Le 04/11/2025 à 16:24, Christian König a écrit :
On 11/4/25 16:08, Pierre-Eric Pelloux-Prayer wrote:
Le 04/11/2025 à 14:23, Christian König a écrit :
On 11/3/25 23:23, Timur Kristóf wrote:
GART contains some pages in its address space that come before
the GTT and are used for BO copies.
Instead of hardcoding the size of the GART space before GTT,
make it a field in the amdgpu_gmc struct. This allows us to map
more things in GART before GTT.
Split this into a separate patch to make it easier to bisect,
in case there are any errors in the future.
Signed-off-by: Timur Kristóf <[email protected]>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c | 2 ++
drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h | 1 +
drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c | 2 +-
3 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
index 97b562a79ea8..bf31bd022d6d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
@@ -325,6 +325,8 @@ void amdgpu_gmc_gart_location(struct amdgpu_device *adev,
struct amdgpu_gmc *mc,
break;
}
+ mc->num_gart_pages_before_gtt =
+ AMDGPU_GTT_MAX_TRANSFER_SIZE * AMDGPU_GTT_NUM_TRANSFER_WINDOWS;
mc->gart_start &= ~(four_gb - 1);
mc->gart_end = mc->gart_start + mc->gart_size - 1;
dev_info(adev->dev, "GART: %lluM 0x%016llX - 0x%016llX\n",
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
index 55097ca10738..568eed3eb557 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
@@ -266,6 +266,7 @@ struct amdgpu_gmc {
u64 fb_end;
unsigned vram_width;
u64 real_vram_size;
+ u32 num_gart_pages_before_gtt;
int vram_mtrr;
u64 mc_mask;
const struct firmware *fw; /* MC firmware */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
index 0760e70402ec..4c2563a70c2b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
@@ -283,7 +283,7 @@ int amdgpu_gtt_mgr_init(struct amdgpu_device *adev,
uint64_t gtt_size)
ttm_resource_manager_init(man, &adev->mman.bdev, gtt_size);
- start = AMDGPU_GTT_MAX_TRANSFER_SIZE * AMDGPU_GTT_NUM_TRANSFER_WINDOWS;
+ start = adev->gmc.num_gart_pages_before_gtt;
I would prefer that we have a single function which returns the number of GART
pages we need before the dynamic GTT mapping.
But let me see how Pierre-Eric solved this first.
The only conflicting change with my series is that I changed this:
- start = AMDGPU_GTT_MAX_TRANSFER_SIZE * AMDGPU_GTT_NUM_TRANSFER_WINDOWS;
+ start = AMDGPU_GTT_MAX_TRANSFER_SIZE * reserved_windows;
So to account for Timur's change, I would only need to adapt this part:
+ mc->num_gart_pages_before_gtt =
+ AMDGPU_GTT_MAX_TRANSFER_SIZE * reserved_windows;
Where is reserved_windows comming from in this calculation?
It comes from amdgpu_ttm_init.
See commit "drm/amdgpu: allocate multiple clear entities".
Pierre-Eric
