forked from Minki/linux
d8a719059b
This reverts commitc742199a01
.c742199a01
("mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge") breaks arm64 in at least two ways for configurations where PUD or PMD folding occur: 1. We no longer install huge-vmap mappings and silently fall back to page-granular entries, despite being able to install block entries at what is effectively the PGD level. 2. If the linear map is backed with block mappings, these will now silently fail to be created in alloc_init_pud(), causing a panic early during boot. The pgtable selftests caught this, although a fix has not been forthcoming and Christophe is AWOL at the moment, so just revert the change for now to get a working -rc3 on which we can queue patches for 5.15. A simple revert breaks the build for 32-bit PowerPC 8xx machines, which rely on the default function definitions when the corresponding page-table levels are folded, since commita6a8f7c4aa
("powerpc/8xx: add support for huge pages on VMAP and VMALLOC"), eg: powerpc64-linux-ld: mm/vmalloc.o: in function `vunmap_pud_range': linux/mm/vmalloc.c:362: undefined reference to `pud_clear_huge' To avoid that, add stubs for pud_clear_huge() and pmd_clear_huge() in arch/powerpc/mm/nohash/8xx.c as suggested by Christophe. Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Fixes:c742199a01
("mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge") Signed-off-by: Jonathan Marek <jonathan@marek.ca> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Marc Zyngier <maz@kernel.org> [mpe: Fold in 8xx.c changes from Christophe and mention in change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/linux-arm-kernel/CAMuHMdXShORDox-xxaeUfDW3wx2PeggFSqhVSHVZNKCGK-y_vQ@mail.gmail.com/ Link: https://lore.kernel.org/r/20210717160118.9855-1-jonathan@marek.ca Link: https://lore.kernel.org/r/87r1fs1762.fsf@mpe.ellerman.id.au Signed-off-by: Will Deacon <will@kernel.org>
1640 lines
43 KiB
C
1640 lines
43 KiB
C
// 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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#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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/* 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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* 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)(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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* 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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/* 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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* 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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* 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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if (page_mappings_only)
|
|
flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
|
|
|
|
__create_pgd_mapping(mm->pgd, phys, virt, size, prot,
|
|
pgd_pgtable_alloc, flags);
|
|
}
|
|
|
|
static void update_mapping_prot(phys_addr_t phys, unsigned long virt,
|
|
phys_addr_t size, pgprot_t prot)
|
|
{
|
|
if ((virt >= PAGE_END) && (virt < VMALLOC_START)) {
|
|
pr_warn("BUG: not updating mapping for %pa at 0x%016lx - outside kernel range\n",
|
|
&phys, virt);
|
|
return;
|
|
}
|
|
|
|
__create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL,
|
|
NO_CONT_MAPPINGS);
|
|
|
|
/* flush the TLBs after updating live kernel mappings */
|
|
flush_tlb_kernel_range(virt, virt + size);
|
|
}
|
|
|
|
static void __init __map_memblock(pgd_t *pgdp, phys_addr_t start,
|
|
phys_addr_t end, pgprot_t prot, int flags)
|
|
{
|
|
__create_pgd_mapping(pgdp, start, __phys_to_virt(start), end - start,
|
|
prot, early_pgtable_alloc, flags);
|
|
}
|
|
|
|
void __init mark_linear_text_alias_ro(void)
|
|
{
|
|
/*
|
|
* Remove the write permissions from the linear alias of .text/.rodata
|
|
*/
|
|
update_mapping_prot(__pa_symbol(_stext), (unsigned long)lm_alias(_stext),
|
|
(unsigned long)__init_begin - (unsigned long)_stext,
|
|
PAGE_KERNEL_RO);
|
|
}
|
|
|
|
static bool crash_mem_map __initdata;
|
|
|
|
static int __init enable_crash_mem_map(char *arg)
|
|
{
|
|
/*
|
|
* Proper parameter parsing is done by reserve_crashkernel(). We only
|
|
* need to know if the linear map has to avoid block mappings so that
|
|
* the crashkernel reservations can be unmapped later.
|
|
*/
|
|
crash_mem_map = true;
|
|
|
|
return 0;
|
|
}
|
|
early_param("crashkernel", enable_crash_mem_map);
|
|
|
|
static void __init map_mem(pgd_t *pgdp)
|
|
{
|
|
static const u64 direct_map_end = _PAGE_END(VA_BITS_MIN);
|
|
phys_addr_t kernel_start = __pa_symbol(_stext);
|
|
phys_addr_t kernel_end = __pa_symbol(__init_begin);
|
|
phys_addr_t start, end;
|
|
int flags = NO_EXEC_MAPPINGS;
|
|
u64 i;
|
|
|
|
/*
|
|
* Setting hierarchical PXNTable attributes on table entries covering
|
|
* the linear region is only possible if it is guaranteed that no table
|
|
* entries at any level are being shared between the linear region and
|
|
* the vmalloc region. Check whether this is true for the PGD level, in
|
|
* which case it is guaranteed to be true for all other levels as well.
|
|
*/
|
|
BUILD_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end));
|
|
|
|
if (can_set_direct_map() || crash_mem_map || IS_ENABLED(CONFIG_KFENCE))
|
|
flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
|
|
|
|
/*
|
|
* Take care not to create a writable alias for the
|
|
* read-only text and rodata sections of the kernel image.
|
|
* So temporarily mark them as NOMAP to skip mappings in
|
|
* the following for-loop
|
|
*/
|
|
memblock_mark_nomap(kernel_start, kernel_end - kernel_start);
|
|
|
|
/* map all the memory banks */
|
|
for_each_mem_range(i, &start, &end) {
|
|
if (start >= end)
|
|
break;
|
|
/*
|
|
* The linear map must allow allocation tags reading/writing
|
|
* if MTE is present. Otherwise, it has the same attributes as
|
|
* PAGE_KERNEL.
|
|
*/
|
|
__map_memblock(pgdp, start, end, pgprot_tagged(PAGE_KERNEL),
|
|
flags);
|
|
}
|
|
|
|
/*
|
|
* 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
|