOMEM; r = -ENOMEM;
goto out_free_ranges; goto out_free_ranges;
} }
amdgpu_hmm_init_range(range); down_read(&mm->mmap_sem);
range->default_flags = range->flags[HMM_PFN_VALID]; vma = find_vma(mm, start);
range->default_flags |= amdgpu_ttm_tt_is_readonly(ttm) ? if (unlikely(!vma || start < vma->vm_start)) {
0 : range->flags[HMM_PFN_WRITE]; r = -EFAULT;
range->pfn_flags_mask = 0; goto out_unlock;
range->pfns = pfns; }
range->start = start; if (unlikely((gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY) &&
range->end = start + ttm->num_pages * PAGE_SIZE; vma->vm_file)) {
r = -EPERM;
goto out_unlock;
}
up_read(&mm->mmap_sem);
timeout = jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
hmm_range_register(range, mirror); retry:
range->notifier_seq = mmu_interval_read_begin(&bo->notifier);
/*
* Just wait for range to be valid, safe to ignore return value as we
* will use the return value of hmm_range_fault() below under the
* mmap_sem to ascertain the validity of the range.
*/
hmm_range_wait_until_valid(range, HMM_RANGE_DEFAULT_TIMEOUT);
down_read(&mm->mmap_sem); down_read(&mm->mmap_sem);
r = hmm_range_fault(range, 0); r = hmm_range_fault(range, 0);
up_read(&mm->mmap_sem); up_read(&mm->mmap_sem);
if (unlikely(r <= 0)) {
if (unlikely(r < 0)) /*
* FIXME: This timeout should encompass the retry from
* mmu_interval_read_retry() as well.
*/
if ((r == 0 || r == -EBUSY) && !time_after(jiffies, timeout))
goto retry;
goto out_free_pfns; goto out_free_pfns;
}
for (i = 0; i < ttm->num_pages; i++) { for (i = 0; i < ttm->num_pages; i++) {
pages[i] = hmm_device_entry_to_page(range, pfns[i]); /* FIXME: The pages cannot be touched outside the notifier_lock */
pages[i] = hmm_device_entry_to_page(range, range->pfns[i]);
if (unlikely(!pages[i])) { if (unlikely(!pages[i])) {
pr_err("Page fault failed for pfn[%lu] = 0x%llx\n", pr_err("Page fault failed for pfn[%lu] = 0x%llx\n",
i, pfns[i]); i, range->pfns[i]);
r = -ENOMEM; r = -ENOMEM;
goto out_free_pfns; goto out_free_pfns;
@ -862,15 +881,18 @@ int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo, struct page **pages)
} }
gtt->range = range; gtt->range = range;
mmput(mm);
return 0; return 0;
out_unlock:
up_read(&mm->mmap_sem);
out_free_pfns: out_free_pfns:
hmm_range_unregister(range); kvfree(range->pfns);
kvfree(pfns);
out_free_ranges: out_free_ranges:
kfree(range); kfree(range);
out: out:
mmput(mm);
return r; return r;
} }
@ -895,15 +917,18 @@ bool amdgpu_ttm_tt_get_user_pages_done(struct ttm_tt *ttm)
"No user pages to check\n"); "No user pages to check\n");
if (gtt->range) { if (gtt->range) {
r = hmm_range_valid(gtt->range); /*
hmm_range_unregister(gtt->range); * FIXME: Must always hold notifier_lock for this, and must
* not ignore the return code.
*/
r = mmu_interval_read_retry(gtt->range->notifier,
gtt->range->notifier_seq);
kvfree(gtt->range->pfns); kvfree(gtt->range->pfns);
kfree(gtt->range); kfree(gtt->range);
gtt->range = NULL; gtt->range = NULL;
} }
return r; return !r;
} }
#endif #endif
@ -984,10 +1009,18 @@ static void amdgpu_ttm_tt_unpin_userptr(struct ttm_tt *ttm)
sg_free_table(ttm->sg); sg_free_table(ttm->sg);
#if IS_ENABLED(CONFIG_DRM_AMDGPU_USERPTR) #if IS_ENABLED(CONFIG_DRM_AMDGPU_USERPTR)
if (gtt->range && if (gtt->range) {
ttm->pages[0] == hmm_device_entry_to_page(gtt->range, unsigned long i;
gtt->range->pfns[0]))
WARN_ONCE(1, "Missing get_user_page_done\n"); for (i = 0; i < ttm->num_pages; i++) {
if (ttm->pages[i] !=
hmm_device_entry_to_page(gtt->range,
gtt->range->pfns[i]))
break;
}
WARN((i == ttm->num_pages), "Missing get_user_page_done\n");
}
#endif #endif
} }

226
drivers/gpu/drm/nouveau/nouveau_svm.c
View File

@ -88,6 +88,7 @@ nouveau_ivmm_find(struct nouveau_svm *svm, u64 inst)
} }
struct nouveau_svmm { struct nouveau_svmm {
struct mmu_notifier notifier;
struct nouveau_vmm *vmm; struct nouveau_vmm *vmm;
struct { struct {
unsigned long start; unsigned long start;
@ -95,9 +96,6 @@ struct nouveau_svmm {
} unmanaged; } unmanaged;
struct mutex mutex; struct mutex mutex;
struct mm_struct *mm;
struct hmm_mirror mirror;
}; };
#define SVMM_DBG(s,f,a...) \ #define SVMM_DBG(s,f,a...) \
@ -251,10 +249,11 @@ nouveau_svmm_invalidate(struct nouveau_svmm *svmm, u64 start, u64 limit)
} }
static int static int
nouveau_svmm_sync_cpu_device_pagetables(struct hmm_mirror *mirror, nouveau_svmm_invalidate_range_start(struct mmu_notifier *mn,
const struct mmu_notifier_range *update) const struct mmu_notifier_range *update)
{ {
struct nouveau_svmm *svmm = container_of(mirror, typeof(*svmm), mirror); struct nouveau_svmm *svmm =
container_of(mn, struct nouveau_svmm, notifier);
unsigned long start = update->start; unsigned long start = update->start;
unsigned long limit = update->end; unsigned long limit = update->end;
@ -264,6 +263,9 @@ nouveau_svmm_sync_cpu_device_pagetables(struct hmm_mirror *mirror,
SVMM_DBG(svmm, "invalidate %016lx-%016lx", start, limit); SVMM_DBG(svmm, "invalidate %016lx-%016lx", start, limit);
mutex_lock(&svmm->mutex); mutex_lock(&svmm->mutex);
if (unlikely(!svmm->vmm))
goto out;
if (limit > svmm->unmanaged.start && start < svmm->unmanaged.limit) { if (limit > svmm->unmanaged.start && start < svmm->unmanaged.limit) {
if (start < svmm->unmanaged.start) { if (start < svmm->unmanaged.start) {
nouveau_svmm_invalidate(svmm, start, nouveau_svmm_invalidate(svmm, start,
@ -273,19 +275,20 @@ nouveau_svmm_sync_cpu_device_pagetables(struct hmm_mirror *mirror,
} }
nouveau_svmm_invalidate(svmm, start, limit); nouveau_svmm_invalidate(svmm, start, limit);
out:
mutex_unlock(&svmm->mutex); mutex_unlock(&svmm->mutex);
return 0; return 0;
} }
static void static void nouveau_svmm_free_notifier(struct mmu_notifier *mn)
nouveau_svmm_release(struct hmm_mirror *mirror)
{ {
kfree(container_of(mn, struct nouveau_svmm, notifier));
} }
static const struct hmm_mirror_ops static const struct mmu_notifier_ops nouveau_mn_ops = {
nouveau_svmm = { .invalidate_range_start = nouveau_svmm_invalidate_range_start,
.sync_cpu_device_pagetables = nouveau_svmm_sync_cpu_device_pagetables, .free_notifier = nouveau_svmm_free_notifier,
.release = nouveau_svmm_release,
}; };
void void
@ -293,8 +296,10 @@ nouveau_svmm_fini(struct nouveau_svmm **psvmm)
{ {
struct nouveau_svmm *svmm = *psvmm; struct nouveau_svmm *svmm = *psvmm;
if (svmm) { if (svmm) {
hmm_mirror_unregister(&svmm->mirror); mutex_lock(&svmm->mutex);
kfree(*psvmm); svmm->vmm = NULL;
mutex_unlock(&svmm->mutex);
mmu_notifier_put(&svmm->notifier);
*psvmm = NULL; *psvmm = NULL;
} }
} }
@ -320,7 +325,7 @@ nouveau_svmm_init(struct drm_device *dev, void *data,
mutex_lock(&cli->mutex); mutex_lock(&cli->mutex);
if (cli->svm.cli) { if (cli->svm.cli) {
ret = -EBUSY; ret = -EBUSY;
goto done; goto out_free;
} }
/* Allocate a new GPU VMM that can support SVM (managed by the /* Allocate a new GPU VMM that can support SVM (managed by the
@ -335,24 +340,26 @@ nouveau_svmm_init(struct drm_device *dev, void *data,
.fault_replay = true, .fault_replay = true,
}, sizeof(struct gp100_vmm_v0), &cli->svm.vmm); }, sizeof(struct gp100_vmm_v0), &cli->svm.vmm);
if (ret) if (ret)
goto done; goto out_free;
down_write(&current->mm->mmap_sem);
svmm->notifier.ops = &nouveau_mn_ops;
ret = __mmu_notifier_register(&svmm->notifier, current->mm);
if (ret)
goto out_mm_unlock;
/* Note, ownership of svmm transfers to mmu_notifier */
/* Enable HMM mirroring of CPU address-space to VMM. */
svmm->mm = get_task_mm(current);
down_write(&svmm->mm->mmap_sem);
svmm->mirror.ops = &nouveau_svmm;
ret = hmm_mirror_register(&svmm->mirror, svmm->mm);
if (ret == 0) {
cli->svm.svmm = svmm; cli->svm.svmm = svmm;
cli->svm.cli = cli; cli->svm.cli = cli;
} up_write(&current->mm->mmap_sem);
up_write(&svmm->mm->mmap_sem);
mmput(svmm->mm);
done:
if (ret)
nouveau_svmm_fini(&svmm);
mutex_unlock(&cli->mutex); mutex_unlock(&cli->mutex);
return 0;
out_mm_unlock:
up_write(&current->mm->mmap_sem);
out_free:
mutex_unlock(&cli->mutex);
kfree(svmm);
return ret; return ret;
} }
@ -475,43 +482,90 @@ nouveau_svm_fault_cache(struct nouveau_svm *svm,
fault->inst, fault->addr, fault->access); fault->inst, fault->addr, fault->access);
} }
static inline bool struct svm_notifier {
nouveau_range_done(struct hmm_range *range) struct mmu_interval_notifier notifier;
{ struct nouveau_svmm *svmm;
bool ret = hmm_range_valid(range); };
hmm_range_unregister(range); static bool nouveau_svm_range_invalidate(struct mmu_interval_notifier *mni,
return ret; const struct mmu_notifier_range *range,
unsigned long cur_seq)
{
struct svm_notifier *sn =
container_of(mni, struct svm_notifier, notifier);
/*
* serializes the update to mni->invalidate_seq done by caller and
* prevents invalidation of the PTE from progressing while HW is being
* programmed. This is very hacky and only works because the normal
* notifier that does invalidation is always called after the range
* notifier.
*/
if (mmu_notifier_range_blockable(range))
mutex_lock(&sn->svmm->mutex);
else if (!mutex_trylock(&sn->svmm->mutex))
return false;
mmu_interval_set_seq(mni, cur_seq);
mutex_unlock(&sn->svmm->mutex);
return true;
} }
static int static const struct mmu_interval_notifier_ops nouveau_svm_mni_ops = {
nouveau_range_fault(struct nouveau_svmm *svmm, struct hmm_range *range) .invalidate = nouveau_svm_range_invalidate,
};
static int nouveau_range_fault(struct nouveau_svmm *svmm,
struct nouveau_drm *drm, void *data, u32 size,
u64 *pfns, struct svm_notifier *notifier)
{ {
unsigned long timeout =
jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
/* Have HMM fault pages within the fault window to the GPU. */
struct hmm_range range = {
.notifier = &notifier->notifier,
.start = notifier->notifier.interval_tree.start,
.end = notifier->notifier.interval_tree.last + 1,
.pfns = pfns,
.flags = nouveau_svm_pfn_flags,
.values = nouveau_svm_pfn_values,
.pfn_shift = NVIF_VMM_PFNMAP_V0_ADDR_SHIFT,
};
struct mm_struct *mm = notifier->notifier.mm;
long ret; long ret;
range->default_flags = 0; while (true) {
range->pfn_flags_mask = -1UL; if (time_after(jiffies, timeout))
ret = hmm_range_register(range, &svmm->mirror);
if (ret) {
up_read(&svmm->mm->mmap_sem);
return (int)ret;
}
if (!hmm_range_wait_until_valid(range, HMM_RANGE_DEFAULT_TIMEOUT)) {
up_read(&svmm->mm->mmap_sem);
return -EBUSY; return -EBUSY;
}
ret = hmm_range_fault(range, 0); range.notifier_seq = mmu_interval_read_begin(range.notifier);
range.default_flags = 0;
range.pfn_flags_mask = -1UL;
down_read(&mm->mmap_sem);
ret = hmm_range_fault(&range, 0);
up_read(&mm->mmap_sem);
if (ret <= 0) { if (ret <= 0) {
if (ret == 0) if (ret == 0 || ret == -EBUSY)
ret = -EBUSY; continue;
up_read(&svmm->mm->mmap_sem);
hmm_range_unregister(range);
return ret; return ret;
} }
return 0;
mutex_lock(&svmm->mutex);
if (mmu_interval_read_retry(range.notifier,
range.notifier_seq)) {
mutex_unlock(&svmm->mutex);
continue;
}
break;
}
nouveau_dmem_convert_pfn(drm, &range);
svmm->vmm->vmm.object.client->super = true;
ret = nvif_object_ioctl(&svmm->vmm->vmm.object, data, size, NULL);
svmm->vmm->vmm.object.client->super = false;
mutex_unlock(&svmm->mutex);
return ret;
} }
static int static int
@ -531,7 +585,6 @@ nouveau_svm_fault(struct nvif_notify *notify)
} i; } i;
u64 phys[16]; u64 phys[16];
} args; } args;
struct hmm_range range;
struct vm_area_struct *vma; struct vm_area_struct *vma;
u64 inst, start, limit; u64 inst, start, limit;
int fi, fn, pi, fill; int fi, fn, pi, fill;
@ -587,6 +640,9 @@ nouveau_svm_fault(struct nvif_notify *notify)
args.i.p.version = 0; args.i.p.version = 0;
for (fi = 0; fn = fi + 1, fi < buffer->fault_nr; fi = fn) { for (fi = 0; fn = fi + 1, fi < buffer->fault_nr; fi = fn) {
struct svm_notifier notifier;
struct mm_struct *mm;
/* Cancel any faults from non-SVM channels. */ /* Cancel any faults from non-SVM channels. */
if (!(svmm = buffer->fault[fi]->svmm)) { if (!(svmm = buffer->fault[fi]->svmm)) {
nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]); nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);
@ -606,24 +662,32 @@ nouveau_svm_fault(struct nvif_notify *notify)
start = max_t(u64, start, svmm->unmanaged.limit); start = max_t(u64, start, svmm->unmanaged.limit);
SVMM_DBG(svmm, "wndw %016llx-%016llx", start, limit); SVMM_DBG(svmm, "wndw %016llx-%016llx", start, limit);
mm = svmm->notifier.mm;
if (!mmget_not_zero(mm)) {
nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);
continue;
}
/* Intersect fault window with the CPU VMA, cancelling /* Intersect fault window with the CPU VMA, cancelling
* the fault if the address is invalid. * the fault if the address is invalid.
*/ */
down_read(&svmm->mm->mmap_sem); down_read(&mm->mmap_sem);
vma = find_vma_intersection(svmm->mm, start, limit); vma = find_vma_intersection(mm, start, limit);
if (!vma) { if (!vma) {
SVMM_ERR(svmm, "wndw %016llx-%016llx", start, limit); SVMM_ERR(svmm, "wndw %016llx-%016llx", start, limit);
up_read(&svmm->mm->mmap_sem); up_read(&mm->mmap_sem);
mmput(mm);
nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]); nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);
continue; continue;
} }
start = max_t(u64, start, vma->vm_start); start = max_t(u64, start, vma->vm_start);
limit = min_t(u64, limit, vma->vm_end); limit = min_t(u64, limit, vma->vm_end);
up_read(&mm->mmap_sem);
SVMM_DBG(svmm, "wndw %016llx-%016llx", start, limit); SVMM_DBG(svmm, "wndw %016llx-%016llx", start, limit);
if (buffer->fault[fi]->addr != start) { if (buffer->fault[fi]->addr != start) {
SVMM_ERR(svmm, "addr %016llx", buffer->fault[fi]->addr); SVMM_ERR(svmm, "addr %016llx", buffer->fault[fi]->addr);
up_read(&svmm->mm->mmap_sem); mmput(mm);
nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]); nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);
continue; continue;
} }
@ -679,33 +743,19 @@ nouveau_svm_fault(struct nvif_notify *notify)
args.i.p.addr, args.i.p.addr,
args.i.p.addr + args.i.p.size, fn - fi); args.i.p.addr + args.i.p.size, fn - fi);
/* Have HMM fault pages within the fault window to the GPU. */ notifier.svmm = svmm;
range.start = args.i.p.addr; ret = mmu_interval_notifier_insert(&notifier.notifier,
range.end = args.i.p.addr + args.i.p.size; svmm->notifier.mm,
range.pfns = args.phys; args.i.p.addr, args.i.p.size,
range.flags = nouveau_svm_pfn_flags; &nouveau_svm_mni_ops);
range.values = nouveau_svm_pfn_values; if (!ret) {
range.pfn_shift = NVIF_VMM_PFNMAP_V0_ADDR_SHIFT; ret = nouveau_range_fault(
again: svmm, svm->drm, &args,
ret = nouveau_range_fault(svmm, &range); sizeof(args.i) + pi * sizeof(args.phys[0]),
if (ret == 0) { args.phys, &notifier);
mutex_lock(&svmm->mutex); mmu_interval_notifier_remove(&notifier.notifier);
if (!nouveau_range_done(&range)) {
mutex_unlock(&svmm->mutex);
goto again;
}
nouveau_dmem_convert_pfn(svm->drm, &range);
svmm->vmm->vmm.object.client->super = true;
ret = nvif_object_ioctl(&svmm->vmm->vmm.object,
&args, sizeof(args.i) +
pi * sizeof(args.phys[0]),
NULL);
svmm->vmm->vmm.object.client->super = false;
mutex_unlock(&svmm->mutex);
up_read(&svmm->mm->mmap_sem);
} }
mmput(mm);
/* Cancel any faults in the window whose pages didn't manage /* Cancel any faults in the window whose pages didn't manage
* to keep their valid bit, or stay writeable when required. * to keep their valid bit, or stay writeable when required.
@ -714,10 +764,10 @@ again:
*/ */
while (fi < fn) { while (fi < fn) {
struct nouveau_svm_fault *fault = buffer->fault[fi++]; struct nouveau_svm_fault *fault = buffer->fault[fi++];
pi = (fault->addr - range.start) >> PAGE_SHIFT; pi = (fault->addr - args.i.p.addr) >> PAGE_SHIFT;
if (ret || if (ret ||
!(range.pfns[pi] & NVIF_VMM_PFNMAP_V0_V) || !(args.phys[pi] & NVIF_VMM_PFNMAP_V0_V) ||
(!(range.pfns[pi] & NVIF_VMM_PFNMAP_V0_W) && (!(args.phys[pi] & NVIF_VMM_PFNMAP_V0_W) &&
fault->access != 0 && fault->access != 3)) { fault->access != 0 && fault->access != 3)) {
nouveau_svm_fault_cancel_fault(svm, fault); nouveau_svm_fault_cancel_fault(svm, fault);
continue; continue;

9
drivers/gpu/drm/radeon/radeon.h
View File

@ -68,6 +68,10 @@
#include <linux/hashtable.h> #include <linux/hashtable.h>
#include <linux/dma-fence.h> #include <linux/dma-fence.h>
#ifdef CONFIG_MMU_NOTIFIER
#include <linux/mmu_notifier.h>
#endif
#include <drm/ttm/ttm_bo_api.h> #include <drm/ttm/ttm_bo_api.h>
#include <drm/ttm/ttm_bo_driver.h> #include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_placement.h> #include <drm/ttm/ttm_placement.h>
@ -509,8 +513,9 @@ struct radeon_bo {
struct ttm_bo_kmap_obj dma_buf_vmap; struct ttm_bo_kmap_obj dma_buf_vmap;
pid_t pid; pid_t pid;
struct radeon_mn *mn; #ifdef CONFIG_MMU_NOTIFIER
struct list_head mn_list; struct mmu_interval_notifier notifier;
#endif
}; };
#define gem_to_radeon_bo(gobj) container_of((gobj), struct radeon_bo, tbo.base) #define gem_to_radeon_bo(gobj) container_of((gobj), struct radeon_bo, tbo.base)

192
drivers/gpu/drm/radeon/radeon_mn.c
View File

@ -36,77 +36,37 @@
#include "radeon.h" #include "radeon.h"
struct radeon_mn {
struct mmu_notifier mn;
/* objects protected by lock */
struct mutex lock;
struct rb_root_cached objects;
};
struct radeon_mn_node {
struct interval_tree_node it;
struct list_head bos;
};
/** /**
* radeon_mn_invalidate_range_start - callback to notify about mm change * radeon_mn_invalidate - callback to notify about mm change
* *
* @mn: our notifier * @mn: our notifier
* @mn: the mm this callback is about * @range: the VMA under invalidation
* @start: start of updated range
* @end: end of updated range
* *
* We block for all BOs between start and end to be idle and * We block for all BOs between start and end to be idle and
* unmap them by move them into system domain again. * unmap them by move them into system domain again.
*/ */
static int radeon_mn_invalidate_range_start(struct mmu_notifier *mn, static bool radeon_mn_invalidate(struct mmu_interval_notifier *mn,
const struct mmu_notifier_range *range) const struct mmu_notifier_range *range,
unsigned long cur_seq)
{ {
struct radeon_mn *rmn = container_of(mn, struct radeon_mn, mn); struct radeon_bo *bo = container_of(mn, struct radeon_bo, notifier);
struct ttm_operation_ctx ctx = { false, false }; struct ttm_operation_ctx ctx = { false, false };
struct interval_tree_node *it;
unsigned long end;
int ret = 0;
/* notification is exclusive, but interval is inclusive */
end = range->end - 1;
/* TODO we should be able to split locking for interval tree and
* the tear down.
*/
if (mmu_notifier_range_blockable(range))
mutex_lock(&rmn->lock);
else if (!mutex_trylock(&rmn->lock))
return -EAGAIN;
it = interval_tree_iter_first(&rmn->objects, range->start, end);
while (it) {
struct radeon_mn_node *node;
struct radeon_bo *bo;
long r; long r;
if (!mmu_notifier_range_blockable(range)) {
ret = -EAGAIN;
goto out_unlock;
}
node = container_of(it, struct radeon_mn_node, it);
it = interval_tree_iter_next(it, range->start, end);
list_for_each_entry(bo, &node->bos, mn_list) {
if (!bo->tbo.ttm || bo->tbo.ttm->state != tt_bound) if (!bo->tbo.ttm || bo->tbo.ttm->state != tt_bound)
continue; return true;
if (!mmu_notifier_range_blockable(range))
return false;
r = radeon_bo_reserve(bo, true); r = radeon_bo_reserve(bo, true);
if (r) { if (r) {
DRM_ERROR("(%ld) failed to reserve user bo\n", r); DRM_ERROR("(%ld) failed to reserve user bo\n", r);
continue; return true;
} }
r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, true, false,
true, false, MAX_SCHEDULE_TIMEOUT); MAX_SCHEDULE_TIMEOUT);
if (r <= 0) if (r <= 0)
DRM_ERROR("(%ld) failed to wait for user bo\n", r); DRM_ERROR("(%ld) failed to wait for user bo\n", r);
@ -116,51 +76,11 @@ static int radeon_mn_invalidate_range_start(struct mmu_notifier *mn,
DRM_ERROR("(%ld) failed to validate user bo\n", r); DRM_ERROR("(%ld) failed to validate user bo\n", r);
radeon_bo_unreserve(bo); radeon_bo_unreserve(bo);
} return true;
}
out_unlock:
mutex_unlock(&rmn->lock);
return ret;
} }
static void radeon_mn_release(struct mmu_notifier *mn, struct mm_struct *mm) static const struct mmu_interval_notifier_ops radeon_mn_ops = {
{ .invalidate = radeon_mn_invalidate,
struct mmu_notifier_range range = {
.mm = mm,
.start = 0,
.end = ULONG_MAX,
.flags = 0,
.event = MMU_NOTIFY_UNMAP,
};
radeon_mn_invalidate_range_start(mn, &range);
}
static struct mmu_notifier *radeon_mn_alloc_notifier(struct mm_struct *mm)
{
struct radeon_mn *rmn;
rmn = kzalloc(sizeof(*rmn), GFP_KERNEL);
if (!rmn)
return ERR_PTR(-ENOMEM);
mutex_init(&rmn->lock);
rmn->objects = RB_ROOT_CACHED;
return &rmn->mn;
}
static void radeon_mn_free_notifier(struct mmu_notifier *mn)
{
kfree(container_of(mn, struct radeon_mn, mn));
}
static const struct mmu_notifier_ops radeon_mn_ops = {
.release = radeon_mn_release,
.invalidate_range_start = radeon_mn_invalidate_range_start,
.alloc_notifier = radeon_mn_alloc_notifier,
.free_notifier = radeon_mn_free_notifier,
}; };
/** /**
@ -174,51 +94,20 @@ static const struct mmu_notifier_ops radeon_mn_ops = {
*/ */
int radeon_mn_register(struct radeon_bo *bo, unsigned long addr) int radeon_mn_register(struct radeon_bo *bo, unsigned long addr)
{ {
unsigned long end = addr + radeon_bo_size(bo) - 1; int ret;
struct mmu_notifier *mn;
struct radeon_mn *rmn;
struct radeon_mn_node *node = NULL;
struct list_head bos;
struct interval_tree_node *it;
mn = mmu_notifier_get(&radeon_mn_ops, current->mm); ret = mmu_interval_notifier_insert(&bo->notifier, current->mm, addr,
if (IS_ERR(mn)) radeon_bo_size(bo), &radeon_mn_ops);
return PTR_ERR(mn); if (ret)
rmn = container_of(mn, struct radeon_mn, mn); return ret;
INIT_LIST_HEAD(&bos);
mutex_lock(&rmn->lock);
while ((it = interval_tree_iter_first(&rmn->objects, addr, end))) {
kfree(node);
node = container_of(it, struct radeon_mn_node, it);
interval_tree_remove(&node->it, &rmn->objects);
addr = min(it->start, addr);
end = max(it->last, end);
list_splice(&node->bos, &bos);
}
if (!node) {
node = kmalloc(sizeof(struct radeon_mn_node), GFP_KERNEL);
if (!node) {
mutex_unlock(&rmn->lock);
return -ENOMEM;
}
}
bo->mn = rmn;
node->it.start = addr;
node->it.last = end;
INIT_LIST_HEAD(&node->bos);
list_splice(&bos, &node->bos);
list_add(&bo->mn_list, &node->bos);
interval_tree_insert(&node->it, &rmn->objects);
mutex_unlock(&rmn->lock);
/*
* FIXME: radeon appears to allow get_user_pages to run during
* invalidate_range_start/end, which is not a safe way to read the
* PTEs. It should use the mmu_interval_read_begin() scheme around the
* get_user_pages to ensure that the PTEs are read properly
*/
mmu_interval_read_begin(&bo->notifier);
return 0; return 0;
} }
@ -231,27 +120,8 @@ int radeon_mn_register(struct radeon_bo *bo, unsigned long addr)
*/ */
void radeon_mn_unregister(struct radeon_bo *bo) void radeon_mn_unregister(struct radeon_bo *bo)
{ {
struct radeon_mn *rmn = bo->mn; if (!bo->notifier.mm)
struct list_head *head;
if (!rmn)
return; return;
mmu_interval_notifier_remove(&bo->notifier);
mutex_lock(&rmn->lock); bo->notifier.mm = NULL;
/* save the next list entry for later */
head = bo->mn_list.next;
list_del(&bo->mn_list);
if (list_empty(head)) {
struct radeon_mn_node *node;
node = container_of(head, struct radeon_mn_node, bos);
interval_tree_remove(&node->it, &rmn->objects);
kfree(node);
}
mutex_unlock(&rmn->lock);
mmu_notifier_put(&rmn->mn);
bo->mn = NULL;
} }

1
drivers/infiniband/core/device.c
View File

@ -2634,7 +2634,6 @@ void ib_set_device_ops(struct ib_device *dev, const struct ib_device_ops *ops)
SET_DEVICE_OP(dev_ops, get_vf_guid); SET_DEVICE_OP(dev_ops, get_vf_guid);
SET_DEVICE_OP(dev_ops, get_vf_stats); SET_DEVICE_OP(dev_ops, get_vf_stats);
SET_DEVICE_OP(dev_ops, init_port); SET_DEVICE_OP(dev_ops, init_port);
SET_DEVICE_OP(dev_ops, invalidate_range);
SET_DEVICE_OP(dev_ops, iw_accept); SET_DEVICE_OP(dev_ops, iw_accept);
SET_DEVICE_OP(dev_ops, iw_add_ref); SET_DEVICE_OP(dev_ops, iw_add_ref);
SET_DEVICE_OP(dev_ops, iw_connect); SET_DEVICE_OP(dev_ops, iw_connect);

301
drivers/infiniband/core/umem_odp.c
View File

@ -48,197 +48,33 @@
#include "uverbs.h" #include "uverbs.h"
static void ib_umem_notifier_start_account(struct ib_umem_odp *umem_odp) static inline int ib_init_umem_odp(struct ib_umem_odp *umem_odp,
const struct mmu_interval_notifier_ops *ops)
{ {
mutex_lock(&umem_odp->umem_mutex);
if (umem_odp->notifiers_count++ == 0)
/*
* Initialize the completion object for waiting on
* notifiers. Since notifier_count is zero, no one should be
* waiting right now.
*/
reinit_completion(&umem_odp->notifier_completion);
mutex_unlock(&umem_odp->umem_mutex);
}
static void ib_umem_notifier_end_account(struct ib_umem_odp *umem_odp)
{
mutex_lock(&umem_odp->umem_mutex);
/*
* This sequence increase will notify the QP page fault that the page
* that is going to be mapped in the spte could have been freed.
*/
++umem_odp->notifiers_seq;
if (--umem_odp->notifiers_count == 0)
complete_all(&umem_odp->notifier_completion);
mutex_unlock(&umem_odp->umem_mutex);
}
static void ib_umem_notifier_release(struct mmu_notifier *mn,
struct mm_struct *mm)
{
struct ib_ucontext_per_mm *per_mm =
container_of(mn, struct ib_ucontext_per_mm, mn);
struct rb_node *node;
down_read(&per_mm->umem_rwsem);
if (!per_mm->mn.users)
goto out;
for (node = rb_first_cached(&per_mm->umem_tree); node;
node = rb_next(node)) {
struct ib_umem_odp *umem_odp =
rb_entry(node, struct ib_umem_odp, interval_tree.rb);
/*
* Increase the number of notifiers running, to prevent any
* further fault handling on this MR.
*/
ib_umem_notifier_start_account(umem_odp);
complete_all(&umem_odp->notifier_completion);
umem_odp->umem.ibdev->ops.invalidate_range(
umem_odp, ib_umem_start(umem_odp),
ib_umem_end(umem_odp));
}
out:
up_read(&per_mm->umem_rwsem);
}
static int invalidate_range_start_trampoline(struct ib_umem_odp *item,
u64 start, u64 end, void *cookie)
{
ib_umem_notifier_start_account(item);
item->umem.ibdev->ops.invalidate_range(item, start, end);
return 0;
}
static int ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn,
const struct mmu_notifier_range *range)
{
struct ib_ucontext_per_mm *per_mm =
container_of(mn, struct ib_ucontext_per_mm, mn);
int rc;
if (mmu_notifier_range_blockable(range))
down_read(&per_mm->umem_rwsem);
else if (!down_read_trylock(&per_mm->umem_rwsem))
return -EAGAIN;
if (!per_mm->mn.users) {
up_read(&per_mm->umem_rwsem);
/*
* At this point users is permanently zero and visible to this
* CPU without a lock, that fact is relied on to skip the unlock
* in range_end.
*/
return 0;
}
rc = rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, range->start,
range->end,
invalidate_range_start_trampoline,
mmu_notifier_range_blockable(range),
NULL);
if (rc)
up_read(&per_mm->umem_rwsem);
return rc;
}
static int invalidate_range_end_trampoline(struct ib_umem_odp *item, u64 start,
u64 end, void *cookie)
{
ib_umem_notifier_end_account(item);
return 0;
}
static void ib_umem_notifier_invalidate_range_end(struct mmu_notifier *mn,
const struct mmu_notifier_range *range)
{
struct ib_ucontext_per_mm *per_mm =
container_of(mn, struct ib_ucontext_per_mm, mn);
if (unlikely(!per_mm->mn.users))
return;
rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, range->start,
range->end,
invalidate_range_end_trampoline, true, NULL);
up_read(&per_mm->umem_rwsem);
}
static struct mmu_notifier *ib_umem_alloc_notifier(struct mm_struct *mm)
{
struct ib_ucontext_per_mm *per_mm;
per_mm = kzalloc(sizeof(*per_mm), GFP_KERNEL);
if (!per_mm)
return ERR_PTR(-ENOMEM);
per_mm->umem_tree = RB_ROOT_CACHED;
init_rwsem(&per_mm->umem_rwsem);
WARN_ON(mm != current->mm);
rcu_read_lock();
per_mm->tgid = get_task_pid(current->group_leader, PIDTYPE_PID);
rcu_read_unlock();
return &per_mm->mn;
}
static void ib_umem_free_notifier(struct mmu_notifier *mn)
{
struct ib_ucontext_per_mm *per_mm =
container_of(mn, struct ib_ucontext_per_mm, mn);
WARN_ON(!RB_EMPTY_ROOT(&per_mm->umem_tree.rb_root));
put_pid(per_mm->tgid);
kfree(per_mm);
}
static const struct mmu_notifier_ops ib_umem_notifiers = {
.release = ib_umem_notifier_release,
.invalidate_range_start = ib_umem_notifier_invalidate_range_start,
.invalidate_range_end = ib_umem_notifier_invalidate_range_end,
.alloc_notifier = ib_umem_alloc_notifier,
.free_notifier = ib_umem_free_notifier,
};
static inline int ib_init_umem_odp(struct ib_umem_odp *umem_odp)
{
struct ib_ucontext_per_mm *per_mm;
struct mmu_notifier *mn;
int ret; int ret;
umem_odp->umem.is_odp = 1; umem_odp->umem.is_odp = 1;
mutex_init(&umem_odp->umem_mutex);
if (!umem_odp->is_implicit_odp) { if (!umem_odp->is_implicit_odp) {
size_t page_size = 1UL << umem_odp->page_shift; size_t page_size = 1UL << umem_odp->page_shift;
unsigned long start;
unsigned long end;
size_t pages; size_t pages;
umem_odp->interval_tree.start = start = ALIGN_DOWN(umem_odp->umem.address, page_size);
ALIGN_DOWN(umem_odp->umem.address, page_size);
if (check_add_overflow(umem_odp->umem.address, if (check_add_overflow(umem_odp->umem.address,
(unsigned long)umem_odp->umem.length, (unsigned long)umem_odp->umem.length,
&umem_odp->interval_tree.last)) &end))
return -EOVERFLOW; return -EOVERFLOW;
umem_odp->interval_tree.last = end = ALIGN(end, page_size);
ALIGN(umem_odp->interval_tree.last, page_size); if (unlikely(end < page_size))
if (unlikely(umem_odp->interval_tree.last < page_size))
return -EOVERFLOW; return -EOVERFLOW;
pages = (umem_odp->interval_tree.last - pages = (end - start) >> umem_odp->page_shift;
umem_odp->interval_tree.start) >>
umem_odp->page_shift;
if (!pages) if (!pages)
return -EINVAL; return -EINVAL;
/*
* Note that the representation of the intervals in the
* interval tree considers the ending point as contained in
* the interval.
*/
umem_odp->interval_tree.last--;
umem_odp->page_list = kvcalloc( umem_odp->page_list = kvcalloc(
pages, sizeof(*umem_odp->page_list), GFP_KERNEL); pages, sizeof(*umem_odp->page_list), GFP_KERNEL);
if (!umem_odp->page_list) if (!umem_odp->page_list)
@ -250,26 +86,13 @@ static inline int ib_init_umem_odp(struct ib_umem_odp *umem_odp)
ret = -ENOMEM; ret = -ENOMEM;
goto out_page_list; goto out_page_list;
} }
}
mn = mmu_notifier_get(&ib_umem_notifiers, umem_odp->umem.owning_mm); ret = mmu_interval_notifier_insert(&umem_odp->notifier,
if (IS_ERR(mn)) { umem_odp->umem.owning_mm,
ret = PTR_ERR(mn); start, end - start, ops);
if (ret)
goto out_dma_list; goto out_dma_list;
} }
umem_odp->per_mm = per_mm =
container_of(mn, struct ib_ucontext_per_mm, mn);
mutex_init(&umem_odp->umem_mutex);
init_completion(&umem_odp->notifier_completion);
if (!umem_odp->is_implicit_odp) {
down_write(&per_mm->umem_rwsem);
interval_tree_insert(&umem_odp->interval_tree,
&per_mm->umem_tree);
up_write(&per_mm->umem_rwsem);
}
mmgrab(umem_odp->umem.owning_mm);
return 0; return 0;
@ -305,8 +128,6 @@ struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_udata *udata,
if (!context) if (!context)
return ERR_PTR(-EIO); return ERR_PTR(-EIO);
if (WARN_ON_ONCE(!context->device->ops.invalidate_range))
return ERR_PTR(-EINVAL);
umem_odp = kzalloc(sizeof(*umem_odp), GFP_KERNEL); umem_odp = kzalloc(sizeof(*umem_odp), GFP_KERNEL);
if (!umem_odp) if (!umem_odp)
@ -318,8 +139,10 @@ struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_udata *udata,
umem_odp->is_implicit_odp = 1; umem_odp->is_implicit_odp = 1;
umem_odp->page_shift = PAGE_SHIFT; umem_odp->page_shift = PAGE_SHIFT;
ret = ib_init_umem_odp(umem_odp); umem_odp->tgid = get_task_pid(current->group_leader, PIDTYPE_PID);
ret = ib_init_umem_odp(umem_odp, NULL);
if (ret) { if (ret) {
put_pid(umem_odp->tgid);
kfree(umem_odp); kfree(umem_odp);
return ERR_PTR(ret); return ERR_PTR(ret);
} }
@ -336,8 +159,10 @@ EXPORT_SYMBOL(ib_umem_odp_alloc_implicit);
* @addr: The starting userspace VA * @addr: The starting userspace VA
* @size: The length of the userspace VA * @size: The length of the userspace VA
*/ */
struct ib_umem_odp *ib_umem_odp_alloc_child(struct ib_umem_odp *root, struct ib_umem_odp *
unsigned long addr, size_t size) ib_umem_odp_alloc_child(struct ib_umem_odp *root, unsigned long addr,
size_t size,
const struct mmu_interval_notifier_ops *ops)
{ {
/* /*
* Caller must ensure that root cannot be freed during the call to * Caller must ensure that root cannot be freed during the call to
@ -360,9 +185,12 @@ struct ib_umem_odp *ib_umem_odp_alloc_child(struct ib_umem_odp *root,
umem->writable = root->umem.writable; umem->writable = root->umem.writable;
umem->owning_mm = root->umem.owning_mm; umem->owning_mm = root->umem.owning_mm;
odp_data->page_shift = PAGE_SHIFT; odp_data->page_shift = PAGE_SHIFT;
odp_data->notifier.ops = ops;
ret = ib_init_umem_odp(odp_data); odp_data->tgid = get_pid(root->tgid);
ret = ib_init_umem_odp(odp_data, ops);
if (ret) { if (ret) {
put_pid(odp_data->tgid);
kfree(odp_data); kfree(odp_data);
return ERR_PTR(ret); return ERR_PTR(ret);
} }
@ -383,7 +211,8 @@ EXPORT_SYMBOL(ib_umem_odp_alloc_child);
* conjunction with MMU notifiers. * conjunction with MMU notifiers.
*/ */
struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata, unsigned long addr, struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata, unsigned long addr,
size_t size, int access) size_t size, int access,
const struct mmu_interval_notifier_ops *ops)
{ {
struct ib_umem_odp *umem_odp; struct ib_umem_odp *umem_odp;
struct ib_ucontext *context; struct ib_ucontext *context;
@ -398,8 +227,7 @@ struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata, unsigned long addr,
if (!context) if (!context)
return ERR_PTR(-EIO); return ERR_PTR(-EIO);
if (WARN_ON_ONCE(!(access & IB_ACCESS_ON_DEMAND)) || if (WARN_ON_ONCE(!(access & IB_ACCESS_ON_DEMAND)))
WARN_ON_ONCE(!context->device->ops.invalidate_range))
return ERR_PTR(-EINVAL); return ERR_PTR(-EINVAL);
umem_odp = kzalloc(sizeof(struct ib_umem_odp), GFP_KERNEL); umem_odp = kzalloc(sizeof(struct ib_umem_odp), GFP_KERNEL);
@ -411,6 +239,7 @@ struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata, unsigned long addr,
umem_odp->umem.address = addr; umem_odp->umem.address = addr;
umem_odp->umem.writable = ib_access_writable(access); umem_odp->umem.writable = ib_access_writable(access);
umem_odp->umem.owning_mm = mm = current->mm; umem_odp->umem.owning_mm = mm = current->mm;
umem_odp->notifier.ops = ops;
umem_odp->page_shift = PAGE_SHIFT; umem_odp->page_shift = PAGE_SHIFT;
if (access & IB_ACCESS_HUGETLB) { if (access & IB_ACCESS_HUGETLB) {
@ -429,11 +258,14 @@ struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata, unsigned long addr,
up_read(&mm->mmap_sem); up_read(&mm->mmap_sem);
} }
ret = ib_init_umem_odp(umem_odp); umem_odp->tgid = get_task_pid(current->group_leader, PIDTYPE_PID);
ret = ib_init_umem_odp(umem_odp, ops);
if (ret) if (ret)
goto err_free; goto err_put_pid;
return umem_odp; return umem_odp;
err_put_pid:
put_pid(umem_odp->tgid);
err_free: err_free:
kfree(umem_odp); kfree(umem_odp);
return ERR_PTR(ret); return ERR_PTR(ret);
@ -442,8 +274,6 @@ EXPORT_SYMBOL(ib_umem_odp_get);
void ib_umem_odp_release(struct ib_umem_odp *umem_odp) void ib_umem_odp_release(struct ib_umem_odp *umem_odp)
{ {
struct ib_ucontext_per_mm *per_mm = umem_odp->per_mm;
/* /*
* Ensure that no more pages are mapped in the umem. * Ensure that no more pages are mapped in the umem.
* *
@ -455,28 +285,11 @@ void ib_umem_odp_release(struct ib_umem_odp *umem_odp)
ib_umem_odp_unmap_dma_pages(umem_odp, ib_umem_start(umem_odp), ib_umem_odp_unmap_dma_pages(umem_odp, ib_umem_start(umem_odp),
ib_umem_end(umem_odp)); ib_umem_end(umem_odp));
mutex_unlock(&umem_odp->umem_mutex); mutex_unlock(&umem_odp->umem_mutex);
mmu_interval_notifier_remove(&umem_odp->notifier);
kvfree(umem_odp->dma_list); kvfree(umem_odp->dma_list);
kvfree(umem_odp->page_list); kvfree(umem_odp->page_list);
put_pid(umem_odp->tgid);
} }
down_write(&per_mm->umem_rwsem);
if (!umem_odp->is_implicit_odp) {
interval_tree_remove(&umem_odp->interval_tree,
&per_mm->umem_tree);
complete_all(&umem_odp->notifier_completion);
}
/*
* NOTE! mmu_notifier_unregister() can happen between a start/end
* callback, resulting in a missing end, and thus an unbalanced
* lock. This doesn't really matter to us since we are about to kfree
* the memory that holds the lock, however LOCKDEP doesn't like this.
* Thus we call the mmu_notifier_put under the rwsem and test the
* internal users count to reliably see if we are past this point.
*/
mmu_notifier_put(&per_mm->mn);
up_write(&per_mm->umem_rwsem);
mmdrop(umem_odp->umem.owning_mm);
kfree(umem_odp); kfree(umem_odp);
} }
EXPORT_SYMBOL(ib_umem_odp_release); EXPORT_SYMBOL(ib_umem_odp_release);
@ -501,7 +314,7 @@ EXPORT_SYMBOL(ib_umem_odp_release);
*/ */
static int ib_umem_odp_map_dma_single_page( static int ib_umem_odp_map_dma_single_page(
struct ib_umem_odp *umem_odp, struct ib_umem_odp *umem_odp,
int page_index, unsigned int page_index,
struct page *page, struct page *page,
u64 access_mask, u64 access_mask,
unsigned long current_seq) unsigned long current_seq)
@ -510,12 +323,7 @@ static int ib_umem_odp_map_dma_single_page(
dma_addr_t dma_addr; dma_addr_t dma_addr;
int ret = 0; int ret = 0;
/* if (mmu_interval_check_retry(&umem_odp->notifier, current_seq)) {
* Note: we avoid writing if seq is different from the initial seq, to
* handle case of a racing notifier. This check also allows us to bail
* early if we have a notifier running in parallel with us.
*/
if (ib_umem_mmu_notifier_retry(umem_odp, current_seq)) {
ret = -EAGAIN; ret = -EAGAIN;
goto out; goto out;
} }
@ -618,7 +426,7 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 user_virt,
* existing beyond the lifetime of the originating process.. Presumably * existing beyond the lifetime of the originating process.. Presumably
* mmget_not_zero will fail in this case. * mmget_not_zero will fail in this case.
*/ */
owning_process = get_pid_task(umem_odp->per_mm->tgid, PIDTYPE_PID); owning_process = get_pid_task(umem_odp->tgid, PIDTYPE_PID);
if (!owning_process || !mmget_not_zero(owning_mm)) { if (!owning_process || !mmget_not_zero(owning_mm)) {
ret = -EINVAL; ret = -EINVAL;
goto out_put_task; goto out_put_task;
@ -762,32 +570,3 @@ void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 virt,
} }
} }
EXPORT_SYMBOL(ib_umem_odp_unmap_dma_pages); EXPORT_SYMBOL(ib_umem_odp_unmap_dma_pages);
/* @last is not a part of the interval. See comment for function
* node_last.
*/
int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root,
u64 start, u64 last,
umem_call_back cb,
bool blockable,
void *cookie)
{
int ret_val = 0;
struct interval_tree_node *node, *next;
struct ib_umem_odp *umem;
if (unlikely(start == last))
return ret_val;
for (node = interval_tree_iter_first(root, start, last - 1);
node; node = next) {
/* TODO move the blockable decision up to the callback */
if (!blockable)
return -EAGAIN;
next = interval_tree_iter_next(node, start, last - 1);
umem = container_of(node, struct ib_umem_odp, interval_tree);
ret_val = cb(umem, start, last, cookie) || ret_val;
}
return ret_val;
}

2
drivers/infiniband/hw/hfi1/file_ops.c
View File

@ -1138,7 +1138,7 @@ static int get_ctxt_info(struct hfi1_filedata *fd, unsigned long arg, u32 len)
HFI1_CAP_UGET_MASK(uctxt->flags, MASK) | HFI1_CAP_UGET_MASK(uctxt->flags, MASK) |
HFI1_CAP_KGET_MASK(uctxt->flags, K2U); HFI1_CAP_KGET_MASK(uctxt->flags, K2U);
/* adjust flag if this fd is not able to cache */ /* adjust flag if this fd is not able to cache */
if (!fd->handler) if (!fd->use_mn)
cinfo.runtime_flags |= HFI1_CAP_TID_UNMAP; /* no caching */ cinfo.runtime_flags |= HFI1_CAP_TID_UNMAP; /* no caching */
cinfo.num_active = hfi1_count_active_units(); cinfo.num_active = hfi1_count_active_units();

2
drivers/infiniband/hw/hfi1/hfi.h
View File

@ -1444,7 +1444,7 @@ struct hfi1_filedata {
/* for cpu affinity; -1 if none */ /* for cpu affinity; -1 if none */
int rec_cpu_num; int rec_cpu_num;
u32 tid_n_pinned; u32 tid_n_pinned;
struct mmu_rb_handler *handler; bool use_mn;
struct tid_rb_node **entry_to_rb; struct tid_rb_node **entry_to_rb;
spinlock_t tid_lock; /* protect tid_[limit,used] counters */ spinlock_t tid_lock; /* protect tid_[limit,used] counters */
u32 tid_limit; u32 tid_limit;

132
drivers/infiniband/hw/hfi1/user_exp_rcv.c
View File

@ -59,11 +59,11 @@ static int set_rcvarray_entry(struct hfi1_filedata *fd,
struct tid_user_buf *tbuf, struct tid_user_buf *tbuf,
u32 rcventry, struct tid_group *grp, u32 rcventry, struct tid_group *grp,
u16 pageidx, unsigned int npages); u16 pageidx, unsigned int npages);
static int tid_rb_insert(void *arg, struct mmu_rb_node *node);
static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata, static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
struct tid_rb_node *tnode); struct tid_rb_node *tnode);
static void tid_rb_remove(void *arg, struct mmu_rb_node *node); static bool tid_rb_invalidate(struct mmu_interval_notifier *mni,
static int tid_rb_invalidate(void *arg, struct mmu_rb_node *mnode); const struct mmu_notifier_range *range,
unsigned long cur_seq);
static int program_rcvarray(struct hfi1_filedata *fd, struct tid_user_buf *, static int program_rcvarray(struct hfi1_filedata *fd, struct tid_user_buf *,
struct tid_group *grp, struct tid_group *grp,
unsigned int start, u16 count, unsigned int start, u16 count,
@ -73,10 +73,8 @@ static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
struct tid_group **grp); struct tid_group **grp);
static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node); static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node);
static struct mmu_rb_ops tid_rb_ops = { static const struct mmu_interval_notifier_ops tid_mn_ops = {
.insert = tid_rb_insert, .invalidate = tid_rb_invalidate,
.remove = tid_rb_remove,
.invalidate = tid_rb_invalidate
}; };
/* /*
@ -87,7 +85,6 @@ static struct mmu_rb_ops tid_rb_ops = {
int hfi1_user_exp_rcv_init(struct hfi1_filedata *fd, int hfi1_user_exp_rcv_init(struct hfi1_filedata *fd,
struct hfi1_ctxtdata *uctxt) struct hfi1_ctxtdata *uctxt)
{ {
struct hfi1_devdata *dd = uctxt->dd;
int ret = 0; int ret = 0;
spin_lock_init(&fd->tid_lock); spin_lock_init(&fd->tid_lock);
@ -109,20 +106,7 @@ int hfi1_user_exp_rcv_init(struct hfi1_filedata *fd,
fd->entry_to_rb = NULL; fd->entry_to_rb = NULL;
return -ENOMEM; return -ENOMEM;
} }
fd->use_mn = true;
/*
* Register MMU notifier callbacks. If the registration
* fails, continue without TID caching for this context.
*/
ret = hfi1_mmu_rb_register(fd, fd->mm, &tid_rb_ops,
dd->pport->hfi1_wq,
&fd->handler);
if (ret) {
dd_dev_info(dd,
"Failed MMU notifier registration %d\n",
ret);
ret = 0;
}
} }
/* /*
@ -139,7 +123,7 @@ int hfi1_user_exp_rcv_init(struct hfi1_filedata *fd,
* init. * init.
*/ */
spin_lock(&fd->tid_lock); spin_lock(&fd->tid_lock);
if (uctxt->subctxt_cnt && fd->handler) { if (uctxt->subctxt_cnt && fd->use_mn) {
u16 remainder; u16 remainder;
fd->tid_limit = uctxt->expected_count / uctxt->subctxt_cnt; fd->tid_limit = uctxt->expected_count / uctxt->subctxt_cnt;
@ -158,18 +142,10 @@ void hfi1_user_exp_rcv_free(struct hfi1_filedata *fd)
{ {
struct hfi1_ctxtdata *uctxt = fd->uctxt; struct hfi1_ctxtdata *uctxt = fd->uctxt;
/*
* The notifier would have been removed when the process'es mm
* was freed.
*/
if (fd->handler) {
hfi1_mmu_rb_unregister(fd->handler);
} else {
if (!EXP_TID_SET_EMPTY(uctxt->tid_full_list)) if (!EXP_TID_SET_EMPTY(uctxt->tid_full_list))
unlock_exp_tids(uctxt, &uctxt->tid_full_list, fd); unlock_exp_tids(uctxt, &uctxt->tid_full_list, fd);
if (!EXP_TID_SET_EMPTY(uctxt->tid_used_list)) if (!EXP_TID_SET_EMPTY(uctxt->tid_used_list))
unlock_exp_tids(uctxt, &uctxt->tid_used_list, fd); unlock_exp_tids(uctxt, &uctxt->tid_used_list, fd);
}
kfree(fd->invalid_tids); kfree(fd->invalid_tids);
fd->invalid_tids = NULL; fd->invalid_tids = NULL;
@ -201,7 +177,7 @@ static void unpin_rcv_pages(struct hfi1_filedata *fd,
if (mapped) { if (mapped) {
pci_unmap_single(dd->pcidev, node->dma_addr, pci_unmap_single(dd->pcidev, node->dma_addr,
node->mmu.len, PCI_DMA_FROMDEVICE); node->npages * PAGE_SIZE, PCI_DMA_FROMDEVICE);
pages = &node->pages[idx]; pages = &node->pages[idx];
} else { } else {
pages = &tidbuf->pages[idx]; pages = &tidbuf->pages[idx];
@ -777,8 +753,7 @@ static int set_rcvarray_entry(struct hfi1_filedata *fd,
return -EFAULT; return -EFAULT;
} }
node->mmu.addr = tbuf->vaddr + (pageidx * PAGE_SIZE); node->fdata = fd;
node->mmu.len = npages * PAGE_SIZE;
node->phys = page_to_phys(pages[0]); node->phys = page_to_phys(pages[0]);
node->npages = npages; node->npages = npages;
node->rcventry = rcventry; node->rcventry = rcventry;
@ -787,23 +762,35 @@ static int set_rcvarray_entry(struct hfi1_filedata *fd,
node->freed = false; node->freed = false;
memcpy(node->pages, pages, sizeof(struct page *) * npages); memcpy(node->pages, pages, sizeof(struct page *) * npages);
if (!fd->handler) if (fd->use_mn) {
ret = tid_rb_insert(fd, &node->mmu); ret = mmu_interval_notifier_insert(
else &node->notifier, fd->mm,
ret = hfi1_mmu_rb_insert(fd->handler, &node->mmu); tbuf->vaddr + (pageidx * PAGE_SIZE), npages * PAGE_SIZE,
&tid_mn_ops);
if (ret)
goto out_unmap;
/*
* FIXME: This is in the wrong order, the notifier should be
* established before the pages are pinned by pin_rcv_pages.
*/
mmu_interval_read_begin(&node->notifier);
}
fd->entry_to_rb[node->rcventry - uctxt->expected_base] = node;
if (ret) { hfi1_put_tid(dd, rcventry, PT_EXPECTED, phys, ilog2(npages) + 1);
trace_hfi1_exp_tid_reg(uctxt->ctxt, fd->subctxt, rcventry, npages,
node->notifier.interval_tree.start, node->phys,
phys);
return 0;
out_unmap:
hfi1_cdbg(TID, "Failed to insert RB node %u 0x%lx, 0x%lx %d", hfi1_cdbg(TID, "Failed to insert RB node %u 0x%lx, 0x%lx %d",
node->rcventry, node->mmu.addr, node->phys, ret); node->rcventry, node->notifier.interval_tree.start,
node->phys, ret);
pci_unmap_single(dd->pcidev, phys, npages * PAGE_SIZE, pci_unmap_single(dd->pcidev, phys, npages * PAGE_SIZE,
PCI_DMA_FROMDEVICE); PCI_DMA_FROMDEVICE);
kfree(node); kfree(node);
return -EFAULT; return -EFAULT;
}
hfi1_put_tid(dd, rcventry, PT_EXPECTED, phys, ilog2(npages) + 1);
trace_hfi1_exp_tid_reg(uctxt->ctxt, fd->subctxt, rcventry, npages,
node->mmu.addr, node->phys, phys);
return 0;
} }
static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo, static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
@ -833,10 +820,9 @@ static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
if (grp) if (grp)
*grp = node->grp; *grp = node->grp;
if (!fd->handler) if (fd->use_mn)
mmu_interval_notifier_remove(&node->notifier);
cacheless_tid_rb_remove(fd, node); cacheless_tid_rb_remove(fd, node);
else
hfi1_mmu_rb_remove(fd->handler, &node->mmu);
return 0; return 0;
} }
@ -847,7 +833,8 @@ static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node)
struct hfi1_devdata *dd = uctxt->dd; struct hfi1_devdata *dd = uctxt->dd;
trace_hfi1_exp_tid_unreg(uctxt->ctxt, fd->subctxt, node->rcventry, trace_hfi1_exp_tid_unreg(uctxt->ctxt, fd->subctxt, node->rcventry,
node->npages, node->mmu.addr, node->phys, node->npages,
node->notifier.interval_tree.start, node->phys,
node->dma_addr); node->dma_addr);
/* /*
@ -894,30 +881,29 @@ static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt,
if (!node || node->rcventry != rcventry) if (!node || node->rcventry != rcventry)
continue; continue;
if (fd->use_mn)
mmu_interval_notifier_remove(
&node->notifier);
cacheless_tid_rb_remove(fd, node); cacheless_tid_rb_remove(fd, node);
} }
} }
} }
} }
/* static bool tid_rb_invalidate(struct mmu_interval_notifier *mni,
* Always return 0 from this function. A non-zero return indicates that the const struct mmu_notifier_range *range,
* remove operation will be called and that memory should be unpinned. unsigned long cur_seq)
* However, the driver cannot unpin out from under PSM. Instead, retain the
* memory (by returning 0) and inform PSM that the memory is going away. PSM
* will call back later when it has removed the memory from its list.
*/
static int tid_rb_invalidate(void *arg, struct mmu_rb_node *mnode)
{ {
struct hfi1_filedata *fdata = arg;
struct hfi1_ctxtdata *uctxt = fdata->uctxt;
struct tid_rb_node *node = struct tid_rb_node *node =
container_of(mnode, struct tid_rb_node, mmu); container_of(mni, struct tid_rb_node, notifier);
struct hfi1_filedata *fdata = node->fdata;
struct hfi1_ctxtdata *uctxt = fdata->uctxt;
if (node->freed) if (node->freed)
return 0; return true;
trace_hfi1_exp_tid_inval(uctxt->ctxt, fdata->subctxt, node->mmu.addr, trace_hfi1_exp_tid_inval(uctxt->ctxt, fdata->subctxt,
node->notifier.interval_tree.start,
node->rcventry, node->npages, node->dma_addr); node->rcventry, node->npages, node->dma_addr);
node->freed = true; node->freed = true;
@ -946,18 +932,7 @@ static int tid_rb_invalidate(void *arg, struct mmu_rb_node *mnode)
fdata->invalid_tid_idx++; fdata->invalid_tid_idx++;
} }
spin_unlock(&fdata->invalid_lock); spin_unlock(&fdata->invalid_lock);
return 0; return true;
}
static int tid_rb_insert(void *arg, struct mmu_rb_node *node)
{
struct hfi1_filedata *fdata = arg;
struct tid_rb_node *tnode =
container_of(node, struct tid_rb_node, mmu);
u32 base = fdata->uctxt->expected_base;
fdata->entry_to_rb[tnode->rcventry - base] = tnode;
return 0;
} }
static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata, static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
@ -968,12 +943,3 @@ static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
fdata->entry_to_rb[tnode->rcventry - base] = NULL; fdata->entry_to_rb[tnode->rcventry - base] = NULL;
clear_tid_node(fdata, tnode); clear_tid_node(fdata, tnode);
} }
static void tid_rb_remove(void *arg, struct mmu_rb_node *node)
{
struct hfi1_filedata *fdata = arg;
struct tid_rb_node *tnode =
container_of(node, struct tid_rb_node, mmu);
cacheless_tid_rb_remove(fdata, tnode);
}

3
drivers/infiniband/hw/hfi1/user_exp_rcv.h
View File

@ -65,7 +65,8 @@ struct tid_user_buf {
}; };
struct tid_rb_node { struct tid_rb_node {
struct mmu_rb_node mmu; struct mmu_interval_notifier notifier;
struct hfi1_filedata *fdata;
unsigned long phys; unsigned long phys;
struct tid_group *grp; struct tid_group *grp;
u32 rcventry; u32 rcventry;

7
drivers/infiniband/hw/mlx5/mlx5_ib.h
View File

@ -1258,8 +1258,6 @@ int mlx5_ib_odp_init_one(struct mlx5_ib_dev *ibdev);
void mlx5_ib_odp_cleanup_one(struct mlx5_ib_dev *ibdev); void mlx5_ib_odp_cleanup_one(struct mlx5_ib_dev *ibdev);
int __init mlx5_ib_odp_init(void); int __init mlx5_ib_odp_init(void);
void mlx5_ib_odp_cleanup(void); void mlx5_ib_odp_cleanup(void);
void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp, unsigned long start,
unsigned long end);
void mlx5_odp_init_mr_cache_entry(struct mlx5_cache_ent *ent); void mlx5_odp_init_mr_cache_entry(struct mlx5_cache_ent *ent);
void mlx5_odp_populate_klm(struct mlx5_klm *pklm, size_t offset, void mlx5_odp_populate_klm(struct mlx5_klm *pklm, size_t offset,
size_t nentries, struct mlx5_ib_mr *mr, int flags); size_t nentries, struct mlx5_ib_mr *mr, int flags);
@ -1289,11 +1287,10 @@ mlx5_ib_advise_mr_prefetch(struct ib_pd *pd,
{ {
return -EOPNOTSUPP; return -EOPNOTSUPP;
} }
static inline void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp,
unsigned long start,
unsigned long end){};
#endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
extern const struct mmu_interval_notifier_ops mlx5_mn_ops;
/* Needed for rep profile */ /* Needed for rep profile */
void __mlx5_ib_remove(struct mlx5_ib_dev *dev, void __mlx5_ib_remove(struct mlx5_ib_dev *dev,
const struct mlx5_ib_profile *profile, const struct mlx5_ib_profile *profile,

3
drivers/infiniband/hw/mlx5/mr.c
View File

@ -749,7 +749,8 @@ static int mr_umem_get(struct mlx5_ib_dev *dev, struct ib_udata *udata,
if (access_flags & IB_ACCESS_ON_DEMAND) { if (access_flags & IB_ACCESS_ON_DEMAND) {
struct ib_umem_odp *odp; struct ib_umem_odp *odp;
odp = ib_umem_odp_get(udata, start, length, access_flags); odp = ib_umem_odp_get(udata, start, length, access_flags,
&mlx5_mn_ops);
if (IS_ERR(odp)) { if (IS_ERR(odp)) {
mlx5_ib_dbg(dev, "umem get failed (%ld)\n", mlx5_ib_dbg(dev, "umem get failed (%ld)\n",
PTR_ERR(odp)); PTR_ERR(odp));

50
drivers/infiniband/hw/mlx5/odp.c
View File

@ -241,18 +241,27 @@ out_unlock:
xa_unlock(&imr->implicit_children); xa_unlock(&imr->implicit_children);
} }
void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp, unsigned long start, static bool mlx5_ib_invalidate_range(struct mmu_interval_notifier *mni,
unsigned long end) const struct mmu_notifier_range *range,
unsigned long cur_seq)
{ {
struct ib_umem_odp *umem_odp =
container_of(mni, struct ib_umem_odp, notifier);
struct mlx5_ib_mr *mr; struct mlx5_ib_mr *mr;
const u64 umr_block_mask = (MLX5_UMR_MTT_ALIGNMENT / const u64 umr_block_mask = (MLX5_UMR_MTT_ALIGNMENT /
sizeof(struct mlx5_mtt)) - 1; sizeof(struct mlx5_mtt)) - 1;
u64 idx = 0, blk_start_idx = 0; u64 idx = 0, blk_start_idx = 0;
u64 invalidations = 0; u64 invalidations = 0;
unsigned long start;
unsigned long end;
int in_block = 0; int in_block = 0;
u64 addr; u64 addr;
if (!mmu_notifier_range_blockable(range))
return false;
mutex_lock(&umem_odp->umem_mutex); mutex_lock(&umem_odp->umem_mutex);
mmu_interval_set_seq(mni, cur_seq);
/* /*
* If npages is zero then umem_odp->private may not be setup yet. This * If npages is zero then umem_odp->private may not be setup yet. This
* does not complete until after the first page is mapped for DMA. * does not complete until after the first page is mapped for DMA.
@ -261,8 +270,8 @@ void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp, unsigned long start,
goto out; goto out;
mr = umem_odp->private; mr = umem_odp->private;
start = max_t(u64, ib_umem_start(umem_odp), start); start = max_t(u64, ib_umem_start(umem_odp), range->start);
end = min_t(u64, ib_umem_end(umem_odp), end); end = min_t(u64, ib_umem_end(umem_odp), range->end);
/* /*
* Iteration one - zap the HW's MTTs. The notifiers_count ensures that * Iteration one - zap the HW's MTTs. The notifiers_count ensures that
@ -319,8 +328,13 @@ void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp, unsigned long start,
destroy_unused_implicit_child_mr(mr); destroy_unused_implicit_child_mr(mr);
out: out:
mutex_unlock(&umem_odp->umem_mutex); mutex_unlock(&umem_odp->umem_mutex);
return true;
} }
const struct mmu_interval_notifier_ops mlx5_mn_ops = {
.invalidate = mlx5_ib_invalidate_range,
};
void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev) void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev)
{ {
struct ib_odp_caps *caps = &dev->odp_caps; struct ib_odp_caps *caps = &dev->odp_caps;
@ -419,7 +433,7 @@ static struct mlx5_ib_mr *implicit_get_child_mr(struct mlx5_ib_mr *imr,
odp = ib_umem_odp_alloc_child(to_ib_umem_odp(imr->umem), odp = ib_umem_odp_alloc_child(to_ib_umem_odp(imr->umem),
idx * MLX5_IMR_MTT_SIZE, idx * MLX5_IMR_MTT_SIZE,
MLX5_IMR_MTT_SIZE); MLX5_IMR_MTT_SIZE, &mlx5_mn_ops);
if (IS_ERR(odp)) if (IS_ERR(odp))
return ERR_CAST(odp); return ERR_CAST(odp);
@ -606,8 +620,9 @@ static int pagefault_real_mr(struct mlx5_ib_mr *mr, struct ib_umem_odp *odp,
u64 user_va, size_t bcnt, u32 *bytes_mapped, u64 user_va, size_t bcnt, u32 *bytes_mapped,
u32 flags) u32 flags)
{ {
int current_seq, page_shift, ret, np; int page_shift, ret, np;
bool downgrade = flags & MLX5_PF_FLAGS_DOWNGRADE; bool downgrade = flags & MLX5_PF_FLAGS_DOWNGRADE;
unsigned long current_seq;
u64 access_mask; u64 access_mask;
u64 start_idx, page_mask; u64 start_idx, page_mask;
@ -619,12 +634,7 @@ static int pagefault_real_mr(struct mlx5_ib_mr *mr, struct ib_umem_odp *odp,
if (odp->umem.writable && !downgrade) if (odp->umem.writable && !downgrade)
access_mask |= ODP_WRITE_ALLOWED_BIT; access_mask |= ODP_WRITE_ALLOWED_BIT;
current_seq = READ_ONCE(odp->notifiers_seq); current_seq = mmu_interval_read_begin(&odp->notifier);
/*
* Ensure the sequence number is valid for some time before we call
* gup.
*/
smp_rmb();
np = ib_umem_odp_map_dma_pages(odp, user_va, bcnt, access_mask, np = ib_umem_odp_map_dma_pages(odp, user_va, bcnt, access_mask,
current_seq); current_seq);
@ -632,7 +642,7 @@ static int pagefault_real_mr(struct mlx5_ib_mr *mr, struct ib_umem_odp *odp,
return np; return np;
mutex_lock(&odp->umem_mutex); mutex_lock(&odp->umem_mutex);
if (!ib_umem_mmu_notifier_retry(odp, current_seq)) { if (!mmu_interval_read_retry(&odp->notifier, current_seq)) {
/* /*
* No need to check whether the MTTs really belong to * No need to check whether the MTTs really belong to
* this MR, since ib_umem_odp_map_dma_pages already * this MR, since ib_umem_odp_map_dma_pages already
@ -662,19 +672,6 @@ static int pagefault_real_mr(struct mlx5_ib_mr *mr, struct ib_umem_odp *odp,
return np << (page_shift - PAGE_SHIFT); return np << (page_shift - PAGE_SHIFT);
out: out:
if (ret == -EAGAIN) {
unsigned long timeout = msecs_to_jiffies(MMU_NOTIFIER_TIMEOUT);
if (!wait_for_completion_timeout(&odp->notifier_completion,
timeout)) {
mlx5_ib_warn(
mr->dev,
"timeout waiting for mmu notifier. seq %d against %d. notifiers_count=%d\n",
current_seq, odp->notifiers_seq,
odp->notifiers_count);
}
}
return ret; return ret;
} }
@ -1622,7 +1619,6 @@ void mlx5_odp_init_mr_cache_entry(struct mlx5_cache_ent *ent)
static const struct ib_device_ops mlx5_ib_dev_odp_ops = { static const struct ib_device_ops mlx5_ib_dev_odp_ops = {
.advise_mr = mlx5_ib_advise_mr, .advise_mr = mlx5_ib_advise_mr,
.invalidate_range = mlx5_ib_invalidate_range,
}; };
int mlx5_ib_odp_init_one(struct mlx5_ib_dev *dev) int mlx5_ib_odp_init_one(struct mlx5_ib_dev *dev)

8
drivers/xen/gntdev-common.h
View File

@ -21,15 +21,8 @@ struct gntdev_dmabuf_priv;
struct gntdev_priv { struct gntdev_priv {
/* Maps with visible offsets in the file descriptor. */ /* Maps with visible offsets in the file descriptor. */
struct list_head maps; struct list_head maps;
/*
* Maps that are not visible; will be freed on munmap.
* Only populated if populate_freeable_maps == 1
*/
struct list_head freeable_maps;
/* lock protects maps and freeable_maps. */ /* lock protects maps and freeable_maps. */
struct mutex lock; struct mutex lock;
struct mm_struct *mm;
struct mmu_notifier mn;
#ifdef CONFIG_XEN_GRANT_DMA_ALLOC #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
/* Device for which DMA memory is allocated. */ /* Device for which DMA memory is allocated. */
@ -49,6 +42,7 @@ struct gntdev_unmap_notify {
}; };
struct gntdev_grant_map { struct gntdev_grant_map {
struct mmu_interval_notifier notifier;
struct list_head next; struct list_head next;
struct vm_area_struct *vma; struct vm_area_struct *vma;
int index; int index;

179
drivers/xen/gntdev.c
View File

@ -63,7 +63,6 @@ MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by "
static atomic_t pages_mapped = ATOMIC_INIT(0); static atomic_t pages_mapped = ATOMIC_INIT(0);
static int use_ptemod; static int use_ptemod;
#define populate_freeable_maps use_ptemod
static int unmap_grant_pages(struct gntdev_grant_map *map, static int unmap_grant_pages(struct gntdev_grant_map *map,
int offset, int pages); int offset, int pages);
@ -249,12 +248,6 @@ void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map)
evtchn_put(map->notify.event); evtchn_put(map->notify.event);
} }
if (populate_freeable_maps && priv) {
mutex_lock(&priv->lock);
list_del(&map->next);
mutex_unlock(&priv->lock);
}
if (map->pages && !use_ptemod) if (map->pages && !use_ptemod)
unmap_grant_pages(map, 0, map->count); unmap_grant_pages(map, 0, map->count);
gntdev_free_map(map); gntdev_free_map(map);
@ -444,16 +437,9 @@ static void gntdev_vma_close(struct vm_area_struct *vma)
pr_debug("gntdev_vma_close %p\n", vma); pr_debug("gntdev_vma_close %p\n", vma);
if (use_ptemod) { if (use_ptemod) {
/* It is possible that an mmu notifier could be running WARN_ON(map->vma != vma);
* concurrently, so take priv->lock to ensure that the vma won't mmu_interval_notifier_remove(&map->notifier);
* vanishing during the unmap_grant_pages call, since we will
* spin here until that completes. Such a concurrent call will
* not do any unmapping, since that has been done prior to
* closing the vma, but it may still iterate the unmap_ops list.
*/
mutex_lock(&priv->lock);
map->vma = NULL; map->vma = NULL;
mutex_unlock(&priv->lock);
} }
vma->vm_private_data = NULL; vma->vm_private_data = NULL;
gntdev_put_map(priv, map); gntdev_put_map(priv, map);
@ -475,109 +461,44 @@ static const struct vm_operations_struct gntdev_vmops = {
/* ------------------------------------------------------------------ */ /* ------------------------------------------------------------------ */
static bool in_range(struct gntdev_grant_map *map, static bool gntdev_invalidate(struct mmu_interval_notifier *mn,
unsigned long start, unsigned long end) const struct mmu_notifier_range *range,
{ unsigned long cur_seq)
if (!map->vma)
return false;
if (map->vma->vm_start >= end)
return false;
if (map->vma->vm_end <= start)
return false;
return true;
}
static int unmap_if_in_range(struct gntdev_grant_map *map,
unsigned long start, unsigned long end,
bool blockable)
{ {
struct gntdev_grant_map *map =
container_of(mn, struct gntdev_grant_map, notifier);
unsigned long mstart, mend; unsigned long mstart, mend;
int err; int err;
if (!in_range(map, start, end)) if (!mmu_notifier_range_blockable(range))
return 0; return false;
if (!blockable) /*
return -EAGAIN; * If the VMA is split or otherwise changed the notifier is not
* updated, but we don't want to process VA's outside the modified
* VMA. FIXME: It would be much more understandable to just prevent
* modifying the VMA in the first place.
*/
if (map->vma->vm_start >= range->end ||
map->vma->vm_end <= range->start)
return true;
mstart = max(start, map->vma->vm_start); mstart = max(range->start, map->vma->vm_start);
mend = min(end, map->vma->vm_end); mend = min(range->end, map->vma->vm_end);
pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n",
map->index, map->count, map->index, map->count,
map->vma->vm_start, map->vma->vm_end, map->vma->vm_start, map->vma->vm_end,
start, end, mstart, mend); range->start, range->end, mstart, mend);
err = unmap_grant_pages(map, err = unmap_grant_pages(map,
(mstart - map->vma->vm_start) >> PAGE_SHIFT, (mstart - map->vma->vm_start) >> PAGE_SHIFT,
(mend - mstart) >> PAGE_SHIFT); (mend - mstart) >> PAGE_SHIFT);
WARN_ON(err); WARN_ON(err);
return 0; return true;
} }
static int mn_invl_range_start(struct mmu_notifier *mn, static const struct mmu_interval_notifier_ops gntdev_mmu_ops = {
const struct mmu_notifier_range *range) .invalidate = gntdev_invalidate,
{
struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
struct gntdev_grant_map *map;
int ret = 0;
if (mmu_notifier_range_blockable(range))
mutex_lock(&priv->lock);
else if (!mutex_trylock(&priv->lock))
return -EAGAIN;
list_for_each_entry(map, &priv->maps, next) {
ret = unmap_if_in_range(map, range->start, range->end,
mmu_notifier_range_blockable(range));
if (ret)
goto out_unlock;
}
list_for_each_entry(map, &priv->freeable_maps, next) {
ret = unmap_if_in_range(map, range->start, range->end,
mmu_notifier_range_blockable(range));
if (ret)
goto out_unlock;
}
out_unlock:
mutex_unlock(&priv->lock);
return ret;
}
static void mn_release(struct mmu_notifier *mn,
struct mm_struct *mm)
{
struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
struct gntdev_grant_map *map;
int err;
mutex_lock(&priv->lock);
list_for_each_entry(map, &priv->maps, next) {
if (!map->vma)
continue;
pr_debug("map %d+%d (%lx %lx)\n",
map->index, map->count,
map->vma->vm_start, map->vma->vm_end);
err = unmap_grant_pages(map, /* offset */ 0, map->count);
WARN_ON(err);
}
list_for_each_entry(map, &priv->freeable_maps, next) {
if (!map->vma)
continue;
pr_debug("map %d+%d (%lx %lx)\n",
map->index, map->count,
map->vma->vm_start, map->vma->vm_end);
err = unmap_grant_pages(map, /* offset */ 0, map->count);
WARN_ON(err);
}
mutex_unlock(&priv->lock);
}
static const struct mmu_notifier_ops gntdev_mmu_ops = {
.release = mn_release,
.invalidate_range_start = mn_invl_range_start,
}; };
/* ------------------------------------------------------------------ */ /* ------------------------------------------------------------------ */
@ -592,7 +513,6 @@ static int gntdev_open(struct inode *inode, struct file *flip)
return -ENOMEM; return -ENOMEM;
INIT_LIST_HEAD(&priv->maps); INIT_LIST_HEAD(&priv->maps);
INIT_LIST_HEAD(&priv->freeable_maps);
mutex_init(&priv->lock); mutex_init(&priv->lock);
#ifdef CONFIG_XEN_GNTDEV_DMABUF #ifdef CONFIG_XEN_GNTDEV_DMABUF
@ -604,17 +524,6 @@ static int gntdev_open(struct inode *inode, struct file *flip)
} }
#endif #endif
if (use_ptemod) {
priv->mm = get_task_mm(current);
if (!priv->mm) {
kfree(priv);
return -ENOMEM;
}
priv->mn.ops = &gntdev_mmu_ops;
ret = mmu_notifier_register(&priv->mn, priv->mm);
mmput(priv->mm);
}
if (ret) { if (ret) {
kfree(priv); kfree(priv);
return ret; return ret;
@ -644,16 +553,12 @@ static int gntdev_release(struct inode *inode, struct file *flip)
list_del(&map->next); list_del(&map->next);
gntdev_put_map(NULL /* already removed */, map); gntdev_put_map(NULL /* already removed */, map);
} }
WARN_ON(!list_empty(&priv->freeable_maps));
mutex_unlock(&priv->lock); mutex_unlock(&priv->lock);
#ifdef CONFIG_XEN_GNTDEV_DMABUF #ifdef CONFIG_XEN_GNTDEV_DMABUF
gntdev_dmabuf_fini(priv->dmabuf_priv); gntdev_dmabuf_fini(priv->dmabuf_priv);
#endif #endif
if (use_ptemod)
mmu_notifier_unregister(&priv->mn, priv->mm);
kfree(priv); kfree(priv);
return 0; return 0;
} }
@ -714,8 +619,6 @@ static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count);
if (map) { if (map) {
list_del(&map->next); list_del(&map->next);
if (populate_freeable_maps)
list_add_tail(&map->next, &priv->freeable_maps);
err = 0; err = 0;
} }
mutex_unlock(&priv->lock); mutex_unlock(&priv->lock);
@ -1087,11 +990,6 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
goto unlock_out; goto unlock_out;
if (use_ptemod && map->vma) if (use_ptemod && map->vma)
goto unlock_out; goto unlock_out;
if (use_ptemod && priv->mm != vma->vm_mm) {
pr_warn("Huh? Other mm?\n");
goto unlock_out;
}
refcount_inc(&map->users); refcount_inc(&map->users);
vma->vm_ops = &gntdev_vmops; vma->vm_ops = &gntdev_vmops;
@ -1102,10 +1000,6 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
vma->vm_flags |= VM_DONTCOPY; vma->vm_flags |= VM_DONTCOPY;
vma->vm_private_data = map; vma->vm_private_data = map;
if (use_ptemod)
map->vma = vma;
if (map->flags) { if (map->flags) {
if ((vma->vm_flags & VM_WRITE) && if ((vma->vm_flags & VM_WRITE) &&
(map->flags & GNTMAP_readonly)) (map->flags & GNTMAP_readonly))
@ -1116,8 +1010,28 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
map->flags |= GNTMAP_readonly; map->flags |= GNTMAP_readonly;
} }
if (use_ptemod) {
map->vma = vma;
err = mmu_interval_notifier_insert_locked(
&map->notifier, vma->vm_mm, vma->vm_start,
vma->vm_end - vma->vm_start, &gntdev_mmu_ops);
if (err)
goto out_unlock_put;
}
mutex_unlock(&priv->lock); mutex_unlock(&priv->lock);
/*
* gntdev takes the address of the PTE in find_grant_ptes() and passes
* it to the hypervisor in gntdev_map_grant_pages(). The purpose of
* the notifier is to prevent the hypervisor pointer to the PTE from
* going stale.
*
* Since this vma's mappings can't be touched without the mmap_sem,
* and we are holding it now, there is no need for the notifier_range
* locking pattern.
*/
mmu_interval_read_begin(&map->notifier);
if (use_ptemod) { if (use_ptemod) {
map->pages_vm_start = vma->vm_start; map->pages_vm_start = vma->vm_start;
err = apply_to_page_range(vma->vm_mm, vma->vm_start, err = apply_to_page_range(vma->vm_mm, vma->vm_start,
@ -1166,8 +1080,11 @@ out_unlock_put:
mutex_unlock(&priv->lock); mutex_unlock(&priv->lock);
out_put_map: out_put_map:
if (use_ptemod) { if (use_ptemod) {
map->vma = NULL;
unmap_grant_pages(map, 0, map->count); unmap_grant_pages(map, 0, map->count);
if (map->vma) {
mmu_interval_notifier_remove(&map->notifier);
map->vma = NULL;
}
} }
gntdev_put_map(priv, map); gntdev_put_map(priv, map);
return err; return err;

190
include/linux/hmm.h
View File

@ -62,37 +62,12 @@
#include <linux/kconfig.h> #include <linux/kconfig.h>
#include <asm/pgtable.h> #include <asm/pgtable.h>
#ifdef CONFIG_HMM_MIRROR
#include <linux/device.h> #include <linux/device.h>
#include <linux/migrate.h> #include <linux/migrate.h>
#include <linux/memremap.h> #include <linux/memremap.h>
#include <linux/completion.h> #include <linux/completion.h>
#include <linux/mmu_notifier.h> #include <linux/mmu_notifier.h>
/*
* struct hmm - HMM per mm struct
*
* @mm: mm struct this HMM struct is bound to
* @lock: lock protecting ranges list
* @ranges: list of range being snapshotted
* @mirrors: list of mirrors for this mm
* @mmu_notifier: mmu notifier to track updates to CPU page table
* @mirrors_sem: read/write semaphore protecting the mirrors list
* @wq: wait queue for user waiting on a range invalidation
* @notifiers: count of active mmu notifiers
*/
struct hmm {
struct mmu_notifier mmu_notifier;
spinlock_t ranges_lock;
struct list_head ranges;
struct list_head mirrors;
struct rw_semaphore mirrors_sem;
wait_queue_head_t wq;
long notifiers;
};
/* /*
* hmm_pfn_flag_e - HMM flag enums * hmm_pfn_flag_e - HMM flag enums
* *
@ -145,6 +120,8 @@ enum hmm_pfn_value_e {
/* /*
* struct hmm_range - track invalidation lock on virtual address range * struct hmm_range - track invalidation lock on virtual address range
* *
* @notifier: a mmu_interval_notifier that includes the start/end
* @notifier_seq: result of mmu_interval_read_begin()
* @hmm: the core HMM structure this range is active against * @hmm: the core HMM structure this range is active against
* @vma: the vm area struct for the range * @vma: the vm area struct for the range
* @list: all range lock are on a list * @list: all range lock are on a list
@ -159,8 +136,8 @@ enum hmm_pfn_value_e {
* @valid: pfns array did not change since it has been fill by an HMM function * @valid: pfns array did not change since it has been fill by an HMM function
*/ */
struct hmm_range { struct hmm_range {
struct hmm *hmm; struct mmu_interval_notifier *notifier;
struct list_head list; unsigned long notifier_seq;
unsigned long start; unsigned long start;
unsigned long end; unsigned long end;
uint64_t *pfns; uint64_t *pfns;
@ -169,32 +146,8 @@ struct hmm_range {
uint64_t default_flags; uint64_t default_flags;
uint64_t pfn_flags_mask; uint64_t pfn_flags_mask;
uint8_t pfn_shift; uint8_t pfn_shift;
bool valid;
}; };
/*
* hmm_range_wait_until_valid() - wait for range to be valid
* @range: range affected by invalidation to wait on
* @timeout: time out for wait in ms (ie abort wait after that period of time)
* Return: true if the range is valid, false otherwise.
*/
static inline bool hmm_range_wait_until_valid(struct hmm_range *range,
unsigned long timeout)
{
return wait_event_timeout(range->hmm->wq, range->valid,
msecs_to_jiffies(timeout)) != 0;
}
/*
* hmm_range_valid() - test if a range is valid or not
* @range: range
* Return: true if the range is valid, false otherwise.
*/
static inline bool hmm_range_valid(struct hmm_range *range)
{
return range->valid;
}
/* /*
* hmm_device_entry_to_page() - return struct page pointed to by a device entry * hmm_device_entry_to_page() - return struct page pointed to by a device entry
* @range: range use to decode device entry value * @range: range use to decode device entry value
@ -264,120 +217,6 @@ static inline uint64_t hmm_device_entry_from_pfn(const struct hmm_range *range,
range->flags[HMM_PFN_VALID]; range->flags[HMM_PFN_VALID];
} }
/*
* Mirroring: how to synchronize device page table with CPU page table.
*
* A device driver that is participating in HMM mirroring must always
* synchronize with CPU page table updates. For this, device drivers can either
* directly use mmu_notifier APIs or they can use the hmm_mirror API. Device
* drivers can decide to register one mirror per device per process, or just
* one mirror per process for a group of devices. The pattern is:
*
* int device_bind_address_space(..., struct mm_struct *mm, ...)
* {
* struct device_address_space *das;
*
* // Device driver specific initialization, and allocation of das
* // which contains an hmm_mirror struct as one of its fields.
* ...
*
* ret = hmm_mirror_register(&das->mirror, mm, &device_mirror_ops);
* if (ret) {
* // Cleanup on error
* return ret;
* }
*
* // Other device driver specific initialization
* ...
* }
*
* Once an hmm_mirror is registered for an address space, the device driver
* will get callbacks through sync_cpu_device_pagetables() operation (see
* hmm_mirror_ops struct).
*
* Device driver must not free the struct containing the hmm_mirror struct
* before calling hmm_mirror_unregister(). The expected usage is to do that when
* the device driver is unbinding from an address space.
*
*
* void device_unbind_address_space(struct device_address_space *das)
* {
* // Device driver specific cleanup
* ...
*
* hmm_mirror_unregister(&das->mirror);
*
* // Other device driver specific cleanup, and now das can be freed
* ...
* }
*/
struct hmm_mirror;
/*
* struct hmm_mirror_ops - HMM mirror device operations callback
*
* @update: callback to update range on a device
*/
struct hmm_mirror_ops {
/* release() - release hmm_mirror
*
* @mirror: pointer to struct hmm_mirror
*
* This is called when the mm_struct is being released. The callback
* must ensure that all access to any pages obtained from this mirror
* is halted before the callback returns. All future access should
* fault.
*/
void (*release)(struct hmm_mirror *mirror);
/* sync_cpu_device_pagetables() - synchronize page tables
*
* @mirror: pointer to struct hmm_mirror
* @update: update information (see struct mmu_notifier_range)
* Return: -EAGAIN if mmu_notifier_range_blockable(update) is false
* and callback needs to block, 0 otherwise.
*
* This callback ultimately originates from mmu_notifiers when the CPU
* page table is updated. The device driver must update its page table
* in response to this callback. The update argument tells what action
* to perform.
*
* The device driver must not return from this callback until the device
* page tables are completely updated (TLBs flushed, etc); this is a
* synchronous call.
*/
int (*sync_cpu_device_pagetables)(
struct hmm_mirror *mirror,
const struct mmu_notifier_range *update);
};
/*
* struct hmm_mirror - mirror struct for a device driver
*
* @hmm: pointer to struct hmm (which is unique per mm_struct)
* @ops: device driver callback for HMM mirror operations
* @list: for list of mirrors of a given mm
*
* Each address space (mm_struct) being mirrored by a device must register one
* instance of an hmm_mirror struct with HMM. HMM will track the list of all
* mirrors for each mm_struct.
*/
struct hmm_mirror {
struct hmm *hmm;
const struct hmm_mirror_ops *ops;
struct list_head list;
};
int hmm_mirror_register(struct hmm_mirror *mirror, struct mm_struct *mm);
void hmm_mirror_unregister(struct hmm_mirror *mirror);
/*
* Please see Documentation/vm/hmm.rst for how to use the range API.
*/
int hmm_range_register(struct hmm_range *range, struct hmm_mirror *mirror);
void hmm_range_unregister(struct hmm_range *range);
/* /*
* Retry fault if non-blocking, drop mmap_sem and return -EAGAIN in that case. * Retry fault if non-blocking, drop mmap_sem and return -EAGAIN in that case.
*/ */
@ -386,16 +225,17 @@ void hmm_range_unregister(struct hmm_range *range);
/* Don't fault in missing PTEs, just snapshot the current state. */ /* Don't fault in missing PTEs, just snapshot the current state. */
#define HMM_FAULT_SNAPSHOT (1 << 1) #define HMM_FAULT_SNAPSHOT (1 << 1)
#ifdef CONFIG_HMM_MIRROR
/*
* Please see Documentation/vm/hmm.rst for how to use the range API.
*/
long hmm_range_fault(struct hmm_range *range, unsigned int flags); long hmm_range_fault(struct hmm_range *range, unsigned int flags);
#else
long hmm_range_dma_map(struct hmm_range *range, static inline long hmm_range_fault(struct hmm_range *range, unsigned int flags)
struct device *device, {
dma_addr_t *daddrs, return -EOPNOTSUPP;
unsigned int flags); }
long hmm_range_dma_unmap(struct hmm_range *range, #endif
struct device *device,
dma_addr_t *daddrs,
bool dirty);
/* /*
* HMM_RANGE_DEFAULT_TIMEOUT - default timeout (ms) when waiting for a range * HMM_RANGE_DEFAULT_TIMEOUT - default timeout (ms) when waiting for a range
@ -406,6 +246,4 @@ long hmm_range_dma_unmap(struct hmm_range *range,
*/ */
#define HMM_RANGE_DEFAULT_TIMEOUT 1000 #define HMM_RANGE_DEFAULT_TIMEOUT 1000
#endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */
#endif /* LINUX_HMM_H */ #endif /* LINUX_HMM_H */

147
include/linux/mmu_notifier.h
View File

@ -6,9 +6,12 @@
#include <linux/spinlock.h> #include <linux/spinlock.h>
#include <linux/mm_types.h> #include <linux/mm_types.h>
#include <linux/srcu.h> #include <linux/srcu.h>
#include <linux/interval_tree.h>
struct mmu_notifier_mm;
struct mmu_notifier; struct mmu_notifier;
struct mmu_notifier_ops; struct mmu_notifier_range;
struct mmu_interval_notifier;
/** /**
* enum mmu_notifier_event - reason for the mmu notifier callback * enum mmu_notifier_event - reason for the mmu notifier callback
@ -31,6 +34,9 @@ struct mmu_notifier_ops;
* access flags). User should soft dirty the page in the end callback to make * access flags). User should soft dirty the page in the end callback to make
* sure that anyone relying on soft dirtyness catch pages that might be written * sure that anyone relying on soft dirtyness catch pages that might be written
* through non CPU mappings. * through non CPU mappings.
*
* @MMU_NOTIFY_RELEASE: used during mmu_interval_notifier invalidate to signal
* that the mm refcount is zero and the range is no longer accessible.
*/ */
enum mmu_notifier_event { enum mmu_notifier_event {
MMU_NOTIFY_UNMAP = 0, MMU_NOTIFY_UNMAP = 0,
@ -38,38 +44,11 @@ enum mmu_notifier_event {
MMU_NOTIFY_PROTECTION_VMA, MMU_NOTIFY_PROTECTION_VMA,
MMU_NOTIFY_PROTECTION_PAGE, MMU_NOTIFY_PROTECTION_PAGE,
MMU_NOTIFY_SOFT_DIRTY, MMU_NOTIFY_SOFT_DIRTY,
}; MMU_NOTIFY_RELEASE,
#ifdef CONFIG_MMU_NOTIFIER
#ifdef CONFIG_LOCKDEP
extern struct lockdep_map __mmu_notifier_invalidate_range_start_map;
#endif
/*
* The mmu notifier_mm structure is allocated and installed in
* mm->mmu_notifier_mm inside the mm_take_all_locks() protected
* critical section and it's released only when mm_count reaches zero
* in mmdrop().
*/
struct mmu_notifier_mm {
/* all mmu notifiers registerd in this mm are queued in this list */
struct hlist_head list;
/* to serialize the list modifications and hlist_unhashed */
spinlock_t lock;
}; };
#define MMU_NOTIFIER_RANGE_BLOCKABLE (1 << 0) #define MMU_NOTIFIER_RANGE_BLOCKABLE (1 << 0)
struct mmu_notifier_range {
struct vm_area_struct *vma;
struct mm_struct *mm;
unsigned long start;
unsigned long end;
unsigned flags;
enum mmu_notifier_event event;
};
struct mmu_notifier_ops { struct mmu_notifier_ops {
/* /*
* Called either by mmu_notifier_unregister or when the mm is * Called either by mmu_notifier_unregister or when the mm is
@ -249,6 +228,41 @@ struct mmu_notifier {
unsigned int users; unsigned int users;
}; };
/**
* struct mmu_interval_notifier_ops
* @invalidate: Upon return the caller must stop using any SPTEs within this
* range. This function can sleep. Return false only if sleeping
* was required but mmu_notifier_range_blockable(range) is false.
*/
struct mmu_interval_notifier_ops {
bool (*invalidate)(struct mmu_interval_notifier *mni,
const struct mmu_notifier_range *range,
unsigned long cur_seq);
};
struct mmu_interval_notifier {
struct interval_tree_node interval_tree;
const struct mmu_interval_notifier_ops *ops;
struct mm_struct *mm;
struct hlist_node deferred_item;
unsigned long invalidate_seq;
};
#ifdef CONFIG_MMU_NOTIFIER
#ifdef CONFIG_LOCKDEP
extern struct lockdep_map __mmu_notifier_invalidate_range_start_map;
#endif
struct mmu_notifier_range {
struct vm_area_struct *vma;
struct mm_struct *mm;
unsigned long start;
unsigned long end;
unsigned flags;
enum mmu_notifier_event event;
};
static inline int mm_has_notifiers(struct mm_struct *mm) static inline int mm_has_notifiers(struct mm_struct *mm)
{ {
return unlikely(mm->mmu_notifier_mm); return unlikely(mm->mmu_notifier_mm);
@ -275,6 +289,81 @@ extern int __mmu_notifier_register(struct mmu_notifier *mn,
struct mm_struct *mm); struct mm_struct *mm);
extern void mmu_notifier_unregister(struct mmu_notifier *mn, extern void mmu_notifier_unregister(struct mmu_notifier *mn,
struct mm_struct *mm); struct mm_struct *mm);
unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni);
int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
struct mm_struct *mm, unsigned long start,
unsigned long length,
const struct mmu_interval_notifier_ops *ops);
int mmu_interval_notifier_insert_locked(
struct mmu_interval_notifier *mni, struct mm_struct *mm,
unsigned long start, unsigned long length,
const struct mmu_interval_notifier_ops *ops);
void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni);
/**
* mmu_interval_set_seq - Save the invalidation sequence
* @mni - The mni passed to invalidate
* @cur_seq - The cur_seq passed to the invalidate() callback
*
* This must be called unconditionally from the invalidate callback of a
* struct mmu_interval_notifier_ops under the same lock that is used to call
* mmu_interval_read_retry(). It updates the sequence number for later use by
* mmu_interval_read_retry(). The provided cur_seq will always be odd.
*
* If the caller does not call mmu_interval_read_begin() or
* mmu_interval_read_retry() then this call is not required.
*/
static inline void mmu_interval_set_seq(struct mmu_interval_notifier *mni,
unsigned long cur_seq)
{
WRITE_ONCE(mni->invalidate_seq, cur_seq);
}
/**
* mmu_interval_read_retry - End a read side critical section against a VA range
* mni: The range
* seq: The return of the paired mmu_interval_read_begin()
*
* This MUST be called under a user provided lock that is also held
* unconditionally by op->invalidate() when it calls mmu_interval_set_seq().
*
* Each call should be paired with a single mmu_interval_read_begin() and
* should be used to conclude the read side.
*
* Returns true if an invalidation collided with this critical section, and
* the caller should retry.
*/
static inline bool mmu_interval_read_retry(struct mmu_interval_notifier *mni,
unsigned long seq)
{
return mni->invalidate_seq != seq;
}
/**
* mmu_interval_check_retry - Test if a collision has occurred
* mni: The range
* seq: The return of the matching mmu_interval_read_begin()
*
* This can be used in the critical section between mmu_interval_read_begin()
* and mmu_interval_read_retry(). A return of true indicates an invalidation
* has collided with this critical region and a future
* mmu_interval_read_retry() will return true.
*
* False is not reliable and only suggests a collision may not have
* occured. It can be called many times and does not have to hold the user
* provided lock.
*
* This call can be used as part of loops and other expensive operations to
* expedite a retry.
*/
static inline bool mmu_interval_check_retry(struct mmu_interval_notifier *mni,
unsigned long seq)
{
/* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */
return READ_ONCE(mni->invalidate_seq) != seq;
}
extern void __mmu_notifier_mm_destroy(struct mm_struct *mm); extern void __mmu_notifier_mm_destroy(struct mm_struct *mm);
extern void __mmu_notifier_release(struct mm_struct *mm); extern void __mmu_notifier_release(struct mm_struct *mm);
extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm, extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,

68
include/rdma/ib_umem_odp.h
View File

@ -35,11 +35,11 @@
#include <rdma/ib_umem.h> #include <rdma/ib_umem.h>
#include <rdma/ib_verbs.h> #include <rdma/ib_verbs.h>
#include <linux/interval_tree.h>
struct ib_umem_odp { struct ib_umem_odp {
struct ib_umem umem; struct ib_umem umem;
struct ib_ucontext_per_mm *per_mm; struct mmu_interval_notifier notifier;
struct pid *tgid;
/* /*
* An array of the pages included in the on-demand paging umem. * An array of the pages included in the on-demand paging umem.
@ -62,13 +62,8 @@ struct ib_umem_odp {
struct mutex umem_mutex; struct mutex umem_mutex;
void *private; /* for the HW driver to use. */ void *private; /* for the HW driver to use. */
int notifiers_seq;
int notifiers_count;
int npages; int npages;
/* Tree tracking */
struct interval_tree_node interval_tree;
/* /*
* An implicit odp umem cannot be DMA mapped, has 0 length, and serves * An implicit odp umem cannot be DMA mapped, has 0 length, and serves
* only as an anchor for the driver to hold onto the per_mm. FIXME: * only as an anchor for the driver to hold onto the per_mm. FIXME:
@ -77,7 +72,6 @@ struct ib_umem_odp {
*/ */
bool is_implicit_odp; bool is_implicit_odp;
struct completion notifier_completion;
unsigned int page_shift; unsigned int page_shift;
}; };
@ -89,13 +83,13 @@ static inline struct ib_umem_odp *to_ib_umem_odp(struct ib_umem *umem)
/* Returns the first page of an ODP umem. */ /* Returns the first page of an ODP umem. */
static inline unsigned long ib_umem_start(struct ib_umem_odp *umem_odp) static inline unsigned long ib_umem_start(struct ib_umem_odp *umem_odp)
{ {
return umem_odp->interval_tree.start; return umem_odp->notifier.interval_tree.start;
} }
/* Returns the address of the page after the last one of an ODP umem. */ /* Returns the address of the page after the last one of an ODP umem. */
static inline unsigned long ib_umem_end(struct ib_umem_odp *umem_odp) static inline unsigned long ib_umem_end(struct ib_umem_odp *umem_odp)
{ {
return umem_odp->interval_tree.last + 1; return umem_odp->notifier.interval_tree.last + 1;
} }
static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp *umem_odp) static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp *umem_odp)
@ -119,21 +113,15 @@ static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp *umem_odp)
#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
struct ib_ucontext_per_mm { struct ib_umem_odp *
struct mmu_notifier mn; ib_umem_odp_get(struct ib_udata *udata, unsigned long addr, size_t size,
struct pid *tgid; int access, const struct mmu_interval_notifier_ops *ops);
struct rb_root_cached umem_tree;
/* Protects umem_tree */
struct rw_semaphore umem_rwsem;
};
struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata, unsigned long addr,
size_t size, int access);
struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_udata *udata, struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_udata *udata,
int access); int access);
struct ib_umem_odp *ib_umem_odp_alloc_child(struct ib_umem_odp *root_umem, struct ib_umem_odp *
unsigned long addr, size_t size); ib_umem_odp_alloc_child(struct ib_umem_odp *root_umem, unsigned long addr,
size_t size,
const struct mmu_interval_notifier_ops *ops);
void ib_umem_odp_release(struct ib_umem_odp *umem_odp); void ib_umem_odp_release(struct ib_umem_odp *umem_odp);
int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset, int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
@ -143,39 +131,11 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset, void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
u64 bound); u64 bound);
typedef int (*umem_call_back)(struct ib_umem_odp *item, u64 start, u64 end,
void *cookie);
/*
* Call the callback on each ib_umem in the range. Returns the logical or of
* the return values of the functions called.
*/
int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root,
u64 start, u64 end,
umem_call_back cb,
bool blockable, void *cookie);
static inline int ib_umem_mmu_notifier_retry(struct ib_umem_odp *umem_odp,
unsigned long mmu_seq)
{
/*
* This code is strongly based on the KVM code from
* mmu_notifier_retry. Should be called with
* the relevant locks taken (umem_odp->umem_mutex
* and the ucontext umem_mutex semaphore locked for read).
*/
if (unlikely(umem_odp->notifiers_count))
return 1;
if (umem_odp->notifiers_seq != mmu_seq)
return 1;
return 0;
}
#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
static inline struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata, static inline struct ib_umem_odp *
unsigned long addr, ib_umem_odp_get(struct ib_udata *udata, unsigned long addr, size_t size,
size_t size, int access) int access, const struct mmu_interval_notifier_ops *ops)
{ {
return ERR_PTR(-EINVAL); return ERR_PTR(-EINVAL);
} }

2
include/rdma/ib_verbs.h
View File

@ -2451,8 +2451,6 @@ struct ib_device_ops {
u64 iova); u64 iova);
int (*unmap_fmr)(struct list_head *fmr_list); int (*unmap_fmr)(struct list_head *fmr_list);
int (*dealloc_fmr)(struct ib_fmr *fmr); int (*dealloc_fmr)(struct ib_fmr *fmr);
void (*invalidate_range)(struct ib_umem_odp *umem_odp,
unsigned long start, unsigned long end);
int (*attach_mcast)(struct ib_qp *qp, union ib_gid *gid, u16 lid); int (*attach_mcast)(struct ib_qp *qp, union ib_gid *gid, u16 lid);
int (*detach_mcast)(struct ib_qp *qp, union ib_gid *gid, u16 lid); int (*detach_mcast)(struct ib_qp *qp, union ib_gid *gid, u16 lid);
struct ib_xrcd *(*alloc_xrcd)(struct ib_device *device, struct ib_xrcd *(*alloc_xrcd)(struct ib_device *device,

1
kernel/fork.c
View File

@ -40,7 +40,6 @@
#include <linux/binfmts.h> #include <linux/binfmts.h>
#include <linux/mman.h> #include <linux/mman.h>
#include <linux/mmu_notifier.h> #include <linux/mmu_notifier.h>
#include <linux/hmm.h>
#include <linux/fs.h> #include <linux/fs.h>
#include <linux/mm.h> #include <linux/mm.h>
#include <linux/vmacache.h> #include <linux/vmacache.h>

2
mm/Kconfig
View File

@ -284,6 +284,7 @@ config VIRT_TO_BUS
config MMU_NOTIFIER config MMU_NOTIFIER
bool bool
select SRCU select SRCU
select INTERVAL_TREE
config KSM config KSM
bool "Enable KSM for page merging" bool "Enable KSM for page merging"
@ -674,7 +675,6 @@ config DEV_PAGEMAP_OPS
config HMM_MIRROR config HMM_MIRROR
bool bool
depends on MMU depends on MMU
depends on MMU_NOTIFIER
config DEVICE_PRIVATE config DEVICE_PRIVATE
bool "Unaddressable device memory (GPU memory, ...)" bool "Unaddressable device memory (GPU memory, ...)"

523
mm/hmm.c
View File

@ -26,193 +26,6 @@
#include <linux/mmu_notifier.h> #include <linux/mmu_notifier.h>
#include <linux/memory_hotplug.h> #include <linux/memory_hotplug.h>
static struct mmu_notifier *hmm_alloc_notifier(struct mm_struct *mm)
{
struct hmm *hmm;
hmm = kzalloc(sizeof(*hmm), GFP_KERNEL);
if (!hmm)
return ERR_PTR(-ENOMEM);
init_waitqueue_head(&hmm->wq);
INIT_LIST_HEAD(&hmm->mirrors);
init_rwsem(&hmm->mirrors_sem);
INIT_LIST_HEAD(&hmm->ranges);
spin_lock_init(&hmm->ranges_lock);
hmm->notifiers = 0;
return &hmm->mmu_notifier;
}
static void hmm_free_notifier(struct mmu_notifier *mn)
{
struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier);
WARN_ON(!list_empty(&hmm->ranges));
WARN_ON(!list_empty(&hmm->mirrors));
kfree(hmm);
}
static void hmm_release(struct mmu_notifier *mn, struct mm_struct *mm)
{
struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier);
struct hmm_mirror *mirror;
/*
* Since hmm_range_register() holds the mmget() lock hmm_release() is
* prevented as long as a range exists.
*/
WARN_ON(!list_empty_careful(&hmm->ranges));
down_read(&hmm->mirrors_sem);
list_for_each_entry(mirror, &hmm->mirrors, list) {
/*
* Note: The driver is not allowed to trigger
* hmm_mirror_unregister() from this thread.
*/
if (mirror->ops->release)
mirror->ops->release(mirror);
}
up_read(&hmm->mirrors_sem);
}
static void notifiers_decrement(struct hmm *hmm)
{
unsigned long flags;
spin_lock_irqsave(&hmm->ranges_lock, flags);
hmm->notifiers--;
if (!hmm->notifiers) {
struct hmm_range *range;
list_for_each_entry(range, &hmm->ranges, list) {
if (range->valid)
continue;
range->valid = true;
}
wake_up_all(&hmm->wq);
}
spin_unlock_irqrestore(&hmm->ranges_lock, flags);
}
static int hmm_invalidate_range_start(struct mmu_notifier *mn,
const struct mmu_notifier_range *nrange)
{
struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier);
struct hmm_mirror *mirror;
struct hmm_range *range;
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&hmm->ranges_lock, flags);
hmm->notifiers++;
list_for_each_entry(range, &hmm->ranges, list) {
if (nrange->end < range->start || nrange->start >= range->end)
continue;
range->valid = false;
}
spin_unlock_irqrestore(&hmm->ranges_lock, flags);
if (mmu_notifier_range_blockable(nrange))
down_read(&hmm->mirrors_sem);
else if (!down_read_trylock(&hmm->mirrors_sem)) {
ret = -EAGAIN;
goto out;
}
list_for_each_entry(mirror, &hmm->mirrors, list) {
int rc;
rc = mirror->ops->sync_cpu_device_pagetables(mirror, nrange);
if (rc) {
if (WARN_ON(mmu_notifier_range_blockable(nrange) ||
rc != -EAGAIN))
continue;
ret = -EAGAIN;
break;
}
}
up_read(&hmm->mirrors_sem);
out:
if (ret)
notifiers_decrement(hmm);
return ret;
}
static void hmm_invalidate_range_end(struct mmu_notifier *mn,
const struct mmu_notifier_range *nrange)
{
struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier);
notifiers_decrement(hmm);
}
static const struct mmu_notifier_ops hmm_mmu_notifier_ops = {
.release = hmm_release,
.invalidate_range_start = hmm_invalidate_range_start,
.invalidate_range_end = hmm_invalidate_range_end,
.alloc_notifier = hmm_alloc_notifier,
.free_notifier = hmm_free_notifier,
};
/*
* hmm_mirror_register() - register a mirror against an mm
*
* @mirror: new mirror struct to register
* @mm: mm to register against
* Return: 0 on success, -ENOMEM if no memory, -EINVAL if invalid arguments
*
* To start mirroring a process address space, the device driver must register
* an HMM mirror struct.
*
* The caller cannot unregister the hmm_mirror while any ranges are
* registered.
*
* Callers using this function must put a call to mmu_notifier_synchronize()
* in their module exit functions.
*/
int hmm_mirror_register(struct hmm_mirror *mirror, struct mm_struct *mm)
{
struct mmu_notifier *mn;
lockdep_assert_held_write(&mm->mmap_sem);
/* Sanity check */
if (!mm || !mirror || !mirror->ops)
return -EINVAL;
mn = mmu_notifier_get_locked(&hmm_mmu_notifier_ops, mm);
if (IS_ERR(mn))
return PTR_ERR(mn);
mirror->hmm = container_of(mn, struct hmm, mmu_notifier);
down_write(&mirror->hmm->mirrors_sem);
list_add(&mirror->list, &mirror->hmm->mirrors);
up_write(&mirror->hmm->mirrors_sem);
return 0;
}
EXPORT_SYMBOL(hmm_mirror_register);
/*
* hmm_mirror_unregister() - unregister a mirror
*
* @mirror: mirror struct to unregister
*
* Stop mirroring a process address space, and cleanup.
*/
void hmm_mirror_unregister(struct hmm_mirror *mirror)
{
struct hmm *hmm = mirror->hmm;
down_write(&hmm->mirrors_sem);
list_del(&mirror->list);
up_write(&hmm->mirrors_sem);
mmu_notifier_put(&hmm->mmu_notifier);
}
EXPORT_SYMBOL(hmm_mirror_unregister);
struct hmm_vma_walk { struct hmm_vma_walk {
struct hmm_range *range; struct hmm_range *range;
struct dev_pagemap *pgmap; struct dev_pagemap *pgmap;
@ -252,18 +65,15 @@ err:
return -EFAULT; return -EFAULT;
} }
static int hmm_pfns_bad(unsigned long addr, static int hmm_pfns_fill(unsigned long addr, unsigned long end,
unsigned long end, struct hmm_range *range, enum hmm_pfn_value_e value)
struct mm_walk *walk)
{ {
struct hmm_vma_walk *hmm_vma_walk = walk->private;
struct hmm_range *range = hmm_vma_walk->range;
uint64_t *pfns = range->pfns; uint64_t *pfns = range->pfns;
unsigned long i; unsigned long i;
i = (addr - range->start) >> PAGE_SHIFT; i = (addr - range->start) >> PAGE_SHIFT;
for (; addr < end; addr += PAGE_SIZE, i++) for (; addr < end; addr += PAGE_SIZE, i++)
pfns[i] = range->values[HMM_PFN_ERROR]; pfns[i] = range->values[value];
return 0; return 0;
} }
@ -532,9 +342,15 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr,
if (unlikely(!hmm_vma_walk->pgmap)) if (unlikely(!hmm_vma_walk->pgmap))
return -EBUSY; return -EBUSY;
} else if (IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) && pte_special(pte)) { } else if (IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) && pte_special(pte)) {
if (!is_zero_pfn(pte_pfn(pte))) {
*pfn = range->values[HMM_PFN_SPECIAL]; *pfn = range->values[HMM_PFN_SPECIAL];
return -EFAULT; return -EFAULT;
} }
/*
* Since each architecture defines a struct page for the zero
* page, just fall through and treat it like a normal page.
*/
}
*pfn = hmm_device_entry_from_pfn(range, pte_pfn(pte)) | cpu_flags; *pfn = hmm_device_entry_from_pfn(range, pte_pfn(pte)) | cpu_flags;
return 0; return 0;
@ -584,7 +400,7 @@ again:
} }
return 0; return 0;
} else if (!pmd_present(pmd)) } else if (!pmd_present(pmd))
return hmm_pfns_bad(start, end, walk); return hmm_pfns_fill(start, end, range, HMM_PFN_ERROR);
if (pmd_devmap(pmd) || pmd_trans_huge(pmd)) { if (pmd_devmap(pmd) || pmd_trans_huge(pmd)) {
/* /*
@ -612,7 +428,7 @@ again:
* recover. * recover.
*/ */
if (pmd_bad(pmd)) if (pmd_bad(pmd))
return hmm_pfns_bad(start, end, walk); return hmm_pfns_fill(start, end, range, HMM_PFN_ERROR);
ptep = pte_offset_map(pmdp, addr); ptep = pte_offset_map(pmdp, addr);
i = (addr - range->start) >> PAGE_SHIFT; i = (addr - range->start) >> PAGE_SHIFT;
@ -770,93 +586,55 @@ unlock:
#define hmm_vma_walk_hugetlb_entry NULL #define hmm_vma_walk_hugetlb_entry NULL
#endif /* CONFIG_HUGETLB_PAGE */ #endif /* CONFIG_HUGETLB_PAGE */
static void hmm_pfns_clear(struct hmm_range *range, static int hmm_vma_walk_test(unsigned long start, unsigned long end,
uint64_t *pfns, struct mm_walk *walk)
unsigned long addr,
unsigned long end)
{ {
for (; addr < end; addr += PAGE_SIZE, pfns++) struct hmm_vma_walk *hmm_vma_walk = walk->private;
*pfns = range->values[HMM_PFN_NONE]; struct hmm_range *range = hmm_vma_walk->range;
} struct vm_area_struct *vma = walk->vma;
/*
* hmm_range_register() - start tracking change to CPU page table over a range
* @range: range
* @mm: the mm struct for the range of virtual address
*
* Return: 0 on success, -EFAULT if the address space is no longer valid
*
* Track updates to the CPU page table see include/linux/hmm.h
*/
int hmm_range_register(struct hmm_range *range, struct hmm_mirror *mirror)
{
struct hmm *hmm = mirror->hmm;
unsigned long flags;
range->valid = false;
range->hmm = NULL;
if ((range->start & (PAGE_SIZE - 1)) || (range->end & (PAGE_SIZE - 1)))
return -EINVAL;
if (range->start >= range->end)
return -EINVAL;
/* Prevent hmm_release() from running while the range is valid */
if (!mmget_not_zero(hmm->mmu_notifier.mm))
return -EFAULT;
/* Initialize range to track CPU page table updates. */
spin_lock_irqsave(&hmm->ranges_lock, flags);
range->hmm = hmm;
list_add(&range->list, &hmm->ranges);
/* /*
* If there are any concurrent notifiers we have to wait for them for * Skip vma ranges that don't have struct page backing them or
* the range to be valid (see hmm_range_wait_until_valid()). * map I/O devices directly.
*/ */
if (!hmm->notifiers) if (vma->vm_flags & (VM_IO | VM_PFNMAP | VM_MIXEDMAP))
range->valid = true; return -EFAULT;
spin_unlock_irqrestore(&hmm->ranges_lock, flags);
/*
* If the vma does not allow read access, then assume that it does not
* allow write access either. HMM does not support architectures
* that allow write without read.
*/
if (!(vma->vm_flags & VM_READ)) {
bool fault, write_fault;
/*
* Check to see if a fault is requested for any page in the
* range.
*/
hmm_range_need_fault(hmm_vma_walk, range->pfns +
((start - range->start) >> PAGE_SHIFT),
(end - start) >> PAGE_SHIFT,
0, &fault, &write_fault);
if (fault || write_fault)
return -EFAULT;
hmm_pfns_fill(start, end, range, HMM_PFN_NONE);
hmm_vma_walk->last = end;
/* Skip this vma and continue processing the next vma. */
return 1;
}
return 0; return 0;
} }
EXPORT_SYMBOL(hmm_range_register);
/*
* hmm_range_unregister() - stop tracking change to CPU page table over a range
* @range: range
*
* Range struct is used to track updates to the CPU page table after a call to
* hmm_range_register(). See include/linux/hmm.h for how to use it.
*/
void hmm_range_unregister(struct hmm_range *range)
{
struct hmm *hmm = range->hmm;
unsigned long flags;
spin_lock_irqsave(&hmm->ranges_lock, flags);
list_del_init(&range->list);
spin_unlock_irqrestore(&hmm->ranges_lock, flags);
/* Drop reference taken by hmm_range_register() */
mmput(hmm->mmu_notifier.mm);
/*
* The range is now invalid and the ref on the hmm is dropped, so
* poison the pointer. Leave other fields in place, for the caller's
* use.
*/
range->valid = false;
memset(&range->hmm, POISON_INUSE, sizeof(range->hmm));
}
EXPORT_SYMBOL(hmm_range_unregister);
static const struct mm_walk_ops hmm_walk_ops = { static const struct mm_walk_ops hmm_walk_ops = {
.pud_entry = hmm_vma_walk_pud, .pud_entry = hmm_vma_walk_pud,
.pmd_entry = hmm_vma_walk_pmd, .pmd_entry = hmm_vma_walk_pmd,
.pte_hole = hmm_vma_walk_hole, .pte_hole = hmm_vma_walk_hole,
.hugetlb_entry = hmm_vma_walk_hugetlb_entry, .hugetlb_entry = hmm_vma_walk_hugetlb_entry,
.test_walk = hmm_vma_walk_test,
}; };
/** /**
@ -889,210 +667,27 @@ static const struct mm_walk_ops hmm_walk_ops = {
*/ */
long hmm_range_fault(struct hmm_range *range, unsigned int flags) long hmm_range_fault(struct hmm_range *range, unsigned int flags)
{ {
const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP; struct hmm_vma_walk hmm_vma_walk = {
unsigned long start = range->start, end; .range = range,
struct hmm_vma_walk hmm_vma_walk; .last = range->start,
struct hmm *hmm = range->hmm; .flags = flags,
struct vm_area_struct *vma; };
struct mm_struct *mm = range->notifier->mm;
int ret; int ret;
lockdep_assert_held(&hmm->mmu_notifier.mm->mmap_sem); lockdep_assert_held(&mm->mmap_sem);
do { do {
/* If range is no longer valid force retry. */ /* If range is no longer valid force retry. */
if (!range->valid) if (mmu_interval_check_retry(range->notifier,
range->notifier_seq))
return -EBUSY; return -EBUSY;
ret = walk_page_range(mm, hmm_vma_walk.last, range->end,
vma = find_vma(hmm->mmu_notifier.mm, start);
if (vma == NULL || (vma->vm_flags & device_vma))
return -EFAULT;
if (!(vma->vm_flags & VM_READ)) {
/*
* If vma do not allow read access, then assume that it
* does not allow write access, either. HMM does not
* support architecture that allow write without read.
*/
hmm_pfns_clear(range, range->pfns,
range->start, range->end);
return -EPERM;
}
hmm_vma_walk.pgmap = NULL;
hmm_vma_walk.last = start;
hmm_vma_walk.flags = flags;
hmm_vma_walk.range = range;
end = min(range->end, vma->vm_end);
walk_page_range(vma->vm_mm, start, end, &hmm_walk_ops,
&hmm_vma_walk);
do {
ret = walk_page_range(vma->vm_mm, start, end,
&hmm_walk_ops, &hmm_vma_walk); &hmm_walk_ops, &hmm_vma_walk);
start = hmm_vma_walk.last; } while (ret == -EBUSY);
/* Keep trying while the range is valid. */ if (ret)
} while (ret == -EBUSY && range->valid);
if (ret) {
unsigned long i;
i = (hmm_vma_walk.last - range->start) >> PAGE_SHIFT;
hmm_pfns_clear(range, &range->pfns[i],
hmm_vma_walk.last, range->end);
return ret; return ret;
}
start = end;
} while (start < range->end);
return (hmm_vma_walk.last - range->start) >> PAGE_SHIFT; return (hmm_vma_walk.last - range->start) >> PAGE_SHIFT;
} }
EXPORT_SYMBOL(hmm_range_fault); EXPORT_SYMBOL(hmm_range_fault);
/**
* hmm_range_dma_map - hmm_range_fault() and dma map page all in one.
* @range: range being faulted
* @device: device to map page to
* @daddrs: array of dma addresses for the mapped pages
* @flags: HMM_FAULT_*
*
* Return: the number of pages mapped on success (including zero), or any
* status return from hmm_range_fault() otherwise.
*/
long hmm_range_dma_map(struct hmm_range *range, struct device *device,
dma_addr_t *daddrs, unsigned int flags)
{
unsigned long i, npages, mapped;
long ret;
ret = hmm_range_fault(range, flags);
if (ret <= 0)
return ret ? ret : -EBUSY;
npages = (range->end - range->start) >> PAGE_SHIFT;
for (i = 0, mapped = 0; i < npages; ++i) {
enum dma_data_direction dir = DMA_TO_DEVICE;
struct page *page;
/*
* FIXME need to update DMA API to provide invalid DMA address
* value instead of a function to test dma address value. This
* would remove lot of dumb code duplicated accross many arch.
*
* For now setting it to 0 here is good enough as the pfns[]
* value is what is use to check what is valid and what isn't.
*/
daddrs[i] = 0;
page = hmm_device_entry_to_page(range, range->pfns[i]);
if (page == NULL)
continue;
/* Check if range is being invalidated */
if (!range->valid) {
ret = -EBUSY;
goto unmap;
}
/* If it is read and write than map bi-directional. */
if (range->pfns[i] & range->flags[HMM_PFN_WRITE])
dir = DMA_BIDIRECTIONAL;
daddrs[i] = dma_map_page(device, page, 0, PAGE_SIZE, dir);
if (dma_mapping_error(device, daddrs[i])) {
ret = -EFAULT;
goto unmap;
}
mapped++;
}
return mapped;
unmap:
for (npages = i, i = 0; (i < npages) && mapped; ++i) {
enum dma_data_direction dir = DMA_TO_DEVICE;
struct page *page;
page = hmm_device_entry_to_page(range, range->pfns[i]);
if (page == NULL)
continue;
if (dma_mapping_error(device, daddrs[i]))
continue;
/* If it is read and write than map bi-directional. */
if (range->pfns[i] & range->flags[HMM_PFN_WRITE])
dir = DMA_BIDIRECTIONAL;
dma_unmap_page(device, daddrs[i], PAGE_SIZE, dir);
mapped--;
}
return ret;
}
EXPORT_SYMBOL(hmm_range_dma_map);
/**
* hmm_range_dma_unmap() - unmap range of that was map with hmm_range_dma_map()
* @range: range being unmapped
* @device: device against which dma map was done
* @daddrs: dma address of mapped pages
* @dirty: dirty page if it had the write flag set
* Return: number of page unmapped on success, -EINVAL otherwise
*
* Note that caller MUST abide by mmu notifier or use HMM mirror and abide
* to the sync_cpu_device_pagetables() callback so that it is safe here to
* call set_page_dirty(). Caller must also take appropriate locks to avoid
* concurrent mmu notifier or sync_cpu_device_pagetables() to make progress.
*/
long hmm_range_dma_unmap(struct hmm_range *range,
struct device *device,
dma_addr_t *daddrs,
bool dirty)
{
unsigned long i, npages;
long cpages = 0;
/* Sanity check. */
if (range->end <= range->start)
return -EINVAL;
if (!daddrs)
return -EINVAL;
if (!range->pfns)
return -EINVAL;
npages = (range->end - range->start) >> PAGE_SHIFT;
for (i = 0; i < npages; ++i) {
enum dma_data_direction dir = DMA_TO_DEVICE;
struct page *page;
page = hmm_device_entry_to_page(range, range->pfns[i]);
if (page == NULL)
continue;
/* If it is read and write than map bi-directional. */
if (range->pfns[i] & range->flags[HMM_PFN_WRITE]) {
dir = DMA_BIDIRECTIONAL;
/*
* See comments in function description on why it is
* safe here to call set_page_dirty()
*/
if (dirty)
set_page_dirty(page);
}
/* Unmap and clear pfns/dma address */
dma_unmap_page(device, daddrs[i], PAGE_SIZE, dir);
range->pfns[i] = range->values[HMM_PFN_NONE];
/* FIXME see comments in hmm_vma_dma_map() */
daddrs[i] = 0;
cpages++;
}
return cpages;
}
EXPORT_SYMBOL(hmm_range_dma_unmap);

549
mm/mmu_notifier.c
View File

@ -12,6 +12,7 @@
#include <linux/export.h> #include <linux/export.h>
#include <linux/mm.h> #include <linux/mm.h>
#include <linux/err.h> #include <linux/err.h>
#include <linux/interval_tree.h>
#include <linux/srcu.h> #include <linux/srcu.h>
#include <linux/rcupdate.h> #include <linux/rcupdate.h>
#include <linux/sched.h> #include <linux/sched.h>
@ -27,6 +28,254 @@ struct lockdep_map __mmu_notifier_invalidate_range_start_map = {
}; };
#endif #endif
/*
* The mmu notifier_mm structure is allocated and installed in
* mm->mmu_notifier_mm inside the mm_take_all_locks() protected
* critical section and it's released only when mm_count reaches zero
* in mmdrop().
*/
struct mmu_notifier_mm {
/* all mmu notifiers registered in this mm are queued in this list */
struct hlist_head list;
bool has_itree;
/* to serialize the list modifications and hlist_unhashed */
spinlock_t lock;
unsigned long invalidate_seq;
unsigned long active_invalidate_ranges;
struct rb_root_cached itree;
wait_queue_head_t wq;
struct hlist_head deferred_list;
};
/*
* This is a collision-retry read-side/write-side 'lock', a lot like a
* seqcount, however this allows multiple write-sides to hold it at
* once. Conceptually the write side is protecting the values of the PTEs in
* this mm, such that PTES cannot be read into SPTEs (shadow PTEs) while any
* writer exists.
*
* Note that the core mm creates nested invalidate_range_start()/end() regions
* within the same thread, and runs invalidate_range_start()/end() in parallel
* on multiple CPUs. This is designed to not reduce concurrency or block
* progress on the mm side.
*
* As a secondary function, holding the full write side also serves to prevent
* writers for the itree, this is an optimization to avoid extra locking
* during invalidate_range_start/end notifiers.
*
* The write side has two states, fully excluded:
* - mm->active_invalidate_ranges != 0
* - mnn->invalidate_seq & 1 == True (odd)
* - some range on the mm_struct is being invalidated
* - the itree is not allowed to change
*
* And partially excluded:
* - mm->active_invalidate_ranges != 0
* - mnn->invalidate_seq & 1 == False (even)
* - some range on the mm_struct is being invalidated
* - the itree is allowed to change
*
* Operations on mmu_notifier_mm->invalidate_seq (under spinlock):
* seq |= 1 # Begin writing
* seq++ # Release the writing state
* seq & 1 # True if a writer exists
*
* The later state avoids some expensive work on inv_end in the common case of
* no mni monitoring the VA.
*/
static bool mn_itree_is_invalidating(struct mmu_notifier_mm *mmn_mm)
{
lockdep_assert_held(&mmn_mm->lock);
return mmn_mm->invalidate_seq & 1;
}
static struct mmu_interval_notifier *
mn_itree_inv_start_range(struct mmu_notifier_mm *mmn_mm,
const struct mmu_notifier_range *range,
unsigned long *seq)
{
struct interval_tree_node *node;
struct mmu_interval_notifier *res = NULL;
spin_lock(&mmn_mm->lock);
mmn_mm->active_invalidate_ranges++;
node = interval_tree_iter_first(&mmn_mm->itree, range->start,
range->end - 1);
if (node) {
mmn_mm->invalidate_seq |= 1;
res = container_of(node, struct mmu_interval_notifier,
interval_tree);
}
*seq = mmn_mm->invalidate_seq;
spin_unlock(&mmn_mm->lock);
return res;
}
static struct mmu_interval_notifier *
mn_itree_inv_next(struct mmu_interval_notifier *mni,
const struct mmu_notifier_range *range)
{
struct interval_tree_node *node;
node = interval_tree_iter_next(&mni->interval_tree, range->start,
range->end - 1);
if (!node)
return NULL;
return container_of(node, struct mmu_interval_notifier, interval_tree);
}
static void mn_itree_inv_end(struct mmu_notifier_mm *mmn_mm)
{
struct mmu_interval_notifier *mni;
struct hlist_node *next;
spin_lock(&mmn_mm->lock);
if (--mmn_mm->active_invalidate_ranges ||
!mn_itree_is_invalidating(mmn_mm)) {
spin_unlock(&mmn_mm->lock);
return;
}
/* Make invalidate_seq even */
mmn_mm->invalidate_seq++;
/*
* The inv_end incorporates a deferred mechanism like rtnl_unlock().
* Adds and removes are queued until the final inv_end happens then
* they are progressed. This arrangement for tree updates is used to
* avoid using a blocking lock during invalidate_range_start.
*/
hlist_for_each_entry_safe(mni, next, &mmn_mm->deferred_list,
deferred_item) {
if (RB_EMPTY_NODE(&mni->interval_tree.rb))
interval_tree_insert(&mni->interval_tree,
&mmn_mm->itree);
else
interval_tree_remove(&mni->interval_tree,
&mmn_mm->itree);
hlist_del(&mni->deferred_item);
}
spin_unlock(&mmn_mm->lock);
wake_up_all(&mmn_mm->wq);
}
/**
* mmu_interval_read_begin - Begin a read side critical section against a VA
* range
* mni: The range to use
*
* mmu_iterval_read_begin()/mmu_iterval_read_retry() implement a
* collision-retry scheme similar to seqcount for the VA range under mni. If
* the mm invokes invalidation during the critical section then
* mmu_interval_read_retry() will return true.
*
* This is useful to obtain shadow PTEs where teardown or setup of the SPTEs
* require a blocking context. The critical region formed by this can sleep,
* and the required 'user_lock' can also be a sleeping lock.
*
* The caller is required to provide a 'user_lock' to serialize both teardown
* and setup.
*
* The return value should be passed to mmu_interval_read_retry().
*/
unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
{
struct mmu_notifier_mm *mmn_mm = mni->mm->mmu_notifier_mm;
unsigned long seq;
bool is_invalidating;
/*
* If the mni has a different seq value under the user_lock than we
* started with then it has collided.
*
* If the mni currently has the same seq value as the mmn_mm seq, then
* it is currently between invalidate_start/end and is colliding.
*
* The locking looks broadly like this:
* mn_tree_invalidate_start(): mmu_interval_read_begin():
* spin_lock
* seq = READ_ONCE(mni->invalidate_seq);
* seq == mmn_mm->invalidate_seq
* spin_unlock
* spin_lock
* seq = ++mmn_mm->invalidate_seq
* spin_unlock
* op->invalidate_range():
* user_lock
* mmu_interval_set_seq()
* mni->invalidate_seq = seq
* user_unlock
*
* [Required: mmu_interval_read_retry() == true]
*
* mn_itree_inv_end():
* spin_lock
* seq = ++mmn_mm->invalidate_seq
* spin_unlock
*
* user_lock
* mmu_interval_read_retry():
* mni->invalidate_seq != seq
* user_unlock
*
* Barriers are not needed here as any races here are closed by an
* eventual mmu_interval_read_retry(), which provides a barrier via the
* user_lock.
*/
spin_lock(&mmn_mm->lock);
/* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */
seq = READ_ONCE(mni->invalidate_seq);
is_invalidating = seq == mmn_mm->invalidate_seq;
spin_unlock(&mmn_mm->lock);
/*
* mni->invalidate_seq must always be set to an odd value via
* mmu_interval_set_seq() using the provided cur_seq from
* mn_itree_inv_start_range(). This ensures that if seq does wrap we
* will always clear the below sleep in some reasonable time as
* mmn_mm->invalidate_seq is even in the idle state.
*/
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
if (is_invalidating)
wait_event(mmn_mm->wq,
READ_ONCE(mmn_mm->invalidate_seq) != seq);
/*
* Notice that mmu_interval_read_retry() can already be true at this
* point, avoiding loops here allows the caller to provide a global
* time bound.
*/
return seq;
}
EXPORT_SYMBOL_GPL(mmu_interval_read_begin);
static void mn_itree_release(struct mmu_notifier_mm *mmn_mm,
struct mm_struct *mm)
{
struct mmu_notifier_range range = {
.flags = MMU_NOTIFIER_RANGE_BLOCKABLE,
.event = MMU_NOTIFY_RELEASE,
.mm = mm,
.start = 0,
.end = ULONG_MAX,
};
struct mmu_interval_notifier *mni;
unsigned long cur_seq;
bool ret;
for (mni = mn_itree_inv_start_range(mmn_mm, &range, &cur_seq); mni;
mni = mn_itree_inv_next(mni, &range)) {
ret = mni->ops->invalidate(mni, &range, cur_seq);
WARN_ON(!ret);
}
mn_itree_inv_end(mmn_mm);
}
/* /*
* This function can't run concurrently against mmu_notifier_register * This function can't run concurrently against mmu_notifier_register
* because mm->mm_users > 0 during mmu_notifier_register and exit_mmap * because mm->mm_users > 0 during mmu_notifier_register and exit_mmap
@ -39,7 +288,8 @@ struct lockdep_map __mmu_notifier_invalidate_range_start_map = {
* can't go away from under us as exit_mmap holds an mm_count pin * can't go away from under us as exit_mmap holds an mm_count pin
* itself. * itself.
*/ */
void __mmu_notifier_release(struct mm_struct *mm) static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
struct mm_struct *mm)
{ {
struct mmu_notifier *mn; struct mmu_notifier *mn;
int id; int id;
@ -49,7 +299,7 @@ void __mmu_notifier_release(struct mm_struct *mm)
* ->release returns. * ->release returns.
*/ */
id = srcu_read_lock(&srcu); id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) hlist_for_each_entry_rcu(mn, &mmn_mm->list, hlist)
/* /*
* If ->release runs before mmu_notifier_unregister it must be * If ->release runs before mmu_notifier_unregister it must be
* handled, as it's the only way for the driver to flush all * handled, as it's the only way for the driver to flush all
@ -59,10 +309,9 @@ void __mmu_notifier_release(struct mm_struct *mm)
if (mn->ops->release) if (mn->ops->release)
mn->ops->release(mn, mm); mn->ops->release(mn, mm);
spin_lock(&mm->mmu_notifier_mm->lock); spin_lock(&mmn_mm->lock);
while (unlikely(!hlist_empty(&mm->mmu_notifier_mm->list))) { while (unlikely(!hlist_empty(&mmn_mm->list))) {
mn = hlist_entry(mm->mmu_notifier_mm->list.first, mn = hlist_entry(mmn_mm->list.first, struct mmu_notifier,
struct mmu_notifier,
hlist); hlist);
/* /*
* We arrived before mmu_notifier_unregister so * We arrived before mmu_notifier_unregister so
@ -72,7 +321,7 @@ void __mmu_notifier_release(struct mm_struct *mm)
*/ */
hlist_del_init_rcu(&mn->hlist); hlist_del_init_rcu(&mn->hlist);
} }
spin_unlock(&mm->mmu_notifier_mm->lock); spin_unlock(&mmn_mm->lock);
srcu_read_unlock(&srcu, id); srcu_read_unlock(&srcu, id);
/* /*
@ -87,6 +336,17 @@ void __mmu_notifier_release(struct mm_struct *mm)
synchronize_srcu(&srcu); synchronize_srcu(&srcu);
} }
void __mmu_notifier_release(struct mm_struct *mm)
{
struct mmu_notifier_mm *mmn_mm = mm->mmu_notifier_mm;
if (mmn_mm->has_itree)
mn_itree_release(mmn_mm, mm);
if (!hlist_empty(&mmn_mm->list))
mn_hlist_release(mmn_mm, mm);
}
/* /*
* If no young bitflag is supported by the hardware, ->clear_flush_young can * If no young bitflag is supported by the hardware, ->clear_flush_young can
* unmap the address and return 1 or 0 depending if the mapping previously * unmap the address and return 1 or 0 depending if the mapping previously
@ -159,14 +419,43 @@ void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
srcu_read_unlock(&srcu, id); srcu_read_unlock(&srcu, id);
} }
int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range) static int mn_itree_invalidate(struct mmu_notifier_mm *mmn_mm,
const struct mmu_notifier_range *range)
{
struct mmu_interval_notifier *mni;
unsigned long cur_seq;
for (mni = mn_itree_inv_start_range(mmn_mm, range, &cur_seq); mni;
mni = mn_itree_inv_next(mni, range)) {
bool ret;
ret = mni->ops->invalidate(mni, range, cur_seq);
if (!ret) {
if (WARN_ON(mmu_notifier_range_blockable(range)))
continue;
goto out_would_block;
}
}
return 0;
out_would_block:
/*
* On -EAGAIN the non-blocking caller is not allowed to call
* invalidate_range_end()
*/
mn_itree_inv_end(mmn_mm);
return -EAGAIN;
}
static int mn_hlist_invalidate_range_start(struct mmu_notifier_mm *mmn_mm,
struct mmu_notifier_range *range)
{ {
struct mmu_notifier *mn; struct mmu_notifier *mn;
int ret = 0; int ret = 0;
int id; int id;
id = srcu_read_lock(&srcu); id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &range->mm->mmu_notifier_mm->list, hlist) { hlist_for_each_entry_rcu(mn, &mmn_mm->list, hlist) {
if (mn->ops->invalidate_range_start) { if (mn->ops->invalidate_range_start) {
int _ret; int _ret;
@ -190,15 +479,30 @@ int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
return ret; return ret;
} }
void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range, int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
{
struct mmu_notifier_mm *mmn_mm = range->mm->mmu_notifier_mm;
int ret;
if (mmn_mm->has_itree) {
ret = mn_itree_invalidate(mmn_mm, range);
if (ret)
return ret;
}
if (!hlist_empty(&mmn_mm->list))
return mn_hlist_invalidate_range_start(mmn_mm, range);
return 0;
}
static void mn_hlist_invalidate_end(struct mmu_notifier_mm *mmn_mm,
struct mmu_notifier_range *range,
bool only_end) bool only_end)
{ {
struct mmu_notifier *mn; struct mmu_notifier *mn;
int id; int id;
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
id = srcu_read_lock(&srcu); id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &range->mm->mmu_notifier_mm->list, hlist) { hlist_for_each_entry_rcu(mn, &mmn_mm->list, hlist) {
/* /*
* Call invalidate_range here too to avoid the need for the * Call invalidate_range here too to avoid the need for the
* subsystem of having to register an invalidate_range_end * subsystem of having to register an invalidate_range_end
@ -225,6 +529,19 @@ void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range,
} }
} }
srcu_read_unlock(&srcu, id); srcu_read_unlock(&srcu, id);
}
void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range,
bool only_end)
{
struct mmu_notifier_mm *mmn_mm = range->mm->mmu_notifier_mm;
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
if (mmn_mm->has_itree)
mn_itree_inv_end(mmn_mm);
if (!hlist_empty(&mmn_mm->list))
mn_hlist_invalidate_end(mmn_mm, range, only_end);
lock_map_release(&__mmu_notifier_invalidate_range_start_map); lock_map_release(&__mmu_notifier_invalidate_range_start_map);
} }
@ -243,8 +560,9 @@ void __mmu_notifier_invalidate_range(struct mm_struct *mm,
} }
/* /*
* Same as mmu_notifier_register but here the caller must hold the * Same as mmu_notifier_register but here the caller must hold the mmap_sem in
* mmap_sem in write mode. * write mode. A NULL mn signals the notifier is being registered for itree
* mode.
*/ */
int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm) int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
{ {
@ -261,9 +579,6 @@ int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
fs_reclaim_release(GFP_KERNEL); fs_reclaim_release(GFP_KERNEL);
} }
mn->mm = mm;
mn->users = 1;
if (!mm->mmu_notifier_mm) { if (!mm->mmu_notifier_mm) {
/* /*
* kmalloc cannot be called under mm_take_all_locks(), but we * kmalloc cannot be called under mm_take_all_locks(), but we
@ -271,21 +586,22 @@ int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
* the write side of the mmap_sem. * the write side of the mmap_sem.
*/ */
mmu_notifier_mm = mmu_notifier_mm =
kmalloc(sizeof(struct mmu_notifier_mm), GFP_KERNEL); kzalloc(sizeof(struct mmu_notifier_mm), GFP_KERNEL);
if (!mmu_notifier_mm) if (!mmu_notifier_mm)
return -ENOMEM; return -ENOMEM;
INIT_HLIST_HEAD(&mmu_notifier_mm->list); INIT_HLIST_HEAD(&mmu_notifier_mm->list);
spin_lock_init(&mmu_notifier_mm->lock); spin_lock_init(&mmu_notifier_mm->lock);
mmu_notifier_mm->invalidate_seq = 2;
mmu_notifier_mm->itree = RB_ROOT_CACHED;
init_waitqueue_head(&mmu_notifier_mm->wq);
INIT_HLIST_HEAD(&mmu_notifier_mm->deferred_list);
} }
ret = mm_take_all_locks(mm); ret = mm_take_all_locks(mm);
if (unlikely(ret)) if (unlikely(ret))
goto out_clean; goto out_clean;
/* Pairs with the mmdrop in mmu_notifier_unregister_* */
mmgrab(mm);
/* /*
* Serialize the update against mmu_notifier_unregister. A * Serialize the update against mmu_notifier_unregister. A
* side note: mmu_notifier_release can't run concurrently with * side note: mmu_notifier_release can't run concurrently with
@ -293,13 +609,28 @@ int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
* current->mm or explicitly with get_task_mm() or similar). * current->mm or explicitly with get_task_mm() or similar).
* We can't race against any other mmu notifier method either * We can't race against any other mmu notifier method either
* thanks to mm_take_all_locks(). * thanks to mm_take_all_locks().
*
* release semantics on the initialization of the mmu_notifier_mm's
* contents are provided for unlocked readers. acquire can only be
* used while holding the mmgrab or mmget, and is safe because once
* created the mmu_notififer_mm is not freed until the mm is
* destroyed. As above, users holding the mmap_sem or one of the
* mm_take_all_locks() do not need to use acquire semantics.
*/ */
if (mmu_notifier_mm) if (mmu_notifier_mm)
mm->mmu_notifier_mm = mmu_notifier_mm; smp_store_release(&mm->mmu_notifier_mm, mmu_notifier_mm);
if (mn) {
/* Pairs with the mmdrop in mmu_notifier_unregister_* */
mmgrab(mm);
mn->mm = mm;
mn->users = 1;
spin_lock(&mm->mmu_notifier_mm->lock); spin_lock(&mm->mmu_notifier_mm->lock);
hlist_add_head_rcu(&mn->hlist, &mm->mmu_notifier_mm->list); hlist_add_head_rcu(&mn->hlist, &mm->mmu_notifier_mm->list);
spin_unlock(&mm->mmu_notifier_mm->lock); spin_unlock(&mm->mmu_notifier_mm->lock);
} else
mm->mmu_notifier_mm->has_itree = true;
mm_drop_all_locks(mm); mm_drop_all_locks(mm);
BUG_ON(atomic_read(&mm->mm_users) <= 0); BUG_ON(atomic_read(&mm->mm_users) <= 0);
@ -516,6 +847,180 @@ out_unlock:
} }
EXPORT_SYMBOL_GPL(mmu_notifier_put); EXPORT_SYMBOL_GPL(mmu_notifier_put);
static int __mmu_interval_notifier_insert(
struct mmu_interval_notifier *mni, struct mm_struct *mm,
struct mmu_notifier_mm *mmn_mm, unsigned long start,
unsigned long length, const struct mmu_interval_notifier_ops *ops)
{
mni->mm = mm;
mni->ops = ops;
RB_CLEAR_NODE(&mni->interval_tree.rb);
mni->interval_tree.start = start;
/*
* Note that the representation of the intervals in the interval tree
* considers the ending point as contained in the interval.
*/
if (length == 0 ||
check_add_overflow(start, length - 1, &mni->interval_tree.last))
return -EOVERFLOW;
/* Must call with a mmget() held */
if (WARN_ON(atomic_read(&mm->mm_count) <= 0))
return -EINVAL;
/* pairs with mmdrop in mmu_interval_notifier_remove() */
mmgrab(mm);
/*
* If some invalidate_range_start/end region is going on in parallel
* we don't know what VA ranges are affected, so we must assume this
* new range is included.
*
* If the itree is invalidating then we are not allowed to change
* it. Retrying until invalidation is done is tricky due to the
* possibility for live lock, instead defer the add to
* mn_itree_inv_end() so this algorithm is deterministic.
*
* In all cases the value for the mni->invalidate_seq should be
* odd, see mmu_interval_read_begin()
*/
spin_lock(&mmn_mm->lock);
if (mmn_mm->active_invalidate_ranges) {
if (mn_itree_is_invalidating(mmn_mm))
hlist_add_head(&mni->deferred_item,
&mmn_mm->deferred_list);
else {
mmn_mm->invalidate_seq |= 1;
interval_tree_insert(&mni->interval_tree,
&mmn_mm->itree);
}
mni->invalidate_seq = mmn_mm->invalidate_seq;
} else {
WARN_ON(mn_itree_is_invalidating(mmn_mm));
/*
* The starting seq for a mni not under invalidation should be
* odd, not equal to the current invalidate_seq and
* invalidate_seq should not 'wrap' to the new seq any time
* soon.
*/
mni->invalidate_seq = mmn_mm->invalidate_seq - 1;
interval_tree_insert(&mni->interval_tree, &mmn_mm->itree);
}
spin_unlock(&mmn_mm->lock);
return 0;
}
/**
* mmu_interval_notifier_insert - Insert an interval notifier
* @mni: Interval notifier to register
* @start: Starting virtual address to monitor
* @length: Length of the range to monitor
* @mm : mm_struct to attach to
*
* This function subscribes the interval notifier for notifications from the
* mm. Upon return the ops related to mmu_interval_notifier will be called
* whenever an event that intersects with the given range occurs.
*
* Upon return the range_notifier may not be present in the interval tree yet.
* The caller must use the normal interval notifier read flow via
* mmu_interval_read_begin() to establish SPTEs for this range.
*/
int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
struct mm_struct *mm, unsigned long start,
unsigned long length,
const struct mmu_interval_notifier_ops *ops)
{
struct mmu_notifier_mm *mmn_mm;
int ret;
might_lock(&mm->mmap_sem);
mmn_mm = smp_load_acquire(&mm->mmu_notifier_mm);
if (!mmn_mm || !mmn_mm->has_itree) {
ret = mmu_notifier_register(NULL, mm);
if (ret)
return ret;
mmn_mm = mm->mmu_notifier_mm;
}
return __mmu_interval_notifier_insert(mni, mm, mmn_mm, start, length,
ops);
}
EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert);
int mmu_interval_notifier_insert_locked(
struct mmu_interval_notifier *mni, struct mm_struct *mm,
unsigned long start, unsigned long length,
const struct mmu_interval_notifier_ops *ops)
{
struct mmu_notifier_mm *mmn_mm;
int ret;
lockdep_assert_held_write(&mm->mmap_sem);
mmn_mm = mm->mmu_notifier_mm;
if (!mmn_mm || !mmn_mm->has_itree) {
ret = __mmu_notifier_register(NULL, mm);
if (ret)
return ret;
mmn_mm = mm->mmu_notifier_mm;
}
return __mmu_interval_notifier_insert(mni, mm, mmn_mm, start, length,
ops);
}
EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert_locked);
/**
* mmu_interval_notifier_remove - Remove a interval notifier
* @mni: Interval notifier to unregister
*
* This function must be paired with mmu_interval_notifier_insert(). It cannot
* be called from any ops callback.
*
* Once this returns ops callbacks are no longer running on other CPUs and
* will not be called in future.
*/
void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni)
{
struct mm_struct *mm = mni->mm;
struct mmu_notifier_mm *mmn_mm = mm->mmu_notifier_mm;
unsigned long seq = 0;
might_sleep();
spin_lock(&mmn_mm->lock);
if (mn_itree_is_invalidating(mmn_mm)) {
/*
* remove is being called after insert put this on the
* deferred list, but before the deferred list was processed.
*/
if (RB_EMPTY_NODE(&mni->interval_tree.rb)) {
hlist_del(&mni->deferred_item);
} else {
hlist_add_head(&mni->deferred_item,
&mmn_mm->deferred_list);
seq = mmn_mm->invalidate_seq;
}
} else {
WARN_ON(RB_EMPTY_NODE(&mni->interval_tree.rb));
interval_tree_remove(&mni->interval_tree, &mmn_mm->itree);
}
spin_unlock(&mmn_mm->lock);
/*
* The possible sleep on progress in the invalidation requires the
* caller not hold any locks held by invalidation callbacks.
*/
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
if (seq)
wait_event(mmn_mm->wq,
READ_ONCE(mmn_mm->invalidate_seq) != seq);
/* pairs with mmgrab in mmu_interval_notifier_insert() */
mmdrop(mm);
}
EXPORT_SYMBOL_GPL(mmu_interval_notifier_remove);
/** /**
* mmu_notifier_synchronize - Ensure all mmu_notifiers are freed * mmu_notifier_synchronize - Ensure all mmu_notifiers are freed
* *