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1639 lines
43 KiB
1639 lines
43 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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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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|
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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/memory.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 <linux/set_memory.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 <linux/sizes.h> |
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#include <asm/tlb.h> |
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#include <asm/mmu_context.h> |
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#include <asm/ptdump.h> |
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#include <asm/tlbflush.h> |
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#include <asm/pgalloc.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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#define NO_EXEC_MAPPINGS BIT(2) /* assumes FEAT_HPDS is not used */ |
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u64 idmap_t0sz = TCR_T0SZ(VA_BITS_MIN); |
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u64 idmap_ptrs_per_pgd = PTRS_PER_PGD; |
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u64 __section(".mmuoff.data.write") vabits_actual; |
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EXPORT_SYMBOL(vabits_actual); |
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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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static DEFINE_SPINLOCK(swapper_pgdir_lock); |
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void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd) |
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{ |
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pgd_t *fixmap_pgdp; |
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spin_lock(&swapper_pgdir_lock); |
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fixmap_pgdp = pgd_set_fixmap(__pa_symbol(pgdp)); |
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WRITE_ONCE(*fixmap_pgdp, pgd); |
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/* |
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* We need dsb(ishst) here to ensure the page-table-walker sees |
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* our new entry before set_p?d() returns. The fixmap's |
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* flush_tlb_kernel_range() via clear_fixmap() does this for us. |
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*/ |
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pgd_clear_fixmap(); |
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spin_unlock(&swapper_pgdir_lock); |
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} |
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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_is_map_memory(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(int shift) |
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{ |
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phys_addr_t phys; |
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void *ptr; |
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phys = memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); |
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if (!phys) |
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panic("Failed to allocate page table page\n"); |
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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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pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE | PTE_NG; |
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|
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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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/* |
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* Changing the memory type between Normal and Normal-Tagged is safe |
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* since Tagged is considered a permission attribute from the |
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* mismatched attribute aliases perspective. |
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*/ |
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if (((old & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL) || |
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(old & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL_TAGGED)) && |
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((new & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL) || |
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(new & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL_TAGGED))) |
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mask |= PTE_ATTRINDX_MASK; |
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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)(int), |
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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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pmdval_t pmdval = PMD_TYPE_TABLE | PMD_TABLE_UXN; |
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phys_addr_t pte_phys; |
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if (flags & NO_EXEC_MAPPINGS) |
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pmdval |= PMD_TABLE_PXN; |
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BUG_ON(!pgtable_alloc); |
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pte_phys = pgtable_alloc(PAGE_SHIFT); |
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__pmd_populate(pmdp, pte_phys, pmdval); |
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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)(int), 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) & ~PMD_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)(int), 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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pudval_t pudval = PUD_TYPE_TABLE | PUD_TABLE_UXN; |
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phys_addr_t pmd_phys; |
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if (flags & NO_EXEC_MAPPINGS) |
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pudval |= PUD_TABLE_PXN; |
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BUG_ON(!pgtable_alloc); |
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pmd_phys = pgtable_alloc(PMD_SHIFT); |
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__pud_populate(pudp, pmd_phys, pudval); |
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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)(int), |
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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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p4d_t *p4dp = p4d_offset(pgdp, addr); |
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p4d_t p4d = READ_ONCE(*p4dp); |
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if (p4d_none(p4d)) { |
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p4dval_t p4dval = P4D_TYPE_TABLE | P4D_TABLE_UXN; |
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phys_addr_t pud_phys; |
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if (flags & NO_EXEC_MAPPINGS) |
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p4dval |= P4D_TABLE_PXN; |
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BUG_ON(!pgtable_alloc); |
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pud_phys = pgtable_alloc(PUD_SHIFT); |
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__p4d_populate(p4dp, pud_phys, p4dval); |
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p4d = READ_ONCE(*p4dp); |
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} |
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BUG_ON(p4d_bad(p4d)); |
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pudp = pud_set_fixmap_offset(p4dp, 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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/* |
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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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/* |
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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)(int), |
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int flags) |
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{ |
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unsigned long addr, end, next; |
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pgd_t *pgdp = pgd_offset_pgd(pgdir, virt); |
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|
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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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end = PAGE_ALIGN(virt + size); |
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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(int shift) |
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{ |
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void *ptr = (void *)__get_free_page(GFP_PGTABLE_KERNEL); |
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BUG_ON(!ptr); |
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|
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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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static phys_addr_t pgd_pgtable_alloc(int shift) |
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{ |
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phys_addr_t pa = __pgd_pgtable_alloc(shift); |
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|
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/* |
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* Call proper page table ctor in case later we need to |
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* call core mm functions like apply_to_page_range() on |
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* this pre-allocated page table. |
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* |
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* We don't select ARCH_ENABLE_SPLIT_PMD_PTLOCK if pmd is |
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* folded, and if so pgtable_pmd_page_ctor() becomes nop. |
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*/ |
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if (shift == PAGE_SHIFT) |
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BUG_ON(!pgtable_pte_page_ctor(phys_to_page(pa))); |
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else if (shift == PMD_SHIFT) |
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BUG_ON(!pgtable_pmd_page_ctor(phys_to_page(pa))); |
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return pa; |
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} |
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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 >= PAGE_END) && (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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|
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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 >= PAGE_END) && (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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|
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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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|
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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(_stext), (unsigned long)lm_alias(_stext), |
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(unsigned long)__init_begin - (unsigned long)_stext, |
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PAGE_KERNEL_RO); |
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} |
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|
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static bool crash_mem_map __initdata; |
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|
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static int __init enable_crash_mem_map(char *arg) |
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{ |
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/* |
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* Proper parameter parsing is done by reserve_crashkernel(). We only |
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* need to know if the linear map has to avoid block mappings so that |
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* the crashkernel reservations can be unmapped later. |
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*/ |
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crash_mem_map = true; |
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|
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return 0; |
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} |
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early_param("crashkernel", enable_crash_mem_map); |
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|
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static void __init map_mem(pgd_t *pgdp) |
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{ |
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static const u64 direct_map_end = _PAGE_END(VA_BITS_MIN); |
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phys_addr_t kernel_start = __pa_symbol(_stext); |
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phys_addr_t kernel_end = __pa_symbol(__init_begin); |
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phys_addr_t start, end; |
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int flags = NO_EXEC_MAPPINGS; |
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u64 i; |
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|
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/* |
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* Setting hierarchical PXNTable attributes on table entries covering |
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* the linear region is only possible if it is guaranteed that no table |
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* entries at any level are being shared between the linear region and |
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* the vmalloc region. Check whether this is true for the PGD level, in |
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* which case it is guaranteed to be true for all other levels as well. |
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*/ |
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BUILD_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end)); |
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|
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if (can_set_direct_map() || crash_mem_map || IS_ENABLED(CONFIG_KFENCE)) |
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flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; |
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|
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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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|
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/* map all the memory banks */ |
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for_each_mem_range(i, &start, &end) { |
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if (start >= end) |
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break; |
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/* |
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* The linear map must allow allocation tags reading/writing |
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* if MTE is present. Otherwise, it has the same attributes as |
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* PAGE_KERNEL. |
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*/ |
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__map_memblock(pgdp, start, end, pgprot_tagged(PAGE_KERNEL), |
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flags); |
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} |
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|
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/* |
|
* Map the linear alias of the [_stext, __init_begin) interval |
|
* as non-executable now, and remove the write permission in |
|
* mark_linear_text_alias_ro() below (which will be called after |
|
* alternative patching has completed). This makes the contents |
|
* of the region accessible to subsystems such as hibernate, |
|
* but protects it from inadvertent modification or execution. |
|
* Note that contiguous mappings cannot be remapped in this way, |
|
* so we should avoid them here. |
|
*/ |
|
__map_memblock(pgdp, kernel_start, kernel_end, |
|
PAGE_KERNEL, NO_CONT_MAPPINGS); |
|
memblock_clear_nomap(kernel_start, kernel_end - kernel_start); |
|
} |
|
|
|
void mark_rodata_ro(void) |
|
{ |
|
unsigned long section_size; |
|
|
|
/* |
|
* 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) |
|
{ |
|
int ret = strtobool(arg, &rodata_enabled); |
|
if (!ret) { |
|
rodata_full = false; |
|
return 0; |
|
} |
|
|
|
/* permit 'full' in addition to boolean options */ |
|
if (strcmp(arg, "full")) |
|
return -EINVAL; |
|
|
|
rodata_enabled = true; |
|
rodata_full = true; |
|
return 0; |
|
} |
|
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 |
|
|
|
/* |
|
* Open coded check for BTI, only for use to determine configuration |
|
* for early mappings for before the cpufeature code has run. |
|
*/ |
|
static bool arm64_early_this_cpu_has_bti(void) |
|
{ |
|
u64 pfr1; |
|
|
|
if (!IS_ENABLED(CONFIG_ARM64_BTI_KERNEL)) |
|
return false; |
|
|
|
pfr1 = __read_sysreg_by_encoding(SYS_ID_AA64PFR1_EL1); |
|
return cpuid_feature_extract_unsigned_field(pfr1, |
|
ID_AA64PFR1_BT_SHIFT); |
|
} |
|
|
|
/* |
|
* 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; |
|
|
|
/* |
|
* If we have a CPU that supports BTI and a kernel built for |
|
* BTI then mark the kernel executable text as guarded pages |
|
* now so we don't have to rewrite the page tables later. |
|
*/ |
|
if (arm64_early_this_cpu_has_bti()) |
|
text_prot = __pgprot_modify(text_prot, PTE_GP, PTE_GP); |
|
|
|
/* |
|
* Only rodata will be remapped with different permissions later on, |
|
* all other segments are allowed to use contiguous mappings. |
|
*/ |
|
map_kernel_segment(pgdp, _stext, _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_pgd(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_pgd(pgdp, FIXADDR_START), |
|
READ_ONCE(*pgd_offset_k(FIXADDR_START))); |
|
} else if (CONFIG_PGTABLE_LEVELS > 3) { |
|
pgd_t *bm_pgdp; |
|
p4d_t *bm_p4dp; |
|
pud_t *bm_pudp; |
|
/* |
|
* 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)); |
|
bm_pgdp = pgd_offset_pgd(pgdp, FIXADDR_START); |
|
bm_p4dp = p4d_offset(bm_pgdp, FIXADDR_START); |
|
bm_pudp = pud_set_fixmap_offset(bm_p4dp, FIXADDR_START); |
|
pud_populate(&init_mm, bm_pudp, lm_alias(bm_pmd)); |
|
pud_clear_fixmap(); |
|
} else { |
|
BUG(); |
|
} |
|
|
|
kasan_copy_shadow(pgdp); |
|
} |
|
|
|
void __init paging_init(void) |
|
{ |
|
pgd_t *pgdp = pgd_set_fixmap(__pa_symbol(swapper_pg_dir)); |
|
|
|
map_kernel(pgdp); |
|
map_mem(pgdp); |
|
|
|
pgd_clear_fixmap(); |
|
|
|
cpu_replace_ttbr1(lm_alias(swapper_pg_dir)); |
|
init_mm.pgd = swapper_pg_dir; |
|
|
|
memblock_free(__pa_symbol(init_pg_dir), |
|
__pa_symbol(init_pg_end) - __pa_symbol(init_pg_dir)); |
|
|
|
memblock_allow_resize(); |
|
} |
|
|
|
/* |
|
* Check whether a kernel address is valid (derived from arch/x86/). |
|
*/ |
|
int kern_addr_valid(unsigned long addr) |
|
{ |
|
pgd_t *pgdp; |
|
p4d_t *p4dp; |
|
pud_t *pudp, pud; |
|
pmd_t *pmdp, pmd; |
|
pte_t *ptep, pte; |
|
|
|
addr = arch_kasan_reset_tag(addr); |
|
if ((((long)addr) >> VA_BITS) != -1UL) |
|
return 0; |
|
|
|
pgdp = pgd_offset_k(addr); |
|
if (pgd_none(READ_ONCE(*pgdp))) |
|
return 0; |
|
|
|
p4dp = p4d_offset(pgdp, addr); |
|
if (p4d_none(READ_ONCE(*p4dp))) |
|
return 0; |
|
|
|
pudp = pud_offset(p4dp, 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_MEMORY_HOTPLUG |
|
static void free_hotplug_page_range(struct page *page, size_t size, |
|
struct vmem_altmap *altmap) |
|
{ |
|
if (altmap) { |
|
vmem_altmap_free(altmap, size >> PAGE_SHIFT); |
|
} else { |
|
WARN_ON(PageReserved(page)); |
|
free_pages((unsigned long)page_address(page), get_order(size)); |
|
} |
|
} |
|
|
|
static void free_hotplug_pgtable_page(struct page *page) |
|
{ |
|
free_hotplug_page_range(page, PAGE_SIZE, NULL); |
|
} |
|
|
|
static bool pgtable_range_aligned(unsigned long start, unsigned long end, |
|
unsigned long floor, unsigned long ceiling, |
|
unsigned long mask) |
|
{ |
|
start &= mask; |
|
if (start < floor) |
|
return false; |
|
|
|
if (ceiling) { |
|
ceiling &= mask; |
|
if (!ceiling) |
|
return false; |
|
} |
|
|
|
if (end - 1 > ceiling - 1) |
|
return false; |
|
return true; |
|
} |
|
|
|
static void unmap_hotplug_pte_range(pmd_t *pmdp, unsigned long addr, |
|
unsigned long end, bool free_mapped, |
|
struct vmem_altmap *altmap) |
|
{ |
|
pte_t *ptep, pte; |
|
|
|
do { |
|
ptep = pte_offset_kernel(pmdp, addr); |
|
pte = READ_ONCE(*ptep); |
|
if (pte_none(pte)) |
|
continue; |
|
|
|
WARN_ON(!pte_present(pte)); |
|
pte_clear(&init_mm, addr, ptep); |
|
flush_tlb_kernel_range(addr, addr + PAGE_SIZE); |
|
if (free_mapped) |
|
free_hotplug_page_range(pte_page(pte), |
|
PAGE_SIZE, altmap); |
|
} while (addr += PAGE_SIZE, addr < end); |
|
} |
|
|
|
static void unmap_hotplug_pmd_range(pud_t *pudp, unsigned long addr, |
|
unsigned long end, bool free_mapped, |
|
struct vmem_altmap *altmap) |
|
{ |
|
unsigned long next; |
|
pmd_t *pmdp, pmd; |
|
|
|
do { |
|
next = pmd_addr_end(addr, end); |
|
pmdp = pmd_offset(pudp, addr); |
|
pmd = READ_ONCE(*pmdp); |
|
if (pmd_none(pmd)) |
|
continue; |
|
|
|
WARN_ON(!pmd_present(pmd)); |
|
if (pmd_sect(pmd)) { |
|
pmd_clear(pmdp); |
|
|
|
/* |
|
* One TLBI should be sufficient here as the PMD_SIZE |
|
* range is mapped with a single block entry. |
|
*/ |
|
flush_tlb_kernel_range(addr, addr + PAGE_SIZE); |
|
if (free_mapped) |
|
free_hotplug_page_range(pmd_page(pmd), |
|
PMD_SIZE, altmap); |
|
continue; |
|
} |
|
WARN_ON(!pmd_table(pmd)); |
|
unmap_hotplug_pte_range(pmdp, addr, next, free_mapped, altmap); |
|
} while (addr = next, addr < end); |
|
} |
|
|
|
static void unmap_hotplug_pud_range(p4d_t *p4dp, unsigned long addr, |
|
unsigned long end, bool free_mapped, |
|
struct vmem_altmap *altmap) |
|
{ |
|
unsigned long next; |
|
pud_t *pudp, pud; |
|
|
|
do { |
|
next = pud_addr_end(addr, end); |
|
pudp = pud_offset(p4dp, addr); |
|
pud = READ_ONCE(*pudp); |
|
if (pud_none(pud)) |
|
continue; |
|
|
|
WARN_ON(!pud_present(pud)); |
|
if (pud_sect(pud)) { |
|
pud_clear(pudp); |
|
|
|
/* |
|
* One TLBI should be sufficient here as the PUD_SIZE |
|
* range is mapped with a single block entry. |
|
*/ |
|
flush_tlb_kernel_range(addr, addr + PAGE_SIZE); |
|
if (free_mapped) |
|
free_hotplug_page_range(pud_page(pud), |
|
PUD_SIZE, altmap); |
|
continue; |
|
} |
|
WARN_ON(!pud_table(pud)); |
|
unmap_hotplug_pmd_range(pudp, addr, next, free_mapped, altmap); |
|
} while (addr = next, addr < end); |
|
} |
|
|
|
static void unmap_hotplug_p4d_range(pgd_t *pgdp, unsigned long addr, |
|
unsigned long end, bool free_mapped, |
|
struct vmem_altmap *altmap) |
|
{ |
|
unsigned long next; |
|
p4d_t *p4dp, p4d; |
|
|
|
do { |
|
next = p4d_addr_end(addr, end); |
|
p4dp = p4d_offset(pgdp, addr); |
|
p4d = READ_ONCE(*p4dp); |
|
if (p4d_none(p4d)) |
|
continue; |
|
|
|
WARN_ON(!p4d_present(p4d)); |
|
unmap_hotplug_pud_range(p4dp, addr, next, free_mapped, altmap); |
|
} while (addr = next, addr < end); |
|
} |
|
|
|
static void unmap_hotplug_range(unsigned long addr, unsigned long end, |
|
bool free_mapped, struct vmem_altmap *altmap) |
|
{ |
|
unsigned long next; |
|
pgd_t *pgdp, pgd; |
|
|
|
/* |
|
* altmap can only be used as vmemmap mapping backing memory. |
|
* In case the backing memory itself is not being freed, then |
|
* altmap is irrelevant. Warn about this inconsistency when |
|
* encountered. |
|
*/ |
|
WARN_ON(!free_mapped && altmap); |
|
|
|
do { |
|
next = pgd_addr_end(addr, end); |
|
pgdp = pgd_offset_k(addr); |
|
pgd = READ_ONCE(*pgdp); |
|
if (pgd_none(pgd)) |
|
continue; |
|
|
|
WARN_ON(!pgd_present(pgd)); |
|
unmap_hotplug_p4d_range(pgdp, addr, next, free_mapped, altmap); |
|
} while (addr = next, addr < end); |
|
} |
|
|
|
static void free_empty_pte_table(pmd_t *pmdp, unsigned long addr, |
|
unsigned long end, unsigned long floor, |
|
unsigned long ceiling) |
|
{ |
|
pte_t *ptep, pte; |
|
unsigned long i, start = addr; |
|
|
|
do { |
|
ptep = pte_offset_kernel(pmdp, addr); |
|
pte = READ_ONCE(*ptep); |
|
|
|
/* |
|
* This is just a sanity check here which verifies that |
|
* pte clearing has been done by earlier unmap loops. |
|
*/ |
|
WARN_ON(!pte_none(pte)); |
|
} while (addr += PAGE_SIZE, addr < end); |
|
|
|
if (!pgtable_range_aligned(start, end, floor, ceiling, PMD_MASK)) |
|
return; |
|
|
|
/* |
|
* Check whether we can free the pte page if the rest of the |
|
* entries are empty. Overlap with other regions have been |
|
* handled by the floor/ceiling check. |
|
*/ |
|
ptep = pte_offset_kernel(pmdp, 0UL); |
|
for (i = 0; i < PTRS_PER_PTE; i++) { |
|
if (!pte_none(READ_ONCE(ptep[i]))) |
|
return; |
|
} |
|
|
|
pmd_clear(pmdp); |
|
__flush_tlb_kernel_pgtable(start); |
|
free_hotplug_pgtable_page(virt_to_page(ptep)); |
|
} |
|
|
|
static void free_empty_pmd_table(pud_t *pudp, unsigned long addr, |
|
unsigned long end, unsigned long floor, |
|
unsigned long ceiling) |
|
{ |
|
pmd_t *pmdp, pmd; |
|
unsigned long i, next, start = addr; |
|
|
|
do { |
|
next = pmd_addr_end(addr, end); |
|
pmdp = pmd_offset(pudp, addr); |
|
pmd = READ_ONCE(*pmdp); |
|
if (pmd_none(pmd)) |
|
continue; |
|
|
|
WARN_ON(!pmd_present(pmd) || !pmd_table(pmd) || pmd_sect(pmd)); |
|
free_empty_pte_table(pmdp, addr, next, floor, ceiling); |
|
} while (addr = next, addr < end); |
|
|
|
if (CONFIG_PGTABLE_LEVELS <= 2) |
|
return; |
|
|
|
if (!pgtable_range_aligned(start, end, floor, ceiling, PUD_MASK)) |
|
return; |
|
|
|
/* |
|
* Check whether we can free the pmd page if the rest of the |
|
* entries are empty. Overlap with other regions have been |
|
* handled by the floor/ceiling check. |
|
*/ |
|
pmdp = pmd_offset(pudp, 0UL); |
|
for (i = 0; i < PTRS_PER_PMD; i++) { |
|
if (!pmd_none(READ_ONCE(pmdp[i]))) |
|
return; |
|
} |
|
|
|
pud_clear(pudp); |
|
__flush_tlb_kernel_pgtable(start); |
|
free_hotplug_pgtable_page(virt_to_page(pmdp)); |
|
} |
|
|
|
static void free_empty_pud_table(p4d_t *p4dp, unsigned long addr, |
|
unsigned long end, unsigned long floor, |
|
unsigned long ceiling) |
|
{ |
|
pud_t *pudp, pud; |
|
unsigned long i, next, start = addr; |
|
|
|
do { |
|
next = pud_addr_end(addr, end); |
|
pudp = pud_offset(p4dp, addr); |
|
pud = READ_ONCE(*pudp); |
|
if (pud_none(pud)) |
|
continue; |
|
|
|
WARN_ON(!pud_present(pud) || !pud_table(pud) || pud_sect(pud)); |
|
free_empty_pmd_table(pudp, addr, next, floor, ceiling); |
|
} while (addr = next, addr < end); |
|
|
|
if (CONFIG_PGTABLE_LEVELS <= 3) |
|
return; |
|
|
|
if (!pgtable_range_aligned(start, end, floor, ceiling, PGDIR_MASK)) |
|
return; |
|
|
|
/* |
|
* Check whether we can free the pud page if the rest of the |
|
* entries are empty. Overlap with other regions have been |
|
* handled by the floor/ceiling check. |
|
*/ |
|
pudp = pud_offset(p4dp, 0UL); |
|
for (i = 0; i < PTRS_PER_PUD; i++) { |
|
if (!pud_none(READ_ONCE(pudp[i]))) |
|
return; |
|
} |
|
|
|
p4d_clear(p4dp); |
|
__flush_tlb_kernel_pgtable(start); |
|
free_hotplug_pgtable_page(virt_to_page(pudp)); |
|
} |
|
|
|
static void free_empty_p4d_table(pgd_t *pgdp, unsigned long addr, |
|
unsigned long end, unsigned long floor, |
|
unsigned long ceiling) |
|
{ |
|
unsigned long next; |
|
p4d_t *p4dp, p4d; |
|
|
|
do { |
|
next = p4d_addr_end(addr, end); |
|
p4dp = p4d_offset(pgdp, addr); |
|
p4d = READ_ONCE(*p4dp); |
|
if (p4d_none(p4d)) |
|
continue; |
|
|
|
WARN_ON(!p4d_present(p4d)); |
|
free_empty_pud_table(p4dp, addr, next, floor, ceiling); |
|
} while (addr = next, addr < end); |
|
} |
|
|
|
static void free_empty_tables(unsigned long addr, unsigned long end, |
|
unsigned long floor, unsigned long ceiling) |
|
{ |
|
unsigned long next; |
|
pgd_t *pgdp, pgd; |
|
|
|
do { |
|
next = pgd_addr_end(addr, end); |
|
pgdp = pgd_offset_k(addr); |
|
pgd = READ_ONCE(*pgdp); |
|
if (pgd_none(pgd)) |
|
continue; |
|
|
|
WARN_ON(!pgd_present(pgd)); |
|
free_empty_p4d_table(pgdp, addr, next, floor, ceiling); |
|
} while (addr = next, addr < end); |
|
} |
|
#endif |
|
|
|
#if !ARM64_KERNEL_USES_PMD_MAPS |
|
int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, |
|
struct vmem_altmap *altmap) |
|
{ |
|
WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END)); |
|
return vmemmap_populate_basepages(start, end, node, altmap); |
|
} |
|
#else /* !ARM64_KERNEL_USES_PMD_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; |
|
p4d_t *p4dp; |
|
pud_t *pudp; |
|
pmd_t *pmdp; |
|
|
|
WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END)); |
|
do { |
|
next = pmd_addr_end(addr, end); |
|
|
|
pgdp = vmemmap_pgd_populate(addr, node); |
|
if (!pgdp) |
|
return -ENOMEM; |
|
|
|
p4dp = vmemmap_p4d_populate(pgdp, addr, node); |
|
if (!p4dp) |
|
return -ENOMEM; |
|
|
|
pudp = vmemmap_pud_populate(p4dp, 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, altmap); |
|
if (!p) { |
|
if (vmemmap_populate_basepages(addr, next, node, altmap)) |
|
return -ENOMEM; |
|
continue; |
|
} |
|
|
|
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 /* !ARM64_KERNEL_USES_PMD_MAPS */ |
|
|
|
#ifdef CONFIG_MEMORY_HOTPLUG |
|
void vmemmap_free(unsigned long start, unsigned long end, |
|
struct vmem_altmap *altmap) |
|
{ |
|
WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END)); |
|
|
|
unmap_hotplug_range(start, end, true, altmap); |
|
free_empty_tables(start, end, VMEMMAP_START, VMEMMAP_END); |
|
} |
|
#endif /* CONFIG_MEMORY_HOTPLUG */ |
|
|
|
static inline pud_t *fixmap_pud(unsigned long addr) |
|
{ |
|
pgd_t *pgdp = pgd_offset_k(addr); |
|
p4d_t *p4dp = p4d_offset(pgdp, addr); |
|
p4d_t p4d = READ_ONCE(*p4dp); |
|
|
|
BUG_ON(p4d_none(p4d) || p4d_bad(p4d)); |
|
|
|
return pud_offset_kimg(p4dp, 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; |
|
p4d_t *p4dp, p4d; |
|
pud_t *pudp; |
|
pmd_t *pmdp; |
|
unsigned long addr = FIXADDR_START; |
|
|
|
pgdp = pgd_offset_k(addr); |
|
p4dp = p4d_offset(pgdp, addr); |
|
p4d = READ_ONCE(*p4dp); |
|
if (CONFIG_PGTABLE_LEVELS > 3 && |
|
!(p4d_none(p4d) || p4d_page_paddr(p4d) == __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(p4dp, addr); |
|
} else { |
|
if (p4d_none(p4d)) |
|
__p4d_populate(p4dp, __pa_symbol(bm_pud), P4D_TYPE_TABLE); |
|
pudp = fixmap_pud(addr); |
|
} |
|
if (pud_none(READ_ONCE(*pudp))) |
|
__pud_populate(pudp, __pa_symbol(bm_pmd), PUD_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; |
|
} |
|
|
|
int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot) |
|
{ |
|
pud_t new_pud = pfn_pud(__phys_to_pfn(phys), mk_pud_sect_prot(prot)); |
|
|
|
/* Only allow permission changes for now */ |
|
if (!pgattr_change_is_safe(READ_ONCE(pud_val(*pudp)), |
|
pud_val(new_pud))) |
|
return 0; |
|
|
|
VM_BUG_ON(phys & ~PUD_MASK); |
|
set_pud(pudp, new_pud); |
|
return 1; |
|
} |
|
|
|
int pmd_set_huge(pmd_t *pmdp, phys_addr_t phys, pgprot_t prot) |
|
{ |
|
pmd_t new_pmd = pfn_pmd(__phys_to_pfn(phys), mk_pmd_sect_prot(prot)); |
|
|
|
/* Only allow permission changes for now */ |
|
if (!pgattr_change_is_safe(READ_ONCE(pmd_val(*pmdp)), |
|
pmd_val(new_pmd))) |
|
return 0; |
|
|
|
VM_BUG_ON(phys & ~PMD_MASK); |
|
set_pmd(pmdp, new_pmd); |
|
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 pmd_free_pte_page(pmd_t *pmdp, unsigned long addr) |
|
{ |
|
pte_t *table; |
|
pmd_t pmd; |
|
|
|
pmd = READ_ONCE(*pmdp); |
|
|
|
if (!pmd_table(pmd)) { |
|
VM_WARN_ON(1); |
|
return 1; |
|
} |
|
|
|
table = pte_offset_kernel(pmdp, addr); |
|
pmd_clear(pmdp); |
|
__flush_tlb_kernel_pgtable(addr); |
|
pte_free_kernel(NULL, table); |
|
return 1; |
|
} |
|
|
|
int pud_free_pmd_page(pud_t *pudp, unsigned long addr) |
|
{ |
|
pmd_t *table; |
|
pmd_t *pmdp; |
|
pud_t pud; |
|
unsigned long next, end; |
|
|
|
pud = READ_ONCE(*pudp); |
|
|
|
if (!pud_table(pud)) { |
|
VM_WARN_ON(1); |
|
return 1; |
|
} |
|
|
|
table = pmd_offset(pudp, addr); |
|
pmdp = table; |
|
next = addr; |
|
end = addr + PUD_SIZE; |
|
do { |
|
pmd_free_pte_page(pmdp, next); |
|
} while (pmdp++, next += PMD_SIZE, next != end); |
|
|
|
pud_clear(pudp); |
|
__flush_tlb_kernel_pgtable(addr); |
|
pmd_free(NULL, table); |
|
return 1; |
|
} |
|
|
|
#ifdef CONFIG_MEMORY_HOTPLUG |
|
static void __remove_pgd_mapping(pgd_t *pgdir, unsigned long start, u64 size) |
|
{ |
|
unsigned long end = start + size; |
|
|
|
WARN_ON(pgdir != init_mm.pgd); |
|
WARN_ON((start < PAGE_OFFSET) || (end > PAGE_END)); |
|
|
|
unmap_hotplug_range(start, end, false, NULL); |
|
free_empty_tables(start, end, PAGE_OFFSET, PAGE_END); |
|
} |
|
|
|
struct range arch_get_mappable_range(void) |
|
{ |
|
struct range mhp_range; |
|
u64 start_linear_pa = __pa(_PAGE_OFFSET(vabits_actual)); |
|
u64 end_linear_pa = __pa(PAGE_END - 1); |
|
|
|
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { |
|
/* |
|
* Check for a wrap, it is possible because of randomized linear |
|
* mapping the start physical address is actually bigger than |
|
* the end physical address. In this case set start to zero |
|
* because [0, end_linear_pa] range must still be able to cover |
|
* all addressable physical addresses. |
|
*/ |
|
if (start_linear_pa > end_linear_pa) |
|
start_linear_pa = 0; |
|
} |
|
|
|
WARN_ON(start_linear_pa > end_linear_pa); |
|
|
|
/* |
|
* Linear mapping region is the range [PAGE_OFFSET..(PAGE_END - 1)] |
|
* accommodating both its ends but excluding PAGE_END. Max physical |
|
* range which can be mapped inside this linear mapping range, must |
|
* also be derived from its end points. |
|
*/ |
|
mhp_range.start = start_linear_pa; |
|
mhp_range.end = end_linear_pa; |
|
|
|
return mhp_range; |
|
} |
|
|
|
int arch_add_memory(int nid, u64 start, u64 size, |
|
struct mhp_params *params) |
|
{ |
|
int ret, flags = NO_EXEC_MAPPINGS; |
|
|
|
VM_BUG_ON(!mhp_range_allowed(start, size, true)); |
|
|
|
/* |
|
* KFENCE requires linear map to be mapped at page granularity, so that |
|
* it is possible to protect/unprotect single pages in the KFENCE pool. |
|
*/ |
|
if (can_set_direct_map() || IS_ENABLED(CONFIG_KFENCE)) |
|
flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; |
|
|
|
__create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start), |
|
size, params->pgprot, __pgd_pgtable_alloc, |
|
flags); |
|
|
|
memblock_clear_nomap(start, size); |
|
|
|
ret = __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT, |
|
params); |
|
if (ret) |
|
__remove_pgd_mapping(swapper_pg_dir, |
|
__phys_to_virt(start), size); |
|
return ret; |
|
} |
|
|
|
void arch_remove_memory(int nid, u64 start, u64 size, |
|
struct vmem_altmap *altmap) |
|
{ |
|
unsigned long start_pfn = start >> PAGE_SHIFT; |
|
unsigned long nr_pages = size >> PAGE_SHIFT; |
|
|
|
__remove_pages(start_pfn, nr_pages, altmap); |
|
__remove_pgd_mapping(swapper_pg_dir, __phys_to_virt(start), size); |
|
} |
|
|
|
/* |
|
* This memory hotplug notifier helps prevent boot memory from being |
|
* inadvertently removed as it blocks pfn range offlining process in |
|
* __offline_pages(). Hence this prevents both offlining as well as |
|
* removal process for boot memory which is initially always online. |
|
* In future if and when boot memory could be removed, this notifier |
|
* should be dropped and free_hotplug_page_range() should handle any |
|
* reserved pages allocated during boot. |
|
*/ |
|
static int prevent_bootmem_remove_notifier(struct notifier_block *nb, |
|
unsigned long action, void *data) |
|
{ |
|
struct mem_section *ms; |
|
struct memory_notify *arg = data; |
|
unsigned long end_pfn = arg->start_pfn + arg->nr_pages; |
|
unsigned long pfn = arg->start_pfn; |
|
|
|
if ((action != MEM_GOING_OFFLINE) && (action != MEM_OFFLINE)) |
|
return NOTIFY_OK; |
|
|
|
for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { |
|
unsigned long start = PFN_PHYS(pfn); |
|
unsigned long end = start + (1UL << PA_SECTION_SHIFT); |
|
|
|
ms = __pfn_to_section(pfn); |
|
if (!early_section(ms)) |
|
continue; |
|
|
|
if (action == MEM_GOING_OFFLINE) { |
|
/* |
|
* Boot memory removal is not supported. Prevent |
|
* it via blocking any attempted offline request |
|
* for the boot memory and just report it. |
|
*/ |
|
pr_warn("Boot memory [%lx %lx] offlining attempted\n", start, end); |
|
return NOTIFY_BAD; |
|
} else if (action == MEM_OFFLINE) { |
|
/* |
|
* This should have never happened. Boot memory |
|
* offlining should have been prevented by this |
|
* very notifier. Probably some memory removal |
|
* procedure might have changed which would then |
|
* require further debug. |
|
*/ |
|
pr_err("Boot memory [%lx %lx] offlined\n", start, end); |
|
|
|
/* |
|
* Core memory hotplug does not process a return |
|
* code from the notifier for MEM_OFFLINE events. |
|
* The error condition has been reported. Return |
|
* from here as if ignored. |
|
*/ |
|
return NOTIFY_DONE; |
|
} |
|
} |
|
return NOTIFY_OK; |
|
} |
|
|
|
static struct notifier_block prevent_bootmem_remove_nb = { |
|
.notifier_call = prevent_bootmem_remove_notifier, |
|
}; |
|
|
|
/* |
|
* This ensures that boot memory sections on the platform are online |
|
* from early boot. Memory sections could not be prevented from being |
|
* offlined, unless for some reason they are not online to begin with. |
|
* This helps validate the basic assumption on which the above memory |
|
* event notifier works to prevent boot memory section offlining and |
|
* its possible removal. |
|
*/ |
|
static void validate_bootmem_online(void) |
|
{ |
|
phys_addr_t start, end, addr; |
|
struct mem_section *ms; |
|
u64 i; |
|
|
|
/* |
|
* Scanning across all memblock might be expensive |
|
* on some big memory systems. Hence enable this |
|
* validation only with DEBUG_VM. |
|
*/ |
|
if (!IS_ENABLED(CONFIG_DEBUG_VM)) |
|
return; |
|
|
|
for_each_mem_range(i, &start, &end) { |
|
for (addr = start; addr < end; addr += (1UL << PA_SECTION_SHIFT)) { |
|
ms = __pfn_to_section(PHYS_PFN(addr)); |
|
|
|
/* |
|
* All memory ranges in the system at this point |
|
* should have been marked as early sections. |
|
*/ |
|
WARN_ON(!early_section(ms)); |
|
|
|
/* |
|
* Memory notifier mechanism here to prevent boot |
|
* memory offlining depends on the fact that each |
|
* early section memory on the system is initially |
|
* online. Otherwise a given memory section which |
|
* is already offline will be overlooked and can |
|
* be removed completely. Call out such sections. |
|
*/ |
|
if (!online_section(ms)) |
|
pr_err("Boot memory [%llx %llx] is offline, can be removed\n", |
|
addr, addr + (1UL << PA_SECTION_SHIFT)); |
|
} |
|
} |
|
} |
|
|
|
static int __init prevent_bootmem_remove_init(void) |
|
{ |
|
int ret = 0; |
|
|
|
if (!IS_ENABLED(CONFIG_MEMORY_HOTREMOVE)) |
|
return ret; |
|
|
|
validate_bootmem_online(); |
|
ret = register_memory_notifier(&prevent_bootmem_remove_nb); |
|
if (ret) |
|
pr_err("%s: Notifier registration failed %d\n", __func__, ret); |
|
|
|
return ret; |
|
} |
|
early_initcall(prevent_bootmem_remove_init); |
|
#endif
|
|
|