drm/amdgpu: fix VA hole handling on Vega10 v3

Similar to the CPU address space the VA on Vega10 has a hole in it.

v2: use dev_dbg instead of dev_err
v3: add some more comments to explain how the hw works

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
CC: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c

@@ -870,8 +870,8 @@ static int amdgpu_cs_ib_vm_chunk(struct amdgpu_device *adev,
 			struct amdgpu_bo_va_mapping *m;
 			struct amdgpu_bo *aobj = NULL;
 			struct amdgpu_cs_chunk *chunk;
+			uint64_t offset, va_start;
 			struct amdgpu_ib *ib;
-			uint64_t offset;
 			uint8_t *kptr;
 
 			chunk = &p->chunks[i];
@@ -881,14 +881,14 @@ static int amdgpu_cs_ib_vm_chunk(struct amdgpu_device *adev,
 			if (chunk->chunk_id != AMDGPU_CHUNK_ID_IB)
 				continue;
 
-			r = amdgpu_cs_find_mapping(p, chunk_ib->va_start,
-						   &aobj, &m);
+			va_start = chunk_ib->va_start & AMDGPU_VA_HOLE_MASK;
+			r = amdgpu_cs_find_mapping(p, va_start, &aobj, &m);
 			if (r) {
 				DRM_ERROR("IB va_start is invalid\n");
 				return r;
 			}
 
-			if ((chunk_ib->va_start + chunk_ib->ib_bytes) >
+			if ((va_start + chunk_ib->ib_bytes) >
 			    (m->last + 1) * AMDGPU_GPU_PAGE_SIZE) {
 				DRM_ERROR("IB va_start+ib_bytes is invalid\n");
 				return -EINVAL;
@@ -901,7 +901,7 @@ static int amdgpu_cs_ib_vm_chunk(struct amdgpu_device *adev,
 			}
 
 			offset = m->start * AMDGPU_GPU_PAGE_SIZE;
-			kptr += chunk_ib->va_start - offset;
+			kptr += va_start - offset;
 
 			memcpy(ib->ptr, kptr, chunk_ib->ib_bytes);
 			amdgpu_bo_kunmap(aobj);

drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c

@@ -564,6 +564,17 @@ int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
 		return -EINVAL;
 	}
 
+	if (args->va_address >= AMDGPU_VA_HOLE_START &&
+	    args->va_address < AMDGPU_VA_HOLE_END) {
+		dev_dbg(&dev->pdev->dev,
+			"va_address 0x%LX is in VA hole 0x%LX-0x%LX\n",
+			args->va_address, AMDGPU_VA_HOLE_START,
+			AMDGPU_VA_HOLE_END);
+		return -EINVAL;
+	}
+
+	args->va_address &= AMDGPU_VA_HOLE_MASK;
+
 	if ((args->flags & ~valid_flags) && (args->flags & ~prt_flags)) {
 		dev_err(&dev->pdev->dev, "invalid flags combination 0x%08X\n",
 			args->flags);

drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c

@@ -578,7 +578,9 @@ static int amdgpu_info_ioctl(struct drm_device *dev, void *data, struct drm_file
 		if (amdgpu_sriov_vf(adev))
 			dev_info.ids_flags |= AMDGPU_IDS_FLAGS_PREEMPTION;
 		dev_info.virtual_address_offset = AMDGPU_VA_RESERVED_SIZE;
-		dev_info.virtual_address_max = (uint64_t)adev->vm_manager.max_pfn * AMDGPU_GPU_PAGE_SIZE;
+		dev_info.virtual_address_max =
+			min(adev->vm_manager.max_pfn * AMDGPU_GPU_PAGE_SIZE,
+			    AMDGPU_VA_HOLE_START);
 		dev_info.virtual_address_alignment = max((int)PAGE_SIZE, AMDGPU_GPU_PAGE_SIZE);
 		dev_info.pte_fragment_size = (1 << adev->vm_manager.fragment_size) * AMDGPU_GPU_PAGE_SIZE;
 		dev_info.gart_page_size = AMDGPU_GPU_PAGE_SIZE;

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h

@@ -96,6 +96,19 @@ struct amdgpu_bo_list_entry;
 /* hardcode that limit for now */
 #define AMDGPU_VA_RESERVED_SIZE			(8ULL << 20)
 
+/* VA hole for 48bit addresses on Vega10 */
+#define AMDGPU_VA_HOLE_START			0x0000800000000000ULL
+#define AMDGPU_VA_HOLE_END			0xffff800000000000ULL
+
+/*
+ * Hardware is programmed as if the hole doesn't exists with start and end
+ * address values.
+ *
+ * This mask is used to remove the upper 16bits of the VA and so come up with
+ * the linear addr value.
+ */
+#define AMDGPU_VA_HOLE_MASK			0x0000ffffffffffffULL
+
 /* max vmids dedicated for process */
 #define AMDGPU_VM_MAX_RESERVED_VMID	1