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Revert "drm/vgem: fix cache synchronization on arm/arm64" 

commit 7e9e5ead55 ("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: 7e9e5ead55 ("drm/vgem: fix cache synchronization on arm/arm64")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Rob Clark <robdclark@chromium.org>
Cc: Sean Paul <seanpaul@chromium.org>
Acked-by: Sean Paul <sean@poorly.run>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190801124458.24949-1-chris@chris-wilson.co.uk
alistair/sunxi64-5.4-dsi
Chris Wilson 2019-08-01 13:44:58 +01:00 committed by Daniel Vetter
parent 5fd5d2b7c5
commit 63dc6e63e6
1 changed files with 47 additions and 83 deletions
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130
drivers/gpu/drm/vgem/vgem_drv.c
View File

@ -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;
}