1 files changed, 65 insertions, 104 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 0c4576cbafcf..6dacff49c1cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -42,6 +42,8 @@
 #include <linux/uaccess.h>
 #include <linux/mem_encrypt.h>
 
+#define TTM_BO_VM_NUM_PREFAULT 16
+
 static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
 				struct vm_fault *vmf)
 {
@@ -104,30 +106,25 @@ static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo,
 		+ page_offset;
 }
 
-/**
- * ttm_bo_vm_reserve - Reserve a buffer object in a retryable vm callback
- * @bo: The buffer object
- * @vmf: The fault structure handed to the callback
- *
- * vm callbacks like fault() and *_mkwrite() allow for the mm_sem to be dropped
- * during long waits, and after the wait the callback will be restarted. This
- * is to allow other threads using the same virtual memory space concurrent
- * access to map(), unmap() completely unrelated buffer objects. TTM buffer
- * object reservations sometimes wait for GPU and should therefore be
- * considered long waits. This function reserves the buffer object interruptibly
- * taking this into account. Starvation is avoided by the vm system not
- * allowing too many repeated restarts.
- * This function is intended to be used in customized fault() and _mkwrite()
- * handlers.
- *
- * Return:
- *    0 on success and the bo was reserved.
- *    VM_FAULT_RETRY if blocking wait.
- *    VM_FAULT_NOPAGE if blocking wait and retrying was not allowed.
- */
-vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
-			     struct vm_fault *vmf)
+static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
 {
+	struct vm_area_struct *vma = vmf->vma;
+	struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
+	    vma->vm_private_data;
+	struct ttm_bo_device *bdev = bo->bdev;
+	unsigned long page_offset;
+	unsigned long page_last;
+	unsigned long pfn;
+	struct ttm_tt *ttm = NULL;
+	struct page *page;
+	int err;
+	int i;
+	vm_fault_t ret = VM_FAULT_NOPAGE;
+	unsigned long address = vmf->address;
+	struct ttm_mem_type_manager *man =
+		&bdev->man[bo->mem.mem_type];
+	struct vm_area_struct cvma;
+
 	/*
 	 * Work around locking order reversal in fault / nopfn
 	 * between mmap_sem and bo_reserve: Perform a trylock operation
@@ -154,55 +151,14 @@ vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
 		return VM_FAULT_NOPAGE;
 	}
 
-	return 0;
-}
-EXPORT_SYMBOL(ttm_bo_vm_reserve);
-
-/**
- * ttm_bo_vm_fault_reserved - TTM fault helper
- * @vmf: The struct vm_fault given as argument to the fault callback
- * @prot: The page protection to be used for this memory area.
- * @num_prefault: Maximum number of prefault pages. The caller may want to
- * specify this based on madvice settings and the size of the GPU object
- * backed by the memory.
- *
- * This function inserts one or more page table entries pointing to the
- * memory backing the buffer object, and then returns a return code
- * instructing the caller to retry the page access.
- *
- * Return:
- *   VM_FAULT_NOPAGE on success or pending signal
- *   VM_FAULT_SIGBUS on unspecified error
- *   VM_FAULT_OOM on out-of-memory
- *   VM_FAULT_RETRY if retryable wait
- */
-vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
-				    pgprot_t prot,
-				    pgoff_t num_prefault)
-{
-	struct vm_area_struct *vma = vmf->vma;
-	struct vm_area_struct cvma = *vma;
-	struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
-	    vma->vm_private_data;
-	struct ttm_bo_device *bdev = bo->bdev;
-	unsigned long page_offset;
-	unsigned long page_last;
-	unsigned long pfn;
-	struct ttm_tt *ttm = NULL;
-	struct page *page;
-	int err;
-	pgoff_t i;
-	vm_fault_t ret = VM_FAULT_NOPAGE;
-	unsigned long address = vmf->address;
-	struct ttm_mem_type_manager *man =
-		&bdev->man[bo->mem.mem_type];
-
 	/*
 	 * Refuse to fault imported pages. This should be handled
 	 * (if at all) by redirecting mmap to the exporter.
 	 */
-	if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG))
-		return VM_FAULT_SIGBUS;
+	if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) {
+		ret = VM_FAULT_SIGBUS;
+		goto out_unlock;
+	}
 
 	if (bdev->driver->fault_reserve_notify) {
 		struct dma_fence *moving = dma_fence_get(bo->moving);
@@ -213,9 +169,11 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 			break;
 		case -EBUSY:
 		case -ERESTARTSYS:
-			return VM_FAULT_NOPAGE;
+			ret = VM_FAULT_NOPAGE;
+			goto out_unlock;
 		default:
-			return VM_FAULT_SIGBUS;
+			ret = VM_FAULT_SIGBUS;
+			goto out_unlock;
 		}
 
 		if (bo->moving != moving) {
@@ -231,12 +189,21 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 	 * move.
 	 */
 	ret = ttm_bo_vm_fault_idle(bo, vmf);
-	if (unlikely(ret != 0))
-		return ret;
+	if (unlikely(ret != 0)) {
+		if (ret == VM_FAULT_RETRY &&
+		    !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
+			/* The BO has already been unreserved. */
+			return ret;
+		}
+
+		goto out_unlock;
+	}
 
 	err = ttm_mem_io_lock(man, true);
-	if (unlikely(err != 0))
-		return VM_FAULT_NOPAGE;
+	if (unlikely(err != 0)) {
+		ret = VM_FAULT_NOPAGE;
+		goto out_unlock;
+	}
 	err = ttm_mem_io_reserve_vm(bo);
 	if (unlikely(err != 0)) {
 		ret = VM_FAULT_SIGBUS;
@@ -253,8 +220,18 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 		goto out_io_unlock;
 	}
 
-	cvma.vm_page_prot = ttm_io_prot(bo->mem.placement, prot);
-	if (!bo->mem.bus.is_iomem) {
+	/*
+	 * Make a local vma copy to modify the page_prot member
+	 * and vm_flags if necessary. The vma parameter is protected
+	 * by mmap_sem in write mode.
+	 */
+	cvma = *vma;
+	cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags);
+
+	if (bo->mem.bus.is_iomem) {
+		cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
+						cvma.vm_page_prot);
+	} else {
 		struct ttm_operation_ctx ctx = {
 			.interruptible = false,
 			.no_wait_gpu = false,
@@ -263,21 +240,24 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 		};
 
 		ttm = bo->ttm;
-		if (ttm_tt_populate(bo->ttm, &ctx)) {
+		cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
+						cvma.vm_page_prot);
+
+		/* Allocate all page at once, most common usage */
+		if (ttm_tt_populate(ttm, &ctx)) {
 			ret = VM_FAULT_OOM;
 			goto out_io_unlock;
 		}
-	} else {
-		/* Iomem should not be marked encrypted */
-		cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot);
 	}
 
 	/*
 	 * Speculatively prefault a number of pages. Only error on
 	 * first page.
 	 */
-	for (i = 0; i < num_prefault; ++i) {
+	for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
 		if (bo->mem.bus.is_iomem) {
+			/* Iomem should not be marked encrypted */
+			cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot);
 			pfn = ttm_bo_io_mem_pfn(bo, page_offset);
 		} else {
 			page = ttm->pages[page_offset];
@@ -315,26 +295,7 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 	ret = VM_FAULT_NOPAGE;
 out_io_unlock:
 	ttm_mem_io_unlock(man);
-	return ret;
-}
-EXPORT_SYMBOL(ttm_bo_vm_fault_reserved);
-
-static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
-{
-	struct vm_area_struct *vma = vmf->vma;
-	pgprot_t prot;
-	struct ttm_buffer_object *bo = vma->vm_private_data;
-	vm_fault_t ret;
-
-	ret = ttm_bo_vm_reserve(bo, vmf);
-	if (ret)
-		return ret;
-
-	prot = vm_get_page_prot(vma->vm_flags);
-	ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT);
-	if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
-		return ret;
-
+out_unlock:
 	reservation_object_unlock(bo->resv);
 	return ret;
 }
@@ -434,7 +395,7 @@ static int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
 	return ret;
 }
 
-const struct vm_operations_struct ttm_bo_vm_ops = {
+static const struct vm_operations_struct ttm_bo_vm_ops = {
 	.fault = ttm_bo_vm_fault,
 	.open = ttm_bo_vm_open,
 	.close = ttm_bo_vm_close,
@@ -487,7 +448,7 @@ int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 	if (unlikely(ret != 0))
 		goto out_unref;
 
-	vma->vm_ops = bdev->vm_ops;
+	vma->vm_ops = &ttm_bo_vm_ops;
 
 	/*
 	 * Note: We're transferring the bo reference to
@@ -519,7 +480,7 @@ int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 
 	ttm_bo_get(bo);
 
-	vma->vm_ops = bo->bdev->vm_ops;
+	vma->vm_ops = &ttm_bo_vm_ops;
 	vma->vm_private_data = bo;
 	vma->vm_flags |= VM_MIXEDMAP;
 	vma->vm_flags |= VM_IO | VM_DONTEXPAND;