hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

iommu/ioasid: Add ioasid references 

Let IOASID users take references to existing ioasids with ioasid_get().
ioasid_put() drops a reference and only frees the ioasid when its
reference number is zero. It returns true if the ioasid was freed.
For drivers that don't call ioasid_get(), ioasid_put() is the same as
ioasid_free().

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20201106155048.997886-2-jean-philippe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Jean-Philippe Brucker 2020-11-06 16:50:47 +01:00 committed by Will Deacon
parent f8394f232b
commit cb4789b0d1
4 changed files with 48 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/iommu/intel/iommu.c
View File

@ -5198,7 +5198,7 @@ static void auxiliary_unlink_device(struct dmar_domain *domain,
domain->auxd_refcnt--;
if (!domain->auxd_refcnt && domain->default_pasid > 0)
ioasid_free(domain->default_pasid);
ioasid_put(domain->default_pasid);
}
static int aux_domain_add_dev(struct dmar_domain *domain,
@ -5259,7 +5259,7 @@ attach_failed:
spin_unlock(&iommu->lock);
spin_unlock_irqrestore(&device_domain_lock, flags);
if (!domain->auxd_refcnt && domain->default_pasid > 0)
ioasid_free(domain->default_pasid);
ioasid_put(domain->default_pasid);
return ret;
}

6
drivers/iommu/intel/svm.c
View File

@ -598,7 +598,7 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
if (mm) {
ret = mmu_notifier_register(&svm->notifier, mm);
if (ret) {
ioasid_free(svm->pasid);
ioasid_put(svm->pasid);
kfree(svm);
kfree(sdev);
goto out;
@ -616,7 +616,7 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
if (ret) {
if (mm)
mmu_notifier_unregister(&svm->notifier, mm);
ioasid_free(svm->pasid);
ioasid_put(svm->pasid);
kfree(svm);
kfree(sdev);
goto out;
@ -689,7 +689,7 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid)
kfree_rcu(sdev, rcu);
if (list_empty(&svm->devs)) {
ioasid_free(svm->pasid);
ioasid_put(svm->pasid);
if (svm->mm) {
mmu_notifier_unregister(&svm->notifier, svm->mm);
/* Clear mm's pasid. */

40
drivers/iommu/ioasid.c
View File

@ -2,7 +2,7 @@
/*
* I/O Address Space ID allocator. There is one global IOASID space, split into
* subsets. Users create a subset with DECLARE_IOASID_SET, then allocate and
* free IOASIDs with ioasid_alloc and ioasid_free.
* free IOASIDs with ioasid_alloc and ioasid_put.
*/
#include <linux/ioasid.h>
#include <linux/module.h>
@ -15,6 +15,7 @@ struct ioasid_data {
struct ioasid_set *set;
void *private;
struct rcu_head rcu;
refcount_t refs;
};
/*
@ -314,6 +315,7 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
data->set = set;
data->private = private;
refcount_set(&data->refs, 1);
/*
* Custom allocator needs allocator data to perform platform specific
@ -346,13 +348,36 @@ exit_free:
EXPORT_SYMBOL_GPL(ioasid_alloc);
/**
* ioasid_free - Free an IOASID
* @ioasid: the ID to remove
* ioasid_get - obtain a reference to the IOASID
*/
void ioasid_free(ioasid_t ioasid)
void ioasid_get(ioasid_t ioasid)
{
struct ioasid_data *ioasid_data;
spin_lock(&ioasid_allocator_lock);
ioasid_data = xa_load(&active_allocator->xa, ioasid);
if (ioasid_data)
refcount_inc(&ioasid_data->refs);
else
WARN_ON(1);
spin_unlock(&ioasid_allocator_lock);
}
EXPORT_SYMBOL_GPL(ioasid_get);
/**
* ioasid_put - Release a reference to an ioasid
* @ioasid: the ID to remove
*
* Put a reference to the IOASID, free it when the number of references drops to
* zero.
*
* Return: %true if the IOASID was freed, %false otherwise.
*/
bool ioasid_put(ioasid_t ioasid)
{
bool free = false;
struct ioasid_data *ioasid_data;
spin_lock(&ioasid_allocator_lock);
ioasid_data = xa_load(&active_allocator->xa, ioasid);
if (!ioasid_data) {
@ -360,6 +385,10 @@ void ioasid_free(ioasid_t ioasid)
goto exit_unlock;
}
free = refcount_dec_and_test(&ioasid_data->refs);
if (!free)
goto exit_unlock;
active_allocator->ops->free(ioasid, active_allocator->ops->pdata);
/* Custom allocator needs additional steps to free the xa element */
if (active_allocator->flags & IOASID_ALLOCATOR_CUSTOM) {
@ -369,8 +398,9 @@ void ioasid_free(ioasid_t ioasid)
exit_unlock:
spin_unlock(&ioasid_allocator_lock);
return free;
}
EXPORT_SYMBOL_GPL(ioasid_free);
EXPORT_SYMBOL_GPL(ioasid_put);
/**
* ioasid_find - Find IOASID data

10
include/linux/ioasid.h
View File

@ -34,7 +34,8 @@ struct ioasid_allocator_ops {
#if IS_ENABLED(CONFIG_IOASID)
ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
void *private);
void ioasid_free(ioasid_t ioasid);
void ioasid_get(ioasid_t ioasid);
bool ioasid_put(ioasid_t ioasid);
void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
bool (*getter)(void *));
int ioasid_register_allocator(struct ioasid_allocator_ops *allocator);
@ -48,10 +49,15 @@ static inline ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min,
return INVALID_IOASID;
}
static inline void ioasid_free(ioasid_t ioasid)
static inline void ioasid_get(ioasid_t ioasid)
{
}
static inline bool ioasid_put(ioasid_t ioasid)
{
return false;
}
static inline void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
bool (*getter)(void *))
{