Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 | /*
* 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 <linux/slab.h>
#include <linux/bug.h>
#include <linux/io.h>
#include <asm/page.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
*/
struct io_mapping {
resource_size_t base;
unsigned long size;
pgprot_t prot;
void __iomem *iomem;
};
#ifdef CONFIG_HAVE_ATOMIC_IOMAP
#include <asm/iomap.h>
/*
* 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_init_wc(struct io_mapping *iomap,
resource_size_t base,
unsigned long size)
{
pgprot_t prot;
if (iomap_create_wc(base, size, &prot))
return NULL;
iomap->base = base;
iomap->size = size;
iomap->prot = prot;
return iomap;
}
static inline void
io_mapping_fini(struct io_mapping *mapping)
{
iomap_free(mapping->base, mapping->size);
}
/* Atomic map/unmap */
static inline void __iomem *
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, mapping->prot);
}
static inline void
io_mapping_unmap_atomic(void __iomem *vaddr)
{
iounmap_atomic(vaddr);
}
static inline void __iomem *
io_mapping_map_wc(struct io_mapping *mapping,
unsigned long offset,
unsigned long size)
{
resource_size_t phys_addr;
BUG_ON(offset >= mapping->size);
phys_addr = mapping->base + offset;
return ioremap_wc(phys_addr, size);
}
static inline void
io_mapping_unmap(void __iomem *vaddr)
{
iounmap(vaddr);
}
#else
#include <linux/uaccess.h>
#include <asm/pgtable.h>
/* Create the io_mapping object*/
static inline struct io_mapping *
io_mapping_init_wc(struct io_mapping *iomap,
resource_size_t base,
unsigned long size)
{
iomap->base = base;
iomap->size = size;
iomap->iomem = ioremap_wc(base, size);
#if defined(pgprot_noncached_wc) /* archs can't agree on a name ... */
iomap->prot = pgprot_noncached_wc(PAGE_KERNEL);
#elif defined(pgprot_writecombine)
iomap->prot = pgprot_writecombine(PAGE_KERNEL);
#else
iomap->prot = pgprot_noncached(PAGE_KERNEL);
#endif
return iomap;
}
static inline void
io_mapping_fini(struct io_mapping *mapping)
{
iounmap(mapping->iomem);
}
/* Non-atomic map/unmap */
static inline void __iomem *
io_mapping_map_wc(struct io_mapping *mapping,
unsigned long offset,
unsigned long size)
{
return mapping->iomem + offset;
}
static inline void
io_mapping_unmap(void __iomem *vaddr)
{
}
/* Atomic map/unmap */
static inline void __iomem *
io_mapping_map_atomic_wc(struct io_mapping *mapping,
unsigned long offset)
{
preempt_disable();
pagefault_disable();
return io_mapping_map_wc(mapping, offset, PAGE_SIZE);
}
static inline void
io_mapping_unmap_atomic(void __iomem *vaddr)
{
io_mapping_unmap(vaddr);
pagefault_enable();
preempt_enable();
}
#endif /* HAVE_ATOMIC_IOMAP */
static inline struct io_mapping *
io_mapping_create_wc(resource_size_t base,
unsigned long size)
{
struct io_mapping *iomap;
iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
if (!iomap)
return NULL;
if (!io_mapping_init_wc(iomap, base, size)) {
kfree(iomap);
return NULL;
}
return iomap;
}
static inline void
io_mapping_free(struct io_mapping *iomap)
{
io_mapping_fini(iomap);
kfree(iomap);
}
#endif /* _LINUX_IO_MAPPING_H */
|