Hi Matt,
在 2025/2/26 12:43, Matthew Brost 写道:
On Wed, Feb 26, 2025 at 10:00:22AM +0800, Mingcong Bai via B4 Relay wrote:
From: Mingcong Bai <jeffbai@xxxxxxx>
As this component hooks into userspace API, it should be assumed that it
will play well with non-4K/64K pages.
Use `PAGE_SIZE' as the final reference for page alignment instead.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Fixes: 801989b08aff ("drm/xe/uapi: Make constant comments visible in kernel doc")
Tested-by: Mingcong Bai <jeffbai@xxxxxxx>
Tested-by: Haien Liang <27873200@xxxxxx>
Tested-by: Shirong Liu <lsr1024@xxxxxx>
Tested-by: Haofeng Wu <s2600cw2@xxxxxxx>
Link: https://github.com/FanFansfan/loongson-linux/commit/22c55ab3931c32410a077b3ddb6dca3f28223360
Co-developed-by: Shang Yatsen <429839446@xxxxxx>
Signed-off-by: Shang Yatsen <429839446@xxxxxx>
Signed-off-by: Mingcong Bai <jeffbai@xxxxxxx>
---
drivers/gpu/drm/xe/xe_query.c | 2 +-
include/uapi/drm/xe_drm.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_query.c b/drivers/gpu/drm/xe/xe_query.c
index c059639613f7b548c168f808b7b7b354f1cf3c94..8a017c526942d1f2b401e8b9a4244e6083d7b1e5 100644
--- a/drivers/gpu/drm/xe/xe_query.c
+++ b/drivers/gpu/drm/xe/xe_query.c
@@ -336,7 +336,7 @@ static int query_config(struct xe_device *xe, struct drm_xe_device_query *query)
config->info[DRM_XE_QUERY_CONFIG_FLAGS] =
DRM_XE_QUERY_CONFIG_FLAG_HAS_VRAM;
config->info[DRM_XE_QUERY_CONFIG_MIN_ALIGNMENT] =
- xe->info.vram_flags & XE_VRAM_FLAGS_NEED64K ? SZ_64K : SZ_4K;
+ xe->info.vram_flags & XE_VRAM_FLAGS_NEED64K ? SZ_64K : PAGE_SIZE;
We should probably assert or build a bug somewhere to ensure SZ_64K >=
PAGE_SIZE for future-proofing. Otherwise, I think the patch makes sense.
One more comment below.
config->info[DRM_XE_QUERY_CONFIG_VA_BITS] = xe->info.va_bits;
config->info[DRM_XE_QUERY_CONFIG_MAX_EXEC_QUEUE_PRIORITY] =
xe_exec_queue_device_get_max_priority(xe);
diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
index f62689ca861a4673b885629460c11d6f3bc6523d..db7cf904926ebd6789a29d620161ac051e59f13f 100644
--- a/include/uapi/drm/xe_drm.h
+++ b/include/uapi/drm/xe_drm.h
@@ -394,7 +394,7 @@ struct drm_xe_query_mem_regions {
* - %DRM_XE_QUERY_CONFIG_FLAG_HAS_VRAM - Flag is set if the device
* has usable VRAM
* - %DRM_XE_QUERY_CONFIG_MIN_ALIGNMENT - Minimal memory alignment
- * required by this device, typically SZ_4K or SZ_64K
+ * required by this device, typically PAGE_SIZE.
So I think the kernel doc needs bit more updating here, how about:
Minimal memory alignment required by this device and the CPU. The
minimum page size for the device is usually SZ_4K or SZ_64K, while for
the CPU, it is PAGE_SIZE. This value is calculated by
max(min_gpu_page_size, PAGE_SIZE). This alignment is enforced on
buffer object allocations and VM binds.
I will revise as such, taking into account other comments sent in before
I get my next revision together. Thanks!
Best Regards,
Mingcong Bai
Again welcome others CC'd suggestion on this updated kernel doc.
Matt
* - %DRM_XE_QUERY_CONFIG_VA_BITS - Maximum bits of a virtual address
* - %DRM_XE_QUERY_CONFIG_MAX_EXEC_QUEUE_PRIORITY - Value of the highest
* available exec queue priority
--
2.48.1
