From 9e36fda0b359d2a6ae039c3d7e71a04502a77898 Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Fri, 10 Jul 2009 09:57:35 -0700 Subject: x86, pat: Add PAT reserve free to io_mapping* APIs io_mapping_* interfaces were added, mainly for graphics drivers. Make this interface go through the PAT reserve/free, instead of hardcoding WC mapping. This makes sure that there are no aliases due to unconditional WC setting. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/iomap.h | 9 ++++++--- arch/x86/mm/iomap_32.c | 27 +++++++++++++++++++++++++-- include/linux/io-mapping.h | 17 ++++++++++++----- 3 files changed, 43 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/iomap.h b/arch/x86/include/asm/iomap.h index 0e9fe1d9d971..f35eb45d6576 100644 --- a/arch/x86/include/asm/iomap.h +++ b/arch/x86/include/asm/iomap.h @@ -26,13 +26,16 @@ #include #include -int -is_io_mapping_possible(resource_size_t base, unsigned long size); - void * iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot); void iounmap_atomic(void *kvaddr, enum km_type type); +int +iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot); + +void +iomap_free(resource_size_t base, unsigned long size); + #endif /* _ASM_X86_IOMAP_H */ diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c index fe6f84ca121e..84e236ce76ba 100644 --- a/arch/x86/mm/iomap_32.c +++ b/arch/x86/mm/iomap_32.c @@ -21,7 +21,7 @@ #include #include -int is_io_mapping_possible(resource_size_t base, unsigned long size) +static int is_io_mapping_possible(resource_size_t base, unsigned long size) { #if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT) /* There is no way to map greater than 1 << 32 address without PAE */ @@ -30,7 +30,30 @@ int is_io_mapping_possible(resource_size_t base, unsigned long size) #endif return 1; } -EXPORT_SYMBOL_GPL(is_io_mapping_possible); + +int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot) +{ + unsigned long flag = _PAGE_CACHE_WC; + int ret; + + if (!is_io_mapping_possible(base, size)) + return -EINVAL; + + ret = io_reserve_memtype(base, base + size, &flag); + if (ret) + return ret; + + *prot = __pgprot(__PAGE_KERNEL | flag); + return 0; +} +EXPORT_SYMBOL_GPL(iomap_create_wc); + +void +iomap_free(resource_size_t base, unsigned long size) +{ + io_free_memtype(base, base + size); +} +EXPORT_SYMBOL_GPL(iomap_free); void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot) { diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h index 0adb0f91568c..97eb928b4924 100644 --- a/include/linux/io-mapping.h +++ b/include/linux/io-mapping.h @@ -49,23 +49,30 @@ static inline struct io_mapping * io_mapping_create_wc(resource_size_t base, unsigned long size) { struct io_mapping *iomap; - - if (!is_io_mapping_possible(base, size)) - return NULL; + pgprot_t prot; iomap = kmalloc(sizeof(*iomap), GFP_KERNEL); if (!iomap) - return NULL; + goto out_err; + + if (iomap_create_wc(base, size, &prot)) + goto out_free; iomap->base = base; iomap->size = size; - iomap->prot = pgprot_writecombine(__pgprot(__PAGE_KERNEL)); + iomap->prot = prot; return iomap; + +out_free: + kfree(iomap); +out_err: + return NULL; } static inline void io_mapping_free(struct io_mapping *mapping) { + iomap_free(mapping->base, mapping->size); kfree(mapping); } -- cgit v1.2.2