Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * arch/i386/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> | |
129f6946 | 14 | #include <linux/module.h> |
a148ecfd | 15 | #include <linux/io.h> |
1da177e4 LT |
16 | #include <asm/fixmap.h> |
17 | #include <asm/cacheflush.h> | |
18 | #include <asm/tlbflush.h> | |
19 | #include <asm/pgtable.h> | |
20 | ||
21 | #define ISA_START_ADDRESS 0xa0000 | |
22 | #define ISA_END_ADDRESS 0x100000 | |
23 | ||
1da177e4 LT |
24 | /* |
25 | * Generic mapping function (not visible outside): | |
26 | */ | |
27 | ||
28 | /* | |
29 | * Remap an arbitrary physical address space into the kernel virtual | |
30 | * address space. Needed when the kernel wants to access high addresses | |
31 | * directly. | |
32 | * | |
33 | * NOTE! We need to allow non-page-aligned mappings too: we will obviously | |
34 | * have to convert them into an offset in a page-aligned mapping, but the | |
35 | * caller shouldn't need to know that small detail. | |
36 | */ | |
37 | void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) | |
38 | { | |
39 | void __iomem * addr; | |
40 | struct vm_struct * area; | |
41 | unsigned long offset, last_addr; | |
a148ecfd | 42 | pgprot_t prot; |
1da177e4 LT |
43 | |
44 | /* Don't allow wraparound or zero size */ | |
45 | last_addr = phys_addr + size - 1; | |
46 | if (!size || last_addr < phys_addr) | |
47 | return NULL; | |
48 | ||
49 | /* | |
50 | * Don't remap the low PCI/ISA area, it's always mapped.. | |
51 | */ | |
52 | if (phys_addr >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS) | |
53 | return (void __iomem *) phys_to_virt(phys_addr); | |
54 | ||
55 | /* | |
56 | * Don't allow anybody to remap normal RAM that we're using.. | |
57 | */ | |
58 | if (phys_addr <= virt_to_phys(high_memory - 1)) { | |
59 | char *t_addr, *t_end; | |
60 | struct page *page; | |
61 | ||
62 | t_addr = __va(phys_addr); | |
63 | t_end = t_addr + (size - 1); | |
64 | ||
65 | for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++) | |
66 | if(!PageReserved(page)) | |
67 | return NULL; | |
68 | } | |
69 | ||
a148ecfd HS |
70 | prot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY |
71 | | _PAGE_ACCESSED | flags); | |
72 | ||
1da177e4 LT |
73 | /* |
74 | * Mappings have to be page-aligned | |
75 | */ | |
76 | offset = phys_addr & ~PAGE_MASK; | |
77 | phys_addr &= PAGE_MASK; | |
78 | size = PAGE_ALIGN(last_addr+1) - phys_addr; | |
79 | ||
80 | /* | |
81 | * Ok, go for it.. | |
82 | */ | |
83 | area = get_vm_area(size, VM_IOREMAP | (flags << 20)); | |
84 | if (!area) | |
85 | return NULL; | |
86 | area->phys_addr = phys_addr; | |
87 | addr = (void __iomem *) area->addr; | |
88 | if (ioremap_page_range((unsigned long) addr, | |
a148ecfd | 89 | (unsigned long) addr + size, phys_addr, prot)) { |
1da177e4 LT |
90 | vunmap((void __force *) addr); |
91 | return NULL; | |
92 | } | |
93 | return (void __iomem *) (offset + (char __iomem *)addr); | |
94 | } | |
129f6946 | 95 | EXPORT_SYMBOL(__ioremap); |
1da177e4 LT |
96 | |
97 | /** | |
98 | * ioremap_nocache - map bus memory into CPU space | |
99 | * @offset: bus address of the memory | |
100 | * @size: size of the resource to map | |
101 | * | |
102 | * ioremap_nocache performs a platform specific sequence of operations to | |
103 | * make bus memory CPU accessible via the readb/readw/readl/writeb/ | |
104 | * writew/writel functions and the other mmio helpers. The returned | |
105 | * address is not guaranteed to be usable directly as a virtual | |
106 | * address. | |
107 | * | |
108 | * This version of ioremap ensures that the memory is marked uncachable | |
109 | * on the CPU as well as honouring existing caching rules from things like | |
110 | * the PCI bus. Note that there are other caches and buffers on many | |
111 | * busses. In particular driver authors should read up on PCI writes | |
112 | * | |
113 | * It's useful if some control registers are in such an area and | |
114 | * write combining or read caching is not desirable: | |
115 | * | |
116 | * Must be freed with iounmap. | |
117 | */ | |
118 | ||
119 | void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size) | |
120 | { | |
121 | unsigned long last_addr; | |
4138cc34 | 122 | void __iomem *p = __ioremap(phys_addr, size, _PAGE_PCD | _PAGE_PWT); |
1da177e4 LT |
123 | if (!p) |
124 | return p; | |
125 | ||
126 | /* Guaranteed to be > phys_addr, as per __ioremap() */ | |
127 | last_addr = phys_addr + size - 1; | |
128 | ||
129 | if (last_addr < virt_to_phys(high_memory) - 1) { | |
130 | struct page *ppage = virt_to_page(__va(phys_addr)); | |
131 | unsigned long npages; | |
132 | ||
133 | phys_addr &= PAGE_MASK; | |
134 | ||
135 | /* This might overflow and become zero.. */ | |
136 | last_addr = PAGE_ALIGN(last_addr); | |
137 | ||
138 | /* .. but that's ok, because modulo-2**n arithmetic will make | |
139 | * the page-aligned "last - first" come out right. | |
140 | */ | |
141 | npages = (last_addr - phys_addr) >> PAGE_SHIFT; | |
142 | ||
143 | if (change_page_attr(ppage, npages, PAGE_KERNEL_NOCACHE) < 0) { | |
144 | iounmap(p); | |
145 | p = NULL; | |
146 | } | |
147 | global_flush_tlb(); | |
148 | } | |
149 | ||
150 | return p; | |
151 | } | |
129f6946 | 152 | EXPORT_SYMBOL(ioremap_nocache); |
1da177e4 | 153 | |
bf5421c3 AK |
154 | /** |
155 | * iounmap - Free a IO remapping | |
156 | * @addr: virtual address from ioremap_* | |
157 | * | |
158 | * Caller must ensure there is only one unmapping for the same pointer. | |
159 | */ | |
1da177e4 LT |
160 | void iounmap(volatile void __iomem *addr) |
161 | { | |
bf5421c3 | 162 | struct vm_struct *p, *o; |
c23a4e96 AM |
163 | |
164 | if ((void __force *)addr <= high_memory) | |
1da177e4 LT |
165 | return; |
166 | ||
167 | /* | |
168 | * __ioremap special-cases the PCI/ISA range by not instantiating a | |
169 | * vm_area and by simply returning an address into the kernel mapping | |
170 | * of ISA space. So handle that here. | |
171 | */ | |
172 | if (addr >= phys_to_virt(ISA_START_ADDRESS) && | |
173 | addr < phys_to_virt(ISA_END_ADDRESS)) | |
174 | return; | |
175 | ||
b16b88e5 | 176 | addr = (volatile void __iomem *)(PAGE_MASK & (unsigned long __force)addr); |
bf5421c3 AK |
177 | |
178 | /* Use the vm area unlocked, assuming the caller | |
179 | ensures there isn't another iounmap for the same address | |
180 | in parallel. Reuse of the virtual address is prevented by | |
181 | leaving it in the global lists until we're done with it. | |
182 | cpa takes care of the direct mappings. */ | |
183 | read_lock(&vmlist_lock); | |
184 | for (p = vmlist; p; p = p->next) { | |
185 | if (p->addr == addr) | |
186 | break; | |
187 | } | |
188 | read_unlock(&vmlist_lock); | |
189 | ||
190 | if (!p) { | |
191 | printk("iounmap: bad address %p\n", addr); | |
c23a4e96 | 192 | dump_stack(); |
bf5421c3 | 193 | return; |
1da177e4 LT |
194 | } |
195 | ||
bf5421c3 | 196 | /* Reset the direct mapping. Can block */ |
1da177e4 | 197 | if ((p->flags >> 20) && p->phys_addr < virt_to_phys(high_memory) - 1) { |
1da177e4 | 198 | change_page_attr(virt_to_page(__va(p->phys_addr)), |
9585116b | 199 | get_vm_area_size(p) >> PAGE_SHIFT, |
1da177e4 LT |
200 | PAGE_KERNEL); |
201 | global_flush_tlb(); | |
202 | } | |
bf5421c3 AK |
203 | |
204 | /* Finally remove it */ | |
205 | o = remove_vm_area((void *)addr); | |
206 | BUG_ON(p != o || o == NULL); | |
1da177e4 LT |
207 | kfree(p); |
208 | } | |
129f6946 | 209 | EXPORT_SYMBOL(iounmap); |
1da177e4 | 210 | |
d18d6d65 IM |
211 | |
212 | int __initdata early_ioremap_debug; | |
213 | ||
214 | static int __init early_ioremap_debug_setup(char *str) | |
215 | { | |
216 | early_ioremap_debug = 1; | |
217 | ||
218 | return 1; | |
219 | } | |
220 | __setup("early_ioremap_debug", early_ioremap_debug_setup); | |
221 | ||
0947b2f3 HY |
222 | static __initdata int after_paging_init; |
223 | static __initdata unsigned long bm_pte[1024] | |
224 | __attribute__((aligned(PAGE_SIZE))); | |
225 | ||
beacfaac | 226 | static inline unsigned long * __init early_ioremap_pgd(unsigned long addr) |
0947b2f3 HY |
227 | { |
228 | return (unsigned long *)swapper_pg_dir + ((addr >> 22) & 1023); | |
229 | } | |
230 | ||
beacfaac | 231 | static inline unsigned long * __init early_ioremap_pte(unsigned long addr) |
0947b2f3 HY |
232 | { |
233 | return bm_pte + ((addr >> PAGE_SHIFT) & 1023); | |
234 | } | |
235 | ||
beacfaac | 236 | void __init early_ioremap_init(void) |
0947b2f3 HY |
237 | { |
238 | unsigned long *pgd; | |
239 | ||
d18d6d65 IM |
240 | if (early_ioremap_debug) |
241 | printk("early_ioremap_init()\n"); | |
242 | ||
beacfaac | 243 | pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN)); |
0947b2f3 HY |
244 | *pgd = __pa(bm_pte) | _PAGE_TABLE; |
245 | memset(bm_pte, 0, sizeof(bm_pte)); | |
beacfaac | 246 | BUG_ON(pgd != early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END))); |
0947b2f3 HY |
247 | } |
248 | ||
beacfaac | 249 | void __init early_ioremap_clear(void) |
0947b2f3 HY |
250 | { |
251 | unsigned long *pgd; | |
252 | ||
d18d6d65 IM |
253 | if (early_ioremap_debug) |
254 | printk("early_ioremap_clear()\n"); | |
255 | ||
beacfaac | 256 | pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN)); |
0947b2f3 HY |
257 | *pgd = 0; |
258 | __flush_tlb_all(); | |
259 | } | |
260 | ||
beacfaac | 261 | void __init early_ioremap_reset(void) |
0947b2f3 HY |
262 | { |
263 | enum fixed_addresses idx; | |
264 | unsigned long *pte, phys, addr; | |
265 | ||
266 | after_paging_init = 1; | |
64a8f852 | 267 | for (idx = FIX_BTMAP_BEGIN; idx >= FIX_BTMAP_END; idx--) { |
0947b2f3 | 268 | addr = fix_to_virt(idx); |
beacfaac | 269 | pte = early_ioremap_pte(addr); |
0947b2f3 HY |
270 | if (!*pte & _PAGE_PRESENT) { |
271 | phys = *pte & PAGE_MASK; | |
272 | set_fixmap(idx, phys); | |
273 | } | |
274 | } | |
275 | } | |
276 | ||
beacfaac | 277 | static void __init __early_set_fixmap(enum fixed_addresses idx, |
0947b2f3 HY |
278 | unsigned long phys, pgprot_t flags) |
279 | { | |
280 | unsigned long *pte, addr = __fix_to_virt(idx); | |
281 | ||
282 | if (idx >= __end_of_fixed_addresses) { | |
283 | BUG(); | |
284 | return; | |
285 | } | |
beacfaac | 286 | pte = early_ioremap_pte(addr); |
0947b2f3 HY |
287 | if (pgprot_val(flags)) |
288 | *pte = (phys & PAGE_MASK) | pgprot_val(flags); | |
289 | else | |
290 | *pte = 0; | |
291 | __flush_tlb_one(addr); | |
292 | } | |
293 | ||
beacfaac | 294 | static inline void __init early_set_fixmap(enum fixed_addresses idx, |
0947b2f3 HY |
295 | unsigned long phys) |
296 | { | |
297 | if (after_paging_init) | |
298 | set_fixmap(idx, phys); | |
299 | else | |
beacfaac | 300 | __early_set_fixmap(idx, phys, PAGE_KERNEL); |
0947b2f3 HY |
301 | } |
302 | ||
beacfaac | 303 | static inline void __init early_clear_fixmap(enum fixed_addresses idx) |
0947b2f3 HY |
304 | { |
305 | if (after_paging_init) | |
306 | clear_fixmap(idx); | |
307 | else | |
beacfaac | 308 | __early_set_fixmap(idx, 0, __pgprot(0)); |
0947b2f3 HY |
309 | } |
310 | ||
1b42f516 IM |
311 | |
312 | int __initdata early_ioremap_nested; | |
313 | ||
beacfaac | 314 | void __init *early_ioremap(unsigned long phys_addr, unsigned long size) |
1da177e4 LT |
315 | { |
316 | unsigned long offset, last_addr; | |
1b42f516 IM |
317 | unsigned int nrpages, nesting; |
318 | enum fixed_addresses idx0, idx; | |
319 | ||
320 | WARN_ON(system_state != SYSTEM_BOOTING); | |
321 | ||
322 | nesting = early_ioremap_nested; | |
d18d6d65 IM |
323 | if (early_ioremap_debug) { |
324 | printk("early_ioremap(%08lx, %08lx) [%d] => ", | |
325 | phys_addr, size, nesting); | |
326 | dump_stack(); | |
327 | } | |
1da177e4 LT |
328 | |
329 | /* Don't allow wraparound or zero size */ | |
330 | last_addr = phys_addr + size - 1; | |
bd796ed0 IM |
331 | if (!size || last_addr < phys_addr) { |
332 | WARN_ON(1); | |
1da177e4 | 333 | return NULL; |
bd796ed0 | 334 | } |
1da177e4 | 335 | |
bd796ed0 IM |
336 | if (nesting >= FIX_BTMAPS_NESTING) { |
337 | WARN_ON(1); | |
1b42f516 | 338 | return NULL; |
bd796ed0 | 339 | } |
1b42f516 | 340 | early_ioremap_nested++; |
1da177e4 LT |
341 | /* |
342 | * Mappings have to be page-aligned | |
343 | */ | |
344 | offset = phys_addr & ~PAGE_MASK; | |
345 | phys_addr &= PAGE_MASK; | |
346 | size = PAGE_ALIGN(last_addr) - phys_addr; | |
347 | ||
348 | /* | |
349 | * Mappings have to fit in the FIX_BTMAP area. | |
350 | */ | |
351 | nrpages = size >> PAGE_SHIFT; | |
bd796ed0 IM |
352 | if (nrpages > NR_FIX_BTMAPS) { |
353 | WARN_ON(1); | |
1da177e4 | 354 | return NULL; |
bd796ed0 | 355 | } |
1da177e4 LT |
356 | |
357 | /* | |
358 | * Ok, go for it.. | |
359 | */ | |
1b42f516 IM |
360 | idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting; |
361 | idx = idx0; | |
1da177e4 | 362 | while (nrpages > 0) { |
beacfaac | 363 | early_set_fixmap(idx, phys_addr); |
1da177e4 LT |
364 | phys_addr += PAGE_SIZE; |
365 | --idx; | |
366 | --nrpages; | |
367 | } | |
d18d6d65 IM |
368 | if (early_ioremap_debug) |
369 | printk(KERN_CONT "%08lx + %08lx\n", offset, fix_to_virt(idx0)); | |
1b42f516 IM |
370 | |
371 | return (void*) (offset + fix_to_virt(idx0)); | |
1da177e4 LT |
372 | } |
373 | ||
beacfaac | 374 | void __init early_iounmap(void *addr, unsigned long size) |
1da177e4 LT |
375 | { |
376 | unsigned long virt_addr; | |
377 | unsigned long offset; | |
378 | unsigned int nrpages; | |
379 | enum fixed_addresses idx; | |
1b42f516 IM |
380 | unsigned int nesting; |
381 | ||
382 | nesting = --early_ioremap_nested; | |
bd796ed0 | 383 | WARN_ON(nesting < 0); |
1da177e4 | 384 | |
d18d6d65 IM |
385 | if (early_ioremap_debug) { |
386 | printk("early_iounmap(%p, %08lx) [%d]\n", addr, size, nesting); | |
387 | dump_stack(); | |
388 | } | |
389 | ||
1da177e4 | 390 | virt_addr = (unsigned long)addr; |
bd796ed0 IM |
391 | if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) { |
392 | WARN_ON(1); | |
1da177e4 | 393 | return; |
bd796ed0 | 394 | } |
1da177e4 LT |
395 | offset = virt_addr & ~PAGE_MASK; |
396 | nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT; | |
397 | ||
1b42f516 | 398 | idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting; |
1da177e4 | 399 | while (nrpages > 0) { |
beacfaac | 400 | early_clear_fixmap(idx); |
1da177e4 LT |
401 | --idx; |
402 | --nrpages; | |
403 | } | |
404 | } | |
1b42f516 IM |
405 | |
406 | void __this_fixmap_does_not_exist(void) | |
407 | { | |
408 | WARN_ON(1); | |
409 | } |