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-rw-r--r--arch/mips/mm/ioremap.c37
1 files changed, 25 insertions, 12 deletions
diff --git a/arch/mips/mm/ioremap.c b/arch/mips/mm/ioremap.c
index 1986e09fb457..1601d90b087b 100644
--- a/arch/mips/mm/ioremap.c
+++ b/arch/mips/mm/ioremap.c
@@ -9,6 +9,7 @@
#include <linux/export.h>
#include <asm/addrspace.h>
#include <asm/byteorder.h>
+#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
@@ -98,6 +99,20 @@ static int remap_area_pages(unsigned long address, phys_addr_t phys_addr,
return error;
}
+static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages,
+ void *arg)
+{
+ unsigned long i;
+
+ for (i = 0; i < nr_pages; i++) {
+ if (pfn_valid(start_pfn + i) &&
+ !PageReserved(pfn_to_page(start_pfn + i)))
+ return 1;
+ }
+
+ return 0;
+}
+
/*
* Generic mapping function (not visible outside):
*/
@@ -116,8 +131,8 @@ static int remap_area_pages(unsigned long address, phys_addr_t phys_addr,
void __iomem * __ioremap(phys_addr_t phys_addr, phys_addr_t size, unsigned long flags)
{
+ unsigned long offset, pfn, last_pfn;
struct vm_struct * area;
- unsigned long offset;
phys_addr_t last_addr;
void * addr;
@@ -137,18 +152,16 @@ void __iomem * __ioremap(phys_addr_t phys_addr, phys_addr_t size, unsigned long
return (void __iomem *) CKSEG1ADDR(phys_addr);
/*
- * Don't allow anybody to remap normal RAM that we're using..
+ * Don't allow anybody to remap RAM that may be allocated by the page
+ * allocator, since that could lead to races & data clobbering.
*/
- if (phys_addr < virt_to_phys(high_memory)) {
- char *t_addr, *t_end;
- struct page *page;
-
- t_addr = __va(phys_addr);
- t_end = t_addr + (size - 1);
-
- for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++)
- if(!PageReserved(page))
- return NULL;
+ pfn = PFN_DOWN(phys_addr);
+ last_pfn = PFN_DOWN(last_addr);
+ if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
+ __ioremap_check_ram) == 1) {
+ WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n",
+ &phys_addr, &last_addr);
+ return NULL;
}
/*