985 lines
26 KiB
C
985 lines
26 KiB
C
/*
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* Based on arch/arm/mm/mmu.c
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*
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* Copyright (C) 1995-2005 Russell King
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* Copyright (C) 2012 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/cache.h>
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#include <linux/export.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/ioport.h>
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#include <linux/kexec.h>
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#include <linux/libfdt.h>
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#include <linux/mman.h>
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#include <linux/nodemask.h>
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#include <linux/memblock.h>
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#include <linux/fs.h>
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#include <linux/io.h>
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <asm/barrier.h>
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#include <asm/cputype.h>
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#include <asm/fixmap.h>
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#include <asm/kasan.h>
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#include <asm/kernel-pgtable.h>
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#include <asm/sections.h>
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#include <asm/setup.h>
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#include <asm/sizes.h>
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#include <asm/tlb.h>
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#include <asm/memblock.h>
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#include <asm/mmu_context.h>
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#include <asm/ptdump.h>
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#define NO_BLOCK_MAPPINGS BIT(0)
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#define NO_CONT_MAPPINGS BIT(1)
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u64 idmap_t0sz = TCR_T0SZ(VA_BITS);
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u64 idmap_ptrs_per_pgd = PTRS_PER_PGD;
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u64 kimage_voffset __ro_after_init;
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EXPORT_SYMBOL(kimage_voffset);
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/*
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* Empty_zero_page is a special page that is used for zero-initialized data
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* and COW.
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*/
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unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
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EXPORT_SYMBOL(empty_zero_page);
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static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss;
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static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss __maybe_unused;
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static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss __maybe_unused;
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pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
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unsigned long size, pgprot_t vma_prot)
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{
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if (!pfn_valid(pfn))
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return pgprot_noncached(vma_prot);
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else if (file->f_flags & O_SYNC)
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return pgprot_writecombine(vma_prot);
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return vma_prot;
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}
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EXPORT_SYMBOL(phys_mem_access_prot);
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static phys_addr_t __init early_pgtable_alloc(void)
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{
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phys_addr_t phys;
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void *ptr;
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phys = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
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/*
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* The FIX_{PGD,PUD,PMD} slots may be in active use, but the FIX_PTE
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* slot will be free, so we can (ab)use the FIX_PTE slot to initialise
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* any level of table.
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*/
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ptr = pte_set_fixmap(phys);
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memset(ptr, 0, PAGE_SIZE);
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/*
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* Implicit barriers also ensure the zeroed page is visible to the page
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* table walker
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*/
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pte_clear_fixmap();
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return phys;
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}
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static bool pgattr_change_is_safe(u64 old, u64 new)
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{
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/*
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* The following mapping attributes may be updated in live
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* kernel mappings without the need for break-before-make.
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*/
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static const pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE | PTE_NG;
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/* creating or taking down mappings is always safe */
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if (old == 0 || new == 0)
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return true;
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/* live contiguous mappings may not be manipulated at all */
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if ((old | new) & PTE_CONT)
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return false;
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/* Transitioning from Non-Global to Global is unsafe */
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if (old & ~new & PTE_NG)
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return false;
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return ((old ^ new) & ~mask) == 0;
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}
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static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end,
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phys_addr_t phys, pgprot_t prot)
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{
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pte_t *ptep;
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ptep = pte_set_fixmap_offset(pmdp, addr);
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do {
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pte_t old_pte = READ_ONCE(*ptep);
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set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot));
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/*
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* After the PTE entry has been populated once, we
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* only allow updates to the permission attributes.
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*/
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BUG_ON(!pgattr_change_is_safe(pte_val(old_pte),
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READ_ONCE(pte_val(*ptep))));
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phys += PAGE_SIZE;
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} while (ptep++, addr += PAGE_SIZE, addr != end);
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pte_clear_fixmap();
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}
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static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr,
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unsigned long end, phys_addr_t phys,
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pgprot_t prot,
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phys_addr_t (*pgtable_alloc)(void),
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int flags)
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{
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unsigned long next;
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pmd_t pmd = READ_ONCE(*pmdp);
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BUG_ON(pmd_sect(pmd));
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if (pmd_none(pmd)) {
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phys_addr_t pte_phys;
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BUG_ON(!pgtable_alloc);
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pte_phys = pgtable_alloc();
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__pmd_populate(pmdp, pte_phys, PMD_TYPE_TABLE);
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pmd = READ_ONCE(*pmdp);
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}
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BUG_ON(pmd_bad(pmd));
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do {
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pgprot_t __prot = prot;
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next = pte_cont_addr_end(addr, end);
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/* use a contiguous mapping if the range is suitably aligned */
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if ((((addr | next | phys) & ~CONT_PTE_MASK) == 0) &&
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(flags & NO_CONT_MAPPINGS) == 0)
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__prot = __pgprot(pgprot_val(prot) | PTE_CONT);
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init_pte(pmdp, addr, next, phys, __prot);
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phys += next - addr;
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} while (addr = next, addr != end);
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}
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static void init_pmd(pud_t *pudp, unsigned long addr, unsigned long end,
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phys_addr_t phys, pgprot_t prot,
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phys_addr_t (*pgtable_alloc)(void), int flags)
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{
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unsigned long next;
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pmd_t *pmdp;
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pmdp = pmd_set_fixmap_offset(pudp, addr);
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do {
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pmd_t old_pmd = READ_ONCE(*pmdp);
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next = pmd_addr_end(addr, end);
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/* try section mapping first */
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if (((addr | next | phys) & ~SECTION_MASK) == 0 &&
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(flags & NO_BLOCK_MAPPINGS) == 0) {
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pmd_set_huge(pmdp, phys, prot);
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/*
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* After the PMD entry has been populated once, we
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* only allow updates to the permission attributes.
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*/
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BUG_ON(!pgattr_change_is_safe(pmd_val(old_pmd),
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READ_ONCE(pmd_val(*pmdp))));
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} else {
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alloc_init_cont_pte(pmdp, addr, next, phys, prot,
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pgtable_alloc, flags);
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BUG_ON(pmd_val(old_pmd) != 0 &&
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pmd_val(old_pmd) != READ_ONCE(pmd_val(*pmdp)));
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}
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phys += next - addr;
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} while (pmdp++, addr = next, addr != end);
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pmd_clear_fixmap();
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}
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static void alloc_init_cont_pmd(pud_t *pudp, unsigned long addr,
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unsigned long end, phys_addr_t phys,
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pgprot_t prot,
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phys_addr_t (*pgtable_alloc)(void), int flags)
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{
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unsigned long next;
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pud_t pud = READ_ONCE(*pudp);
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/*
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* Check for initial section mappings in the pgd/pud.
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*/
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BUG_ON(pud_sect(pud));
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if (pud_none(pud)) {
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phys_addr_t pmd_phys;
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BUG_ON(!pgtable_alloc);
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pmd_phys = pgtable_alloc();
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__pud_populate(pudp, pmd_phys, PUD_TYPE_TABLE);
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pud = READ_ONCE(*pudp);
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}
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BUG_ON(pud_bad(pud));
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do {
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pgprot_t __prot = prot;
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next = pmd_cont_addr_end(addr, end);
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/* use a contiguous mapping if the range is suitably aligned */
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if ((((addr | next | phys) & ~CONT_PMD_MASK) == 0) &&
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(flags & NO_CONT_MAPPINGS) == 0)
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__prot = __pgprot(pgprot_val(prot) | PTE_CONT);
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init_pmd(pudp, addr, next, phys, __prot, pgtable_alloc, flags);
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phys += next - addr;
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} while (addr = next, addr != end);
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}
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static inline bool use_1G_block(unsigned long addr, unsigned long next,
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unsigned long phys)
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{
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if (PAGE_SHIFT != 12)
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return false;
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if (((addr | next | phys) & ~PUD_MASK) != 0)
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return false;
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return true;
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}
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static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
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phys_addr_t phys, pgprot_t prot,
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phys_addr_t (*pgtable_alloc)(void),
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int flags)
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{
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unsigned long next;
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pud_t *pudp;
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pgd_t pgd = READ_ONCE(*pgdp);
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if (pgd_none(pgd)) {
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phys_addr_t pud_phys;
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BUG_ON(!pgtable_alloc);
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pud_phys = pgtable_alloc();
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__pgd_populate(pgdp, pud_phys, PUD_TYPE_TABLE);
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pgd = READ_ONCE(*pgdp);
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}
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BUG_ON(pgd_bad(pgd));
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pudp = pud_set_fixmap_offset(pgdp, addr);
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do {
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pud_t old_pud = READ_ONCE(*pudp);
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next = pud_addr_end(addr, end);
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/*
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* For 4K granule only, attempt to put down a 1GB block
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*/
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if (use_1G_block(addr, next, phys) &&
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(flags & NO_BLOCK_MAPPINGS) == 0) {
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pud_set_huge(pudp, phys, prot);
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/*
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* After the PUD entry has been populated once, we
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* only allow updates to the permission attributes.
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*/
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BUG_ON(!pgattr_change_is_safe(pud_val(old_pud),
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READ_ONCE(pud_val(*pudp))));
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} else {
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alloc_init_cont_pmd(pudp, addr, next, phys, prot,
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pgtable_alloc, flags);
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BUG_ON(pud_val(old_pud) != 0 &&
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pud_val(old_pud) != READ_ONCE(pud_val(*pudp)));
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}
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phys += next - addr;
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} while (pudp++, addr = next, addr != end);
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pud_clear_fixmap();
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}
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static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
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unsigned long virt, phys_addr_t size,
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pgprot_t prot,
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phys_addr_t (*pgtable_alloc)(void),
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int flags)
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{
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unsigned long addr, length, end, next;
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pgd_t *pgdp = pgd_offset_raw(pgdir, virt);
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/*
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* If the virtual and physical address don't have the same offset
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* within a page, we cannot map the region as the caller expects.
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*/
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if (WARN_ON((phys ^ virt) & ~PAGE_MASK))
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return;
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phys &= PAGE_MASK;
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addr = virt & PAGE_MASK;
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length = PAGE_ALIGN(size + (virt & ~PAGE_MASK));
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end = addr + length;
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do {
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next = pgd_addr_end(addr, end);
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alloc_init_pud(pgdp, addr, next, phys, prot, pgtable_alloc,
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flags);
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phys += next - addr;
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} while (pgdp++, addr = next, addr != end);
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}
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static phys_addr_t pgd_pgtable_alloc(void)
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{
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void *ptr = (void *)__get_free_page(PGALLOC_GFP);
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if (!ptr || !pgtable_page_ctor(virt_to_page(ptr)))
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BUG();
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/* Ensure the zeroed page is visible to the page table walker */
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dsb(ishst);
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return __pa(ptr);
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}
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/*
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* This function can only be used to modify existing table entries,
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* without allocating new levels of table. Note that this permits the
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* creation of new section or page entries.
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*/
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static void __init create_mapping_noalloc(phys_addr_t phys, unsigned long virt,
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phys_addr_t size, pgprot_t prot)
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{
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if (virt < VMALLOC_START) {
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pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n",
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&phys, virt);
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return;
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}
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__create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL,
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NO_CONT_MAPPINGS);
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}
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void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
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unsigned long virt, phys_addr_t size,
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pgprot_t prot, bool page_mappings_only)
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{
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int flags = 0;
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BUG_ON(mm == &init_mm);
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if (page_mappings_only)
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flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
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__create_pgd_mapping(mm->pgd, phys, virt, size, prot,
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pgd_pgtable_alloc, flags);
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}
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static void update_mapping_prot(phys_addr_t phys, unsigned long virt,
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phys_addr_t size, pgprot_t prot)
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{
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if (virt < VMALLOC_START) {
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pr_warn("BUG: not updating mapping for %pa at 0x%016lx - outside kernel range\n",
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&phys, virt);
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return;
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}
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__create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL,
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NO_CONT_MAPPINGS);
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/* flush the TLBs after updating live kernel mappings */
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flush_tlb_kernel_range(virt, virt + size);
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}
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static void __init __map_memblock(pgd_t *pgdp, phys_addr_t start,
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phys_addr_t end, pgprot_t prot, int flags)
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{
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__create_pgd_mapping(pgdp, start, __phys_to_virt(start), end - start,
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prot, early_pgtable_alloc, flags);
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}
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void __init mark_linear_text_alias_ro(void)
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{
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/*
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* Remove the write permissions from the linear alias of .text/.rodata
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*/
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update_mapping_prot(__pa_symbol(_text), (unsigned long)lm_alias(_text),
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(unsigned long)__init_begin - (unsigned long)_text,
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PAGE_KERNEL_RO);
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}
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static void __init map_mem(pgd_t *pgdp)
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{
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phys_addr_t kernel_start = __pa_symbol(_text);
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phys_addr_t kernel_end = __pa_symbol(__init_begin);
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struct memblock_region *reg;
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int flags = 0;
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if (debug_pagealloc_enabled())
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flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
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/*
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* Take care not to create a writable alias for the
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* read-only text and rodata sections of the kernel image.
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* So temporarily mark them as NOMAP to skip mappings in
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* the following for-loop
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*/
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memblock_mark_nomap(kernel_start, kernel_end - kernel_start);
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#ifdef CONFIG_KEXEC_CORE
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if (crashk_res.end)
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memblock_mark_nomap(crashk_res.start,
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resource_size(&crashk_res));
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#endif
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/* map all the memory banks */
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for_each_memblock(memory, reg) {
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phys_addr_t start = reg->base;
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phys_addr_t end = start + reg->size;
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if (start >= end)
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break;
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if (memblock_is_nomap(reg))
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continue;
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__map_memblock(pgdp, start, end, PAGE_KERNEL, flags);
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}
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/*
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* Map the linear alias of the [_text, __init_begin) interval
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* as non-executable now, and remove the write permission in
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* mark_linear_text_alias_ro() below (which will be called after
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* alternative patching has completed). This makes the contents
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* of the region accessible to subsystems such as hibernate,
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* but protects it from inadvertent modification or execution.
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* Note that contiguous mappings cannot be remapped in this way,
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* so we should avoid them here.
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*/
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__map_memblock(pgdp, kernel_start, kernel_end,
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PAGE_KERNEL, NO_CONT_MAPPINGS);
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memblock_clear_nomap(kernel_start, kernel_end - kernel_start);
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|
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#ifdef CONFIG_KEXEC_CORE
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/*
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* Use page-level mappings here so that we can shrink the region
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* in page granularity and put back unused memory to buddy system
|
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* through /sys/kernel/kexec_crash_size interface.
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*/
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if (crashk_res.end) {
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__map_memblock(pgdp, crashk_res.start, crashk_res.end + 1,
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PAGE_KERNEL,
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NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS);
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memblock_clear_nomap(crashk_res.start,
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resource_size(&crashk_res));
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}
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#endif
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}
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|
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void mark_rodata_ro(void)
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{
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unsigned long section_size;
|
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|
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/*
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* mark .rodata as read only. Use __init_begin rather than __end_rodata
|
|
* to cover NOTES and EXCEPTION_TABLE.
|
|
*/
|
|
section_size = (unsigned long)__init_begin - (unsigned long)__start_rodata;
|
|
update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata,
|
|
section_size, PAGE_KERNEL_RO);
|
|
|
|
debug_checkwx();
|
|
}
|
|
|
|
static void __init map_kernel_segment(pgd_t *pgdp, void *va_start, void *va_end,
|
|
pgprot_t prot, struct vm_struct *vma,
|
|
int flags, unsigned long vm_flags)
|
|
{
|
|
phys_addr_t pa_start = __pa_symbol(va_start);
|
|
unsigned long size = va_end - va_start;
|
|
|
|
BUG_ON(!PAGE_ALIGNED(pa_start));
|
|
BUG_ON(!PAGE_ALIGNED(size));
|
|
|
|
__create_pgd_mapping(pgdp, pa_start, (unsigned long)va_start, size, prot,
|
|
early_pgtable_alloc, flags);
|
|
|
|
if (!(vm_flags & VM_NO_GUARD))
|
|
size += PAGE_SIZE;
|
|
|
|
vma->addr = va_start;
|
|
vma->phys_addr = pa_start;
|
|
vma->size = size;
|
|
vma->flags = VM_MAP | vm_flags;
|
|
vma->caller = __builtin_return_address(0);
|
|
|
|
vm_area_add_early(vma);
|
|
}
|
|
|
|
static int __init parse_rodata(char *arg)
|
|
{
|
|
return strtobool(arg, &rodata_enabled);
|
|
}
|
|
early_param("rodata", parse_rodata);
|
|
|
|
#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
|
|
static int __init map_entry_trampoline(void)
|
|
{
|
|
pgprot_t prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
|
|
phys_addr_t pa_start = __pa_symbol(__entry_tramp_text_start);
|
|
|
|
/* The trampoline is always mapped and can therefore be global */
|
|
pgprot_val(prot) &= ~PTE_NG;
|
|
|
|
/* Map only the text into the trampoline page table */
|
|
memset(tramp_pg_dir, 0, PGD_SIZE);
|
|
__create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE,
|
|
prot, pgd_pgtable_alloc, 0);
|
|
|
|
/* Map both the text and data into the kernel page table */
|
|
__set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot);
|
|
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
|
|
extern char __entry_tramp_data_start[];
|
|
|
|
__set_fixmap(FIX_ENTRY_TRAMP_DATA,
|
|
__pa_symbol(__entry_tramp_data_start),
|
|
PAGE_KERNEL_RO);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
core_initcall(map_entry_trampoline);
|
|
#endif
|
|
|
|
/*
|
|
* Create fine-grained mappings for the kernel.
|
|
*/
|
|
static void __init map_kernel(pgd_t *pgdp)
|
|
{
|
|
static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_inittext,
|
|
vmlinux_initdata, vmlinux_data;
|
|
|
|
/*
|
|
* External debuggers may need to write directly to the text
|
|
* mapping to install SW breakpoints. Allow this (only) when
|
|
* explicitly requested with rodata=off.
|
|
*/
|
|
pgprot_t text_prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
|
|
|
|
/*
|
|
* Only rodata will be remapped with different permissions later on,
|
|
* all other segments are allowed to use contiguous mappings.
|
|
*/
|
|
map_kernel_segment(pgdp, _text, _etext, text_prot, &vmlinux_text, 0,
|
|
VM_NO_GUARD);
|
|
map_kernel_segment(pgdp, __start_rodata, __inittext_begin, PAGE_KERNEL,
|
|
&vmlinux_rodata, NO_CONT_MAPPINGS, VM_NO_GUARD);
|
|
map_kernel_segment(pgdp, __inittext_begin, __inittext_end, text_prot,
|
|
&vmlinux_inittext, 0, VM_NO_GUARD);
|
|
map_kernel_segment(pgdp, __initdata_begin, __initdata_end, PAGE_KERNEL,
|
|
&vmlinux_initdata, 0, VM_NO_GUARD);
|
|
map_kernel_segment(pgdp, _data, _end, PAGE_KERNEL, &vmlinux_data, 0, 0);
|
|
|
|
if (!READ_ONCE(pgd_val(*pgd_offset_raw(pgdp, FIXADDR_START)))) {
|
|
/*
|
|
* 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(pgdp, FIXADDR_START),
|
|
READ_ONCE(*pgd_offset_k(FIXADDR_START)));
|
|
} else if (CONFIG_PGTABLE_LEVELS > 3) {
|
|
/*
|
|
* The fixmap shares its top level pgd entry with the kernel
|
|
* mapping. This can really only occur when we are running
|
|
* with 16k/4 levels, so we can simply reuse the pud level
|
|
* entry instead.
|
|
*/
|
|
BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES));
|
|
pud_populate(&init_mm,
|
|
pud_set_fixmap_offset(pgdp, FIXADDR_START),
|
|
lm_alias(bm_pmd));
|
|
pud_clear_fixmap();
|
|
} else {
|
|
BUG();
|
|
}
|
|
|
|
kasan_copy_shadow(pgdp);
|
|
}
|
|
|
|
/*
|
|
* 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_pgtable_alloc();
|
|
pgd_t *pgdp = pgd_set_fixmap(pgd_phys);
|
|
|
|
map_kernel(pgdp);
|
|
map_mem(pgdp);
|
|
|
|
/*
|
|
* We want to reuse the original swapper_pg_dir so we don't have to
|
|
* communicate the new address to non-coherent secondaries in
|
|
* secondary_entry, and so cpu_switch_mm can generate the address with
|
|
* adrp+add rather than a load from some global variable.
|
|
*
|
|
* To do this we need to go via a temporary pgd.
|
|
*/
|
|
cpu_replace_ttbr1(__va(pgd_phys));
|
|
memcpy(swapper_pg_dir, pgdp, PGD_SIZE);
|
|
cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
|
|
|
|
pgd_clear_fixmap();
|
|
memblock_free(pgd_phys, PAGE_SIZE);
|
|
|
|
/*
|
|
* We only reuse the PGD from the swapper_pg_dir, not the pud + pmd
|
|
* allocated with it.
|
|
*/
|
|
memblock_free(__pa_symbol(swapper_pg_dir) + PAGE_SIZE,
|
|
__pa_symbol(swapper_pg_end) - __pa_symbol(swapper_pg_dir)
|
|
- PAGE_SIZE);
|
|
}
|
|
|
|
/*
|
|
* Check whether a kernel address is valid (derived from arch/x86/).
|
|
*/
|
|
int kern_addr_valid(unsigned long addr)
|
|
{
|
|
pgd_t *pgdp;
|
|
pud_t *pudp, pud;
|
|
pmd_t *pmdp, pmd;
|
|
pte_t *ptep, pte;
|
|
|
|
if ((((long)addr) >> VA_BITS) != -1UL)
|
|
return 0;
|
|
|
|
pgdp = pgd_offset_k(addr);
|
|
if (pgd_none(READ_ONCE(*pgdp)))
|
|
return 0;
|
|
|
|
pudp = pud_offset(pgdp, addr);
|
|
pud = READ_ONCE(*pudp);
|
|
if (pud_none(pud))
|
|
return 0;
|
|
|
|
if (pud_sect(pud))
|
|
return pfn_valid(pud_pfn(pud));
|
|
|
|
pmdp = pmd_offset(pudp, addr);
|
|
pmd = READ_ONCE(*pmdp);
|
|
if (pmd_none(pmd))
|
|
return 0;
|
|
|
|
if (pmd_sect(pmd))
|
|
return pfn_valid(pmd_pfn(pmd));
|
|
|
|
ptep = pte_offset_kernel(pmdp, addr);
|
|
pte = READ_ONCE(*ptep);
|
|
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,
|
|
struct vmem_altmap *altmap)
|
|
{
|
|
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,
|
|
struct vmem_altmap *altmap)
|
|
{
|
|
unsigned long addr = start;
|
|
unsigned long next;
|
|
pgd_t *pgdp;
|
|
pud_t *pudp;
|
|
pmd_t *pmdp;
|
|
|
|
do {
|
|
next = pmd_addr_end(addr, end);
|
|
|
|
pgdp = vmemmap_pgd_populate(addr, node);
|
|
if (!pgdp)
|
|
return -ENOMEM;
|
|
|
|
pudp = vmemmap_pud_populate(pgdp, addr, node);
|
|
if (!pudp)
|
|
return -ENOMEM;
|
|
|
|
pmdp = pmd_offset(pudp, addr);
|
|
if (pmd_none(READ_ONCE(*pmdp))) {
|
|
void *p = NULL;
|
|
|
|
p = vmemmap_alloc_block_buf(PMD_SIZE, node);
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
pmd_set_huge(pmdp, __pa(p), __pgprot(PROT_SECT_NORMAL));
|
|
} else
|
|
vmemmap_verify((pte_t *)pmdp, node, addr, next);
|
|
} while (addr = next, addr != end);
|
|
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_ARM64_64K_PAGES */
|
|
void vmemmap_free(unsigned long start, unsigned long end,
|
|
struct vmem_altmap *altmap)
|
|
{
|
|
}
|
|
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
|
|
|
|
static inline pud_t * fixmap_pud(unsigned long addr)
|
|
{
|
|
pgd_t *pgdp = pgd_offset_k(addr);
|
|
pgd_t pgd = READ_ONCE(*pgdp);
|
|
|
|
BUG_ON(pgd_none(pgd) || pgd_bad(pgd));
|
|
|
|
return pud_offset_kimg(pgdp, addr);
|
|
}
|
|
|
|
static inline pmd_t * fixmap_pmd(unsigned long addr)
|
|
{
|
|
pud_t *pudp = fixmap_pud(addr);
|
|
pud_t pud = READ_ONCE(*pudp);
|
|
|
|
BUG_ON(pud_none(pud) || pud_bad(pud));
|
|
|
|
return pmd_offset_kimg(pudp, addr);
|
|
}
|
|
|
|
static inline pte_t * fixmap_pte(unsigned long addr)
|
|
{
|
|
return &bm_pte[pte_index(addr)];
|
|
}
|
|
|
|
/*
|
|
* The p*d_populate functions call virt_to_phys implicitly so they can't be used
|
|
* directly on kernel symbols (bm_p*d). This function is called too early to use
|
|
* lm_alias so __p*d_populate functions must be used to populate with the
|
|
* physical address from __pa_symbol.
|
|
*/
|
|
void __init early_fixmap_init(void)
|
|
{
|
|
pgd_t *pgdp, pgd;
|
|
pud_t *pudp;
|
|
pmd_t *pmdp;
|
|
unsigned long addr = FIXADDR_START;
|
|
|
|
pgdp = pgd_offset_k(addr);
|
|
pgd = READ_ONCE(*pgdp);
|
|
if (CONFIG_PGTABLE_LEVELS > 3 &&
|
|
!(pgd_none(pgd) || pgd_page_paddr(pgd) == __pa_symbol(bm_pud))) {
|
|
/*
|
|
* We only end up here if the kernel mapping and the fixmap
|
|
* share the top level pgd entry, which should only happen on
|
|
* 16k/4 levels configurations.
|
|
*/
|
|
BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES));
|
|
pudp = pud_offset_kimg(pgdp, addr);
|
|
} else {
|
|
if (pgd_none(pgd))
|
|
__pgd_populate(pgdp, __pa_symbol(bm_pud), PUD_TYPE_TABLE);
|
|
pudp = fixmap_pud(addr);
|
|
}
|
|
if (pud_none(READ_ONCE(*pudp)))
|
|
__pud_populate(pudp, __pa_symbol(bm_pmd), PMD_TYPE_TABLE);
|
|
pmdp = fixmap_pmd(addr);
|
|
__pmd_populate(pmdp, __pa_symbol(bm_pte), PMD_TYPE_TABLE);
|
|
|
|
/*
|
|
* The boot-ioremap range spans multiple pmds, for which
|
|
* we are not prepared:
|
|
*/
|
|
BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
|
|
!= (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
|
|
|
|
if ((pmdp != fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)))
|
|
|| pmdp != fixmap_pmd(fix_to_virt(FIX_BTMAP_END))) {
|
|
WARN_ON(1);
|
|
pr_warn("pmdp %p != %p, %p\n",
|
|
pmdp, 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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Unusually, this is also called in IRQ context (ghes_iounmap_irq) so if we
|
|
* ever need to use IPIs for TLB broadcasting, then we're in trouble here.
|
|
*/
|
|
void __set_fixmap(enum fixed_addresses idx,
|
|
phys_addr_t phys, pgprot_t flags)
|
|
{
|
|
unsigned long addr = __fix_to_virt(idx);
|
|
pte_t *ptep;
|
|
|
|
BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
|
|
|
|
ptep = fixmap_pte(addr);
|
|
|
|
if (pgprot_val(flags)) {
|
|
set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, flags));
|
|
} else {
|
|
pte_clear(&init_mm, addr, ptep);
|
|
flush_tlb_kernel_range(addr, addr+PAGE_SIZE);
|
|
}
|
|
}
|
|
|
|
void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
|
|
{
|
|
const u64 dt_virt_base = __fix_to_virt(FIX_FDT);
|
|
int 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 magic and size
|
|
* fields 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_noalloc() 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_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE),
|
|
dt_virt_base, SWAPPER_BLOCK_SIZE, prot);
|
|
|
|
if (fdt_magic(dt_virt) != FDT_MAGIC)
|
|
return NULL;
|
|
|
|
*size = fdt_totalsize(dt_virt);
|
|
if (*size > MAX_FDT_SIZE)
|
|
return NULL;
|
|
|
|
if (offset + *size > SWAPPER_BLOCK_SIZE)
|
|
create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE), dt_virt_base,
|
|
round_up(offset + *size, SWAPPER_BLOCK_SIZE), prot);
|
|
|
|
return dt_virt;
|
|
}
|
|
|
|
void *__init fixmap_remap_fdt(phys_addr_t dt_phys)
|
|
{
|
|
void *dt_virt;
|
|
int size;
|
|
|
|
dt_virt = __fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO);
|
|
if (!dt_virt)
|
|
return NULL;
|
|
|
|
memblock_reserve(dt_phys, size);
|
|
return dt_virt;
|
|
}
|
|
|
|
int __init arch_ioremap_pud_supported(void)
|
|
{
|
|
/* only 4k granule supports level 1 block mappings */
|
|
return IS_ENABLED(CONFIG_ARM64_4K_PAGES);
|
|
}
|
|
|
|
int __init arch_ioremap_pmd_supported(void)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot)
|
|
{
|
|
pgprot_t sect_prot = __pgprot(PUD_TYPE_SECT |
|
|
pgprot_val(mk_sect_prot(prot)));
|
|
|
|
/* ioremap_page_range doesn't honour BBM */
|
|
if (pud_present(READ_ONCE(*pudp)))
|
|
return 0;
|
|
|
|
BUG_ON(phys & ~PUD_MASK);
|
|
set_pud(pudp, pfn_pud(__phys_to_pfn(phys), sect_prot));
|
|
return 1;
|
|
}
|
|
|
|
int pmd_set_huge(pmd_t *pmdp, phys_addr_t phys, pgprot_t prot)
|
|
{
|
|
pgprot_t sect_prot = __pgprot(PMD_TYPE_SECT |
|
|
pgprot_val(mk_sect_prot(prot)));
|
|
|
|
/* ioremap_page_range doesn't honour BBM */
|
|
if (pmd_present(READ_ONCE(*pmdp)))
|
|
return 0;
|
|
|
|
BUG_ON(phys & ~PMD_MASK);
|
|
set_pmd(pmdp, pfn_pmd(__phys_to_pfn(phys), sect_prot));
|
|
return 1;
|
|
}
|
|
|
|
int pud_clear_huge(pud_t *pudp)
|
|
{
|
|
if (!pud_sect(READ_ONCE(*pudp)))
|
|
return 0;
|
|
pud_clear(pudp);
|
|
return 1;
|
|
}
|
|
|
|
int pmd_clear_huge(pmd_t *pmdp)
|
|
{
|
|
if (!pmd_sect(READ_ONCE(*pmdp)))
|
|
return 0;
|
|
pmd_clear(pmdp);
|
|
return 1;
|
|
}
|
|
|
|
int pud_free_pmd_page(pud_t *pud)
|
|
{
|
|
return pud_none(*pud);
|
|
}
|
|
|
|
int pmd_free_pte_page(pmd_t *pmd)
|
|
{
|
|
return pmd_none(*pmd);
|
|
}
|