diff options
Diffstat (limited to 'arch/sh/mm/ioremap.c')
-rw-r--r-- | arch/sh/mm/ioremap.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/arch/sh/mm/ioremap.c b/arch/sh/mm/ioremap.c new file mode 100644 index 000000000000..c68d2d7d00a9 --- /dev/null +++ b/arch/sh/mm/ioremap.c | |||
@@ -0,0 +1,162 @@ | |||
1 | /* | ||
2 | * arch/sh/mm/ioremap.c | ||
3 | * | ||
4 | * (C) Copyright 1995 1996 Linus Torvalds | ||
5 | * (C) Copyright 2005 - 2010 Paul Mundt | ||
6 | * | ||
7 | * Re-map IO memory to kernel address space so that we can access it. | ||
8 | * This is needed for high PCI addresses that aren't mapped in the | ||
9 | * 640k-1MB IO memory area on PC's | ||
10 | * | ||
11 | * This file is subject to the terms and conditions of the GNU General | ||
12 | * Public License. See the file "COPYING" in the main directory of this | ||
13 | * archive for more details. | ||
14 | */ | ||
15 | #include <linux/vmalloc.h> | ||
16 | #include <linux/module.h> | ||
17 | #include <linux/mm.h> | ||
18 | #include <linux/pci.h> | ||
19 | #include <linux/io.h> | ||
20 | #include <asm/page.h> | ||
21 | #include <asm/pgalloc.h> | ||
22 | #include <asm/addrspace.h> | ||
23 | #include <asm/cacheflush.h> | ||
24 | #include <asm/tlbflush.h> | ||
25 | #include <asm/mmu.h> | ||
26 | |||
27 | /* | ||
28 | * Remap an arbitrary physical address space into the kernel virtual | ||
29 | * address space. Needed when the kernel wants to access high addresses | ||
30 | * directly. | ||
31 | * | ||
32 | * NOTE! We need to allow non-page-aligned mappings too: we will obviously | ||
33 | * have to convert them into an offset in a page-aligned mapping, but the | ||
34 | * caller shouldn't need to know that small detail. | ||
35 | */ | ||
36 | void __iomem * __init_refok | ||
37 | __ioremap_caller(unsigned long phys_addr, unsigned long size, | ||
38 | pgprot_t pgprot, void *caller) | ||
39 | { | ||
40 | struct vm_struct *area; | ||
41 | unsigned long offset, last_addr, addr, orig_addr; | ||
42 | |||
43 | /* Don't allow wraparound or zero size */ | ||
44 | last_addr = phys_addr + size - 1; | ||
45 | if (!size || last_addr < phys_addr) | ||
46 | return NULL; | ||
47 | |||
48 | /* | ||
49 | * Mappings have to be page-aligned | ||
50 | */ | ||
51 | offset = phys_addr & ~PAGE_MASK; | ||
52 | phys_addr &= PAGE_MASK; | ||
53 | size = PAGE_ALIGN(last_addr+1) - phys_addr; | ||
54 | |||
55 | /* | ||
56 | * If we can't yet use the regular approach, go the fixmap route. | ||
57 | */ | ||
58 | if (!mem_init_done) | ||
59 | return ioremap_fixed(phys_addr, offset, size, pgprot); | ||
60 | |||
61 | /* | ||
62 | * Ok, go for it.. | ||
63 | */ | ||
64 | area = get_vm_area_caller(size, VM_IOREMAP, caller); | ||
65 | if (!area) | ||
66 | return NULL; | ||
67 | area->phys_addr = phys_addr; | ||
68 | orig_addr = addr = (unsigned long)area->addr; | ||
69 | |||
70 | #ifdef CONFIG_PMB | ||
71 | /* | ||
72 | * First try to remap through the PMB once a valid VMA has been | ||
73 | * established. Smaller allocations (or the rest of the size | ||
74 | * remaining after a PMB mapping due to the size not being | ||
75 | * perfectly aligned on a PMB size boundary) are then mapped | ||
76 | * through the UTLB using conventional page tables. | ||
77 | * | ||
78 | * PMB entries are all pre-faulted. | ||
79 | */ | ||
80 | if (unlikely(phys_addr >= P1SEG)) { | ||
81 | unsigned long mapped; | ||
82 | |||
83 | mapped = pmb_remap(addr, phys_addr, size, pgprot); | ||
84 | if (likely(mapped)) { | ||
85 | addr += mapped; | ||
86 | phys_addr += mapped; | ||
87 | size -= mapped; | ||
88 | } | ||
89 | } | ||
90 | #endif | ||
91 | |||
92 | if (likely(size)) | ||
93 | if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) { | ||
94 | vunmap((void *)orig_addr); | ||
95 | return NULL; | ||
96 | } | ||
97 | |||
98 | return (void __iomem *)(offset + (char *)orig_addr); | ||
99 | } | ||
100 | EXPORT_SYMBOL(__ioremap_caller); | ||
101 | |||
102 | /* | ||
103 | * Simple checks for non-translatable mappings. | ||
104 | */ | ||
105 | static inline int iomapping_nontranslatable(unsigned long offset) | ||
106 | { | ||
107 | #ifdef CONFIG_29BIT | ||
108 | /* | ||
109 | * In 29-bit mode this includes the fixed P1/P2 areas, as well as | ||
110 | * parts of P3. | ||
111 | */ | ||
112 | if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX) | ||
113 | return 1; | ||
114 | #endif | ||
115 | |||
116 | return 0; | ||
117 | } | ||
118 | |||
119 | void __iounmap(void __iomem *addr) | ||
120 | { | ||
121 | unsigned long vaddr = (unsigned long __force)addr; | ||
122 | struct vm_struct *p; | ||
123 | |||
124 | /* | ||
125 | * Nothing to do if there is no translatable mapping. | ||
126 | */ | ||
127 | if (iomapping_nontranslatable(vaddr)) | ||
128 | return; | ||
129 | |||
130 | /* | ||
131 | * There's no VMA if it's from an early fixed mapping. | ||
132 | */ | ||
133 | if (iounmap_fixed(addr) == 0) | ||
134 | return; | ||
135 | |||
136 | #ifdef CONFIG_PMB | ||
137 | /* | ||
138 | * Purge any PMB entries that may have been established for this | ||
139 | * mapping, then proceed with conventional VMA teardown. | ||
140 | * | ||
141 | * XXX: Note that due to the way that remove_vm_area() does | ||
142 | * matching of the resultant VMA, we aren't able to fast-forward | ||
143 | * the address past the PMB space until the end of the VMA where | ||
144 | * the page tables reside. As such, unmap_vm_area() will be | ||
145 | * forced to linearly scan over the area until it finds the page | ||
146 | * tables where PTEs that need to be unmapped actually reside, | ||
147 | * which is far from optimal. Perhaps we need to use a separate | ||
148 | * VMA for the PMB mappings? | ||
149 | * -- PFM. | ||
150 | */ | ||
151 | pmb_unmap(vaddr); | ||
152 | #endif | ||
153 | |||
154 | p = remove_vm_area((void *)(vaddr & PAGE_MASK)); | ||
155 | if (!p) { | ||
156 | printk(KERN_ERR "%s: bad address %p\n", __func__, addr); | ||
157 | return; | ||
158 | } | ||
159 | |||
160 | kfree(p); | ||
161 | } | ||
162 | EXPORT_SYMBOL(__iounmap); | ||