diff options
| -rw-r--r-- | arch/x86/include/asm/iomap.h | 5 | ||||
| -rw-r--r-- | arch/x86/mm/iomap_32.c | 42 | ||||
| -rw-r--r-- | include/linux/io-mapping.h | 6 |
3 files changed, 48 insertions, 5 deletions
diff --git a/arch/x86/include/asm/iomap.h b/arch/x86/include/asm/iomap.h index 86af26091d6c..bd46495ff7de 100644 --- a/arch/x86/include/asm/iomap.h +++ b/arch/x86/include/asm/iomap.h @@ -24,7 +24,10 @@ #include <asm/tlbflush.h> int -is_io_mapping_possible(resource_size_t base, unsigned long size); +reserve_io_memtype_wc(u64 base, unsigned long size, pgprot_t *prot); + +void +free_io_memtype(u64 base, unsigned long size); void * iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot); diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c index 6c2b1af16926..94596f794b1b 100644 --- a/arch/x86/mm/iomap_32.c +++ b/arch/x86/mm/iomap_32.c @@ -21,13 +21,13 @@ #include <linux/module.h> #ifdef CONFIG_X86_PAE -int +static int is_io_mapping_possible(resource_size_t base, unsigned long size) { return 1; } #else -int +static int is_io_mapping_possible(resource_size_t base, unsigned long size) { /* There is no way to map greater than 1 << 32 address without PAE */ @@ -38,6 +38,44 @@ is_io_mapping_possible(resource_size_t base, unsigned long size) } #endif +int +reserve_io_memtype_wc(u64 base, unsigned long size, pgprot_t *prot) +{ + unsigned long ret_flag; + + if (!is_io_mapping_possible(base, size)) + goto out_err; + + if (!pat_enabled) { + *prot = pgprot_noncached(PAGE_KERNEL); + return 0; + } + + if (reserve_memtype(base, base + size, _PAGE_CACHE_WC, &ret_flag)) + goto out_err; + + if (ret_flag == _PAGE_CACHE_WB) + goto out_free; + + if (kernel_map_sync_memtype(base, size, ret_flag)) + goto out_free; + + *prot = __pgprot(__PAGE_KERNEL | ret_flag); + return 0; + +out_free: + free_memtype(base, base + size); +out_err: + return -EINVAL; +} + +void +free_io_memtype(u64 base, unsigned long size) +{ + if (pat_enabled) + free_memtype(base, base + size); +} + /* Map 'pfn' using fixed map 'type' and protections 'prot' */ void * diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h index cbc2f0cd631b..f1ed66c43787 100644 --- a/include/linux/io-mapping.h +++ b/include/linux/io-mapping.h @@ -49,8 +49,9 @@ static inline struct io_mapping * io_mapping_create_wc(resource_size_t base, unsigned long size) { struct io_mapping *iomap; + pgprot_t prot; - if (!is_io_mapping_possible(base, size)) + if (!reserve_io_memtype_wc(base, size, &prot)) return NULL; iomap = kmalloc(sizeof(*iomap), GFP_KERNEL); @@ -59,13 +60,14 @@ io_mapping_create_wc(resource_size_t base, unsigned long size) iomap->base = base; iomap->size = size; - iomap->prot = pgprot_writecombine(__pgprot(__PAGE_KERNEL)); + iomap->prot = prot; return iomap; } static inline void io_mapping_free(struct io_mapping *mapping) { + free_io_memtype(mapping->base, mapping->size); kfree(mapping); } |