diff options
| author | Toshi Kani | 2015-04-14 15:47:29 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2015-04-14 16:49:04 -0700 |
| commit | 5d72b4fba40ef4b3f7a1a11d6aacc85d9af81561 (patch) | |
| tree | 94312a459da826b4d0437de9de6f0db856d56c20 /arch | |
| parent | b9820d8f39f816b67112eb7ec5cdc4c1655ff060 (diff) | |
x86, mm: support huge I/O mapping capability I/F
Implement huge I/O mapping capability interfaces for ioremap() on x86.
IOREMAP_MAX_ORDER is defined to PUD_SHIFT on x86/64 and PMD_SHIFT on
x86/32, which overrides the default value defined in <linux/vmalloc.h>.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/page_types.h | 2 | ||||
| -rw-r--r-- | arch/x86/mm/ioremap.c | 23 |
2 files changed, 23 insertions, 2 deletions
diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h index f97fbe3abb67..c7c712f2648b 100644 --- a/arch/x86/include/asm/page_types.h +++ b/arch/x86/include/asm/page_types.h @@ -40,8 +40,10 @@ #ifdef CONFIG_X86_64 #include <asm/page_64_types.h> +#define IOREMAP_MAX_ORDER (PUD_SHIFT) #else #include <asm/page_32_types.h> +#define IOREMAP_MAX_ORDER (PMD_SHIFT) #endif /* CONFIG_X86_64 */ #ifndef __ASSEMBLY__ diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index fdf617c00e2f..5ead4d6cf3a7 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 @@ -326,6 +331,20 @@ 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 |