2 * linux/arch/arm/mm/mmu.c
4 * Copyright (C) 1995-2005 Russell King
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.
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>
18 #include <linux/vmalloc.h>
19 #include <linux/sizes.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>
28 #include <asm/highmem.h>
29 #include <asm/system_info.h>
30 #include <asm/traps.h>
32 #include <asm/mach/arch.h>
33 #include <asm/mach/map.h>
34 #include <asm/mach/pci.h>
39 * empty_zero_page is a special page that is used for
40 * zero-initialized data and COW.
42 struct page
*empty_zero_page
;
43 EXPORT_SYMBOL(empty_zero_page
);
46 * The pmd table for the upper-most set of pages.
50 #define CPOLICY_UNCACHED 0
51 #define CPOLICY_BUFFERED 1
52 #define CPOLICY_WRITETHROUGH 2
53 #define CPOLICY_WRITEBACK 3
54 #define CPOLICY_WRITEALLOC 4
56 static unsigned int cachepolicy __initdata
= CPOLICY_WRITEBACK
;
57 static unsigned int ecc_mask __initdata
= 0;
59 pgprot_t pgprot_kernel
;
60 pgprot_t pgprot_hyp_device
;
62 pgprot_t pgprot_s2_device
;
64 EXPORT_SYMBOL(pgprot_user
);
65 EXPORT_SYMBOL(pgprot_kernel
);
68 const char policy
[16];
75 #ifdef CONFIG_ARM_LPAE
76 #define s2_policy(policy) policy
78 #define s2_policy(policy) 0
81 static struct cachepolicy cache_policies
[] __initdata
= {
85 .pmd
= PMD_SECT_UNCACHED
,
86 .pte
= L_PTE_MT_UNCACHED
,
87 .pte_s2
= s2_policy(L_PTE_S2_MT_UNCACHED
),
91 .pmd
= PMD_SECT_BUFFERED
,
92 .pte
= L_PTE_MT_BUFFERABLE
,
93 .pte_s2
= s2_policy(L_PTE_S2_MT_UNCACHED
),
95 .policy
= "writethrough",
98 .pte
= L_PTE_MT_WRITETHROUGH
,
99 .pte_s2
= s2_policy(L_PTE_S2_MT_WRITETHROUGH
),
101 .policy
= "writeback",
104 .pte
= L_PTE_MT_WRITEBACK
,
105 .pte_s2
= s2_policy(L_PTE_S2_MT_WRITEBACK
),
107 .policy
= "writealloc",
109 .pmd
= PMD_SECT_WBWA
,
110 .pte
= L_PTE_MT_WRITEALLOC
,
111 .pte_s2
= s2_policy(L_PTE_S2_MT_WRITEBACK
),
116 * These are useful for identifying cache coherency
117 * problems by allowing the cache or the cache and
118 * writebuffer to be turned off. (Note: the write
119 * buffer should not be on and the cache off).
121 static int __init
early_cachepolicy(char *p
)
125 for (i
= 0; i
< ARRAY_SIZE(cache_policies
); i
++) {
126 int len
= strlen(cache_policies
[i
].policy
);
128 if (memcmp(p
, cache_policies
[i
].policy
, len
) == 0) {
130 cr_alignment
&= ~cache_policies
[i
].cr_mask
;
131 cr_no_alignment
&= ~cache_policies
[i
].cr_mask
;
135 if (i
== ARRAY_SIZE(cache_policies
))
136 printk(KERN_ERR
"ERROR: unknown or unsupported cache policy\n");
138 * This restriction is partly to do with the way we boot; it is
139 * unpredictable to have memory mapped using two different sets of
140 * memory attributes (shared, type, and cache attribs). We can not
141 * change these attributes once the initial assembly has setup the
144 if (cpu_architecture() >= CPU_ARCH_ARMv6
) {
145 printk(KERN_WARNING
"Only cachepolicy=writeback supported on ARMv6 and later\n");
146 cachepolicy
= CPOLICY_WRITEBACK
;
149 set_cr(cr_alignment
);
152 early_param("cachepolicy", early_cachepolicy
);
154 static int __init
early_nocache(char *__unused
)
156 char *p
= "buffered";
157 printk(KERN_WARNING
"nocache is deprecated; use cachepolicy=%s\n", p
);
158 early_cachepolicy(p
);
161 early_param("nocache", early_nocache
);
163 static int __init
early_nowrite(char *__unused
)
165 char *p
= "uncached";
166 printk(KERN_WARNING
"nowb is deprecated; use cachepolicy=%s\n", p
);
167 early_cachepolicy(p
);
170 early_param("nowb", early_nowrite
);
172 #ifndef CONFIG_ARM_LPAE
173 static int __init
early_ecc(char *p
)
175 if (memcmp(p
, "on", 2) == 0)
176 ecc_mask
= PMD_PROTECTION
;
177 else if (memcmp(p
, "off", 3) == 0)
181 early_param("ecc", early_ecc
);
184 static int __init
noalign_setup(char *__unused
)
186 cr_alignment
&= ~CR_A
;
187 cr_no_alignment
&= ~CR_A
;
188 set_cr(cr_alignment
);
191 __setup("noalign", noalign_setup
);
194 void adjust_cr(unsigned long mask
, unsigned long set
)
202 local_irq_save(flags
);
204 cr_no_alignment
= (cr_no_alignment
& ~mask
) | set
;
205 cr_alignment
= (cr_alignment
& ~mask
) | set
;
207 set_cr((get_cr() & ~mask
) | set
);
209 local_irq_restore(flags
);
213 #define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN
214 #define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE
216 static struct mem_type mem_types
[] = {
217 [MT_DEVICE
] = { /* Strongly ordered / ARMv6 shared device */
218 .prot_pte
= PROT_PTE_DEVICE
| L_PTE_MT_DEV_SHARED
|
220 .prot_l1
= PMD_TYPE_TABLE
,
221 .prot_sect
= PROT_SECT_DEVICE
| PMD_SECT_S
,
224 [MT_DEVICE_NONSHARED
] = { /* ARMv6 non-shared device */
225 .prot_pte
= PROT_PTE_DEVICE
| L_PTE_MT_DEV_NONSHARED
,
226 .prot_l1
= PMD_TYPE_TABLE
,
227 .prot_sect
= PROT_SECT_DEVICE
,
230 [MT_DEVICE_CACHED
] = { /* ioremap_cached */
231 .prot_pte
= PROT_PTE_DEVICE
| L_PTE_MT_DEV_CACHED
,
232 .prot_l1
= PMD_TYPE_TABLE
,
233 .prot_sect
= PROT_SECT_DEVICE
| PMD_SECT_WB
,
236 [MT_DEVICE_WC
] = { /* ioremap_wc */
237 .prot_pte
= PROT_PTE_DEVICE
| L_PTE_MT_DEV_WC
,
238 .prot_l1
= PMD_TYPE_TABLE
,
239 .prot_sect
= PROT_SECT_DEVICE
,
243 .prot_pte
= PROT_PTE_DEVICE
,
244 .prot_l1
= PMD_TYPE_TABLE
,
245 .prot_sect
= PMD_TYPE_SECT
| PMD_SECT_XN
,
249 .prot_sect
= PMD_TYPE_SECT
| PMD_SECT_XN
,
250 .domain
= DOMAIN_KERNEL
,
252 #ifndef CONFIG_ARM_LPAE
254 .prot_sect
= PMD_TYPE_SECT
| PMD_SECT_XN
| PMD_SECT_MINICACHE
,
255 .domain
= DOMAIN_KERNEL
,
259 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
|
261 .prot_l1
= PMD_TYPE_TABLE
,
262 .domain
= DOMAIN_USER
,
264 [MT_HIGH_VECTORS
] = {
265 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
|
266 L_PTE_USER
| L_PTE_RDONLY
,
267 .prot_l1
= PMD_TYPE_TABLE
,
268 .domain
= DOMAIN_USER
,
271 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
,
272 .prot_l1
= PMD_TYPE_TABLE
,
273 .prot_sect
= PMD_TYPE_SECT
| PMD_SECT_AP_WRITE
,
274 .domain
= DOMAIN_KERNEL
,
277 .prot_sect
= PMD_TYPE_SECT
,
278 .domain
= DOMAIN_KERNEL
,
280 [MT_MEMORY_NONCACHED
] = {
281 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
|
283 .prot_l1
= PMD_TYPE_TABLE
,
284 .prot_sect
= PMD_TYPE_SECT
| PMD_SECT_AP_WRITE
,
285 .domain
= DOMAIN_KERNEL
,
288 .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_XN
,
292 .domain
= DOMAIN_KERNEL
,
295 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
,
296 .prot_l1
= PMD_TYPE_TABLE
,
297 .domain
= DOMAIN_KERNEL
,
300 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
|
301 L_PTE_MT_UNCACHED
| L_PTE_XN
,
302 .prot_l1
= PMD_TYPE_TABLE
,
303 .prot_sect
= PMD_TYPE_SECT
| PMD_SECT_AP_WRITE
| PMD_SECT_S
|
304 PMD_SECT_UNCACHED
| PMD_SECT_XN
,
305 .domain
= DOMAIN_KERNEL
,
307 [MT_MEMORY_DMA_READY
] = {
308 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
,
309 .prot_l1
= PMD_TYPE_TABLE
,
310 .domain
= DOMAIN_KERNEL
,
314 const struct mem_type
*get_mem_type(unsigned int type
)
316 return type
< ARRAY_SIZE(mem_types
) ? &mem_types
[type
] : NULL
;
318 EXPORT_SYMBOL(get_mem_type
);
321 * Adjust the PMD section entries according to the CPU in use.
323 static void __init
build_mem_type_table(void)
325 struct cachepolicy
*cp
;
326 unsigned int cr
= get_cr();
327 pteval_t user_pgprot
, kern_pgprot
, vecs_pgprot
;
328 pteval_t hyp_device_pgprot
, s2_pgprot
, s2_device_pgprot
;
329 int cpu_arch
= cpu_architecture();
332 if (cpu_arch
< CPU_ARCH_ARMv6
) {
333 #if defined(CONFIG_CPU_DCACHE_DISABLE)
334 if (cachepolicy
> CPOLICY_BUFFERED
)
335 cachepolicy
= CPOLICY_BUFFERED
;
336 #elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH)
337 if (cachepolicy
> CPOLICY_WRITETHROUGH
)
338 cachepolicy
= CPOLICY_WRITETHROUGH
;
341 if (cpu_arch
< CPU_ARCH_ARMv5
) {
342 if (cachepolicy
>= CPOLICY_WRITEALLOC
)
343 cachepolicy
= CPOLICY_WRITEBACK
;
347 cachepolicy
= CPOLICY_WRITEALLOC
;
350 * Strip out features not present on earlier architectures.
351 * Pre-ARMv5 CPUs don't have TEX bits. Pre-ARMv6 CPUs or those
352 * without extended page tables don't have the 'Shared' bit.
354 if (cpu_arch
< CPU_ARCH_ARMv5
)
355 for (i
= 0; i
< ARRAY_SIZE(mem_types
); i
++)
356 mem_types
[i
].prot_sect
&= ~PMD_SECT_TEX(7);
357 if ((cpu_arch
< CPU_ARCH_ARMv6
|| !(cr
& CR_XP
)) && !cpu_is_xsc3())
358 for (i
= 0; i
< ARRAY_SIZE(mem_types
); i
++)
359 mem_types
[i
].prot_sect
&= ~PMD_SECT_S
;
362 * ARMv5 and lower, bit 4 must be set for page tables (was: cache
363 * "update-able on write" bit on ARM610). However, Xscale and
364 * Xscale3 require this bit to be cleared.
366 if (cpu_is_xscale() || cpu_is_xsc3()) {
367 for (i
= 0; i
< ARRAY_SIZE(mem_types
); i
++) {
368 mem_types
[i
].prot_sect
&= ~PMD_BIT4
;
369 mem_types
[i
].prot_l1
&= ~PMD_BIT4
;
371 } else if (cpu_arch
< CPU_ARCH_ARMv6
) {
372 for (i
= 0; i
< ARRAY_SIZE(mem_types
); i
++) {
373 if (mem_types
[i
].prot_l1
)
374 mem_types
[i
].prot_l1
|= PMD_BIT4
;
375 if (mem_types
[i
].prot_sect
)
376 mem_types
[i
].prot_sect
|= PMD_BIT4
;
381 * Mark the device areas according to the CPU/architecture.
383 if (cpu_is_xsc3() || (cpu_arch
>= CPU_ARCH_ARMv6
&& (cr
& CR_XP
))) {
384 if (!cpu_is_xsc3()) {
386 * Mark device regions on ARMv6+ as execute-never
387 * to prevent speculative instruction fetches.
389 mem_types
[MT_DEVICE
].prot_sect
|= PMD_SECT_XN
;
390 mem_types
[MT_DEVICE_NONSHARED
].prot_sect
|= PMD_SECT_XN
;
391 mem_types
[MT_DEVICE_CACHED
].prot_sect
|= PMD_SECT_XN
;
392 mem_types
[MT_DEVICE_WC
].prot_sect
|= PMD_SECT_XN
;
394 if (cpu_arch
>= CPU_ARCH_ARMv7
&& (cr
& CR_TRE
)) {
396 * For ARMv7 with TEX remapping,
397 * - shared device is SXCB=1100
398 * - nonshared device is SXCB=0100
399 * - write combine device mem is SXCB=0001
400 * (Uncached Normal memory)
402 mem_types
[MT_DEVICE
].prot_sect
|= PMD_SECT_TEX(1);
403 mem_types
[MT_DEVICE_NONSHARED
].prot_sect
|= PMD_SECT_TEX(1);
404 mem_types
[MT_DEVICE_WC
].prot_sect
|= PMD_SECT_BUFFERABLE
;
405 } else if (cpu_is_xsc3()) {
408 * - shared device is TEXCB=00101
409 * - nonshared device is TEXCB=01000
410 * - write combine device mem is TEXCB=00100
411 * (Inner/Outer Uncacheable in xsc3 parlance)
413 mem_types
[MT_DEVICE
].prot_sect
|= PMD_SECT_TEX(1) | PMD_SECT_BUFFERED
;
414 mem_types
[MT_DEVICE_NONSHARED
].prot_sect
|= PMD_SECT_TEX(2);
415 mem_types
[MT_DEVICE_WC
].prot_sect
|= PMD_SECT_TEX(1);
418 * For ARMv6 and ARMv7 without TEX remapping,
419 * - shared device is TEXCB=00001
420 * - nonshared device is TEXCB=01000
421 * - write combine device mem is TEXCB=00100
422 * (Uncached Normal in ARMv6 parlance).
424 mem_types
[MT_DEVICE
].prot_sect
|= PMD_SECT_BUFFERED
;
425 mem_types
[MT_DEVICE_NONSHARED
].prot_sect
|= PMD_SECT_TEX(2);
426 mem_types
[MT_DEVICE_WC
].prot_sect
|= PMD_SECT_TEX(1);
430 * On others, write combining is "Uncached/Buffered"
432 mem_types
[MT_DEVICE_WC
].prot_sect
|= PMD_SECT_BUFFERABLE
;
436 * Now deal with the memory-type mappings
438 cp
= &cache_policies
[cachepolicy
];
439 vecs_pgprot
= kern_pgprot
= user_pgprot
= cp
->pte
;
440 s2_pgprot
= cp
->pte_s2
;
441 hyp_device_pgprot
= s2_device_pgprot
= mem_types
[MT_DEVICE
].prot_pte
;
444 * ARMv6 and above have extended page tables.
446 if (cpu_arch
>= CPU_ARCH_ARMv6
&& (cr
& CR_XP
)) {
447 #ifndef CONFIG_ARM_LPAE
449 * Mark cache clean areas and XIP ROM read only
450 * from SVC mode and no access from userspace.
452 mem_types
[MT_ROM
].prot_sect
|= PMD_SECT_APX
|PMD_SECT_AP_WRITE
;
453 mem_types
[MT_MINICLEAN
].prot_sect
|= PMD_SECT_APX
|PMD_SECT_AP_WRITE
;
454 mem_types
[MT_CACHECLEAN
].prot_sect
|= PMD_SECT_APX
|PMD_SECT_AP_WRITE
;
459 * Mark memory with the "shared" attribute
462 user_pgprot
|= L_PTE_SHARED
;
463 kern_pgprot
|= L_PTE_SHARED
;
464 vecs_pgprot
|= L_PTE_SHARED
;
465 s2_pgprot
|= L_PTE_SHARED
;
466 mem_types
[MT_DEVICE_WC
].prot_sect
|= PMD_SECT_S
;
467 mem_types
[MT_DEVICE_WC
].prot_pte
|= L_PTE_SHARED
;
468 mem_types
[MT_DEVICE_CACHED
].prot_sect
|= PMD_SECT_S
;
469 mem_types
[MT_DEVICE_CACHED
].prot_pte
|= L_PTE_SHARED
;
470 mem_types
[MT_MEMORY
].prot_sect
|= PMD_SECT_S
;
471 mem_types
[MT_MEMORY
].prot_pte
|= L_PTE_SHARED
;
472 mem_types
[MT_MEMORY_DMA_READY
].prot_pte
|= L_PTE_SHARED
;
473 mem_types
[MT_MEMORY_NONCACHED
].prot_sect
|= PMD_SECT_S
;
474 mem_types
[MT_MEMORY_NONCACHED
].prot_pte
|= L_PTE_SHARED
;
479 * Non-cacheable Normal - intended for memory areas that must
480 * not cause dirty cache line writebacks when used
482 if (cpu_arch
>= CPU_ARCH_ARMv6
) {
483 if (cpu_arch
>= CPU_ARCH_ARMv7
&& (cr
& CR_TRE
)) {
484 /* Non-cacheable Normal is XCB = 001 */
485 mem_types
[MT_MEMORY_NONCACHED
].prot_sect
|=
488 /* For both ARMv6 and non-TEX-remapping ARMv7 */
489 mem_types
[MT_MEMORY_NONCACHED
].prot_sect
|=
493 mem_types
[MT_MEMORY_NONCACHED
].prot_sect
|= PMD_SECT_BUFFERABLE
;
496 #ifdef CONFIG_ARM_LPAE
498 * Do not generate access flag faults for the kernel mappings.
500 for (i
= 0; i
< ARRAY_SIZE(mem_types
); i
++) {
501 mem_types
[i
].prot_pte
|= PTE_EXT_AF
;
502 if (mem_types
[i
].prot_sect
)
503 mem_types
[i
].prot_sect
|= PMD_SECT_AF
;
505 kern_pgprot
|= PTE_EXT_AF
;
506 vecs_pgprot
|= PTE_EXT_AF
;
509 for (i
= 0; i
< 16; i
++) {
510 pteval_t v
= pgprot_val(protection_map
[i
]);
511 protection_map
[i
] = __pgprot(v
| user_pgprot
);
514 mem_types
[MT_LOW_VECTORS
].prot_pte
|= vecs_pgprot
;
515 mem_types
[MT_HIGH_VECTORS
].prot_pte
|= vecs_pgprot
;
517 pgprot_user
= __pgprot(L_PTE_PRESENT
| L_PTE_YOUNG
| user_pgprot
);
518 pgprot_kernel
= __pgprot(L_PTE_PRESENT
| L_PTE_YOUNG
|
519 L_PTE_DIRTY
| kern_pgprot
);
520 pgprot_s2
= __pgprot(L_PTE_PRESENT
| L_PTE_YOUNG
| s2_pgprot
);
521 pgprot_s2_device
= __pgprot(s2_device_pgprot
);
522 pgprot_hyp_device
= __pgprot(hyp_device_pgprot
);
524 mem_types
[MT_LOW_VECTORS
].prot_l1
|= ecc_mask
;
525 mem_types
[MT_HIGH_VECTORS
].prot_l1
|= ecc_mask
;
526 mem_types
[MT_MEMORY
].prot_sect
|= ecc_mask
| cp
->pmd
;
527 mem_types
[MT_MEMORY
].prot_pte
|= kern_pgprot
;
528 mem_types
[MT_MEMORY_DMA_READY
].prot_pte
|= kern_pgprot
;
529 mem_types
[MT_MEMORY_NONCACHED
].prot_sect
|= ecc_mask
;
530 mem_types
[MT_ROM
].prot_sect
|= cp
->pmd
;
534 mem_types
[MT_CACHECLEAN
].prot_sect
|= PMD_SECT_WT
;
538 mem_types
[MT_CACHECLEAN
].prot_sect
|= PMD_SECT_WB
;
541 printk("Memory policy: ECC %sabled, Data cache %s\n",
542 ecc_mask
? "en" : "dis", cp
->policy
);
544 for (i
= 0; i
< ARRAY_SIZE(mem_types
); i
++) {
545 struct mem_type
*t
= &mem_types
[i
];
547 t
->prot_l1
|= PMD_DOMAIN(t
->domain
);
549 t
->prot_sect
|= PMD_DOMAIN(t
->domain
);
553 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
554 pgprot_t
phys_mem_access_prot(struct file
*file
, unsigned long pfn
,
555 unsigned long size
, pgprot_t vma_prot
)
558 return pgprot_noncached(vma_prot
);
559 else if (file
->f_flags
& O_SYNC
)
560 return pgprot_writecombine(vma_prot
);
563 EXPORT_SYMBOL(phys_mem_access_prot
);
566 #define vectors_base() (vectors_high() ? 0xffff0000 : 0)
568 static void __init
*early_alloc_aligned(unsigned long sz
, unsigned long align
)
570 void *ptr
= __va(memblock_alloc(sz
, align
));
575 static void __init
*early_alloc(unsigned long sz
)
577 return early_alloc_aligned(sz
, sz
);
580 static pte_t
* __init
early_pte_alloc(pmd_t
*pmd
, unsigned long addr
, unsigned long prot
)
582 if (pmd_none(*pmd
)) {
583 pte_t
*pte
= early_alloc(PTE_HWTABLE_OFF
+ PTE_HWTABLE_SIZE
);
584 __pmd_populate(pmd
, __pa(pte
), prot
);
586 BUG_ON(pmd_bad(*pmd
));
587 return pte_offset_kernel(pmd
, addr
);
590 static void __init
alloc_init_pte(pmd_t
*pmd
, unsigned long addr
,
591 unsigned long end
, unsigned long pfn
,
592 const struct mem_type
*type
)
594 pte_t
*pte
= early_pte_alloc(pmd
, addr
, type
->prot_l1
);
596 set_pte_ext(pte
, pfn_pte(pfn
, __pgprot(type
->prot_pte
)), 0);
598 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
601 static void __init
map_init_section(pmd_t
*pmd
, unsigned long addr
,
602 unsigned long end
, phys_addr_t phys
,
603 const struct mem_type
*type
)
605 #ifndef CONFIG_ARM_LPAE
607 * In classic MMU format, puds and pmds are folded in to
608 * the pgds. pmd_offset gives the PGD entry. PGDs refer to a
609 * group of L1 entries making up one logical pointer to
610 * an L2 table (2MB), where as PMDs refer to the individual
611 * L1 entries (1MB). Hence increment to get the correct
612 * offset for odd 1MB sections.
613 * (See arch/arm/include/asm/pgtable-2level.h)
615 if (addr
& SECTION_SIZE
)
619 *pmd
= __pmd(phys
| type
->prot_sect
);
620 phys
+= SECTION_SIZE
;
621 } while (pmd
++, addr
+= SECTION_SIZE
, addr
!= end
);
623 flush_pmd_entry(pmd
);
626 static void __init
alloc_init_pmd(pud_t
*pud
, unsigned long addr
,
627 unsigned long end
, phys_addr_t phys
,
628 const struct mem_type
*type
)
630 pmd_t
*pmd
= pmd_offset(pud
, addr
);
635 * With LPAE, we must loop over to map
636 * all the pmds for the given range.
638 next
= pmd_addr_end(addr
, end
);
641 * Try a section mapping - addr, next and phys must all be
642 * aligned to a section boundary.
644 if (type
->prot_sect
&&
645 ((addr
| next
| phys
) & ~SECTION_MASK
) == 0) {
646 map_init_section(pmd
, addr
, next
, phys
, type
);
648 alloc_init_pte(pmd
, addr
, next
,
649 __phys_to_pfn(phys
), type
);
654 } while (pmd
++, addr
= next
, addr
!= end
);
657 static void __init
alloc_init_pud(pgd_t
*pgd
, unsigned long addr
,
658 unsigned long end
, unsigned long phys
, const struct mem_type
*type
)
660 pud_t
*pud
= pud_offset(pgd
, addr
);
664 next
= pud_addr_end(addr
, end
);
665 alloc_init_pmd(pud
, addr
, next
, phys
, type
);
667 } while (pud
++, addr
= next
, addr
!= end
);
670 #ifndef CONFIG_ARM_LPAE
671 static void __init
create_36bit_mapping(struct map_desc
*md
,
672 const struct mem_type
*type
)
674 unsigned long addr
, length
, end
;
679 phys
= __pfn_to_phys(md
->pfn
);
680 length
= PAGE_ALIGN(md
->length
);
682 if (!(cpu_architecture() >= CPU_ARCH_ARMv6
|| cpu_is_xsc3())) {
683 printk(KERN_ERR
"MM: CPU does not support supersection "
684 "mapping for 0x%08llx at 0x%08lx\n",
685 (long long)__pfn_to_phys((u64
)md
->pfn
), addr
);
689 /* N.B. ARMv6 supersections are only defined to work with domain 0.
690 * Since domain assignments can in fact be arbitrary, the
691 * 'domain == 0' check below is required to insure that ARMv6
692 * supersections are only allocated for domain 0 regardless
693 * of the actual domain assignments in use.
696 printk(KERN_ERR
"MM: invalid domain in supersection "
697 "mapping for 0x%08llx at 0x%08lx\n",
698 (long long)__pfn_to_phys((u64
)md
->pfn
), addr
);
702 if ((addr
| length
| __pfn_to_phys(md
->pfn
)) & ~SUPERSECTION_MASK
) {
703 printk(KERN_ERR
"MM: cannot create mapping for 0x%08llx"
704 " at 0x%08lx invalid alignment\n",
705 (long long)__pfn_to_phys((u64
)md
->pfn
), addr
);
710 * Shift bits [35:32] of address into bits [23:20] of PMD
713 phys
|= (((md
->pfn
>> (32 - PAGE_SHIFT
)) & 0xF) << 20);
715 pgd
= pgd_offset_k(addr
);
718 pud_t
*pud
= pud_offset(pgd
, addr
);
719 pmd_t
*pmd
= pmd_offset(pud
, addr
);
722 for (i
= 0; i
< 16; i
++)
723 *pmd
++ = __pmd(phys
| type
->prot_sect
| PMD_SECT_SUPER
);
725 addr
+= SUPERSECTION_SIZE
;
726 phys
+= SUPERSECTION_SIZE
;
727 pgd
+= SUPERSECTION_SIZE
>> PGDIR_SHIFT
;
728 } while (addr
!= end
);
730 #endif /* !CONFIG_ARM_LPAE */
733 * Create the page directory entries and any necessary
734 * page tables for the mapping specified by `md'. We
735 * are able to cope here with varying sizes and address
736 * offsets, and we take full advantage of sections and
739 static void __init
create_mapping(struct map_desc
*md
)
741 unsigned long addr
, length
, end
;
743 const struct mem_type
*type
;
746 if (md
->virtual != vectors_base() && md
->virtual < TASK_SIZE
) {
747 printk(KERN_WARNING
"BUG: not creating mapping for 0x%08llx"
748 " at 0x%08lx in user region\n",
749 (long long)__pfn_to_phys((u64
)md
->pfn
), md
->virtual);
753 if ((md
->type
== MT_DEVICE
|| md
->type
== MT_ROM
) &&
754 md
->virtual >= PAGE_OFFSET
&&
755 (md
->virtual < VMALLOC_START
|| md
->virtual >= VMALLOC_END
)) {
756 printk(KERN_WARNING
"BUG: mapping for 0x%08llx"
757 " at 0x%08lx out of vmalloc space\n",
758 (long long)__pfn_to_phys((u64
)md
->pfn
), md
->virtual);
761 type
= &mem_types
[md
->type
];
763 #ifndef CONFIG_ARM_LPAE
765 * Catch 36-bit addresses
767 if (md
->pfn
>= 0x100000) {
768 create_36bit_mapping(md
, type
);
773 addr
= md
->virtual & PAGE_MASK
;
774 phys
= __pfn_to_phys(md
->pfn
);
775 length
= PAGE_ALIGN(md
->length
+ (md
->virtual & ~PAGE_MASK
));
777 if (type
->prot_l1
== 0 && ((addr
| phys
| length
) & ~SECTION_MASK
)) {
778 printk(KERN_WARNING
"BUG: map for 0x%08llx at 0x%08lx can not "
779 "be mapped using pages, ignoring.\n",
780 (long long)__pfn_to_phys(md
->pfn
), addr
);
784 pgd
= pgd_offset_k(addr
);
787 unsigned long next
= pgd_addr_end(addr
, end
);
789 alloc_init_pud(pgd
, addr
, next
, phys
, type
);
793 } while (pgd
++, addr
!= end
);
797 * Create the architecture specific mappings
799 void __init
iotable_init(struct map_desc
*io_desc
, int nr
)
802 struct vm_struct
*vm
;
803 struct static_vm
*svm
;
808 svm
= early_alloc_aligned(sizeof(*svm
) * nr
, __alignof__(*svm
));
810 for (md
= io_desc
; nr
; md
++, nr
--) {
814 vm
->addr
= (void *)(md
->virtual & PAGE_MASK
);
815 vm
->size
= PAGE_ALIGN(md
->length
+ (md
->virtual & ~PAGE_MASK
));
816 vm
->phys_addr
= __pfn_to_phys(md
->pfn
);
817 vm
->flags
= VM_IOREMAP
| VM_ARM_STATIC_MAPPING
;
818 vm
->flags
|= VM_ARM_MTYPE(md
->type
);
819 vm
->caller
= iotable_init
;
820 add_static_vm_early(svm
++);
824 void __init
vm_reserve_area_early(unsigned long addr
, unsigned long size
,
827 struct vm_struct
*vm
;
828 struct static_vm
*svm
;
830 svm
= early_alloc_aligned(sizeof(*svm
), __alignof__(*svm
));
833 vm
->addr
= (void *)addr
;
835 vm
->flags
= VM_IOREMAP
| VM_ARM_EMPTY_MAPPING
;
837 add_static_vm_early(svm
);
840 #ifndef CONFIG_ARM_LPAE
843 * The Linux PMD is made of two consecutive section entries covering 2MB
844 * (see definition in include/asm/pgtable-2level.h). However a call to
845 * create_mapping() may optimize static mappings by using individual
846 * 1MB section mappings. This leaves the actual PMD potentially half
847 * initialized if the top or bottom section entry isn't used, leaving it
848 * open to problems if a subsequent ioremap() or vmalloc() tries to use
849 * the virtual space left free by that unused section entry.
851 * Let's avoid the issue by inserting dummy vm entries covering the unused
852 * PMD halves once the static mappings are in place.
855 static void __init
pmd_empty_section_gap(unsigned long addr
)
857 vm_reserve_area_early(addr
, SECTION_SIZE
, pmd_empty_section_gap
);
860 static void __init
fill_pmd_gaps(void)
862 struct static_vm
*svm
;
863 struct vm_struct
*vm
;
864 unsigned long addr
, next
= 0;
867 list_for_each_entry(svm
, &static_vmlist
, list
) {
869 addr
= (unsigned long)vm
->addr
;
874 * Check if this vm starts on an odd section boundary.
875 * If so and the first section entry for this PMD is free
876 * then we block the corresponding virtual address.
878 if ((addr
& ~PMD_MASK
) == SECTION_SIZE
) {
879 pmd
= pmd_off_k(addr
);
881 pmd_empty_section_gap(addr
& PMD_MASK
);
885 * Then check if this vm ends on an odd section boundary.
886 * If so and the second section entry for this PMD is empty
887 * then we block the corresponding virtual address.
890 if ((addr
& ~PMD_MASK
) == SECTION_SIZE
) {
891 pmd
= pmd_off_k(addr
) + 1;
893 pmd_empty_section_gap(addr
);
896 /* no need to look at any vm entry until we hit the next PMD */
897 next
= (addr
+ PMD_SIZE
- 1) & PMD_MASK
;
902 #define fill_pmd_gaps() do { } while (0)
905 #if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
906 static void __init
pci_reserve_io(void)
908 struct static_vm
*svm
;
910 svm
= find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE
);
914 vm_reserve_area_early(PCI_IO_VIRT_BASE
, SZ_2M
, pci_reserve_io
);
917 #define pci_reserve_io() do { } while (0)
920 #ifdef CONFIG_DEBUG_LL
921 void __init
debug_ll_io_init(void)
925 debug_ll_addr(&map
.pfn
, &map
.virtual);
926 if (!map
.pfn
|| !map
.virtual)
928 map
.pfn
= __phys_to_pfn(map
.pfn
);
929 map
.virtual &= PAGE_MASK
;
930 map
.length
= PAGE_SIZE
;
931 map
.type
= MT_DEVICE
;
932 create_mapping(&map
);
936 static void * __initdata vmalloc_min
=
937 (void *)(VMALLOC_END
- (240 << 20) - VMALLOC_OFFSET
);
940 * vmalloc=size forces the vmalloc area to be exactly 'size'
941 * bytes. This can be used to increase (or decrease) the vmalloc
942 * area - the default is 240m.
944 static int __init
early_vmalloc(char *arg
)
946 unsigned long vmalloc_reserve
= memparse(arg
, NULL
);
948 if (vmalloc_reserve
< SZ_16M
) {
949 vmalloc_reserve
= SZ_16M
;
951 "vmalloc area too small, limiting to %luMB\n",
952 vmalloc_reserve
>> 20);
955 if (vmalloc_reserve
> VMALLOC_END
- (PAGE_OFFSET
+ SZ_32M
)) {
956 vmalloc_reserve
= VMALLOC_END
- (PAGE_OFFSET
+ SZ_32M
);
958 "vmalloc area is too big, limiting to %luMB\n",
959 vmalloc_reserve
>> 20);
962 vmalloc_min
= (void *)(VMALLOC_END
- vmalloc_reserve
);
965 early_param("vmalloc", early_vmalloc
);
967 phys_addr_t arm_lowmem_limit __initdata
= 0;
969 void __init
sanity_check_meminfo(void)
971 int i
, j
, highmem
= 0;
973 for (i
= 0, j
= 0; i
< meminfo
.nr_banks
; i
++) {
974 struct membank
*bank
= &meminfo
.bank
[j
];
975 *bank
= meminfo
.bank
[i
];
977 if (bank
->start
> ULONG_MAX
)
980 #ifdef CONFIG_HIGHMEM
981 if (__va(bank
->start
) >= vmalloc_min
||
982 __va(bank
->start
) < (void *)PAGE_OFFSET
)
985 bank
->highmem
= highmem
;
988 * Split those memory banks which are partially overlapping
989 * the vmalloc area greatly simplifying things later.
991 if (!highmem
&& __va(bank
->start
) < vmalloc_min
&&
992 bank
->size
> vmalloc_min
- __va(bank
->start
)) {
993 if (meminfo
.nr_banks
>= NR_BANKS
) {
994 printk(KERN_CRIT
"NR_BANKS too low, "
995 "ignoring high memory\n");
997 memmove(bank
+ 1, bank
,
998 (meminfo
.nr_banks
- i
) * sizeof(*bank
));
1001 bank
[1].size
-= vmalloc_min
- __va(bank
->start
);
1002 bank
[1].start
= __pa(vmalloc_min
- 1) + 1;
1003 bank
[1].highmem
= highmem
= 1;
1006 bank
->size
= vmalloc_min
- __va(bank
->start
);
1009 bank
->highmem
= highmem
;
1012 * Highmem banks not allowed with !CONFIG_HIGHMEM.
1015 printk(KERN_NOTICE
"Ignoring RAM at %.8llx-%.8llx "
1016 "(!CONFIG_HIGHMEM).\n",
1017 (unsigned long long)bank
->start
,
1018 (unsigned long long)bank
->start
+ bank
->size
- 1);
1023 * Check whether this memory bank would entirely overlap
1026 if (__va(bank
->start
) >= vmalloc_min
||
1027 __va(bank
->start
) < (void *)PAGE_OFFSET
) {
1028 printk(KERN_NOTICE
"Ignoring RAM at %.8llx-%.8llx "
1029 "(vmalloc region overlap).\n",
1030 (unsigned long long)bank
->start
,
1031 (unsigned long long)bank
->start
+ bank
->size
- 1);
1036 * Check whether this memory bank would partially overlap
1039 if (__va(bank
->start
+ bank
->size
- 1) >= vmalloc_min
||
1040 __va(bank
->start
+ bank
->size
- 1) <= __va(bank
->start
)) {
1041 unsigned long newsize
= vmalloc_min
- __va(bank
->start
);
1042 printk(KERN_NOTICE
"Truncating RAM at %.8llx-%.8llx "
1043 "to -%.8llx (vmalloc region overlap).\n",
1044 (unsigned long long)bank
->start
,
1045 (unsigned long long)bank
->start
+ bank
->size
- 1,
1046 (unsigned long long)bank
->start
+ newsize
- 1);
1047 bank
->size
= newsize
;
1050 if (!bank
->highmem
&& bank
->start
+ bank
->size
> arm_lowmem_limit
)
1051 arm_lowmem_limit
= bank
->start
+ bank
->size
;
1055 #ifdef CONFIG_HIGHMEM
1057 const char *reason
= NULL
;
1059 if (cache_is_vipt_aliasing()) {
1061 * Interactions between kmap and other mappings
1062 * make highmem support with aliasing VIPT caches
1065 reason
= "with VIPT aliasing cache";
1068 printk(KERN_CRIT
"HIGHMEM is not supported %s, ignoring high memory\n",
1070 while (j
> 0 && meminfo
.bank
[j
- 1].highmem
)
1075 meminfo
.nr_banks
= j
;
1076 high_memory
= __va(arm_lowmem_limit
- 1) + 1;
1077 memblock_set_current_limit(arm_lowmem_limit
);
1080 static inline void prepare_page_table(void)
1086 * Clear out all the mappings below the kernel image.
1088 for (addr
= 0; addr
< MODULES_VADDR
; addr
+= PMD_SIZE
)
1089 pmd_clear(pmd_off_k(addr
));
1091 #ifdef CONFIG_XIP_KERNEL
1092 /* The XIP kernel is mapped in the module area -- skip over it */
1093 addr
= ((unsigned long)_etext
+ PMD_SIZE
- 1) & PMD_MASK
;
1095 for ( ; addr
< PAGE_OFFSET
; addr
+= PMD_SIZE
)
1096 pmd_clear(pmd_off_k(addr
));
1099 * Find the end of the first block of lowmem.
1101 end
= memblock
.memory
.regions
[0].base
+ memblock
.memory
.regions
[0].size
;
1102 if (end
>= arm_lowmem_limit
)
1103 end
= arm_lowmem_limit
;
1106 * Clear out all the kernel space mappings, except for the first
1107 * memory bank, up to the vmalloc region.
1109 for (addr
= __phys_to_virt(end
);
1110 addr
< VMALLOC_START
; addr
+= PMD_SIZE
)
1111 pmd_clear(pmd_off_k(addr
));
1114 #ifdef CONFIG_ARM_LPAE
1115 /* the first page is reserved for pgd */
1116 #define SWAPPER_PG_DIR_SIZE (PAGE_SIZE + \
1117 PTRS_PER_PGD * PTRS_PER_PMD * sizeof(pmd_t))
1119 #define SWAPPER_PG_DIR_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
1123 * Reserve the special regions of memory
1125 void __init
arm_mm_memblock_reserve(void)
1128 * Reserve the page tables. These are already in use,
1129 * and can only be in node 0.
1131 memblock_reserve(__pa(swapper_pg_dir
), SWAPPER_PG_DIR_SIZE
);
1133 #ifdef CONFIG_SA1111
1135 * Because of the SA1111 DMA bug, we want to preserve our
1136 * precious DMA-able memory...
1138 memblock_reserve(PHYS_OFFSET
, __pa(swapper_pg_dir
) - PHYS_OFFSET
);
1143 * Set up the device mappings. Since we clear out the page tables for all
1144 * mappings above VMALLOC_START, we will remove any debug device mappings.
1145 * This means you have to be careful how you debug this function, or any
1146 * called function. This means you can't use any function or debugging
1147 * method which may touch any device, otherwise the kernel _will_ crash.
1149 static void __init
devicemaps_init(struct machine_desc
*mdesc
)
1151 struct map_desc map
;
1156 * Allocate the vector page early.
1158 vectors
= early_alloc(PAGE_SIZE
);
1160 early_trap_init(vectors
);
1162 for (addr
= VMALLOC_START
; addr
; addr
+= PMD_SIZE
)
1163 pmd_clear(pmd_off_k(addr
));
1166 * Map the kernel if it is XIP.
1167 * It is always first in the modulearea.
1169 #ifdef CONFIG_XIP_KERNEL
1170 map
.pfn
= __phys_to_pfn(CONFIG_XIP_PHYS_ADDR
& SECTION_MASK
);
1171 map
.virtual = MODULES_VADDR
;
1172 map
.length
= ((unsigned long)_etext
- map
.virtual + ~SECTION_MASK
) & SECTION_MASK
;
1174 create_mapping(&map
);
1178 * Map the cache flushing regions.
1181 map
.pfn
= __phys_to_pfn(FLUSH_BASE_PHYS
);
1182 map
.virtual = FLUSH_BASE
;
1184 map
.type
= MT_CACHECLEAN
;
1185 create_mapping(&map
);
1187 #ifdef FLUSH_BASE_MINICACHE
1188 map
.pfn
= __phys_to_pfn(FLUSH_BASE_PHYS
+ SZ_1M
);
1189 map
.virtual = FLUSH_BASE_MINICACHE
;
1191 map
.type
= MT_MINICLEAN
;
1192 create_mapping(&map
);
1196 * Create a mapping for the machine vectors at the high-vectors
1197 * location (0xffff0000). If we aren't using high-vectors, also
1198 * create a mapping at the low-vectors virtual address.
1200 map
.pfn
= __phys_to_pfn(virt_to_phys(vectors
));
1201 map
.virtual = 0xffff0000;
1202 map
.length
= PAGE_SIZE
;
1203 map
.type
= MT_HIGH_VECTORS
;
1204 create_mapping(&map
);
1206 if (!vectors_high()) {
1208 map
.type
= MT_LOW_VECTORS
;
1209 create_mapping(&map
);
1213 * Ask the machine support to map in the statically mapped devices.
1219 /* Reserve fixed i/o space in VMALLOC region */
1223 * Finally flush the caches and tlb to ensure that we're in a
1224 * consistent state wrt the writebuffer. This also ensures that
1225 * any write-allocated cache lines in the vector page are written
1226 * back. After this point, we can start to touch devices again.
1228 local_flush_tlb_all();
1232 static void __init
kmap_init(void)
1234 #ifdef CONFIG_HIGHMEM
1235 pkmap_page_table
= early_pte_alloc(pmd_off_k(PKMAP_BASE
),
1236 PKMAP_BASE
, _PAGE_KERNEL_TABLE
);
1240 static void __init
map_lowmem(void)
1242 struct memblock_region
*reg
;
1244 /* Map all the lowmem memory banks. */
1245 for_each_memblock(memory
, reg
) {
1246 phys_addr_t start
= reg
->base
;
1247 phys_addr_t end
= start
+ reg
->size
;
1248 struct map_desc map
;
1250 if (end
> arm_lowmem_limit
)
1251 end
= arm_lowmem_limit
;
1255 map
.pfn
= __phys_to_pfn(start
);
1256 map
.virtual = __phys_to_virt(start
);
1257 map
.length
= end
- start
;
1258 map
.type
= MT_MEMORY
;
1260 create_mapping(&map
);
1265 * paging_init() sets up the page tables, initialises the zone memory
1266 * maps, and sets up the zero page, bad page and bad page tables.
1268 void __init
paging_init(struct machine_desc
*mdesc
)
1272 memblock_set_current_limit(arm_lowmem_limit
);
1274 build_mem_type_table();
1275 prepare_page_table();
1277 dma_contiguous_remap();
1278 devicemaps_init(mdesc
);
1281 top_pmd
= pmd_off_k(0xffff0000);
1283 /* allocate the zero page. */
1284 zero_page
= early_alloc(PAGE_SIZE
);
1288 empty_zero_page
= virt_to_page(zero_page
);
1289 __flush_dcache_page(NULL
, empty_zero_page
);