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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * arch/x86_64/mm/ioremap.c | |
3 | * | |
4 | * Re-map IO memory to kernel address space so that we can access it. | |
5 | * This is needed for high PCI addresses that aren't mapped in the | |
6 | * 640k-1MB IO memory area on PC's | |
7 | * | |
8 | * (C) Copyright 1995 1996 Linus Torvalds | |
9 | */ | |
10 | ||
11 | #include <linux/vmalloc.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/slab.h> | |
2ee60e17 | 14 | #include <linux/module.h> |
16c564bb | 15 | #include <linux/io.h> |
e3ebadd9 | 16 | |
1da177e4 LT |
17 | #include <asm/pgalloc.h> |
18 | #include <asm/fixmap.h> | |
1da177e4 | 19 | #include <asm/tlbflush.h> |
16c564bb | 20 | #include <asm/cacheflush.h> |
1da177e4 | 21 | #include <asm/proto.h> |
306c142f | 22 | #include <asm/e820.h> |
1da177e4 | 23 | |
e3ebadd9 LT |
24 | unsigned long __phys_addr(unsigned long x) |
25 | { | |
26 | if (x >= __START_KERNEL_map) | |
27 | return x - __START_KERNEL_map + phys_base; | |
28 | return x - PAGE_OFFSET; | |
29 | } | |
30 | EXPORT_SYMBOL(__phys_addr); | |
31 | ||
1da177e4 LT |
32 | /* |
33 | * Fix up the linear direct mapping of the kernel to avoid cache attribute | |
34 | * conflicts. | |
35 | */ | |
36 | static int | |
37 | ioremap_change_attr(unsigned long phys_addr, unsigned long size, | |
38 | unsigned long flags) | |
39 | { | |
40 | int err = 0; | |
7856dfeb | 41 | if (phys_addr + size - 1 < (end_pfn_map << PAGE_SHIFT)) { |
1da177e4 LT |
42 | unsigned long npages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
43 | unsigned long vaddr = (unsigned long) __va(phys_addr); | |
1c17f4d6 | 44 | int level; |
1da177e4 | 45 | |
1c17f4d6 HY |
46 | /* |
47 | * If there is no identity map for this address, | |
48 | * change_page_attr_addr is unnecessary | |
49 | */ | |
50 | if (!lookup_address(vaddr, &level)) | |
51 | return err; | |
1da177e4 LT |
52 | /* |
53 | * Must use a address here and not struct page because the phys addr | |
54 | * can be a in hole between nodes and not have an memmap entry. | |
55 | */ | |
1aaf74e9 | 56 | err = change_page_attr_addr(vaddr,npages,MAKE_GLOBAL(__PAGE_KERNEL|flags)); |
1da177e4 LT |
57 | if (!err) |
58 | global_flush_tlb(); | |
59 | } | |
60 | return err; | |
61 | } | |
62 | ||
63 | /* | |
64 | * Generic mapping function | |
65 | */ | |
66 | ||
67 | /* | |
68 | * Remap an arbitrary physical address space into the kernel virtual | |
69 | * address space. Needed when the kernel wants to access high addresses | |
70 | * directly. | |
71 | * | |
72 | * NOTE! We need to allow non-page-aligned mappings too: we will obviously | |
73 | * have to convert them into an offset in a page-aligned mapping, but the | |
74 | * caller shouldn't need to know that small detail. | |
75 | */ | |
76 | void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) | |
77 | { | |
78 | void * addr; | |
79 | struct vm_struct * area; | |
80 | unsigned long offset, last_addr; | |
16c564bb | 81 | pgprot_t pgprot; |
1da177e4 LT |
82 | |
83 | /* Don't allow wraparound or zero size */ | |
84 | last_addr = phys_addr + size - 1; | |
85 | if (!size || last_addr < phys_addr) | |
86 | return NULL; | |
87 | ||
88 | /* | |
89 | * Don't remap the low PCI/ISA area, it's always mapped.. | |
90 | */ | |
91 | if (phys_addr >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS) | |
92 | return (__force void __iomem *)phys_to_virt(phys_addr); | |
93 | ||
1aaf74e9 | 94 | pgprot = MAKE_GLOBAL(__PAGE_KERNEL | flags); |
1da177e4 LT |
95 | /* |
96 | * Mappings have to be page-aligned | |
97 | */ | |
98 | offset = phys_addr & ~PAGE_MASK; | |
99 | phys_addr &= PAGE_MASK; | |
100 | size = PAGE_ALIGN(last_addr+1) - phys_addr; | |
101 | ||
102 | /* | |
103 | * Ok, go for it.. | |
104 | */ | |
105 | area = get_vm_area(size, VM_IOREMAP | (flags << 20)); | |
106 | if (!area) | |
107 | return NULL; | |
108 | area->phys_addr = phys_addr; | |
109 | addr = area->addr; | |
16c564bb HS |
110 | if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size, |
111 | phys_addr, pgprot)) { | |
1da177e4 LT |
112 | remove_vm_area((void *)(PAGE_MASK & (unsigned long) addr)); |
113 | return NULL; | |
114 | } | |
7856dfeb | 115 | if (flags && ioremap_change_attr(phys_addr, size, flags) < 0) { |
1da177e4 LT |
116 | area->flags &= 0xffffff; |
117 | vunmap(addr); | |
118 | return NULL; | |
119 | } | |
120 | return (__force void __iomem *) (offset + (char *)addr); | |
121 | } | |
2ee60e17 | 122 | EXPORT_SYMBOL(__ioremap); |
1da177e4 LT |
123 | |
124 | /** | |
125 | * ioremap_nocache - map bus memory into CPU space | |
126 | * @offset: bus address of the memory | |
127 | * @size: size of the resource to map | |
128 | * | |
129 | * ioremap_nocache performs a platform specific sequence of operations to | |
130 | * make bus memory CPU accessible via the readb/readw/readl/writeb/ | |
131 | * writew/writel functions and the other mmio helpers. The returned | |
132 | * address is not guaranteed to be usable directly as a virtual | |
133 | * address. | |
134 | * | |
135 | * This version of ioremap ensures that the memory is marked uncachable | |
136 | * on the CPU as well as honouring existing caching rules from things like | |
137 | * the PCI bus. Note that there are other caches and buffers on many | |
138 | * busses. In particular driver authors should read up on PCI writes | |
139 | * | |
140 | * It's useful if some control registers are in such an area and | |
141 | * write combining or read caching is not desirable: | |
142 | * | |
143 | * Must be freed with iounmap. | |
144 | */ | |
145 | ||
146 | void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size) | |
147 | { | |
4138cc34 | 148 | return __ioremap(phys_addr, size, _PAGE_PCD | _PAGE_PWT); |
1da177e4 | 149 | } |
2ee60e17 | 150 | EXPORT_SYMBOL(ioremap_nocache); |
1da177e4 | 151 | |
bf5421c3 AK |
152 | /** |
153 | * iounmap - Free a IO remapping | |
154 | * @addr: virtual address from ioremap_* | |
155 | * | |
156 | * Caller must ensure there is only one unmapping for the same pointer. | |
157 | */ | |
1da177e4 LT |
158 | void iounmap(volatile void __iomem *addr) |
159 | { | |
bf5421c3 | 160 | struct vm_struct *p, *o; |
1da177e4 LT |
161 | |
162 | if (addr <= high_memory) | |
163 | return; | |
164 | if (addr >= phys_to_virt(ISA_START_ADDRESS) && | |
165 | addr < phys_to_virt(ISA_END_ADDRESS)) | |
166 | return; | |
167 | ||
b16b88e5 | 168 | addr = (volatile void __iomem *)(PAGE_MASK & (unsigned long __force)addr); |
bf5421c3 AK |
169 | /* Use the vm area unlocked, assuming the caller |
170 | ensures there isn't another iounmap for the same address | |
171 | in parallel. Reuse of the virtual address is prevented by | |
172 | leaving it in the global lists until we're done with it. | |
173 | cpa takes care of the direct mappings. */ | |
174 | read_lock(&vmlist_lock); | |
175 | for (p = vmlist; p; p = p->next) { | |
176 | if (p->addr == addr) | |
177 | break; | |
178 | } | |
179 | read_unlock(&vmlist_lock); | |
180 | ||
181 | if (!p) { | |
7856dfeb | 182 | printk("iounmap: bad address %p\n", addr); |
bf5421c3 AK |
183 | dump_stack(); |
184 | return; | |
185 | } | |
186 | ||
187 | /* Reset the direct mapping. Can block */ | |
188 | if (p->flags >> 20) | |
7856dfeb | 189 | ioremap_change_attr(p->phys_addr, p->size, 0); |
bf5421c3 AK |
190 | |
191 | /* Finally remove it */ | |
192 | o = remove_vm_area((void *)addr); | |
193 | BUG_ON(p != o || o == NULL); | |
1da177e4 LT |
194 | kfree(p); |
195 | } | |
2ee60e17 AK |
196 | EXPORT_SYMBOL(iounmap); |
197 |