Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>
Thanks for getting to this!
On Thu, 2023-05-18 at 15:42 +0200, Christoph Hellwig wrote:
> Drivers have no business looking into dma-mapping internals and check
> what backend is used. Unfortunstely the DRM core is still broken and
> tries to do plain page allocations instead of using DMA API allocators
> by default and uses various bandaids on when to use dma_alloc_coherent.
>
> Switch nouveau to use the same (broken) scheme as amdgpu and radeon
> to remove the last driver user of is_swiotlb_active.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> drivers/gpu/drm/nouveau/nouveau_ttm.c | 10 +++-------
> 1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_ttm.c b/drivers/gpu/drm/nouveau/nouveau_ttm.c
> index 1469a88910e45d..486f39f31a38df 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_ttm.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_ttm.c
> @@ -24,9 +24,9 @@
> */
>
> #include <linux/limits.h>
> -#include <linux/swiotlb.h>
>
> #include <drm/ttm/ttm_range_manager.h>
> +#include <drm/drm_cache.h>
>
> #include "nouveau_drv.h"
> #include "nouveau_gem.h"
> @@ -265,7 +265,6 @@ nouveau_ttm_init(struct nouveau_drm *drm)
> struct nvkm_pci *pci = device->pci;
> struct nvif_mmu *mmu = &drm->client.mmu;
> struct drm_device *dev = drm->dev;
> - bool need_swiotlb = false;
> int typei, ret;
>
> ret = nouveau_ttm_init_host(drm, 0);
> @@ -300,13 +299,10 @@ nouveau_ttm_init(struct nouveau_drm *drm)
> drm->agp.cma = pci->agp.cma;
> }
>
> -#if IS_ENABLED(CONFIG_SWIOTLB) && IS_ENABLED(CONFIG_X86)
> - need_swiotlb = is_swiotlb_active(dev->dev);
> -#endif
> -
> ret = ttm_device_init(&drm->ttm.bdev, &nouveau_bo_driver, drm->dev->dev,
> dev->anon_inode->i_mapping,
> - dev->vma_offset_manager, need_swiotlb,
> + dev->vma_offset_manager,
> + drm_need_swiotlb(drm->client.mmu.dmabits),
> drm->client.mmu.dmabits <= 32);
> if (ret) {
> NV_ERROR(drm, "error initialising bo driver, %d\n", ret);
--
Cheers,
Lyude Paul (she/her)
Software Engineer at Red Hat
