Am 13.07.2017 um 23:08 schrieb Felix Kuehling:
> Allows gdb to access contents of user mode mapped BOs. VRAM access
> requires the driver to implement a new callback in ttm_bo_driver.
One more comment additionally to what Michel already wrote below, apart
from that it looks good to me.
>
> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
> ---
> drivers/gpu/drm/ttm/ttm_bo_vm.c | 66 ++++++++++++++++++++++++++++++++++++++++-
> include/drm/ttm/ttm_bo_driver.h | 12 ++++++++
> 2 files changed, 77 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> index 9f53df9..0ef2eb9 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> @@ -294,10 +294,74 @@ static void ttm_bo_vm_close(struct vm_area_struct *vma)
> vma->vm_private_data = NULL;
> }
>
> +static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo,
> + unsigned long offset,
> + void *buf, int len, int write)
> +{
> + unsigned long first_page = offset >> PAGE_SHIFT;
> + unsigned long last_page = (offset + len - 1) >> PAGE_SHIFT;
> + unsigned long num_pages = last_page - first_page + 1;
> + struct ttm_bo_kmap_obj map;
> + void *ptr;
> + bool is_iomem;
> + int ret;
> +
> + ret = ttm_bo_kmap(bo, first_page, num_pages, &map);
> + if (ret)
> + return ret;
> +
> + offset -= first_page << PAGE_SHIFT;
> + ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
> + WARN_ON(is_iomem);
> + if (write)
> + memcpy(ptr, buf, len);
> + else
> + memcpy(buf, ptr, len);
> + ttm_bo_kunmap(&map);
> +
> + return len;
> +}
> +
> +static int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
> + void *buf, int len, int write)
> +{
> + unsigned long offset = (addr) - vma->vm_start;
> + struct ttm_buffer_object *bo = vma->vm_private_data;
> + int ret;
> +
> + if (len < 1 || (offset + len) >> PAGE_SHIFT > bo->num_pages)
> + return -EIO;
> +
> + ret = ttm_bo_reserve(bo, true, false, NULL);
> + if (ret)
> + return ret;
> +
> + switch(bo->mem.mem_type) {
> + case TTM_PL_SYSTEM:
When the BO is in the system domain you need to add this as well I think:
if (unlikely(bo->ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(bo->ttm);
if (unlikely(ret != 0))
return ret;
}
Regards,
Christian.
> + case TTM_PL_TT:
> + ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
> + break;
> + case TTM_PL_VRAM:
> + if (bo->bdev->driver->access_vram)
> + ret = bo->bdev->driver->access_vram(
> + bo, offset, buf, len, write);
> + else
> + ret = -EIO;
> + break;
> + default:
> + ret = -EIO;
> + }
> +
> + ttm_bo_unreserve(bo);
> +
> + return ret;
> +}
> +
> static const struct vm_operations_struct ttm_bo_vm_ops = {
> .fault = ttm_bo_vm_fault,
> .open = ttm_bo_vm_open,
> - .close = ttm_bo_vm_close
> + .close = ttm_bo_vm_close,
> + .access = ttm_bo_vm_access
> };
>
> static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
> diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
> index 6bbd34d..6ce5094 100644
> --- a/include/drm/ttm/ttm_bo_driver.h
> +++ b/include/drm/ttm/ttm_bo_driver.h
> @@ -471,6 +471,18 @@ struct ttm_bo_driver {
> */
> unsigned long (*io_mem_pfn)(struct ttm_buffer_object *bo,
> unsigned long page_offset);
> +
> + /**
> + * Read/write VRAM buffers for ptrace access
> + *
> + * @bo: the BO to access
> + * @offset: the offset from the start of the BO
> + * @buf: pointer to source/destination buffer
> + * @len: number of bytes to copy
> + * @write: whether to read (0) from or write (non-0) to BO
> + */
> + int (*access_vram)(struct ttm_buffer_object *bo, unsigned long offset,
> + void *buf, int len, int write);
> };
>
> /**
