xref: /openbmc/linux/arch/arm/mm/mmu.c (revision 39b6f3aa)
1 /*
2  *  linux/arch/arm/mm/mmu.c
3  *
4  *  Copyright (C) 1995-2005 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/init.h>
14 #include <linux/mman.h>
15 #include <linux/nodemask.h>
16 #include <linux/memblock.h>
17 #include <linux/fs.h>
18 #include <linux/vmalloc.h>
19 #include <linux/sizes.h>
20 
21 #include <asm/cp15.h>
22 #include <asm/cputype.h>
23 #include <asm/sections.h>
24 #include <asm/cachetype.h>
25 #include <asm/setup.h>
26 #include <asm/smp_plat.h>
27 #include <asm/tlb.h>
28 #include <asm/highmem.h>
29 #include <asm/system_info.h>
30 #include <asm/traps.h>
31 
32 #include <asm/mach/arch.h>
33 #include <asm/mach/map.h>
34 #include <asm/mach/pci.h>
35 
36 #include "mm.h"
37 #include "tcm.h"
38 
39 /*
40  * empty_zero_page is a special page that is used for
41  * zero-initialized data and COW.
42  */
43 struct page *empty_zero_page;
44 EXPORT_SYMBOL(empty_zero_page);
45 
46 /*
47  * The pmd table for the upper-most set of pages.
48  */
49 pmd_t *top_pmd;
50 
51 #define CPOLICY_UNCACHED	0
52 #define CPOLICY_BUFFERED	1
53 #define CPOLICY_WRITETHROUGH	2
54 #define CPOLICY_WRITEBACK	3
55 #define CPOLICY_WRITEALLOC	4
56 
57 static unsigned int cachepolicy __initdata = CPOLICY_WRITEBACK;
58 static unsigned int ecc_mask __initdata = 0;
59 pgprot_t pgprot_user;
60 pgprot_t pgprot_kernel;
61 pgprot_t pgprot_hyp_device;
62 pgprot_t pgprot_s2;
63 pgprot_t pgprot_s2_device;
64 
65 EXPORT_SYMBOL(pgprot_user);
66 EXPORT_SYMBOL(pgprot_kernel);
67 
68 struct cachepolicy {
69 	const char	policy[16];
70 	unsigned int	cr_mask;
71 	pmdval_t	pmd;
72 	pteval_t	pte;
73 	pteval_t	pte_s2;
74 };
75 
76 #ifdef CONFIG_ARM_LPAE
77 #define s2_policy(policy)	policy
78 #else
79 #define s2_policy(policy)	0
80 #endif
81 
82 static struct cachepolicy cache_policies[] __initdata = {
83 	{
84 		.policy		= "uncached",
85 		.cr_mask	= CR_W|CR_C,
86 		.pmd		= PMD_SECT_UNCACHED,
87 		.pte		= L_PTE_MT_UNCACHED,
88 		.pte_s2		= s2_policy(L_PTE_S2_MT_UNCACHED),
89 	}, {
90 		.policy		= "buffered",
91 		.cr_mask	= CR_C,
92 		.pmd		= PMD_SECT_BUFFERED,
93 		.pte		= L_PTE_MT_BUFFERABLE,
94 		.pte_s2		= s2_policy(L_PTE_S2_MT_UNCACHED),
95 	}, {
96 		.policy		= "writethrough",
97 		.cr_mask	= 0,
98 		.pmd		= PMD_SECT_WT,
99 		.pte		= L_PTE_MT_WRITETHROUGH,
100 		.pte_s2		= s2_policy(L_PTE_S2_MT_WRITETHROUGH),
101 	}, {
102 		.policy		= "writeback",
103 		.cr_mask	= 0,
104 		.pmd		= PMD_SECT_WB,
105 		.pte		= L_PTE_MT_WRITEBACK,
106 		.pte_s2		= s2_policy(L_PTE_S2_MT_WRITEBACK),
107 	}, {
108 		.policy		= "writealloc",
109 		.cr_mask	= 0,
110 		.pmd		= PMD_SECT_WBWA,
111 		.pte		= L_PTE_MT_WRITEALLOC,
112 		.pte_s2		= s2_policy(L_PTE_S2_MT_WRITEBACK),
113 	}
114 };
115 
116 #ifdef CONFIG_CPU_CP15
117 /*
118  * These are useful for identifying cache coherency
119  * problems by allowing the cache or the cache and
120  * writebuffer to be turned off.  (Note: the write
121  * buffer should not be on and the cache off).
122  */
123 static int __init early_cachepolicy(char *p)
124 {
125 	int i;
126 
127 	for (i = 0; i < ARRAY_SIZE(cache_policies); i++) {
128 		int len = strlen(cache_policies[i].policy);
129 
130 		if (memcmp(p, cache_policies[i].policy, len) == 0) {
131 			cachepolicy = i;
132 			cr_alignment &= ~cache_policies[i].cr_mask;
133 			cr_no_alignment &= ~cache_policies[i].cr_mask;
134 			break;
135 		}
136 	}
137 	if (i == ARRAY_SIZE(cache_policies))
138 		printk(KERN_ERR "ERROR: unknown or unsupported cache policy\n");
139 	/*
140 	 * This restriction is partly to do with the way we boot; it is
141 	 * unpredictable to have memory mapped using two different sets of
142 	 * memory attributes (shared, type, and cache attribs).  We can not
143 	 * change these attributes once the initial assembly has setup the
144 	 * page tables.
145 	 */
146 	if (cpu_architecture() >= CPU_ARCH_ARMv6) {
147 		printk(KERN_WARNING "Only cachepolicy=writeback supported on ARMv6 and later\n");
148 		cachepolicy = CPOLICY_WRITEBACK;
149 	}
150 	flush_cache_all();
151 	set_cr(cr_alignment);
152 	return 0;
153 }
154 early_param("cachepolicy", early_cachepolicy);
155 
156 static int __init early_nocache(char *__unused)
157 {
158 	char *p = "buffered";
159 	printk(KERN_WARNING "nocache is deprecated; use cachepolicy=%s\n", p);
160 	early_cachepolicy(p);
161 	return 0;
162 }
163 early_param("nocache", early_nocache);
164 
165 static int __init early_nowrite(char *__unused)
166 {
167 	char *p = "uncached";
168 	printk(KERN_WARNING "nowb is deprecated; use cachepolicy=%s\n", p);
169 	early_cachepolicy(p);
170 	return 0;
171 }
172 early_param("nowb", early_nowrite);
173 
174 #ifndef CONFIG_ARM_LPAE
175 static int __init early_ecc(char *p)
176 {
177 	if (memcmp(p, "on", 2) == 0)
178 		ecc_mask = PMD_PROTECTION;
179 	else if (memcmp(p, "off", 3) == 0)
180 		ecc_mask = 0;
181 	return 0;
182 }
183 early_param("ecc", early_ecc);
184 #endif
185 
186 static int __init noalign_setup(char *__unused)
187 {
188 	cr_alignment &= ~CR_A;
189 	cr_no_alignment &= ~CR_A;
190 	set_cr(cr_alignment);
191 	return 1;
192 }
193 __setup("noalign", noalign_setup);
194 
195 #ifndef CONFIG_SMP
196 void adjust_cr(unsigned long mask, unsigned long set)
197 {
198 	unsigned long flags;
199 
200 	mask &= ~CR_A;
201 
202 	set &= mask;
203 
204 	local_irq_save(flags);
205 
206 	cr_no_alignment = (cr_no_alignment & ~mask) | set;
207 	cr_alignment = (cr_alignment & ~mask) | set;
208 
209 	set_cr((get_cr() & ~mask) | set);
210 
211 	local_irq_restore(flags);
212 }
213 #endif
214 
215 #else /* ifdef CONFIG_CPU_CP15 */
216 
217 static int __init early_cachepolicy(char *p)
218 {
219 	pr_warning("cachepolicy kernel parameter not supported without cp15\n");
220 }
221 early_param("cachepolicy", early_cachepolicy);
222 
223 static int __init noalign_setup(char *__unused)
224 {
225 	pr_warning("noalign kernel parameter not supported without cp15\n");
226 }
227 __setup("noalign", noalign_setup);
228 
229 #endif /* ifdef CONFIG_CPU_CP15 / else */
230 
231 #define PROT_PTE_DEVICE		L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN
232 #define PROT_SECT_DEVICE	PMD_TYPE_SECT|PMD_SECT_AP_WRITE
233 
234 static struct mem_type mem_types[] = {
235 	[MT_DEVICE] = {		  /* Strongly ordered / ARMv6 shared device */
236 		.prot_pte	= PROT_PTE_DEVICE | L_PTE_MT_DEV_SHARED |
237 				  L_PTE_SHARED,
238 		.prot_l1	= PMD_TYPE_TABLE,
239 		.prot_sect	= PROT_SECT_DEVICE | PMD_SECT_S,
240 		.domain		= DOMAIN_IO,
241 	},
242 	[MT_DEVICE_NONSHARED] = { /* ARMv6 non-shared device */
243 		.prot_pte	= PROT_PTE_DEVICE | L_PTE_MT_DEV_NONSHARED,
244 		.prot_l1	= PMD_TYPE_TABLE,
245 		.prot_sect	= PROT_SECT_DEVICE,
246 		.domain		= DOMAIN_IO,
247 	},
248 	[MT_DEVICE_CACHED] = {	  /* ioremap_cached */
249 		.prot_pte	= PROT_PTE_DEVICE | L_PTE_MT_DEV_CACHED,
250 		.prot_l1	= PMD_TYPE_TABLE,
251 		.prot_sect	= PROT_SECT_DEVICE | PMD_SECT_WB,
252 		.domain		= DOMAIN_IO,
253 	},
254 	[MT_DEVICE_WC] = {	/* ioremap_wc */
255 		.prot_pte	= PROT_PTE_DEVICE | L_PTE_MT_DEV_WC,
256 		.prot_l1	= PMD_TYPE_TABLE,
257 		.prot_sect	= PROT_SECT_DEVICE,
258 		.domain		= DOMAIN_IO,
259 	},
260 	[MT_UNCACHED] = {
261 		.prot_pte	= PROT_PTE_DEVICE,
262 		.prot_l1	= PMD_TYPE_TABLE,
263 		.prot_sect	= PMD_TYPE_SECT | PMD_SECT_XN,
264 		.domain		= DOMAIN_IO,
265 	},
266 	[MT_CACHECLEAN] = {
267 		.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
268 		.domain    = DOMAIN_KERNEL,
269 	},
270 #ifndef CONFIG_ARM_LPAE
271 	[MT_MINICLEAN] = {
272 		.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_MINICACHE,
273 		.domain    = DOMAIN_KERNEL,
274 	},
275 #endif
276 	[MT_LOW_VECTORS] = {
277 		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
278 				L_PTE_RDONLY,
279 		.prot_l1   = PMD_TYPE_TABLE,
280 		.domain    = DOMAIN_USER,
281 	},
282 	[MT_HIGH_VECTORS] = {
283 		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
284 				L_PTE_USER | L_PTE_RDONLY,
285 		.prot_l1   = PMD_TYPE_TABLE,
286 		.domain    = DOMAIN_USER,
287 	},
288 	[MT_MEMORY] = {
289 		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
290 		.prot_l1   = PMD_TYPE_TABLE,
291 		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
292 		.domain    = DOMAIN_KERNEL,
293 	},
294 	[MT_ROM] = {
295 		.prot_sect = PMD_TYPE_SECT,
296 		.domain    = DOMAIN_KERNEL,
297 	},
298 	[MT_MEMORY_NONCACHED] = {
299 		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
300 				L_PTE_MT_BUFFERABLE,
301 		.prot_l1   = PMD_TYPE_TABLE,
302 		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
303 		.domain    = DOMAIN_KERNEL,
304 	},
305 	[MT_MEMORY_DTCM] = {
306 		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
307 				L_PTE_XN,
308 		.prot_l1   = PMD_TYPE_TABLE,
309 		.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
310 		.domain    = DOMAIN_KERNEL,
311 	},
312 	[MT_MEMORY_ITCM] = {
313 		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
314 		.prot_l1   = PMD_TYPE_TABLE,
315 		.domain    = DOMAIN_KERNEL,
316 	},
317 	[MT_MEMORY_SO] = {
318 		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
319 				L_PTE_MT_UNCACHED | L_PTE_XN,
320 		.prot_l1   = PMD_TYPE_TABLE,
321 		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_S |
322 				PMD_SECT_UNCACHED | PMD_SECT_XN,
323 		.domain    = DOMAIN_KERNEL,
324 	},
325 	[MT_MEMORY_DMA_READY] = {
326 		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
327 		.prot_l1   = PMD_TYPE_TABLE,
328 		.domain    = DOMAIN_KERNEL,
329 	},
330 };
331 
332 const struct mem_type *get_mem_type(unsigned int type)
333 {
334 	return type < ARRAY_SIZE(mem_types) ? &mem_types[type] : NULL;
335 }
336 EXPORT_SYMBOL(get_mem_type);
337 
338 /*
339  * Adjust the PMD section entries according to the CPU in use.
340  */
341 static void __init build_mem_type_table(void)
342 {
343 	struct cachepolicy *cp;
344 	unsigned int cr = get_cr();
345 	pteval_t user_pgprot, kern_pgprot, vecs_pgprot;
346 	pteval_t hyp_device_pgprot, s2_pgprot, s2_device_pgprot;
347 	int cpu_arch = cpu_architecture();
348 	int i;
349 
350 	if (cpu_arch < CPU_ARCH_ARMv6) {
351 #if defined(CONFIG_CPU_DCACHE_DISABLE)
352 		if (cachepolicy > CPOLICY_BUFFERED)
353 			cachepolicy = CPOLICY_BUFFERED;
354 #elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH)
355 		if (cachepolicy > CPOLICY_WRITETHROUGH)
356 			cachepolicy = CPOLICY_WRITETHROUGH;
357 #endif
358 	}
359 	if (cpu_arch < CPU_ARCH_ARMv5) {
360 		if (cachepolicy >= CPOLICY_WRITEALLOC)
361 			cachepolicy = CPOLICY_WRITEBACK;
362 		ecc_mask = 0;
363 	}
364 	if (is_smp())
365 		cachepolicy = CPOLICY_WRITEALLOC;
366 
367 	/*
368 	 * Strip out features not present on earlier architectures.
369 	 * Pre-ARMv5 CPUs don't have TEX bits.  Pre-ARMv6 CPUs or those
370 	 * without extended page tables don't have the 'Shared' bit.
371 	 */
372 	if (cpu_arch < CPU_ARCH_ARMv5)
373 		for (i = 0; i < ARRAY_SIZE(mem_types); i++)
374 			mem_types[i].prot_sect &= ~PMD_SECT_TEX(7);
375 	if ((cpu_arch < CPU_ARCH_ARMv6 || !(cr & CR_XP)) && !cpu_is_xsc3())
376 		for (i = 0; i < ARRAY_SIZE(mem_types); i++)
377 			mem_types[i].prot_sect &= ~PMD_SECT_S;
378 
379 	/*
380 	 * ARMv5 and lower, bit 4 must be set for page tables (was: cache
381 	 * "update-able on write" bit on ARM610).  However, Xscale and
382 	 * Xscale3 require this bit to be cleared.
383 	 */
384 	if (cpu_is_xscale() || cpu_is_xsc3()) {
385 		for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
386 			mem_types[i].prot_sect &= ~PMD_BIT4;
387 			mem_types[i].prot_l1 &= ~PMD_BIT4;
388 		}
389 	} else if (cpu_arch < CPU_ARCH_ARMv6) {
390 		for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
391 			if (mem_types[i].prot_l1)
392 				mem_types[i].prot_l1 |= PMD_BIT4;
393 			if (mem_types[i].prot_sect)
394 				mem_types[i].prot_sect |= PMD_BIT4;
395 		}
396 	}
397 
398 	/*
399 	 * Mark the device areas according to the CPU/architecture.
400 	 */
401 	if (cpu_is_xsc3() || (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP))) {
402 		if (!cpu_is_xsc3()) {
403 			/*
404 			 * Mark device regions on ARMv6+ as execute-never
405 			 * to prevent speculative instruction fetches.
406 			 */
407 			mem_types[MT_DEVICE].prot_sect |= PMD_SECT_XN;
408 			mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_XN;
409 			mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_XN;
410 			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_XN;
411 		}
412 		if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) {
413 			/*
414 			 * For ARMv7 with TEX remapping,
415 			 * - shared device is SXCB=1100
416 			 * - nonshared device is SXCB=0100
417 			 * - write combine device mem is SXCB=0001
418 			 * (Uncached Normal memory)
419 			 */
420 			mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1);
421 			mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(1);
422 			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
423 		} else if (cpu_is_xsc3()) {
424 			/*
425 			 * For Xscale3,
426 			 * - shared device is TEXCB=00101
427 			 * - nonshared device is TEXCB=01000
428 			 * - write combine device mem is TEXCB=00100
429 			 * (Inner/Outer Uncacheable in xsc3 parlance)
430 			 */
431 			mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1) | PMD_SECT_BUFFERED;
432 			mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2);
433 			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
434 		} else {
435 			/*
436 			 * For ARMv6 and ARMv7 without TEX remapping,
437 			 * - shared device is TEXCB=00001
438 			 * - nonshared device is TEXCB=01000
439 			 * - write combine device mem is TEXCB=00100
440 			 * (Uncached Normal in ARMv6 parlance).
441 			 */
442 			mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED;
443 			mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2);
444 			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
445 		}
446 	} else {
447 		/*
448 		 * On others, write combining is "Uncached/Buffered"
449 		 */
450 		mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
451 	}
452 
453 	/*
454 	 * Now deal with the memory-type mappings
455 	 */
456 	cp = &cache_policies[cachepolicy];
457 	vecs_pgprot = kern_pgprot = user_pgprot = cp->pte;
458 	s2_pgprot = cp->pte_s2;
459 	hyp_device_pgprot = s2_device_pgprot = mem_types[MT_DEVICE].prot_pte;
460 
461 	/*
462 	 * ARMv6 and above have extended page tables.
463 	 */
464 	if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) {
465 #ifndef CONFIG_ARM_LPAE
466 		/*
467 		 * Mark cache clean areas and XIP ROM read only
468 		 * from SVC mode and no access from userspace.
469 		 */
470 		mem_types[MT_ROM].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
471 		mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
472 		mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
473 #endif
474 
475 		if (is_smp()) {
476 			/*
477 			 * Mark memory with the "shared" attribute
478 			 * for SMP systems
479 			 */
480 			user_pgprot |= L_PTE_SHARED;
481 			kern_pgprot |= L_PTE_SHARED;
482 			vecs_pgprot |= L_PTE_SHARED;
483 			s2_pgprot |= L_PTE_SHARED;
484 			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_S;
485 			mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_SHARED;
486 			mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_S;
487 			mem_types[MT_DEVICE_CACHED].prot_pte |= L_PTE_SHARED;
488 			mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
489 			mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED;
490 			mem_types[MT_MEMORY_DMA_READY].prot_pte |= L_PTE_SHARED;
491 			mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S;
492 			mem_types[MT_MEMORY_NONCACHED].prot_pte |= L_PTE_SHARED;
493 		}
494 	}
495 
496 	/*
497 	 * Non-cacheable Normal - intended for memory areas that must
498 	 * not cause dirty cache line writebacks when used
499 	 */
500 	if (cpu_arch >= CPU_ARCH_ARMv6) {
501 		if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) {
502 			/* Non-cacheable Normal is XCB = 001 */
503 			mem_types[MT_MEMORY_NONCACHED].prot_sect |=
504 				PMD_SECT_BUFFERED;
505 		} else {
506 			/* For both ARMv6 and non-TEX-remapping ARMv7 */
507 			mem_types[MT_MEMORY_NONCACHED].prot_sect |=
508 				PMD_SECT_TEX(1);
509 		}
510 	} else {
511 		mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_BUFFERABLE;
512 	}
513 
514 #ifdef CONFIG_ARM_LPAE
515 	/*
516 	 * Do not generate access flag faults for the kernel mappings.
517 	 */
518 	for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
519 		mem_types[i].prot_pte |= PTE_EXT_AF;
520 		if (mem_types[i].prot_sect)
521 			mem_types[i].prot_sect |= PMD_SECT_AF;
522 	}
523 	kern_pgprot |= PTE_EXT_AF;
524 	vecs_pgprot |= PTE_EXT_AF;
525 #endif
526 
527 	for (i = 0; i < 16; i++) {
528 		pteval_t v = pgprot_val(protection_map[i]);
529 		protection_map[i] = __pgprot(v | user_pgprot);
530 	}
531 
532 	mem_types[MT_LOW_VECTORS].prot_pte |= vecs_pgprot;
533 	mem_types[MT_HIGH_VECTORS].prot_pte |= vecs_pgprot;
534 
535 	pgprot_user   = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | user_pgprot);
536 	pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
537 				 L_PTE_DIRTY | kern_pgprot);
538 	pgprot_s2  = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | s2_pgprot);
539 	pgprot_s2_device  = __pgprot(s2_device_pgprot);
540 	pgprot_hyp_device  = __pgprot(hyp_device_pgprot);
541 
542 	mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
543 	mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;
544 	mem_types[MT_MEMORY].prot_sect |= ecc_mask | cp->pmd;
545 	mem_types[MT_MEMORY].prot_pte |= kern_pgprot;
546 	mem_types[MT_MEMORY_DMA_READY].prot_pte |= kern_pgprot;
547 	mem_types[MT_MEMORY_NONCACHED].prot_sect |= ecc_mask;
548 	mem_types[MT_ROM].prot_sect |= cp->pmd;
549 
550 	switch (cp->pmd) {
551 	case PMD_SECT_WT:
552 		mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WT;
553 		break;
554 	case PMD_SECT_WB:
555 	case PMD_SECT_WBWA:
556 		mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WB;
557 		break;
558 	}
559 	printk("Memory policy: ECC %sabled, Data cache %s\n",
560 		ecc_mask ? "en" : "dis", cp->policy);
561 
562 	for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
563 		struct mem_type *t = &mem_types[i];
564 		if (t->prot_l1)
565 			t->prot_l1 |= PMD_DOMAIN(t->domain);
566 		if (t->prot_sect)
567 			t->prot_sect |= PMD_DOMAIN(t->domain);
568 	}
569 }
570 
571 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
572 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
573 			      unsigned long size, pgprot_t vma_prot)
574 {
575 	if (!pfn_valid(pfn))
576 		return pgprot_noncached(vma_prot);
577 	else if (file->f_flags & O_SYNC)
578 		return pgprot_writecombine(vma_prot);
579 	return vma_prot;
580 }
581 EXPORT_SYMBOL(phys_mem_access_prot);
582 #endif
583 
584 #define vectors_base()	(vectors_high() ? 0xffff0000 : 0)
585 
586 static void __init *early_alloc_aligned(unsigned long sz, unsigned long align)
587 {
588 	void *ptr = __va(memblock_alloc(sz, align));
589 	memset(ptr, 0, sz);
590 	return ptr;
591 }
592 
593 static void __init *early_alloc(unsigned long sz)
594 {
595 	return early_alloc_aligned(sz, sz);
596 }
597 
598 static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr, unsigned long prot)
599 {
600 	if (pmd_none(*pmd)) {
601 		pte_t *pte = early_alloc(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE);
602 		__pmd_populate(pmd, __pa(pte), prot);
603 	}
604 	BUG_ON(pmd_bad(*pmd));
605 	return pte_offset_kernel(pmd, addr);
606 }
607 
608 static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr,
609 				  unsigned long end, unsigned long pfn,
610 				  const struct mem_type *type)
611 {
612 	pte_t *pte = early_pte_alloc(pmd, addr, type->prot_l1);
613 	do {
614 		set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)), 0);
615 		pfn++;
616 	} while (pte++, addr += PAGE_SIZE, addr != end);
617 }
618 
619 static void __init map_init_section(pmd_t *pmd, unsigned long addr,
620 			unsigned long end, phys_addr_t phys,
621 			const struct mem_type *type)
622 {
623 #ifndef CONFIG_ARM_LPAE
624 	/*
625 	 * In classic MMU format, puds and pmds are folded in to
626 	 * the pgds. pmd_offset gives the PGD entry. PGDs refer to a
627 	 * group of L1 entries making up one logical pointer to
628 	 * an L2 table (2MB), where as PMDs refer to the individual
629 	 * L1 entries (1MB). Hence increment to get the correct
630 	 * offset for odd 1MB sections.
631 	 * (See arch/arm/include/asm/pgtable-2level.h)
632 	 */
633 	if (addr & SECTION_SIZE)
634 		pmd++;
635 #endif
636 	do {
637 		*pmd = __pmd(phys | type->prot_sect);
638 		phys += SECTION_SIZE;
639 	} while (pmd++, addr += SECTION_SIZE, addr != end);
640 
641 	flush_pmd_entry(pmd);
642 }
643 
644 static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
645 				      unsigned long end, phys_addr_t phys,
646 				      const struct mem_type *type)
647 {
648 	pmd_t *pmd = pmd_offset(pud, addr);
649 	unsigned long next;
650 
651 	do {
652 		/*
653 		 * With LPAE, we must loop over to map
654 		 * all the pmds for the given range.
655 		 */
656 		next = pmd_addr_end(addr, end);
657 
658 		/*
659 		 * Try a section mapping - addr, next and phys must all be
660 		 * aligned to a section boundary.
661 		 */
662 		if (type->prot_sect &&
663 				((addr | next | phys) & ~SECTION_MASK) == 0) {
664 			map_init_section(pmd, addr, next, phys, type);
665 		} else {
666 			alloc_init_pte(pmd, addr, next,
667 						__phys_to_pfn(phys), type);
668 		}
669 
670 		phys += next - addr;
671 
672 	} while (pmd++, addr = next, addr != end);
673 }
674 
675 static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
676 	unsigned long end, unsigned long phys, const struct mem_type *type)
677 {
678 	pud_t *pud = pud_offset(pgd, addr);
679 	unsigned long next;
680 
681 	do {
682 		next = pud_addr_end(addr, end);
683 		alloc_init_pmd(pud, addr, next, phys, type);
684 		phys += next - addr;
685 	} while (pud++, addr = next, addr != end);
686 }
687 
688 #ifndef CONFIG_ARM_LPAE
689 static void __init create_36bit_mapping(struct map_desc *md,
690 					const struct mem_type *type)
691 {
692 	unsigned long addr, length, end;
693 	phys_addr_t phys;
694 	pgd_t *pgd;
695 
696 	addr = md->virtual;
697 	phys = __pfn_to_phys(md->pfn);
698 	length = PAGE_ALIGN(md->length);
699 
700 	if (!(cpu_architecture() >= CPU_ARCH_ARMv6 || cpu_is_xsc3())) {
701 		printk(KERN_ERR "MM: CPU does not support supersection "
702 		       "mapping for 0x%08llx at 0x%08lx\n",
703 		       (long long)__pfn_to_phys((u64)md->pfn), addr);
704 		return;
705 	}
706 
707 	/* N.B.	ARMv6 supersections are only defined to work with domain 0.
708 	 *	Since domain assignments can in fact be arbitrary, the
709 	 *	'domain == 0' check below is required to insure that ARMv6
710 	 *	supersections are only allocated for domain 0 regardless
711 	 *	of the actual domain assignments in use.
712 	 */
713 	if (type->domain) {
714 		printk(KERN_ERR "MM: invalid domain in supersection "
715 		       "mapping for 0x%08llx at 0x%08lx\n",
716 		       (long long)__pfn_to_phys((u64)md->pfn), addr);
717 		return;
718 	}
719 
720 	if ((addr | length | __pfn_to_phys(md->pfn)) & ~SUPERSECTION_MASK) {
721 		printk(KERN_ERR "MM: cannot create mapping for 0x%08llx"
722 		       " at 0x%08lx invalid alignment\n",
723 		       (long long)__pfn_to_phys((u64)md->pfn), addr);
724 		return;
725 	}
726 
727 	/*
728 	 * Shift bits [35:32] of address into bits [23:20] of PMD
729 	 * (See ARMv6 spec).
730 	 */
731 	phys |= (((md->pfn >> (32 - PAGE_SHIFT)) & 0xF) << 20);
732 
733 	pgd = pgd_offset_k(addr);
734 	end = addr + length;
735 	do {
736 		pud_t *pud = pud_offset(pgd, addr);
737 		pmd_t *pmd = pmd_offset(pud, addr);
738 		int i;
739 
740 		for (i = 0; i < 16; i++)
741 			*pmd++ = __pmd(phys | type->prot_sect | PMD_SECT_SUPER);
742 
743 		addr += SUPERSECTION_SIZE;
744 		phys += SUPERSECTION_SIZE;
745 		pgd += SUPERSECTION_SIZE >> PGDIR_SHIFT;
746 	} while (addr != end);
747 }
748 #endif	/* !CONFIG_ARM_LPAE */
749 
750 /*
751  * Create the page directory entries and any necessary
752  * page tables for the mapping specified by `md'.  We
753  * are able to cope here with varying sizes and address
754  * offsets, and we take full advantage of sections and
755  * supersections.
756  */
757 static void __init create_mapping(struct map_desc *md)
758 {
759 	unsigned long addr, length, end;
760 	phys_addr_t phys;
761 	const struct mem_type *type;
762 	pgd_t *pgd;
763 
764 	if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) {
765 		printk(KERN_WARNING "BUG: not creating mapping for 0x%08llx"
766 		       " at 0x%08lx in user region\n",
767 		       (long long)__pfn_to_phys((u64)md->pfn), md->virtual);
768 		return;
769 	}
770 
771 	if ((md->type == MT_DEVICE || md->type == MT_ROM) &&
772 	    md->virtual >= PAGE_OFFSET &&
773 	    (md->virtual < VMALLOC_START || md->virtual >= VMALLOC_END)) {
774 		printk(KERN_WARNING "BUG: mapping for 0x%08llx"
775 		       " at 0x%08lx out of vmalloc space\n",
776 		       (long long)__pfn_to_phys((u64)md->pfn), md->virtual);
777 	}
778 
779 	type = &mem_types[md->type];
780 
781 #ifndef CONFIG_ARM_LPAE
782 	/*
783 	 * Catch 36-bit addresses
784 	 */
785 	if (md->pfn >= 0x100000) {
786 		create_36bit_mapping(md, type);
787 		return;
788 	}
789 #endif
790 
791 	addr = md->virtual & PAGE_MASK;
792 	phys = __pfn_to_phys(md->pfn);
793 	length = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
794 
795 	if (type->prot_l1 == 0 && ((addr | phys | length) & ~SECTION_MASK)) {
796 		printk(KERN_WARNING "BUG: map for 0x%08llx at 0x%08lx can not "
797 		       "be mapped using pages, ignoring.\n",
798 		       (long long)__pfn_to_phys(md->pfn), addr);
799 		return;
800 	}
801 
802 	pgd = pgd_offset_k(addr);
803 	end = addr + length;
804 	do {
805 		unsigned long next = pgd_addr_end(addr, end);
806 
807 		alloc_init_pud(pgd, addr, next, phys, type);
808 
809 		phys += next - addr;
810 		addr = next;
811 	} while (pgd++, addr != end);
812 }
813 
814 /*
815  * Create the architecture specific mappings
816  */
817 void __init iotable_init(struct map_desc *io_desc, int nr)
818 {
819 	struct map_desc *md;
820 	struct vm_struct *vm;
821 	struct static_vm *svm;
822 
823 	if (!nr)
824 		return;
825 
826 	svm = early_alloc_aligned(sizeof(*svm) * nr, __alignof__(*svm));
827 
828 	for (md = io_desc; nr; md++, nr--) {
829 		create_mapping(md);
830 
831 		vm = &svm->vm;
832 		vm->addr = (void *)(md->virtual & PAGE_MASK);
833 		vm->size = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
834 		vm->phys_addr = __pfn_to_phys(md->pfn);
835 		vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
836 		vm->flags |= VM_ARM_MTYPE(md->type);
837 		vm->caller = iotable_init;
838 		add_static_vm_early(svm++);
839 	}
840 }
841 
842 void __init vm_reserve_area_early(unsigned long addr, unsigned long size,
843 				  void *caller)
844 {
845 	struct vm_struct *vm;
846 	struct static_vm *svm;
847 
848 	svm = early_alloc_aligned(sizeof(*svm), __alignof__(*svm));
849 
850 	vm = &svm->vm;
851 	vm->addr = (void *)addr;
852 	vm->size = size;
853 	vm->flags = VM_IOREMAP | VM_ARM_EMPTY_MAPPING;
854 	vm->caller = caller;
855 	add_static_vm_early(svm);
856 }
857 
858 #ifndef CONFIG_ARM_LPAE
859 
860 /*
861  * The Linux PMD is made of two consecutive section entries covering 2MB
862  * (see definition in include/asm/pgtable-2level.h).  However a call to
863  * create_mapping() may optimize static mappings by using individual
864  * 1MB section mappings.  This leaves the actual PMD potentially half
865  * initialized if the top or bottom section entry isn't used, leaving it
866  * open to problems if a subsequent ioremap() or vmalloc() tries to use
867  * the virtual space left free by that unused section entry.
868  *
869  * Let's avoid the issue by inserting dummy vm entries covering the unused
870  * PMD halves once the static mappings are in place.
871  */
872 
873 static void __init pmd_empty_section_gap(unsigned long addr)
874 {
875 	vm_reserve_area_early(addr, SECTION_SIZE, pmd_empty_section_gap);
876 }
877 
878 static void __init fill_pmd_gaps(void)
879 {
880 	struct static_vm *svm;
881 	struct vm_struct *vm;
882 	unsigned long addr, next = 0;
883 	pmd_t *pmd;
884 
885 	list_for_each_entry(svm, &static_vmlist, list) {
886 		vm = &svm->vm;
887 		addr = (unsigned long)vm->addr;
888 		if (addr < next)
889 			continue;
890 
891 		/*
892 		 * Check if this vm starts on an odd section boundary.
893 		 * If so and the first section entry for this PMD is free
894 		 * then we block the corresponding virtual address.
895 		 */
896 		if ((addr & ~PMD_MASK) == SECTION_SIZE) {
897 			pmd = pmd_off_k(addr);
898 			if (pmd_none(*pmd))
899 				pmd_empty_section_gap(addr & PMD_MASK);
900 		}
901 
902 		/*
903 		 * Then check if this vm ends on an odd section boundary.
904 		 * If so and the second section entry for this PMD is empty
905 		 * then we block the corresponding virtual address.
906 		 */
907 		addr += vm->size;
908 		if ((addr & ~PMD_MASK) == SECTION_SIZE) {
909 			pmd = pmd_off_k(addr) + 1;
910 			if (pmd_none(*pmd))
911 				pmd_empty_section_gap(addr);
912 		}
913 
914 		/* no need to look at any vm entry until we hit the next PMD */
915 		next = (addr + PMD_SIZE - 1) & PMD_MASK;
916 	}
917 }
918 
919 #else
920 #define fill_pmd_gaps() do { } while (0)
921 #endif
922 
923 #if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
924 static void __init pci_reserve_io(void)
925 {
926 	struct static_vm *svm;
927 
928 	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
929 	if (svm)
930 		return;
931 
932 	vm_reserve_area_early(PCI_IO_VIRT_BASE, SZ_2M, pci_reserve_io);
933 }
934 #else
935 #define pci_reserve_io() do { } while (0)
936 #endif
937 
938 #ifdef CONFIG_DEBUG_LL
939 void __init debug_ll_io_init(void)
940 {
941 	struct map_desc map;
942 
943 	debug_ll_addr(&map.pfn, &map.virtual);
944 	if (!map.pfn || !map.virtual)
945 		return;
946 	map.pfn = __phys_to_pfn(map.pfn);
947 	map.virtual &= PAGE_MASK;
948 	map.length = PAGE_SIZE;
949 	map.type = MT_DEVICE;
950 	create_mapping(&map);
951 }
952 #endif
953 
954 static void * __initdata vmalloc_min =
955 	(void *)(VMALLOC_END - (240 << 20) - VMALLOC_OFFSET);
956 
957 /*
958  * vmalloc=size forces the vmalloc area to be exactly 'size'
959  * bytes. This can be used to increase (or decrease) the vmalloc
960  * area - the default is 240m.
961  */
962 static int __init early_vmalloc(char *arg)
963 {
964 	unsigned long vmalloc_reserve = memparse(arg, NULL);
965 
966 	if (vmalloc_reserve < SZ_16M) {
967 		vmalloc_reserve = SZ_16M;
968 		printk(KERN_WARNING
969 			"vmalloc area too small, limiting to %luMB\n",
970 			vmalloc_reserve >> 20);
971 	}
972 
973 	if (vmalloc_reserve > VMALLOC_END - (PAGE_OFFSET + SZ_32M)) {
974 		vmalloc_reserve = VMALLOC_END - (PAGE_OFFSET + SZ_32M);
975 		printk(KERN_WARNING
976 			"vmalloc area is too big, limiting to %luMB\n",
977 			vmalloc_reserve >> 20);
978 	}
979 
980 	vmalloc_min = (void *)(VMALLOC_END - vmalloc_reserve);
981 	return 0;
982 }
983 early_param("vmalloc", early_vmalloc);
984 
985 phys_addr_t arm_lowmem_limit __initdata = 0;
986 
987 void __init sanity_check_meminfo(void)
988 {
989 	int i, j, highmem = 0;
990 
991 	for (i = 0, j = 0; i < meminfo.nr_banks; i++) {
992 		struct membank *bank = &meminfo.bank[j];
993 		*bank = meminfo.bank[i];
994 
995 		if (bank->start > ULONG_MAX)
996 			highmem = 1;
997 
998 #ifdef CONFIG_HIGHMEM
999 		if (__va(bank->start) >= vmalloc_min ||
1000 		    __va(bank->start) < (void *)PAGE_OFFSET)
1001 			highmem = 1;
1002 
1003 		bank->highmem = highmem;
1004 
1005 		/*
1006 		 * Split those memory banks which are partially overlapping
1007 		 * the vmalloc area greatly simplifying things later.
1008 		 */
1009 		if (!highmem && __va(bank->start) < vmalloc_min &&
1010 		    bank->size > vmalloc_min - __va(bank->start)) {
1011 			if (meminfo.nr_banks >= NR_BANKS) {
1012 				printk(KERN_CRIT "NR_BANKS too low, "
1013 						 "ignoring high memory\n");
1014 			} else {
1015 				memmove(bank + 1, bank,
1016 					(meminfo.nr_banks - i) * sizeof(*bank));
1017 				meminfo.nr_banks++;
1018 				i++;
1019 				bank[1].size -= vmalloc_min - __va(bank->start);
1020 				bank[1].start = __pa(vmalloc_min - 1) + 1;
1021 				bank[1].highmem = highmem = 1;
1022 				j++;
1023 			}
1024 			bank->size = vmalloc_min - __va(bank->start);
1025 		}
1026 #else
1027 		bank->highmem = highmem;
1028 
1029 		/*
1030 		 * Highmem banks not allowed with !CONFIG_HIGHMEM.
1031 		 */
1032 		if (highmem) {
1033 			printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx "
1034 			       "(!CONFIG_HIGHMEM).\n",
1035 			       (unsigned long long)bank->start,
1036 			       (unsigned long long)bank->start + bank->size - 1);
1037 			continue;
1038 		}
1039 
1040 		/*
1041 		 * Check whether this memory bank would entirely overlap
1042 		 * the vmalloc area.
1043 		 */
1044 		if (__va(bank->start) >= vmalloc_min ||
1045 		    __va(bank->start) < (void *)PAGE_OFFSET) {
1046 			printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx "
1047 			       "(vmalloc region overlap).\n",
1048 			       (unsigned long long)bank->start,
1049 			       (unsigned long long)bank->start + bank->size - 1);
1050 			continue;
1051 		}
1052 
1053 		/*
1054 		 * Check whether this memory bank would partially overlap
1055 		 * the vmalloc area.
1056 		 */
1057 		if (__va(bank->start + bank->size - 1) >= vmalloc_min ||
1058 		    __va(bank->start + bank->size - 1) <= __va(bank->start)) {
1059 			unsigned long newsize = vmalloc_min - __va(bank->start);
1060 			printk(KERN_NOTICE "Truncating RAM at %.8llx-%.8llx "
1061 			       "to -%.8llx (vmalloc region overlap).\n",
1062 			       (unsigned long long)bank->start,
1063 			       (unsigned long long)bank->start + bank->size - 1,
1064 			       (unsigned long long)bank->start + newsize - 1);
1065 			bank->size = newsize;
1066 		}
1067 #endif
1068 		if (!bank->highmem && bank->start + bank->size > arm_lowmem_limit)
1069 			arm_lowmem_limit = bank->start + bank->size;
1070 
1071 		j++;
1072 	}
1073 #ifdef CONFIG_HIGHMEM
1074 	if (highmem) {
1075 		const char *reason = NULL;
1076 
1077 		if (cache_is_vipt_aliasing()) {
1078 			/*
1079 			 * Interactions between kmap and other mappings
1080 			 * make highmem support with aliasing VIPT caches
1081 			 * rather difficult.
1082 			 */
1083 			reason = "with VIPT aliasing cache";
1084 		}
1085 		if (reason) {
1086 			printk(KERN_CRIT "HIGHMEM is not supported %s, ignoring high memory\n",
1087 				reason);
1088 			while (j > 0 && meminfo.bank[j - 1].highmem)
1089 				j--;
1090 		}
1091 	}
1092 #endif
1093 	meminfo.nr_banks = j;
1094 	high_memory = __va(arm_lowmem_limit - 1) + 1;
1095 	memblock_set_current_limit(arm_lowmem_limit);
1096 }
1097 
1098 static inline void prepare_page_table(void)
1099 {
1100 	unsigned long addr;
1101 	phys_addr_t end;
1102 
1103 	/*
1104 	 * Clear out all the mappings below the kernel image.
1105 	 */
1106 	for (addr = 0; addr < MODULES_VADDR; addr += PMD_SIZE)
1107 		pmd_clear(pmd_off_k(addr));
1108 
1109 #ifdef CONFIG_XIP_KERNEL
1110 	/* The XIP kernel is mapped in the module area -- skip over it */
1111 	addr = ((unsigned long)_etext + PMD_SIZE - 1) & PMD_MASK;
1112 #endif
1113 	for ( ; addr < PAGE_OFFSET; addr += PMD_SIZE)
1114 		pmd_clear(pmd_off_k(addr));
1115 
1116 	/*
1117 	 * Find the end of the first block of lowmem.
1118 	 */
1119 	end = memblock.memory.regions[0].base + memblock.memory.regions[0].size;
1120 	if (end >= arm_lowmem_limit)
1121 		end = arm_lowmem_limit;
1122 
1123 	/*
1124 	 * Clear out all the kernel space mappings, except for the first
1125 	 * memory bank, up to the vmalloc region.
1126 	 */
1127 	for (addr = __phys_to_virt(end);
1128 	     addr < VMALLOC_START; addr += PMD_SIZE)
1129 		pmd_clear(pmd_off_k(addr));
1130 }
1131 
1132 #ifdef CONFIG_ARM_LPAE
1133 /* the first page is reserved for pgd */
1134 #define SWAPPER_PG_DIR_SIZE	(PAGE_SIZE + \
1135 				 PTRS_PER_PGD * PTRS_PER_PMD * sizeof(pmd_t))
1136 #else
1137 #define SWAPPER_PG_DIR_SIZE	(PTRS_PER_PGD * sizeof(pgd_t))
1138 #endif
1139 
1140 /*
1141  * Reserve the special regions of memory
1142  */
1143 void __init arm_mm_memblock_reserve(void)
1144 {
1145 	/*
1146 	 * Reserve the page tables.  These are already in use,
1147 	 * and can only be in node 0.
1148 	 */
1149 	memblock_reserve(__pa(swapper_pg_dir), SWAPPER_PG_DIR_SIZE);
1150 
1151 #ifdef CONFIG_SA1111
1152 	/*
1153 	 * Because of the SA1111 DMA bug, we want to preserve our
1154 	 * precious DMA-able memory...
1155 	 */
1156 	memblock_reserve(PHYS_OFFSET, __pa(swapper_pg_dir) - PHYS_OFFSET);
1157 #endif
1158 }
1159 
1160 /*
1161  * Set up the device mappings.  Since we clear out the page tables for all
1162  * mappings above VMALLOC_START, we will remove any debug device mappings.
1163  * This means you have to be careful how you debug this function, or any
1164  * called function.  This means you can't use any function or debugging
1165  * method which may touch any device, otherwise the kernel _will_ crash.
1166  */
1167 static void __init devicemaps_init(struct machine_desc *mdesc)
1168 {
1169 	struct map_desc map;
1170 	unsigned long addr;
1171 	void *vectors;
1172 
1173 	/*
1174 	 * Allocate the vector page early.
1175 	 */
1176 	vectors = early_alloc(PAGE_SIZE);
1177 
1178 	early_trap_init(vectors);
1179 
1180 	for (addr = VMALLOC_START; addr; addr += PMD_SIZE)
1181 		pmd_clear(pmd_off_k(addr));
1182 
1183 	/*
1184 	 * Map the kernel if it is XIP.
1185 	 * It is always first in the modulearea.
1186 	 */
1187 #ifdef CONFIG_XIP_KERNEL
1188 	map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK);
1189 	map.virtual = MODULES_VADDR;
1190 	map.length = ((unsigned long)_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK;
1191 	map.type = MT_ROM;
1192 	create_mapping(&map);
1193 #endif
1194 
1195 	/*
1196 	 * Map the cache flushing regions.
1197 	 */
1198 #ifdef FLUSH_BASE
1199 	map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS);
1200 	map.virtual = FLUSH_BASE;
1201 	map.length = SZ_1M;
1202 	map.type = MT_CACHECLEAN;
1203 	create_mapping(&map);
1204 #endif
1205 #ifdef FLUSH_BASE_MINICACHE
1206 	map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + SZ_1M);
1207 	map.virtual = FLUSH_BASE_MINICACHE;
1208 	map.length = SZ_1M;
1209 	map.type = MT_MINICLEAN;
1210 	create_mapping(&map);
1211 #endif
1212 
1213 	/*
1214 	 * Create a mapping for the machine vectors at the high-vectors
1215 	 * location (0xffff0000).  If we aren't using high-vectors, also
1216 	 * create a mapping at the low-vectors virtual address.
1217 	 */
1218 	map.pfn = __phys_to_pfn(virt_to_phys(vectors));
1219 	map.virtual = 0xffff0000;
1220 	map.length = PAGE_SIZE;
1221 	map.type = MT_HIGH_VECTORS;
1222 	create_mapping(&map);
1223 
1224 	if (!vectors_high()) {
1225 		map.virtual = 0;
1226 		map.type = MT_LOW_VECTORS;
1227 		create_mapping(&map);
1228 	}
1229 
1230 	/*
1231 	 * Ask the machine support to map in the statically mapped devices.
1232 	 */
1233 	if (mdesc->map_io)
1234 		mdesc->map_io();
1235 	fill_pmd_gaps();
1236 
1237 	/* Reserve fixed i/o space in VMALLOC region */
1238 	pci_reserve_io();
1239 
1240 	/*
1241 	 * Finally flush the caches and tlb to ensure that we're in a
1242 	 * consistent state wrt the writebuffer.  This also ensures that
1243 	 * any write-allocated cache lines in the vector page are written
1244 	 * back.  After this point, we can start to touch devices again.
1245 	 */
1246 	local_flush_tlb_all();
1247 	flush_cache_all();
1248 }
1249 
1250 static void __init kmap_init(void)
1251 {
1252 #ifdef CONFIG_HIGHMEM
1253 	pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE),
1254 		PKMAP_BASE, _PAGE_KERNEL_TABLE);
1255 #endif
1256 }
1257 
1258 static void __init map_lowmem(void)
1259 {
1260 	struct memblock_region *reg;
1261 
1262 	/* Map all the lowmem memory banks. */
1263 	for_each_memblock(memory, reg) {
1264 		phys_addr_t start = reg->base;
1265 		phys_addr_t end = start + reg->size;
1266 		struct map_desc map;
1267 
1268 		if (end > arm_lowmem_limit)
1269 			end = arm_lowmem_limit;
1270 		if (start >= end)
1271 			break;
1272 
1273 		map.pfn = __phys_to_pfn(start);
1274 		map.virtual = __phys_to_virt(start);
1275 		map.length = end - start;
1276 		map.type = MT_MEMORY;
1277 
1278 		create_mapping(&map);
1279 	}
1280 }
1281 
1282 /*
1283  * paging_init() sets up the page tables, initialises the zone memory
1284  * maps, and sets up the zero page, bad page and bad page tables.
1285  */
1286 void __init paging_init(struct machine_desc *mdesc)
1287 {
1288 	void *zero_page;
1289 
1290 	memblock_set_current_limit(arm_lowmem_limit);
1291 
1292 	build_mem_type_table();
1293 	prepare_page_table();
1294 	map_lowmem();
1295 	dma_contiguous_remap();
1296 	devicemaps_init(mdesc);
1297 	kmap_init();
1298 	tcm_init();
1299 
1300 	top_pmd = pmd_off_k(0xffff0000);
1301 
1302 	/* allocate the zero page. */
1303 	zero_page = early_alloc(PAGE_SIZE);
1304 
1305 	bootmem_init();
1306 
1307 	empty_zero_page = virt_to_page(zero_page);
1308 	__flush_dcache_page(NULL, empty_zero_page);
1309 }
1310