On 2021-11-09 2:12 p.m., Ramesh Errabolu wrote:
MMIO/DOORBELL BOs encode control data and should be pinned in GTT
domain before enabling PCIe connected peer devices in accessing it
Signed-off-by: Ramesh Errabolu <Ramesh.Errabolu@xxxxxxx>
Reviewed-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
---
.../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 70 +++++++++++++++++++
1 file changed, 70 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 08675f89bfb2..5e063fac0250 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -1297,6 +1297,56 @@ static int init_kfd_vm(struct amdgpu_vm *vm, void **process_info,
return ret;
}
+/**
+ * amdgpu_amdkfd_gpuvm_pin_bo() - Pins a BO using following criteria
+ * @bo: Handle of buffer object being pinned
+ * @domain: Domain into which BO should be pinned
+ *
+ * - USERPTR BOs are UNPINNABLE and will return error
+ * - All other BO types (GTT, VRAM, MMIO and DOORBELL) will have their
+ * PIN count incremented. It is valid to PIN a BO multiple times
+ *
+ * Return: ZERO if successful in pinning, Non-Zero in case of error.
+ * Will return -EINVAL if input BO parameter is a USERPTR type.
+ */
+static int amdgpu_amdkfd_gpuvm_pin_bo(struct amdgpu_bo *bo, u32 domain)
+{
+ int ret = 0;
+
+ ret = amdgpu_bo_reserve(bo, false);
+ if (unlikely(ret))
+ return ret;
+
+ ret = amdgpu_bo_pin_restricted(bo, domain, 0, 0);
+ if (ret)
+ pr_err("Error in Pinning BO to domain: %d\n", domain);
+
+ amdgpu_bo_sync_wait(bo, AMDGPU_FENCE_OWNER_KFD, false);
+ amdgpu_bo_unreserve(bo);
+
+ return ret;
+}
+
+/**
+ * amdgpu_amdkfd_gpuvm_unpin_bo() - Unpins BO using following criteria
+ * @bo: Handle of buffer object being unpinned
+ *
+ * - Is a illegal request for USERPTR BOs and is ignored
+ * - All other BO types (GTT, VRAM, MMIO and DOORBELL) will have their
+ * PIN count decremented. Calls to UNPIN must balance calls to PIN
+ */
+void amdgpu_amdkfd_gpuvm_unpin_bo(struct amdgpu_bo *bo)
+{
+ int ret = 0;
+
+ ret = amdgpu_bo_reserve(bo, false);
+ if (unlikely(ret))
+ return;
+
+ amdgpu_bo_unpin(bo);
+ amdgpu_bo_unreserve(bo);
+}
+
int amdgpu_amdkfd_gpuvm_acquire_process_vm(struct amdgpu_device *adev,
struct file *filp, u32 pasid,
void **process_info,
@@ -1523,10 +1573,22 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
if (offset)
*offset = amdgpu_bo_mmap_offset(bo);
+ if (flags & (KFD_IOC_ALLOC_MEM_FLAGS_DOORBELL |
+ KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP)) {
+ ret = amdgpu_amdkfd_gpuvm_pin_bo(bo, AMDGPU_GEM_DOMAIN_GTT);
+ if (ret) {
+ pr_err("Pinning MMIO/DOORBELL BO during ALLOC FAILED\n");
+ goto err_pin_bo;
+ }
+ bo->allowed_domains = AMDGPU_GEM_DOMAIN_GTT;
+ bo->preferred_domains = AMDGPU_GEM_DOMAIN_GTT;
+ }
+
return 0;
allocate_init_user_pages_failed:
remove_kgd_mem_from_kfd_bo_list(*mem, avm->process_info);
+err_pin_bo:
drm_vma_node_revoke(&gobj->vma_node, drm_priv);
err_node_allow:
drm_gem_object_put(gobj);
@@ -1559,6 +1621,14 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
bool is_imported = false;
mutex_lock(&mem->lock);
+
+ /* Unpin MMIO/DOORBELL BO's that were pinnned during allocation */
+ if (mem->alloc_flags &
+ (KFD_IOC_ALLOC_MEM_FLAGS_DOORBELL |
+ KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP)) {
+ amdgpu_amdkfd_gpuvm_unpin_bo(mem->bo);
+ }
+
mapped_to_gpu_memory = mem->mapped_to_gpu_memory;
is_imported = mem->is_imported;
mutex_unlock(&mem->lock);
