From 1e739b177cd22b3268c8c1053aba7cce16751ad3 Mon Sep 17 00:00:00 2001
From: Jonathan Kim <jonathan.kim@amd.com>
Date: Tue, 18 Jan 2022 10:48:49 -0500
Subject: drm/amdgpu: fix broken debug sdma vram access function
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Git-commit: 590e86fe3462da81f1cbc4fc8d4cbf8b16b4f968
Patch-mainline: v5.18-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

Debug VRAM access through SDMA has several broken parts resulting in
silent MMIO fallback.

BO kernel creation takes the location of the cpu addr pointer, not
the pointer itself for address kmap.

drm_dev_enter return true on success so change access check.

The source BO is reserved but not pinned so find the address using the
cursor offset relative to its memory domain start.

Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index ecebd75b28bb..eeb1e5207196 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1406,6 +1406,7 @@ static int amdgpu_ttm_access_memory_sdma(struct ttm_buffer_object *bo,
 {
 	struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
 	struct amdgpu_device *adev = amdgpu_ttm_adev(abo->tbo.bdev);
+	struct amdgpu_res_cursor src_mm;
 	struct amdgpu_job *job;
 	struct dma_fence *fence;
 	uint64_t src_addr, dst_addr;
@@ -1418,9 +1419,8 @@ static int amdgpu_ttm_access_memory_sdma(struct ttm_buffer_object *bo,
 	if (!adev->mman.sdma_access_ptr)
 		return -EACCES;
 
-	r = drm_dev_enter(adev_to_drm(adev), &idx);
-	if (r)
-		return r;
+	if (!drm_dev_enter(adev_to_drm(adev), &idx))
+		return -ENODEV;
 
 	if (write)
 		memcpy(adev->mman.sdma_access_ptr, buf, len);
@@ -1430,7 +1430,8 @@ static int amdgpu_ttm_access_memory_sdma(struct ttm_buffer_object *bo,
 	if (r)
 		goto out;
 
-	src_addr = amdgpu_bo_gpu_offset(abo);
+	amdgpu_res_first(abo->tbo.resource, offset, len, &src_mm);
+	src_addr = amdgpu_ttm_domain_start(adev, bo->resource->mem_type) + src_mm.start;
 	dst_addr = amdgpu_bo_gpu_offset(adev->mman.sdma_access_bo);
 	if (write)
 		swap(src_addr, dst_addr);
@@ -1828,7 +1829,7 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
 	if (amdgpu_bo_create_kernel(adev, PAGE_SIZE, PAGE_SIZE,
 				AMDGPU_GEM_DOMAIN_GTT,
 				&adev->mman.sdma_access_bo, NULL,
-				adev->mman.sdma_access_ptr))
+				&adev->mman.sdma_access_ptr))
 		DRM_WARN("Debug VRAM access will use slowpath MM access\n");
 
 	return 0;
@@ -1852,6 +1853,8 @@ void amdgpu_ttm_fini(struct amdgpu_device *adev)
 	if (adev->mman.stolen_reserved_size)
 		amdgpu_bo_free_kernel(&adev->mman.stolen_reserved_memory,
 				      NULL, NULL);
+	amdgpu_bo_free_kernel(&adev->mman.sdma_access_bo, NULL,
+					&adev->mman.sdma_access_ptr);
 	amdgpu_ttm_fw_reserve_vram_fini(adev);
 
 	if (drm_dev_enter(adev_to_drm(adev), &idx)) {
@@ -1871,8 +1874,6 @@ void amdgpu_ttm_fini(struct amdgpu_device *adev)
 	ttm_range_man_fini(&adev->mman.bdev, AMDGPU_PL_OA);
 	ttm_device_fini(&adev->mman.bdev);
 	adev->mman.initialized = false;
-	amdgpu_bo_free_kernel(&adev->mman.sdma_access_bo, NULL,
-					&adev->mman.sdma_access_ptr);
 	DRM_INFO("amdgpu: ttm finalized\n");
 }
 
-- 
2.38.1