4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michel Dänzer <[email protected]>

commit a5ccfe5c20740f2fbf00291490cdf8d2373ec255 upstream.

Concurrent execution of the non-atomic arithmetic could result in
completely bogus values.

v2:
* Rebased on v2 of the previous patch

Cc: [email protected]
Bugzilla: https://bugs.freedesktop.org/106872
Reviewed-by: Christian König <[email protected]>
Signed-off-by: Michel Dänzer <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h        |    6 +++---
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c     |    2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c    |   22 +++++++++++-----------
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c |   14 ++++++++------
 4 files changed, 23 insertions(+), 21 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1579,9 +1579,9 @@ struct amdgpu_device {
        DECLARE_HASHTABLE(mn_hash, 7);
 
        /* tracking pinned memory */
-       u64 vram_pin_size;
-       u64 visible_pin_size;
-       u64 gart_pin_size;
+       atomic64_t vram_pin_size;
+       atomic64_t visible_pin_size;
+       atomic64_t gart_pin_size;
 
        /* amdkfd interface */
        struct kfd_dev          *kfd;
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -257,7 +257,7 @@ static void amdgpu_cs_get_threshold_for_
                return;
        }
 
-       total_vram = adev->gmc.real_vram_size - adev->vram_pin_size;
+       total_vram = adev->gmc.real_vram_size - 
atomic64_read(&adev->vram_pin_size);
        used_vram = amdgpu_vram_mgr_usage(&adev->mman.bdev.man[TTM_PL_VRAM]);
        free_vram = used_vram >= total_vram ? 0 : total_vram - used_vram;
 
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -494,13 +494,13 @@ static int amdgpu_info_ioctl(struct drm_
        case AMDGPU_INFO_VRAM_GTT: {
                struct drm_amdgpu_info_vram_gtt vram_gtt;
 
-               vram_gtt.vram_size = adev->gmc.real_vram_size;
-               vram_gtt.vram_size -= adev->vram_pin_size;
-               vram_gtt.vram_cpu_accessible_size = adev->gmc.visible_vram_size;
-               vram_gtt.vram_cpu_accessible_size -= adev->visible_pin_size;
+               vram_gtt.vram_size = adev->gmc.real_vram_size -
+                       atomic64_read(&adev->vram_pin_size);
+               vram_gtt.vram_cpu_accessible_size = adev->gmc.visible_vram_size 
-
+                       atomic64_read(&adev->visible_pin_size);
                vram_gtt.gtt_size = adev->mman.bdev.man[TTM_PL_TT].size;
                vram_gtt.gtt_size *= PAGE_SIZE;
-               vram_gtt.gtt_size -= adev->gart_pin_size;
+               vram_gtt.gtt_size -= atomic64_read(&adev->gart_pin_size);
                return copy_to_user(out, &vram_gtt,
                                    min((size_t)size, sizeof(vram_gtt))) ? 
-EFAULT : 0;
        }
@@ -509,16 +509,16 @@ static int amdgpu_info_ioctl(struct drm_
 
                memset(&mem, 0, sizeof(mem));
                mem.vram.total_heap_size = adev->gmc.real_vram_size;
-               mem.vram.usable_heap_size =
-                       adev->gmc.real_vram_size - adev->vram_pin_size;
+               mem.vram.usable_heap_size = adev->gmc.real_vram_size -
+                       atomic64_read(&adev->vram_pin_size);
                mem.vram.heap_usage =
                        
amdgpu_vram_mgr_usage(&adev->mman.bdev.man[TTM_PL_VRAM]);
                mem.vram.max_allocation = mem.vram.usable_heap_size * 3 / 4;
 
                mem.cpu_accessible_vram.total_heap_size =
                        adev->gmc.visible_vram_size;
-               mem.cpu_accessible_vram.usable_heap_size =
-                       adev->gmc.visible_vram_size - adev->visible_pin_size;
+               mem.cpu_accessible_vram.usable_heap_size = 
adev->gmc.visible_vram_size -
+                       atomic64_read(&adev->visible_pin_size);
                mem.cpu_accessible_vram.heap_usage =
                        
amdgpu_vram_mgr_vis_usage(&adev->mman.bdev.man[TTM_PL_VRAM]);
                mem.cpu_accessible_vram.max_allocation =
@@ -526,8 +526,8 @@ static int amdgpu_info_ioctl(struct drm_
 
                mem.gtt.total_heap_size = adev->mman.bdev.man[TTM_PL_TT].size;
                mem.gtt.total_heap_size *= PAGE_SIZE;
-               mem.gtt.usable_heap_size = mem.gtt.total_heap_size
-                       - adev->gart_pin_size;
+               mem.gtt.usable_heap_size = mem.gtt.total_heap_size -
+                       atomic64_read(&adev->gart_pin_size);
                mem.gtt.heap_usage =
                        amdgpu_gtt_mgr_usage(&adev->mman.bdev.man[TTM_PL_TT]);
                mem.gtt.max_allocation = mem.gtt.usable_heap_size * 3 / 4;
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -761,10 +761,11 @@ int amdgpu_bo_pin_restricted(struct amdg
 
        domain = amdgpu_mem_type_to_domain(bo->tbo.mem.mem_type);
        if (domain == AMDGPU_GEM_DOMAIN_VRAM) {
-               adev->vram_pin_size += amdgpu_bo_size(bo);
-               adev->visible_pin_size += amdgpu_vram_mgr_bo_visible_size(bo);
+               atomic64_add(amdgpu_bo_size(bo), &adev->vram_pin_size);
+               atomic64_add(amdgpu_vram_mgr_bo_visible_size(bo),
+                            &adev->visible_pin_size);
        } else if (domain == AMDGPU_GEM_DOMAIN_GTT) {
-               adev->gart_pin_size += amdgpu_bo_size(bo);
+               atomic64_add(amdgpu_bo_size(bo), &adev->gart_pin_size);
        }
 
 error:
@@ -791,10 +792,11 @@ int amdgpu_bo_unpin(struct amdgpu_bo *bo
                return 0;
 
        if (bo->tbo.mem.mem_type == TTM_PL_VRAM) {
-               adev->vram_pin_size -= amdgpu_bo_size(bo);
-               adev->visible_pin_size -= amdgpu_vram_mgr_bo_visible_size(bo);
+               atomic64_sub(amdgpu_bo_size(bo), &adev->vram_pin_size);
+               atomic64_sub(amdgpu_vram_mgr_bo_visible_size(bo),
+                            &adev->visible_pin_size);
        } else if (bo->tbo.mem.mem_type == TTM_PL_TT) {
-               adev->gart_pin_size -= amdgpu_bo_size(bo);
+               atomic64_sub(amdgpu_bo_size(bo), &adev->gart_pin_size);
        }
 
        for (i = 0; i < bo->placement.num_placement; i++) {


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