[PATCH] drm: Remove PageReserved manipulation from drm_pci_alloc - Linux-stable-mirror

2 Feb 2020

drm_pci_alloc/drm_pci_free are very thin wrappers around the core dma
facilities, and we have no special reason within the drm layer to behave
differently. In particular, since
commit de09d31dd38a50fdce106c15abd68432eebbd014
Author: Kirill A. Shutemov kirill.shutemov@linux.intel.com
Date:   Fri Jan 15 16:51:42 2016 -0800
page-flags: define PG_reserved behavior on compound pages
As far as I can see there's no users of PG_reserved on compound pages.
    Let's use PF_NO_COMPOUND here.
it has been illegal to combine GFP_COMP with SetPageReserved, so lets
stop doing both and leave the dma layer to its own devices.
Reported-by: Taketo Kabe
Closes: https://gitlab.freedesktop.org/drm/intel/issues/1027
Fixes: de09d31dd38a ("page-flags: define PG_reserved behavior on compound pages")
Signed-off-by: Chris Wilson chris@chris-wilson.co.uk
Cc: stable@vger.kernel.org # v4.5+
---
 drivers/gpu/drm/drm_pci.c | 23 ++---------------------
 1 file changed, 2 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c
index f2e43d341980..d16dac4325f9 100644
--- a/drivers/gpu/drm/drm_pci.c
+++ b/drivers/gpu/drm/drm_pci.c
@@ -51,8 +51,6 @@
 drm_dma_handle_t *drm_pci_alloc(struct drm_device * dev, size_t size, size_t align)
 {
    drm_dma_handle_t *dmah;
-	unsigned long addr;
-	size_t sz;
/* pci_alloc_consistent only guarantees alignment to the smallest
     * PAGE_SIZE order which is greater than or equal to the requested size.
@@ -68,20 +66,13 @@ drm_dma_handle_t *drm_pci_alloc(struct drm_device * dev, size_t size, size_t ali
    dmah->size = size;
    dmah->vaddr = dma_alloc_coherent(&dev->pdev->dev, size,
    				 &dmah->busaddr,
-					 GFP_KERNEL | __GFP_COMP);
+					 GFP_KERNEL);
if (dmah->vaddr == NULL) {
    	kfree(dmah);
    	return NULL;
    }
-	/* XXX - Is virt_to_page() legal for consistent mem? */
-	/* Reserve */
-	for (addr = (unsigned long)dmah->vaddr, sz = size;
-	     sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
-		SetPageReserved(virt_to_page((void *)addr));
-	}
-
    return dmah;
 }
@@ -94,19 +85,9 @@ EXPORT_SYMBOL(drm_pci_alloc);
  */
 void __drm_legacy_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
 {
-	unsigned long addr;
-	size_t sz;
-
-	if (dmah->vaddr) {
-		/* XXX - Is virt_to_page() legal for consistent mem? */
-		/* Unreserve */
-		for (addr = (unsigned long)dmah->vaddr, sz = dmah->size;
-		     sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
-			ClearPageReserved(virt_to_page((void *)addr));
-		}
+	if (dmah->vaddr)
    	dma_free_coherent(&dev->pdev->dev, dmah->size, dmah->vaddr,
    			  dmah->busaddr);
-	}
 }
/**
-- 
2.25.0


    