blob: aa4f3814e45817d78edd231140d4ddf9c0a1acf3 [file] [log] [blame]
/*
* 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.
*/
unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
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 phys_addr_t __init early_alloc(void)
{
phys_addr_t phys;
void *ptr;
phys = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
BUG_ON(!phys);
/*
* The FIX_{PGD,PUD,PMD} slots may be in active use, but the FIX_PTE
* slot will be free, so we can (ab)use the FIX_PTE slot to initialise
* any level of table.
*/
ptr = pte_fixmap(phys);
memset(ptr, 0, PAGE_SIZE);
pte_fixmap_unmap();
return phys;
}
/*
* 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,
phys_addr_t (*alloc)(void))
{
pte_t *pte;
if (pmd_none(*pmd) || pmd_sect(*pmd)) {
phys_addr_t pte_phys = alloc();
pte = pte_fixmap(pte_phys);
if (pmd_sect(*pmd))
split_pmd(pmd, pte);
__pmd_populate(pmd, pte_phys, PMD_TYPE_TABLE);
flush_tlb_all();
pte_fixmap_unmap();
}
BUG_ON(pmd_bad(*pmd));
pte = pte_fixmap_offset(pmd, addr);
do {
set_pte(pte, pfn_pte(pfn, prot));
pfn++;
} while (pte++, addr += PAGE_SIZE, addr != end);
pte_fixmap_unmap();
}
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(pud_t *pud, unsigned long addr, unsigned long end,
phys_addr_t phys, pgprot_t prot,
phys_addr_t (*alloc)(void))
{
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)) {
phys_addr_t pmd_phys = alloc();
pmd = pmd_fixmap(pmd_phys);
if (pud_sect(*pud)) {
/*
* need to have the 1G of mappings continue to be
* present
*/
split_pud(pud, pmd);
}
__pud_populate(pud, pmd_phys, PUD_TYPE_TABLE);
flush_tlb_all();
pmd_fixmap_unmap();
}
BUG_ON(pud_bad(*pud));
pmd = pmd_fixmap_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 = pmd_page_paddr(old_pmd);
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);
pmd_fixmap_unmap();
}
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(pgd_t *pgd, unsigned long addr, unsigned long end,
phys_addr_t phys, pgprot_t prot,
phys_addr_t (*alloc)(void))
{
pud_t *pud;
unsigned long next;
if (pgd_none(*pgd)) {
phys_addr_t pud_phys = alloc();
__pgd_populate(pgd, pud_phys, PUD_TYPE_TABLE);
}
BUG_ON(pgd_bad(*pgd));
pud = pud_fixmap_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 = pud_page_paddr(old_pud);
if (!WARN_ON_ONCE(slab_is_available()))
memblock_free(table, PAGE_SIZE);
}
}
} else {
alloc_init_pmd(pud, addr, next, phys, prot, alloc);
}
phys += next - addr;
} while (pud++, addr = next, addr != end);
pud_fixmap_unmap();
}
/*
* Create the page directory entries and any necessary page tables for the
* mapping specified by 'md'.
*/
static void init_pgd(pgd_t *pgd, phys_addr_t phys, unsigned long virt,
phys_addr_t size, pgprot_t prot,
phys_addr_t (*alloc)(void))
{
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(pgd, addr, next, phys, prot, alloc);
phys += next - addr;
} while (pgd++, addr = next, addr != end);
}
static phys_addr_t late_alloc(void)
{
void *ptr = (void *)__get_free_page(PGALLOC_GFP);
BUG_ON(!ptr);
return __pa(ptr);
}
static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
unsigned long virt, phys_addr_t size,
pgprot_t prot,
phys_addr_t (*alloc)(void))
{
init_pgd(pgd_offset_raw(pgdir, virt), phys, virt, size, prot, alloc);
}
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_pgd_mapping(init_mm.pgd, 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_pgd_mapping(mm->pgd, 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;
}
__create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, late_alloc);
}
static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, phys_addr_t end)
{
unsigned long kernel_start = __pa(_stext);
unsigned long kernel_end = __pa(_end);
/*
* The kernel itself is mapped at page granularity. Map all other
* memory, making sure we don't overwrite the existing kernel mappings.
*/
/* No overlap with the kernel. */
if (end < kernel_start || start >= kernel_end) {
__create_pgd_mapping(pgd, start, __phys_to_virt(start),
end - start, PAGE_KERNEL, early_alloc);
return;
}
/*
* This block overlaps the kernel mapping. Map the portion(s) which
* don't overlap.
*/
if (start < kernel_start)
__create_pgd_mapping(pgd, start,
__phys_to_virt(start),
kernel_start - start, PAGE_KERNEL,
early_alloc);
if (kernel_end < end)
__create_pgd_mapping(pgd, kernel_end,
__phys_to_virt(kernel_end),
end - kernel_end, PAGE_KERNEL,
early_alloc);
}
static void __init map_mem(pgd_t *pgd)
{
struct memblock_region *reg;
/* 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;
__map_memblock(pgd, start, end);
}
}
#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);
}
static void __init map_kernel_chunk(pgd_t *pgd, void *va_start, void *va_end, pgprot_t prot)
{
phys_addr_t pa_start = __pa(va_start);
unsigned long size = va_end - va_start;
BUG_ON(!PAGE_ALIGNED(pa_start));
BUG_ON(!PAGE_ALIGNED(size));
__create_pgd_mapping(pgd, pa_start, (unsigned long)va_start, size, prot, early_alloc);
}
/*
* Create fine-grained mappings for the kernel.
*/
static void __init map_kernel(pgd_t *pgd)
{
map_kernel_chunk(pgd, _stext, _etext, PAGE_KERNEL_EXEC);
map_kernel_chunk(pgd, __init_begin, __init_end, PAGE_KERNEL_EXEC);
map_kernel_chunk(pgd, _data, _end, PAGE_KERNEL);
/*
* The fixmap falls in a separate pgd to the kernel, and doesn't live
* in the carveout for the swapper_pg_dir. We can simply re-use the
* existing dir for the fixmap.
*/
set_pgd(pgd_offset_raw(pgd, FIXADDR_START), *pgd_offset_k(FIXADDR_START));
/* TODO: either copy or initialise KASAN here */
}
/*
* paging_init() sets up the page tables, initialises the zone memory
* maps and sets up the zero page.
*/
void __init paging_init(void)
{
phys_addr_t pgd_phys = early_alloc();
pgd_t *pgd = pgd_fixmap(pgd_phys);
map_kernel(pgd);
map_mem(pgd);
/*
* HACK: ensure that we use the original swapper_pg_dir pgd so that:
* - secondaries get the right stack in secondary_entry
* - cpu_switch_mm can validate the pgd handed to it
*/
cpu_replace_ttbr1(__va(pgd_phys));
memcpy(swapper_pg_dir, pgd, PAGE_SIZE);
cpu_replace_ttbr1(swapper_pg_dir);
/*
* TODO: this leaves the swapper_pgdir pud & pmd unused but not free.
* It would be better if we could avoid the hack above and free the
* entire swapper_pg_dir region in one go (e.g. by placing it in
* .init).
*/
pgd_fixmap_unmap();
memblock_free(pgd_phys, PAGE_SIZE);
bootmem_init();
}
/*
* 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;
}