drm: add fault handler support so as to be more like possible upstream

(cherry picked from commit 10d5b037b85706037df89bf0275436797e4eb559)

1 files changed, 99 insertions, 0 deletions

diff --git a/linux-core/drm_compat.c b/linux-core/drm_compat.c
index aa825f32..d06b9d24 100644
--- a/linux-core/drm_compat.c
+++ b/linux-core/drm_compat.c
@@ -806,3 +806,102 @@ void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type,
 EXPORT_SYMBOL(kmap_atomic_prot_pfn);
 #endif
 
+#ifdef DRM_FULL_MM_COMPAT
+#ifdef DRM_NO_FAULT
+unsigned long drm_bo_vm_nopfn(struct vm_area_struct *vma,
+			      unsigned long address)
+{
+	struct drm_buffer_object *bo = (struct drm_buffer_object *) vma->vm_private_data;
+	unsigned long page_offset;
+	struct page *page = NULL;
+	struct drm_ttm *ttm;
+	struct drm_device *dev;
+	unsigned long pfn;
+	int err;
+	unsigned long bus_base;
+	unsigned long bus_offset;
+	unsigned long bus_size;
+	unsigned long ret = NOPFN_REFAULT;
+
+	if (address > vma->vm_end)
+		return NOPFN_SIGBUS;
+
+	dev = bo->dev;
+	err = drm_bo_read_lock(&dev->bm.bm_lock, 1);
+	if (err)
+		return NOPFN_REFAULT;
+
+	err = mutex_lock_interruptible(&bo->mutex);
+	if (err) {
+		drm_bo_read_unlock(&dev->bm.bm_lock);
+		return NOPFN_REFAULT;
+	}
+
+	err = drm_bo_wait(bo, 0, 1, 0, 1);
+	if (err) {
+		ret = (err != -EAGAIN) ? NOPFN_SIGBUS : NOPFN_REFAULT;
+		bo->priv_flags &= ~_DRM_BO_FLAG_UNLOCKED;
+		goto out_unlock;
+	}
+
+	bo->priv_flags &= ~_DRM_BO_FLAG_UNLOCKED;
+
+	/*
+	 * If buffer happens to be in a non-mappable location,
+	 * move it to a mappable.
+	 */
+
+	if (!(bo->mem.flags & DRM_BO_FLAG_MAPPABLE)) {
+		uint32_t new_flags = bo->mem.proposed_flags |
+			DRM_BO_FLAG_MAPPABLE |
+			DRM_BO_FLAG_FORCE_MAPPABLE;
+		err = drm_bo_move_buffer(bo, new_flags, 0, 0);
+		if (err) {
+			ret = (err != -EAGAIN) ? NOPFN_SIGBUS : NOPFN_REFAULT;
+			goto out_unlock;
+		}
+	}
+
+	err = drm_bo_pci_offset(dev, &bo->mem, &bus_base, &bus_offset,
+				&bus_size);
+
+	if (err) {
+		ret = NOPFN_SIGBUS;
+		goto out_unlock;
+	}
+
+	page_offset = (address - vma->vm_start) >> PAGE_SHIFT;
+
+	if (bus_size) {
+		struct drm_mem_type_manager *man = &dev->bm.man[bo->mem.mem_type];
+
+		pfn = ((bus_base + bus_offset) >> PAGE_SHIFT) + page_offset;
+		vma->vm_page_prot = drm_io_prot(man->drm_bus_maptype, vma);
+	} else {
+		ttm = bo->ttm;
+
+		drm_ttm_fixup_caching(ttm);
+		page = drm_ttm_get_page(ttm, page_offset);
+		if (!page) {
+			ret = NOPFN_OOM;
+			goto out_unlock;
+		}
+		pfn = page_to_pfn(page);
+		vma->vm_page_prot = (bo->mem.flags & DRM_BO_FLAG_CACHED) ?
+			vm_get_page_prot(vma->vm_flags) :
+			drm_io_prot(_DRM_TTM, vma);
+	}
+
+	err = vm_insert_pfn(vma, address, pfn);
+	if (err) {
+		ret = (err != -EAGAIN) ? NOPFN_OOM : NOPFN_REFAULT;
+		goto out_unlock;
+	}
+out_unlock:
+	BUG_ON(bo->priv_flags & _DRM_BO_FLAG_UNLOCKED);
+	mutex_unlock(&bo->mutex);
+	drm_bo_read_unlock(&dev->bm.bm_lock);
+	return ret;
+}
+#endif
+#endif