/*
* Based on arch/arm/mm/mmu.c
*
* Copyright (C) 1995-2005 Russell King
* Copyright (C) 2012 ARM Ltd.
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/libfdt.h>
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/memblock.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/stop_machine.h>
#include <asm/cputype.h>
#include <asm/fixmap.h>
#include <asm/kernel-pgtable.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sizes.h>
#include <asm/tlb.h>
#include <asm/memblock.h>
#include <asm/mmu_context.h>
#include "mm.h"
u64 idmap_t0sz = TCR_T0SZ(VA_BITS);
/*
* 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);
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);
static void __init *early_alloc(unsigned long sz)
{
phys_addr_t phys;
void *ptr;
phys = memblock_alloc(sz, sz);
BUG_ON(!phys);
ptr = __va(phys);
memset(ptr, 0, sz);
return ptr;
}
/*
* remap a PMD into pages
*/
static void split_pmd(pmd_t *pmd, pte_t *pte)
{
unsigned long pfn = pmd_pfn(*pmd);
int i = 0;
do {
/*
* Need to have the least restrictive permissions available
* permissions will be fixed up later
*/
set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC));
pfn++;
} while (pte++, i++, i < PTRS_PER_PTE);
}
static void alloc_init_pte(pmd_t *pmd, unsigned long addr,
unsigned long end, unsigned long pfn,
pgprot_t prot,
void *(*alloc)(unsigned long size))
{
pte_t *pte;
if (pmd_none(*pmd) || pmd_sect(*pmd)) {
pte = alloc(PTRS_PER_PTE * sizeof(pte_t));
if (pmd_sect(*pmd))
split_pmd(pmd, pte);
__pmd_populate(pmd, __pa(pte), PMD_TYPE_TABLE);
flush_tlb_all();
}
BUG_ON(pmd_bad(*pmd));
pte = pte_offset_kernel(pmd, addr);
do {
set_pte(pte, pfn_pte(pfn, prot));
pfn++;
} while (pte++, addr += PAGE_SIZE, addr != end);
}
static void split_pud(pud_t *old_pud, pmd_t *pmd)
{
unsigned long addr = pud_pfn(*old_pud) << PAGE_SHIFT;
pgprot_t prot = __pgprot(pud_val(*old_pud) ^ addr);
int i = 0;
do {
set_pmd(pmd, __pmd(addr | pgprot_val(prot)));
addr += PMD_SIZE;
} while (pmd++, i++, i < PTRS_PER_PMD);
}
static void alloc_init_pmd(struct mm_struct *mm, pud_t *pud,
unsigned long addr, unsigned long end,
phys_addr_t phys, pgprot_t prot,
void *(*alloc)(unsigned long size))
{
pmd_t *pmd;
unsigned long next;
/*
* Check for initial section mappings in the pgd/pud and remove them.
*/
if (pud_none(*pud) || pud_sect(*pud)) {
pmd = alloc(PTRS_PER_PMD * sizeof(pmd_t));
if (pud_sect(*pud)) {
/*
* need to have the 1G of mappings continue to be
* present
*/
split_pud(pud, pmd);
}
pud_populate(mm, pud, pmd);
flush_tlb_all();
}
BUG_ON(pud_bad(*pud));
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
/* try section mapping first */
if (((addr | next | phys) & ~SECTION_MASK) == 0) {
pmd_t old_pmd =*pmd;
set_pmd(pmd, __pmd(phys |
pgprot_val(mk_sect_prot(prot))));
/*
* Check for previous table entries created during
* boot (__create_page_tables) and flush them.
*/
if (!pmd_none(old_pmd)) {
flush_tlb_all();
if (pmd_table(old_pmd)) {
phys_addr_t table = __pa(pte_offset_map(&old_pmd, 0));
if (!WARN_ON_ONCE(slab_is_available()))
memblock_free(table, PAGE_SIZE);
}
}
} else {
alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys),
prot, alloc);
}
phys += next - addr;
} while (pmd++, addr = next, addr != end);
}
static inline bool use_1G_block(unsigned long addr, unsigned long next,
unsigned long phys)
{
if (PAGE_SHIFT != 12)
return false;
if (((addr | next | phys) & ~PUD_MASK) != 0)
return false;
return true;
}
static void alloc_init_pud(struct mm_struct *mm, pgd_t *pgd,
unsigned long addr, unsigned long end,
phys_addr_t phys, pgprot_t prot,
void *(*alloc)(unsigned long size))
{
pud_t *pud;
unsigned long next;
if (pgd_none(*pgd)) {
pud = alloc(PTRS_PER_PUD * sizeof(pud_t));
pgd_populate(mm, pgd, pud);
}
BUG_ON(pgd_bad(*pgd));
pud = pud_offset(pgd, addr);
do {
next = pud_addr_end(addr, end);
/*
* For 4K granule only, attempt to put down a 1GB block
*/
if (use_1G_block(addr, next, phys)) {
pud_t old_pud = *pud;
set_pud(pud, __pud(phys |
pgprot_val(mk_sect_prot(prot))));
/*
* If we have an old value for a pud, it will
* be pointing to a pmd table that we no longer
* need (from swapper_pg_dir).
*
* Look up the old pmd table and free it.
*/
if (!pud_none(old_pud)) {
flush_tlb_all();
if (pud_table(old_pud)) {
phys_addr_t table = __pa(pmd_offset(&old_pud, 0));
if (!WARN_ON_ONCE(slab_is_available()))
memblock_free(table, PAGE_SIZE);
}
}
} else {
alloc_init_pmd(mm, pud, addr, next, phys, prot, alloc);
}
phys += next - addr;
} while (pud++, addr = next, addr != end);
}
/*
* Create the page directory entries and any necessary page tables for the
* mapping specified by 'md'.
*/
static void __create_mapping(struct mm_struct *mm, pgd_t *pgd,
phys_addr_t phys, unsigned long virt,
phys_addr_t size, pgprot_t prot,
void *(*alloc)(unsigned long size))
{
unsigned long addr, length, end, next;
addr = virt & PAGE_MASK;
length = PAGE_ALIGN(size + (virt & ~PAGE_MASK));
end = addr + length;
do {
next = pgd_addr_end(addr, end);
alloc_init_pud(mm, pgd, addr, next, phys, prot, alloc);
phys += next - addr;
} while (pgd++, addr = next, addr != end);
}
static void *late_alloc(unsigned long size)
{
void *ptr;
BUG_ON(size > PAGE_SIZE);
ptr = (void *)__get_free_page(PGALLOC_GFP);
BUG_ON(!ptr);
return ptr;
}
static void __init create_mapping(phys_addr_t phys, unsigned long virt,
phys_addr_t size, pgprot_t prot)
{
if (virt < VMALLOC_START) {
pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n",
&phys, virt);
return;
}
__create_mapping(&init_mm, pgd_offset_k(virt & PAGE_MASK), phys, virt,
size, prot, early_alloc);
}
void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
unsigned long virt, phys_addr_t size,
pgprot_t prot)
{
__create_mapping(mm, pgd_offset(mm, virt), phys, virt, size, prot,
late_alloc);
}
static void create_mapping_late(phys_addr_t phys, unsigned long virt,
phys_addr_t size, pgprot_t prot)
{
if (virt < VMALLOC_START) {
pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n",
&phys, virt);
return;
}
return __create_mapping(&init_mm, pgd_offset_k(virt & PAGE_MASK),
phys, virt, size, prot, late_alloc);
}
#ifdef CONFIG_DEBUG_RODATA
static void __init __map_memblock(phys_addr_t start, phys_addr_t end)
{
/*
* Set up the executable regions using the existing section mappings
* for now. This will get more fine grained later once all memory
* is mapped
*/
unsigned long kernel_x_start = round_down(__pa(_stext), SWAPPER_BLOCK_SIZE);
unsigned long kernel_x_end = round_up(__pa(__init_end), SWAPPER_BLOCK_SIZE);
if (end < kernel_x_start) {
create_mapping(start, __phys_to_virt(start),
end - start, PAGE_KERNEL);
} else if (start >= kernel_x_end) {
create_mapping(start, __phys_to_virt(start),
end - start, PAGE_KERNEL);
} else {
if (start < kernel_x_start)
create_mapping(start, __phys_to_virt(start),
kernel_x_start - start,
PAGE_KERNEL);
create_mapping(kernel_x_start,
__phys_to_virt(kernel_x_start),
kernel_x_end - kernel_x_start,
PAGE_KERNEL_EXEC);
if (kernel_x_end < end)
create_mapping(kernel_x_end,
__phys_to_virt(kernel_x_end),
end - kernel_x_end,
PAGE_KERNEL);
}
}
#else
static void __init __map_memblock(phys_addr_t start, phys_addr_t end)
{
create_mapping(start, __phys_to_virt(start), end - start,
PAGE_KERNEL_EXEC);
}
#endif
static void __init map_mem(void)
{
struct memblock_region *reg;
phys_addr_t limit;
/*
* Temporarily limit the memblock range. We need to do this as
* create_mapping requires puds, pmds and ptes to be allocated from
* memory addressable from the initial direct kernel mapping.
*
* The initial direct kernel mapping, located at swapper_pg_dir, gives
* us PUD_SIZE (with SECTION maps) or PMD_SIZE (without SECTION maps,
* memory starting from PHYS_OFFSET (which must be aligned to 2MB as
* per Documentation/arm64/booting.txt).
*/
limit = PHYS_OFFSET + SWAPPER_INIT_MAP_SIZE;
memblock_set_current_limit(limit);
/* map all the memory banks */
for_each_memblock(memory, reg) {
phys_addr_t start = reg->base;
phys_addr_t end = start + reg->size;
if (start >= end)
break;
if (ARM64_SWAPPER_USES_SECTION_MAPS) {
/*
* For the first memory bank align the start address and
* current memblock limit to prevent create_mapping() from
* allocating pte page tables from unmapped memory. With
* the section maps, if the first block doesn't end on section
* size boundary, create_mapping() will try to allocate a pte
* page, which may be returned from an unmapped area.
* When section maps are not used, the pte page table for the
* current limit is already present in swapper_pg_dir.
*/
if (start < limit)
start = ALIGN(start, SECTION_SIZE);
if (end < limit) {
limit = end & SECTION_MASK;
memblock_set_current_limit(limit);
}
}
__map_memblock(start, end);
}
/* Limit no longer required. */
memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
}
static void __init fixup_executable(void)
{
#ifdef CONFIG_DEBUG_RODATA
/* now that we are actually fully mapped, make the start/end more fine grained */
if (!IS_ALIGNED((unsigned long)_stext, SWAPPER_BLOCK_SIZE)) {
unsigned long aligned_start = round_down(__pa(_stext),
SWAPPER_BLOCK_SIZE);
create_mapping(aligned_start, __phys_to_virt(aligned_start),
__pa(_stext) - aligned_start,
PAGE_KERNEL);
}
if (!IS_ALIGNED((unsigned long)__init_end, SWAPPER_BLOCK_SIZE)) {
unsigned long aligned_end = round_up(__pa(__init_end),
SWAPPER_BLOCK_SIZE);
create_mapping(__pa(__init_end), (unsigned long)__init_end,
aligned_end - __pa(__init_end),
PAGE_KERNEL);
}
#endif
}
#ifdef CONFIG_DEBUG_RODATA
void mark_rodata_ro(void)
{
create_mapping_late(__pa(_stext), (unsigned long)_stext,
(unsigned long)_etext - (unsigned long)_stext,
PAGE_KERNEL_ROX);
}
#endif
void fixup_init(void)
{
create_mapping_late(__pa(__init_begin), (unsigned long)__init_begin,
(unsigned long)__init_end - (unsigned long)__init_begin,
PAGE_KERNEL);
}
/*
* paging_init() sets up the page tables, initialises the zone memory
* maps and sets up the zero page.
*/
void __init paging_init(void)
{
void *zero_page;
map_mem();
fixup_executable();
/* allocate the zero page. */
zero_page = early_alloc(PAGE_SIZE);
bootmem_init();
empty_zero_page = virt_to_page(zero_page);
/*
* TTBR0 is only used for the identity mapping at this stage. Make it
* point to zero page to avoid speculatively fetching new entries.
*/
cpu_set_reserved_ttbr0();
local_flush_tlb_all();
cpu_set_default_tcr_t0sz();
}
/*
* Check whether a kernel address is valid (derived from arch/x86/).
*/
int kern_addr_valid(unsigned long addr)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
if ((((long)addr) >> VA_BITS) != -1UL)
return 0;
pgd = pgd_offset_k(addr);
if (pgd_none(*pgd))
return 0;
pud = pud_offset(pgd, addr);
if (pud_none(*pud))
return 0;
if (pud_sect(*pud))
return pfn_valid(pud_pfn(*pud));
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd))
return 0;
if (pmd_sect(*pmd))
return pfn_valid(pmd_pfn(*pmd));
pte = pte_offset_kernel(pmd, addr);
if (pte_none(*pte))
return 0;
return pfn_valid(pte_pfn(*pte));
}
#ifdef CONFIG_SPARSEMEM_VMEMMAP
#if !ARM64_SWAPPER_USES_SECTION_MAPS
int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
{
return vmemmap_populate_basepages(start, end, node);
}
#else /* !ARM64_SWAPPER_USES_SECTION_MAPS */
int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
{
unsigned long addr = start;
unsigned long next;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
do {
next = pmd_addr_end(addr, end);
pgd = vmemmap_pgd_populate(addr, node);
if (!pgd)
return -ENOMEM;
pud = vmemmap_pud_populate(pgd, addr, node);
if (!pud)
return -ENOMEM;
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd)) {
void *p = NULL;
p = vmemmap_alloc_block_buf(PMD_SIZE, node);
if (!p)
return -ENOMEM;
set_pmd(pmd, __pmd(__pa(p) | PROT_SECT_NORMAL));
} else
vmemmap_verify((pte_t *)pmd, node, addr, next);
} while (addr = next, addr != end);
return 0;
}
#endif /* CONFIG_ARM64_64K_PAGES */
void vmemmap_free(unsigned long start, unsigned long end)
{
}
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss;
#if CONFIG_PGTABLE_LEVELS > 2
static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss;
#endif
#if CONFIG_PGTABLE_LEVELS > 3
static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss;
#endif
static inline pud_t * fixmap_pud(unsigned long addr)
{
pgd_t *pgd = pgd_offset_k(addr);
BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd));
return pud_offset(pgd, addr);
}
static inline pmd_t * fixmap_pmd(unsigned long addr)
{
pud_t *pud = fixmap_pud(addr);
BUG_ON(pud_none(*pud) || pud_bad(*pud));
return pmd_offset(pud, addr);
}
static inline pte_t * fixmap_pte(unsigned long addr)
{
pmd_t *pmd = fixmap_pmd(addr);
BUG_ON(pmd_none(*pmd) || pmd_bad(*pmd));
return pte_offset_kernel(pmd, addr);
}
void __init early_fixmap_init(void)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
unsigned long addr = FIXADDR_START;
pgd = pgd_offset_k(addr);
pgd_populate(&init_mm, pgd, bm_pud);
pud = pud_offset(pgd, addr);
pud_populate(&init_mm, pud, bm_pmd);
pmd = pmd_offset(pud, addr);
pmd_populate_kernel(&init_mm, pmd, bm_pte);
/*
* The boot-ioremap range spans multiple pmds, for which
* we are not preparted:
*/
BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
!= (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
if ((pmd != fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)))
|| pmd != fixmap_pmd(fix_to_virt(FIX_BTMAP_END))) {
WARN_ON(1);
pr_warn("pmd %p != %p, %p\n",
pmd, fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)),
fixmap_pmd(fix_to_virt(FIX_BTMAP_END)));
pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
fix_to_virt(FIX_BTMAP_BEGIN));
pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n",
fix_to_virt(FIX_BTMAP_END));
pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN);
}
}
void __set_fixmap(enum fixed_addresses idx,
phys_addr_t phys, pgprot_t flags)
{
unsigned long addr = __fix_to_virt(idx);
pte_t *pte;
BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
pte = fixmap_pte(addr);
if (pgprot_val(flags)) {
set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
} else {
pte_clear(&init_mm, addr, pte);
flush_tlb_kernel_range(addr, addr+PAGE_SIZE);
}
}
void *__init fixmap_remap_fdt(phys_addr_t dt_phys)
{
const u64 dt_virt_base = __fix_to_virt(FIX_FDT);
pgprot_t prot = PAGE_KERNEL_RO;
int size, offset;
void *dt_virt;
/*
* Check whether the physical FDT address is set and meets the minimum
* alignment requirement. Since we are relying on MIN_FDT_ALIGN to be
* at least 8 bytes so that we can always access the size field of the
* FDT header after mapping the first chunk, double check here if that
* is indeed the case.
*/
BUILD_BUG_ON(MIN_FDT_ALIGN < 8);
if (!dt_phys || dt_phys % MIN_FDT_ALIGN)
return NULL;
/*
* Make sure that the FDT region can be mapped without the need to
* allocate additional translation table pages, so that it is safe
* to call create_mapping() this early.
*
* On 64k pages, the FDT will be mapped using PTEs, so we need to
* be in the same PMD as the rest of the fixmap.
* On 4k pages, we'll use section mappings for the FDT so we only
* have to be in the same PUD.
*/
BUILD_BUG_ON(dt_virt_base % SZ_2M);
BUILD_BUG_ON(__fix_to_virt(FIX_FDT_END) >> SWAPPER_TABLE_SHIFT !=
__fix_to_virt(FIX_BTMAP_BEGIN) >> SWAPPER_TABLE_SHIFT);
offset = dt_phys % SWAPPER_BLOCK_SIZE;
dt_virt = (void *)dt_virt_base + offset;
/* map the first chunk so we can read the size from the header */
create_mapping(round_down(dt_phys, SWAPPER_BLOCK_SIZE), dt_virt_base,
SWAPPER_BLOCK_SIZE, prot);
if (fdt_check_header(dt_virt) != 0)
return NULL;
size = fdt_totalsize(dt_virt);
if (size > MAX_FDT_SIZE)
return NULL;
if (offset + size > SWAPPER_BLOCK_SIZE)
create_mapping(round_down(dt_phys, SWAPPER_BLOCK_SIZE), dt_virt_base,
round_up(offset + size, SWAPPER_BLOCK_SIZE), prot);
memblock_reserve(dt_phys, size);
return dt_virt;
}