| 1 | |
| 2 | * Copyright © 2008 Keith Packard <[email protected]>
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| 3 | *
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| 4 | * This file is free software; you can redistribute it and/or modify
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| 5 | * it under the terms of version 2 of the GNU General Public License
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| 6 | * as published by the Free Software Foundation.
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| 7 | *
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| 8 | * This program is distributed in the hope that it will be useful,
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| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 11 | * GNU General Public License for more details.
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| 12 | *
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| 13 | * You should have received a copy of the GNU General Public License
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| 14 | * along with this program; if not, write to the Free Software Foundation,
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| 15 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
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| 16 |
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| 17 |
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| 18 | #ifndef _LINUX_IO_MAPPING_H
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| 19 | #define _LINUX_IO_MAPPING_H
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| 20 |
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| 21 | #include <linux/types.h>
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| 22 | #include <linux/slab.h>
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| 23 | #include <linux/bug.h>
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| 24 | #include <asm/io.h>
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| 25 | #include <asm/page.h>
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| 26 |
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| 27 | |
| 28 | * The io_mapping mechanism provides an abstraction for mapping
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| 29 | * individual pages from an io device to the CPU in an efficient fashion.
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| 30 | *
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| 31 | * See Documentation/io-mapping.txt
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| 32 |
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| 33 |
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| 34 | #ifdef CONFIG_HAVE_ATOMIC_IOMAP
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| 35 |
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| 36 | #include <asm/iomap.h>
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| 37 |
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| 38 | struct io_mapping {
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| 39 | resource_size_t base;
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| 40 | unsigned long size;
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| 41 | pgprot_t prot;
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| 42 | };
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| 43 |
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| 44 | |
| 45 | * For small address space machines, mapping large objects
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| 46 | * into the kernel virtual space isn't practical. Where
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| 47 | * available, use fixmap support to dynamically map pages
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| 48 | * of the object at run time.
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| 49 |
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| 50 |
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| 51 | static inline struct io_mapping *
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| 52 | io_mapping_create_wc(resource_size_t base, unsigned long size)
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| 53 | {
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| 54 | struct io_mapping *iomap;
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| 55 | pgprot_t prot;
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| 56 |
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| 57 | iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
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| 58 | if (!iomap)
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| 59 | goto out_err;
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| 60 |
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| 61 | if (iomap_create_wc(base, size, &prot))
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| 62 | goto out_free;
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| 63 |
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| 64 | iomap->base = base;
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| 65 | iomap->size = size;
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| 66 | iomap->prot = prot;
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| 67 | return iomap;
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| 68 |
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| 69 | out_free:
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| 70 | kfree(iomap);
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| 71 | out_err:
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| 72 | return NULL;
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| 73 | }
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| 74 |
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| 75 | static inline void
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| 76 | io_mapping_free(struct io_mapping *mapping)
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| 77 | {
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| 78 | iomap_free(mapping->base, mapping->size);
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| 79 | kfree(mapping);
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| 80 | }
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| 81 |
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| 82 |
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| 83 | static inline void __iomem *
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| 84 | io_mapping_map_atomic_wc(struct io_mapping *mapping,
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| 85 | unsigned long offset)
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| 86 | {
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| 87 | resource_size_t phys_addr;
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| 88 | unsigned long pfn;
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| 89 |
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| 90 | BUG_ON(offset >= mapping->size);
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| 91 | phys_addr = mapping->base + offset;
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| 92 | pfn = (unsigned long) (phys_addr >> PAGE_SHIFT);
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| 93 | return iomap_atomic_prot_pfn(pfn, mapping->prot);
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| 94 | }
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| 95 |
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| 96 | static inline void
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| 97 | io_mapping_unmap_atomic(void __iomem *vaddr)
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| 98 | {
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| 99 | iounmap_atomic(vaddr);
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| 100 | }
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| 101 |
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| 102 | static inline void __iomem *
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| 103 | io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
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| 104 | {
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| 105 | resource_size_t phys_addr;
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| 106 |
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| 107 | BUG_ON(offset >= mapping->size);
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| 108 | phys_addr = mapping->base + offset;
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| 109 |
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| 110 | return ioremap_wc(phys_addr, PAGE_SIZE);
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| 111 | }
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| 112 |
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| 113 | static inline void
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| 114 | io_mapping_unmap(void __iomem *vaddr)
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| 115 | {
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| 116 | iounmap(vaddr);
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| 117 | }
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| 118 |
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| 119 | #else
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| 120 |
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| 121 | #include <linux/uaccess.h>
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| 122 |
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| 123 |
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| 124 | struct io_mapping;
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| 125 |
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| 126 |
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| 127 | static inline struct io_mapping *
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| 128 | io_mapping_create_wc(resource_size_t base, unsigned long size)
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| 129 | {
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| 130 | return (struct io_mapping __force *) ioremap_wc(base, size);
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| 131 | }
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| 132 |
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| 133 | static inline void
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| 134 | io_mapping_free(struct io_mapping *mapping)
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| 135 | {
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| 136 | iounmap((void __force __iomem *) mapping);
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| 137 | }
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| 138 |
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| 139 |
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| 140 | static inline void __iomem *
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| 141 | io_mapping_map_atomic_wc(struct io_mapping *mapping,
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| 142 | unsigned long offset)
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| 143 | {
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| 144 | pagefault_disable();
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| 145 | return ((char __force __iomem *) mapping) + offset;
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| 146 | }
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| 147 |
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| 148 | static inline void
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| 149 | io_mapping_unmap_atomic(void __iomem *vaddr)
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| 150 | {
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| 151 | pagefault_enable();
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| 152 | }
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| 153 |
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| 154 |
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| 155 | static inline void __iomem *
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| 156 | io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
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| 157 | {
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| 158 | return ((char __force __iomem *) mapping) + offset;
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| 159 | }
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| 160 |
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| 161 | static inline void
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| 162 | io_mapping_unmap(void __iomem *vaddr)
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| 163 | {
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| 164 | }
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| 165 |
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| 166 | #endif
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| 167 |
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| 168 | #endif
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