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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> | |
2475ff9d | 28 | #include <linux/io.h> |
c1cc1552 CM |
29 | |
30 | #include <asm/cputype.h> | |
31 | #include <asm/sections.h> | |
32 | #include <asm/setup.h> | |
33 | #include <asm/sizes.h> | |
34 | #include <asm/tlb.h> | |
c79b954b | 35 | #include <asm/memblock.h> |
c1cc1552 CM |
36 | #include <asm/mmu_context.h> |
37 | ||
38 | #include "mm.h" | |
39 | ||
40 | /* | |
41 | * Empty_zero_page is a special page that is used for zero-initialized data | |
42 | * and COW. | |
43 | */ | |
44 | struct page *empty_zero_page; | |
45 | EXPORT_SYMBOL(empty_zero_page); | |
46 | ||
c1cc1552 CM |
47 | struct cachepolicy { |
48 | const char policy[16]; | |
49 | u64 mair; | |
50 | u64 tcr; | |
51 | }; | |
52 | ||
53 | static struct cachepolicy cache_policies[] __initdata = { | |
54 | { | |
55 | .policy = "uncached", | |
56 | .mair = 0x44, /* inner, outer non-cacheable */ | |
57 | .tcr = TCR_IRGN_NC | TCR_ORGN_NC, | |
58 | }, { | |
59 | .policy = "writethrough", | |
60 | .mair = 0xaa, /* inner, outer write-through, read-allocate */ | |
61 | .tcr = TCR_IRGN_WT | TCR_ORGN_WT, | |
62 | }, { | |
63 | .policy = "writeback", | |
64 | .mair = 0xee, /* inner, outer write-back, read-allocate */ | |
65 | .tcr = TCR_IRGN_WBnWA | TCR_ORGN_WBnWA, | |
66 | } | |
67 | }; | |
68 | ||
69 | /* | |
70 | * These are useful for identifying cache coherency problems by allowing the | |
71 | * cache or the cache and writebuffer to be turned off. It changes the Normal | |
72 | * memory caching attributes in the MAIR_EL1 register. | |
73 | */ | |
74 | static int __init early_cachepolicy(char *p) | |
75 | { | |
76 | int i; | |
77 | u64 tmp; | |
78 | ||
79 | for (i = 0; i < ARRAY_SIZE(cache_policies); i++) { | |
80 | int len = strlen(cache_policies[i].policy); | |
81 | ||
82 | if (memcmp(p, cache_policies[i].policy, len) == 0) | |
83 | break; | |
84 | } | |
85 | if (i == ARRAY_SIZE(cache_policies)) { | |
86 | pr_err("ERROR: unknown or unsupported cache policy: %s\n", p); | |
87 | return 0; | |
88 | } | |
89 | ||
90 | flush_cache_all(); | |
91 | ||
92 | /* | |
93 | * Modify MT_NORMAL attributes in MAIR_EL1. | |
94 | */ | |
95 | asm volatile( | |
96 | " mrs %0, mair_el1\n" | |
97 | " bfi %0, %1, #%2, #8\n" | |
98 | " msr mair_el1, %0\n" | |
99 | " isb\n" | |
100 | : "=&r" (tmp) | |
101 | : "r" (cache_policies[i].mair), "i" (MT_NORMAL * 8)); | |
102 | ||
103 | /* | |
104 | * Modify TCR PTW cacheability attributes. | |
105 | */ | |
106 | asm volatile( | |
107 | " mrs %0, tcr_el1\n" | |
108 | " bic %0, %0, %2\n" | |
109 | " orr %0, %0, %1\n" | |
110 | " msr tcr_el1, %0\n" | |
111 | " isb\n" | |
112 | : "=&r" (tmp) | |
113 | : "r" (cache_policies[i].tcr), "r" (TCR_IRGN_MASK | TCR_ORGN_MASK)); | |
114 | ||
115 | flush_cache_all(); | |
116 | ||
117 | return 0; | |
118 | } | |
119 | early_param("cachepolicy", early_cachepolicy); | |
120 | ||
c1cc1552 CM |
121 | pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, |
122 | unsigned long size, pgprot_t vma_prot) | |
123 | { | |
124 | if (!pfn_valid(pfn)) | |
125 | return pgprot_noncached(vma_prot); | |
126 | else if (file->f_flags & O_SYNC) | |
127 | return pgprot_writecombine(vma_prot); | |
128 | return vma_prot; | |
129 | } | |
130 | EXPORT_SYMBOL(phys_mem_access_prot); | |
131 | ||
132 | static void __init *early_alloc(unsigned long sz) | |
133 | { | |
134 | void *ptr = __va(memblock_alloc(sz, sz)); | |
135 | memset(ptr, 0, sz); | |
136 | return ptr; | |
137 | } | |
138 | ||
139 | static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, | |
d7ecbddf MS |
140 | unsigned long end, unsigned long pfn, |
141 | pgprot_t prot) | |
c1cc1552 CM |
142 | { |
143 | pte_t *pte; | |
144 | ||
145 | if (pmd_none(*pmd)) { | |
146 | pte = early_alloc(PTRS_PER_PTE * sizeof(pte_t)); | |
147 | __pmd_populate(pmd, __pa(pte), PMD_TYPE_TABLE); | |
148 | } | |
149 | BUG_ON(pmd_bad(*pmd)); | |
150 | ||
151 | pte = pte_offset_kernel(pmd, addr); | |
152 | do { | |
d7ecbddf | 153 | set_pte(pte, pfn_pte(pfn, prot)); |
c1cc1552 CM |
154 | pfn++; |
155 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
156 | } | |
157 | ||
158 | static void __init alloc_init_pmd(pud_t *pud, unsigned long addr, | |
d7ecbddf MS |
159 | unsigned long end, phys_addr_t phys, |
160 | int map_io) | |
c1cc1552 CM |
161 | { |
162 | pmd_t *pmd; | |
163 | unsigned long next; | |
d7ecbddf MS |
164 | pmdval_t prot_sect; |
165 | pgprot_t prot_pte; | |
166 | ||
167 | if (map_io) { | |
cc07aabc | 168 | prot_sect = PROT_SECT_DEVICE_nGnRE; |
d7ecbddf MS |
169 | prot_pte = __pgprot(PROT_DEVICE_nGnRE); |
170 | } else { | |
cc07aabc | 171 | prot_sect = PROT_SECT_NORMAL_EXEC; |
d7ecbddf MS |
172 | prot_pte = PAGE_KERNEL_EXEC; |
173 | } | |
c1cc1552 CM |
174 | |
175 | /* | |
176 | * Check for initial section mappings in the pgd/pud and remove them. | |
177 | */ | |
178 | if (pud_none(*pud) || pud_bad(*pud)) { | |
179 | pmd = early_alloc(PTRS_PER_PMD * sizeof(pmd_t)); | |
180 | pud_populate(&init_mm, pud, pmd); | |
181 | } | |
182 | ||
183 | pmd = pmd_offset(pud, addr); | |
184 | do { | |
185 | next = pmd_addr_end(addr, end); | |
186 | /* try section mapping first */ | |
a55f9929 CM |
187 | if (((addr | next | phys) & ~SECTION_MASK) == 0) { |
188 | pmd_t old_pmd =*pmd; | |
d7ecbddf | 189 | set_pmd(pmd, __pmd(phys | prot_sect)); |
a55f9929 CM |
190 | /* |
191 | * Check for previous table entries created during | |
192 | * boot (__create_page_tables) and flush them. | |
193 | */ | |
194 | if (!pmd_none(old_pmd)) | |
195 | flush_tlb_all(); | |
196 | } else { | |
d7ecbddf MS |
197 | alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys), |
198 | prot_pte); | |
a55f9929 | 199 | } |
c1cc1552 CM |
200 | phys += next - addr; |
201 | } while (pmd++, addr = next, addr != end); | |
202 | } | |
203 | ||
204 | static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr, | |
d7ecbddf MS |
205 | unsigned long end, unsigned long phys, |
206 | int map_io) | |
c1cc1552 | 207 | { |
c79b954b | 208 | pud_t *pud; |
c1cc1552 CM |
209 | unsigned long next; |
210 | ||
c79b954b JL |
211 | if (pgd_none(*pgd)) { |
212 | pud = early_alloc(PTRS_PER_PUD * sizeof(pud_t)); | |
213 | pgd_populate(&init_mm, pgd, pud); | |
214 | } | |
215 | BUG_ON(pgd_bad(*pgd)); | |
216 | ||
217 | pud = pud_offset(pgd, addr); | |
c1cc1552 CM |
218 | do { |
219 | next = pud_addr_end(addr, end); | |
206a2a73 SC |
220 | |
221 | /* | |
222 | * For 4K granule only, attempt to put down a 1GB block | |
223 | */ | |
cc07aabc | 224 | if (!map_io && (PAGE_SHIFT == 12) && |
206a2a73 SC |
225 | ((addr | next | phys) & ~PUD_MASK) == 0) { |
226 | pud_t old_pud = *pud; | |
227 | set_pud(pud, __pud(phys | PROT_SECT_NORMAL_EXEC)); | |
228 | ||
229 | /* | |
230 | * If we have an old value for a pud, it will | |
231 | * be pointing to a pmd table that we no longer | |
232 | * need (from swapper_pg_dir). | |
233 | * | |
234 | * Look up the old pmd table and free it. | |
235 | */ | |
236 | if (!pud_none(old_pud)) { | |
237 | phys_addr_t table = __pa(pmd_offset(&old_pud, 0)); | |
238 | memblock_free(table, PAGE_SIZE); | |
239 | flush_tlb_all(); | |
240 | } | |
241 | } else { | |
cc07aabc | 242 | alloc_init_pmd(pud, addr, next, phys, map_io); |
206a2a73 | 243 | } |
c1cc1552 CM |
244 | phys += next - addr; |
245 | } while (pud++, addr = next, addr != end); | |
246 | } | |
247 | ||
248 | /* | |
249 | * Create the page directory entries and any necessary page tables for the | |
250 | * mapping specified by 'md'. | |
251 | */ | |
d7ecbddf MS |
252 | static void __init __create_mapping(pgd_t *pgd, phys_addr_t phys, |
253 | unsigned long virt, phys_addr_t size, | |
254 | int map_io) | |
c1cc1552 CM |
255 | { |
256 | unsigned long addr, length, end, next; | |
c1cc1552 CM |
257 | |
258 | addr = virt & PAGE_MASK; | |
259 | length = PAGE_ALIGN(size + (virt & ~PAGE_MASK)); | |
260 | ||
c1cc1552 CM |
261 | end = addr + length; |
262 | do { | |
263 | next = pgd_addr_end(addr, end); | |
d7ecbddf | 264 | alloc_init_pud(pgd, addr, next, phys, map_io); |
c1cc1552 CM |
265 | phys += next - addr; |
266 | } while (pgd++, addr = next, addr != end); | |
267 | } | |
268 | ||
d7ecbddf MS |
269 | static void __init create_mapping(phys_addr_t phys, unsigned long virt, |
270 | phys_addr_t size) | |
271 | { | |
272 | if (virt < VMALLOC_START) { | |
273 | pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n", | |
274 | &phys, virt); | |
275 | return; | |
276 | } | |
277 | __create_mapping(pgd_offset_k(virt & PAGE_MASK), phys, virt, size, 0); | |
278 | } | |
279 | ||
280 | void __init create_id_mapping(phys_addr_t addr, phys_addr_t size, int map_io) | |
281 | { | |
282 | if ((addr >> PGDIR_SHIFT) >= ARRAY_SIZE(idmap_pg_dir)) { | |
283 | pr_warn("BUG: not creating id mapping for %pa\n", &addr); | |
284 | return; | |
285 | } | |
286 | __create_mapping(&idmap_pg_dir[pgd_index(addr)], | |
287 | addr, addr, size, map_io); | |
288 | } | |
289 | ||
c1cc1552 CM |
290 | static void __init map_mem(void) |
291 | { | |
292 | struct memblock_region *reg; | |
e25208f7 | 293 | phys_addr_t limit; |
c1cc1552 | 294 | |
f6bc87c3 SC |
295 | /* |
296 | * Temporarily limit the memblock range. We need to do this as | |
297 | * create_mapping requires puds, pmds and ptes to be allocated from | |
298 | * memory addressable from the initial direct kernel mapping. | |
299 | * | |
300 | * The initial direct kernel mapping, located at swapper_pg_dir, | |
c79b954b | 301 | * gives us PUD_SIZE memory starting from PHYS_OFFSET (which must be |
e25208f7 | 302 | * aligned to 2MB as per Documentation/arm64/booting.txt). |
f6bc87c3 | 303 | */ |
c79b954b | 304 | limit = PHYS_OFFSET + PUD_SIZE; |
e25208f7 | 305 | memblock_set_current_limit(limit); |
f6bc87c3 | 306 | |
c1cc1552 CM |
307 | /* map all the memory banks */ |
308 | for_each_memblock(memory, reg) { | |
309 | phys_addr_t start = reg->base; | |
310 | phys_addr_t end = start + reg->size; | |
311 | ||
312 | if (start >= end) | |
313 | break; | |
314 | ||
e25208f7 CM |
315 | #ifndef CONFIG_ARM64_64K_PAGES |
316 | /* | |
317 | * For the first memory bank align the start address and | |
318 | * current memblock limit to prevent create_mapping() from | |
319 | * allocating pte page tables from unmapped memory. | |
320 | * When 64K pages are enabled, the pte page table for the | |
321 | * first PGDIR_SIZE is already present in swapper_pg_dir. | |
322 | */ | |
323 | if (start < limit) | |
324 | start = ALIGN(start, PMD_SIZE); | |
325 | if (end < limit) { | |
326 | limit = end & PMD_MASK; | |
327 | memblock_set_current_limit(limit); | |
328 | } | |
329 | #endif | |
330 | ||
c1cc1552 CM |
331 | create_mapping(start, __phys_to_virt(start), end - start); |
332 | } | |
f6bc87c3 SC |
333 | |
334 | /* Limit no longer required. */ | |
335 | memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE); | |
c1cc1552 CM |
336 | } |
337 | ||
338 | /* | |
339 | * paging_init() sets up the page tables, initialises the zone memory | |
340 | * maps and sets up the zero page. | |
341 | */ | |
342 | void __init paging_init(void) | |
343 | { | |
344 | void *zero_page; | |
345 | ||
c1cc1552 CM |
346 | map_mem(); |
347 | ||
348 | /* | |
349 | * Finally flush the caches and tlb to ensure that we're in a | |
350 | * consistent state. | |
351 | */ | |
352 | flush_cache_all(); | |
353 | flush_tlb_all(); | |
354 | ||
355 | /* allocate the zero page. */ | |
356 | zero_page = early_alloc(PAGE_SIZE); | |
357 | ||
358 | bootmem_init(); | |
359 | ||
360 | empty_zero_page = virt_to_page(zero_page); | |
c1cc1552 CM |
361 | |
362 | /* | |
363 | * TTBR0 is only used for the identity mapping at this stage. Make it | |
364 | * point to zero page to avoid speculatively fetching new entries. | |
365 | */ | |
366 | cpu_set_reserved_ttbr0(); | |
367 | flush_tlb_all(); | |
368 | } | |
369 | ||
370 | /* | |
371 | * Enable the identity mapping to allow the MMU disabling. | |
372 | */ | |
373 | void setup_mm_for_reboot(void) | |
374 | { | |
375 | cpu_switch_mm(idmap_pg_dir, &init_mm); | |
376 | flush_tlb_all(); | |
377 | } | |
378 | ||
379 | /* | |
380 | * Check whether a kernel address is valid (derived from arch/x86/). | |
381 | */ | |
382 | int kern_addr_valid(unsigned long addr) | |
383 | { | |
384 | pgd_t *pgd; | |
385 | pud_t *pud; | |
386 | pmd_t *pmd; | |
387 | pte_t *pte; | |
388 | ||
389 | if ((((long)addr) >> VA_BITS) != -1UL) | |
390 | return 0; | |
391 | ||
392 | pgd = pgd_offset_k(addr); | |
393 | if (pgd_none(*pgd)) | |
394 | return 0; | |
395 | ||
396 | pud = pud_offset(pgd, addr); | |
397 | if (pud_none(*pud)) | |
398 | return 0; | |
399 | ||
206a2a73 SC |
400 | if (pud_sect(*pud)) |
401 | return pfn_valid(pud_pfn(*pud)); | |
402 | ||
c1cc1552 CM |
403 | pmd = pmd_offset(pud, addr); |
404 | if (pmd_none(*pmd)) | |
405 | return 0; | |
406 | ||
da6e4cb6 DA |
407 | if (pmd_sect(*pmd)) |
408 | return pfn_valid(pmd_pfn(*pmd)); | |
409 | ||
c1cc1552 CM |
410 | pte = pte_offset_kernel(pmd, addr); |
411 | if (pte_none(*pte)) | |
412 | return 0; | |
413 | ||
414 | return pfn_valid(pte_pfn(*pte)); | |
415 | } | |
416 | #ifdef CONFIG_SPARSEMEM_VMEMMAP | |
417 | #ifdef CONFIG_ARM64_64K_PAGES | |
0aad818b | 418 | int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) |
c1cc1552 | 419 | { |
0aad818b | 420 | return vmemmap_populate_basepages(start, end, node); |
c1cc1552 CM |
421 | } |
422 | #else /* !CONFIG_ARM64_64K_PAGES */ | |
0aad818b | 423 | int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) |
c1cc1552 | 424 | { |
0aad818b | 425 | unsigned long addr = start; |
c1cc1552 CM |
426 | unsigned long next; |
427 | pgd_t *pgd; | |
428 | pud_t *pud; | |
429 | pmd_t *pmd; | |
430 | ||
431 | do { | |
432 | next = pmd_addr_end(addr, end); | |
433 | ||
434 | pgd = vmemmap_pgd_populate(addr, node); | |
435 | if (!pgd) | |
436 | return -ENOMEM; | |
437 | ||
438 | pud = vmemmap_pud_populate(pgd, addr, node); | |
439 | if (!pud) | |
440 | return -ENOMEM; | |
441 | ||
442 | pmd = pmd_offset(pud, addr); | |
443 | if (pmd_none(*pmd)) { | |
444 | void *p = NULL; | |
445 | ||
446 | p = vmemmap_alloc_block_buf(PMD_SIZE, node); | |
447 | if (!p) | |
448 | return -ENOMEM; | |
449 | ||
a501e324 | 450 | set_pmd(pmd, __pmd(__pa(p) | PROT_SECT_NORMAL)); |
c1cc1552 CM |
451 | } else |
452 | vmemmap_verify((pte_t *)pmd, node, addr, next); | |
453 | } while (addr = next, addr != end); | |
454 | ||
455 | return 0; | |
456 | } | |
457 | #endif /* CONFIG_ARM64_64K_PAGES */ | |
0aad818b | 458 | void vmemmap_free(unsigned long start, unsigned long end) |
0197518c TC |
459 | { |
460 | } | |
c1cc1552 | 461 | #endif /* CONFIG_SPARSEMEM_VMEMMAP */ |