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OpenCloudOS-Kernel/drivers/iommu/intel/svm.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright © 2015 Intel Corporation.
*
* Authors: David Woodhouse <dwmw2@infradead.org>
*/
#include <linux/intel-iommu.h>
#include <linux/mmu_notifier.h>
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/slab.h>
#include <linux/intel-svm.h>
#include <linux/rculist.h>
#include <linux/pci.h>
#include <linux/pci-ats.h>
#include <linux/dmar.h>
#include <linux/interrupt.h>
#include <linux/mm_types.h>
#include <linux/ioasid.h>
#include <asm/page.h>
#include <asm/fpu/api.h>
#include "pasid.h"
static irqreturn_t prq_event_thread(int irq, void *d);
static void intel_svm_drain_prq(struct device *dev, u32 pasid);
#define PRQ_ORDER 0
int intel_svm_enable_prq(struct intel_iommu *iommu)
{
struct page *pages;
int irq, ret;
pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, PRQ_ORDER);
if (!pages) {
pr_warn("IOMMU: %s: Failed to allocate page request queue\n",
iommu->name);
return -ENOMEM;
}
iommu->prq = page_address(pages);
irq = dmar_alloc_hwirq(DMAR_UNITS_SUPPORTED + iommu->seq_id, iommu->node, iommu);
if (irq <= 0) {
pr_err("IOMMU: %s: Failed to create IRQ vector for page request queue\n",
iommu->name);
ret = -EINVAL;
err:
free_pages((unsigned long)iommu->prq, PRQ_ORDER);
iommu->prq = NULL;
return ret;
}
iommu->pr_irq = irq;
snprintf(iommu->prq_name, sizeof(iommu->prq_name), "dmar%d-prq", iommu->seq_id);
ret = request_threaded_irq(irq, NULL, prq_event_thread, IRQF_ONESHOT,
iommu->prq_name, iommu);
if (ret) {
pr_err("IOMMU: %s: Failed to request IRQ for page request queue\n",
iommu->name);
dmar_free_hwirq(irq);
iommu->pr_irq = 0;
goto err;
}
dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL);
dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL);
dmar_writeq(iommu->reg + DMAR_PQA_REG, virt_to_phys(iommu->prq) | PRQ_ORDER);
init_completion(&iommu->prq_complete);
return 0;
}
int intel_svm_finish_prq(struct intel_iommu *iommu)
{
dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL);
dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL);
dmar_writeq(iommu->reg + DMAR_PQA_REG, 0ULL);
if (iommu->pr_irq) {
free_irq(iommu->pr_irq, iommu);
dmar_free_hwirq(iommu->pr_irq);
iommu->pr_irq = 0;
}
free_pages((unsigned long)iommu->prq, PRQ_ORDER);
iommu->prq = NULL;
return 0;
}
static inline bool intel_svm_capable(struct intel_iommu *iommu)
{
return iommu->flags & VTD_FLAG_SVM_CAPABLE;
}
void intel_svm_check(struct intel_iommu *iommu)
{
if (!pasid_supported(iommu))
return;
if (cpu_feature_enabled(X86_FEATURE_GBPAGES) &&
!cap_fl1gp_support(iommu->cap)) {
pr_err("%s SVM disabled, incompatible 1GB page capability\n",
iommu->name);
return;
}
if (cpu_feature_enabled(X86_FEATURE_LA57) &&
!cap_5lp_support(iommu->cap)) {
pr_err("%s SVM disabled, incompatible paging mode\n",
iommu->name);
return;
}
iommu->flags |= VTD_FLAG_SVM_CAPABLE;
}
static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_dev *sdev,
unsigned long address, unsigned long pages, int ih)
{
struct qi_desc desc;
if (pages == -1) {
desc.qw0 = QI_EIOTLB_PASID(svm->pasid) |
QI_EIOTLB_DID(sdev->did) |
QI_EIOTLB_GRAN(QI_GRAN_NONG_PASID) |
QI_EIOTLB_TYPE;
desc.qw1 = 0;
} else {
int mask = ilog2(__roundup_pow_of_two(pages));
desc.qw0 = QI_EIOTLB_PASID(svm->pasid) |
QI_EIOTLB_DID(sdev->did) |
QI_EIOTLB_GRAN(QI_GRAN_PSI_PASID) |
QI_EIOTLB_TYPE;
desc.qw1 = QI_EIOTLB_ADDR(address) |
QI_EIOTLB_IH(ih) |
QI_EIOTLB_AM(mask);
}
desc.qw2 = 0;
desc.qw3 = 0;
qi_submit_sync(svm->iommu, &desc, 1, 0);
if (sdev->dev_iotlb) {
desc.qw0 = QI_DEV_EIOTLB_PASID(svm->pasid) |
QI_DEV_EIOTLB_SID(sdev->sid) |
QI_DEV_EIOTLB_QDEP(sdev->qdep) |
QI_DEIOTLB_TYPE;
if (pages == -1) {
desc.qw1 = QI_DEV_EIOTLB_ADDR(-1ULL >> 1) |
QI_DEV_EIOTLB_SIZE;
} else if (pages > 1) {
/* The least significant zero bit indicates the size. So,
* for example, an "address" value of 0x12345f000 will
* flush from 0x123440000 to 0x12347ffff (256KiB). */
unsigned long last = address + ((unsigned long)(pages - 1) << VTD_PAGE_SHIFT);
unsigned long mask = __rounddown_pow_of_two(address ^ last);
desc.qw1 = QI_DEV_EIOTLB_ADDR((address & ~mask) |
(mask - 1)) | QI_DEV_EIOTLB_SIZE;
} else {
desc.qw1 = QI_DEV_EIOTLB_ADDR(address);
}
desc.qw2 = 0;
desc.qw3 = 0;
qi_submit_sync(svm->iommu, &desc, 1, 0);
}
}
static void intel_flush_svm_range(struct intel_svm *svm, unsigned long address,
unsigned long pages, int ih)
{
struct intel_svm_dev *sdev;
rcu_read_lock();
list_for_each_entry_rcu(sdev, &svm->devs, list)
intel_flush_svm_range_dev(svm, sdev, address, pages, ih);
rcu_read_unlock();
}
/* Pages have been freed at this point */
static void intel_invalidate_range(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start, unsigned long end)
{
struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
intel_flush_svm_range(svm, start,
(end - start + PAGE_SIZE - 1) >> VTD_PAGE_SHIFT, 0);
}
static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
{
struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
struct intel_svm_dev *sdev;
/* This might end up being called from exit_mmap(), *before* the page
* tables are cleared. And __mmu_notifier_release() will delete us from
* the list of notifiers so that our invalidate_range() callback doesn't
* get called when the page tables are cleared. So we need to protect
* against hardware accessing those page tables.
*
* We do it by clearing the entry in the PASID table and then flushing
* the IOTLB and the PASID table caches. This might upset hardware;
* perhaps we'll want to point the PASID to a dummy PGD (like the zero
* page) so that we end up taking a fault that the hardware really
* *has* to handle gracefully without affecting other processes.
*/
rcu_read_lock();
list_for_each_entry_rcu(sdev, &svm->devs, list)
intel_pasid_tear_down_entry(svm->iommu, sdev->dev,
svm->pasid, true);
rcu_read_unlock();
}
static const struct mmu_notifier_ops intel_mmuops = {
.release = intel_mm_release,
.invalidate_range = intel_invalidate_range,
};
static DEFINE_MUTEX(pasid_mutex);
static LIST_HEAD(global_svm_list);
#define for_each_svm_dev(sdev, svm, d) \
list_for_each_entry((sdev), &(svm)->devs, list) \
if ((d) != (sdev)->dev) {} else
static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid,
struct intel_svm **rsvm,
struct intel_svm_dev **rsdev)
{
struct intel_svm_dev *d, *sdev = NULL;
struct intel_svm *svm;
/* The caller should hold the pasid_mutex lock */
if (WARN_ON(!mutex_is_locked(&pasid_mutex)))
return -EINVAL;
if (pasid == INVALID_IOASID || pasid >= PASID_MAX)
return -EINVAL;
svm = ioasid_find(NULL, pasid, NULL);
if (IS_ERR(svm))
return PTR_ERR(svm);
if (!svm)
goto out;
/*
* If we found svm for the PASID, there must be at least one device
* bond.
*/
if (WARN_ON(list_empty(&svm->devs)))
return -EINVAL;
rcu_read_lock();
list_for_each_entry_rcu(d, &svm->devs, list) {
if (d->dev == dev) {
sdev = d;
break;
}
}
rcu_read_unlock();
out:
*rsvm = svm;
*rsdev = sdev;
return 0;
}
int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
struct iommu_gpasid_bind_data *data)
{
struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
struct intel_svm_dev *sdev = NULL;
struct dmar_domain *dmar_domain;
struct device_domain_info *info;
struct intel_svm *svm = NULL;
int ret = 0;
if (WARN_ON(!iommu) || !data)
return -EINVAL;
if (data->format != IOMMU_PASID_FORMAT_INTEL_VTD)
return -EINVAL;
/* IOMMU core ensures argsz is more than the start of the union */
if (data->argsz < offsetofend(struct iommu_gpasid_bind_data, vendor.vtd))
return -EINVAL;
/* Make sure no undefined flags are used in vendor data */
if (data->vendor.vtd.flags & ~(IOMMU_SVA_VTD_GPASID_LAST - 1))
return -EINVAL;
if (!dev_is_pci(dev))
return -ENOTSUPP;
/* VT-d supports devices with full 20 bit PASIDs only */
if (pci_max_pasids(to_pci_dev(dev)) != PASID_MAX)
return -EINVAL;
/*
* We only check host PASID range, we have no knowledge to check
* guest PASID range.
*/
if (data->hpasid <= 0 || data->hpasid >= PASID_MAX)
return -EINVAL;
info = get_domain_info(dev);
if (!info)
return -EINVAL;
dmar_domain = to_dmar_domain(domain);
mutex_lock(&pasid_mutex);
ret = pasid_to_svm_sdev(dev, data->hpasid, &svm, &sdev);
if (ret)
goto out;
if (sdev) {
/*
* Do not allow multiple bindings of the same device-PASID since
* there is only one SL page tables per PASID. We may revisit
* once sharing PGD across domains are supported.
*/
dev_warn_ratelimited(dev, "Already bound with PASID %u\n",
svm->pasid);
ret = -EBUSY;
goto out;
}
if (!svm) {
/* We come here when PASID has never been bond to a device. */
svm = kzalloc(sizeof(*svm), GFP_KERNEL);
if (!svm) {
ret = -ENOMEM;
goto out;
}
/* REVISIT: upper layer/VFIO can track host process that bind
* the PASID. ioasid_set = mm might be sufficient for vfio to
* check pasid VMM ownership. We can drop the following line
* once VFIO and IOASID set check is in place.
*/
svm->mm = get_task_mm(current);
svm->pasid = data->hpasid;
if (data->flags & IOMMU_SVA_GPASID_VAL) {
svm->gpasid = data->gpasid;
svm->flags |= SVM_FLAG_GUEST_PASID;
}
ioasid_set_data(data->hpasid, svm);
INIT_LIST_HEAD_RCU(&svm->devs);
mmput(svm->mm);
}
sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);
if (!sdev) {
ret = -ENOMEM;
goto out;
}
sdev->dev = dev;
sdev->sid = PCI_DEVID(info->bus, info->devfn);
/* Only count users if device has aux domains */
if (iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX))
sdev->users = 1;
/* Set up device context entry for PASID if not enabled already */
ret = intel_iommu_enable_pasid(iommu, sdev->dev);
if (ret) {
dev_err_ratelimited(dev, "Failed to enable PASID capability\n");
kfree(sdev);
goto out;
}
/*
* PASID table is per device for better security. Therefore, for
* each bind of a new device even with an existing PASID, we need to
* call the nested mode setup function here.
*/
spin_lock(&iommu->lock);
ret = intel_pasid_setup_nested(iommu, dev,
(pgd_t *)(uintptr_t)data->gpgd,
data->hpasid, &data->vendor.vtd, dmar_domain,
data->addr_width);
spin_unlock(&iommu->lock);
if (ret) {
dev_err_ratelimited(dev, "Failed to set up PASID %llu in nested mode, Err %d\n",
data->hpasid, ret);
/*
* PASID entry should be in cleared state if nested mode
* set up failed. So we only need to clear IOASID tracking
* data such that free call will succeed.
*/
kfree(sdev);
goto out;
}
svm->flags |= SVM_FLAG_GUEST_MODE;
init_rcu_head(&sdev->rcu);
list_add_rcu(&sdev->list, &svm->devs);
out:
if (!IS_ERR_OR_NULL(svm) && list_empty(&svm->devs)) {
ioasid_set_data(data->hpasid, NULL);
kfree(svm);
}
mutex_unlock(&pasid_mutex);
return ret;
}
int intel_svm_unbind_gpasid(struct device *dev, u32 pasid)
{
struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
struct intel_svm_dev *sdev;
struct intel_svm *svm;
int ret;
if (WARN_ON(!iommu))
return -EINVAL;
mutex_lock(&pasid_mutex);
ret = pasid_to_svm_sdev(dev, pasid, &svm, &sdev);
if (ret)
goto out;
if (sdev) {
if (iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX))
sdev->users--;
if (!sdev->users) {
list_del_rcu(&sdev->list);
intel_pasid_tear_down_entry(iommu, dev,
svm->pasid, false);
intel_svm_drain_prq(dev, svm->pasid);
kfree_rcu(sdev, rcu);
if (list_empty(&svm->devs)) {
/*
* We do not free the IOASID here in that
* IOMMU driver did not allocate it.
* Unlike native SVM, IOASID for guest use was
* allocated prior to the bind call.
* In any case, if the free call comes before
* the unbind, IOMMU driver will get notified
* and perform cleanup.
*/
ioasid_set_data(pasid, NULL);
kfree(svm);
}
}
}
out:
mutex_unlock(&pasid_mutex);
return ret;
}
static void _load_pasid(void *unused)
{
update_pasid();
}
static void load_pasid(struct mm_struct *mm, u32 pasid)
{
mutex_lock(&mm->context.lock);
/* Synchronize with READ_ONCE in update_pasid(). */
smp_store_release(&mm->pasid, pasid);
/* Update PASID MSR on all CPUs running the mm's tasks. */
on_each_cpu_mask(mm_cpumask(mm), _load_pasid, NULL, true);
mutex_unlock(&mm->context.lock);
}
/* Caller must hold pasid_mutex, mm reference */
static int
intel_svm_bind_mm(struct device *dev, unsigned int flags,
struct svm_dev_ops *ops,
struct mm_struct *mm, struct intel_svm_dev **sd)
{
struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
struct device_domain_info *info;
struct intel_svm_dev *sdev;
struct intel_svm *svm = NULL;
int pasid_max;
int ret;
if (!iommu || dmar_disabled)
return -EINVAL;
if (!intel_svm_capable(iommu))
return -ENOTSUPP;
if (dev_is_pci(dev)) {
pasid_max = pci_max_pasids(to_pci_dev(dev));
if (pasid_max < 0)
return -EINVAL;
} else
pasid_max = 1 << 20;
/* Bind supervisor PASID shuld have mm = NULL */
if (flags & SVM_FLAG_SUPERVISOR_MODE) {
if (!ecap_srs(iommu->ecap) || mm) {
pr_err("Supervisor PASID with user provided mm.\n");
return -EINVAL;
}
}
if (!(flags & SVM_FLAG_PRIVATE_PASID)) {
struct intel_svm *t;
list_for_each_entry(t, &global_svm_list, list) {
if (t->mm != mm || (t->flags & SVM_FLAG_PRIVATE_PASID))
continue;
svm = t;
if (svm->pasid >= pasid_max) {
dev_warn(dev,
"Limited PASID width. Cannot use existing PASID %d\n",
svm->pasid);
ret = -ENOSPC;
goto out;
}
/* Find the matching device in svm list */
for_each_svm_dev(sdev, svm, dev) {
if (sdev->ops != ops) {
ret = -EBUSY;
goto out;
}
sdev->users++;
goto success;
}
break;
}
}
sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);
if (!sdev) {
ret = -ENOMEM;
goto out;
}
sdev->dev = dev;
ret = intel_iommu_enable_pasid(iommu, dev);
if (ret) {
kfree(sdev);
goto out;
}
info = get_domain_info(dev);
sdev->did = FLPT_DEFAULT_DID;
sdev->sid = PCI_DEVID(info->bus, info->devfn);
if (info->ats_enabled) {
sdev->dev_iotlb = 1;
sdev->qdep = info->ats_qdep;
if (sdev->qdep >= QI_DEV_EIOTLB_MAX_INVS)
sdev->qdep = 0;
}
/* Finish the setup now we know we're keeping it */
sdev->users = 1;
sdev->ops = ops;
init_rcu_head(&sdev->rcu);
if (!svm) {
svm = kzalloc(sizeof(*svm), GFP_KERNEL);
if (!svm) {
ret = -ENOMEM;
kfree(sdev);
goto out;
}
svm->iommu = iommu;
if (pasid_max > intel_pasid_max_id)
pasid_max = intel_pasid_max_id;
/* Do not use PASID 0, reserved for RID to PASID */
svm->pasid = ioasid_alloc(NULL, PASID_MIN,
pasid_max - 1, svm);
if (svm->pasid == INVALID_IOASID) {
kfree(svm);
kfree(sdev);
ret = -ENOSPC;
goto out;
}
svm->notifier.ops = &intel_mmuops;
svm->mm = mm;
svm->flags = flags;
INIT_LIST_HEAD_RCU(&svm->devs);
INIT_LIST_HEAD(&svm->list);
ret = -ENOMEM;
if (mm) {
ret = mmu_notifier_register(&svm->notifier, mm);
if (ret) {
ioasid_free(svm->pasid);
kfree(svm);
kfree(sdev);
goto out;
}
}
spin_lock(&iommu->lock);
ret = intel_pasid_setup_first_level(iommu, dev,
mm ? mm->pgd : init_mm.pgd,
svm->pasid, FLPT_DEFAULT_DID,
(mm ? 0 : PASID_FLAG_SUPERVISOR_MODE) |
(cpu_feature_enabled(X86_FEATURE_LA57) ?
PASID_FLAG_FL5LP : 0));
spin_unlock(&iommu->lock);
if (ret) {
if (mm)
mmu_notifier_unregister(&svm->notifier, mm);
ioasid_free(svm->pasid);
kfree(svm);
kfree(sdev);
goto out;
}
list_add_tail(&svm->list, &global_svm_list);
if (mm) {
/* The newly allocated pasid is loaded to the mm. */
load_pasid(mm, svm->pasid);
}
} else {
/*
* Binding a new device with existing PASID, need to setup
* the PASID entry.
*/
spin_lock(&iommu->lock);
ret = intel_pasid_setup_first_level(iommu, dev,
mm ? mm->pgd : init_mm.pgd,
svm->pasid, FLPT_DEFAULT_DID,
(mm ? 0 : PASID_FLAG_SUPERVISOR_MODE) |
(cpu_feature_enabled(X86_FEATURE_LA57) ?
PASID_FLAG_FL5LP : 0));
spin_unlock(&iommu->lock);
if (ret) {
kfree(sdev);
goto out;
}
}
list_add_rcu(&sdev->list, &svm->devs);
success:
sdev->pasid = svm->pasid;
sdev->sva.dev = dev;
if (sd)
*sd = sdev;
ret = 0;
out:
return ret;
}
/* Caller must hold pasid_mutex */
static int intel_svm_unbind_mm(struct device *dev, u32 pasid)
{
struct intel_svm_dev *sdev;
struct intel_iommu *iommu;
struct intel_svm *svm;
int ret = -EINVAL;
iommu = device_to_iommu(dev, NULL, NULL);
if (!iommu)
goto out;
ret = pasid_to_svm_sdev(dev, pasid, &svm, &sdev);
if (ret)
goto out;
if (sdev) {
sdev->users--;
if (!sdev->users) {
list_del_rcu(&sdev->list);
/* Flush the PASID cache and IOTLB for this device.
* Note that we do depend on the hardware *not* using
* the PASID any more. Just as we depend on other
* devices never using PASIDs that they have no right
* to use. We have a *shared* PASID table, because it's
* large and has to be physically contiguous. So it's
* hard to be as defensive as we might like. */
intel_pasid_tear_down_entry(iommu, dev,
svm->pasid, false);
intel_svm_drain_prq(dev, svm->pasid);
kfree_rcu(sdev, rcu);
if (list_empty(&svm->devs)) {
ioasid_free(svm->pasid);
if (svm->mm) {
mmu_notifier_unregister(&svm->notifier, svm->mm);
/* Clear mm's pasid. */
load_pasid(svm->mm, PASID_DISABLED);
}
list_del(&svm->list);
/* We mandate that no page faults may be outstanding
* for the PASID when intel_svm_unbind_mm() is called.
* If that is not obeyed, subtle errors will happen.
* Let's make them less subtle... */
memset(svm, 0x6b, sizeof(*svm));
kfree(svm);
}
}
}
out:
return ret;
}
/* Page request queue descriptor */
struct page_req_dsc {
union {
struct {
u64 type:8;
u64 pasid_present:1;
u64 priv_data_present:1;
u64 rsvd:6;
u64 rid:16;
u64 pasid:20;
u64 exe_req:1;
u64 pm_req:1;
u64 rsvd2:10;
};
u64 qw_0;
};
union {
struct {
u64 rd_req:1;
u64 wr_req:1;
u64 lpig:1;
u64 prg_index:9;
u64 addr:52;
};
u64 qw_1;
};
u64 priv_data[2];
};
#define PRQ_RING_MASK ((0x1000 << PRQ_ORDER) - 0x20)
static bool access_error(struct vm_area_struct *vma, struct page_req_dsc *req)
{
unsigned long requested = 0;
if (req->exe_req)
requested |= VM_EXEC;
if (req->rd_req)
requested |= VM_READ;
if (req->wr_req)
requested |= VM_WRITE;
return (requested & ~vma->vm_flags) != 0;
}
static bool is_canonical_address(u64 addr)
{
int shift = 64 - (__VIRTUAL_MASK_SHIFT + 1);
long saddr = (long) addr;
return (((saddr << shift) >> shift) == saddr);
}
/**
* intel_svm_drain_prq - Drain page requests and responses for a pasid
* @dev: target device
* @pasid: pasid for draining
*
* Drain all pending page requests and responses related to @pasid in both
* software and hardware. This is supposed to be called after the device
* driver has stopped DMA, the pasid entry has been cleared, and both IOTLB
* and DevTLB have been invalidated.
*
* It waits until all pending page requests for @pasid in the page fault
* queue are completed by the prq handling thread. Then follow the steps
* described in VT-d spec CH7.10 to drain all page requests and page
* responses pending in the hardware.
*/
static void intel_svm_drain_prq(struct device *dev, u32 pasid)
{
struct device_domain_info *info;
struct dmar_domain *domain;
struct intel_iommu *iommu;
struct qi_desc desc[3];
struct pci_dev *pdev;
int head, tail;
u16 sid, did;
int qdep;
info = get_domain_info(dev);
if (WARN_ON(!info || !dev_is_pci(dev)))
return;
if (!info->pri_enabled)
return;
iommu = info->iommu;
domain = info->domain;
pdev = to_pci_dev(dev);
sid = PCI_DEVID(info->bus, info->devfn);
did = domain->iommu_did[iommu->seq_id];
qdep = pci_ats_queue_depth(pdev);
/*
* Check and wait until all pending page requests in the queue are
* handled by the prq handling thread.
*/
prq_retry:
reinit_completion(&iommu->prq_complete);
tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK;
head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
while (head != tail) {
struct page_req_dsc *req;
req = &iommu->prq[head / sizeof(*req)];
if (!req->pasid_present || req->pasid != pasid) {
head = (head + sizeof(*req)) & PRQ_RING_MASK;
continue;
}
wait_for_completion(&iommu->prq_complete);
goto prq_retry;
}
/*
* Perform steps described in VT-d spec CH7.10 to drain page
* requests and responses in hardware.
*/
memset(desc, 0, sizeof(desc));
desc[0].qw0 = QI_IWD_STATUS_DATA(QI_DONE) |
QI_IWD_FENCE |
QI_IWD_TYPE;
desc[1].qw0 = QI_EIOTLB_PASID(pasid) |
QI_EIOTLB_DID(did) |
QI_EIOTLB_GRAN(QI_GRAN_NONG_PASID) |
QI_EIOTLB_TYPE;
desc[2].qw0 = QI_DEV_EIOTLB_PASID(pasid) |
QI_DEV_EIOTLB_SID(sid) |
QI_DEV_EIOTLB_QDEP(qdep) |
QI_DEIOTLB_TYPE |
QI_DEV_IOTLB_PFSID(info->pfsid);
qi_retry:
reinit_completion(&iommu->prq_complete);
qi_submit_sync(iommu, desc, 3, QI_OPT_WAIT_DRAIN);
if (readl(iommu->reg + DMAR_PRS_REG) & DMA_PRS_PRO) {
wait_for_completion(&iommu->prq_complete);
goto qi_retry;
}
}
static int prq_to_iommu_prot(struct page_req_dsc *req)
{
int prot = 0;
if (req->rd_req)
prot |= IOMMU_FAULT_PERM_READ;
if (req->wr_req)
prot |= IOMMU_FAULT_PERM_WRITE;
if (req->exe_req)
prot |= IOMMU_FAULT_PERM_EXEC;
if (req->pm_req)
prot |= IOMMU_FAULT_PERM_PRIV;
return prot;
}
static int
intel_svm_prq_report(struct device *dev, struct page_req_dsc *desc)
{
struct iommu_fault_event event;
if (!dev || !dev_is_pci(dev))
return -ENODEV;
/* Fill in event data for device specific processing */
memset(&event, 0, sizeof(struct iommu_fault_event));
event.fault.type = IOMMU_FAULT_PAGE_REQ;
event.fault.prm.addr = desc->addr;
event.fault.prm.pasid = desc->pasid;
event.fault.prm.grpid = desc->prg_index;
event.fault.prm.perm = prq_to_iommu_prot(desc);
if (desc->lpig)
event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE;
if (desc->pasid_present) {
event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
event.fault.prm.flags |= IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID;
}
if (desc->priv_data_present) {
/*
* Set last page in group bit if private data is present,
* page response is required as it does for LPIG.
* iommu_report_device_fault() doesn't understand this vendor
* specific requirement thus we set last_page as a workaround.
*/
event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE;
event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA;
memcpy(event.fault.prm.private_data, desc->priv_data,
sizeof(desc->priv_data));
}
return iommu_report_device_fault(dev, &event);
}
static irqreturn_t prq_event_thread(int irq, void *d)
{
struct intel_svm_dev *sdev = NULL;
struct intel_iommu *iommu = d;
struct intel_svm *svm = NULL;
int head, tail, handled = 0;
/* Clear PPR bit before reading head/tail registers, to
* ensure that we get a new interrupt if needed. */
writel(DMA_PRS_PPR, iommu->reg + DMAR_PRS_REG);
tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK;
head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
while (head != tail) {
struct vm_area_struct *vma;
struct page_req_dsc *req;
struct qi_desc resp;
int result;
vm_fault_t ret;
u64 address;
handled = 1;
req = &iommu->prq[head / sizeof(*req)];
result = QI_RESP_FAILURE;
address = (u64)req->addr << VTD_PAGE_SHIFT;
if (!req->pasid_present) {
pr_err("%s: Page request without PASID: %08llx %08llx\n",
iommu->name, ((unsigned long long *)req)[0],
((unsigned long long *)req)[1]);
goto no_pasid;
}
if (!svm || svm->pasid != req->pasid) {
rcu_read_lock();
svm = ioasid_find(NULL, req->pasid, NULL);
/* It *can't* go away, because the driver is not permitted
* to unbind the mm while any page faults are outstanding.
* So we only need RCU to protect the internal idr code. */
rcu_read_unlock();
if (IS_ERR_OR_NULL(svm)) {
pr_err("%s: Page request for invalid PASID %d: %08llx %08llx\n",
iommu->name, req->pasid, ((unsigned long long *)req)[0],
((unsigned long long *)req)[1]);
goto no_pasid;
}
}
if (!sdev || sdev->sid != req->rid) {
struct intel_svm_dev *t;
sdev = NULL;
rcu_read_lock();
list_for_each_entry_rcu(t, &svm->devs, list) {
if (t->sid == req->rid) {
sdev = t;
break;
}
}
rcu_read_unlock();
}
result = QI_RESP_INVALID;
/* Since we're using init_mm.pgd directly, we should never take
* any faults on kernel addresses. */
if (!svm->mm)
goto bad_req;
/* If address is not canonical, return invalid response */
if (!is_canonical_address(address))
goto bad_req;
/*
* If prq is to be handled outside iommu driver via receiver of
* the fault notifiers, we skip the page response here.
*/
if (svm->flags & SVM_FLAG_GUEST_MODE) {
if (sdev && !intel_svm_prq_report(sdev->dev, req))
goto prq_advance;
else
goto bad_req;
}
/* If the mm is already defunct, don't handle faults. */
if (!mmget_not_zero(svm->mm))
goto bad_req;
mmap_read_lock(svm->mm);
vma = find_extend_vma(svm->mm, address);
if (!vma || address < vma->vm_start)
goto invalid;
if (access_error(vma, req))
goto invalid;
ret = handle_mm_fault(vma, address,
req->wr_req ? FAULT_FLAG_WRITE : 0,
NULL);
if (ret & VM_FAULT_ERROR)
goto invalid;
result = QI_RESP_SUCCESS;
invalid:
mmap_read_unlock(svm->mm);
mmput(svm->mm);
bad_req:
WARN_ON(!sdev);
if (sdev && sdev->ops && sdev->ops->fault_cb) {
int rwxp = (req->rd_req << 3) | (req->wr_req << 2) |
(req->exe_req << 1) | (req->pm_req);
sdev->ops->fault_cb(sdev->dev, req->pasid, req->addr,
req->priv_data, rwxp, result);
}
/* We get here in the error case where the PASID lookup failed,
and these can be NULL. Do not use them below this point! */
sdev = NULL;
svm = NULL;
no_pasid:
if (req->lpig || req->priv_data_present) {
/*
* Per VT-d spec. v3.0 ch7.7, system software must
* respond with page group response if private data
* is present (PDP) or last page in group (LPIG) bit
* is set. This is an additional VT-d feature beyond
* PCI ATS spec.
*/
resp.qw0 = QI_PGRP_PASID(req->pasid) |
QI_PGRP_DID(req->rid) |
QI_PGRP_PASID_P(req->pasid_present) |
QI_PGRP_PDP(req->priv_data_present) |
QI_PGRP_RESP_CODE(result) |
QI_PGRP_RESP_TYPE;
resp.qw1 = QI_PGRP_IDX(req->prg_index) |
QI_PGRP_LPIG(req->lpig);
if (req->priv_data_present)
memcpy(&resp.qw2, req->priv_data,
sizeof(req->priv_data));
resp.qw2 = 0;
resp.qw3 = 0;
qi_submit_sync(iommu, &resp, 1, 0);
}
prq_advance:
head = (head + sizeof(*req)) & PRQ_RING_MASK;
}
dmar_writeq(iommu->reg + DMAR_PQH_REG, tail);
/*
* Clear the page request overflow bit and wake up all threads that
* are waiting for the completion of this handling.
*/
if (readl(iommu->reg + DMAR_PRS_REG) & DMA_PRS_PRO)
writel(DMA_PRS_PRO, iommu->reg + DMAR_PRS_REG);
if (!completion_done(&iommu->prq_complete))
complete(&iommu->prq_complete);
return IRQ_RETVAL(handled);
}
#define to_intel_svm_dev(handle) container_of(handle, struct intel_svm_dev, sva)
struct iommu_sva *
intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
{
struct iommu_sva *sva = ERR_PTR(-EINVAL);
struct intel_svm_dev *sdev = NULL;
unsigned int flags = 0;
int ret;
/*
* TODO: Consolidate with generic iommu-sva bind after it is merged.
* It will require shared SVM data structures, i.e. combine io_mm
* and intel_svm etc.
*/
if (drvdata)
flags = *(unsigned int *)drvdata;
mutex_lock(&pasid_mutex);
ret = intel_svm_bind_mm(dev, flags, NULL, mm, &sdev);
if (ret)
sva = ERR_PTR(ret);
else if (sdev)
sva = &sdev->sva;
else
WARN(!sdev, "SVM bind succeeded with no sdev!\n");
mutex_unlock(&pasid_mutex);
return sva;
}
void intel_svm_unbind(struct iommu_sva *sva)
{
struct intel_svm_dev *sdev;
mutex_lock(&pasid_mutex);
sdev = to_intel_svm_dev(sva);
intel_svm_unbind_mm(sdev->dev, sdev->pasid);
mutex_unlock(&pasid_mutex);
}
u32 intel_svm_get_pasid(struct iommu_sva *sva)
{
struct intel_svm_dev *sdev;
u32 pasid;
mutex_lock(&pasid_mutex);
sdev = to_intel_svm_dev(sva);
pasid = sdev->pasid;
mutex_unlock(&pasid_mutex);
return pasid;
}
int intel_svm_page_response(struct device *dev,
struct iommu_fault_event *evt,
struct iommu_page_response *msg)
{
struct iommu_fault_page_request *prm;
struct intel_svm_dev *sdev = NULL;
struct intel_svm *svm = NULL;
struct intel_iommu *iommu;
bool private_present;
bool pasid_present;
bool last_page;
u8 bus, devfn;
int ret = 0;
u16 sid;
if (!dev || !dev_is_pci(dev))
return -ENODEV;
iommu = device_to_iommu(dev, &bus, &devfn);
if (!iommu)
return -ENODEV;
if (!msg || !evt)
return -EINVAL;
mutex_lock(&pasid_mutex);
prm = &evt->fault.prm;
sid = PCI_DEVID(bus, devfn);
pasid_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
private_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA;
last_page = prm->flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE;
if (!pasid_present) {
ret = -EINVAL;
goto out;
}
if (prm->pasid == 0 || prm->pasid >= PASID_MAX) {
ret = -EINVAL;
goto out;
}
ret = pasid_to_svm_sdev(dev, prm->pasid, &svm, &sdev);
if (ret || !sdev) {
ret = -ENODEV;
goto out;
}
/*
* For responses from userspace, need to make sure that the
* pasid has been bound to its mm.
*/
if (svm->flags & SVM_FLAG_GUEST_MODE) {
struct mm_struct *mm;
mm = get_task_mm(current);
if (!mm) {
ret = -EINVAL;
goto out;
}
if (mm != svm->mm) {
ret = -ENODEV;
mmput(mm);
goto out;
}
mmput(mm);
}
/*
* Per VT-d spec. v3.0 ch7.7, system software must respond
* with page group response if private data is present (PDP)
* or last page in group (LPIG) bit is set. This is an
* additional VT-d requirement beyond PCI ATS spec.
*/
if (last_page || private_present) {
struct qi_desc desc;
desc.qw0 = QI_PGRP_PASID(prm->pasid) | QI_PGRP_DID(sid) |
QI_PGRP_PASID_P(pasid_present) |
QI_PGRP_PDP(private_present) |
QI_PGRP_RESP_CODE(msg->code) |
QI_PGRP_RESP_TYPE;
desc.qw1 = QI_PGRP_IDX(prm->grpid) | QI_PGRP_LPIG(last_page);
desc.qw2 = 0;
desc.qw3 = 0;
if (private_present)
memcpy(&desc.qw2, prm->private_data,
sizeof(prm->private_data));
qi_submit_sync(iommu, &desc, 1, 0);
}
out:
mutex_unlock(&pasid_mutex);
return ret;
}
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