diff options
| -rw-r--r-- | arch/x86/include/asm/iomap.h | 5 | ||||
| -rw-r--r-- | arch/x86/include/asm/pat.h | 3 | ||||
| -rw-r--r-- | arch/x86/mm/iomap_32.c | 44 | ||||
| -rw-r--r-- | arch/x86/mm/pat.c | 46 | ||||
| -rw-r--r-- | include/linux/io-mapping.h | 6 |
5 files changed, 82 insertions, 22 deletions
diff --git a/arch/x86/include/asm/iomap.h b/arch/x86/include/asm/iomap.h index 86af26091d6..bd46495ff7d 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/include/asm/pat.h b/arch/x86/include/asm/pat.h index 9709fdff661..b0e70056838 100644 --- a/arch/x86/include/asm/pat.h +++ b/arch/x86/include/asm/pat.h @@ -15,4 +15,7 @@ extern int reserve_memtype(u64 start, u64 end, unsigned long req_type, unsigned long *ret_type); extern int free_memtype(u64 start, u64 end); +extern int kernel_map_sync_memtype(u64 base, unsigned long size, + unsigned long flag); + #endif /* _ASM_X86_PAT_H */ diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c index 6c2b1af1692..d5e28424622 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 +38,46 @@ 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; +} +EXPORT_SYMBOL_GPL(reserve_io_memtype_wc); + +void +free_io_memtype(u64 base, unsigned long size) +{ + if (pat_enabled) + free_memtype(base, base + size); +} +EXPORT_SYMBOL_GPL(free_io_memtype); + /* Map 'pfn' using fixed map 'type' and protections 'prot' */ void * diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 05f9aef6818..fdfedb65d45 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -634,6 +634,33 @@ void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot) } /* + * Change the memory type for the physial address range in kernel identity + * mapping space if that range is a part of identity map. + */ +int kernel_map_sync_memtype(u64 base, unsigned long size, unsigned long flags) +{ + unsigned long id_sz; + + if (!pat_enabled || base >= __pa(high_memory)) + return 0; + + id_sz = (__pa(high_memory) < base + size) ? + __pa(high_memory) - base : + size; + + if (ioremap_change_attr((unsigned long)__va(base), id_sz, flags) < 0) { + printk(KERN_INFO + "%s:%d ioremap_change_attr failed %s " + "for %Lx-%Lx\n", + current->comm, current->pid, + cattr_name(flags), + base, (unsigned long long)(base + size)); + return -EINVAL; + } + return 0; +} + +/* * Internal interface to reserve a range of physical memory with prot. * Reserved non RAM regions only and after successful reserve_memtype, * this func also keeps identity mapping (if any) in sync with this new prot. @@ -642,7 +669,7 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, int strict_prot) { int is_ram = 0; - int id_sz, ret; + int ret; unsigned long flags; unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK); @@ -679,23 +706,8 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, flags); } - /* Need to keep identity mapping in sync */ - if (paddr >= __pa(high_memory)) - return 0; - - id_sz = (__pa(high_memory) < paddr + size) ? - __pa(high_memory) - paddr : - size; - - if (ioremap_change_attr((unsigned long)__va(paddr), id_sz, flags) < 0) { + if (kernel_map_sync_memtype(paddr, size, flags) < 0) { free_memtype(paddr, paddr + size); - printk(KERN_ERR - "%s:%d reserve_pfn_range ioremap_change_attr failed %s " - "for %Lx-%Lx\n", - current->comm, current->pid, - cattr_name(flags), - (unsigned long long)paddr, - (unsigned long long)(paddr + size)); return -EINVAL; } return 0; diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h index cbc2f0cd631..f1ed66c4378 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); } |