From: Chris Wilson Date: Thu, 1 Aug 2019 12:44:58 +0000 (+0100) Subject: Revert "drm/vgem: fix cache synchronization on arm/arm64" X-Git-Tag: v5.4-rc1~400^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=63dc6e63e682cf756ab8c18aa1b85b0efb358dad;p=platform%2Fkernel%2Flinux-rpi.git Revert "drm/vgem: fix cache synchronization on arm/arm64" 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 Cc: Daniel Vetter Cc: Rob Clark Cc: Sean Paul Acked-by: Sean Paul Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20190801124458.24949-1-chris@chris-wilson.co.uk --- diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c index fc04803f..11a8f99 100644 --- a/drivers/gpu/drm/vgem/vgem_drv.c +++ b/drivers/gpu/drm/vgem/vgem_drv.c @@ -47,16 +47,10 @@ 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); @@ -84,15 +78,40 @@ 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; } @@ -258,93 +277,32 @@ 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); } @@ -352,12 +310,18 @@ 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; }