On 05/01/2024 18:46, Dmitry Osipenko wrote:
> From: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
>
> If some the pages or sgt allocation failed, we shouldn't release the
> pages ref we got earlier, otherwise we will end up with unbalanced
> get/put_pages() calls. We should instead leave everything in place
> and let the BO release function deal with extra cleanup when the object
> is destroyed, or let the fault handler try again next time it's called.
>
> Fixes: 187d2929206e ("drm/panfrost: Add support for GPU heap allocations")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> Co-developed-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
Reviewed-by: Steven Price <steven.price@xxxxxxx>
> ---
> drivers/gpu/drm/panfrost/panfrost_mmu.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> index bd5a0073009d..4a0b4bf03f1a 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> @@ -502,11 +502,18 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
> mapping_set_unevictable(mapping);
>
> for (i = page_offset; i < page_offset + NUM_FAULT_PAGES; i++) {
> + /* Can happen if the last fault only partially filled this
> + * section of the pages array before failing. In that case
> + * we skip already filled pages.
> + */
> + if (pages[i])
> + continue;
> +
> pages[i] = shmem_read_mapping_page(mapping, i);
> if (IS_ERR(pages[i])) {
> ret = PTR_ERR(pages[i]);
> pages[i] = NULL;
> - goto err_pages;
> + goto err_unlock;
> }
> }
>
> @@ -514,7 +521,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
> ret = sg_alloc_table_from_pages(sgt, pages + page_offset,
> NUM_FAULT_PAGES, 0, SZ_2M, GFP_KERNEL);
> if (ret)
> - goto err_pages;
> + goto err_unlock;
>
> ret = dma_map_sgtable(pfdev->dev, sgt, DMA_BIDIRECTIONAL, 0);
> if (ret)
> @@ -537,8 +544,6 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
>
> err_map:
> sg_free_table(sgt);
> -err_pages:
> - drm_gem_shmem_put_pages_locked(&bo->base);
> err_unlock:
> dma_resv_unlock(obj->resv);
> err_bo:
