diff options
| -rw-r--r-- | arch/x86/include/asm/iomap.h | 3 | ||||
| -rw-r--r-- | arch/x86/mm/iomap_32.c | 18 | ||||
| -rw-r--r-- | include/linux/io-mapping.h | 46 |
3 files changed, 56 insertions, 11 deletions
diff --git a/arch/x86/include/asm/iomap.h b/arch/x86/include/asm/iomap.h index c1f06289b14b..86af26091d6c 100644 --- a/arch/x86/include/asm/iomap.h +++ b/arch/x86/include/asm/iomap.h @@ -23,6 +23,9 @@ #include <asm/pgtable.h> #include <asm/tlbflush.h> +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); diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c index ca53224fc56c..6c2b1af16926 100644 --- a/arch/x86/mm/iomap_32.c +++ b/arch/x86/mm/iomap_32.c @@ -20,6 +20,24 @@ #include <asm/pat.h> #include <linux/module.h> +#ifdef CONFIG_X86_PAE +int +is_io_mapping_possible(resource_size_t base, unsigned long size) +{ + return 1; +} +#else +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 */ + if (base + size > 0x100000000ULL) + return 0; + + return 1; +} +#endif + /* 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 82df31726a54..cbc2f0cd631b 100644 --- a/include/linux/io-mapping.h +++ b/include/linux/io-mapping.h @@ -30,11 +30,14 @@ * See Documentation/io_mapping.txt */ -/* this struct isn't actually defined anywhere */ -struct io_mapping; - #ifdef CONFIG_HAVE_ATOMIC_IOMAP +struct io_mapping { + resource_size_t base; + unsigned long size; + pgprot_t prot; +}; + /* * For small address space machines, mapping large objects * into the kernel virtual space isn't practical. Where @@ -43,23 +46,40 @@ struct io_mapping; */ static inline struct io_mapping * -io_mapping_create_wc(unsigned long base, unsigned long size) +io_mapping_create_wc(resource_size_t base, unsigned long size) { - return (struct io_mapping *) base; + struct io_mapping *iomap; + + if (!is_io_mapping_possible(base, size)) + return NULL; + + iomap = kmalloc(sizeof(*iomap), GFP_KERNEL); + if (!iomap) + return NULL; + + iomap->base = base; + iomap->size = size; + iomap->prot = pgprot_writecombine(__pgprot(__PAGE_KERNEL)); + return iomap; } static inline void io_mapping_free(struct io_mapping *mapping) { + kfree(mapping); } /* Atomic map/unmap */ static inline void * io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) { - offset += (unsigned long) mapping; - return iomap_atomic_prot_pfn(offset >> PAGE_SHIFT, KM_USER0, - __pgprot(__PAGE_KERNEL_WC)); + resource_size_t phys_addr; + unsigned long pfn; + + BUG_ON(offset >= mapping->size); + phys_addr = mapping->base + offset; + pfn = (unsigned long) (phys_addr >> PAGE_SHIFT); + return iomap_atomic_prot_pfn(pfn, KM_USER0, mapping->prot); } static inline void @@ -71,8 +91,9 @@ io_mapping_unmap_atomic(void *vaddr) static inline void * io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) { - offset += (unsigned long) mapping; - return ioremap_wc(offset, PAGE_SIZE); + BUG_ON(offset >= mapping->size); + resource_size_t phys_addr = mapping->base + offset; + return ioremap_wc(phys_addr, PAGE_SIZE); } static inline void @@ -83,9 +104,12 @@ io_mapping_unmap(void *vaddr) #else +/* this struct isn't actually defined anywhere */ +struct io_mapping; + /* Create the io_mapping object*/ static inline struct io_mapping * -io_mapping_create_wc(unsigned long base, unsigned long size) +io_mapping_create_wc(resource_size_t base, unsigned long size) { return (struct io_mapping *) ioremap_wc(base, size); } |