[PATCH v6 2/8] drm/ttm: Add ttm_bo_access
Christian König
ckoenig.leichtzumerken at gmail.com
Mon Nov 4 19:47:01 UTC 2024
Am 01.11.24 um 00:43 schrieb Matthew Brost:
> On Thu, Oct 31, 2024 at 11:10:42AM -0700, Matthew Brost wrote:
>> Non-contiguous VRAM cannot easily be mapped in TTM nor can non-visible
>> VRAM easily be accessed. Add ttm_bo_access, which is similar to
>> ttm_bo_vm_access, to access such memory.
>>
>> v4:
>> - Fix checkpatch warnings (CI)
>> v5:
>> - Fix checkpatch warnings (CI)
>> v6:
>> - Fix kernel doc (Auld)
>>
> Christian - Do you mind if I merge patch along with the rest of the
> series to drm-xe-next?
I don't see the original patch anywhere in my inbox, please make sure to
CC me while sending things out.
Apart from that I absolutely don't see any justification for this patch.
You move stuff into ttm_bo_util.c which not even remotely belongs in there.
Regards,
Christian.
>
> Matt
>
>> Reported-by: Christoph Manszewski <christoph.manszewski at intel.com>
>> Suggested-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
>> Signed-off-by: Matthew Brost <matthew.brost at intel.com>
>> Tested-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
>> Reviewed-by: Matthew Auld <matthew.auld at intel.com>
>> ---
>> drivers/gpu/drm/ttm/ttm_bo_util.c | 86 +++++++++++++++++++++++++++++++
>> drivers/gpu/drm/ttm/ttm_bo_vm.c | 65 +----------------------
>> include/drm/ttm/ttm_bo.h | 2 +
>> 3 files changed, 89 insertions(+), 64 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
>> index d939925efa81..77e760ea7193 100644
>> --- a/drivers/gpu/drm/ttm/ttm_bo_util.c
>> +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
>> @@ -919,3 +919,89 @@ s64 ttm_lru_walk_for_evict(struct ttm_lru_walk *walk, struct ttm_device *bdev,
>>
>> return progress;
>> }
>> +
>> +static int ttm_bo_access_kmap(struct ttm_buffer_object *bo,
>> + unsigned long offset,
>> + void *buf, int len, int write)
>> +{
>> + unsigned long page = offset >> PAGE_SHIFT;
>> + unsigned long bytes_left = len;
>> + int ret;
>> +
>> + /* Copy a page at a time, that way no extra virtual address
>> + * mapping is needed
>> + */
>> + offset -= page << PAGE_SHIFT;
>> + do {
>> + unsigned long bytes = min(bytes_left, PAGE_SIZE - offset);
>> + struct ttm_bo_kmap_obj map;
>> + void *ptr;
>> + bool is_iomem;
>> +
>> + ret = ttm_bo_kmap(bo, page, 1, &map);
>> + if (ret)
>> + return ret;
>> +
>> + ptr = (void *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
>> + WARN_ON_ONCE(is_iomem);
>> + if (write)
>> + memcpy(ptr, buf, bytes);
>> + else
>> + memcpy(buf, ptr, bytes);
>> + ttm_bo_kunmap(&map);
>> +
>> + page++;
>> + buf += bytes;
>> + bytes_left -= bytes;
>> + offset = 0;
>> + } while (bytes_left);
>> +
>> + return len;
>> +}
>> +
>> +/**
>> + * ttm_bo_access - Helper to access a buffer object
>> + *
>> + * @bo: ttm buffer object
>> + * @offset: access offset into buffer object
>> + * @buf: pointer to caller memory to read into or write from
>> + * @len: length of access
>> + * @write: write access
>> + *
>> + * Utility function to access a buffer object. Useful when buffer object cannot
>> + * be easily mapped (non-contiguous, non-visible, etc...).
>> + *
>> + * Returns:
>> + * @len if successful, negative error code on failure.
>> + */
>> +int ttm_bo_access(struct ttm_buffer_object *bo, unsigned long offset,
>> + void *buf, int len, int write)
>> +{
>> + int ret;
>> +
>> + if (len < 1 || (offset + len) > bo->base.size)
>> + return -EIO;
>> +
>> + ret = ttm_bo_reserve(bo, true, false, NULL);
>> + if (ret)
>> + return ret;
>> +
>> + switch (bo->resource->mem_type) {
>> + case TTM_PL_SYSTEM:
>> + fallthrough;
>> + case TTM_PL_TT:
>> + ret = ttm_bo_access_kmap(bo, offset, buf, len, write);
>> + break;
>> + default:
>> + if (bo->bdev->funcs->access_memory)
>> + ret = bo->bdev->funcs->access_memory
>> + (bo, offset, buf, len, write);
>> + else
>> + ret = -EIO;
>> + }
>> +
>> + ttm_bo_unreserve(bo);
>> +
>> + return ret;
>> +}
>> +EXPORT_SYMBOL(ttm_bo_access);
>> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
>> index 2c699ed1963a..20b1e5f78684 100644
>> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
>> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
>> @@ -366,45 +366,6 @@ void ttm_bo_vm_close(struct vm_area_struct *vma)
>> }
>> EXPORT_SYMBOL(ttm_bo_vm_close);
>>
>> -static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo,
>> - unsigned long offset,
>> - uint8_t *buf, int len, int write)
>> -{
>> - unsigned long page = offset >> PAGE_SHIFT;
>> - unsigned long bytes_left = len;
>> - int ret;
>> -
>> - /* Copy a page at a time, that way no extra virtual address
>> - * mapping is needed
>> - */
>> - offset -= page << PAGE_SHIFT;
>> - do {
>> - unsigned long bytes = min(bytes_left, PAGE_SIZE - offset);
>> - struct ttm_bo_kmap_obj map;
>> - void *ptr;
>> - bool is_iomem;
>> -
>> - ret = ttm_bo_kmap(bo, page, 1, &map);
>> - if (ret)
>> - return ret;
>> -
>> - ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
>> - WARN_ON_ONCE(is_iomem);
>> - if (write)
>> - memcpy(ptr, buf, bytes);
>> - else
>> - memcpy(buf, ptr, bytes);
>> - ttm_bo_kunmap(&map);
>> -
>> - page++;
>> - buf += bytes;
>> - bytes_left -= bytes;
>> - offset = 0;
>> - } while (bytes_left);
>> -
>> - return len;
>> -}
>> -
>> int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
>> void *buf, int len, int write)
>> {
>> @@ -412,32 +373,8 @@ int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
>> unsigned long offset = (addr) - vma->vm_start +
>> ((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node))
>> << PAGE_SHIFT);
>> - int ret;
>> -
>> - if (len < 1 || (offset + len) > bo->base.size)
>> - return -EIO;
>>
>> - ret = ttm_bo_reserve(bo, true, false, NULL);
>> - if (ret)
>> - return ret;
>> -
>> - switch (bo->resource->mem_type) {
>> - case TTM_PL_SYSTEM:
>> - fallthrough;
>> - case TTM_PL_TT:
>> - ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
>> - break;
>> - default:
>> - if (bo->bdev->funcs->access_memory)
>> - ret = bo->bdev->funcs->access_memory(
>> - bo, offset, buf, len, write);
>> - else
>> - ret = -EIO;
>> - }
>> -
>> - ttm_bo_unreserve(bo);
>> -
>> - return ret;
>> + return ttm_bo_access(bo, offset, buf, len, write);
>> }
>> EXPORT_SYMBOL(ttm_bo_vm_access);
>>
>> diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h
>> index 5804408815be..8ea11cd8df39 100644
>> --- a/include/drm/ttm/ttm_bo.h
>> +++ b/include/drm/ttm/ttm_bo.h
>> @@ -421,6 +421,8 @@ void ttm_bo_unpin(struct ttm_buffer_object *bo);
>> int ttm_bo_evict_first(struct ttm_device *bdev,
>> struct ttm_resource_manager *man,
>> struct ttm_operation_ctx *ctx);
>> +int ttm_bo_access(struct ttm_buffer_object *bo, unsigned long offset,
>> + void *buf, int len, int write);
>> vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
>> struct vm_fault *vmf);
>> vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
>> --
>> 2.34.1
>>
More information about the Intel-xe
mailing list