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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/mm/ioremap.c | |
3 | * | |
4 | * Re-map IO memory to kernel address space so that we can access it. | |
5 | * | |
6 | * (C) Copyright 1995 1996 Linus Torvalds | |
7 | * | |
8 | * Hacked for ARM by Phil Blundell <philb@gnu.org> | |
9 | * Hacked to allow all architectures to build, and various cleanups | |
10 | * by Russell King | |
11 | * | |
12 | * This allows a driver to remap an arbitrary region of bus memory into | |
13 | * virtual space. One should *only* use readl, writel, memcpy_toio and | |
14 | * so on with such remapped areas. | |
15 | * | |
16 | * Because the ARM only has a 32-bit address space we can't address the | |
17 | * whole of the (physical) PCI space at once. PCI huge-mode addressing | |
18 | * allows us to circumvent this restriction by splitting PCI space into | |
19 | * two 2GB chunks and mapping only one at a time into processor memory. | |
20 | * We use MMU protection domains to trap any attempt to access the bank | |
21 | * that is not currently mapped. (This isn't fully implemented yet.) | |
22 | */ | |
23 | #include <linux/module.h> | |
24 | #include <linux/errno.h> | |
25 | #include <linux/mm.h> | |
26 | #include <linux/vmalloc.h> | |
27 | ||
0ba8b9b2 | 28 | #include <asm/cputype.h> |
1da177e4 LT |
29 | #include <asm/cacheflush.h> |
30 | #include <asm/io.h> | |
ff0daca5 RK |
31 | #include <asm/mmu_context.h> |
32 | #include <asm/pgalloc.h> | |
1da177e4 | 33 | #include <asm/tlbflush.h> |
ff0daca5 RK |
34 | #include <asm/sizes.h> |
35 | ||
b29e9f5e RK |
36 | #include <asm/mach/map.h> |
37 | #include "mm.h" | |
38 | ||
ff0daca5 | 39 | /* |
a069c896 LB |
40 | * Used by ioremap() and iounmap() code to mark (super)section-mapped |
41 | * I/O regions in vm_struct->flags field. | |
ff0daca5 RK |
42 | */ |
43 | #define VM_ARM_SECTION_MAPPING 0x80000000 | |
1da177e4 | 44 | |
da2c12a2 | 45 | static int remap_area_pte(pmd_t *pmd, unsigned long addr, unsigned long end, |
b29e9f5e | 46 | unsigned long phys_addr, const struct mem_type *type) |
1da177e4 | 47 | { |
b29e9f5e | 48 | pgprot_t prot = __pgprot(type->prot_pte); |
da2c12a2 RK |
49 | pte_t *pte; |
50 | ||
51 | pte = pte_alloc_kernel(pmd, addr); | |
52 | if (!pte) | |
53 | return -ENOMEM; | |
1da177e4 | 54 | |
1da177e4 LT |
55 | do { |
56 | if (!pte_none(*pte)) | |
57 | goto bad; | |
58 | ||
c172cc92 RK |
59 | set_pte_ext(pte, pfn_pte(phys_addr >> PAGE_SHIFT, prot), |
60 | type->prot_pte_ext); | |
1da177e4 | 61 | phys_addr += PAGE_SIZE; |
da2c12a2 RK |
62 | } while (pte++, addr += PAGE_SIZE, addr != end); |
63 | return 0; | |
1da177e4 LT |
64 | |
65 | bad: | |
da2c12a2 | 66 | printk(KERN_CRIT "remap_area_pte: page already exists\n"); |
1da177e4 LT |
67 | BUG(); |
68 | } | |
69 | ||
da2c12a2 RK |
70 | static inline int remap_area_pmd(pgd_t *pgd, unsigned long addr, |
71 | unsigned long end, unsigned long phys_addr, | |
b29e9f5e | 72 | const struct mem_type *type) |
1da177e4 | 73 | { |
da2c12a2 RK |
74 | unsigned long next; |
75 | pmd_t *pmd; | |
76 | int ret = 0; | |
1da177e4 | 77 | |
da2c12a2 RK |
78 | pmd = pmd_alloc(&init_mm, pgd, addr); |
79 | if (!pmd) | |
80 | return -ENOMEM; | |
1da177e4 | 81 | |
1da177e4 | 82 | do { |
da2c12a2 | 83 | next = pmd_addr_end(addr, end); |
b29e9f5e | 84 | ret = remap_area_pte(pmd, addr, next, phys_addr, type); |
da2c12a2 RK |
85 | if (ret) |
86 | return ret; | |
87 | phys_addr += next - addr; | |
88 | } while (pmd++, addr = next, addr != end); | |
89 | return ret; | |
1da177e4 LT |
90 | } |
91 | ||
da2c12a2 | 92 | static int remap_area_pages(unsigned long start, unsigned long pfn, |
b29e9f5e | 93 | size_t size, const struct mem_type *type) |
1da177e4 | 94 | { |
da2c12a2 RK |
95 | unsigned long addr = start; |
96 | unsigned long next, end = start + size; | |
9d4ae727 | 97 | unsigned long phys_addr = __pfn_to_phys(pfn); |
da2c12a2 | 98 | pgd_t *pgd; |
1da177e4 | 99 | int err = 0; |
1da177e4 | 100 | |
da2c12a2 RK |
101 | BUG_ON(addr >= end); |
102 | pgd = pgd_offset_k(addr); | |
1da177e4 | 103 | do { |
da2c12a2 | 104 | next = pgd_addr_end(addr, end); |
b29e9f5e | 105 | err = remap_area_pmd(pgd, addr, next, phys_addr, type); |
da2c12a2 | 106 | if (err) |
1da177e4 | 107 | break; |
da2c12a2 RK |
108 | phys_addr += next - addr; |
109 | } while (pgd++, addr = next, addr != end); | |
1da177e4 | 110 | |
1da177e4 LT |
111 | return err; |
112 | } | |
113 | ||
ff0daca5 RK |
114 | |
115 | void __check_kvm_seq(struct mm_struct *mm) | |
116 | { | |
117 | unsigned int seq; | |
118 | ||
119 | do { | |
120 | seq = init_mm.context.kvm_seq; | |
121 | memcpy(pgd_offset(mm, VMALLOC_START), | |
122 | pgd_offset_k(VMALLOC_START), | |
123 | sizeof(pgd_t) * (pgd_index(VMALLOC_END) - | |
124 | pgd_index(VMALLOC_START))); | |
125 | mm->context.kvm_seq = seq; | |
126 | } while (seq != init_mm.context.kvm_seq); | |
127 | } | |
128 | ||
129 | #ifndef CONFIG_SMP | |
130 | /* | |
131 | * Section support is unsafe on SMP - If you iounmap and ioremap a region, | |
132 | * the other CPUs will not see this change until their next context switch. | |
133 | * Meanwhile, (eg) if an interrupt comes in on one of those other CPUs | |
134 | * which requires the new ioremap'd region to be referenced, the CPU will | |
135 | * reference the _old_ region. | |
136 | * | |
137 | * Note that get_vm_area() allocates a guard 4K page, so we need to mask | |
138 | * the size back to 1MB aligned or we will overflow in the loop below. | |
139 | */ | |
140 | static void unmap_area_sections(unsigned long virt, unsigned long size) | |
141 | { | |
142 | unsigned long addr = virt, end = virt + (size & ~SZ_1M); | |
143 | pgd_t *pgd; | |
144 | ||
145 | flush_cache_vunmap(addr, end); | |
146 | pgd = pgd_offset_k(addr); | |
147 | do { | |
148 | pmd_t pmd, *pmdp = pmd_offset(pgd, addr); | |
149 | ||
150 | pmd = *pmdp; | |
151 | if (!pmd_none(pmd)) { | |
152 | /* | |
153 | * Clear the PMD from the page table, and | |
154 | * increment the kvm sequence so others | |
155 | * notice this change. | |
156 | * | |
157 | * Note: this is still racy on SMP machines. | |
158 | */ | |
159 | pmd_clear(pmdp); | |
160 | init_mm.context.kvm_seq++; | |
161 | ||
162 | /* | |
163 | * Free the page table, if there was one. | |
164 | */ | |
165 | if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE) | |
5e541973 | 166 | pte_free_kernel(&init_mm, pmd_page_vaddr(pmd)); |
ff0daca5 RK |
167 | } |
168 | ||
169 | addr += PGDIR_SIZE; | |
170 | pgd++; | |
171 | } while (addr < end); | |
172 | ||
173 | /* | |
174 | * Ensure that the active_mm is up to date - we want to | |
175 | * catch any use-after-iounmap cases. | |
176 | */ | |
177 | if (current->active_mm->context.kvm_seq != init_mm.context.kvm_seq) | |
178 | __check_kvm_seq(current->active_mm); | |
179 | ||
180 | flush_tlb_kernel_range(virt, end); | |
181 | } | |
182 | ||
183 | static int | |
184 | remap_area_sections(unsigned long virt, unsigned long pfn, | |
b29e9f5e | 185 | size_t size, const struct mem_type *type) |
ff0daca5 | 186 | { |
b29e9f5e | 187 | unsigned long addr = virt, end = virt + size; |
ff0daca5 RK |
188 | pgd_t *pgd; |
189 | ||
190 | /* | |
191 | * Remove and free any PTE-based mapping, and | |
192 | * sync the current kernel mapping. | |
193 | */ | |
194 | unmap_area_sections(virt, size); | |
195 | ||
ff0daca5 RK |
196 | pgd = pgd_offset_k(addr); |
197 | do { | |
198 | pmd_t *pmd = pmd_offset(pgd, addr); | |
199 | ||
b29e9f5e | 200 | pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); |
ff0daca5 | 201 | pfn += SZ_1M >> PAGE_SHIFT; |
b29e9f5e | 202 | pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); |
ff0daca5 RK |
203 | pfn += SZ_1M >> PAGE_SHIFT; |
204 | flush_pmd_entry(pmd); | |
205 | ||
206 | addr += PGDIR_SIZE; | |
207 | pgd++; | |
208 | } while (addr < end); | |
209 | ||
210 | return 0; | |
211 | } | |
a069c896 LB |
212 | |
213 | static int | |
214 | remap_area_supersections(unsigned long virt, unsigned long pfn, | |
b29e9f5e | 215 | size_t size, const struct mem_type *type) |
a069c896 | 216 | { |
b29e9f5e | 217 | unsigned long addr = virt, end = virt + size; |
a069c896 LB |
218 | pgd_t *pgd; |
219 | ||
220 | /* | |
221 | * Remove and free any PTE-based mapping, and | |
222 | * sync the current kernel mapping. | |
223 | */ | |
224 | unmap_area_sections(virt, size); | |
225 | ||
a069c896 LB |
226 | pgd = pgd_offset_k(virt); |
227 | do { | |
228 | unsigned long super_pmd_val, i; | |
229 | ||
b29e9f5e RK |
230 | super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect | |
231 | PMD_SECT_SUPER; | |
a069c896 LB |
232 | super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20; |
233 | ||
234 | for (i = 0; i < 8; i++) { | |
235 | pmd_t *pmd = pmd_offset(pgd, addr); | |
236 | ||
237 | pmd[0] = __pmd(super_pmd_val); | |
238 | pmd[1] = __pmd(super_pmd_val); | |
239 | flush_pmd_entry(pmd); | |
240 | ||
241 | addr += PGDIR_SIZE; | |
242 | pgd++; | |
243 | } | |
244 | ||
245 | pfn += SUPERSECTION_SIZE >> PAGE_SHIFT; | |
246 | } while (addr < end); | |
247 | ||
248 | return 0; | |
249 | } | |
ff0daca5 RK |
250 | #endif |
251 | ||
252 | ||
1da177e4 LT |
253 | /* |
254 | * Remap an arbitrary physical address space into the kernel virtual | |
255 | * address space. Needed when the kernel wants to access high addresses | |
256 | * directly. | |
257 | * | |
258 | * NOTE! We need to allow non-page-aligned mappings too: we will obviously | |
259 | * have to convert them into an offset in a page-aligned mapping, but the | |
260 | * caller shouldn't need to know that small detail. | |
261 | * | |
262 | * 'flags' are the extra L_PTE_ flags that you want to specify for this | |
4baa9922 | 263 | * mapping. See <asm/pgtable.h> for more information. |
1da177e4 | 264 | */ |
9d4ae727 | 265 | void __iomem * |
3603ab2b RK |
266 | __arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size, |
267 | unsigned int mtype) | |
9d4ae727 | 268 | { |
b29e9f5e | 269 | const struct mem_type *type; |
ff0daca5 | 270 | int err; |
9d4ae727 DS |
271 | unsigned long addr; |
272 | struct vm_struct * area; | |
a069c896 LB |
273 | |
274 | /* | |
275 | * High mappings must be supersection aligned | |
276 | */ | |
277 | if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK)) | |
278 | return NULL; | |
9d4ae727 | 279 | |
3603ab2b RK |
280 | type = get_mem_type(mtype); |
281 | if (!type) | |
282 | return NULL; | |
b29e9f5e | 283 | |
6d78b5f9 RK |
284 | /* |
285 | * Page align the mapping size, taking account of any offset. | |
286 | */ | |
287 | size = PAGE_ALIGN(offset + size); | |
c924aff8 | 288 | |
9d4ae727 DS |
289 | area = get_vm_area(size, VM_IOREMAP); |
290 | if (!area) | |
291 | return NULL; | |
292 | addr = (unsigned long)area->addr; | |
ff0daca5 RK |
293 | |
294 | #ifndef CONFIG_SMP | |
412489af CM |
295 | if (DOMAIN_IO == 0 && |
296 | (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) || | |
4a56c1e4 | 297 | cpu_is_xsc3()) && pfn >= 0x100000 && |
a069c896 LB |
298 | !((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) { |
299 | area->flags |= VM_ARM_SECTION_MAPPING; | |
b29e9f5e | 300 | err = remap_area_supersections(addr, pfn, size, type); |
a069c896 | 301 | } else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) { |
ff0daca5 | 302 | area->flags |= VM_ARM_SECTION_MAPPING; |
b29e9f5e | 303 | err = remap_area_sections(addr, pfn, size, type); |
ff0daca5 RK |
304 | } else |
305 | #endif | |
b29e9f5e | 306 | err = remap_area_pages(addr, pfn, size, type); |
ff0daca5 RK |
307 | |
308 | if (err) { | |
478922c2 | 309 | vunmap((void *)addr); |
9d4ae727 DS |
310 | return NULL; |
311 | } | |
ff0daca5 RK |
312 | |
313 | flush_cache_vmap(addr, addr + size); | |
314 | return (void __iomem *) (offset + addr); | |
9d4ae727 | 315 | } |
3603ab2b | 316 | EXPORT_SYMBOL(__arm_ioremap_pfn); |
9d4ae727 | 317 | |
1da177e4 | 318 | void __iomem * |
3603ab2b | 319 | __arm_ioremap(unsigned long phys_addr, size_t size, unsigned int mtype) |
1da177e4 | 320 | { |
9d4ae727 DS |
321 | unsigned long last_addr; |
322 | unsigned long offset = phys_addr & ~PAGE_MASK; | |
323 | unsigned long pfn = __phys_to_pfn(phys_addr); | |
1da177e4 | 324 | |
9d4ae727 DS |
325 | /* |
326 | * Don't allow wraparound or zero size | |
327 | */ | |
1da177e4 LT |
328 | last_addr = phys_addr + size - 1; |
329 | if (!size || last_addr < phys_addr) | |
330 | return NULL; | |
331 | ||
3603ab2b | 332 | return __arm_ioremap_pfn(pfn, offset, size, mtype); |
1da177e4 | 333 | } |
3603ab2b | 334 | EXPORT_SYMBOL(__arm_ioremap); |
1da177e4 | 335 | |
09d9bae0 | 336 | void __iounmap(volatile void __iomem *io_addr) |
1da177e4 | 337 | { |
09d9bae0 | 338 | void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr); |
ceaccbd2 | 339 | #ifndef CONFIG_SMP |
ff0daca5 | 340 | struct vm_struct **p, *tmp; |
ceaccbd2 | 341 | #endif |
ff0daca5 RK |
342 | unsigned int section_mapping = 0; |
343 | ||
7cddc397 | 344 | #ifndef CONFIG_SMP |
ff0daca5 RK |
345 | /* |
346 | * If this is a section based mapping we need to handle it | |
6cbdc8c5 | 347 | * specially as the VM subsystem does not know how to handle |
ff0daca5 RK |
348 | * such a beast. We need the lock here b/c we need to clear |
349 | * all the mappings before the area can be reclaimed | |
350 | * by someone else. | |
351 | */ | |
352 | write_lock(&vmlist_lock); | |
353 | for (p = &vmlist ; (tmp = *p) ; p = &tmp->next) { | |
09d9bae0 | 354 | if ((tmp->flags & VM_IOREMAP) && (tmp->addr == addr)) { |
ff0daca5 RK |
355 | if (tmp->flags & VM_ARM_SECTION_MAPPING) { |
356 | *p = tmp->next; | |
357 | unmap_area_sections((unsigned long)tmp->addr, | |
358 | tmp->size); | |
359 | kfree(tmp); | |
360 | section_mapping = 1; | |
361 | } | |
362 | break; | |
363 | } | |
364 | } | |
365 | write_unlock(&vmlist_lock); | |
7cddc397 | 366 | #endif |
ff0daca5 RK |
367 | |
368 | if (!section_mapping) | |
09d9bae0 | 369 | vunmap(addr); |
1da177e4 LT |
370 | } |
371 | EXPORT_SYMBOL(__iounmap); |