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

(cherry picked from commit 10d5b037b85706037df89bf0275436797e4eb559)

3 files changed, 120 insertions, 17 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
diff --git a/linux-core/drm_compat.h b/linux-core/drm_compat.h
index cfa4fc6d..19dc1f67 100644
--- a/linux-core/drm_compat.h
+++ b/linux-core/drm_compat.h
@@ -319,6 +319,9 @@ extern int drm_bo_map_bound(struct vm_area_struct *vma);
 /* fixme when functions are upstreamed - upstreamed for 2.6.23 */
 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23))
 #define DRM_IDR_COMPAT_FN
+#define DRM_NO_FAULT
+extern unsigned long drm_bo_vm_nopfn(struct vm_area_struct *vma,
+				     unsigned long address);
 #endif
 #ifdef DRM_IDR_COMPAT_FN
 int idr_for_each(struct idr *idp,
diff --git a/linux-core/drm_vm.c b/linux-core/drm_vm.c
index 6618c0ae..0d5242d3 100644
--- a/linux-core/drm_vm.c
+++ b/linux-core/drm_vm.c
@@ -685,8 +685,8 @@ EXPORT_SYMBOL(drm_mmap);
  * \c Pagefault method for buffer objects.
  *
  * \param vma Virtual memory area.
- * \param address File offset.
- * \return Error or refault. The pfn is manually inserted.
+ * \param vmf vm fault data
+ * \return Error or VM_FAULT_NOPAGE:. The pfn is manually inserted.
  *
  * It's important that pfns are inserted while holding the bo->mutex lock.
  * otherwise we might race with unmap_mapping_range() which is always
@@ -699,8 +699,8 @@ EXPORT_SYMBOL(drm_mmap);
  */
 
 #ifdef DRM_FULL_MM_COMPAT
-static unsigned long drm_bo_vm_nopfn(struct vm_area_struct *vma,
-				     unsigned long address)
+static int drm_bo_vm_fault(struct vm_area_struct *vma,
+				     struct vm_fault *vmf)
 {
 	struct drm_buffer_object *bo = (struct drm_buffer_object *) vma->vm_private_data;
 	unsigned long page_offset;
@@ -712,25 +712,22 @@ static unsigned long drm_bo_vm_nopfn(struct vm_area_struct *vma,
 	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;
+	unsigned long ret = VM_FAULT_NOPAGE;
 
 	dev = bo->dev;
 	err = drm_bo_read_lock(&dev->bm.bm_lock, 1);
 	if (err)
-		return NOPFN_REFAULT;
+		return VM_FAULT_NOPAGE;
 
 	err = mutex_lock_interruptible(&bo->mutex);
 	if (err) {
 		drm_bo_read_unlock(&dev->bm.bm_lock);
-		return NOPFN_REFAULT;
+		return VM_FAULT_NOPAGE;
 	}
 
 	err = drm_bo_wait(bo, 0, 1, 0, 1);
 	if (err) {
-		ret = (err != -EAGAIN) ? NOPFN_SIGBUS : NOPFN_REFAULT;
+		ret = (err != -EAGAIN) ? VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
 		bo->priv_flags &= ~_DRM_BO_FLAG_UNLOCKED;
 		goto out_unlock;
 	}
@@ -748,7 +745,7 @@ static unsigned long drm_bo_vm_nopfn(struct vm_area_struct *vma,
 			DRM_BO_FLAG_FORCE_MAPPABLE;
 		err = drm_bo_move_buffer(bo, new_flags, 0, 0);
 		if (err) {
-			ret = (err != -EAGAIN) ? NOPFN_SIGBUS : NOPFN_REFAULT;
+			ret = (err != -EAGAIN) ? VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
 			goto out_unlock;
 		}
 	}
@@ -757,11 +754,11 @@ static unsigned long drm_bo_vm_nopfn(struct vm_area_struct *vma,
 				&bus_size);
 
 	if (err) {
-		ret = NOPFN_SIGBUS;
+		ret = VM_FAULT_SIGBUS;
 		goto out_unlock;
 	}
 
-	page_offset = (address - vma->vm_start) >> PAGE_SHIFT;
+	page_offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >> PAGE_SHIFT;
 
 	if (bus_size) {
 		struct drm_mem_type_manager *man = &dev->bm.man[bo->mem.mem_type];
@@ -774,7 +771,7 @@ static unsigned long drm_bo_vm_nopfn(struct vm_area_struct *vma,
 		drm_ttm_fixup_caching(ttm);
 		page = drm_ttm_get_page(ttm, page_offset);
 		if (!page) {
-			ret = NOPFN_OOM;
+			ret = VM_FAULT_OOM;
 			goto out_unlock;
 		}
 		pfn = page_to_pfn(page);
@@ -783,9 +780,9 @@ static unsigned long drm_bo_vm_nopfn(struct vm_area_struct *vma,
 			drm_io_prot(_DRM_TTM, vma);
 	}
 
-	err = vm_insert_pfn(vma, address, pfn);
+	err = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
 	if (err) {
-		ret = (err != -EAGAIN) ? NOPFN_OOM : NOPFN_REFAULT;
+		ret = (err != -EAGAIN) ? VM_FAULT_OOM : VM_FAULT_NOPAGE;
 		goto out_unlock;
 	}
 out_unlock:
@@ -849,8 +846,12 @@ static void drm_bo_vm_close(struct vm_area_struct *vma)
 
 static struct vm_operations_struct drm_bo_vm_ops = {
 #ifdef DRM_FULL_MM_COMPAT
+#ifdef DRM_NO_FAULT
 	.nopfn = drm_bo_vm_nopfn,
 #else
+	.fault = drm_bo_vm_fault,
+#endif
+#else
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19))
 	.nopfn = drm_bo_vm_nopfn,
 #else