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gerrit-public.fairphone.software / kernel / msm / 0b9db08ba8397f3e21371f56dd1ecac2d8ef4a1c / . / arch / arm / mm / mmu.c
blob: a1a2e51e69f5c4b62244dc60e68937079863eaed [file] [log] [blame]
/*
* linux/arch/arm/mm/mmu.c
*
* Copyright (C) 1995-2005 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/memblock.h>
#include <linux/fs.h>
#include <linux/vmalloc.h>
#include <asm/cp15.h>
#include <asm/cputype.h>
#include <asm/sections.h>
#include <asm/cachetype.h>
#include <asm/setup.h>
#include <asm/sizes.h>
#include <asm/smp_plat.h>
#include <asm/tlb.h>
#include <asm/highmem.h>
#include <asm/system_info.h>
#include <asm/traps.h>
#include <asm/mmu_writeable.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <asm/user_accessible_timer.h>
#include "mm.h"
/*
* empty_zero_page is a special page that is used for
* zero-initialized data and COW.
*/
struct page *empty_zero_page;
EXPORT_SYMBOL(empty_zero_page);
/*
* The pmd table for the upper-most set of pages.
*/
pmd_t *top_pmd;
#define CPOLICY_UNCACHED 0
#define CPOLICY_BUFFERED 1
#define CPOLICY_WRITETHROUGH 2
#define CPOLICY_WRITEBACK 3
#define CPOLICY_WRITEALLOC 4
#define RX_AREA_START _text
#define RX_AREA_END __start_rodata
static unsigned int cachepolicy __initdata = CPOLICY_WRITEBACK;
static unsigned int ecc_mask __initdata = 0;
pgprot_t pgprot_user;
pgprot_t pgprot_kernel;
EXPORT_SYMBOL(pgprot_user);
EXPORT_SYMBOL(pgprot_kernel);
struct cachepolicy {
const char policy[16];
unsigned int cr_mask;
pmdval_t pmd;
pteval_t pte;
};
static struct cachepolicy cache_policies[] __initdata = {
{
.policy = "uncached",
.cr_mask = CR_W|CR_C,
.pmd = PMD_SECT_UNCACHED,
.pte = L_PTE_MT_UNCACHED,
}, {
.policy = "buffered",
.cr_mask = CR_C,
.pmd = PMD_SECT_BUFFERED,
.pte = L_PTE_MT_BUFFERABLE,
}, {
.policy = "writethrough",
.cr_mask = 0,
.pmd = PMD_SECT_WT,
.pte = L_PTE_MT_WRITETHROUGH,
}, {
.policy = "writeback",
.cr_mask = 0,
.pmd = PMD_SECT_WB,
.pte = L_PTE_MT_WRITEBACK,
}, {
.policy = "writealloc",
.cr_mask = 0,
.pmd = PMD_SECT_WBWA,
.pte = L_PTE_MT_WRITEALLOC,
}
};
/*
* These are useful for identifying cache coherency
* problems by allowing the cache or the cache and
* writebuffer to be turned off. (Note: the write
* buffer should not be on and the cache off).
*/
static int __init early_cachepolicy(char *p)
{
int i;
for (i = 0; i < ARRAY_SIZE(cache_policies); i++) {
int len = strlen(cache_policies[i].policy);
if (memcmp(p, cache_policies[i].policy, len) == 0) {
cachepolicy = i;
cr_alignment &= ~cache_policies[i].cr_mask;
cr_no_alignment &= ~cache_policies[i].cr_mask;
break;
}
}
if (i == ARRAY_SIZE(cache_policies))
printk(KERN_ERR "ERROR: unknown or unsupported cache policy\n");
/*
* This restriction is partly to do with the way we boot; it is
* unpredictable to have memory mapped using two different sets of
* memory attributes (shared, type, and cache attribs). We can not
* change these attributes once the initial assembly has setup the
* page tables.
*/
if (cpu_architecture() >= CPU_ARCH_ARMv6) {
printk(KERN_WARNING "Only cachepolicy=writeback supported on ARMv6 and later\n");
cachepolicy = CPOLICY_WRITEBACK;
}
flush_cache_all();
set_cr(cr_alignment);
return 0;
}
early_param("cachepolicy", early_cachepolicy);
static int __init early_nocache(char *__unused)
{
char *p = "buffered";
printk(KERN_WARNING "nocache is deprecated; use cachepolicy=%s\n", p);
early_cachepolicy(p);
return 0;
}
early_param("nocache", early_nocache);
static int __init early_nowrite(char *__unused)
{
char *p = "uncached";
printk(KERN_WARNING "nowb is deprecated; use cachepolicy=%s\n", p);
early_cachepolicy(p);
return 0;
}
early_param("nowb", early_nowrite);
#ifndef CONFIG_ARM_LPAE
static int __init early_ecc(char *p)
{
if (memcmp(p, "on", 2) == 0)
ecc_mask = PMD_PROTECTION;
else if (memcmp(p, "off", 3) == 0)
ecc_mask = 0;
return 0;
}
early_param("ecc", early_ecc);
#endif
static int __init noalign_setup(char *__unused)
{
cr_alignment &= ~CR_A;
cr_no_alignment &= ~CR_A;
set_cr(cr_alignment);
return 1;
}
__setup("noalign", noalign_setup);
#ifndef CONFIG_SMP
void adjust_cr(unsigned long mask, unsigned long set)
{
unsigned long flags;
mask &= ~CR_A;
set &= mask;
local_irq_save(flags);
cr_no_alignment = (cr_no_alignment & ~mask) | set;
cr_alignment = (cr_alignment & ~mask) | set;
set_cr((get_cr() & ~mask) | set);
local_irq_restore(flags);
}
#endif
#define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN
#define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE
static struct mem_type mem_types[] = {
[MT_DEVICE] = { /* Strongly ordered / ARMv6 shared device */
.prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_SHARED |
L_PTE_SHARED,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PROT_SECT_DEVICE | PMD_SECT_S,
.domain = DOMAIN_IO,
},
[MT_DEVICE_NONSHARED] = { /* ARMv6 non-shared device */
.prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_NONSHARED,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PROT_SECT_DEVICE,
.domain = DOMAIN_IO,
},
[MT_DEVICE_CACHED] = { /* ioremap_cached */
.prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_CACHED,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PROT_SECT_DEVICE | PMD_SECT_WB,
.domain = DOMAIN_IO,
},
[MT_DEVICE_WC] = { /* ioremap_wc */
.prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_WC,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PROT_SECT_DEVICE,
.domain = DOMAIN_IO,
},
[MT_UNCACHED] = {
.prot_pte = PROT_PTE_DEVICE,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
.domain = DOMAIN_IO,
},
[MT_CACHECLEAN] = {
.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
.domain = DOMAIN_KERNEL,
},
#ifndef CONFIG_ARM_LPAE
[MT_MINICLEAN] = {
.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_MINICACHE,
.domain = DOMAIN_KERNEL,
},
#endif
[MT_LOW_VECTORS] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_RDONLY,
.prot_l1 = PMD_TYPE_TABLE,
.domain = DOMAIN_USER,
},
[MT_HIGH_VECTORS] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_USER | L_PTE_RDONLY,
.prot_l1 = PMD_TYPE_TABLE,
.domain = DOMAIN_USER,
},
[MT_MEMORY] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_R] = {
.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_RW] = {
.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_XN,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_RX] = {
.prot_sect = PMD_TYPE_SECT,
.domain = DOMAIN_KERNEL,
},
[MT_ROM] = {
.prot_sect = PMD_TYPE_SECT,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_NONCACHED] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_MT_BUFFERABLE,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_DTCM] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_XN,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_ITCM] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
.prot_l1 = PMD_TYPE_TABLE,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_SO] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_MT_UNCACHED,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_S |
PMD_SECT_UNCACHED | PMD_SECT_XN,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_DMA_READY] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
.prot_l1 = PMD_TYPE_TABLE,
.domain = DOMAIN_KERNEL,
},
[MT_DEVICE_USER_ACCESSIBLE] = {
.prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_SHARED |
L_PTE_SHARED | L_PTE_USER | L_PTE_RDONLY,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PROT_SECT_DEVICE | PMD_SECT_S,
.domain = DOMAIN_IO,
},
};
const struct mem_type *get_mem_type(unsigned int type)
{
return type < ARRAY_SIZE(mem_types) ? &mem_types[type] : NULL;
}
EXPORT_SYMBOL(get_mem_type);
#define PTE_SET_FN(_name, pteop) \
static int pte_set_##_name(pte_t *ptep, pgtable_t token, unsigned long addr, \
void *data) \
{ \
pte_t pte = pteop(*ptep); \
\
set_pte_ext(ptep, pte, 0); \
return 0; \
} \
#define SET_MEMORY_FN(_name, callback) \
int set_memory_##_name(unsigned long addr, int numpages) \
{ \
unsigned long start = addr; \
unsigned long size = PAGE_SIZE*numpages; \
unsigned end = start + size; \
\
if (start < MODULES_VADDR || start >= MODULES_END) \
return -EINVAL;\
\
if (end < MODULES_VADDR || end >= MODULES_END) \
return -EINVAL; \
\
apply_to_page_range(&init_mm, start, size, callback, NULL); \
flush_tlb_kernel_range(start, end); \
return 0;\
}
PTE_SET_FN(ro, pte_wrprotect)
PTE_SET_FN(rw, pte_mkwrite)
PTE_SET_FN(x, pte_mkexec)
PTE_SET_FN(nx, pte_mknexec)
SET_MEMORY_FN(ro, pte_set_ro)
EXPORT_SYMBOL(set_memory_ro);
SET_MEMORY_FN(rw, pte_set_rw)
EXPORT_SYMBOL(set_memory_rw);
SET_MEMORY_FN(x, pte_set_x)
EXPORT_SYMBOL(set_memory_x);
SET_MEMORY_FN(nx, pte_set_nx)
EXPORT_SYMBOL(set_memory_nx);
/*
* Adjust the PMD section entries according to the CPU in use.
*/
static void __init build_mem_type_table(void)
{
struct cachepolicy *cp;
unsigned int cr = get_cr();
pteval_t user_pgprot, kern_pgprot, vecs_pgprot;
int cpu_arch = cpu_architecture();
int i;
if (cpu_arch < CPU_ARCH_ARMv6) {
#if defined(CONFIG_CPU_DCACHE_DISABLE)
if (cachepolicy > CPOLICY_BUFFERED)
cachepolicy = CPOLICY_BUFFERED;
#elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH)
if (cachepolicy > CPOLICY_WRITETHROUGH)
cachepolicy = CPOLICY_WRITETHROUGH;
#endif
}
if (cpu_arch < CPU_ARCH_ARMv5) {
if (cachepolicy >= CPOLICY_WRITEALLOC)
cachepolicy = CPOLICY_WRITEBACK;
ecc_mask = 0;
}
if (is_smp())
cachepolicy = CPOLICY_WRITEALLOC;
/*
* Strip out features not present on earlier architectures.
* Pre-ARMv5 CPUs don't have TEX bits. Pre-ARMv6 CPUs or those
* without extended page tables don't have the 'Shared' bit.
*/
if (cpu_arch < CPU_ARCH_ARMv5)
for (i = 0; i < ARRAY_SIZE(mem_types); i++)
mem_types[i].prot_sect &= ~PMD_SECT_TEX(7);
if ((cpu_arch < CPU_ARCH_ARMv6 || !(cr & CR_XP)) && !cpu_is_xsc3())
for (i = 0; i < ARRAY_SIZE(mem_types); i++)
mem_types[i].prot_sect &= ~PMD_SECT_S;
/*
* ARMv5 and lower, bit 4 must be set for page tables (was: cache
* "update-able on write" bit on ARM610). However, Xscale and
* Xscale3 require this bit to be cleared.
*/
if (cpu_is_xscale() || cpu_is_xsc3()) {
for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
mem_types[i].prot_sect &= ~PMD_BIT4;
mem_types[i].prot_l1 &= ~PMD_BIT4;
}
} else if (cpu_arch < CPU_ARCH_ARMv6) {
for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
if (mem_types[i].prot_l1)
mem_types[i].prot_l1 |= PMD_BIT4;
if (mem_types[i].prot_sect)
mem_types[i].prot_sect |= PMD_BIT4;
}
}
/*
* Mark the device areas according to the CPU/architecture.
*/
if (cpu_is_xsc3() || (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP))) {
if (!cpu_is_xsc3()) {
/*
* Mark device regions on ARMv6+ as execute-never
* to prevent speculative instruction fetches.
*/
mem_types[MT_DEVICE].prot_sect |= PMD_SECT_XN;
mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_XN;
mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_XN;
mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_XN;
}
if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) {
/*
* For ARMv7 with TEX remapping,
* - shared device is SXCB=1100
* - nonshared device is SXCB=0100
* - write combine device mem is SXCB=0001
* (Uncached Normal memory)
*/
mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1);
mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(1);
mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
} else if (cpu_is_xsc3()) {
/*
* For Xscale3,
* - shared device is TEXCB=00101
* - nonshared device is TEXCB=01000
* - write combine device mem is TEXCB=00100
* (Inner/Outer Uncacheable in xsc3 parlance)
*/
mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1) | PMD_SECT_BUFFERED;
mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2);
mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
} else {
/*
* For ARMv6 and ARMv7 without TEX remapping,
* - shared device is TEXCB=00001
* - nonshared device is TEXCB=01000
* - write combine device mem is TEXCB=00100
* (Uncached Normal in ARMv6 parlance).
*/
mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED;
mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2);
mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
}
} else {
/*
* On others, write combining is "Uncached/Buffered"
*/
mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
}
/*
* Now deal with the memory-type mappings
*/
cp = &cache_policies[cachepolicy];
vecs_pgprot = kern_pgprot = user_pgprot = cp->pte;
/*
* Only use write-through for non-SMP systems
*/
if (!is_smp() && cpu_arch >= CPU_ARCH_ARMv5 && cachepolicy > CPOLICY_WRITETHROUGH)
vecs_pgprot = cache_policies[CPOLICY_WRITETHROUGH].pte;
/*
* Enable CPU-specific coherency if supported.
* (Only available on XSC3 at the moment.)
*/
if (arch_is_coherent() && cpu_is_xsc3()) {
mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED;
mem_types[MT_MEMORY_DMA_READY].prot_pte |= L_PTE_SHARED;
mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY_NONCACHED].prot_pte |= L_PTE_SHARED;
}
/*
* ARMv6 and above have extended page tables.
*/
if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) {
#ifndef CONFIG_ARM_LPAE
/*
* Mark cache clean areas and XIP ROM read only
* from SVC mode and no access from userspace.
*/
mem_types[MT_ROM].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
mem_types[MT_MEMORY_RX].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
mem_types[MT_MEMORY_R].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
#endif
if (is_smp()) {
/*
* Mark memory with the "shared" attribute
* for SMP systems
*/
user_pgprot |= L_PTE_SHARED;
kern_pgprot |= L_PTE_SHARED;
vecs_pgprot |= L_PTE_SHARED;
mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_S;
mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_SHARED;
mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_S;
mem_types[MT_DEVICE_CACHED].prot_pte |= L_PTE_SHARED;
mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED;
mem_types[MT_MEMORY_DMA_READY].prot_pte |= L_PTE_SHARED;
mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY_R].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY_RW].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY_RX].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY_NONCACHED].prot_pte |= L_PTE_SHARED;
}
}
/*
* Non-cacheable Normal - intended for memory areas that must
* not cause dirty cache line writebacks when used
*/
if (cpu_arch >= CPU_ARCH_ARMv6) {
if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) {
/* Non-cacheable Normal is XCB = 001 */
mem_types[MT_MEMORY_NONCACHED].prot_sect |=
PMD_SECT_BUFFERED;
} else {
/* For both ARMv6 and non-TEX-remapping ARMv7 */
mem_types[MT_MEMORY_NONCACHED].prot_sect |=
PMD_SECT_TEX(1);
}
} else {
mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_BUFFERABLE;
}
#ifdef CONFIG_ARM_LPAE
/*
* Do not generate access flag faults for the kernel mappings.
*/
for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
mem_types[i].prot_pte |= PTE_EXT_AF;
if (mem_types[i].prot_sect)
mem_types[i].prot_sect |= PMD_SECT_AF;
}
kern_pgprot |= PTE_EXT_AF;
vecs_pgprot |= PTE_EXT_AF;
#endif
for (i = 0; i < 16; i++) {
unsigned long v = pgprot_val(protection_map[i]);
protection_map[i] = __pgprot(v | user_pgprot);
}
mem_types[MT_LOW_VECTORS].prot_pte |= vecs_pgprot;
mem_types[MT_HIGH_VECTORS].prot_pte |= vecs_pgprot;
pgprot_user = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | user_pgprot);
pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
L_PTE_DIRTY | kern_pgprot);
mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;
mem_types[MT_MEMORY].prot_sect |= ecc_mask | cp->pmd;
mem_types[MT_MEMORY].prot_pte |= kern_pgprot;
mem_types[MT_MEMORY_DMA_READY].prot_pte |= kern_pgprot;
mem_types[MT_MEMORY_NONCACHED].prot_sect |= ecc_mask;
mem_types[MT_MEMORY_R].prot_sect |= ecc_mask | cp->pmd;
mem_types[MT_MEMORY_RW].prot_sect |= ecc_mask | cp->pmd;
mem_types[MT_MEMORY_RX].prot_sect |= ecc_mask | cp->pmd;
mem_types[MT_ROM].prot_sect |= cp->pmd;
switch (cp->pmd) {
case PMD_SECT_WT:
mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WT;
break;
case PMD_SECT_WB:
case PMD_SECT_WBWA:
mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WB;
break;
}
printk("Memory policy: ECC %sabled, Data cache %s\n",
ecc_mask ? "en" : "dis", cp->policy);
for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
struct mem_type *t = &mem_types[i];
if (t->prot_l1)
t->prot_l1 |= PMD_DOMAIN(t->domain);
if (t->prot_sect)
t->prot_sect |= PMD_DOMAIN(t->domain);
}
}
#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
{
if (!pfn_valid(pfn))
return pgprot_noncached(vma_prot);
else if (file->f_flags & O_SYNC)
return pgprot_writecombine(vma_prot);
return vma_prot;
}
EXPORT_SYMBOL(phys_mem_access_prot);
#endif
#define vectors_base() (vectors_high() ? 0xffff0000 : 0)
static void __init *early_alloc_aligned(unsigned long sz, unsigned long align)
{
void *ptr = __va(memblock_alloc(sz, align));
memset(ptr, 0, sz);
return ptr;
}
static void __init *early_alloc(unsigned long sz)
{
return early_alloc_aligned(sz, sz);
}
static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr, unsigned long prot)
{
if (pmd_none(*pmd)) {
pte_t *pte = early_alloc(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE);
__pmd_populate(pmd, __pa(pte), prot);
}
BUG_ON(pmd_bad(*pmd));
return pte_offset_kernel(pmd, addr);
}
static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr,
unsigned long end, unsigned long pfn,
const struct mem_type *type)
{
pte_t *pte = early_pte_alloc(pmd, addr, type->prot_l1);
do {
set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)), 0);
pfn++;
} while (pte++, addr += PAGE_SIZE, addr != end);
}
static void __init map_init_section(pmd_t *pmd, unsigned long addr,
unsigned long end, phys_addr_t phys,
const struct mem_type *type)
{
#ifndef CONFIG_ARM_LPAE
/*
* In classic MMU format, puds and pmds are folded in to
* the pgds. pmd_offset gives the PGD entry. PGDs refer to a
* group of L1 entries making up one logical pointer to
* an L2 table (2MB), where as PMDs refer to the individual
* L1 entries (1MB). Hence increment to get the correct
* offset for odd 1MB sections.
* (See arch/arm/include/asm/pgtable-2level.h)
*/
if (addr & SECTION_SIZE)
pmd++;
#endif
do {
*pmd = __pmd(phys | type->prot_sect);
phys += SECTION_SIZE;
} while (pmd++, addr += SECTION_SIZE, addr != end);
flush_pmd_entry(pmd);
}
static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
unsigned long end, phys_addr_t phys,
const struct mem_type *type)
{
pmd_t *pmd = pmd_offset(pud, addr);
unsigned long next;
do {
/*
* With LPAE, we must loop over to map
* all the pmds for the given range.
*/
next = pmd_addr_end(addr, end);
/*
* Try a section mapping - addr, next and phys must all be
* aligned to a section boundary.
*/
if (type->prot_sect &&
((addr | next | phys) & ~SECTION_MASK) == 0) {
map_init_section(pmd, addr, next, phys, type);
} else {
alloc_init_pte(pmd, addr, next,
__phys_to_pfn(phys), type);
}
phys += next - addr;
} while (pmd++, addr = next, addr != end);
}
static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
unsigned long end, unsigned long phys, const struct mem_type *type)
{
pud_t *pud = pud_offset(pgd, addr);
unsigned long next;
do {
next = pud_addr_end(addr, end);
alloc_init_pmd(pud, addr, next, phys, type);
phys += next - addr;
} while (pud++, addr = next, addr != end);
}
#ifndef CONFIG_ARM_LPAE
static void __init create_36bit_mapping(struct map_desc *md,
const struct mem_type *type)
{
unsigned long addr, length, end;
phys_addr_t phys;
pgd_t *pgd;
addr = md->virtual;
phys = __pfn_to_phys(md->pfn);
length = PAGE_ALIGN(md->length);
if (!(cpu_architecture() >= CPU_ARCH_ARMv6 || cpu_is_xsc3())) {
printk(KERN_ERR "MM: CPU does not support supersection "
"mapping for 0x%08llx at 0x%08lx\n",
(long long)__pfn_to_phys((u64)md->pfn), addr);
return;
}
/* N.B. ARMv6 supersections are only defined to work with domain 0.
* Since domain assignments can in fact be arbitrary, the
* 'domain == 0' check below is required to insure that ARMv6
* supersections are only allocated for domain 0 regardless
* of the actual domain assignments in use.
*/
if (type->domain) {
printk(KERN_ERR "MM: invalid domain in supersection "
"mapping for 0x%08llx at 0x%08lx\n",
(long long)__pfn_to_phys((u64)md->pfn), addr);
return;
}
if ((addr | length | __pfn_to_phys(md->pfn)) & ~SUPERSECTION_MASK) {
printk(KERN_ERR "MM: cannot create mapping for 0x%08llx"
" at 0x%08lx invalid alignment\n",
(long long)__pfn_to_phys((u64)md->pfn), addr);
return;
}
/*
* Shift bits [35:32] of address into bits [23:20] of PMD
* (See ARMv6 spec).
*/
phys |= (((md->pfn >> (32 - PAGE_SHIFT)) & 0xF) << 20);
pgd = pgd_offset_k(addr);
end = addr + length;
do {
pud_t *pud = pud_offset(pgd, addr);
pmd_t *pmd = pmd_offset(pud, addr);
int i;
for (i = 0; i < 16; i++)
*pmd++ = __pmd(phys | type->prot_sect | PMD_SECT_SUPER);
addr += SUPERSECTION_SIZE;
phys += SUPERSECTION_SIZE;
pgd += SUPERSECTION_SIZE >> PGDIR_SHIFT;
} while (addr != end);
}
#endif /* !CONFIG_ARM_LPAE */
/*
* Create the page directory entries and any necessary
* page tables for the mapping specified by `md'. We
* are able to cope here with varying sizes and address
* offsets, and we take full advantage of sections and
* supersections.
*/
static void __init create_mapping(struct map_desc *md)
{
unsigned long addr, length, end;
phys_addr_t phys;
const struct mem_type *type;
pgd_t *pgd;
if ((md->virtual != vectors_base() &&
md->virtual != get_user_accessible_timers_base()) &&
md->virtual < TASK_SIZE) {
printk(KERN_WARNING "BUG: not creating mapping for 0x%08llx"
" at 0x%08lx in user region\n",
(long long)__pfn_to_phys((u64)md->pfn), md->virtual);
return;
}
if ((md->type == MT_DEVICE || md->type == MT_ROM) &&
md->virtual >= PAGE_OFFSET &&
(md->virtual < VMALLOC_START || md->virtual >= VMALLOC_END)) {
printk(KERN_WARNING "BUG: mapping for 0x%08llx"
" at 0x%08lx out of vmalloc space\n",
(long long)__pfn_to_phys((u64)md->pfn), md->virtual);
}
type = &mem_types[md->type];
#ifndef CONFIG_ARM_LPAE
/*
* Catch 36-bit addresses
*/
if (md->pfn >= 0x100000) {
create_36bit_mapping(md, type);
return;
}
#endif
addr = md->virtual & PAGE_MASK;
phys = __pfn_to_phys(md->pfn);
length = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
if (type->prot_l1 == 0 && ((addr | phys | length) & ~SECTION_MASK)) {
printk(KERN_WARNING "BUG: map for 0x%08llx at 0x%08lx can not "
"be mapped using pages, ignoring.\n",
(long long)__pfn_to_phys(md->pfn), addr);
return;
}
pgd = pgd_offset_k(addr);
end = addr + length;
do {
unsigned long next = pgd_addr_end(addr, end);
alloc_init_pud(pgd, addr, next, phys, type);
phys += next - addr;
addr = next;
} while (pgd++, addr != end);
}
/*
* Create the architecture specific mappings
*/
void __init iotable_init(struct map_desc *io_desc, int nr)
{
struct map_desc *md;
struct vm_struct *vm;
int rc = 0;
if (!nr)
return;
vm = early_alloc_aligned(sizeof(*vm) * nr, __alignof__(*vm));
for (md = io_desc; nr; md++, nr--) {
create_mapping(md);
vm->addr = (void *)(md->virtual & PAGE_MASK);
vm->size = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
vm->phys_addr = __pfn_to_phys(md->pfn);
vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
vm->flags |= VM_ARM_MTYPE(md->type);
vm->caller = iotable_init;
rc = vm_area_check_early(vm);
if (!rc)
vm_area_add_early(vm++);
}
}
#ifndef CONFIG_ARM_LPAE
/*
* The Linux PMD is made of two consecutive section entries covering 2MB
* (see definition in include/asm/pgtable-2level.h). However a call to
* create_mapping() may optimize static mappings by using individual
* 1MB section mappings. This leaves the actual PMD potentially half
* initialized if the top or bottom section entry isn't used, leaving it
* open to problems if a subsequent ioremap() or vmalloc() tries to use
* the virtual space left free by that unused section entry.
*
* Let's avoid the issue by inserting dummy vm entries covering the unused
* PMD halves once the static mappings are in place.
*/
static void __init pmd_empty_section_gap(unsigned long addr)
{
struct vm_struct *vm;
vm = early_alloc_aligned(sizeof(*vm), __alignof__(*vm));
vm->addr = (void *)addr;
vm->size = SECTION_SIZE;
vm->flags = VM_IOREMAP | VM_ARM_EMPTY_MAPPING;
vm->caller = pmd_empty_section_gap;
vm_area_add_early(vm);
}
static void __init fill_pmd_gaps(void)
{
struct vm_struct *vm;
unsigned long addr, next = 0;
pmd_t *pmd;
/* we're still single threaded hence no lock needed here */
for (vm = vmlist; vm; vm = vm->next) {
if (!(vm->flags & (VM_ARM_STATIC_MAPPING | VM_ARM_EMPTY_MAPPING)))
continue;
addr = (unsigned long)vm->addr;
if (addr < next)
continue;
/*
* Check if this vm starts on an odd section boundary.
* If so and the first section entry for this PMD is free
* then we block the corresponding virtual address.
*/
if ((addr & ~PMD_MASK) == SECTION_SIZE) {
pmd = pmd_off_k(addr);
if (pmd_none(*pmd))
pmd_empty_section_gap(addr & PMD_MASK);
}
/*
* Then check if this vm ends on an odd section boundary.
* If so and the second section entry for this PMD is empty
* then we block the corresponding virtual address.
*/
addr += vm->size;
if ((addr & ~PMD_MASK) == SECTION_SIZE) {
pmd = pmd_off_k(addr) + 1;
if (pmd_none(*pmd))
pmd_empty_section_gap(addr);
}
/* no need to look at any vm entry until we hit the next PMD */
next = (addr + PMD_SIZE - 1) & PMD_MASK;
}
}
#else
#define fill_pmd_gaps() do { } while (0)
#endif
static void * __initdata vmalloc_min =
(void *)(VMALLOC_END - (240 << 20) - VMALLOC_OFFSET);
/*
* vmalloc=size forces the vmalloc area to be exactly 'size'
* bytes. This can be used to increase (or decrease) the vmalloc
* area - the default is 240m.
*/
static int __init early_vmalloc(char *arg)
{
unsigned long vmalloc_reserve = memparse(arg, NULL);
if (vmalloc_reserve < SZ_16M) {
vmalloc_reserve = SZ_16M;
printk(KERN_WARNING
"vmalloc area too small, limiting to %luMB\n",
vmalloc_reserve >> 20);
}
if (vmalloc_reserve > VMALLOC_END - (PAGE_OFFSET + SZ_32M)) {
vmalloc_reserve = VMALLOC_END - (PAGE_OFFSET + SZ_32M);
printk(KERN_WARNING
"vmalloc area is too big, limiting to %luMB\n",
vmalloc_reserve >> 20);
}
vmalloc_min = (void *)(VMALLOC_END - vmalloc_reserve);
return 0;
}
early_param("vmalloc", early_vmalloc);
phys_addr_t arm_lowmem_limit __initdata = 0;
void __init sanity_check_meminfo(void)
{
int i, j, highmem = 0;
#ifdef CONFIG_ENABLE_VMALLOC_SAVING
unsigned long hole_start;
for (i = 0; i < (meminfo.nr_banks - 1); i++) {
hole_start = meminfo.bank[i].start + meminfo.bank[i].size;
if (hole_start != meminfo.bank[i+1].start) {
if (hole_start <= MAX_HOLE_ADDRESS) {
vmalloc_min = (void *) (vmalloc_min +
(meminfo.bank[i+1].start - hole_start));
}
}
}
#endif
#ifdef CONFIG_DONT_MAP_HOLE_AFTER_MEMBANK0
find_memory_hole();
#endif
for (i = 0, j = 0; i < meminfo.nr_banks; i++) {
struct membank *bank = &meminfo.bank[j];
*bank = meminfo.bank[i];
if (bank->start > ULONG_MAX)
highmem = 1;
#ifdef CONFIG_HIGHMEM
if (__va(bank->start) >= vmalloc_min ||
__va(bank->start) < (void *)PAGE_OFFSET)
highmem = 1;
bank->highmem = highmem;
/*
* Split those memory banks which are partially overlapping
* the vmalloc area greatly simplifying things later.
*/
if (!highmem && __va(bank->start) < vmalloc_min &&
bank->size > vmalloc_min - __va(bank->start)) {
if (meminfo.nr_banks >= NR_BANKS) {
printk(KERN_CRIT "NR_BANKS too low, "
"ignoring high memory\n");
} else {
memmove(bank + 1, bank,
(meminfo.nr_banks - i) * sizeof(*bank));
meminfo.nr_banks++;
i++;
bank[1].size -= vmalloc_min - __va(bank->start);
bank[1].start = __pa(vmalloc_min - 1) + 1;
bank[1].highmem = highmem = 1;
j++;
}
bank->size = vmalloc_min - __va(bank->start);
}
#else
bank->highmem = highmem;
/*
* Highmem banks not allowed with !CONFIG_HIGHMEM.
*/
if (highmem) {
printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx "
"(!CONFIG_HIGHMEM).\n",
(unsigned long long)bank->start,
(unsigned long long)bank->start + bank->size - 1);
continue;
}
/*
* Check whether this memory bank would entirely overlap
* the vmalloc area.
*/
if (__va(bank->start) >= vmalloc_min ||
__va(bank->start) < (void *)PAGE_OFFSET) {
printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx "
"(vmalloc region overlap).\n",
(unsigned long long)bank->start,
(unsigned long long)bank->start + bank->size - 1);
continue;
}
/*
* Check whether this memory bank would partially overlap
* the vmalloc area.
*/
if (__va(bank->start + bank->size) > vmalloc_min ||
__va(bank->start + bank->size) < __va(bank->start)) {
unsigned long newsize = vmalloc_min - __va(bank->start);
printk(KERN_NOTICE "Truncating RAM at %.8llx-%.8llx "
"to -%.8llx (vmalloc region overlap).\n",
(unsigned long long)bank->start,
(unsigned long long)bank->start + bank->size - 1,
(unsigned long long)bank->start + newsize - 1);
bank->size = newsize;
}
#endif
if (!bank->highmem && bank->start + bank->size > arm_lowmem_limit)
arm_lowmem_limit = bank->start + bank->size;
j++;
}
#ifdef CONFIG_HIGHMEM
if (highmem) {
const char *reason = NULL;
if (cache_is_vipt_aliasing()) {
/*
* Interactions between kmap and other mappings
* make highmem support with aliasing VIPT caches
* rather difficult.
*/
reason = "with VIPT aliasing cache";
}
if (reason) {
printk(KERN_CRIT "HIGHMEM is not supported %s, ignoring high memory\n",
reason);
while (j > 0 && meminfo.bank[j - 1].highmem)
j--;
}
}
#endif
meminfo.nr_banks = j;
high_memory = __va(arm_lowmem_limit - 1) + 1;
memblock_set_current_limit(arm_lowmem_limit);
}
static inline void prepare_page_table(void)
{
unsigned long addr;
phys_addr_t end;
/*
* Clear out all the mappings below the kernel image.
*/
for (addr = 0; addr < MODULES_VADDR; addr += PMD_SIZE)
pmd_clear(pmd_off_k(addr));
#ifdef CONFIG_XIP_KERNEL
/* The XIP kernel is mapped in the module area -- skip over it */
addr = ((unsigned long)_etext + PMD_SIZE - 1) & PMD_MASK;
#endif
for ( ; addr < PAGE_OFFSET; addr += PMD_SIZE)
pmd_clear(pmd_off_k(addr));
/*
* Find the end of the first block of lowmem.
*/
end = memblock.memory.regions[0].base + memblock.memory.regions[0].size;
if (end >= arm_lowmem_limit)
end = arm_lowmem_limit;
/*
* Clear out all the kernel space mappings, except for the first
* memory bank, up to the vmalloc region.
*/
for (addr = __phys_to_virt(end);
addr < VMALLOC_START; addr += PMD_SIZE)
pmd_clear(pmd_off_k(addr));
}
#ifdef CONFIG_ARM_LPAE
/* the first page is reserved for pgd */
#define SWAPPER_PG_DIR_SIZE (PAGE_SIZE + \
PTRS_PER_PGD * PTRS_PER_PMD * sizeof(pmd_t))
#else
#define SWAPPER_PG_DIR_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
#endif
/*
* Reserve the special regions of memory
*/
void __init arm_mm_memblock_reserve(void)
{
/*
* Reserve the page tables. These are already in use,
* and can only be in node 0.
*/
memblock_reserve(__pa(swapper_pg_dir), SWAPPER_PG_DIR_SIZE);
#ifdef CONFIG_SA1111
/*
* Because of the SA1111 DMA bug, we want to preserve our
* precious DMA-able memory...
*/
memblock_reserve(PHYS_OFFSET, __pa(swapper_pg_dir) - PHYS_OFFSET);
#endif
}
/*
* Set up the device mappings. Since we clear out the page tables for all
* mappings above VMALLOC_START, we will remove any debug device mappings.
* This means you have to be careful how you debug this function, or any
* called function. This means you can't use any function or debugging
* method which may touch any device, otherwise the kernel _will_ crash.
*/
static void __init devicemaps_init(struct machine_desc *mdesc)
{
struct map_desc map;
unsigned long addr;
void *vectors;
/*
* Allocate the vector page early.
*/
vectors = early_alloc(PAGE_SIZE * 2);
early_trap_init(vectors);
for (addr = VMALLOC_START; addr; addr += PMD_SIZE)
pmd_clear(pmd_off_k(addr));
/*
* Map the kernel if it is XIP.
* It is always first in the modulearea.
*/
#ifdef CONFIG_XIP_KERNEL
map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK);
map.virtual = MODULES_VADDR;
map.length = ((unsigned long)_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK;
map.type = MT_ROM;
create_mapping(&map);
#endif
/*
* Map the cache flushing regions.
*/
#ifdef FLUSH_BASE
map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS);
map.virtual = FLUSH_BASE;
map.length = SZ_1M;
map.type = MT_CACHECLEAN;
create_mapping(&map);
#endif
#ifdef FLUSH_BASE_MINICACHE
map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + SZ_1M);
map.virtual = FLUSH_BASE_MINICACHE;
map.length = SZ_1M;
map.type = MT_MINICLEAN;
create_mapping(&map);
#endif
/*
* Create a mapping for the machine vectors at the high-vectors
* location (0xffff0000). If we aren't using high-vectors, also
* create a mapping at the low-vectors virtual address.
*/
map.pfn = __phys_to_pfn(virt_to_phys(vectors));
map.virtual = 0xffff0000;
map.length = PAGE_SIZE;
#ifdef CONFIG_KUSER_HELPERS
map.type = MT_HIGH_VECTORS;
#else
map.type = MT_LOW_VECTORS;
#endif
create_mapping(&map);
if (!vectors_high()) {
map.virtual = 0;
map.length = PAGE_SIZE * 2;
map.type = MT_LOW_VECTORS;
create_mapping(&map);
}
/* Now create a kernel read-only mapping */
map.pfn += 1;
map.virtual = 0xffff0000 + PAGE_SIZE;
map.length = PAGE_SIZE;
map.type = MT_LOW_VECTORS;
create_mapping(&map);
/*
* Ask the machine support to map in the statically mapped devices.
*/
if (mdesc->map_io)
mdesc->map_io();
fill_pmd_gaps();
if (use_user_accessible_timers()) {
/*
* Generate a mapping for the timer page.
*/
int page_addr = get_timer_page_address();
if (page_addr != ARM_USER_ACCESSIBLE_TIMERS_INVALID_PAGE) {
map.pfn = __phys_to_pfn(page_addr);
map.virtual = CONFIG_ARM_USER_ACCESSIBLE_TIMER_BASE;
map.length = PAGE_SIZE;
map.type = MT_DEVICE_USER_ACCESSIBLE;
create_mapping(&map);
}
}
/*
* Finally flush the caches and tlb to ensure that we're in a
* consistent state wrt the writebuffer. This also ensures that
* any write-allocated cache lines in the vector page are written
* back. After this point, we can start to touch devices again.
*/
local_flush_tlb_all();
flush_cache_all();
}
static void __init kmap_init(void)
{
#ifdef CONFIG_HIGHMEM
pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE),
PKMAP_BASE, _PAGE_KERNEL_TABLE);
#endif
}
#ifdef CONFIG_STRICT_MEMORY_RWX
static struct {
pmd_t *pmd_to_flush;
pmd_t *pmd;
unsigned long addr;
pmd_t saved_pmd;
bool made_writeable;
} mem_unprotect;
static DEFINE_SPINLOCK(mem_text_writeable_lock);
void mem_text_writeable_spinlock(unsigned long *flags)
{
spin_lock_irqsave(&mem_text_writeable_lock, *flags);
}
void mem_text_writeable_spinunlock(unsigned long *flags)
{
spin_unlock_irqrestore(&mem_text_writeable_lock, *flags);
}
/*
* mem_text_address_writeable() and mem_text_address_restore()
* should be called as a pair. They are used to make the
* specified address in the kernel text section temporarily writeable
* when it has been marked read-only by STRICT_MEMORY_RWX.
* Used by kprobes and other debugging tools to set breakpoints etc.
* mem_text_address_writeable() is invoked before writing.
* After the write, mem_text_address_restore() must be called
* to restore the original state.
* This is only effective when used on the kernel text section
* marked as MEMORY_RX by map_lowmem()
*
* They must each be called with mem_text_writeable_lock locked
* by the caller, with no unlocking between the calls.
* The caller should release mem_text_writeable_lock immediately
* after the call to mem_text_address_restore().
* Only the write and associated cache operations should be performed
* between the calls.
*/
/* this function must be called with mem_text_writeable_lock held */
void mem_text_address_writeable(unsigned long addr)
{
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->active_mm;
pgd_t *pgd = pgd_offset(mm, addr);
pud_t *pud = pud_offset(pgd, addr);
mem_unprotect.made_writeable = 0;
if ((addr < (unsigned long)RX_AREA_START) ||
(addr >= (unsigned long)RX_AREA_END))
return;
mem_unprotect.pmd = pmd_offset(pud, addr);
mem_unprotect.pmd_to_flush = mem_unprotect.pmd;
mem_unprotect.addr = addr & PAGE_MASK;
if (addr & SECTION_SIZE)
mem_unprotect.pmd++;
mem_unprotect.saved_pmd = *mem_unprotect.pmd;
if ((mem_unprotect.saved_pmd & PMD_TYPE_MASK) != PMD_TYPE_SECT)
return;
*mem_unprotect.pmd &= ~PMD_SECT_APX;
flush_pmd_entry(mem_unprotect.pmd_to_flush);
flush_tlb_kernel_page(mem_unprotect.addr);
mem_unprotect.made_writeable = 1;
}
/* this function must be called with mem_text_writeable_lock held */
void mem_text_address_restore(void)
{
if (mem_unprotect.made_writeable) {
*mem_unprotect.pmd = mem_unprotect.saved_pmd;
flush_pmd_entry(mem_unprotect.pmd_to_flush);
flush_tlb_kernel_page(mem_unprotect.addr);
}
}
#endif
void mem_text_write_kernel_word(unsigned long *addr, unsigned long word)
{
unsigned long flags;
mem_text_writeable_spinlock(&flags);
mem_text_address_writeable((unsigned long)addr);
*addr = word;
flush_icache_range((unsigned long)addr,
((unsigned long)addr + sizeof(long)));
mem_text_address_restore();
mem_text_writeable_spinunlock(&flags);
}
EXPORT_SYMBOL(mem_text_write_kernel_word);
static void __init map_lowmem(void)
{
struct memblock_region *reg;
struct vm_struct *vm;
phys_addr_t start;
phys_addr_t end;
unsigned long vaddr;
unsigned long pfn;
unsigned long length;
unsigned int type;
int nr = 0;
/* Map all the lowmem memory banks. */
for_each_memblock(memory, reg) {
struct map_desc map;
nr++;
start = reg->base;
end = start + reg->size;
if (end > arm_lowmem_limit)
end = arm_lowmem_limit;
if (start >= end)
break;
map.pfn = __phys_to_pfn(start);
map.virtual = __phys_to_virt(start);
#ifdef CONFIG_STRICT_MEMORY_RWX
if (start <= __pa(_text) && __pa(_text) < end) {
map.length = SECTION_SIZE;
map.type = MT_MEMORY_RW;
create_mapping(&map);
map.pfn = __phys_to_pfn(start + SECTION_SIZE);
map.virtual = __phys_to_virt(start + SECTION_SIZE);
map.length = (unsigned long)RX_AREA_END - map.virtual;
map.type = MT_MEMORY_RX;
create_mapping(&map);
map.pfn = __phys_to_pfn(__pa(__start_rodata));
map.virtual = (unsigned long)__start_rodata;
map.length = __init_begin - __start_rodata;
map.type = MT_MEMORY_R;
create_mapping(&map);
map.pfn = __phys_to_pfn(__pa(__init_begin));
map.virtual = (unsigned long)__init_begin;
map.length = (char *)__arch_info_begin - __init_begin;
map.type = MT_MEMORY_RX;
create_mapping(&map);
map.pfn = __phys_to_pfn(__pa(__arch_info_begin));
map.virtual = (unsigned long)__arch_info_begin;
map.length = __phys_to_virt(end) -
(unsigned long)__arch_info_begin;
map.type = MT_MEMORY_RW;
} else {
map.length = end - start;
map.type = MT_MEMORY_RW;
}
#else
map.length = end - start;
map.type = MT_MEMORY;
#endif
create_mapping(&map);
}
vm = early_alloc_aligned(sizeof(*vm) * nr, __alignof__(*vm));
for_each_memblock(memory, reg) {
start = reg->base;
end = start + reg->size;
if (end > arm_lowmem_limit)
end = arm_lowmem_limit;
if (start >= end)
break;
pfn = __phys_to_pfn(start);
vaddr = __phys_to_virt(start);
length = end - start;
type = MT_MEMORY;
vm->addr = (void *)(vaddr & PAGE_MASK);
vm->size = PAGE_ALIGN(length + (vaddr & ~PAGE_MASK));
vm->phys_addr = __pfn_to_phys(pfn);
vm->flags = VM_LOWMEM | VM_ARM_STATIC_MAPPING;
vm->flags |= VM_ARM_MTYPE(type);
vm->caller = map_lowmem;
vm_area_add_early(vm++);
}
}
/*
* paging_init() sets up the page tables, initialises the zone memory
* maps, and sets up the zero page, bad page and bad page tables.
*/
void __init paging_init(struct machine_desc *mdesc)
{
void *zero_page;
memblock_set_current_limit(arm_lowmem_limit);
build_mem_type_table();
prepare_page_table();
map_lowmem();
dma_contiguous_remap();
devicemaps_init(mdesc);
kmap_init();
top_pmd = pmd_off_k(0xffff0000);
/* allocate the zero page. */
zero_page = early_alloc(PAGE_SIZE);
bootmem_init();
empty_zero_page = virt_to_page(zero_page);
__flush_dcache_page(NULL, empty_zero_page);
}