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linux/arch/arm/mm/mmu.c
Marek Szyprowski c790950928 ARM: integrate CMA with DMA-mapping subsystem 
This patch adds support for CMA to dma-mapping subsystem for ARM
architecture. By default a global CMA area is used, but specific devices
are allowed to have their private memory areas if required (they can be
created with dma_declare_contiguous() function during board
initialisation).

Contiguous memory areas reserved for DMA are remapped with 2-level page
tables on boot. Once a buffer is requested, a low memory kernel mapping
is updated to to match requested memory access type.

GFP_ATOMIC allocations are performed from special pool which is created
early during boot. This way remapping page attributes is not needed on
allocation time.

CMA has been enabled unconditionally for ARMv6+ systems.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
2012-05-21 15:09:38 +02:00

1145 lines
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/*
* 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/mach/arch.h>
#include <asm/mach/map.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
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_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,
},
};
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);
/*
* 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_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_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_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 alloc_init_section(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);
/*
* Try a section mapping - end, addr and phys must all be aligned
* to a section boundary. Note that PMDs refer to the individual
* L1 entries, whereas PGDs refer to a group of L1 entries making
* up one logical pointer to an L2 table.
*/
if (type->prot_sect && ((addr | end | phys) & ~SECTION_MASK) == 0) {
pmd_t *p = pmd;
#ifndef CONFIG_ARM_LPAE
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(p);
} else {
/*
* No need to loop; pte's aren't interested in the
* individual L1 entries.
*/
alloc_init_pte(pmd, addr, end, __phys_to_pfn(phys), type);
}
}
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_section(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 < 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;
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;
vm_area_add_early(vm++);
}
}
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;
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);
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;
map.type = MT_HIGH_VECTORS;
create_mapping(&map);
if (!vectors_high()) {
map.virtual = 0;
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();
/*
* 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
}
static void __init map_lowmem(void)
{
struct memblock_region *reg;
/* Map all the lowmem memory banks. */
for_each_memblock(memory, reg) {
phys_addr_t start = reg->base;
phys_addr_t end = start + reg->size;
struct map_desc map;
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);
map.length = end - start;
map.type = MT_MEMORY;
create_mapping(&map);
}
}
/*
* 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);
}
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