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authorMike Travis <travis@sgi.com>2014-10-13 15:54:05 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-14 02:18:22 +0200
commit906e36c5c717cc99e622350f533876feed9bffe0 (patch)
tree054826656a5ea90f62373eca18e0b504edc0b59c
parent67cf13ceed89e2c1a967719e98624a20c48dfb5a (diff)
x86: use optimized ioresource lookup in ioremap function
Use 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@sgi.com> Acked-by: Alex Thorlton <athorlton@sgi.com> Reviewed-by: Cliff Wickman <cpw@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Mark Salter <msalter@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/x86/mm/ioremap.c20
1 files changed, 16 insertions, 4 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index baff1da354e0..af78e50ca6ce 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -86,6 +86,7 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
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(resource_size_t phys_addr,
/*
* 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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