Add ioremap_pud_enabled() and ioremap_pmd_enabled(), which return 1 when I/O mappings of pud/pmd are enabled on the kernel.
ioremap_huge_init() calls arch_ioremap_pud_supported() and arch_ioremap_pmd_supported() to initialize the capabilities. A new kernel option "nohugeiomap" is also added, so that user can disable the huge I/O map capabilities when necessary. Signed-off-by: Toshi Kani <[email protected]> --- Documentation/kernel-parameters.txt | 2 ++ include/linux/io.h | 7 ++++++ init/main.c | 2 ++ lib/ioremap.c | 38 +++++++++++++++++++++++++++++++++++ 4 files changed, 49 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 176d4fe..1872b46 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2304,6 +2304,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. register save and restore. The kernel will only save legacy floating-point registers on task switch. + nohugeiomap [KNL,x86] Disable kernel huge I/O mappings. + noxsave [BUGS=X86] Disables x86 extended register state save and restore using xsave. The kernel will fallback to enabling legacy floating-point and sse state. diff --git a/include/linux/io.h b/include/linux/io.h index fa02e55..9acc588a 100644 --- a/include/linux/io.h +++ b/include/linux/io.h @@ -38,6 +38,13 @@ static inline int ioremap_page_range(unsigned long addr, unsigned long end, } #endif +void __init ioremap_huge_init(void); + +#ifdef CONFIG_HUGE_IOMAP +int arch_ioremap_pud_supported(void); +int arch_ioremap_pmd_supported(void); +#endif + /* * Managed iomap interface */ diff --git a/init/main.c b/init/main.c index 61b99376..9f871ac 100644 --- a/init/main.c +++ b/init/main.c @@ -80,6 +80,7 @@ #include <linux/list.h> #include <linux/integrity.h> #include <linux/proc_ns.h> +#include <linux/io.h> #include <asm/io.h> #include <asm/bugs.h> @@ -497,6 +498,7 @@ static void __init mm_init(void) percpu_init_late(); pgtable_init(); vmalloc_init(); + ioremap_huge_init(); } asmlinkage __visible void __init start_kernel(void) diff --git a/lib/ioremap.c b/lib/ioremap.c index 0c9216c..cafd83e 100644 --- a/lib/ioremap.c +++ b/lib/ioremap.c @@ -13,6 +13,44 @@ #include <asm/cacheflush.h> #include <asm/pgtable.h> +#ifdef CONFIG_HUGE_IOMAP +int __read_mostly ioremap_pud_capable; +int __read_mostly ioremap_pmd_capable; +int __read_mostly ioremap_huge_disabled; + +static int __init set_nohugeiomap(char *str) +{ + ioremap_huge_disabled = 1; + return 0; +} +early_param("nohugeiomap", set_nohugeiomap); + +void __init ioremap_huge_init(void) +{ + if (!ioremap_huge_disabled) { + if (arch_ioremap_pud_supported()) + ioremap_pud_capable = 1; + if (arch_ioremap_pmd_supported()) + ioremap_pmd_capable = 1; + } +} + +static inline int ioremap_pud_enabled(void) +{ + return ioremap_pud_capable; +} + +static inline int ioremap_pmd_enabled(void) +{ + return ioremap_pmd_capable; +} + +#else /* !CONFIG_HUGE_IOMAP */ +void __init ioremap_huge_init(void) { } +static inline int ioremap_pud_enabled(void) { return 0; } +static inline int ioremap_pmd_enabled(void) { return 0; } +#endif /* CONFIG_HUGE_IOMAP */ + static int ioremap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
