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From 95d5c092f00e9a020a951392d07a846aea6193a0 Mon Sep 17 00:00:00 2001
From: Felix Kuehling <Felix.Kuehling@amd.com>
Date: Tue, 21 Mar 2017 12:05:18 -0400
Subject: [PATCH 1641/4131] drm/amdgpu: Simplify process termination in
amdgpu_ttm_tt_get_user_pages
Most of this is taken care of by the new userptr restore worker by
holding task and mm references when calling amdgpu_ttm_tt_get_user_pages.
Change-Id: I0075e5ff997b7bc65f164e6d8bf84d43eb734092
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 33 ++++++++++-----------------------
1 file changed, 10 insertions(+), 23 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index c4b1c9d..af526a8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -666,8 +666,7 @@ struct amdgpu_ttm_tt {
struct amdgpu_device *adev;
u64 offset;
uint64_t userptr;
- struct mm_struct *usermm;
- struct pid *userpid;
+ struct task_struct *usertask;
uint32_t userflags;
spinlock_t guptasklock;
struct list_head guptasks;
@@ -679,11 +678,14 @@ struct amdgpu_ttm_tt {
int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)
{
struct amdgpu_ttm_tt *gtt = (void *)ttm;
+ struct mm_struct *mm = gtt->usertask->mm;
unsigned int flags = 0;
unsigned pinned = 0;
- struct task_struct *usertask;
int r;
+ if (!mm) /* Happens during process shutdown */
+ return -ESRCH;
+
if (!(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY))
flags |= FOLL_WRITE;
@@ -693,22 +695,11 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)
unsigned long end = gtt->userptr + ttm->num_pages * PAGE_SIZE;
struct vm_area_struct *vma;
- vma = find_vma(gtt->usermm, gtt->userptr);
+ vma = find_vma(mm, gtt->userptr);
if (!vma || vma->vm_file || vma->vm_end < end)
return -EPERM;
}
- if (!gtt->userpid)
- return -EINVAL;
- usertask = get_pid_task(gtt->userpid, PIDTYPE_PID);
- if (!usertask)
- return -ESRCH;
- if (usertask->mm != gtt->usermm) {
- /* Happens during process shutdown */
- put_task_struct(usertask);
- return -ESRCH;
- }
-
do {
unsigned num_pages = ttm->num_pages - pinned;
uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE;
@@ -733,12 +724,10 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)
} while (pinned < ttm->num_pages);
- put_task_struct(usertask);
return 0;
release_pages:
release_pages(pages, pinned, 0);
- put_task_struct(usertask);
return r;
}
@@ -991,9 +980,6 @@ static void amdgpu_ttm_backend_destroy(struct ttm_tt *ttm)
{
struct amdgpu_ttm_tt *gtt = (void *)ttm;
- if (gtt->userpid)
- put_pid(gtt->userpid);
-
ttm_dma_tt_fini(>t->ttm);
kfree(gtt);
}
@@ -1095,8 +1081,6 @@ int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
gtt->userptr = addr;
gtt->usertask = current->group_leader;
- gtt->usermm = current->mm;
- gtt->userpid = get_task_pid(current->group_leader, PIDTYPE_PID);
gtt->userflags = flags;
spin_lock_init(>t->guptasklock);
INIT_LIST_HEAD(>t->guptasks);
@@ -1113,7 +1097,10 @@ struct mm_struct *amdgpu_ttm_tt_get_usermm(struct ttm_tt *ttm)
if (gtt == NULL)
return NULL;
- return gtt->usermm;
+ if (gtt->usertask == NULL)
+ return NULL;
+
+ return gtt->usertask->mm;
}
bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
--
2.7.4
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