[PATCH AUTOSEL 5.15 22/24] drm/amdkfd: process_info lock not needed for svm

Sasha Levin
2021-12-06T21:15:38Z

From: Philip Yang <Philip.Yang@amd.com>

[ Upstream commit 3abfe30d803e62cc75dec254eefab3b04d69219b ]

process_info->lock is used to protect kfd_bo_list, vm_list_head, n_vms
and userptr valid/inval list, svm_range_restore_work and
svm_range_set_attr don't access those, so do not need to take
process_info lock. This will avoid potential circular locking issue.

Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 9 ---------
1 file changed, 9 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 179080329af89..5a674235ae41a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1565,7 +1565,6 @@ svm_range_list_lock_and_flush_work(struct svm_range_list *svms,
static void svm_range_restore_work(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
- struct amdkfd_process_info *process_info;
struct svm_range_list *svms;
struct svm_range *prange;
struct kfd_process *p;
@@ -1585,12 +1584,10 @@ static void svm_range_restore_work(struct work_struct *work)
* the lifetime of this thread, kfd_process and mm will be valid.
*/
p = container_of(svms, struct kfd_process, svms);
- process_info = p->kgd_process_info;
mm = p->mm;
if (!mm)
return;

- mutex_lock(&process_info->lock);
svm_range_list_lock_and_flush_work(svms, mm);
mutex_lock(&svms->lock);

@@ -1643,7 +1640,6 @@ static void svm_range_restore_work(struct work_struct *work)
out_reschedule:
mutex_unlock(&svms->lock);
mmap_write_unlock(mm);
- mutex_unlock(&process_info->lock);

/* If validation failed, reschedule another attempt */
if (evicted_ranges) {
@@ -2974,7 +2970,6 @@ static int
svm_range_set_attr(struct kfd_process *p, uint64_t start, uint64_t size,
uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
{
- struct amdkfd_process_info *process_info = p->kgd_process_info;
struct mm_struct *mm = current->mm;
struct list_head update_list;
struct list_head insert_list;
@@ -2993,8 +2988,6 @@ svm_range_set_attr(struct kfd_process *p, uint64_t start, uint64_t size,

svms = &p->svms;

- mutex_lock(&process_info->lock);
-
svm_range_list_lock_and_flush_work(svms, mm);

if (!svm_range_is_valid(mm, start, size)) {
@@ -3070,8 +3063,6 @@ svm_range_set_attr(struct kfd_process *p, uint64_t start, uint64_t size,
mutex_unlock(&svms->lock);
mmap_read_unlock(mm);
out:
- mutex_unlock(&process_info->lock);
-
pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] done, r=%d\n", p->pasid,
&p->svms, start, start + size - 1, r);

--
2.33.0