[PATCH 3/3] drm/amdgpu: generally allow over-commit during BO allocation

[Christian König]

We already fallback to a dummy BO with no backing store when we
allocate GDS,GWS and OA resources and to GTT when we allocate VRAM.

Drop all those workarounds and generalize this for GTT as well. This
fixes ENOMEM issues with runaway applications which try to allocate/free
GTT in a loop and are otherwise only limited by the CPU speed.

The CS will wait for the cleanup of freed up BOs to satisfy the
various domain specific limits and so effectively throttle those
buggy applications down to a sane allocation behavior again.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c    | 16 +++-------------
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c |  6 +-----
 2 files changed, 4 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 8ef31d687ef3..286509e5e17e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -112,7 +112,7 @@ int amdgpu_gem_object_create(struct amdgpu_device *adev, unsigned long size,
 	bp.resv = resv;
 	bp.preferred_domain = initial_domain;
 	bp.flags = flags;
-	bp.domain = initial_domain;
+	bp.domain = initial_domain | AMDGPU_GEM_DOMAIN_CPU;
 	bp.bo_ptr_size = sizeof(struct amdgpu_bo);
 
 	r = amdgpu_bo_create_user(adev, &bp, &ubo);
@@ -331,20 +331,10 @@ int amdgpu_gem_create_ioctl(struct drm_device *dev, void *data,
 	}
 
 	initial_domain = (u32)(0xffffffff & args->in.domains);
-retry:
 	r = amdgpu_gem_object_create(adev, size, args->in.alignment,
-				     initial_domain,
-				     flags, ttm_bo_type_device, resv, &gobj);
+				     initial_domain, flags, ttm_bo_type_device,
+				     resv, &gobj);
 	if (r && r != -ERESTARTSYS) {
-		if (flags & AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED) {
-			flags &= ~AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
-			goto retry;
-		}
-
-		if (initial_domain == AMDGPU_GEM_DOMAIN_VRAM) {
-			initial_domain |= AMDGPU_GEM_DOMAIN_GTT;
-			goto retry;
-		}
 		DRM_DEBUG("Failed to allocate GEM object (%llu, %d, %llu, %d)\n",
 				size, initial_domain, args->in.alignment, r);
 	}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 974e85d8b6cc..919bbea2e3ac 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -581,11 +581,7 @@ int amdgpu_bo_create(struct amdgpu_device *adev,
 		bo->flags |= AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE;
 
 	bo->tbo.bdev = &adev->mman.bdev;
-	if (bp->domain & (AMDGPU_GEM_DOMAIN_GWS | AMDGPU_GEM_DOMAIN_OA |
-			  AMDGPU_GEM_DOMAIN_GDS))
-		amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_CPU);
-	else
-		amdgpu_bo_placement_from_domain(bo, bp->domain);
+	amdgpu_bo_placement_from_domain(bo, bp->domain);
 	if (bp->type == ttm_bo_type_kernel)
 		bo->tbo.priority = 1;
 
-- 
2.34.1