AMDGPU_GTT_MAX_TRANSFER_SIZE represented the maximum number of
system-page-sized pages that could be transferred in a single
operation. The effective maximum transfer size was intended to be
one PMD-sized mapping.

In the existing code, AMDGPU_GTT_MAX_TRANSFER_SIZE was hard-coded
to 512 pages. This corresponded to 2 MB on 4 KB page-size systems,
matching the PMD size. However, on systems with a non-4 KB page
size, this value no longer matched the PMD size.

This patch changed the calculation of AMDGPU_GTT_MAX_TRANSFER_SIZE
to derive it from PMD_SHIFT and PAGE_SHIFT, ensuring that the
maximum transfer size remained PMD-sized across all system page
sizes.

Additionally, in some places, AMDGPU_GTT_MAX_TRANSFER_SIZE was
implicitly assumed to be based on 4 KB pages. This resulted in
incorrect address offset calculations. This patch updated the
address calculations to correctly handle non-4 KB system page
sizes as well.

amdgpu_ttm_map_buffer() can create both GTT GART entries and
VRAM GART entries. For GTT mappings, amdgpu_gart_map() takes
system page–sized PFNs, and the mappings are created correctly.

However, for VRAM GART mappings, amdgpu_gart_map_vram_range() expects
GPU page–sized PFNs, but CPU page–sized PFNs were being passed,
resulting in incorrect mappings.

This patch updates the code to pass GPU page–sized PFNs to
amdgpu_gart_map_vram_range(), ensuring that VRAM GART mappings are
created correctly.

Signed-off-by: Donet Tom <[email protected]>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 8 +++++---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 2 +-
 drivers/gpu/drm/amd/amdgpu/vce_v1_0.c   | 3 ++-
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 2b931e855abd..e4a11944a1fe 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -191,7 +191,7 @@ static int amdgpu_ttm_map_buffer(struct ttm_buffer_object 
*bo,
        int r;
 
        BUG_ON(adev->mman.buffer_funcs->copy_max_bytes <
-              AMDGPU_GTT_MAX_TRANSFER_SIZE * 8);
+              AMDGPU_GTT_MAX_TRANSFER_SIZE * AMDGPU_GPU_PAGES_IN_CPU_PAGE * 8);
 
        if (WARN_ON(mem->mem_type == AMDGPU_PL_PREEMPT))
                return -EINVAL;
@@ -217,7 +217,7 @@ static int amdgpu_ttm_map_buffer(struct ttm_buffer_object 
*bo,
 
        *addr = adev->gmc.gart_start;
        *addr += (u64)window * AMDGPU_GTT_MAX_TRANSFER_SIZE *
-               AMDGPU_GPU_PAGE_SIZE;
+               AMDGPU_GPU_PAGES_IN_CPU_PAGE * AMDGPU_GPU_PAGE_SIZE;
        *addr += offset;
 
        num_dw = ALIGN(adev->mman.buffer_funcs->copy_num_dw, 8);
@@ -235,7 +235,8 @@ static int amdgpu_ttm_map_buffer(struct ttm_buffer_object 
*bo,
        src_addr += job->ibs[0].gpu_addr;
 
        dst_addr = amdgpu_bo_gpu_offset(adev->gart.bo);
-       dst_addr += window * AMDGPU_GTT_MAX_TRANSFER_SIZE * 8;
+       dst_addr += window * AMDGPU_GTT_MAX_TRANSFER_SIZE *
+               AMDGPU_GPU_PAGES_IN_CPU_PAGE * 8;
        amdgpu_emit_copy_buffer(adev, &job->ibs[0], src_addr,
                                dst_addr, num_bytes, 0);
 
@@ -256,6 +257,7 @@ static int amdgpu_ttm_map_buffer(struct ttm_buffer_object 
*bo,
        } else {
                u64 pa = mm_cur->start + adev->vm_manager.vram_base_offset;
 
+               num_pages *= AMDGPU_GPU_PAGES_IN_CPU_PAGE;
                amdgpu_gart_map_vram_range(adev, pa, 0, num_pages, flags, 
cpu_addr);
        }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index 577ee04ce0bf..d9020a60c13e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -38,7 +38,7 @@
 #define AMDGPU_PL_MMIO_REMAP   (TTM_PL_PRIV + 5)
 #define __AMDGPU_PL_NUM        (TTM_PL_PRIV + 6)
 
-#define AMDGPU_GTT_MAX_TRANSFER_SIZE   512
+#define AMDGPU_GTT_MAX_TRANSFER_SIZE   (1 << (PMD_SHIFT - PAGE_SHIFT))
 #define AMDGPU_GTT_NUM_TRANSFER_WINDOWS        2
 
 extern const struct attribute_group amdgpu_vram_mgr_attr_group;
diff --git a/drivers/gpu/drm/amd/amdgpu/vce_v1_0.c 
b/drivers/gpu/drm/amd/amdgpu/vce_v1_0.c
index 9ae424618556..b2d4114c258c 100644
--- a/drivers/gpu/drm/amd/amdgpu/vce_v1_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/vce_v1_0.c
@@ -48,7 +48,8 @@
 #define VCE_STATUS_VCPU_REPORT_FW_LOADED_MASK  0x02
 
 #define VCE_V1_0_GART_PAGE_START \
-       (AMDGPU_GTT_MAX_TRANSFER_SIZE * AMDGPU_GTT_NUM_TRANSFER_WINDOWS)
+       (AMDGPU_GTT_MAX_TRANSFER_SIZE * AMDGPU_GPU_PAGES_IN_CPU_PAGE * \
+        AMDGPU_GTT_NUM_TRANSFER_WINDOWS)
 #define VCE_V1_0_GART_ADDR_START \
        (VCE_V1_0_GART_PAGE_START * AMDGPU_GPU_PAGE_SIZE)
 
-- 
2.52.0

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