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android-kvm / linux / b9d69371e8fa90fa3ab100f4fcb4815b13b3673a / . / arch / arm / mm / mmu.c
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// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/mm/mmu.c
*
* Copyright (C) 1995-2005 Russell King
*/
#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 <linux/sizes.h>
#include <asm/cp15.h>
#include <asm/cputype.h>
#include <asm/cachetype.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/smp_plat.h>
#include <asm/tcm.h>
#include <asm/tlb.h>
#include <asm/highmem.h>
#include <asm/system_info.h>
#include <asm/traps.h>
#include <asm/procinfo.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/kasan_def.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <asm/mach/pci.h>
#include <asm/fixmap.h>
#include "fault.h"
#include "mm.h"
extern unsigned long __atags_pointer;
/*
* 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;
pmdval_t user_pmd_table = _PAGE_USER_TABLE;
#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,
}
};
#ifdef CONFIG_CPU_CP15
static unsigned long initial_pmd_value __initdata = 0;
/*
* Initialise the cache_policy variable with the initial state specified
* via the "pmd" value. This is used to ensure that on ARMv6 and later,
* the C code sets the page tables up with the same policy as the head
* assembly code, which avoids an illegal state where the TLBs can get
* confused. See comments in early_cachepolicy() for more information.
*/
void __init init_default_cache_policy(unsigned long pmd)
{
int i;
initial_pmd_value = pmd;
pmd &= PMD_SECT_CACHE_MASK;
for (i = 0; i < ARRAY_SIZE(cache_policies); i++)
if (cache_policies[i].pmd == pmd) {
cachepolicy = i;
break;
}
if (i == ARRAY_SIZE(cache_policies))
pr_err("ERROR: could not find cache policy\n");
}
/*
* 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, selected = -1;
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) {
selected = i;
break;
}
}
if (selected == -1)
pr_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 && selected != cachepolicy) {
pr_warn("Only cachepolicy=%s supported on ARMv6 and later\n",
cache_policies[cachepolicy].policy);
return 0;
}
if (selected != cachepolicy) {
unsigned long cr = __clear_cr(cache_policies[selected].cr_mask);
cachepolicy = selected;
flush_cache_all();
set_cr(cr);
}
return 0;
}
early_param("cachepolicy", early_cachepolicy);
static int __init early_nocache(char *__unused)
{
char *p = "buffered";
pr_warn("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";
pr_warn("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
#else /* ifdef CONFIG_CPU_CP15 */
static int __init early_cachepolicy(char *p)
{
pr_warn("cachepolicy kernel parameter not supported without cp15\n");
return 0;
}
early_param("cachepolicy", early_cachepolicy);
static int __init noalign_setup(char *__unused)
{
pr_warn("noalign kernel parameter not supported without cp15\n");
return 1;
}
__setup("noalign", noalign_setup);
#endif /* ifdef CONFIG_CPU_CP15 / else */
#define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN
#define PROT_PTE_S2_DEVICE PROT_PTE_DEVICE
#define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE
static struct mem_type mem_types[] __ro_after_init = {
[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_cache */
.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_VECTORS,
},
[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_VECTORS,
},
[MT_MEMORY_RWX] = {
.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_RW] = {
.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_AP_WRITE,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_RO] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_XN | L_PTE_RDONLY,
.prot_l1 = PMD_TYPE_TABLE,
#ifdef CONFIG_ARM_LPAE
.prot_sect = PMD_TYPE_SECT | L_PMD_SECT_RDONLY | PMD_SECT_AP2,
#else
.prot_sect = PMD_TYPE_SECT,
#endif
.domain = DOMAIN_KERNEL,
},
[MT_ROM] = {
.prot_sect = PMD_TYPE_SECT,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_RWX_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_RW_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_RWX_ITCM] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
.prot_l1 = PMD_TYPE_TABLE,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_RW_SO] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_MT_UNCACHED | L_PTE_XN,
.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 |
L_PTE_XN,
.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);
static pte_t *(*pte_offset_fixmap)(pmd_t *dir, unsigned long addr);
static pte_t bm_pte[PTRS_PER_PTE + PTE_HWTABLE_PTRS]
__aligned(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE) __initdata;
static pte_t * __init pte_offset_early_fixmap(pmd_t *dir, unsigned long addr)
{
return &bm_pte[pte_index(addr)];
}
static pte_t *pte_offset_late_fixmap(pmd_t *dir, unsigned long addr)
{
return pte_offset_kernel(dir, addr);
}
static inline pmd_t * __init fixmap_pmd(unsigned long addr)
{
return pmd_off_k(addr);
}
void __init early_fixmap_init(void)
{
pmd_t *pmd;
/*
* The early fixmap range spans multiple pmds, for which
* we are not prepared:
*/
BUILD_BUG_ON((__fix_to_virt(__end_of_early_ioremap_region) >> PMD_SHIFT)
!= FIXADDR_TOP >> PMD_SHIFT);
pmd = fixmap_pmd(FIXADDR_TOP);
pmd_populate_kernel(&init_mm, pmd, bm_pte);
pte_offset_fixmap = pte_offset_early_fixmap;
}
/*
* To avoid TLB flush broadcasts, this uses local_flush_tlb_kernel_range().
* As a result, this can only be called with preemption disabled, as under
* stop_machine().
*/
void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
{
unsigned long vaddr = __fix_to_virt(idx);
pte_t *pte = pte_offset_fixmap(pmd_off_k(vaddr), vaddr);
/* Make sure fixmap region does not exceed available allocation. */
BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) < FIXADDR_START);
BUG_ON(idx >= __end_of_fixed_addresses);
/* We support only device mappings before pgprot_kernel is set. */
if (WARN_ON(pgprot_val(prot) != pgprot_val(FIXMAP_PAGE_IO) &&
pgprot_val(prot) && pgprot_val(pgprot_kernel) == 0))
return;
if (pgprot_val(prot))
set_pte_at(NULL, vaddr, pte,
pfn_pte(phys >> PAGE_SHIFT, prot));
else
pte_clear(NULL, vaddr, pte);
local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
}
static pgprot_t protection_map[16] __ro_after_init = {
[VM_NONE] = __PAGE_NONE,
[VM_READ] = __PAGE_READONLY,
[VM_WRITE] = __PAGE_COPY,
[VM_WRITE | VM_READ] = __PAGE_COPY,
[VM_EXEC] = __PAGE_READONLY_EXEC,
[VM_EXEC | VM_READ] = __PAGE_READONLY_EXEC,
[VM_EXEC | VM_WRITE] = __PAGE_COPY_EXEC,
[VM_EXEC | VM_WRITE | VM_READ] = __PAGE_COPY_EXEC,
[VM_SHARED] = __PAGE_NONE,
[VM_SHARED | VM_READ] = __PAGE_READONLY,
[VM_SHARED | VM_WRITE] = __PAGE_SHARED,
[VM_SHARED | VM_WRITE | VM_READ] = __PAGE_SHARED,
[VM_SHARED | VM_EXEC] = __PAGE_READONLY_EXEC,
[VM_SHARED | VM_EXEC | VM_READ] = __PAGE_READONLY_EXEC,
[VM_SHARED | VM_EXEC | VM_WRITE] = __PAGE_SHARED_EXEC,
[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = __PAGE_SHARED_EXEC
};
DECLARE_VM_GET_PAGE_PROT
/*
* 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()) {
if (cachepolicy != CPOLICY_WRITEALLOC) {
pr_warn("Forcing write-allocate cache policy for SMP\n");
cachepolicy = CPOLICY_WRITEALLOC;
}
if (!(initial_pmd_value & PMD_SECT_S)) {
pr_warn("Forcing shared mappings for SMP\n");
initial_pmd_value |= PMD_SECT_S;
}
}
/*
* 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_family()) {
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;
/* Also setup NX memory mapping */
mem_types[MT_MEMORY_RW].prot_sect |= PMD_SECT_XN;
mem_types[MT_MEMORY_RO].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;
#ifndef CONFIG_ARM_LPAE
/*
* We don't use domains on ARMv6 (since this causes problems with
* v6/v7 kernels), so we must use a separate memory type for user
* r/o, kernel r/w to map the vectors page.
*/
if (cpu_arch == CPU_ARCH_ARMv6)
vecs_pgprot |= L_PTE_MT_VECTORS;
/*
* Check is it with support for the PXN bit
* in the Short-descriptor translation table format descriptors.
*/
if (cpu_arch == CPU_ARCH_ARMv7 &&
(read_cpuid_ext(CPUID_EXT_MMFR0) & 0xF) >= 4) {
user_pmd_table |= PMD_PXNTABLE;
}
#endif
/*
* 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;
mem_types[MT_MEMORY_RO].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
#endif
/*
* If the initial page tables were created with the S bit
* set, then we need to do the same here for the same
* reasons given in early_cachepolicy().
*/
if (initial_pmd_value & PMD_SECT_S) {
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_RWX].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY_RWX].prot_pte |= L_PTE_SHARED;
mem_types[MT_MEMORY_RW].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY_RW].prot_pte |= L_PTE_SHARED;
mem_types[MT_MEMORY_RO].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY_RO].prot_pte |= L_PTE_SHARED;
mem_types[MT_MEMORY_DMA_READY].prot_pte |= L_PTE_SHARED;
mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY_RWX_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_RWX_NONCACHED].prot_sect |=
PMD_SECT_BUFFERED;
} else {
/* For both ARMv6 and non-TEX-remapping ARMv7 */
mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |=
PMD_SECT_TEX(1);
}
} else {
mem_types[MT_MEMORY_RWX_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;
/*
* Set PXN for user mappings
*/
user_pgprot |= PTE_EXT_PXN;
#endif
for (i = 0; i < 16; i++) {
pteval_t 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_RWX].prot_sect |= ecc_mask | cp->pmd;
mem_types[MT_MEMORY_RWX].prot_pte |= kern_pgprot;
mem_types[MT_MEMORY_RW].prot_sect |= ecc_mask | cp->pmd;
mem_types[MT_MEMORY_RW].prot_pte |= kern_pgprot;
mem_types[MT_MEMORY_RO].prot_sect |= ecc_mask | cp->pmd;
mem_types[MT_MEMORY_RO].prot_pte |= kern_pgprot;
mem_types[MT_MEMORY_DMA_READY].prot_pte |= kern_pgprot;
mem_types[MT_MEMORY_RWX_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;
}
pr_info("Memory policy: %sData cache %s\n",
ecc_mask ? "ECC enabled, " : "", 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(unsigned long sz)
{
void *ptr = memblock_alloc(sz, sz);
if (!ptr)
panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
__func__, sz, sz);
return ptr;
}
static void *__init late_alloc(unsigned long sz)
{
void *ptdesc = pagetable_alloc(GFP_PGTABLE_KERNEL & ~__GFP_HIGHMEM,
get_order(sz));
if (!ptdesc || !pagetable_pte_ctor(ptdesc))
BUG();
return ptdesc_to_virt(ptdesc);
}
static pte_t * __init arm_pte_alloc(pmd_t *pmd, unsigned long addr,
unsigned long prot,
void *(*alloc)(unsigned long sz))
{
if (pmd_none(*pmd)) {
pte_t *pte = 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 pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr,
unsigned long prot)
{
return arm_pte_alloc(pmd, addr, prot, early_alloc);
}
static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr,
unsigned long end, unsigned long pfn,
const struct mem_type *type,
void *(*alloc)(unsigned long sz),
bool ng)
{
pte_t *pte = arm_pte_alloc(pmd, addr, type->prot_l1, alloc);
do {
set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)),
ng ? PTE_EXT_NG : 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, bool ng)
{
pmd_t *p = pmd;
#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 | (ng ? PMD_SECT_nG : 0));
phys += SECTION_SIZE;
} while (pmd++, addr += SECTION_SIZE, addr != end);
flush_pmd_entry(p);
}
static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
unsigned long end, phys_addr_t phys,
const struct mem_type *type,
void *(*alloc)(unsigned long sz), bool ng)
{
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, ng);
} else {
alloc_init_pte(pmd, addr, next,
__phys_to_pfn(phys), type, alloc, ng);
}
phys += next - addr;
} while (pmd++, addr = next, addr != end);
}
static void __init alloc_init_pud(p4d_t *p4d, unsigned long addr,
unsigned long end, phys_addr_t phys,
const struct mem_type *type,
void *(*alloc)(unsigned long sz), bool ng)
{
pud_t *pud = pud_offset(p4d, addr);
unsigned long next;
do {
next = pud_addr_end(addr, end);
alloc_init_pmd(pud, addr, next, phys, type, alloc, ng);
phys += next - addr;
} while (pud++, addr = next, addr != end);
}
static void __init alloc_init_p4d(pgd_t *pgd, unsigned long addr,
unsigned long end, phys_addr_t phys,
const struct mem_type *type,
void *(*alloc)(unsigned long sz), bool ng)
{
p4d_t *p4d = p4d_offset(pgd, addr);
unsigned long next;
do {
next = p4d_addr_end(addr, end);
alloc_init_pud(p4d, addr, next, phys, type, alloc, ng);
phys += next - addr;
} while (p4d++, addr = next, addr != end);
}
#ifndef CONFIG_ARM_LPAE
static void __init create_36bit_mapping(struct mm_struct *mm,
struct map_desc *md,
const struct mem_type *type,
bool ng)
{
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())) {
pr_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) {
pr_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) {
pr_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(mm, addr);
end = addr + length;
do {
p4d_t *p4d = p4d_offset(pgd, addr);
pud_t *pud = pud_offset(p4d, 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 |
(ng ? PMD_SECT_nG : 0));
addr += SUPERSECTION_SIZE;
phys += SUPERSECTION_SIZE;
pgd += SUPERSECTION_SIZE >> PGDIR_SHIFT;
} while (addr != end);
}
#endif /* !CONFIG_ARM_LPAE */
static void __init __create_mapping(struct mm_struct *mm, struct map_desc *md,
void *(*alloc)(unsigned long sz),
bool ng)
{
unsigned long addr, length, end;
phys_addr_t phys;
const struct mem_type *type;
pgd_t *pgd;
type = &mem_types[md->type];
#ifndef CONFIG_ARM_LPAE
/*
* Catch 36-bit addresses
*/
if (md->pfn >= 0x100000) {
create_36bit_mapping(mm, md, type, ng);
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)) {
pr_warn("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(mm, addr);
end = addr + length;
do {
unsigned long next = pgd_addr_end(addr, end);
alloc_init_p4d(pgd, addr, next, phys, type, alloc, ng);
phys += next - addr;
addr = next;
} while (pgd++, addr != end);
}
/*
* 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)
{
if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) {
pr_warn("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->virtual >= PAGE_OFFSET && md->virtual < FIXADDR_START &&
(md->virtual < VMALLOC_START || md->virtual >= VMALLOC_END)) {
pr_warn("BUG: mapping for 0x%08llx at 0x%08lx out of vmalloc space\n",
(long long)__pfn_to_phys((u64)md->pfn), md->virtual);
}
__create_mapping(&init_mm, md, early_alloc, false);
}
void __init create_mapping_late(struct mm_struct *mm, struct map_desc *md,
bool ng)
{
#ifdef CONFIG_ARM_LPAE
p4d_t *p4d;
pud_t *pud;
p4d = p4d_alloc(mm, pgd_offset(mm, md->virtual), md->virtual);
if (WARN_ON(!p4d))
return;
pud = pud_alloc(mm, p4d, md->virtual);
if (WARN_ON(!pud))
return;
pmd_alloc(mm, pud, 0);
#endif
__create_mapping(mm, md, late_alloc, ng);
}
/*
* Create the architecture specific mappings
*/
void __init iotable_init(struct map_desc *io_desc, int nr)
{
struct map_desc *md;
struct vm_struct *vm;
struct static_vm *svm;
if (!nr)
return;
svm = memblock_alloc(sizeof(*svm) * nr, __alignof__(*svm));
if (!svm)
panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
__func__, sizeof(*svm) * nr, __alignof__(*svm));
for (md = io_desc; nr; md++, nr--) {
create_mapping(md);
vm = &svm->vm;
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;
add_static_vm_early(svm++);
}
}
void __init vm_reserve_area_early(unsigned long addr, unsigned long size,
void *caller)
{
struct vm_struct *vm;
struct static_vm *svm;
svm = memblock_alloc(sizeof(*svm), __alignof__(*svm));
if (!svm)
panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
__func__, sizeof(*svm), __alignof__(*svm));
vm = &svm->vm;
vm->addr = (void *)addr;
vm->size = size;
vm->flags = VM_IOREMAP | VM_ARM_EMPTY_MAPPING;
vm->caller = caller;
add_static_vm_early(svm);
}
#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)
{
vm_reserve_area_early(addr, SECTION_SIZE, pmd_empty_section_gap);
}
static void __init fill_pmd_gaps(void)
{
struct static_vm *svm;
struct vm_struct *vm;
unsigned long addr, next = 0;
pmd_t *pmd;
list_for_each_entry(svm, &static_vmlist, list) {
vm = &svm->vm;
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
#if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
static void __init pci_reserve_io(void)
{
struct static_vm *svm;
svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
if (svm)
return;
vm_reserve_area_early(PCI_IO_VIRT_BASE, SZ_2M, pci_reserve_io);
}
#else
#define pci_reserve_io() do { } while (0)
#endif
#ifdef CONFIG_DEBUG_LL
void __init debug_ll_io_init(void)
{
struct map_desc map;
debug_ll_addr(&map.pfn, &map.virtual);
if (!map.pfn || !map.virtual)
return;
map.pfn = __phys_to_pfn(map.pfn);
map.virtual &= PAGE_MASK;
map.length = PAGE_SIZE;
map.type = MT_DEVICE;
iotable_init(&map, 1);
}
#endif
static unsigned long __initdata vmalloc_size = 240 * SZ_1M;
/*
* 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 240MiB.
*/
static int __init early_vmalloc(char *arg)
{
unsigned long vmalloc_reserve = memparse(arg, NULL);
unsigned long vmalloc_max;
if (vmalloc_reserve < SZ_16M) {
vmalloc_reserve = SZ_16M;
pr_warn("vmalloc area is too small, limiting to %luMiB\n",
vmalloc_reserve >> 20);
}
vmalloc_max = VMALLOC_END - (PAGE_OFFSET + SZ_32M + VMALLOC_OFFSET);
if (vmalloc_reserve > vmalloc_max) {
vmalloc_reserve = vmalloc_max;
pr_warn("vmalloc area is too big, limiting to %luMiB\n",
vmalloc_reserve >> 20);
}
vmalloc_size = vmalloc_reserve;
return 0;
}
early_param("vmalloc", early_vmalloc);
phys_addr_t arm_lowmem_limit __initdata = 0;
void __init adjust_lowmem_bounds(void)
{
phys_addr_t block_start, block_end, memblock_limit = 0;
u64 vmalloc_limit, i;
phys_addr_t lowmem_limit = 0;
/*
* Let's use our own (unoptimized) equivalent of __pa() that is
* not affected by wrap-arounds when sizeof(phys_addr_t) == 4.
* The result is used as the upper bound on physical memory address
* and may itself be outside the valid range for which phys_addr_t
* and therefore __pa() is defined.
*/
vmalloc_limit = (u64)VMALLOC_END - vmalloc_size - VMALLOC_OFFSET -
PAGE_OFFSET + PHYS_OFFSET;
/*
* The first usable region must be PMD aligned. Mark its start
* as MEMBLOCK_NOMAP if it isn't
*/
for_each_mem_range(i, &block_start, &block_end) {
if (!IS_ALIGNED(block_start, PMD_SIZE)) {
phys_addr_t len;
len = round_up(block_start, PMD_SIZE) - block_start;
memblock_mark_nomap(block_start, len);
}
break;
}
for_each_mem_range(i, &block_start, &block_end) {
if (block_start < vmalloc_limit) {
if (block_end > lowmem_limit)
/*
* Compare as u64 to ensure vmalloc_limit does
* not get truncated. block_end should always
* fit in phys_addr_t so there should be no
* issue with assignment.
*/
lowmem_limit = min_t(u64,
vmalloc_limit,
block_end);
/*
* Find the first non-pmd-aligned page, and point
* memblock_limit at it. This relies on rounding the
* limit down to be pmd-aligned, which happens at the
* end of this function.
*
* With this algorithm, the start or end of almost any
* bank can be non-pmd-aligned. The only exception is
* that the start of the bank 0 must be section-
* aligned, since otherwise memory would need to be
* allocated when mapping the start of bank 0, which
* occurs before any free memory is mapped.
*/
if (!memblock_limit) {
if (!IS_ALIGNED(block_start, PMD_SIZE))
memblock_limit = block_start;
else if (!IS_ALIGNED(block_end, PMD_SIZE))
memblock_limit = lowmem_limit;
}
}
}
arm_lowmem_limit = lowmem_limit;
high_memory = __va(arm_lowmem_limit - 1) + 1;
if (!memblock_limit)
memblock_limit = arm_lowmem_limit;
/*
* Round the memblock limit down to a pmd size. This
* helps to ensure that we will allocate memory from the
* last full pmd, which should be mapped.
*/
memblock_limit = round_down(memblock_limit, PMD_SIZE);
if (!IS_ENABLED(CONFIG_HIGHMEM) || cache_is_vipt_aliasing()) {
if (memblock_end_of_DRAM() > arm_lowmem_limit) {
phys_addr_t end = memblock_end_of_DRAM();
pr_notice("Ignoring RAM at %pa-%pa\n",
&memblock_limit, &end);
pr_notice("Consider using a HIGHMEM enabled kernel.\n");
memblock_remove(memblock_limit, end - memblock_limit);
}
}
memblock_set_current_limit(memblock_limit);
}
static __init void prepare_page_table(void)
{
unsigned long addr;
phys_addr_t end;
/*
* Clear out all the mappings below the kernel image.
*/
#ifdef CONFIG_KASAN
/*
* KASan's shadow memory inserts itself between the TASK_SIZE
* and MODULES_VADDR. Do not clear the KASan shadow memory mappings.
*/
for (addr = 0; addr < KASAN_SHADOW_START; addr += PMD_SIZE)
pmd_clear(pmd_off_k(addr));
/*
* Skip over the KASan shadow area. KASAN_SHADOW_END is sometimes
* equal to MODULES_VADDR and then we exit the pmd clearing. If we
* are using a thumb-compiled kernel, there there will be 8MB more
* to clear as KASan always offset to 16 MB below MODULES_VADDR.
*/
for (addr = KASAN_SHADOW_END; addr < MODULES_VADDR; addr += PMD_SIZE)
pmd_clear(pmd_off_k(addr));
#else
for (addr = 0; addr < MODULES_VADDR; addr += PMD_SIZE)
pmd_clear(pmd_off_k(addr));
#endif
#ifdef CONFIG_XIP_KERNEL
/* The XIP kernel is mapped in the module area -- skip over it */
addr = ((unsigned long)_exiprom + 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, except early fixmap, we might remove debug
* device mappings. This means earlycon can be used to debug this function
* Any other function or debugging method which may touch any device _will_
* crash the kernel.
*/
static void __init devicemaps_init(const 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);
/*
* Clear page table except top pmd used by early fixmaps
*/
for (addr = VMALLOC_START; addr < (FIXADDR_TOP & PMD_MASK); addr += PMD_SIZE)
pmd_clear(pmd_off_k(addr));
if (__atags_pointer) {
/* create a read-only mapping of the device tree */
map.pfn = __phys_to_pfn(__atags_pointer & SECTION_MASK);
map.virtual = FDT_FIXED_BASE;
map.length = FDT_FIXED_SIZE;
map.type = MT_MEMORY_RO;
create_mapping(&map);
}
/*
* 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)_exiprom - 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();
else
debug_ll_io_init();
fill_pmd_gaps();
/* Reserve fixed i/o space in VMALLOC region */
pci_reserve_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();
/* Enable asynchronous aborts */
early_abt_enable();
}
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
early_pte_alloc(pmd_off_k(FIXADDR_START), FIXADDR_START,
_PAGE_KERNEL_TABLE);
}
static void __init map_lowmem(void)
{
phys_addr_t start, end;
u64 i;
/* Map all the lowmem memory banks. */
for_each_mem_range(i, &start, &end) {
struct map_desc map;
pr_debug("map lowmem start: 0x%08llx, end: 0x%08llx\n",
(long long)start, (long long)end);
if (end > arm_lowmem_limit)
end = arm_lowmem_limit;
if (start >= end)
break;
/*
* If our kernel image is in the VMALLOC area we need to remove
* the kernel physical memory from lowmem since the kernel will
* be mapped separately.
*
* The kernel will typically be at the very start of lowmem,
* but any placement relative to memory ranges is possible.
*
* If the memblock contains the kernel, we have to chisel out
* the kernel memory from it and map each part separately. We
* get 6 different theoretical cases:
*
* +--------+ +--------+
* +-- start --+ +--------+ | Kernel | | Kernel |
* | | | Kernel | | case 2 | | case 5 |
* | | | case 1 | +--------+ | | +--------+
* | Memory | +--------+ | | | Kernel |
* | range | +--------+ | | | case 6 |
* | | | Kernel | +--------+ | | +--------+
* | | | case 3 | | Kernel | | |
* +-- end ----+ +--------+ | case 4 | | |
* +--------+ +--------+
*/
/* Case 5: kernel covers range, don't map anything, should be rare */
if ((start > kernel_sec_start) && (end < kernel_sec_end))
break;
/* Cases where the kernel is starting inside the range */
if ((kernel_sec_start >= start) && (kernel_sec_start <= end)) {
/* Case 6: kernel is embedded in the range, we need two mappings */
if ((start < kernel_sec_start) && (end > kernel_sec_end)) {
/* Map memory below the kernel */
map.pfn = __phys_to_pfn(start);
map.virtual = __phys_to_virt(start);
map.length = kernel_sec_start - start;
map.type = MT_MEMORY_RW;
create_mapping(&map);
/* Map memory above the kernel */
map.pfn = __phys_to_pfn(kernel_sec_end);
map.virtual = __phys_to_virt(kernel_sec_end);
map.length = end - kernel_sec_end;
map.type = MT_MEMORY_RW;
create_mapping(&map);
break;
}
/* Case 1: kernel and range start at the same address, should be common */
if (kernel_sec_start == start)
start = kernel_sec_end;
/* Case 3: kernel and range end at the same address, should be rare */
if (kernel_sec_end == end)
end = kernel_sec_start;
} else if ((kernel_sec_start < start) && (kernel_sec_end > start) && (kernel_sec_end < end)) {
/* Case 2: kernel ends inside range, starts below it */
start = kernel_sec_end;
} else if ((kernel_sec_start > start) && (kernel_sec_start < end) && (kernel_sec_end > end)) {
/* Case 4: kernel starts inside range, ends above it */
end = kernel_sec_start;
}
map.pfn = __phys_to_pfn(start);
map.virtual = __phys_to_virt(start);
map.length = end - start;
map.type = MT_MEMORY_RW;
create_mapping(&map);
}
}
static void __init map_kernel(void)
{
/*
* We use the well known kernel section start and end and split the area in the
* middle like this:
* . .
* | RW memory |
* +----------------+ kernel_x_start
* | Executable |
* | kernel memory |
* +----------------+ kernel_x_end / kernel_nx_start
* | Non-executable |
* | kernel memory |
* +----------------+ kernel_nx_end
* | RW memory |
* . .
*
* Notice that we are dealing with section sized mappings here so all of this
* will be bumped to the closest section boundary. This means that some of the
* non-executable part of the kernel memory is actually mapped as executable.
* This will only persist until we turn on proper memory management later on
* and we remap the whole kernel with page granularity.
*/
phys_addr_t kernel_x_start = kernel_sec_start;
phys_addr_t kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE);
phys_addr_t kernel_nx_start = kernel_x_end;
phys_addr_t kernel_nx_end = kernel_sec_end;
struct map_desc map;
map.pfn = __phys_to_pfn(kernel_x_start);
map.virtual = __phys_to_virt(kernel_x_start);
map.length = kernel_x_end - kernel_x_start;
map.type = MT_MEMORY_RWX;
create_mapping(&map);
/* If the nx part is small it may end up covered by the tail of the RWX section */
if (kernel_x_end == kernel_nx_end)
return;
map.pfn = __phys_to_pfn(kernel_nx_start);
map.virtual = __phys_to_virt(kernel_nx_start);
map.length = kernel_nx_end - kernel_nx_start;
map.type = MT_MEMORY_RW;
create_mapping(&map);
}
#ifdef CONFIG_ARM_PV_FIXUP
typedef void pgtables_remap(long long offset, unsigned long pgd);
pgtables_remap lpae_pgtables_remap_asm;
/*
* early_paging_init() recreates boot time page table setup, allowing machines
* to switch over to a high (>4G) address space on LPAE systems
*/
static void __init early_paging_init(const struct machine_desc *mdesc)
{
pgtables_remap *lpae_pgtables_remap;
unsigned long pa_pgd;
u32 cr, ttbcr, tmp;
long long offset;
if (!mdesc->pv_fixup)
return;
offset = mdesc->pv_fixup();
if (offset == 0)
return;
/*
* Offset the kernel section physical offsets so that the kernel
* mapping will work out later on.
*/
kernel_sec_start += offset;
kernel_sec_end += offset;
/*
* Get the address of the remap function in the 1:1 identity
* mapping setup by the early page table assembly code. We
* must get this prior to the pv update. The following barrier
* ensures that this is complete before we fixup any P:V offsets.
*/
lpae_pgtables_remap = (pgtables_remap *)(unsigned long)__pa(lpae_pgtables_remap_asm);
pa_pgd = __pa(swapper_pg_dir);
barrier();
pr_info("Switching physical address space to 0x%08llx\n",
(u64)PHYS_OFFSET + offset);
/* Re-set the phys pfn offset, and the pv offset */
__pv_offset += offset;
__pv_phys_pfn_offset += PFN_DOWN(offset);
/* Run the patch stub to update the constants */
fixup_pv_table(&__pv_table_begin,
(&__pv_table_end - &__pv_table_begin) << 2);
/*
* We changing not only the virtual to physical mapping, but also
* the physical addresses used to access memory. We need to flush
* all levels of cache in the system with caching disabled to
* ensure that all data is written back, and nothing is prefetched
* into the caches. We also need to prevent the TLB walkers
* allocating into the caches too. Note that this is ARMv7 LPAE
* specific.
*/
cr = get_cr();
set_cr(cr & ~(CR_I | CR_C));
ttbcr = cpu_get_ttbcr();
/* Disable all kind of caching of the translation table */
tmp = ttbcr & ~(TTBCR_ORGN0_MASK | TTBCR_IRGN0_MASK);
cpu_set_ttbcr(tmp);
flush_cache_all();
/*
* Fixup the page tables - this must be in the idmap region as
* we need to disable the MMU to do this safely, and hence it
* needs to be assembly. It's fairly simple, as we're using the
* temporary tables setup by the initial assembly code.
*/
lpae_pgtables_remap(offset, pa_pgd);
/* Re-enable the caches and cacheable TLB walks */
cpu_set_ttbcr(ttbcr);
set_cr(cr);
}
#else
static void __init early_paging_init(const struct machine_desc *mdesc)
{
long long offset;
if (!mdesc->pv_fixup)
return;
offset = mdesc->pv_fixup();
if (offset == 0)
return;
pr_crit("Physical address space modification is only to support Keystone2.\n");
pr_crit("Please enable ARM_LPAE and ARM_PATCH_PHYS_VIRT support to use this\n");
pr_crit("feature. Your kernel may crash now, have a good day.\n");
add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
}
#endif
static void __init early_fixmap_shutdown(void)
{
int i;
unsigned long va = fix_to_virt(__end_of_permanent_fixed_addresses - 1);
pte_offset_fixmap = pte_offset_late_fixmap;
pmd_clear(fixmap_pmd(va));
local_flush_tlb_kernel_page(va);
for (i = 0; i < __end_of_permanent_fixed_addresses; i++) {
pte_t *pte;
struct map_desc map;
map.virtual = fix_to_virt(i);
pte = pte_offset_early_fixmap(pmd_off_k(map.virtual), map.virtual);
/* Only i/o device mappings are supported ATM */
if (pte_none(*pte) ||
(pte_val(*pte) & L_PTE_MT_MASK) != L_PTE_MT_DEV_SHARED)
continue;
map.pfn = pte_pfn(*pte);
map.type = MT_DEVICE;
map.length = PAGE_SIZE;
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(const struct machine_desc *mdesc)
{
void *zero_page;
pr_debug("physical kernel sections: 0x%08llx-0x%08llx\n",
kernel_sec_start, kernel_sec_end);
prepare_page_table();
map_lowmem();
memblock_set_current_limit(arm_lowmem_limit);
pr_debug("lowmem limit is %08llx\n", (long long)arm_lowmem_limit);
/*
* After this point early_alloc(), i.e. the memblock allocator, can
* be used
*/
map_kernel();
dma_contiguous_remap();
early_fixmap_shutdown();
devicemaps_init(mdesc);
kmap_init();
tcm_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_folio(NULL, page_folio(empty_zero_page));
}
void __init early_mm_init(const struct machine_desc *mdesc)
{
build_mem_type_table();
early_paging_init(mdesc);
}
void set_ptes(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pteval, unsigned int nr)
{
unsigned long ext = 0;
if (addr < TASK_SIZE && pte_valid_user(pteval)) {
if (!pte_special(pteval))
__sync_icache_dcache(pteval);
ext |= PTE_EXT_NG;
}
for (;;) {
set_pte_ext(ptep, pteval, ext);
if (--nr == 0)
break;
ptep++;
pteval = pte_next_pfn(pteval);
}
}