| Message ID | 20220823000326.10056-1-afd@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: omapdrm: Improve check for contiguous buffers | expand |
On 8/22/22 7:03 PM, Andrew Davis wrote: > While a scatter-gather table having only 1 entry does imply it is > contiguous, it is a logic error to assume the inverse. Tables can have > more than 1 entry and still be contiguous. Use a proper check here. > > Signed-off-by: Andrew Davis <afd@ti.com> > --- Looks like an old version of this patch got in my to-send queue, please ignore this one, will send updated v2. Thanks, Andrew > drivers/gpu/drm/omapdrm/omap_gem.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c > index cf571796fd26..52c00b795459 100644 > --- a/drivers/gpu/drm/omapdrm/omap_gem.c > +++ b/drivers/gpu/drm/omapdrm/omap_gem.c > @@ -48,7 +48,7 @@ struct omap_gem_object { > * OMAP_BO_MEM_DMA_API flag set) > * > * - buffers imported from dmabuf (with the OMAP_BO_MEM_DMABUF flag set) > - * if they are physically contiguous (when sgt->orig_nents == 1) > + * if they are physically contiguous > * > * - buffers mapped through the TILER when pin_cnt is not zero, in which > * case the DMA address points to the TILER aperture > @@ -148,12 +148,18 @@ u64 omap_gem_mmap_offset(struct drm_gem_object *obj) > return drm_vma_node_offset_addr(&obj->vma_node); > } > > +static bool omap_gem_sgt_is_contiguous(struct sg_table *sgt, size) > +{ > + return !(drm_prime_get_contiguous_size(sgt) < size); > +} > + > static bool omap_gem_is_contiguous(struct omap_gem_object *omap_obj) > { > if (omap_obj->flags & OMAP_BO_MEM_DMA_API) > return true; > > - if ((omap_obj->flags & OMAP_BO_MEM_DMABUF) && omap_obj->sgt->nents == 1) > + if ((omap_obj->flags & OMAP_BO_MEM_DMABUF) && > + omap_gem_sgt_is_contiguous(omap_obj->sgt, omap_obj->base->size)) > return true; > > return false; > @@ -1398,7 +1404,7 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size, > union omap_gem_size gsize; > > /* Without a DMM only physically contiguous buffers can be supported. */ > - if (sgt->orig_nents != 1 && !priv->has_dmm) > + if (!omap_gem_sgt_is_contiguous(sgt, size) && !priv->has_dmm) > return ERR_PTR(-EINVAL); > > gsize.bytes = PAGE_ALIGN(size); > @@ -1412,7 +1418,7 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size, > > omap_obj->sgt = sgt; > > - if (sgt->orig_nents == 1) { > + if (omap_gem_sgt_is_contiguous(sgt, size)) { > omap_obj->dma_addr = sg_dma_address(sgt->sgl); > } else { > /* Create pages list from sgt */
diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c index cf571796fd26..52c00b795459 100644 --- a/drivers/gpu/drm/omapdrm/omap_gem.c +++ b/drivers/gpu/drm/omapdrm/omap_gem.c @@ -48,7 +48,7 @@ struct omap_gem_object { * OMAP_BO_MEM_DMA_API flag set) * * - buffers imported from dmabuf (with the OMAP_BO_MEM_DMABUF flag set) - * if they are physically contiguous (when sgt->orig_nents == 1) + * if they are physically contiguous * * - buffers mapped through the TILER when pin_cnt is not zero, in which * case the DMA address points to the TILER aperture @@ -148,12 +148,18 @@ u64 omap_gem_mmap_offset(struct drm_gem_object *obj) return drm_vma_node_offset_addr(&obj->vma_node); } +static bool omap_gem_sgt_is_contiguous(struct sg_table *sgt, size) +{ + return !(drm_prime_get_contiguous_size(sgt) < size); +} + static bool omap_gem_is_contiguous(struct omap_gem_object *omap_obj) { if (omap_obj->flags & OMAP_BO_MEM_DMA_API) return true; - if ((omap_obj->flags & OMAP_BO_MEM_DMABUF) && omap_obj->sgt->nents == 1) + if ((omap_obj->flags & OMAP_BO_MEM_DMABUF) && + omap_gem_sgt_is_contiguous(omap_obj->sgt, omap_obj->base->size)) return true; return false; @@ -1398,7 +1404,7 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size, union omap_gem_size gsize; /* Without a DMM only physically contiguous buffers can be supported. */ - if (sgt->orig_nents != 1 && !priv->has_dmm) + if (!omap_gem_sgt_is_contiguous(sgt, size) && !priv->has_dmm) return ERR_PTR(-EINVAL); gsize.bytes = PAGE_ALIGN(size); @@ -1412,7 +1418,7 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size, omap_obj->sgt = sgt; - if (sgt->orig_nents == 1) { + if (omap_gem_sgt_is_contiguous(sgt, size)) { omap_obj->dma_addr = sg_dma_address(sgt->sgl); } else { /* Create pages list from sgt */
While a scatter-gather table having only 1 entry does imply it is contiguous, it is a logic error to assume the inverse. Tables can have more than 1 entry and still be contiguous. Use a proper check here. Signed-off-by: Andrew Davis <afd@ti.com> --- drivers/gpu/drm/omapdrm/omap_gem.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)