diff options
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/iomap_32.c | 42 |
1 files changed, 40 insertions, 2 deletions
diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c index 6c2b1af1692..94596f794b1 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 * |