This patch uses the optimized ioresource lookup, "region_is_ram", for
the ioremap function. If the region is not found, it falls back to the
"page_is_ram" function. If it is found and it is RAM, then the usual
warning message is issued, and the ioremap operation is aborted.
Otherwise, the ioremap operation continues.
Signed-off-by: Mike Travis <travis@xxxxxxx>
Acked-by: Alex Thorlton <athorlton@xxxxxxx>
Reviewed-by: Cliff Wickman <cpw@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
v2: slight rearrangement of code
v3: added Cc: stable
---
arch/x86/mm/ioremap.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
--- linux.orig/arch/x86/mm/ioremap.c
+++ linux/arch/x86/mm/ioremap.c
@@ -86,6 +86,7 @@ static void __iomem *__ioremap_caller(re
pgprot_t prot;
int retval;
void __iomem *ret_addr;
+ int ram_region;
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
@@ -108,12 +109,23 @@ static void __iomem *__ioremap_caller(re
/*
* Don't allow anybody to remap normal RAM that we're using..
*/
- pfn = phys_addr >> PAGE_SHIFT;
- last_pfn = last_addr >> PAGE_SHIFT;
- if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
- __ioremap_check_ram) == 1)
+ /* First check if whole region can be identified as RAM or not */
+ ram_region = region_is_ram(phys_addr, size);
+ if (ram_region > 0) {
+ WARN_ONCE(1, "ioremap on RAM at 0x%lx - 0x%lx\n",
+ (unsigned long int)phys_addr,
+ (unsigned long int)last_addr);
return NULL;
+ }
+ /* If could not be identified(-1), check page by page */
+ if (ram_region < 0) {
+ pfn = phys_addr >> PAGE_SHIFT;
+ last_pfn = last_addr >> PAGE_SHIFT;
+ if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
+ __ioremap_check_ram) == 1)
+ return NULL;
+ }
/*
* Mappings have to be page-aligned
*/
--
--
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