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>
19 #include <asm/cputype.h>
20 #include <asm/sections.h>
21 #include <asm/cachetype.h>
22 #include <asm/setup.h>
23 #include <asm/sizes.h>
24 #include <asm/smp_plat.h>
26 #include <asm/highmem.h>
28 #include <asm/mach/arch.h>
29 #include <asm/mach/map.h>
33 DEFINE_PER_CPU(struct mmu_gather
, mmu_gathers
);
36 * empty_zero_page is a special page that is used for
37 * zero-initialized data and COW.
39 struct page
*empty_zero_page
;
40 EXPORT_SYMBOL(empty_zero_page
);
43 * The pmd table for the upper-most set of pages.
47 #define CPOLICY_UNCACHED 0
48 #define CPOLICY_BUFFERED 1
49 #define CPOLICY_WRITETHROUGH 2
50 #define CPOLICY_WRITEBACK 3
51 #define CPOLICY_WRITEALLOC 4
53 static unsigned int cachepolicy __initdata
= CPOLICY_WRITEBACK
;
54 static unsigned int ecc_mask __initdata
= 0;
56 pgprot_t pgprot_kernel
;
58 EXPORT_SYMBOL(pgprot_user
);
59 EXPORT_SYMBOL(pgprot_kernel
);
62 const char policy
[16];
68 static struct cachepolicy cache_policies
[] __initdata
= {
72 .pmd
= PMD_SECT_UNCACHED
,
73 .pte
= L_PTE_MT_UNCACHED
,
77 .pmd
= PMD_SECT_BUFFERED
,
78 .pte
= L_PTE_MT_BUFFERABLE
,
80 .policy
= "writethrough",
83 .pte
= L_PTE_MT_WRITETHROUGH
,
85 .policy
= "writeback",
88 .pte
= L_PTE_MT_WRITEBACK
,
90 .policy
= "writealloc",
93 .pte
= L_PTE_MT_WRITEALLOC
,
98 * These are useful for identifying cache coherency
99 * problems by allowing the cache or the cache and
100 * writebuffer to be turned off. (Note: the write
101 * buffer should not be on and the cache off).
103 static int __init
early_cachepolicy(char *p
)
107 for (i
= 0; i
< ARRAY_SIZE(cache_policies
); i
++) {
108 int len
= strlen(cache_policies
[i
].policy
);
110 if (memcmp(p
, cache_policies
[i
].policy
, len
) == 0) {
112 cr_alignment
&= ~cache_policies
[i
].cr_mask
;
113 cr_no_alignment
&= ~cache_policies
[i
].cr_mask
;
117 if (i
== ARRAY_SIZE(cache_policies
))
118 printk(KERN_ERR
"ERROR: unknown or unsupported cache policy\n");
120 * This restriction is partly to do with the way we boot; it is
121 * unpredictable to have memory mapped using two different sets of
122 * memory attributes (shared, type, and cache attribs). We can not
123 * change these attributes once the initial assembly has setup the
126 if (cpu_architecture() >= CPU_ARCH_ARMv6
) {
127 printk(KERN_WARNING
"Only cachepolicy=writeback supported on ARMv6 and later\n");
128 cachepolicy
= CPOLICY_WRITEBACK
;
131 set_cr(cr_alignment
);
134 early_param("cachepolicy", early_cachepolicy
);
136 static int __init
early_nocache(char *__unused
)
138 char *p
= "buffered";
139 printk(KERN_WARNING
"nocache is deprecated; use cachepolicy=%s\n", p
);
140 early_cachepolicy(p
);
143 early_param("nocache", early_nocache
);
145 static int __init
early_nowrite(char *__unused
)
147 char *p
= "uncached";
148 printk(KERN_WARNING
"nowb is deprecated; use cachepolicy=%s\n", p
);
149 early_cachepolicy(p
);
152 early_param("nowb", early_nowrite
);
154 static int __init
early_ecc(char *p
)
156 if (memcmp(p
, "on", 2) == 0)
157 ecc_mask
= PMD_PROTECTION
;
158 else if (memcmp(p
, "off", 3) == 0)
162 early_param("ecc", early_ecc
);
164 static int __init
noalign_setup(char *__unused
)
166 cr_alignment
&= ~CR_A
;
167 cr_no_alignment
&= ~CR_A
;
168 set_cr(cr_alignment
);
171 __setup("noalign", noalign_setup
);
174 void adjust_cr(unsigned long mask
, unsigned long set
)
182 local_irq_save(flags
);
184 cr_no_alignment
= (cr_no_alignment
& ~mask
) | set
;
185 cr_alignment
= (cr_alignment
& ~mask
) | set
;
187 set_cr((get_cr() & ~mask
) | set
);
189 local_irq_restore(flags
);
193 #define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN
194 #define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE
196 static struct mem_type mem_types
[] = {
197 [MT_DEVICE
] = { /* Strongly ordered / ARMv6 shared device */
198 .prot_pte
= PROT_PTE_DEVICE
| L_PTE_MT_DEV_SHARED
|
200 .prot_l1
= PMD_TYPE_TABLE
,
201 .prot_sect
= PROT_SECT_DEVICE
| PMD_SECT_S
,
204 [MT_DEVICE_NONSHARED
] = { /* ARMv6 non-shared device */
205 .prot_pte
= PROT_PTE_DEVICE
| L_PTE_MT_DEV_NONSHARED
,
206 .prot_l1
= PMD_TYPE_TABLE
,
207 .prot_sect
= PROT_SECT_DEVICE
,
210 [MT_DEVICE_CACHED
] = { /* ioremap_cached */
211 .prot_pte
= PROT_PTE_DEVICE
| L_PTE_MT_DEV_CACHED
,
212 .prot_l1
= PMD_TYPE_TABLE
,
213 .prot_sect
= PROT_SECT_DEVICE
| PMD_SECT_WB
,
216 [MT_DEVICE_WC
] = { /* ioremap_wc */
217 .prot_pte
= PROT_PTE_DEVICE
| L_PTE_MT_DEV_WC
,
218 .prot_l1
= PMD_TYPE_TABLE
,
219 .prot_sect
= PROT_SECT_DEVICE
,
223 .prot_pte
= PROT_PTE_DEVICE
,
224 .prot_l1
= PMD_TYPE_TABLE
,
225 .prot_sect
= PMD_TYPE_SECT
| PMD_SECT_XN
,
229 .prot_sect
= PMD_TYPE_SECT
| PMD_SECT_XN
,
230 .domain
= DOMAIN_KERNEL
,
233 .prot_sect
= PMD_TYPE_SECT
| PMD_SECT_XN
| PMD_SECT_MINICACHE
,
234 .domain
= DOMAIN_KERNEL
,
237 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
|
239 .prot_l1
= PMD_TYPE_TABLE
,
240 .domain
= DOMAIN_USER
,
242 [MT_HIGH_VECTORS
] = {
243 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
|
244 L_PTE_USER
| L_PTE_RDONLY
,
245 .prot_l1
= PMD_TYPE_TABLE
,
246 .domain
= DOMAIN_USER
,
249 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
,
250 .prot_l1
= PMD_TYPE_TABLE
,
251 .prot_sect
= PMD_TYPE_SECT
| PMD_SECT_AP_WRITE
,
252 .domain
= DOMAIN_KERNEL
,
255 .prot_sect
= PMD_TYPE_SECT
,
256 .domain
= DOMAIN_KERNEL
,
258 [MT_MEMORY_NONCACHED
] = {
259 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
|
261 .prot_l1
= PMD_TYPE_TABLE
,
262 .prot_sect
= PMD_TYPE_SECT
| PMD_SECT_AP_WRITE
,
263 .domain
= DOMAIN_KERNEL
,
266 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
|
268 .prot_l1
= PMD_TYPE_TABLE
,
269 .prot_sect
= PMD_TYPE_SECT
| PMD_SECT_XN
,
270 .domain
= DOMAIN_KERNEL
,
273 .prot_pte
= L_PTE_PRESENT
| L_PTE_YOUNG
| L_PTE_DIRTY
,
274 .prot_l1
= PMD_TYPE_TABLE
,
275 .domain
= DOMAIN_KERNEL
,
279 const struct mem_type
*get_mem_type(unsigned int type
)
281 return type
< ARRAY_SIZE(mem_types
) ? &mem_types
[type
] : NULL
;
283 EXPORT_SYMBOL(get_mem_type
);
286 * Adjust the PMD section entries according to the CPU in use.
288 static void __init
build_mem_type_table(void)
290 struct cachepolicy
*cp
;
291 unsigned int cr
= get_cr();
292 unsigned int user_pgprot
, kern_pgprot
, vecs_pgprot
;
293 int cpu_arch
= cpu_architecture();
296 if (cpu_arch
< CPU_ARCH_ARMv6
) {
297 #if defined(CONFIG_CPU_DCACHE_DISABLE)
298 if (cachepolicy
> CPOLICY_BUFFERED
)
299 cachepolicy
= CPOLICY_BUFFERED
;
300 #elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH)
301 if (cachepolicy
> CPOLICY_WRITETHROUGH
)
302 cachepolicy
= CPOLICY_WRITETHROUGH
;
305 if (cpu_arch
< CPU_ARCH_ARMv5
) {
306 if (cachepolicy
>= CPOLICY_WRITEALLOC
)
307 cachepolicy
= CPOLICY_WRITEBACK
;
311 cachepolicy
= CPOLICY_WRITEALLOC
;
314 * Strip out features not present on earlier architectures.
315 * Pre-ARMv5 CPUs don't have TEX bits. Pre-ARMv6 CPUs or those
316 * without extended page tables don't have the 'Shared' bit.
318 if (cpu_arch
< CPU_ARCH_ARMv5
)
319 for (i
= 0; i
< ARRAY_SIZE(mem_types
); i
++)
320 mem_types
[i
].prot_sect
&= ~PMD_SECT_TEX(7);
321 if ((cpu_arch
< CPU_ARCH_ARMv6
|| !(cr
& CR_XP
)) && !cpu_is_xsc3())
322 for (i
= 0; i
< ARRAY_SIZE(mem_types
); i
++)
323 mem_types
[i
].prot_sect
&= ~PMD_SECT_S
;
326 * ARMv5 and lower, bit 4 must be set for page tables (was: cache
327 * "update-able on write" bit on ARM610). However, Xscale and
328 * Xscale3 require this bit to be cleared.
330 if (cpu_is_xscale() || cpu_is_xsc3()) {
331 for (i
= 0; i
< ARRAY_SIZE(mem_types
); i
++) {
332 mem_types
[i
].prot_sect
&= ~PMD_BIT4
;
333 mem_types
[i
].prot_l1
&= ~PMD_BIT4
;
335 } else if (cpu_arch
< CPU_ARCH_ARMv6
) {
336 for (i
= 0; i
< ARRAY_SIZE(mem_types
); i
++) {
337 if (mem_types
[i
].prot_l1
)
338 mem_types
[i
].prot_l1
|= PMD_BIT4
;
339 if (mem_types
[i
].prot_sect
)
340 mem_types
[i
].prot_sect
|= PMD_BIT4
;
345 * Mark the device areas according to the CPU/architecture.
347 if (cpu_is_xsc3() || (cpu_arch
>= CPU_ARCH_ARMv6
&& (cr
& CR_XP
))) {
348 if (!cpu_is_xsc3()) {
350 * Mark device regions on ARMv6+ as execute-never
351 * to prevent speculative instruction fetches.
353 mem_types
[MT_DEVICE
].prot_sect
|= PMD_SECT_XN
;
354 mem_types
[MT_DEVICE_NONSHARED
].prot_sect
|= PMD_SECT_XN
;
355 mem_types
[MT_DEVICE_CACHED
].prot_sect
|= PMD_SECT_XN
;
356 mem_types
[MT_DEVICE_WC
].prot_sect
|= PMD_SECT_XN
;
358 if (cpu_arch
>= CPU_ARCH_ARMv7
&& (cr
& CR_TRE
)) {
360 * For ARMv7 with TEX remapping,
361 * - shared device is SXCB=1100
362 * - nonshared device is SXCB=0100
363 * - write combine device mem is SXCB=0001
364 * (Uncached Normal memory)
366 mem_types
[MT_DEVICE
].prot_sect
|= PMD_SECT_TEX(1);
367 mem_types
[MT_DEVICE_NONSHARED
].prot_sect
|= PMD_SECT_TEX(1);
368 mem_types
[MT_DEVICE_WC
].prot_sect
|= PMD_SECT_BUFFERABLE
;
369 } else if (cpu_is_xsc3()) {
372 * - shared device is TEXCB=00101
373 * - nonshared device is TEXCB=01000
374 * - write combine device mem is TEXCB=00100
375 * (Inner/Outer Uncacheable in xsc3 parlance)
377 mem_types
[MT_DEVICE
].prot_sect
|= PMD_SECT_TEX(1) | PMD_SECT_BUFFERED
;
378 mem_types
[MT_DEVICE_NONSHARED
].prot_sect
|= PMD_SECT_TEX(2);
379 mem_types
[MT_DEVICE_WC
].prot_sect
|= PMD_SECT_TEX(1);
382 * For ARMv6 and ARMv7 without TEX remapping,
383 * - shared device is TEXCB=00001
384 * - nonshared device is TEXCB=01000
385 * - write combine device mem is TEXCB=00100
386 * (Uncached Normal in ARMv6 parlance).
388 mem_types
[MT_DEVICE
].prot_sect
|= PMD_SECT_BUFFERED
;
389 mem_types
[MT_DEVICE_NONSHARED
].prot_sect
|= PMD_SECT_TEX(2);
390 mem_types
[MT_DEVICE_WC
].prot_sect
|= PMD_SECT_TEX(1);
394 * On others, write combining is "Uncached/Buffered"
396 mem_types
[MT_DEVICE_WC
].prot_sect
|= PMD_SECT_BUFFERABLE
;
400 * Now deal with the memory-type mappings
402 cp
= &cache_policies
[cachepolicy
];
403 vecs_pgprot
= kern_pgprot
= user_pgprot
= cp
->pte
;
406 * Only use write-through for non-SMP systems
408 if (!is_smp() && cpu_arch
>= CPU_ARCH_ARMv5
&& cachepolicy
> CPOLICY_WRITETHROUGH
)
409 vecs_pgprot
= cache_policies
[CPOLICY_WRITETHROUGH
].pte
;
412 * Enable CPU-specific coherency if supported.
413 * (Only available on XSC3 at the moment.)
415 if (arch_is_coherent() && cpu_is_xsc3()) {
416 mem_types
[MT_MEMORY
].prot_sect
|= PMD_SECT_S
;
417 mem_types
[MT_MEMORY
].prot_pte
|= L_PTE_SHARED
;
418 mem_types
[MT_MEMORY_NONCACHED
].prot_sect
|= PMD_SECT_S
;
419 mem_types
[MT_MEMORY_NONCACHED
].prot_pte
|= L_PTE_SHARED
;
422 * ARMv6 and above have extended page tables.
424 if (cpu_arch
>= CPU_ARCH_ARMv6
&& (cr
& CR_XP
)) {
426 * Mark cache clean areas and XIP ROM read only
427 * from SVC mode and no access from userspace.
429 mem_types
[MT_ROM
].prot_sect
|= PMD_SECT_APX
|PMD_SECT_AP_WRITE
;
430 mem_types
[MT_MINICLEAN
].prot_sect
|= PMD_SECT_APX
|PMD_SECT_AP_WRITE
;
431 mem_types
[MT_CACHECLEAN
].prot_sect
|= PMD_SECT_APX
|PMD_SECT_AP_WRITE
;
435 * Mark memory with the "shared" attribute
438 user_pgprot
|= L_PTE_SHARED
;
439 kern_pgprot
|= L_PTE_SHARED
;
440 vecs_pgprot
|= L_PTE_SHARED
;
441 mem_types
[MT_DEVICE_WC
].prot_sect
|= PMD_SECT_S
;
442 mem_types
[MT_DEVICE_WC
].prot_pte
|= L_PTE_SHARED
;
443 mem_types
[MT_DEVICE_CACHED
].prot_sect
|= PMD_SECT_S
;
444 mem_types
[MT_DEVICE_CACHED
].prot_pte
|= L_PTE_SHARED
;
445 mem_types
[MT_MEMORY
].prot_sect
|= PMD_SECT_S
;
446 mem_types
[MT_MEMORY
].prot_pte
|= L_PTE_SHARED
;
447 mem_types
[MT_MEMORY_NONCACHED
].prot_sect
|= PMD_SECT_S
;
448 mem_types
[MT_MEMORY_NONCACHED
].prot_pte
|= L_PTE_SHARED
;
453 * Non-cacheable Normal - intended for memory areas that must
454 * not cause dirty cache line writebacks when used
456 if (cpu_arch
>= CPU_ARCH_ARMv6
) {
457 if (cpu_arch
>= CPU_ARCH_ARMv7
&& (cr
& CR_TRE
)) {
458 /* Non-cacheable Normal is XCB = 001 */
459 mem_types
[MT_MEMORY_NONCACHED
].prot_sect
|=
462 /* For both ARMv6 and non-TEX-remapping ARMv7 */
463 mem_types
[MT_MEMORY_NONCACHED
].prot_sect
|=
467 mem_types
[MT_MEMORY_NONCACHED
].prot_sect
|= PMD_SECT_BUFFERABLE
;
470 for (i
= 0; i
< 16; i
++) {
471 unsigned long v
= pgprot_val(protection_map
[i
]);
472 protection_map
[i
] = __pgprot(v
| user_pgprot
);
475 mem_types
[MT_LOW_VECTORS
].prot_pte
|= vecs_pgprot
;
476 mem_types
[MT_HIGH_VECTORS
].prot_pte
|= vecs_pgprot
;
478 pgprot_user
= __pgprot(L_PTE_PRESENT
| L_PTE_YOUNG
| user_pgprot
);
479 pgprot_kernel
= __pgprot(L_PTE_PRESENT
| L_PTE_YOUNG
|
480 L_PTE_DIRTY
| kern_pgprot
);
482 mem_types
[MT_LOW_VECTORS
].prot_l1
|= ecc_mask
;
483 mem_types
[MT_HIGH_VECTORS
].prot_l1
|= ecc_mask
;
484 mem_types
[MT_MEMORY
].prot_sect
|= ecc_mask
| cp
->pmd
;
485 mem_types
[MT_MEMORY
].prot_pte
|= kern_pgprot
;
486 mem_types
[MT_MEMORY_NONCACHED
].prot_sect
|= ecc_mask
;
487 mem_types
[MT_ROM
].prot_sect
|= cp
->pmd
;
491 mem_types
[MT_CACHECLEAN
].prot_sect
|= PMD_SECT_WT
;
495 mem_types
[MT_CACHECLEAN
].prot_sect
|= PMD_SECT_WB
;
498 printk("Memory policy: ECC %sabled, Data cache %s\n",
499 ecc_mask
? "en" : "dis", cp
->policy
);
501 for (i
= 0; i
< ARRAY_SIZE(mem_types
); i
++) {
502 struct mem_type
*t
= &mem_types
[i
];
504 t
->prot_l1
|= PMD_DOMAIN(t
->domain
);
506 t
->prot_sect
|= PMD_DOMAIN(t
->domain
);
510 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
511 pgprot_t
phys_mem_access_prot(struct file
*file
, unsigned long pfn
,
512 unsigned long size
, pgprot_t vma_prot
)
515 return pgprot_noncached(vma_prot
);
516 else if (file
->f_flags
& O_SYNC
)
517 return pgprot_writecombine(vma_prot
);
520 EXPORT_SYMBOL(phys_mem_access_prot
);
523 #define vectors_base() (vectors_high() ? 0xffff0000 : 0)
525 static void __init
*early_alloc(unsigned long sz
)
527 void *ptr
= __va(memblock_alloc(sz
, sz
));
532 static pte_t
* __init
early_pte_alloc(pmd_t
*pmd
, unsigned long addr
, unsigned long prot
)
534 if (pmd_none(*pmd
)) {
535 pte_t
*pte
= early_alloc(PTE_HWTABLE_OFF
+ PTE_HWTABLE_SIZE
);
536 __pmd_populate(pmd
, __pa(pte
), prot
);
538 BUG_ON(pmd_bad(*pmd
));
539 return pte_offset_kernel(pmd
, addr
);
542 static void __init
alloc_init_pte(pmd_t
*pmd
, unsigned long addr
,
543 unsigned long end
, unsigned long pfn
,
544 const struct mem_type
*type
)
546 pte_t
*pte
= early_pte_alloc(pmd
, addr
, type
->prot_l1
);
548 set_pte_ext(pte
, pfn_pte(pfn
, __pgprot(type
->prot_pte
)), 0);
550 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
553 static void __init
alloc_init_section(pgd_t
*pgd
, unsigned long addr
,
554 unsigned long end
, phys_addr_t phys
,
555 const struct mem_type
*type
)
557 pmd_t
*pmd
= pmd_offset(pgd
, addr
);
560 * Try a section mapping - end, addr and phys must all be aligned
561 * to a section boundary. Note that PMDs refer to the individual
562 * L1 entries, whereas PGDs refer to a group of L1 entries making
563 * up one logical pointer to an L2 table.
565 if (((addr
| end
| phys
) & ~SECTION_MASK
) == 0) {
568 if (addr
& SECTION_SIZE
)
572 *pmd
= __pmd(phys
| type
->prot_sect
);
573 phys
+= SECTION_SIZE
;
574 } while (pmd
++, addr
+= SECTION_SIZE
, addr
!= end
);
579 * No need to loop; pte's aren't interested in the
580 * individual L1 entries.
582 alloc_init_pte(pmd
, addr
, end
, __phys_to_pfn(phys
), type
);
586 static void __init
create_36bit_mapping(struct map_desc
*md
,
587 const struct mem_type
*type
)
589 unsigned long addr
, length
, end
;
594 phys
= (unsigned long)__pfn_to_phys(md
->pfn
);
595 length
= PAGE_ALIGN(md
->length
);
597 if (!(cpu_architecture() >= CPU_ARCH_ARMv6
|| cpu_is_xsc3())) {
598 printk(KERN_ERR
"MM: CPU does not support supersection "
599 "mapping for 0x%08llx at 0x%08lx\n",
600 (long long)__pfn_to_phys((u64
)md
->pfn
), addr
);
604 /* N.B. ARMv6 supersections are only defined to work with domain 0.
605 * Since domain assignments can in fact be arbitrary, the
606 * 'domain == 0' check below is required to insure that ARMv6
607 * supersections are only allocated for domain 0 regardless
608 * of the actual domain assignments in use.
611 printk(KERN_ERR
"MM: invalid domain in supersection "
612 "mapping for 0x%08llx at 0x%08lx\n",
613 (long long)__pfn_to_phys((u64
)md
->pfn
), addr
);
617 if ((addr
| length
| __pfn_to_phys(md
->pfn
)) & ~SUPERSECTION_MASK
) {
618 printk(KERN_ERR
"MM: cannot create mapping for 0x%08llx"
619 " at 0x%08lx invalid alignment\n",
620 (long long)__pfn_to_phys((u64
)md
->pfn
), addr
);
625 * Shift bits [35:32] of address into bits [23:20] of PMD
628 phys
|= (((md
->pfn
>> (32 - PAGE_SHIFT
)) & 0xF) << 20);
630 pgd
= pgd_offset_k(addr
);
633 pmd_t
*pmd
= pmd_offset(pgd
, addr
);
636 for (i
= 0; i
< 16; i
++)
637 *pmd
++ = __pmd(phys
| type
->prot_sect
| PMD_SECT_SUPER
);
639 addr
+= SUPERSECTION_SIZE
;
640 phys
+= SUPERSECTION_SIZE
;
641 pgd
+= SUPERSECTION_SIZE
>> PGDIR_SHIFT
;
642 } while (addr
!= end
);
646 * Create the page directory entries and any necessary
647 * page tables for the mapping specified by `md'. We
648 * are able to cope here with varying sizes and address
649 * offsets, and we take full advantage of sections and
652 static void __init
create_mapping(struct map_desc
*md
)
654 unsigned long phys
, addr
, length
, end
;
655 const struct mem_type
*type
;
658 if (md
->virtual != vectors_base() && md
->virtual < TASK_SIZE
) {
659 printk(KERN_WARNING
"BUG: not creating mapping for 0x%08llx"
660 " at 0x%08lx in user region\n",
661 (long long)__pfn_to_phys((u64
)md
->pfn
), md
->virtual);
665 if ((md
->type
== MT_DEVICE
|| md
->type
== MT_ROM
) &&
666 md
->virtual >= PAGE_OFFSET
&& md
->virtual < VMALLOC_END
) {
667 printk(KERN_WARNING
"BUG: mapping for 0x%08llx"
668 " at 0x%08lx overlaps vmalloc space\n",
669 (long long)__pfn_to_phys((u64
)md
->pfn
), md
->virtual);
672 type
= &mem_types
[md
->type
];
675 * Catch 36-bit addresses
677 if (md
->pfn
>= 0x100000) {
678 create_36bit_mapping(md
, type
);
682 addr
= md
->virtual & PAGE_MASK
;
683 phys
= (unsigned long)__pfn_to_phys(md
->pfn
);
684 length
= PAGE_ALIGN(md
->length
+ (md
->virtual & ~PAGE_MASK
));
686 if (type
->prot_l1
== 0 && ((addr
| phys
| length
) & ~SECTION_MASK
)) {
687 printk(KERN_WARNING
"BUG: map for 0x%08llx at 0x%08lx can not "
688 "be mapped using pages, ignoring.\n",
689 (long long)__pfn_to_phys(md
->pfn
), addr
);
693 pgd
= pgd_offset_k(addr
);
696 unsigned long next
= pgd_addr_end(addr
, end
);
698 alloc_init_section(pgd
, addr
, next
, phys
, type
);
702 } while (pgd
++, addr
!= end
);
706 * Create the architecture specific mappings
708 void __init
iotable_init(struct map_desc
*io_desc
, int nr
)
712 for (i
= 0; i
< nr
; i
++)
713 create_mapping(io_desc
+ i
);
716 static void * __initdata vmalloc_min
= (void *)(VMALLOC_END
- SZ_128M
);
719 * vmalloc=size forces the vmalloc area to be exactly 'size'
720 * bytes. This can be used to increase (or decrease) the vmalloc
721 * area - the default is 128m.
723 static int __init
early_vmalloc(char *arg
)
725 unsigned long vmalloc_reserve
= memparse(arg
, NULL
);
727 if (vmalloc_reserve
< SZ_16M
) {
728 vmalloc_reserve
= SZ_16M
;
730 "vmalloc area too small, limiting to %luMB\n",
731 vmalloc_reserve
>> 20);
734 if (vmalloc_reserve
> VMALLOC_END
- (PAGE_OFFSET
+ SZ_32M
)) {
735 vmalloc_reserve
= VMALLOC_END
- (PAGE_OFFSET
+ SZ_32M
);
737 "vmalloc area is too big, limiting to %luMB\n",
738 vmalloc_reserve
>> 20);
741 vmalloc_min
= (void *)(VMALLOC_END
- vmalloc_reserve
);
744 early_param("vmalloc", early_vmalloc
);
746 static phys_addr_t lowmem_limit __initdata
= 0;
748 static void __init
sanity_check_meminfo(void)
750 int i
, j
, highmem
= 0;
752 lowmem_limit
= __pa(vmalloc_min
- 1) + 1;
753 memblock_set_current_limit(lowmem_limit
);
755 for (i
= 0, j
= 0; i
< meminfo
.nr_banks
; i
++) {
756 struct membank
*bank
= &meminfo
.bank
[j
];
757 *bank
= meminfo
.bank
[i
];
759 #ifdef CONFIG_HIGHMEM
760 if (__va(bank
->start
) > vmalloc_min
||
761 __va(bank
->start
) < (void *)PAGE_OFFSET
)
764 bank
->highmem
= highmem
;
767 * Split those memory banks which are partially overlapping
768 * the vmalloc area greatly simplifying things later.
770 if (__va(bank
->start
) < vmalloc_min
&&
771 bank
->size
> vmalloc_min
- __va(bank
->start
)) {
772 if (meminfo
.nr_banks
>= NR_BANKS
) {
773 printk(KERN_CRIT
"NR_BANKS too low, "
774 "ignoring high memory\n");
776 memmove(bank
+ 1, bank
,
777 (meminfo
.nr_banks
- i
) * sizeof(*bank
));
780 bank
[1].size
-= vmalloc_min
- __va(bank
->start
);
781 bank
[1].start
= __pa(vmalloc_min
- 1) + 1;
782 bank
[1].highmem
= highmem
= 1;
785 bank
->size
= vmalloc_min
- __va(bank
->start
);
788 bank
->highmem
= highmem
;
791 * Check whether this memory bank would entirely overlap
794 if (__va(bank
->start
) >= vmalloc_min
||
795 __va(bank
->start
) < (void *)PAGE_OFFSET
) {
796 printk(KERN_NOTICE
"Ignoring RAM at %.8lx-%.8lx "
797 "(vmalloc region overlap).\n",
798 bank
->start
, bank
->start
+ bank
->size
- 1);
803 * Check whether this memory bank would partially overlap
806 if (__va(bank
->start
+ bank
->size
) > vmalloc_min
||
807 __va(bank
->start
+ bank
->size
) < __va(bank
->start
)) {
808 unsigned long newsize
= vmalloc_min
- __va(bank
->start
);
809 printk(KERN_NOTICE
"Truncating RAM at %.8lx-%.8lx "
810 "to -%.8lx (vmalloc region overlap).\n",
811 bank
->start
, bank
->start
+ bank
->size
- 1,
812 bank
->start
+ newsize
- 1);
813 bank
->size
= newsize
;
818 #ifdef CONFIG_HIGHMEM
820 const char *reason
= NULL
;
822 if (cache_is_vipt_aliasing()) {
824 * Interactions between kmap and other mappings
825 * make highmem support with aliasing VIPT caches
828 reason
= "with VIPT aliasing cache";
829 } else if (is_smp() && tlb_ops_need_broadcast()) {
831 * kmap_high needs to occasionally flush TLB entries,
832 * however, if the TLB entries need to be broadcast
834 * kmap_high(irqs off)->flush_all_zero_pkmaps->
835 * flush_tlb_kernel_range->smp_call_function_many
836 * (must not be called with irqs off)
838 reason
= "without hardware TLB ops broadcasting";
841 printk(KERN_CRIT
"HIGHMEM is not supported %s, ignoring high memory\n",
843 while (j
> 0 && meminfo
.bank
[j
- 1].highmem
)
848 meminfo
.nr_banks
= j
;
851 static inline void prepare_page_table(void)
857 * Clear out all the mappings below the kernel image.
859 for (addr
= 0; addr
< MODULES_VADDR
; addr
+= PGDIR_SIZE
)
860 pmd_clear(pmd_off_k(addr
));
862 #ifdef CONFIG_XIP_KERNEL
863 /* The XIP kernel is mapped in the module area -- skip over it */
864 addr
= ((unsigned long)_etext
+ PGDIR_SIZE
- 1) & PGDIR_MASK
;
866 for ( ; addr
< PAGE_OFFSET
; addr
+= PGDIR_SIZE
)
867 pmd_clear(pmd_off_k(addr
));
870 * Find the end of the first block of lowmem.
872 end
= memblock
.memory
.regions
[0].base
+ memblock
.memory
.regions
[0].size
;
873 if (end
>= lowmem_limit
)
877 * Clear out all the kernel space mappings, except for the first
878 * memory bank, up to the end of the vmalloc region.
880 for (addr
= __phys_to_virt(end
);
881 addr
< VMALLOC_END
; addr
+= PGDIR_SIZE
)
882 pmd_clear(pmd_off_k(addr
));
886 * Reserve the special regions of memory
888 void __init
arm_mm_memblock_reserve(void)
891 * Reserve the page tables. These are already in use,
892 * and can only be in node 0.
894 memblock_reserve(__pa(swapper_pg_dir
), PTRS_PER_PGD
* sizeof(pgd_t
));
898 * Because of the SA1111 DMA bug, we want to preserve our
899 * precious DMA-able memory...
901 memblock_reserve(PHYS_OFFSET
, __pa(swapper_pg_dir
) - PHYS_OFFSET
);
906 * Set up device the mappings. Since we clear out the page tables for all
907 * mappings above VMALLOC_END, we will remove any debug device mappings.
908 * This means you have to be careful how you debug this function, or any
909 * called function. This means you can't use any function or debugging
910 * method which may touch any device, otherwise the kernel _will_ crash.
912 static void __init
devicemaps_init(struct machine_desc
*mdesc
)
919 * Allocate the vector page early.
921 vectors
= early_alloc(PAGE_SIZE
);
923 for (addr
= VMALLOC_END
; addr
; addr
+= PGDIR_SIZE
)
924 pmd_clear(pmd_off_k(addr
));
927 * Map the kernel if it is XIP.
928 * It is always first in the modulearea.
930 #ifdef CONFIG_XIP_KERNEL
931 map
.pfn
= __phys_to_pfn(CONFIG_XIP_PHYS_ADDR
& SECTION_MASK
);
932 map
.virtual = MODULES_VADDR
;
933 map
.length
= ((unsigned long)_etext
- map
.virtual + ~SECTION_MASK
) & SECTION_MASK
;
935 create_mapping(&map
);
939 * Map the cache flushing regions.
942 map
.pfn
= __phys_to_pfn(FLUSH_BASE_PHYS
);
943 map
.virtual = FLUSH_BASE
;
945 map
.type
= MT_CACHECLEAN
;
946 create_mapping(&map
);
948 #ifdef FLUSH_BASE_MINICACHE
949 map
.pfn
= __phys_to_pfn(FLUSH_BASE_PHYS
+ SZ_1M
);
950 map
.virtual = FLUSH_BASE_MINICACHE
;
952 map
.type
= MT_MINICLEAN
;
953 create_mapping(&map
);
957 * Create a mapping for the machine vectors at the high-vectors
958 * location (0xffff0000). If we aren't using high-vectors, also
959 * create a mapping at the low-vectors virtual address.
961 map
.pfn
= __phys_to_pfn(virt_to_phys(vectors
));
962 map
.virtual = 0xffff0000;
963 map
.length
= PAGE_SIZE
;
964 map
.type
= MT_HIGH_VECTORS
;
965 create_mapping(&map
);
967 if (!vectors_high()) {
969 map
.type
= MT_LOW_VECTORS
;
970 create_mapping(&map
);
974 * Ask the machine support to map in the statically mapped devices.
980 * Finally flush the caches and tlb to ensure that we're in a
981 * consistent state wrt the writebuffer. This also ensures that
982 * any write-allocated cache lines in the vector page are written
983 * back. After this point, we can start to touch devices again.
985 local_flush_tlb_all();
989 static void __init
kmap_init(void)
991 #ifdef CONFIG_HIGHMEM
992 pkmap_page_table
= early_pte_alloc(pmd_off_k(PKMAP_BASE
),
993 PKMAP_BASE
, _PAGE_KERNEL_TABLE
);
997 static void __init
map_lowmem(void)
999 struct memblock_region
*reg
;
1001 /* Map all the lowmem memory banks. */
1002 for_each_memblock(memory
, reg
) {
1003 phys_addr_t start
= reg
->base
;
1004 phys_addr_t end
= start
+ reg
->size
;
1005 struct map_desc map
;
1007 if (end
> lowmem_limit
)
1012 map
.pfn
= __phys_to_pfn(start
);
1013 map
.virtual = __phys_to_virt(start
);
1014 map
.length
= end
- start
;
1015 map
.type
= MT_MEMORY
;
1017 create_mapping(&map
);
1022 * paging_init() sets up the page tables, initialises the zone memory
1023 * maps, and sets up the zero page, bad page and bad page tables.
1025 void __init
paging_init(struct machine_desc
*mdesc
)
1029 build_mem_type_table();
1030 sanity_check_meminfo();
1031 prepare_page_table();
1033 devicemaps_init(mdesc
);
1036 top_pmd
= pmd_off_k(0xffff0000);
1038 /* allocate the zero page. */
1039 zero_page
= early_alloc(PAGE_SIZE
);
1043 empty_zero_page
= virt_to_page(zero_page
);
1044 __flush_dcache_page(NULL
, empty_zero_page
);