diff options
Diffstat (limited to 'libdde-linux26/libdde_linux26/contrib/include/linux/io-mapping.h')
-rw-r--r-- | libdde-linux26/libdde_linux26/contrib/include/linux/io-mapping.h | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/libdde-linux26/libdde_linux26/contrib/include/linux/io-mapping.h b/libdde-linux26/libdde_linux26/contrib/include/linux/io-mapping.h new file mode 100644 index 00000000..0adb0f91 --- /dev/null +++ b/libdde-linux26/libdde_linux26/contrib/include/linux/io-mapping.h @@ -0,0 +1,152 @@ +/* + * Copyright © 2008 Keith Packard <keithp@keithp.com> + * + * This file is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#ifndef _LINUX_IO_MAPPING_H +#define _LINUX_IO_MAPPING_H + +#include <linux/types.h> +#include <asm/io.h> +#include <asm/page.h> +#include <asm/iomap.h> + +/* + * The io_mapping mechanism provides an abstraction for mapping + * individual pages from an io device to the CPU in an efficient fashion. + * + * See Documentation/io_mapping.txt + */ + +#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 + * available, use fixmap support to dynamically map pages + * of the object at run time. + */ + +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; + + 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) +{ + 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 +io_mapping_unmap_atomic(void *vaddr) +{ + iounmap_atomic(vaddr, KM_USER0); +} + +static inline void * +io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) +{ + resource_size_t phys_addr; + + BUG_ON(offset >= mapping->size); + phys_addr = mapping->base + offset; + + return ioremap_wc(phys_addr, PAGE_SIZE); +} + +static inline void +io_mapping_unmap(void *vaddr) +{ + iounmap(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(resource_size_t base, unsigned long size) +{ + return (struct io_mapping *) ioremap_wc(base, size); +} + +static inline void +io_mapping_free(struct io_mapping *mapping) +{ + iounmap(mapping); +} + +/* Atomic map/unmap */ +static inline void * +io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) +{ + return ((char *) mapping) + offset; +} + +static inline void +io_mapping_unmap_atomic(void *vaddr) +{ +} + +/* Non-atomic map/unmap */ +static inline void * +io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) +{ + return ((char *) mapping) + offset; +} + +static inline void +io_mapping_unmap(void *vaddr) +{ +} + +#endif /* HAVE_ATOMIC_IOMAP */ + +#endif /* _LINUX_IO_MAPPING_H */ |