From 0ddab1d2ed664c85c95488eef569786a84aedf37 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Tue, 14 Apr 2015 15:47:20 -0700 Subject: [PATCH] lib/ioremap.c: add huge I/O map capability interfaces Add ioremap_pud_enabled() and ioremap_pmd_enabled(), which return 1 when I/O mappings with pud/pmd are enabled on the kernel. ioremap_huge_init() calls arch_ioremap_pud_supported() and arch_ioremap_pmd_supported() to initialize the capabilities at boot-time. 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 Cc: "H. Peter Anvin" Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Arnd Bergmann Cc: Dave Hansen Cc: Robert Elliott Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-parameters.txt | 2 ++ arch/Kconfig | 3 +++ include/linux/io.h | 8 +++++++ init/main.c | 2 ++ lib/ioremap.c | 37 +++++++++++++++++++++++++++++ 5 files changed, 52 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 71eecb263250..b1fa70907ccf 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2323,6 +2323,8 @@ 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/arch/Kconfig b/arch/Kconfig index a9c95d36ba70..c88c23f0a1da 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -446,6 +446,9 @@ config HAVE_IRQ_TIME_ACCOUNTING config HAVE_ARCH_TRANSPARENT_HUGEPAGE bool +config HAVE_ARCH_HUGE_VMAP + bool + config HAVE_ARCH_SOFT_DIRTY bool diff --git a/include/linux/io.h b/include/linux/io.h index fa02e55e5a2e..4cc299c598e0 100644 --- a/include/linux/io.h +++ b/include/linux/io.h @@ -38,6 +38,14 @@ static inline int ioremap_page_range(unsigned long addr, unsigned long end, } #endif +#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP +void __init ioremap_huge_init(void); +int arch_ioremap_pud_supported(void); +int arch_ioremap_pmd_supported(void); +#else +static inline void ioremap_huge_init(void) { } +#endif + /* * Managed iomap interface */ diff --git a/init/main.c b/init/main.c index 4a6974e67839..f6dd8fe1f22c 100644 --- a/init/main.c +++ b/init/main.c @@ -80,6 +80,7 @@ #include #include #include +#include #include #include @@ -484,6 +485,7 @@ 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 0c9216c48762..2008652c9a1f 100644 --- a/lib/ioremap.c +++ b/lib/ioremap.c @@ -13,6 +13,43 @@ #include #include +#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP +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_HAVE_ARCH_HUGE_VMAP */ +static inline int ioremap_pud_enabled(void) { return 0; } +static inline int ioremap_pmd_enabled(void) { return 0; } +#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ + static int ioremap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { -- 2.34.1