From 0ddab1d2ed664c85c95488eef569786a84aedf37 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Tue, 14 Apr 2015 15:47:20 -0700 Subject: 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 --- lib/ioremap.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'lib/ioremap.c') 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) { -- cgit v1.2.3 From e61ce6ade404ef17bd63d62bec78e29047a47b47 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Tue, 14 Apr 2015 15:47:23 -0700 Subject: mm: change ioremap to set up huge I/O mappings ioremap_pud_range() and ioremap_pmd_range() are changed to create huge I/O mappings when their capability is enabled, and a request meets required conditions -- both virtual & physical addresses are aligned by their huge page size, and a requested range fufills their huge page size. When pud_set_huge() or pmd_set_huge() returns zero, i.e. no-operation is performed, the code simply falls back to the next level. The changes are only enabled when CONFIG_HAVE_ARCH_HUGE_VMAP is defined on the architecture. 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 --- lib/ioremap.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'lib/ioremap.c') diff --git a/lib/ioremap.c b/lib/ioremap.c index 2008652c9a1f..be249062ba6e 100644 --- a/lib/ioremap.c +++ b/lib/ioremap.c @@ -80,6 +80,14 @@ static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr, return -ENOMEM; do { next = pmd_addr_end(addr, end); + + if (ioremap_pmd_enabled() && + ((next - addr) == PMD_SIZE) && + IS_ALIGNED(phys_addr + addr, PMD_SIZE)) { + if (pmd_set_huge(pmd, phys_addr + addr, prot)) + continue; + } + if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot)) return -ENOMEM; } while (pmd++, addr = next, addr != end); @@ -98,6 +106,14 @@ static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr, return -ENOMEM; do { next = pud_addr_end(addr, end); + + if (ioremap_pud_enabled() && + ((next - addr) == PUD_SIZE) && + IS_ALIGNED(phys_addr + addr, PUD_SIZE)) { + if (pud_set_huge(pud, phys_addr + addr, prot)) + continue; + } + if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot)) return -ENOMEM; } while (pud++, addr = next, addr != end); -- cgit v1.2.3 From 6b6378355b925050eb6fa966742d8c2d65ff0d83 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Tue, 14 Apr 2015 15:47:32 -0700 Subject: x86, mm: support huge KVA mappings on x86 Implement huge KVA mapping interfaces on x86. On x86, MTRRs can override PAT memory types with a 4KB granularity. When using a huge page, MTRRs can override the memory type of the huge page, which may lead a performance penalty. The processor can also behave in an undefined manner if a huge page is mapped to a memory range that MTRRs have mapped with multiple different memory types. Therefore, the mapping code falls back to use a smaller page size toward 4KB when a mapping range is covered by non-WB type of MTRRs. The WB type of MTRRs has no affect on the PAT memory types. pud_set_huge() and pmd_set_huge() call mtrr_type_lookup() to see if a given range is covered by MTRRs. MTRR_TYPE_WRBACK indicates that the range is either covered by WB or not covered and the MTRR default value is set to WB. 0xFF indicates that MTRRs are disabled. HAVE_ARCH_HUGE_VMAP is selected when X86_64 or X86_32 with X86_PAE is set. X86_32 without X86_PAE is not supported since such config can unlikey be benefited from this feature, and there was an issue found in testing. [fengguang.wu@intel.com: ioremap_pud_capable can be static] 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: Fengguang Wu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/ioremap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'lib/ioremap.c') diff --git a/lib/ioremap.c b/lib/ioremap.c index be249062ba6e..86c8911b0e3a 100644 --- a/lib/ioremap.c +++ b/lib/ioremap.c @@ -14,9 +14,9 @@ #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 __read_mostly ioremap_pud_capable; +static int __read_mostly ioremap_pmd_capable; +static int __read_mostly ioremap_huge_disabled; static int __init set_nohugeiomap(char *str) { -- cgit v1.2.3