Keith Packard | 9663f2e | 2008-10-30 19:38:18 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright © 2008 Keith Packard <keithp@keithp.com> |
| 3 | * |
| 4 | * This file is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of version 2 of the GNU General Public License |
| 6 | * as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License |
| 14 | * along with this program; if not, write to the Free Software Foundation, |
| 15 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. |
| 16 | */ |
| 17 | |
| 18 | #ifndef _LINUX_IO_MAPPING_H |
| 19 | #define _LINUX_IO_MAPPING_H |
| 20 | |
| 21 | #include <linux/types.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame^] | 22 | #include <linux/slab.h> |
Keith Packard | 9663f2e | 2008-10-30 19:38:18 -0700 | [diff] [blame] | 23 | #include <asm/io.h> |
| 24 | #include <asm/page.h> |
| 25 | #include <asm/iomap.h> |
| 26 | |
| 27 | /* |
| 28 | * The io_mapping mechanism provides an abstraction for mapping |
| 29 | * individual pages from an io device to the CPU in an efficient fashion. |
| 30 | * |
| 31 | * See Documentation/io_mapping.txt |
| 32 | */ |
| 33 | |
Keith Packard | e5beae1 | 2008-11-03 18:21:45 +0100 | [diff] [blame] | 34 | #ifdef CONFIG_HAVE_ATOMIC_IOMAP |
Keith Packard | 9663f2e | 2008-10-30 19:38:18 -0700 | [diff] [blame] | 35 | |
Venkatesh Pallipadi | 4ab0d47 | 2009-02-24 17:35:12 -0800 | [diff] [blame] | 36 | struct io_mapping { |
| 37 | resource_size_t base; |
| 38 | unsigned long size; |
| 39 | pgprot_t prot; |
| 40 | }; |
| 41 | |
Keith Packard | e5beae1 | 2008-11-03 18:21:45 +0100 | [diff] [blame] | 42 | /* |
| 43 | * For small address space machines, mapping large objects |
| 44 | * into the kernel virtual space isn't practical. Where |
| 45 | * available, use fixmap support to dynamically map pages |
| 46 | * of the object at run time. |
| 47 | */ |
Keith Packard | 9663f2e | 2008-10-30 19:38:18 -0700 | [diff] [blame] | 48 | |
Keith Packard | 9663f2e | 2008-10-30 19:38:18 -0700 | [diff] [blame] | 49 | static inline struct io_mapping * |
Venkatesh Pallipadi | 4ab0d47 | 2009-02-24 17:35:12 -0800 | [diff] [blame] | 50 | io_mapping_create_wc(resource_size_t base, unsigned long size) |
Keith Packard | 9663f2e | 2008-10-30 19:38:18 -0700 | [diff] [blame] | 51 | { |
Venkatesh Pallipadi | 4ab0d47 | 2009-02-24 17:35:12 -0800 | [diff] [blame] | 52 | struct io_mapping *iomap; |
Venkatesh Pallipadi | 9e36fda0 | 2009-07-10 09:57:35 -0700 | [diff] [blame] | 53 | pgprot_t prot; |
Venkatesh Pallipadi | 4ab0d47 | 2009-02-24 17:35:12 -0800 | [diff] [blame] | 54 | |
| 55 | iomap = kmalloc(sizeof(*iomap), GFP_KERNEL); |
| 56 | if (!iomap) |
Venkatesh Pallipadi | 9e36fda0 | 2009-07-10 09:57:35 -0700 | [diff] [blame] | 57 | goto out_err; |
| 58 | |
| 59 | if (iomap_create_wc(base, size, &prot)) |
| 60 | goto out_free; |
Venkatesh Pallipadi | 4ab0d47 | 2009-02-24 17:35:12 -0800 | [diff] [blame] | 61 | |
| 62 | iomap->base = base; |
| 63 | iomap->size = size; |
Venkatesh Pallipadi | 9e36fda0 | 2009-07-10 09:57:35 -0700 | [diff] [blame] | 64 | iomap->prot = prot; |
Venkatesh Pallipadi | 4ab0d47 | 2009-02-24 17:35:12 -0800 | [diff] [blame] | 65 | return iomap; |
Venkatesh Pallipadi | 9e36fda0 | 2009-07-10 09:57:35 -0700 | [diff] [blame] | 66 | |
| 67 | out_free: |
| 68 | kfree(iomap); |
| 69 | out_err: |
| 70 | return NULL; |
Keith Packard | 9663f2e | 2008-10-30 19:38:18 -0700 | [diff] [blame] | 71 | } |
| 72 | |
| 73 | static inline void |
| 74 | io_mapping_free(struct io_mapping *mapping) |
| 75 | { |
Venkatesh Pallipadi | 9e36fda0 | 2009-07-10 09:57:35 -0700 | [diff] [blame] | 76 | iomap_free(mapping->base, mapping->size); |
Venkatesh Pallipadi | 4ab0d47 | 2009-02-24 17:35:12 -0800 | [diff] [blame] | 77 | kfree(mapping); |
Keith Packard | 9663f2e | 2008-10-30 19:38:18 -0700 | [diff] [blame] | 78 | } |
| 79 | |
| 80 | /* Atomic map/unmap */ |
| 81 | static inline void * |
| 82 | io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) |
| 83 | { |
Venkatesh Pallipadi | 4ab0d47 | 2009-02-24 17:35:12 -0800 | [diff] [blame] | 84 | resource_size_t phys_addr; |
| 85 | unsigned long pfn; |
| 86 | |
| 87 | BUG_ON(offset >= mapping->size); |
| 88 | phys_addr = mapping->base + offset; |
| 89 | pfn = (unsigned long) (phys_addr >> PAGE_SHIFT); |
| 90 | return iomap_atomic_prot_pfn(pfn, KM_USER0, mapping->prot); |
Keith Packard | 9663f2e | 2008-10-30 19:38:18 -0700 | [diff] [blame] | 91 | } |
| 92 | |
| 93 | static inline void |
| 94 | io_mapping_unmap_atomic(void *vaddr) |
| 95 | { |
| 96 | iounmap_atomic(vaddr, KM_USER0); |
| 97 | } |
| 98 | |
| 99 | static inline void * |
| 100 | io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) |
| 101 | { |
Pallipadi, Venkatesh | 5ce04e3 | 2009-03-01 08:53:27 -0800 | [diff] [blame] | 102 | resource_size_t phys_addr; |
| 103 | |
Venkatesh Pallipadi | 4ab0d47 | 2009-02-24 17:35:12 -0800 | [diff] [blame] | 104 | BUG_ON(offset >= mapping->size); |
Pallipadi, Venkatesh | 5ce04e3 | 2009-03-01 08:53:27 -0800 | [diff] [blame] | 105 | phys_addr = mapping->base + offset; |
| 106 | |
Venkatesh Pallipadi | 4ab0d47 | 2009-02-24 17:35:12 -0800 | [diff] [blame] | 107 | return ioremap_wc(phys_addr, PAGE_SIZE); |
Keith Packard | 9663f2e | 2008-10-30 19:38:18 -0700 | [diff] [blame] | 108 | } |
| 109 | |
| 110 | static inline void |
| 111 | io_mapping_unmap(void *vaddr) |
| 112 | { |
| 113 | iounmap(vaddr); |
| 114 | } |
Keith Packard | e5beae1 | 2008-11-03 18:21:45 +0100 | [diff] [blame] | 115 | |
| 116 | #else |
| 117 | |
Venkatesh Pallipadi | 4ab0d47 | 2009-02-24 17:35:12 -0800 | [diff] [blame] | 118 | /* this struct isn't actually defined anywhere */ |
| 119 | struct io_mapping; |
| 120 | |
Keith Packard | e5beae1 | 2008-11-03 18:21:45 +0100 | [diff] [blame] | 121 | /* Create the io_mapping object*/ |
| 122 | static inline struct io_mapping * |
Venkatesh Pallipadi | 4ab0d47 | 2009-02-24 17:35:12 -0800 | [diff] [blame] | 123 | io_mapping_create_wc(resource_size_t base, unsigned long size) |
Keith Packard | e5beae1 | 2008-11-03 18:21:45 +0100 | [diff] [blame] | 124 | { |
| 125 | return (struct io_mapping *) ioremap_wc(base, size); |
| 126 | } |
| 127 | |
| 128 | static inline void |
| 129 | io_mapping_free(struct io_mapping *mapping) |
| 130 | { |
| 131 | iounmap(mapping); |
| 132 | } |
| 133 | |
| 134 | /* Atomic map/unmap */ |
| 135 | static inline void * |
| 136 | io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) |
| 137 | { |
| 138 | return ((char *) mapping) + offset; |
| 139 | } |
| 140 | |
| 141 | static inline void |
| 142 | io_mapping_unmap_atomic(void *vaddr) |
| 143 | { |
| 144 | } |
| 145 | |
| 146 | /* Non-atomic map/unmap */ |
| 147 | static inline void * |
| 148 | io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) |
| 149 | { |
| 150 | return ((char *) mapping) + offset; |
| 151 | } |
| 152 | |
| 153 | static inline void |
| 154 | io_mapping_unmap(void *vaddr) |
| 155 | { |
| 156 | } |
| 157 | |
| 158 | #endif /* HAVE_ATOMIC_IOMAP */ |
Keith Packard | 9663f2e | 2008-10-30 19:38:18 -0700 | [diff] [blame] | 159 | |
| 160 | #endif /* _LINUX_IO_MAPPING_H */ |