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c1cc1552 CM |
1 | /* |
2 | * Based on arch/arm/mm/mmu.c | |
3 | * | |
4 | * Copyright (C) 1995-2005 Russell King | |
5 | * Copyright (C) 2012 ARM Ltd. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
18 | */ | |
19 | ||
20 | #include <linux/export.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/errno.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/mman.h> | |
25 | #include <linux/nodemask.h> | |
26 | #include <linux/memblock.h> | |
27 | #include <linux/fs.h> | |
28 | ||
29 | #include <asm/cputype.h> | |
30 | #include <asm/sections.h> | |
31 | #include <asm/setup.h> | |
32 | #include <asm/sizes.h> | |
33 | #include <asm/tlb.h> | |
34 | #include <asm/mmu_context.h> | |
35 | ||
36 | #include "mm.h" | |
37 | ||
38 | /* | |
39 | * Empty_zero_page is a special page that is used for zero-initialized data | |
40 | * and COW. | |
41 | */ | |
42 | struct page *empty_zero_page; | |
43 | EXPORT_SYMBOL(empty_zero_page); | |
44 | ||
45 | pgprot_t pgprot_default; | |
46 | EXPORT_SYMBOL(pgprot_default); | |
47 | ||
48 | static pmdval_t prot_sect_kernel; | |
49 | ||
50 | struct cachepolicy { | |
51 | const char policy[16]; | |
52 | u64 mair; | |
53 | u64 tcr; | |
54 | }; | |
55 | ||
56 | static struct cachepolicy cache_policies[] __initdata = { | |
57 | { | |
58 | .policy = "uncached", | |
59 | .mair = 0x44, /* inner, outer non-cacheable */ | |
60 | .tcr = TCR_IRGN_NC | TCR_ORGN_NC, | |
61 | }, { | |
62 | .policy = "writethrough", | |
63 | .mair = 0xaa, /* inner, outer write-through, read-allocate */ | |
64 | .tcr = TCR_IRGN_WT | TCR_ORGN_WT, | |
65 | }, { | |
66 | .policy = "writeback", | |
67 | .mair = 0xee, /* inner, outer write-back, read-allocate */ | |
68 | .tcr = TCR_IRGN_WBnWA | TCR_ORGN_WBnWA, | |
69 | } | |
70 | }; | |
71 | ||
72 | /* | |
73 | * These are useful for identifying cache coherency problems by allowing the | |
74 | * cache or the cache and writebuffer to be turned off. It changes the Normal | |
75 | * memory caching attributes in the MAIR_EL1 register. | |
76 | */ | |
77 | static int __init early_cachepolicy(char *p) | |
78 | { | |
79 | int i; | |
80 | u64 tmp; | |
81 | ||
82 | for (i = 0; i < ARRAY_SIZE(cache_policies); i++) { | |
83 | int len = strlen(cache_policies[i].policy); | |
84 | ||
85 | if (memcmp(p, cache_policies[i].policy, len) == 0) | |
86 | break; | |
87 | } | |
88 | if (i == ARRAY_SIZE(cache_policies)) { | |
89 | pr_err("ERROR: unknown or unsupported cache policy: %s\n", p); | |
90 | return 0; | |
91 | } | |
92 | ||
93 | flush_cache_all(); | |
94 | ||
95 | /* | |
96 | * Modify MT_NORMAL attributes in MAIR_EL1. | |
97 | */ | |
98 | asm volatile( | |
99 | " mrs %0, mair_el1\n" | |
100 | " bfi %0, %1, #%2, #8\n" | |
101 | " msr mair_el1, %0\n" | |
102 | " isb\n" | |
103 | : "=&r" (tmp) | |
104 | : "r" (cache_policies[i].mair), "i" (MT_NORMAL * 8)); | |
105 | ||
106 | /* | |
107 | * Modify TCR PTW cacheability attributes. | |
108 | */ | |
109 | asm volatile( | |
110 | " mrs %0, tcr_el1\n" | |
111 | " bic %0, %0, %2\n" | |
112 | " orr %0, %0, %1\n" | |
113 | " msr tcr_el1, %0\n" | |
114 | " isb\n" | |
115 | : "=&r" (tmp) | |
116 | : "r" (cache_policies[i].tcr), "r" (TCR_IRGN_MASK | TCR_ORGN_MASK)); | |
117 | ||
118 | flush_cache_all(); | |
119 | ||
120 | return 0; | |
121 | } | |
122 | early_param("cachepolicy", early_cachepolicy); | |
123 | ||
124 | /* | |
125 | * Adjust the PMD section entries according to the CPU in use. | |
126 | */ | |
127 | static void __init init_mem_pgprot(void) | |
128 | { | |
129 | pteval_t default_pgprot; | |
130 | int i; | |
131 | ||
132 | default_pgprot = PTE_ATTRINDX(MT_NORMAL); | |
133 | prot_sect_kernel = PMD_TYPE_SECT | PMD_SECT_AF | PMD_ATTRINDX(MT_NORMAL); | |
134 | ||
135 | #ifdef CONFIG_SMP | |
136 | /* | |
137 | * Mark memory with the "shared" attribute for SMP systems | |
138 | */ | |
139 | default_pgprot |= PTE_SHARED; | |
140 | prot_sect_kernel |= PMD_SECT_S; | |
141 | #endif | |
142 | ||
143 | for (i = 0; i < 16; i++) { | |
144 | unsigned long v = pgprot_val(protection_map[i]); | |
145 | protection_map[i] = __pgprot(v | default_pgprot); | |
146 | } | |
147 | ||
148 | pgprot_default = __pgprot(PTE_TYPE_PAGE | PTE_AF | default_pgprot); | |
149 | } | |
150 | ||
151 | pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, | |
152 | unsigned long size, pgprot_t vma_prot) | |
153 | { | |
154 | if (!pfn_valid(pfn)) | |
155 | return pgprot_noncached(vma_prot); | |
156 | else if (file->f_flags & O_SYNC) | |
157 | return pgprot_writecombine(vma_prot); | |
158 | return vma_prot; | |
159 | } | |
160 | EXPORT_SYMBOL(phys_mem_access_prot); | |
161 | ||
162 | static void __init *early_alloc(unsigned long sz) | |
163 | { | |
164 | void *ptr = __va(memblock_alloc(sz, sz)); | |
165 | memset(ptr, 0, sz); | |
166 | return ptr; | |
167 | } | |
168 | ||
169 | static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, | |
170 | unsigned long end, unsigned long pfn) | |
171 | { | |
172 | pte_t *pte; | |
173 | ||
174 | if (pmd_none(*pmd)) { | |
175 | pte = early_alloc(PTRS_PER_PTE * sizeof(pte_t)); | |
176 | __pmd_populate(pmd, __pa(pte), PMD_TYPE_TABLE); | |
177 | } | |
178 | BUG_ON(pmd_bad(*pmd)); | |
179 | ||
180 | pte = pte_offset_kernel(pmd, addr); | |
181 | do { | |
182 | set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); | |
183 | pfn++; | |
184 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
185 | } | |
186 | ||
187 | static void __init alloc_init_pmd(pud_t *pud, unsigned long addr, | |
188 | unsigned long end, phys_addr_t phys) | |
189 | { | |
190 | pmd_t *pmd; | |
191 | unsigned long next; | |
192 | ||
193 | /* | |
194 | * Check for initial section mappings in the pgd/pud and remove them. | |
195 | */ | |
196 | if (pud_none(*pud) || pud_bad(*pud)) { | |
197 | pmd = early_alloc(PTRS_PER_PMD * sizeof(pmd_t)); | |
198 | pud_populate(&init_mm, pud, pmd); | |
199 | } | |
200 | ||
201 | pmd = pmd_offset(pud, addr); | |
202 | do { | |
203 | next = pmd_addr_end(addr, end); | |
204 | /* try section mapping first */ | |
205 | if (((addr | next | phys) & ~SECTION_MASK) == 0) | |
206 | set_pmd(pmd, __pmd(phys | prot_sect_kernel)); | |
207 | else | |
208 | alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys)); | |
209 | phys += next - addr; | |
210 | } while (pmd++, addr = next, addr != end); | |
211 | } | |
212 | ||
213 | static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr, | |
214 | unsigned long end, unsigned long phys) | |
215 | { | |
216 | pud_t *pud = pud_offset(pgd, addr); | |
217 | unsigned long next; | |
218 | ||
219 | do { | |
220 | next = pud_addr_end(addr, end); | |
221 | alloc_init_pmd(pud, addr, next, phys); | |
222 | phys += next - addr; | |
223 | } while (pud++, addr = next, addr != end); | |
224 | } | |
225 | ||
226 | /* | |
227 | * Create the page directory entries and any necessary page tables for the | |
228 | * mapping specified by 'md'. | |
229 | */ | |
230 | static void __init create_mapping(phys_addr_t phys, unsigned long virt, | |
231 | phys_addr_t size) | |
232 | { | |
233 | unsigned long addr, length, end, next; | |
234 | pgd_t *pgd; | |
235 | ||
236 | if (virt < VMALLOC_START) { | |
237 | pr_warning("BUG: not creating mapping for 0x%016llx at 0x%016lx - outside kernel range\n", | |
238 | phys, virt); | |
239 | return; | |
240 | } | |
241 | ||
242 | addr = virt & PAGE_MASK; | |
243 | length = PAGE_ALIGN(size + (virt & ~PAGE_MASK)); | |
244 | ||
245 | pgd = pgd_offset_k(addr); | |
246 | end = addr + length; | |
247 | do { | |
248 | next = pgd_addr_end(addr, end); | |
249 | alloc_init_pud(pgd, addr, next, phys); | |
250 | phys += next - addr; | |
251 | } while (pgd++, addr = next, addr != end); | |
252 | } | |
253 | ||
254 | static void __init map_mem(void) | |
255 | { | |
256 | struct memblock_region *reg; | |
257 | ||
258 | /* map all the memory banks */ | |
259 | for_each_memblock(memory, reg) { | |
260 | phys_addr_t start = reg->base; | |
261 | phys_addr_t end = start + reg->size; | |
262 | ||
263 | if (start >= end) | |
264 | break; | |
265 | ||
266 | create_mapping(start, __phys_to_virt(start), end - start); | |
267 | } | |
268 | } | |
269 | ||
270 | /* | |
271 | * paging_init() sets up the page tables, initialises the zone memory | |
272 | * maps and sets up the zero page. | |
273 | */ | |
274 | void __init paging_init(void) | |
275 | { | |
276 | void *zero_page; | |
277 | ||
278 | /* | |
279 | * Maximum PGDIR_SIZE addressable via the initial direct kernel | |
280 | * mapping in swapper_pg_dir. | |
281 | */ | |
282 | memblock_set_current_limit((PHYS_OFFSET & PGDIR_MASK) + PGDIR_SIZE); | |
283 | ||
284 | init_mem_pgprot(); | |
285 | map_mem(); | |
286 | ||
287 | /* | |
288 | * Finally flush the caches and tlb to ensure that we're in a | |
289 | * consistent state. | |
290 | */ | |
291 | flush_cache_all(); | |
292 | flush_tlb_all(); | |
293 | ||
294 | /* allocate the zero page. */ | |
295 | zero_page = early_alloc(PAGE_SIZE); | |
296 | ||
297 | bootmem_init(); | |
298 | ||
299 | empty_zero_page = virt_to_page(zero_page); | |
300 | __flush_dcache_page(empty_zero_page); | |
301 | ||
302 | /* | |
303 | * TTBR0 is only used for the identity mapping at this stage. Make it | |
304 | * point to zero page to avoid speculatively fetching new entries. | |
305 | */ | |
306 | cpu_set_reserved_ttbr0(); | |
307 | flush_tlb_all(); | |
308 | } | |
309 | ||
310 | /* | |
311 | * Enable the identity mapping to allow the MMU disabling. | |
312 | */ | |
313 | void setup_mm_for_reboot(void) | |
314 | { | |
315 | cpu_switch_mm(idmap_pg_dir, &init_mm); | |
316 | flush_tlb_all(); | |
317 | } | |
318 | ||
319 | /* | |
320 | * Check whether a kernel address is valid (derived from arch/x86/). | |
321 | */ | |
322 | int kern_addr_valid(unsigned long addr) | |
323 | { | |
324 | pgd_t *pgd; | |
325 | pud_t *pud; | |
326 | pmd_t *pmd; | |
327 | pte_t *pte; | |
328 | ||
329 | if ((((long)addr) >> VA_BITS) != -1UL) | |
330 | return 0; | |
331 | ||
332 | pgd = pgd_offset_k(addr); | |
333 | if (pgd_none(*pgd)) | |
334 | return 0; | |
335 | ||
336 | pud = pud_offset(pgd, addr); | |
337 | if (pud_none(*pud)) | |
338 | return 0; | |
339 | ||
340 | pmd = pmd_offset(pud, addr); | |
341 | if (pmd_none(*pmd)) | |
342 | return 0; | |
343 | ||
344 | pte = pte_offset_kernel(pmd, addr); | |
345 | if (pte_none(*pte)) | |
346 | return 0; | |
347 | ||
348 | return pfn_valid(pte_pfn(*pte)); | |
349 | } | |
350 | #ifdef CONFIG_SPARSEMEM_VMEMMAP | |
351 | #ifdef CONFIG_ARM64_64K_PAGES | |
352 | int __meminit vmemmap_populate(struct page *start_page, | |
353 | unsigned long size, int node) | |
354 | { | |
355 | return vmemmap_populate_basepages(start_page, size, node); | |
356 | } | |
357 | #else /* !CONFIG_ARM64_64K_PAGES */ | |
358 | int __meminit vmemmap_populate(struct page *start_page, | |
359 | unsigned long size, int node) | |
360 | { | |
361 | unsigned long addr = (unsigned long)start_page; | |
362 | unsigned long end = (unsigned long)(start_page + size); | |
363 | unsigned long next; | |
364 | pgd_t *pgd; | |
365 | pud_t *pud; | |
366 | pmd_t *pmd; | |
367 | ||
368 | do { | |
369 | next = pmd_addr_end(addr, end); | |
370 | ||
371 | pgd = vmemmap_pgd_populate(addr, node); | |
372 | if (!pgd) | |
373 | return -ENOMEM; | |
374 | ||
375 | pud = vmemmap_pud_populate(pgd, addr, node); | |
376 | if (!pud) | |
377 | return -ENOMEM; | |
378 | ||
379 | pmd = pmd_offset(pud, addr); | |
380 | if (pmd_none(*pmd)) { | |
381 | void *p = NULL; | |
382 | ||
383 | p = vmemmap_alloc_block_buf(PMD_SIZE, node); | |
384 | if (!p) | |
385 | return -ENOMEM; | |
386 | ||
387 | set_pmd(pmd, __pmd(__pa(p) | prot_sect_kernel)); | |
388 | } else | |
389 | vmemmap_verify((pte_t *)pmd, node, addr, next); | |
390 | } while (addr = next, addr != end); | |
391 | ||
392 | return 0; | |
393 | } | |
394 | #endif /* CONFIG_ARM64_64K_PAGES */ | |
395 | #endif /* CONFIG_SPARSEMEM_VMEMMAP */ |