[patch 06/18] ieee1394: nopage

From: npiggin
Date: Wed Dec 05 2007 - 02:57:20 EST


Convert ieee1394 from nopage to fault.
Remove redundant vma range checks (correct resource range check is retained).

Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Cc: krh@xxxxxxxxxx
Cc: stefanr@xxxxxxxxxxxxxxxxx
Cc: linux1394-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/ieee1394/dma.c | 39 +++++++++++++++++----------------------
1 file changed, 17 insertions(+), 22 deletions(-)

Index: linux-2.6/drivers/ieee1394/dma.c
===================================================================
--- linux-2.6.orig/drivers/ieee1394/dma.c
+++ linux-2.6/drivers/ieee1394/dma.c
@@ -231,37 +231,32 @@ void dma_region_sync_for_device(struct d

#ifdef CONFIG_MMU

-/* nopage() handler for mmap access */
+/* fault() handler for mmap access */

-static struct page *dma_region_pagefault(struct vm_area_struct *area,
- unsigned long address, int *type)
+static int dma_region_pagefault(struct vm_area_struct *vma,
+ struct vm_fault *vmf)
{
- unsigned long offset;
unsigned long kernel_virt_addr;
- struct page *ret = NOPAGE_SIGBUS;

- struct dma_region *dma = (struct dma_region *)area->vm_private_data;
+ struct dma_region *dma = (struct dma_region *)vma->vm_private_data;

if (!dma->kvirt)
- goto out;
+ goto error;

- if ((address < (unsigned long)area->vm_start) ||
- (address >
- (unsigned long)area->vm_start + (dma->n_pages << PAGE_SHIFT)))
- goto out;
-
- if (type)
- *type = VM_FAULT_MINOR;
- offset = address - area->vm_start;
- kernel_virt_addr = (unsigned long)dma->kvirt + offset;
- ret = vmalloc_to_page((void *)kernel_virt_addr);
- get_page(ret);
- out:
- return ret;
+ if (vmf->pgoff >= dma->n_pages)
+ goto error;
+
+ kernel_virt_addr = (unsigned long)dma->kvirt + (vmf->pgoff << PAGE_SHIFT);
+ vmf->page = vmalloc_to_page((void *)kernel_virt_addr);
+ get_page(vmf->page);
+ return 0;
+
+ error:
+ return VM_FAULT_SIGBUS;
}

static struct vm_operations_struct dma_region_vm_ops = {
- .nopage = dma_region_pagefault,
+ .fault = dma_region_pagefault,
};

/**
@@ -275,7 +270,7 @@ int dma_region_mmap(struct dma_region *d
if (!dma->kvirt)
return -EINVAL;

- /* must be page-aligned */
+ /* must be page-aligned (XXX: comment is wrong, we could allow pgoff) */
if (vma->vm_pgoff != 0)
return -EINVAL;


--

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