diff options
Diffstat (limited to 'arch/x86/mm/ioremap.c')
| -rw-r--r-- | arch/x86/mm/ioremap.c | 37 |
1 files changed, 29 insertions, 8 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index fdf617c00e2f..70e7444c6835 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -67,8 +67,13 @@ static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages, /* * Remap an arbitrary physical address space into the kernel virtual - * address space. Needed when the kernel wants to access high addresses - * directly. + * address space. It transparently creates kernel huge I/O mapping when + * the physical address is aligned by a huge page size (1GB or 2MB) and + * the requested size is at least the huge page size. + * + * NOTE: MTRRs can override PAT memory types with a 4KB granularity. + * Therefore, the mapping code falls back to use a smaller page toward 4KB + * when a mapping range is covered by non-WB type of MTRRs. * * NOTE! We need to allow non-page-aligned mappings too: we will obviously * have to convert them into an offset in a page-aligned mapping, but the @@ -326,24 +331,40 @@ void iounmap(volatile void __iomem *addr) } EXPORT_SYMBOL(iounmap); +int arch_ioremap_pud_supported(void) +{ +#ifdef CONFIG_X86_64 + return cpu_has_gbpages; +#else + return 0; +#endif +} + +int arch_ioremap_pmd_supported(void) +{ + return cpu_has_pse; +} + /* * Convert a physical pointer to a virtual kernel pointer for /dev/mem * access */ void *xlate_dev_mem_ptr(phys_addr_t phys) { - void *addr; - unsigned long start = phys & PAGE_MASK; + unsigned long start = phys & PAGE_MASK; + unsigned long offset = phys & ~PAGE_MASK; + unsigned long vaddr; /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */ if (page_is_ram(start >> PAGE_SHIFT)) return __va(phys); - addr = (void __force *)ioremap_cache(start, PAGE_SIZE); - if (addr) - addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK)); + vaddr = (unsigned long)ioremap_cache(start, PAGE_SIZE); + /* Only add the offset on success and return NULL if the ioremap() failed: */ + if (vaddr) + vaddr += offset; - return addr; + return (void *)vaddr; } void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr) |