2 * Re-map IO memory to kernel address space so that we can access it.
4 * These functions should only be used when it is necessary to map a
5 * physical address space into the kernel address space before ioremap()
6 * can be used, e.g. early in boot before paging_init().
8 * Copyright (C) 2009 Matt Fleming
11 #include <linux/vmalloc.h>
12 #include <linux/ioport.h>
13 #include <linux/module.h>
16 #include <linux/bootmem.h>
17 #include <linux/proc_fs.h>
18 #include <linux/slab.h>
19 #include <asm/fixmap.h>
21 #include <asm/pgalloc.h>
22 #include <asm/addrspace.h>
23 #include <asm/cacheflush.h>
24 #include <asm/tlbflush.h>
26 #include <asm/mmu_context.h>
31 unsigned long fixmap_addr;
34 static struct ioremap_map ioremap_maps[FIX_N_IOREMAPS];
36 void __init ioremap_fixed_init(void)
38 struct ioremap_map *map;
41 for (i = 0; i < FIX_N_IOREMAPS; i++) {
42 map = &ioremap_maps[i];
43 map->fixmap_addr = __fix_to_virt(FIX_IOREMAP_BEGIN + i);
48 ioremap_fixed(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
50 enum fixed_addresses idx0, idx;
51 resource_size_t last_addr;
52 struct ioremap_map *map;
58 for (i = 0; i < FIX_N_IOREMAPS; i++) {
59 map = &ioremap_maps[i];
70 /* Don't allow wraparound or zero size */
71 last_addr = phys_addr + size - 1;
72 if (!size || last_addr < phys_addr)
76 * Fixmap mappings have to be page-aligned
78 offset = phys_addr & ~PAGE_MASK;
79 phys_addr &= PAGE_MASK;
80 size = PAGE_ALIGN(last_addr + 1) - phys_addr;
83 * Mappings have to fit in the FIX_IOREMAP area.
85 nrpages = size >> PAGE_SHIFT;
86 if (nrpages > FIX_N_IOREMAPS)
92 idx0 = FIX_IOREMAP_BEGIN + slot;
95 pgprot_val(prot) |= _PAGE_WIRED;
96 __set_fixmap(idx, phys_addr, prot);
97 phys_addr += PAGE_SIZE;
102 map->addr = (void __iomem *)(offset + map->fixmap_addr);
106 void __init iounmap_fixed(void __iomem *addr)
108 enum fixed_addresses idx;
109 unsigned long virt_addr;
110 struct ioremap_map *map;
111 unsigned long offset;
112 unsigned int nrpages;
117 for (i = 0; i < FIX_N_IOREMAPS; i++) {
118 map = &ioremap_maps[i];
119 if (map->addr == addr) {
128 virt_addr = (unsigned long)addr;
130 offset = virt_addr & ~PAGE_MASK;
131 nrpages = PAGE_ALIGN(offset + map->size - 1) >> PAGE_SHIFT;
133 pgprot_val(prot) = _PAGE_WIRED;
135 idx = FIX_IOREMAP_BEGIN + slot + nrpages;
136 while (nrpages > 0) {
137 __clear_fixmap(idx, prot);