[PATCH 4.14 100/199] drm: Remove PageReserved manipulation from drm_pci_alloc

From: Greg Kroah-Hartman
Date: Wed Apr 22 2020 - 06:12:37 EST


From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>

[ Upstream commit ea36ec8623f56791c6ff6738d0509b7920f85220 ]

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@xxxxxxxxxxxxxxx>
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
Bug: 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@xxxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v4.5+
Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20200202171635.4039044-1-chris@xxxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/drm_pci.c | 25 ++-----------------------
1 file changed, 2 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c
index 1235c9877d6f1..2078d7706a67b 100644
--- a/drivers/gpu/drm/drm_pci.c
+++ b/drivers/gpu/drm/drm_pci.c
@@ -46,8 +46,6 @@
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.
@@ -61,22 +59,13 @@ drm_dma_handle_t *drm_pci_alloc(struct drm_device * dev, size_t size, size_t ali
return NULL;

dmah->size = size;
- dmah->vaddr = dma_alloc_coherent(&dev->pdev->dev, size, &dmah->busaddr, GFP_KERNEL | __GFP_COMP);
+ dmah->vaddr = dma_alloc_coherent(&dev->pdev->dev, size, &dmah->busaddr, GFP_KERNEL);

if (dmah->vaddr == NULL) {
kfree(dmah);
return NULL;
}

- memset(dmah->vaddr, 0, size);
-
- /* 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;
}

@@ -89,19 +78,9 @@ 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);
- }
}

/**
--
2.20.1