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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Based on arch/arm/mm/mmu.c
- *
- * Copyright (C) 1995-2005 Russell King
- * Copyright (C) 2012 ARM Ltd.
- */
- #include <linux/cache.h>
- #include <linux/export.h>
- #include <linux/kernel.h>
- #include <linux/errno.h>
- #include <linux/init.h>
- #include <linux/ioport.h>
- #include <linux/kexec.h>
- #include <linux/libfdt.h>
- #include <linux/mman.h>
- #include <linux/nodemask.h>
- #include <linux/memblock.h>
- #include <linux/memory.h>
- #include <linux/fs.h>
- #include <linux/io.h>
- #include <linux/mm.h>
- #include <linux/vmalloc.h>
- #include <asm/barrier.h>
- #include <asm/cputype.h>
- #include <asm/fixmap.h>
- #include <asm/kasan.h>
- #include <asm/kernel-pgtable.h>
- #include <asm/sections.h>
- #include <asm/setup.h>
- #include <linux/sizes.h>
- #include <asm/tlb.h>
- #include <asm/mmu_context.h>
- #include <asm/ptdump.h>
- #include <asm/tlbflush.h>
- #include <asm/pgalloc.h>
- #define NO_BLOCK_MAPPINGS BIT(0)
- #define NO_CONT_MAPPINGS BIT(1)
- u64 idmap_t0sz = TCR_T0SZ(VA_BITS_MIN);
- u64 idmap_ptrs_per_pgd = PTRS_PER_PGD;
- u64 __section(".mmuoff.data.write") vabits_actual;
- EXPORT_SYMBOL(vabits_actual);
- u64 kimage_voffset __ro_after_init;
- EXPORT_SYMBOL(kimage_voffset);
- /*
- * Empty_zero_page is a special page that is used for zero-initialized data
- * and COW.
- */
- unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
- EXPORT_SYMBOL(empty_zero_page);
- static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss;
- static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss __maybe_unused;
- static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss __maybe_unused;
- static DEFINE_SPINLOCK(swapper_pgdir_lock);
- static DEFINE_MUTEX(fixmap_lock);
- void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd)
- {
- pgd_t *fixmap_pgdp;
- spin_lock(&swapper_pgdir_lock);
- fixmap_pgdp = pgd_set_fixmap(__pa_symbol(pgdp));
- WRITE_ONCE(*fixmap_pgdp, pgd);
- /*
- * We need dsb(ishst) here to ensure the page-table-walker sees
- * our new entry before set_p?d() returns. The fixmap's
- * flush_tlb_kernel_range() via clear_fixmap() does this for us.
- */
- pgd_clear_fixmap();
- spin_unlock(&swapper_pgdir_lock);
- }
- pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
- unsigned long size, pgprot_t vma_prot)
- {
- if (!pfn_valid(pfn))
- return pgprot_noncached(vma_prot);
- else if (file->f_flags & O_SYNC)
- return pgprot_writecombine(vma_prot);
- return vma_prot;
- }
- EXPORT_SYMBOL(phys_mem_access_prot);
- static phys_addr_t __init early_pgtable_alloc(int shift)
- {
- phys_addr_t phys;
- void *ptr;
- phys = memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
- if (!phys)
- panic("Failed to allocate page table page\n");
- /*
- * The FIX_{PGD,PUD,PMD} slots may be in active use, but the FIX_PTE
- * slot will be free, so we can (ab)use the FIX_PTE slot to initialise
- * any level of table.
- */
- ptr = pte_set_fixmap(phys);
- memset(ptr, 0, PAGE_SIZE);
- /*
- * Implicit barriers also ensure the zeroed page is visible to the page
- * table walker
- */
- pte_clear_fixmap();
- return phys;
- }
- static bool pgattr_change_is_safe(u64 old, u64 new)
- {
- /*
- * The following mapping attributes may be updated in live
- * kernel mappings without the need for break-before-make.
- */
- pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE | PTE_NG;
- /* creating or taking down mappings is always safe */
- if (old == 0 || new == 0)
- return true;
- /* live contiguous mappings may not be manipulated at all */
- if ((old | new) & PTE_CONT)
- return false;
- /* Transitioning from Non-Global to Global is unsafe */
- if (old & ~new & PTE_NG)
- return false;
- /*
- * Changing the memory type between Normal and Normal-Tagged is safe
- * since Tagged is considered a permission attribute from the
- * mismatched attribute aliases perspective.
- */
- if (((old & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL) ||
- (old & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL_TAGGED)) &&
- ((new & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL) ||
- (new & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL_TAGGED)))
- mask |= PTE_ATTRINDX_MASK;
- return ((old ^ new) & ~mask) == 0;
- }
- static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end,
- phys_addr_t phys, pgprot_t prot)
- {
- pte_t *ptep;
- ptep = pte_set_fixmap_offset(pmdp, addr);
- do {
- pte_t old_pte = READ_ONCE(*ptep);
- set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot));
- /*
- * After the PTE entry has been populated once, we
- * only allow updates to the permission attributes.
- */
- BUG_ON(!pgattr_change_is_safe(pte_val(old_pte),
- READ_ONCE(pte_val(*ptep))));
- phys += PAGE_SIZE;
- } while (ptep++, addr += PAGE_SIZE, addr != end);
- pte_clear_fixmap();
- }
- static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr,
- unsigned long end, phys_addr_t phys,
- pgprot_t prot,
- phys_addr_t (*pgtable_alloc)(int),
- int flags)
- {
- unsigned long next;
- pmd_t pmd = READ_ONCE(*pmdp);
- BUG_ON(pmd_sect(pmd));
- if (pmd_none(pmd)) {
- phys_addr_t pte_phys;
- BUG_ON(!pgtable_alloc);
- pte_phys = pgtable_alloc(PAGE_SHIFT);
- __pmd_populate(pmdp, pte_phys, PMD_TYPE_TABLE);
- pmd = READ_ONCE(*pmdp);
- }
- BUG_ON(pmd_bad(pmd));
- do {
- pgprot_t __prot = prot;
- next = pte_cont_addr_end(addr, end);
- /* use a contiguous mapping if the range is suitably aligned */
- if ((((addr | next | phys) & ~CONT_PTE_MASK) == 0) &&
- (flags & NO_CONT_MAPPINGS) == 0)
- __prot = __pgprot(pgprot_val(prot) | PTE_CONT);
- init_pte(pmdp, addr, next, phys, __prot);
- phys += next - addr;
- } while (addr = next, addr != end);
- }
- static void init_pmd(pud_t *pudp, unsigned long addr, unsigned long end,
- phys_addr_t phys, pgprot_t prot,
- phys_addr_t (*pgtable_alloc)(int), int flags)
- {
- unsigned long next;
- pmd_t *pmdp;
- pmdp = pmd_set_fixmap_offset(pudp, addr);
- do {
- pmd_t old_pmd = READ_ONCE(*pmdp);
- next = pmd_addr_end(addr, end);
- /* try section mapping first */
- if (((addr | next | phys) & ~SECTION_MASK) == 0 &&
- (flags & NO_BLOCK_MAPPINGS) == 0) {
- pmd_set_huge(pmdp, phys, prot);
- /*
- * After the PMD entry has been populated once, we
- * only allow updates to the permission attributes.
- */
- BUG_ON(!pgattr_change_is_safe(pmd_val(old_pmd),
- READ_ONCE(pmd_val(*pmdp))));
- } else {
- alloc_init_cont_pte(pmdp, addr, next, phys, prot,
- pgtable_alloc, flags);
- BUG_ON(pmd_val(old_pmd) != 0 &&
- pmd_val(old_pmd) != READ_ONCE(pmd_val(*pmdp)));
- }
- phys += next - addr;
- } while (pmdp++, addr = next, addr != end);
- pmd_clear_fixmap();
- }
- static void alloc_init_cont_pmd(pud_t *pudp, unsigned long addr,
- unsigned long end, phys_addr_t phys,
- pgprot_t prot,
- phys_addr_t (*pgtable_alloc)(int), int flags)
- {
- unsigned long next;
- pud_t pud = READ_ONCE(*pudp);
- /*
- * Check for initial section mappings in the pgd/pud.
- */
- BUG_ON(pud_sect(pud));
- if (pud_none(pud)) {
- phys_addr_t pmd_phys;
- BUG_ON(!pgtable_alloc);
- pmd_phys = pgtable_alloc(PMD_SHIFT);
- __pud_populate(pudp, pmd_phys, PUD_TYPE_TABLE);
- pud = READ_ONCE(*pudp);
- }
- BUG_ON(pud_bad(pud));
- do {
- pgprot_t __prot = prot;
- next = pmd_cont_addr_end(addr, end);
- /* use a contiguous mapping if the range is suitably aligned */
- if ((((addr | next | phys) & ~CONT_PMD_MASK) == 0) &&
- (flags & NO_CONT_MAPPINGS) == 0)
- __prot = __pgprot(pgprot_val(prot) | PTE_CONT);
- init_pmd(pudp, addr, next, phys, __prot, pgtable_alloc, flags);
- phys += next - addr;
- } while (addr = next, addr != end);
- }
- static inline bool use_1G_block(unsigned long addr, unsigned long next,
- unsigned long phys)
- {
- if (PAGE_SHIFT != 12)
- return false;
- if (((addr | next | phys) & ~PUD_MASK) != 0)
- return false;
- return true;
- }
- static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
- phys_addr_t phys, pgprot_t prot,
- phys_addr_t (*pgtable_alloc)(int),
- int flags)
- {
- unsigned long next;
- pud_t *pudp;
- p4d_t *p4dp = p4d_offset(pgdp, addr);
- p4d_t p4d = READ_ONCE(*p4dp);
- if (p4d_none(p4d)) {
- phys_addr_t pud_phys;
- BUG_ON(!pgtable_alloc);
- pud_phys = pgtable_alloc(PUD_SHIFT);
- __p4d_populate(p4dp, pud_phys, PUD_TYPE_TABLE);
- p4d = READ_ONCE(*p4dp);
- }
- BUG_ON(p4d_bad(p4d));
- /*
- * No need for locking during early boot. And it doesn't work as
- * expected with KASLR enabled.
- */
- if (system_state != SYSTEM_BOOTING)
- mutex_lock(&fixmap_lock);
- pudp = pud_set_fixmap_offset(p4dp, addr);
- do {
- pud_t old_pud = READ_ONCE(*pudp);
- next = pud_addr_end(addr, end);
- /*
- * For 4K granule only, attempt to put down a 1GB block
- */
- if (use_1G_block(addr, next, phys) &&
- (flags & NO_BLOCK_MAPPINGS) == 0) {
- pud_set_huge(pudp, phys, prot);
- /*
- * After the PUD entry has been populated once, we
- * only allow updates to the permission attributes.
- */
- BUG_ON(!pgattr_change_is_safe(pud_val(old_pud),
- READ_ONCE(pud_val(*pudp))));
- } else {
- alloc_init_cont_pmd(pudp, addr, next, phys, prot,
- pgtable_alloc, flags);
- BUG_ON(pud_val(old_pud) != 0 &&
- pud_val(old_pud) != READ_ONCE(pud_val(*pudp)));
- }
- phys += next - addr;
- } while (pudp++, addr = next, addr != end);
- pud_clear_fixmap();
- if (system_state != SYSTEM_BOOTING)
- mutex_unlock(&fixmap_lock);
- }
- static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
- unsigned long virt, phys_addr_t size,
- pgprot_t prot,
- phys_addr_t (*pgtable_alloc)(int),
- int flags)
- {
- unsigned long addr, end, next;
- pgd_t *pgdp = pgd_offset_pgd(pgdir, virt);
- /*
- * If the virtual and physical address don't have the same offset
- * within a page, we cannot map the region as the caller expects.
- */
- if (WARN_ON((phys ^ virt) & ~PAGE_MASK))
- return;
- phys &= PAGE_MASK;
- addr = virt & PAGE_MASK;
- end = PAGE_ALIGN(virt + size);
- do {
- next = pgd_addr_end(addr, end);
- alloc_init_pud(pgdp, addr, next, phys, prot, pgtable_alloc,
- flags);
- phys += next - addr;
- } while (pgdp++, addr = next, addr != end);
- }
- static phys_addr_t __pgd_pgtable_alloc(int shift)
- {
- void *ptr = (void *)__get_free_page(GFP_PGTABLE_KERNEL);
- BUG_ON(!ptr);
- /* Ensure the zeroed page is visible to the page table walker */
- dsb(ishst);
- return __pa(ptr);
- }
- static phys_addr_t pgd_pgtable_alloc(int shift)
- {
- phys_addr_t pa = __pgd_pgtable_alloc(shift);
- /*
- * Call proper page table ctor in case later we need to
- * call core mm functions like apply_to_page_range() on
- * this pre-allocated page table.
- *
- * We don't select ARCH_ENABLE_SPLIT_PMD_PTLOCK if pmd is
- * folded, and if so pgtable_pmd_page_ctor() becomes nop.
- */
- if (shift == PAGE_SHIFT)
- BUG_ON(!pgtable_pte_page_ctor(phys_to_page(pa)));
- else if (shift == PMD_SHIFT)
- BUG_ON(!pgtable_pmd_page_ctor(phys_to_page(pa)));
- return pa;
- }
- /*
- * This function can only be used to modify existing table entries,
- * without allocating new levels of table. Note that this permits the
- * creation of new section or page entries.
- */
- static void __init create_mapping_noalloc(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 creating 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);
- }
- void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
- unsigned long virt, phys_addr_t size,
- pgprot_t prot, bool page_mappings_only)
- {
- int flags = 0;
- BUG_ON(mm == &init_mm);
- 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(_text), (unsigned long)lm_alias(_text),
- (unsigned long)__init_begin - (unsigned long)_text,
- 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)
- {
- phys_addr_t kernel_start = __pa_symbol(_text);
- phys_addr_t kernel_end = __pa_symbol(__init_begin);
- phys_addr_t start, end;
- int flags = 0;
- u64 i;
- if (rodata_full || debug_pagealloc_enabled() ||
- 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);
- #ifdef CONFIG_KEXEC_CORE
- if (crash_mem_map) {
- if (IS_ENABLED(CONFIG_ZONE_DMA) ||
- IS_ENABLED(CONFIG_ZONE_DMA32))
- flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
- else if (crashk_res.end)
- memblock_mark_nomap(crashk_res.start,
- resource_size(&crashk_res));
- }
- #endif
- /* 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 [_text, __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);
- /*
- * Use page-level mappings here so that we can shrink the region
- * in page granularity and put back unused memory to buddy system
- * through /sys/kernel/kexec_crash_size interface.
- */
- #ifdef CONFIG_KEXEC_CORE
- if (crash_mem_map &&
- !IS_ENABLED(CONFIG_ZONE_DMA) && !IS_ENABLED(CONFIG_ZONE_DMA32)) {
- if (crashk_res.end) {
- __map_memblock(pgdp, crashk_res.start,
- crashk_res.end + 1,
- PAGE_KERNEL,
- NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS);
- memblock_clear_nomap(crashk_res.start,
- resource_size(&crashk_res));
- }
- }
- #endif
- }
- 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)
- {
- int i;
- 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,
- entry_tramp_text_size(), prot,
- __pgd_pgtable_alloc, NO_BLOCK_MAPPINGS);
- /* Map both the text and data into the kernel page table */
- for (i = 0; i < DIV_ROUND_UP(entry_tramp_text_size(), PAGE_SIZE); i++)
- __set_fixmap(FIX_ENTRY_TRAMP_TEXT1 - i,
- pa_start + i * PAGE_SIZE, 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, _text, _etext, text_prot, &vmlinux_text, 0,
- VM_NO_GUARD);
- map_kernel_segment(pgdp, __start_rodata, __inittext_begin, PAGE_KERNEL,
- &vmlinux_rodata, NO_CONT_MAPPINGS, VM_NO_GUARD);
- map_kernel_segment(pgdp, __inittext_begin, __inittext_end, text_prot,
- &vmlinux_inittext, 0, VM_NO_GUARD);
- map_kernel_segment(pgdp, __initdata_begin, __initdata_end, PAGE_KERNEL,
- &vmlinux_initdata, 0, VM_NO_GUARD);
- map_kernel_segment(pgdp, _data, _end, PAGE_KERNEL, &vmlinux_data, 0, 0);
- if (!READ_ONCE(pgd_val(*pgd_offset_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
- #ifdef CONFIG_SPARSEMEM_VMEMMAP
- #if !ARM64_SWAPPER_USES_SECTION_MAPS
- int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
- struct vmem_altmap *altmap)
- {
- return vmemmap_populate_basepages(start, end, node, altmap);
- }
- #else /* !ARM64_SWAPPER_USES_SECTION_MAPS */
- int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
- struct vmem_altmap *altmap)
- {
- unsigned long addr = start;
- unsigned long next;
- pgd_t *pgdp;
- p4d_t *p4dp;
- pud_t *pudp;
- pmd_t *pmdp;
- 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_SWAPPER_USES_SECTION_MAPS */
- void vmemmap_free(unsigned long start, unsigned long end,
- struct vmem_altmap *altmap)
- {
- #ifdef CONFIG_MEMORY_HOTPLUG
- 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
- }
- #endif /* CONFIG_SPARSEMEM_VMEMMAP */
- 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), PUD_TYPE_TABLE);
- pudp = fixmap_pud(addr);
- }
- if (pud_none(READ_ONCE(*pudp)))
- __pud_populate(pudp, __pa_symbol(bm_pmd), PMD_TYPE_TABLE);
- pmdp = fixmap_pmd(addr);
- __pmd_populate(pmdp, __pa_symbol(bm_pte), PMD_TYPE_TABLE);
- /*
- * The boot-ioremap range spans multiple pmds, for which
- * we are not prepared:
- */
- BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
- != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
- if ((pmdp != fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)))
- || pmdp != fixmap_pmd(fix_to_virt(FIX_BTMAP_END))) {
- WARN_ON(1);
- pr_warn("pmdp %p != %p, %p\n",
- pmdp, fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)),
- fixmap_pmd(fix_to_virt(FIX_BTMAP_END)));
- pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
- fix_to_virt(FIX_BTMAP_BEGIN));
- pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n",
- fix_to_virt(FIX_BTMAP_END));
- pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
- pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN);
- }
- }
- /*
- * Unusually, this is also called in IRQ context (ghes_iounmap_irq) so if we
- * ever need to use IPIs for TLB broadcasting, then we're in trouble here.
- */
- void __set_fixmap(enum fixed_addresses idx,
- phys_addr_t phys, pgprot_t flags)
- {
- unsigned long addr = __fix_to_virt(idx);
- pte_t *ptep;
- BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
- ptep = fixmap_pte(addr);
- if (pgprot_val(flags)) {
- set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, flags));
- } else {
- pte_clear(&init_mm, addr, ptep);
- flush_tlb_kernel_range(addr, addr+PAGE_SIZE);
- }
- }
- void *__init fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
- {
- const u64 dt_virt_base = __fix_to_virt(FIX_FDT);
- int offset;
- void *dt_virt;
- /*
- * Check whether the physical FDT address is set and meets the minimum
- * alignment requirement. Since we are relying on MIN_FDT_ALIGN to be
- * at least 8 bytes so that we can always access the magic and size
- * fields of the FDT header after mapping the first chunk, double check
- * here if that is indeed the case.
- */
- BUILD_BUG_ON(MIN_FDT_ALIGN < 8);
- if (!dt_phys || dt_phys % MIN_FDT_ALIGN)
- return NULL;
- /*
- * Make sure that the FDT region can be mapped without the need to
- * allocate additional translation table pages, so that it is safe
- * to call create_mapping_noalloc() this early.
- *
- * On 64k pages, the FDT will be mapped using PTEs, so we need to
- * be in the same PMD as the rest of the fixmap.
- * On 4k pages, we'll use section mappings for the FDT so we only
- * have to be in the same PUD.
- */
- BUILD_BUG_ON(dt_virt_base % SZ_2M);
- BUILD_BUG_ON(__fix_to_virt(FIX_FDT_END) >> SWAPPER_TABLE_SHIFT !=
- __fix_to_virt(FIX_BTMAP_BEGIN) >> SWAPPER_TABLE_SHIFT);
- offset = dt_phys % SWAPPER_BLOCK_SIZE;
- dt_virt = (void *)dt_virt_base + offset;
- /* map the first chunk so we can read the size from the header */
- create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE),
- dt_virt_base, SWAPPER_BLOCK_SIZE, prot);
- if (fdt_magic(dt_virt) != FDT_MAGIC)
- return NULL;
- *size = fdt_totalsize(dt_virt);
- if (*size > MAX_FDT_SIZE)
- return NULL;
- if (offset + *size > SWAPPER_BLOCK_SIZE)
- create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE), dt_virt_base,
- round_up(offset + *size, SWAPPER_BLOCK_SIZE), prot);
- return dt_virt;
- }
- int __init arch_ioremap_p4d_supported(void)
- {
- return 0;
- }
- int __init arch_ioremap_pud_supported(void)
- {
- /*
- * Only 4k granule supports level 1 block mappings.
- * SW table walks can't handle removal of intermediate entries.
- */
- return IS_ENABLED(CONFIG_ARM64_4K_PAGES) &&
- !IS_ENABLED(CONFIG_PTDUMP_DEBUGFS);
- }
- int __init arch_ioremap_pmd_supported(void)
- {
- /* See arch_ioremap_pud_supported() */
- return !IS_ENABLED(CONFIG_PTDUMP_DEBUGFS);
- }
- 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;
- }
- int p4d_free_pud_page(p4d_t *p4d, unsigned long addr)
- {
- return 0; /* Don't attempt a block mapping */
- }
- #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);
- }
- static bool inside_linear_region(u64 start, u64 size)
- {
- 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.
- */
- return start >= start_linear_pa && (start + size - 1) <= end_linear_pa;
- }
- int arch_add_memory(int nid, u64 start, u64 size,
- struct mhp_params *params)
- {
- int ret, flags = 0;
- if (!inside_linear_region(start, size)) {
- pr_err("[%llx %llx] is outside linear mapping region\n", start, start + size);
- return -EINVAL;
- }
- /*
- * 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 (rodata_full || debug_pagealloc_enabled() ||
- 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);
- else {
- max_pfn = PFN_UP(start + size);
- max_low_pfn = max_pfn;
- }
- 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);
- }
- int check_range_driver_managed(u64 start, u64 size, const char *resource_name)
- {
- struct mem_section *ms;
- unsigned long pfn = __phys_to_pfn(start);
- unsigned long end_pfn = __phys_to_pfn(start + size);
- struct resource *res;
- unsigned long flags;
- res = lookup_resource(&iomem_resource, start);
- if (!res) {
- pr_err("%s: couldn't find memory resource for start 0x%llx\n",
- __func__, start);
- return -EINVAL;
- }
- flags = res->flags;
- if (!(flags & IORESOURCE_SYSRAM_DRIVER_MANAGED) ||
- strstr(resource_name, "System RAM (") != resource_name)
- return -EINVAL;
- for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
- ms = __pfn_to_section(pfn);
- if (early_section(ms))
- return -EINVAL;
- }
- return 0;
- }
- int populate_range_driver_managed(u64 start, u64 size,
- const char *resource_name)
- {
- unsigned long virt = (unsigned long)phys_to_virt(start);
- int flags = 0;
- if (check_range_driver_managed(start, size, resource_name))
- return -EINVAL;
- /*
- * When rodata_full is enabled, memory is mapped at page size granule,
- * as opposed to block mapping.
- */
- if (rodata_full || debug_pagealloc_enabled())
- flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
- __create_pgd_mapping(init_mm.pgd, start, virt, size,
- PAGE_KERNEL, NULL, flags);
- return 0;
- }
- EXPORT_SYMBOL_GPL(populate_range_driver_managed);
- int depopulate_range_driver_managed(u64 start, u64 size,
- const char *resource_name)
- {
- if (check_range_driver_managed(start, size, resource_name))
- return -EINVAL;
- unmap_hotplug_range(start, start + size, false, NULL);
- return 0;
- }
- EXPORT_SYMBOL_GPL(depopulate_range_driver_managed);
- /*
- * 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)
- return NOTIFY_OK;
- for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
- ms = __pfn_to_section(pfn);
- if (early_section(ms))
- return NOTIFY_BAD;
- }
- return NOTIFY_OK;
- }
- static struct notifier_block prevent_bootmem_remove_nb = {
- .notifier_call = prevent_bootmem_remove_notifier,
- };
- static int __init prevent_bootmem_remove_init(void)
- {
- return register_memory_notifier(&prevent_bootmem_remove_nb);
- }
- device_initcall(prevent_bootmem_remove_init);
- #endif
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