[PATCH 05/16] drm: don't mark pages returned from drm_pci_alloc reserved

From: Christoph Hellwig
Date: Fri Jun 14 2019 - 09:54:46 EST


We are not allowed to call virt_to_page on pages returned from
dma_alloc_coherent, as in many cases the virtual address returned
is aactually a kernel direct mapping. Also there generally is no
need to mark dma memory as reserved.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/gpu/drm/drm_bufs.c | 16 +---------------
1 file changed, 1 insertion(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index 7418872d87c6..b640437ce90f 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -77,13 +77,6 @@ drm_dma_handle_t *drm_pci_alloc(struct drm_device * dev, size_t size, size_t ali
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;
}

@@ -97,16 +90,9 @@ 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