Commit | Line | Data |
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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> | |
fced80c7 | 27 | #include <linux/io.h> |
1da177e4 | 28 | |
0ba8b9b2 | 29 | #include <asm/cputype.h> |
1da177e4 | 30 | #include <asm/cacheflush.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 | |
69d3a84a HD |
45 | int ioremap_page(unsigned long virt, unsigned long phys, |
46 | const struct mem_type *mtype) | |
47 | { | |
d7461963 RK |
48 | return ioremap_page_range(virt, virt + PAGE_SIZE, phys, |
49 | __pgprot(mtype->prot_pte)); | |
69d3a84a HD |
50 | } |
51 | EXPORT_SYMBOL(ioremap_page); | |
ff0daca5 RK |
52 | |
53 | void __check_kvm_seq(struct mm_struct *mm) | |
54 | { | |
55 | unsigned int seq; | |
56 | ||
57 | do { | |
58 | seq = init_mm.context.kvm_seq; | |
59 | memcpy(pgd_offset(mm, VMALLOC_START), | |
60 | pgd_offset_k(VMALLOC_START), | |
61 | sizeof(pgd_t) * (pgd_index(VMALLOC_END) - | |
62 | pgd_index(VMALLOC_START))); | |
63 | mm->context.kvm_seq = seq; | |
64 | } while (seq != init_mm.context.kvm_seq); | |
65 | } | |
66 | ||
67 | #ifndef CONFIG_SMP | |
68 | /* | |
69 | * Section support is unsafe on SMP - If you iounmap and ioremap a region, | |
70 | * the other CPUs will not see this change until their next context switch. | |
71 | * Meanwhile, (eg) if an interrupt comes in on one of those other CPUs | |
72 | * which requires the new ioremap'd region to be referenced, the CPU will | |
73 | * reference the _old_ region. | |
74 | * | |
31aa8fd6 RK |
75 | * Note that get_vm_area_caller() allocates a guard 4K page, so we need to |
76 | * mask the size back to 1MB aligned or we will overflow in the loop below. | |
ff0daca5 RK |
77 | */ |
78 | static void unmap_area_sections(unsigned long virt, unsigned long size) | |
79 | { | |
24f11ec0 | 80 | unsigned long addr = virt, end = virt + (size & ~(SZ_1M - 1)); |
ff0daca5 | 81 | pgd_t *pgd; |
03a6b827 CM |
82 | pud_t *pud; |
83 | pmd_t *pmdp; | |
ff0daca5 RK |
84 | |
85 | flush_cache_vunmap(addr, end); | |
86 | pgd = pgd_offset_k(addr); | |
03a6b827 CM |
87 | pud = pud_offset(pgd, addr); |
88 | pmdp = pmd_offset(pud, addr); | |
ff0daca5 | 89 | do { |
03a6b827 | 90 | pmd_t pmd = *pmdp; |
ff0daca5 | 91 | |
ff0daca5 RK |
92 | if (!pmd_none(pmd)) { |
93 | /* | |
94 | * Clear the PMD from the page table, and | |
95 | * increment the kvm sequence so others | |
96 | * notice this change. | |
97 | * | |
98 | * Note: this is still racy on SMP machines. | |
99 | */ | |
100 | pmd_clear(pmdp); | |
101 | init_mm.context.kvm_seq++; | |
102 | ||
103 | /* | |
104 | * Free the page table, if there was one. | |
105 | */ | |
106 | if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE) | |
5e541973 | 107 | pte_free_kernel(&init_mm, pmd_page_vaddr(pmd)); |
ff0daca5 RK |
108 | } |
109 | ||
03a6b827 CM |
110 | addr += PMD_SIZE; |
111 | pmdp += 2; | |
ff0daca5 RK |
112 | } while (addr < end); |
113 | ||
114 | /* | |
115 | * Ensure that the active_mm is up to date - we want to | |
116 | * catch any use-after-iounmap cases. | |
117 | */ | |
118 | if (current->active_mm->context.kvm_seq != init_mm.context.kvm_seq) | |
119 | __check_kvm_seq(current->active_mm); | |
120 | ||
121 | flush_tlb_kernel_range(virt, end); | |
122 | } | |
123 | ||
124 | static int | |
125 | remap_area_sections(unsigned long virt, unsigned long pfn, | |
b29e9f5e | 126 | size_t size, const struct mem_type *type) |
ff0daca5 | 127 | { |
b29e9f5e | 128 | unsigned long addr = virt, end = virt + size; |
ff0daca5 | 129 | pgd_t *pgd; |
03a6b827 CM |
130 | pud_t *pud; |
131 | pmd_t *pmd; | |
ff0daca5 RK |
132 | |
133 | /* | |
134 | * Remove and free any PTE-based mapping, and | |
135 | * sync the current kernel mapping. | |
136 | */ | |
137 | unmap_area_sections(virt, size); | |
138 | ||
ff0daca5 | 139 | pgd = pgd_offset_k(addr); |
03a6b827 CM |
140 | pud = pud_offset(pgd, addr); |
141 | pmd = pmd_offset(pud, addr); | |
ff0daca5 | 142 | do { |
b29e9f5e | 143 | pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); |
ff0daca5 | 144 | pfn += SZ_1M >> PAGE_SHIFT; |
b29e9f5e | 145 | pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); |
ff0daca5 RK |
146 | pfn += SZ_1M >> PAGE_SHIFT; |
147 | flush_pmd_entry(pmd); | |
148 | ||
03a6b827 CM |
149 | addr += PMD_SIZE; |
150 | pmd += 2; | |
ff0daca5 RK |
151 | } while (addr < end); |
152 | ||
153 | return 0; | |
154 | } | |
a069c896 LB |
155 | |
156 | static int | |
157 | remap_area_supersections(unsigned long virt, unsigned long pfn, | |
b29e9f5e | 158 | size_t size, const struct mem_type *type) |
a069c896 | 159 | { |
b29e9f5e | 160 | unsigned long addr = virt, end = virt + size; |
a069c896 | 161 | pgd_t *pgd; |
03a6b827 CM |
162 | pud_t *pud; |
163 | pmd_t *pmd; | |
a069c896 LB |
164 | |
165 | /* | |
166 | * Remove and free any PTE-based mapping, and | |
167 | * sync the current kernel mapping. | |
168 | */ | |
169 | unmap_area_sections(virt, size); | |
170 | ||
a069c896 | 171 | pgd = pgd_offset_k(virt); |
03a6b827 CM |
172 | pud = pud_offset(pgd, addr); |
173 | pmd = pmd_offset(pud, addr); | |
a069c896 LB |
174 | do { |
175 | unsigned long super_pmd_val, i; | |
176 | ||
b29e9f5e RK |
177 | super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect | |
178 | PMD_SECT_SUPER; | |
a069c896 LB |
179 | super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20; |
180 | ||
181 | for (i = 0; i < 8; i++) { | |
a069c896 LB |
182 | pmd[0] = __pmd(super_pmd_val); |
183 | pmd[1] = __pmd(super_pmd_val); | |
184 | flush_pmd_entry(pmd); | |
185 | ||
03a6b827 CM |
186 | addr += PMD_SIZE; |
187 | pmd += 2; | |
a069c896 LB |
188 | } |
189 | ||
190 | pfn += SUPERSECTION_SIZE >> PAGE_SHIFT; | |
191 | } while (addr < end); | |
192 | ||
193 | return 0; | |
194 | } | |
ff0daca5 RK |
195 | #endif |
196 | ||
31aa8fd6 RK |
197 | void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn, |
198 | unsigned long offset, size_t size, unsigned int mtype, void *caller) | |
9d4ae727 | 199 | { |
b29e9f5e | 200 | const struct mem_type *type; |
ff0daca5 | 201 | int err; |
9d4ae727 DS |
202 | unsigned long addr; |
203 | struct vm_struct * area; | |
a069c896 LB |
204 | |
205 | /* | |
206 | * High mappings must be supersection aligned | |
207 | */ | |
208 | if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK)) | |
209 | return NULL; | |
9d4ae727 | 210 | |
309caa9c RK |
211 | /* |
212 | * Don't allow RAM to be mapped - this causes problems with ARMv6+ | |
213 | */ | |
67cfa23a RK |
214 | if (WARN_ON(pfn_valid(pfn))) |
215 | return NULL; | |
309caa9c | 216 | |
3603ab2b RK |
217 | type = get_mem_type(mtype); |
218 | if (!type) | |
219 | return NULL; | |
b29e9f5e | 220 | |
6d78b5f9 RK |
221 | /* |
222 | * Page align the mapping size, taking account of any offset. | |
223 | */ | |
224 | size = PAGE_ALIGN(offset + size); | |
c924aff8 | 225 | |
31aa8fd6 | 226 | area = get_vm_area_caller(size, VM_IOREMAP, caller); |
9d4ae727 DS |
227 | if (!area) |
228 | return NULL; | |
229 | addr = (unsigned long)area->addr; | |
ff0daca5 RK |
230 | |
231 | #ifndef CONFIG_SMP | |
412489af CM |
232 | if (DOMAIN_IO == 0 && |
233 | (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) || | |
4a56c1e4 | 234 | cpu_is_xsc3()) && pfn >= 0x100000 && |
a069c896 LB |
235 | !((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) { |
236 | area->flags |= VM_ARM_SECTION_MAPPING; | |
b29e9f5e | 237 | err = remap_area_supersections(addr, pfn, size, type); |
a069c896 | 238 | } else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) { |
ff0daca5 | 239 | area->flags |= VM_ARM_SECTION_MAPPING; |
b29e9f5e | 240 | err = remap_area_sections(addr, pfn, size, type); |
ff0daca5 RK |
241 | } else |
242 | #endif | |
d7461963 RK |
243 | err = ioremap_page_range(addr, addr + size, __pfn_to_phys(pfn), |
244 | __pgprot(type->prot_pte)); | |
ff0daca5 RK |
245 | |
246 | if (err) { | |
478922c2 | 247 | vunmap((void *)addr); |
9d4ae727 DS |
248 | return NULL; |
249 | } | |
ff0daca5 RK |
250 | |
251 | flush_cache_vmap(addr, addr + size); | |
252 | return (void __iomem *) (offset + addr); | |
9d4ae727 | 253 | } |
9d4ae727 | 254 | |
31aa8fd6 RK |
255 | void __iomem *__arm_ioremap_caller(unsigned long phys_addr, size_t size, |
256 | unsigned int mtype, void *caller) | |
1da177e4 | 257 | { |
9d4ae727 DS |
258 | unsigned long last_addr; |
259 | unsigned long offset = phys_addr & ~PAGE_MASK; | |
260 | unsigned long pfn = __phys_to_pfn(phys_addr); | |
1da177e4 | 261 | |
9d4ae727 DS |
262 | /* |
263 | * Don't allow wraparound or zero size | |
264 | */ | |
1da177e4 LT |
265 | last_addr = phys_addr + size - 1; |
266 | if (!size || last_addr < phys_addr) | |
267 | return NULL; | |
268 | ||
31aa8fd6 RK |
269 | return __arm_ioremap_pfn_caller(pfn, offset, size, mtype, |
270 | caller); | |
271 | } | |
272 | ||
273 | /* | |
274 | * Remap an arbitrary physical address space into the kernel virtual | |
275 | * address space. Needed when the kernel wants to access high addresses | |
276 | * directly. | |
277 | * | |
278 | * NOTE! We need to allow non-page-aligned mappings too: we will obviously | |
279 | * have to convert them into an offset in a page-aligned mapping, but the | |
280 | * caller shouldn't need to know that small detail. | |
281 | */ | |
282 | void __iomem * | |
283 | __arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size, | |
284 | unsigned int mtype) | |
285 | { | |
286 | return __arm_ioremap_pfn_caller(pfn, offset, size, mtype, | |
287 | __builtin_return_address(0)); | |
288 | } | |
289 | EXPORT_SYMBOL(__arm_ioremap_pfn); | |
290 | ||
291 | void __iomem * | |
292 | __arm_ioremap(unsigned long phys_addr, size_t size, unsigned int mtype) | |
293 | { | |
294 | return __arm_ioremap_caller(phys_addr, size, mtype, | |
295 | __builtin_return_address(0)); | |
1da177e4 | 296 | } |
3603ab2b | 297 | EXPORT_SYMBOL(__arm_ioremap); |
1da177e4 | 298 | |
6c5482d5 TL |
299 | /* |
300 | * Remap an arbitrary physical address space into the kernel virtual | |
301 | * address space as memory. Needed when the kernel wants to execute | |
302 | * code in external memory. This is needed for reprogramming source | |
303 | * clocks that would affect normal memory for example. Please see | |
304 | * CONFIG_GENERIC_ALLOCATOR for allocating external memory. | |
305 | */ | |
306 | void __iomem * | |
307 | __arm_ioremap_exec(unsigned long phys_addr, size_t size, bool cached) | |
308 | { | |
309 | unsigned int mtype; | |
310 | ||
311 | if (cached) | |
312 | mtype = MT_MEMORY; | |
313 | else | |
314 | mtype = MT_MEMORY_NONCACHED; | |
315 | ||
316 | return __arm_ioremap_caller(phys_addr, size, mtype, | |
317 | __builtin_return_address(0)); | |
318 | } | |
319 | ||
09d9bae0 | 320 | void __iounmap(volatile void __iomem *io_addr) |
1da177e4 | 321 | { |
09d9bae0 | 322 | void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr); |
ceaccbd2 | 323 | #ifndef CONFIG_SMP |
ff0daca5 | 324 | struct vm_struct **p, *tmp; |
ff0daca5 | 325 | |
ff0daca5 RK |
326 | /* |
327 | * If this is a section based mapping we need to handle it | |
6cbdc8c5 | 328 | * specially as the VM subsystem does not know how to handle |
ff0daca5 RK |
329 | * such a beast. We need the lock here b/c we need to clear |
330 | * all the mappings before the area can be reclaimed | |
331 | * by someone else. | |
332 | */ | |
333 | write_lock(&vmlist_lock); | |
334 | for (p = &vmlist ; (tmp = *p) ; p = &tmp->next) { | |
09d9bae0 | 335 | if ((tmp->flags & VM_IOREMAP) && (tmp->addr == addr)) { |
ff0daca5 | 336 | if (tmp->flags & VM_ARM_SECTION_MAPPING) { |
ff0daca5 RK |
337 | unmap_area_sections((unsigned long)tmp->addr, |
338 | tmp->size); | |
ff0daca5 RK |
339 | } |
340 | break; | |
341 | } | |
342 | } | |
343 | write_unlock(&vmlist_lock); | |
7cddc397 | 344 | #endif |
ff0daca5 | 345 | |
24f11ec0 | 346 | vunmap(addr); |
1da177e4 LT |
347 | } |
348 | EXPORT_SYMBOL(__iounmap); |