diff options
| -rw-r--r-- | arch/mips/mm/ioremap.c | 37 |
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; } /* |