[patch 4/4] Xen core patch : /dev/mem calls io_remap_page_range

From: Ian Pratt
Date: Wed Nov 17 2004 - 19:04:59 EST



This patch modifies /dev/mem to call io_remap_page_range rather than
remap_page_range under CONFIG_XEN. (the two definitions are different
under arch xen, unlike most other architectures). This allows the X
server and other programs that use /dev/mem for MMIO to work under
Xen.

Signed-off-by: ian.pratt@xxxxxxxxxxxx

---


diff -Nurp pristine-linux-2.6.9/drivers/char/mem.c linux-2.6.9-xen0/drivers/char/mem.c
--- pristine-linux-2.6.9/drivers/char/mem.c 2004-10-18 22:54:19.000000000 +0100
+++ linux-2.6.9-xen0/drivers/char/mem.c 2004-11-17 00:12:37.000000000 +0000
@@ -26,6 +26,7 @@

#include <asm/uaccess.h>
#include <asm/io.h>
+#include <asm/pgalloc.h>

#ifdef CONFIG_IA64
# include <linux/efi.h>
@@ -42,7 +43,12 @@ extern void tapechar_init(void);
*/
static inline int uncached_access(struct file *file, unsigned long addr)
{
-#if defined(__i386__)
+#ifdef CONFIG_XEN
+ if (file->f_flags & O_SYNC)
+ return 1;
+ /* Xen sets correct MTRR type on non-RAM for us. */
+ return 0;
+#elif defined(__i386__)
/*
* On the PPro and successors, the MTRRs are used to set
* memory types for physical addresses outside main memory,
@@ -210,9 +216,15 @@ static int mmap_mem(struct file * file,
if (uncached)
vma->vm_flags |= VM_IO;

+#if defined(CONFIG_XEN)
+ if (io_remap_page_range(vma, vma->vm_start, offset,
+ vma->vm_end-vma->vm_start, vma->vm_page_prot))
+ return -EAGAIN;
+#else
if (remap_page_range(vma, vma->vm_start, offset, vma->vm_end-vma->vm_start,
vma->vm_page_prot))
return -EAGAIN;
+#endif
return 0;
}

-
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