On Thu, Aug 01, 2019 at 01:44:58PM +0100, Chris Wilson wrote: > commit 7e9e5ead55be ("drm/vgem: fix cache synchronization on arm/arm64") > broke all of the !llc i915-vgem coherency tests in CI, and left the HW > very, very unhappy (which is even more scary). > > Fixes: 7e9e5ead55be ("drm/vgem: fix cache synchronization on arm/arm64") > Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
Acked-by: Sean Paul <s...@poorly.run> > Cc: Daniel Vetter <daniel.vet...@ffwll.ch> > Cc: Rob Clark <robdcl...@chromium.org> > Cc: Sean Paul <seanp...@chromium.org> > --- > drivers/gpu/drm/vgem/vgem_drv.c | 130 ++++++++++++-------------------- > 1 file changed, 47 insertions(+), 83 deletions(-) > > diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c > index b98689fb0d5d..5bd60ded3d81 100644 > --- a/drivers/gpu/drm/vgem/vgem_drv.c > +++ b/drivers/gpu/drm/vgem/vgem_drv.c > @@ -54,16 +54,10 @@ static struct vgem_device { > struct platform_device *platform; > } *vgem_device; > > -static void sync_and_unpin(struct drm_vgem_gem_object *bo); > -static struct page **pin_and_sync(struct drm_vgem_gem_object *bo); > - > static void vgem_gem_free_object(struct drm_gem_object *obj) > { > struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj); > > - if (!obj->import_attach) > - sync_and_unpin(vgem_obj); > - > kvfree(vgem_obj->pages); > mutex_destroy(&vgem_obj->pages_lock); > > @@ -91,15 +85,40 @@ static vm_fault_t vgem_gem_fault(struct vm_fault *vmf) > return VM_FAULT_SIGBUS; > > mutex_lock(&obj->pages_lock); > - if (!obj->pages) > - pin_and_sync(obj); > if (obj->pages) { > get_page(obj->pages[page_offset]); > vmf->page = obj->pages[page_offset]; > ret = 0; > } > mutex_unlock(&obj->pages_lock); > + if (ret) { > + struct page *page; > + > + page = shmem_read_mapping_page( > + file_inode(obj->base.filp)->i_mapping, > + page_offset); > + if (!IS_ERR(page)) { > + vmf->page = page; > + ret = 0; > + } else switch (PTR_ERR(page)) { > + case -ENOSPC: > + case -ENOMEM: > + ret = VM_FAULT_OOM; > + break; > + case -EBUSY: > + ret = VM_FAULT_RETRY; > + break; > + case -EFAULT: > + case -EINVAL: > + ret = VM_FAULT_SIGBUS; > + break; > + default: > + WARN_ON(PTR_ERR(page)); > + ret = VM_FAULT_SIGBUS; > + break; > + } > > + } > return ret; > } > > @@ -265,93 +284,32 @@ static const struct file_operations vgem_driver_fops = { > .release = drm_release, > }; > > -/* Called under pages_lock, except in free path (where it can't race): */ > -static void sync_and_unpin(struct drm_vgem_gem_object *bo) > -{ > - struct drm_device *dev = bo->base.dev; > - > - if (bo->table) { > - dma_sync_sg_for_cpu(dev->dev, bo->table->sgl, > - bo->table->nents, DMA_BIDIRECTIONAL); > - sg_free_table(bo->table); > - kfree(bo->table); > - bo->table = NULL; > - } > - > - if (bo->pages) { > - drm_gem_put_pages(&bo->base, bo->pages, true, true); > - bo->pages = NULL; > - } > -} > - > -static struct page **pin_and_sync(struct drm_vgem_gem_object *bo) > -{ > - struct drm_device *dev = bo->base.dev; > - int npages = bo->base.size >> PAGE_SHIFT; > - struct page **pages; > - struct sg_table *sgt; > - > - WARN_ON(!mutex_is_locked(&bo->pages_lock)); > - > - pages = drm_gem_get_pages(&bo->base); > - if (IS_ERR(pages)) { > - bo->pages_pin_count--; > - mutex_unlock(&bo->pages_lock); > - return pages; > - } > - > - sgt = drm_prime_pages_to_sg(pages, npages); > - if (IS_ERR(sgt)) { > - dev_err(dev->dev, > - "failed to allocate sgt: %ld\n", > - PTR_ERR(bo->table)); > - drm_gem_put_pages(&bo->base, pages, false, false); > - mutex_unlock(&bo->pages_lock); > - return ERR_CAST(bo->table); > - } > - > - /* > - * Flush the object from the CPU cache so that importers > - * can rely on coherent indirect access via the exported > - * dma-address. > - */ > - dma_sync_sg_for_device(dev->dev, sgt->sgl, > - sgt->nents, DMA_BIDIRECTIONAL); > - > - bo->pages = pages; > - bo->table = sgt; > - > - return pages; > -} > - > static struct page **vgem_pin_pages(struct drm_vgem_gem_object *bo) > { > - struct page **pages; > - > mutex_lock(&bo->pages_lock); > - if (bo->pages_pin_count++ == 0 && !bo->pages) { > - pages = pin_and_sync(bo); > - } else { > - WARN_ON(!bo->pages); > - pages = bo->pages; > + if (bo->pages_pin_count++ == 0) { > + struct page **pages; > + > + pages = drm_gem_get_pages(&bo->base); > + if (IS_ERR(pages)) { > + bo->pages_pin_count--; > + mutex_unlock(&bo->pages_lock); > + return pages; > + } > + > + bo->pages = pages; > } > mutex_unlock(&bo->pages_lock); > > - return pages; > + return bo->pages; > } > > static void vgem_unpin_pages(struct drm_vgem_gem_object *bo) > { > - /* > - * We shouldn't hit this for imported bo's.. in the import > - * case we don't own the scatter-table > - */ > - WARN_ON(bo->base.import_attach); > - > mutex_lock(&bo->pages_lock); > if (--bo->pages_pin_count == 0) { > - WARN_ON(!bo->table); > - sync_and_unpin(bo); > + drm_gem_put_pages(&bo->base, bo->pages, true, true); > + bo->pages = NULL; > } > mutex_unlock(&bo->pages_lock); > } > @@ -359,12 +317,18 @@ static void vgem_unpin_pages(struct drm_vgem_gem_object > *bo) > static int vgem_prime_pin(struct drm_gem_object *obj) > { > struct drm_vgem_gem_object *bo = to_vgem_bo(obj); > + long n_pages = obj->size >> PAGE_SHIFT; > struct page **pages; > > pages = vgem_pin_pages(bo); > if (IS_ERR(pages)) > return PTR_ERR(pages); > > + /* Flush the object from the CPU cache so that importers can rely > + * on coherent indirect access via the exported dma-address. > + */ > + drm_clflush_pages(pages, n_pages); > + > return 0; > } > > -- > 2.23.0.rc0 > > _______________________________________________ > Intel-gfx mailing list > intel-...@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Sean Paul, Software Engineer, Google / Chromium OS _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel