drm/amdkfd: track unified memory reservation with xnack off

[WHY]
Unified memory with xnack off should be tracked, as userptr mappings
and legacy allocations do. To avoid oversuscribe system memory when
xnack off.
[How]
Exposing functions reserve_mem_limit and unreserve_mem_limit to SVM
API and call them on every prange creation and free.

Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 14 insertions, 9 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 08997092e7f7..1d4982471f8d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -129,7 +129,7 @@ void amdgpu_amdkfd_reserve_system_mem(uint64_t size)
  *
  * Return: returns -ENOMEM in case of error, ZERO otherwise
  */
-static int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device *adev,
+int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device *adev,
 		uint64_t size, u32 alloc_flag)
 {
 	uint64_t reserved_for_pt =
@@ -169,7 +169,7 @@ static int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device *adev,
 	     kfd_mem_limit.max_system_mem_limit && !no_system_mem_limit) ||
 	    (kfd_mem_limit.ttm_mem_used + ttm_mem_needed >
 	     kfd_mem_limit.max_ttm_mem_limit) ||
-	    (adev->kfd.vram_used + vram_needed >
+	    (adev && adev->kfd.vram_used + vram_needed >
 	     adev->gmc.real_vram_size -
 	     atomic64_read(&adev->vram_pin_size) -
 	     reserved_for_pt)) {
@@ -180,7 +180,10 @@ static int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device *adev,
 	/* Update memory accounting by decreasing available system
 	 * memory, TTM memory and GPU memory as computed above
 	 */
-	adev->kfd.vram_used += vram_needed;
+	WARN_ONCE(vram_needed && !adev,
+		  "adev reference can't be null when vram is used");
+	if (adev)
+		adev->kfd.vram_used += vram_needed;
 	kfd_mem_limit.system_mem_used += system_mem_needed;
 	kfd_mem_limit.ttm_mem_used += ttm_mem_needed;
 
@@ -189,7 +192,7 @@ release:
 	return ret;
 }
 
-static void unreserve_mem_limit(struct amdgpu_device *adev,
+void amdgpu_amdkfd_unreserve_mem_limit(struct amdgpu_device *adev,
 		uint64_t size, u32 alloc_flag)
 {
 	spin_lock(&kfd_mem_limit.mem_limit_lock);
@@ -198,7 +201,10 @@ static void unreserve_mem_limit(struct amdgpu_device *adev,
 		kfd_mem_limit.system_mem_used -= size;
 		kfd_mem_limit.ttm_mem_used -= size;
 	} else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_VRAM) {
-		adev->kfd.vram_used -= ALIGN(size, VRAM_ALLOCATION_ALIGN);
+		WARN_ONCE(!adev,
+			  "adev reference can't be null when alloc mem flags vram is set");
+		if (adev)
+			adev->kfd.vram_used -= ALIGN(size, VRAM_ALLOCATION_ALIGN);
 	} else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR) {
 		kfd_mem_limit.system_mem_used -= size;
 	} else if (!(alloc_flag &
@@ -207,8 +213,7 @@ static void unreserve_mem_limit(struct amdgpu_device *adev,
 		pr_err("%s: Invalid BO type %#x\n", __func__, alloc_flag);
 		goto release;
 	}
-
-	WARN_ONCE(adev->kfd.vram_used < 0,
+	WARN_ONCE(adev && adev->kfd.vram_used < 0,
 		  "KFD VRAM memory accounting unbalanced");
 	WARN_ONCE(kfd_mem_limit.ttm_mem_used < 0,
 		  "KFD TTM memory accounting unbalanced");
@@ -225,7 +230,7 @@ void amdgpu_amdkfd_release_notify(struct amdgpu_bo *bo)
 	u32 alloc_flags = bo->kfd_bo->alloc_flags;
 	u64 size = amdgpu_bo_size(bo);
 
-	unreserve_mem_limit(adev, size, alloc_flags);
+	amdgpu_amdkfd_unreserve_mem_limit(adev, size, alloc_flags);
 
 	kfree(bo->kfd_bo);
 }
@@ -1749,7 +1754,7 @@ err_node_allow:
 	/* Don't unreserve system mem limit twice */
 	goto err_reserve_limit;
 err_bo_create:
-	unreserve_mem_limit(adev, size, flags);
+	amdgpu_amdkfd_unreserve_mem_limit(adev, size, flags);
 err_reserve_limit:
 	mutex_destroy(&(*mem)->lock);
 	if (gobj)