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Diffstat (limited to 'drivers')
-rw-r--r--drivers/char/bsr.c25
1 files changed, 19 insertions, 6 deletions
diff --git a/drivers/char/bsr.c b/drivers/char/bsr.c
index 7d9fd8a8dfd..c02db01f736 100644
--- a/drivers/char/bsr.c
+++ b/drivers/char/bsr.c
@@ -27,6 +27,7 @@
#include <linux/cdev.h>
#include <linux/list.h>
#include <linux/mm.h>
+#include <asm/pgtable.h>
#include <asm/io.h>
/*
@@ -118,15 +119,22 @@ static int bsr_mmap(struct file *filp, struct vm_area_struct *vma)
{
unsigned long size = vma->vm_end - vma->vm_start;
struct bsr_dev *dev = filp->private_data;
+ int ret;
- if (size > dev->bsr_len || (size & (PAGE_SIZE-1)))
- return -EINVAL;
-
- vma->vm_flags |= (VM_IO | VM_DONTEXPAND);
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
- if (io_remap_pfn_range(vma, vma->vm_start, dev->bsr_addr >> PAGE_SHIFT,
- size, vma->vm_page_prot))
+ /* check for the case of a small BSR device and map one 4k page for it*/
+ if (dev->bsr_len < PAGE_SIZE && size == PAGE_SIZE)
+ ret = remap_4k_pfn(vma, vma->vm_start, dev->bsr_addr >> 12,
+ vma->vm_page_prot);
+ else if (size <= dev->bsr_len)
+ ret = io_remap_pfn_range(vma, vma->vm_start,
+ dev->bsr_addr >> PAGE_SHIFT,
+ size, vma->vm_page_prot);
+ else
+ return -EINVAL;
+
+ if (ret)
return -EAGAIN;
return 0;
@@ -206,6 +214,11 @@ static int bsr_add_node(struct device_node *bn)
cur->bsr_stride = bsr_stride[i];
cur->bsr_dev = MKDEV(bsr_major, i + total_bsr_devs);
+ /* if we have a bsr_len of > 4k and less then PAGE_SIZE (64k pages) */
+ /* we can only map 4k of it, so only advertise the 4k in sysfs */
+ if (cur->bsr_len > 4096 && cur->bsr_len < PAGE_SIZE)
+ cur->bsr_len = 4096;
+
switch(cur->bsr_bytes) {
case 8:
cur->bsr_type = BSR_8;