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>
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
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