On 10/01/09 12:07, Jeremy Fitzhardinge wrote:
> Could modify drm_vmalloc_dma to do the vmalloc "manually":
>
> 1. call __get_vm_area to reserve a chunk of vmalloc address space
> 2. allocate a bunch of individual pages with dma_alloc_coherent
> 3. insert them into the vmalloc mapping with map_vm_area
>
> That will guarantee a normal-looking vmalloc area with device-friendly
> pages that subsequent pci_map_page operations will use as-is.
>
Like this (untested):
diff --git a/drivers/gpu/drm/drm_scatter.c b/drivers/gpu/drm/drm_scatter.c
index c7823c8..73bfa63 100644
--- a/drivers/gpu/drm/drm_scatter.c
+++ b/drivers/gpu/drm/drm_scatter.c
@@ -32,16 +32,60 @@
*/
#include <linux/vmalloc.h>
+#include
<linux/mm.h>
#include "drmP.h"
#define DEBUG_SCATTER 0
-static inline void *drm_vmalloc_dma(unsigned long size)
+static inline void *drm_vmalloc_dma(struct drm_device *drmdev, unsigned long size)
{
#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL | _PAGE_NO_CACHE);
#else
- return vmalloc_32(size);
+ struct device *dev = &drmdev->pdev->dev;
+ struct vm_struct *vma;
+ struct page **pages;
+ const int npages = PFN_UP(size);
+ int i;
+
+ pages = kmalloc(npages * sizeof(*pages), GFP_KERNEL);
+ if (!pages)
+ goto out_free_pagearr;
+
+ vma = __get_vm_area(size, VM_ALLOC, VMALLOC_START,
VMALLOC_END);
+ if (!vma)
+ goto out_release_vma;
+
+ for (i = 0; i < npages; i++) {
+ dma_addr_t phys;
+ void *addr;
+ addr = dma_alloc_coherent(dev, PAGE_SIZE, &phys, GFP_KERNEL);
+ if (addr == NULL)
+ goto out_free_pages;
+
+ pages[i] = virt_to_page(addr);
+ }
+
+ if (map_vm_area(vma, PAGE_KERNEL, &pages))
+ goto out_free_pages;
+
+ kfree(pages);
+
+ return vma->addr;
+
+out_free_pages:
+ while(i > 0) {
+
void *addr = page_address(pages[--i]);
+ dma_free_coherent(dev, PAGE_SIZE, addr, virt_to_bus(addr));
+ }
+
+out_release_vma:
+ vunmap(vma->addr);
+
+out_free_pagearr:
+ kfree(pages);
+
+ return NULL;
#endif
}
@@ -107,7 +151,7 @@ int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request)
}
memset((void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr));
- entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT);
+ entry->virtual = drm_vmalloc_dma(dev, pages << PAGE_SHIFT);
if (!entry->virtual) {
kfree(entry->busaddr);
kfree(entry->pagelist);
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