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Diffstat (limited to 'arch/arm64/mm/mmu.c')
| -rw-r--r-- | arch/arm64/mm/mmu.c | 1041 |
1 files changed, 1041 insertions, 0 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c new file mode 100644 index 000000000..b0a83dbed --- /dev/null +++ b/arch/arm64/mm/mmu.c @@ -0,0 +1,1041 @@ +/* + * Based on arch/arm/mm/mmu.c + * + * Copyright (C) 1995-2005 Russell King + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/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/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 <asm/sizes.h> +#include <asm/tlb.h> +#include <asm/memblock.h> +#include <asm/mmu_context.h> +#include <asm/ptdump.h> +#include <asm/tlbflush.h> + +#define NO_BLOCK_MAPPINGS BIT(0) +#define NO_CONT_MAPPINGS BIT(1) + +u64 idmap_t0sz = TCR_T0SZ(VA_BITS); +u64 idmap_ptrs_per_pgd = PTRS_PER_PGD; + +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; + +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(void) +{ + phys_addr_t phys; + void *ptr; + + phys = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + + /* + * 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. + */ + static const 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; + + 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)(void), + 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(); + __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)(void), 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)(void), 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(); + __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)(void), + int flags) +{ + unsigned long next; + pud_t *pudp; + pgd_t pgd = READ_ONCE(*pgdp); + + if (pgd_none(pgd)) { + phys_addr_t pud_phys; + BUG_ON(!pgtable_alloc); + pud_phys = pgtable_alloc(); + __pgd_populate(pgdp, pud_phys, PUD_TYPE_TABLE); + pgd = READ_ONCE(*pgdp); + } + BUG_ON(pgd_bad(pgd)); + + pudp = pud_set_fixmap_offset(pgdp, 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(); +} + +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)(void), + int flags) +{ + unsigned long addr, length, end, next; + pgd_t *pgdp = pgd_offset_raw(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; + length = PAGE_ALIGN(size + (virt & ~PAGE_MASK)); + + end = addr + length; + 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(void) +{ + void *ptr = (void *)__get_free_page(PGALLOC_GFP); + if (!ptr || !pgtable_page_ctor(virt_to_page(ptr))) + BUG(); + + /* Ensure the zeroed page is visible to the page table walker */ + dsb(ishst); + return __pa(ptr); +} + +/* + * 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 < 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 < 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 void __init map_mem(pgd_t *pgdp) +{ + phys_addr_t kernel_start = __pa_symbol(_text); + phys_addr_t kernel_end = __pa_symbol(__init_begin); + struct memblock_region *reg; + int flags = 0; + + if (debug_pagealloc_enabled()) + 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 (crashk_res.end) + memblock_mark_nomap(crashk_res.start, + resource_size(&crashk_res)); +#endif + + /* map all the memory banks */ + for_each_memblock(memory, reg) { + phys_addr_t start = reg->base; + phys_addr_t end = start + reg->size; + + if (start >= end) + break; + if (memblock_is_nomap(reg)) + continue; + + __map_memblock(pgdp, start, end, 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); + +#ifdef CONFIG_KEXEC_CORE + /* + * 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. + */ + 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) +{ + return strtobool(arg, &rodata_enabled); +} +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, + 0); + + /* 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 + +/* + * Create fine-grained mappings for the kernel. + */ +static void __init map_kernel(pgd_t *pgdp) +{ + static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_inittext, + vmlinux_initdata, vmlinux_data; + + /* + * External debuggers may need to write directly to the text + * mapping to install SW breakpoints. Allow this (only) when + * explicitly requested with rodata=off. + */ + pgprot_t text_prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC; + + /* + * Only rodata will be remapped with different permissions later on, + * all other segments are allowed to use contiguous mappings. + */ + map_kernel_segment(pgdp, _text, _etext, text_prot, &vmlinux_text, 0, + VM_NO_GUARD); + map_kernel_segment(pgdp, __start_rodata, __inittext_begin, PAGE_KERNEL, + &vmlinux_rodata, NO_CONT_MAPPINGS, VM_NO_GUARD); + map_kernel_segment(pgdp, __inittext_begin, __inittext_end, text_prot, + &vmlinux_inittext, 0, VM_NO_GUARD); + map_kernel_segment(pgdp, __initdata_begin, __initdata_end, PAGE_KERNEL, + &vmlinux_initdata, 0, VM_NO_GUARD); + map_kernel_segment(pgdp, _data, _end, PAGE_KERNEL, &vmlinux_data, 0, 0); + + if (!READ_ONCE(pgd_val(*pgd_offset_raw(pgdp, FIXADDR_START)))) { + /* + * The fixmap falls in a separate pgd to the kernel, and doesn't + * live in the carveout for the swapper_pg_dir. We can simply + * re-use the existing dir for the fixmap. + */ + set_pgd(pgd_offset_raw(pgdp, FIXADDR_START), + READ_ONCE(*pgd_offset_k(FIXADDR_START))); + } else if (CONFIG_PGTABLE_LEVELS > 3) { + /* + * The fixmap shares its top level pgd entry with the kernel + * mapping. This can really only occur when we are running + * with 16k/4 levels, so we can simply reuse the pud level + * entry instead. + */ + BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES)); + pud_populate(&init_mm, + pud_set_fixmap_offset(pgdp, FIXADDR_START), + lm_alias(bm_pmd)); + pud_clear_fixmap(); + } else { + BUG(); + } + + kasan_copy_shadow(pgdp); +} + +/* + * paging_init() sets up the page tables, initialises the zone memory + * maps and sets up the zero page. + */ +void __init paging_init(void) +{ + phys_addr_t pgd_phys = early_pgtable_alloc(); + pgd_t *pgdp = pgd_set_fixmap(pgd_phys); + + map_kernel(pgdp); + map_mem(pgdp); + + /* + * We want to reuse the original swapper_pg_dir so we don't have to + * communicate the new address to non-coherent secondaries in + * secondary_entry, and so cpu_switch_mm can generate the address with + * adrp+add rather than a load from some global variable. + * + * To do this we need to go via a temporary pgd. + */ + cpu_replace_ttbr1(__va(pgd_phys)); + memcpy(swapper_pg_dir, pgdp, PGD_SIZE); + cpu_replace_ttbr1(lm_alias(swapper_pg_dir)); + + pgd_clear_fixmap(); + memblock_free(pgd_phys, PAGE_SIZE); + + /* + * We only reuse the PGD from the swapper_pg_dir, not the pud + pmd + * allocated with it. + */ + memblock_free(__pa_symbol(swapper_pg_dir) + PAGE_SIZE, + __pa_symbol(swapper_pg_end) - __pa_symbol(swapper_pg_dir) + - PAGE_SIZE); +} + +/* + * Check whether a kernel address is valid (derived from arch/x86/). + */ +int kern_addr_valid(unsigned long addr) +{ + pgd_t *pgdp; + pud_t *pudp, pud; + pmd_t *pmdp, pmd; + pte_t *ptep, pte; + + if ((((long)addr) >> VA_BITS) != -1UL) + return 0; + + pgdp = pgd_offset_k(addr); + if (pgd_none(READ_ONCE(*pgdp))) + return 0; + + pudp = pud_offset(pgdp, addr); + pud = READ_ONCE(*pudp); + if (pud_none(pud)) + return 0; + + if (pud_sect(pud)) + return pfn_valid(pud_pfn(pud)); + + pmdp = pmd_offset(pudp, addr); + pmd = READ_ONCE(*pmdp); + if (pmd_none(pmd)) + return 0; + + if (pmd_sect(pmd)) + return pfn_valid(pmd_pfn(pmd)); + + ptep = pte_offset_kernel(pmdp, addr); + pte = READ_ONCE(*ptep); + if (pte_none(pte)) + return 0; + + return pfn_valid(pte_pfn(pte)); +} +#ifdef CONFIG_SPARSEMEM_VMEMMAP +#if !ARM64_SWAPPER_USES_SECTION_MAPS +int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, + struct vmem_altmap *altmap) +{ + return vmemmap_populate_basepages(start, end, node); +} +#else /* !ARM64_SWAPPER_USES_SECTION_MAPS */ +int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, + struct vmem_altmap *altmap) +{ + unsigned long addr = start; + unsigned long next; + pgd_t *pgdp; + pud_t *pudp; + pmd_t *pmdp; + + do { + next = pmd_addr_end(addr, end); + + pgdp = vmemmap_pgd_populate(addr, node); + if (!pgdp) + return -ENOMEM; + + pudp = vmemmap_pud_populate(pgdp, addr, node); + if (!pudp) + return -ENOMEM; + + pmdp = pmd_offset(pudp, addr); + if (pmd_none(READ_ONCE(*pmdp))) { + void *p = NULL; + + p = vmemmap_alloc_block_buf(PMD_SIZE, node); + if (!p) + return -ENOMEM; + + pmd_set_huge(pmdp, __pa(p), __pgprot(PROT_SECT_NORMAL)); + } else + vmemmap_verify((pte_t *)pmdp, node, addr, next); + } while (addr = next, addr != end); + + return 0; +} +#endif /* CONFIG_ARM64_64K_PAGES */ +void vmemmap_free(unsigned long start, unsigned long end, + struct vmem_altmap *altmap) +{ +} +#endif /* CONFIG_SPARSEMEM_VMEMMAP */ + +static inline pud_t * fixmap_pud(unsigned long addr) +{ + pgd_t *pgdp = pgd_offset_k(addr); + pgd_t pgd = READ_ONCE(*pgdp); + + BUG_ON(pgd_none(pgd) || pgd_bad(pgd)); + + return pud_offset_kimg(pgdp, addr); +} + +static inline pmd_t * fixmap_pmd(unsigned long addr) +{ + pud_t *pudp = fixmap_pud(addr); + pud_t pud = READ_ONCE(*pudp); + + BUG_ON(pud_none(pud) || pud_bad(pud)); + + return pmd_offset_kimg(pudp, addr); +} + +static inline pte_t * fixmap_pte(unsigned long addr) +{ + return &bm_pte[pte_index(addr)]; +} + +/* + * The p*d_populate functions call virt_to_phys implicitly so they can't be used + * directly on kernel symbols (bm_p*d). This function is called too early to use + * lm_alias so __p*d_populate functions must be used to populate with the + * physical address from __pa_symbol. + */ +void __init early_fixmap_init(void) +{ + pgd_t *pgdp, pgd; + pud_t *pudp; + pmd_t *pmdp; + unsigned long addr = FIXADDR_START; + + pgdp = pgd_offset_k(addr); + pgd = READ_ONCE(*pgdp); + if (CONFIG_PGTABLE_LEVELS > 3 && + !(pgd_none(pgd) || pgd_page_paddr(pgd) == __pa_symbol(bm_pud))) { + /* + * We only end up here if the kernel mapping and the fixmap + * share the top level pgd entry, which should only happen on + * 16k/4 levels configurations. + */ + BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES)); + pudp = pud_offset_kimg(pgdp, addr); + } else { + if (pgd_none(pgd)) + __pgd_populate(pgdp, __pa_symbol(bm_pud), PUD_TYPE_TABLE); + pudp = fixmap_pud(addr); + } + if (pud_none(READ_ONCE(*pudp))) + __pud_populate(pudp, __pa_symbol(bm_pmd), PMD_TYPE_TABLE); + pmdp = fixmap_pmd(addr); + __pmd_populate(pmdp, __pa_symbol(bm_pte), PMD_TYPE_TABLE); + + /* + * The boot-ioremap range spans multiple pmds, for which + * we are not prepared: + */ + BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) + != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); + + if ((pmdp != fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN))) + || pmdp != fixmap_pmd(fix_to_virt(FIX_BTMAP_END))) { + WARN_ON(1); + pr_warn("pmdp %p != %p, %p\n", + pmdp, fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)), + fixmap_pmd(fix_to_virt(FIX_BTMAP_END))); + pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", + fix_to_virt(FIX_BTMAP_BEGIN)); + pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n", + fix_to_virt(FIX_BTMAP_END)); + + pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END); + pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN); + } +} + +/* + * Unusually, this is also called in IRQ context (ghes_iounmap_irq) so if we + * ever need to use IPIs for TLB broadcasting, then we're in trouble here. + */ +void __set_fixmap(enum fixed_addresses idx, + phys_addr_t phys, pgprot_t flags) +{ + unsigned long addr = __fix_to_virt(idx); + pte_t *ptep; + + BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); + + ptep = fixmap_pte(addr); + + if (pgprot_val(flags)) { + set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, flags)); + } else { + pte_clear(&init_mm, addr, ptep); + flush_tlb_kernel_range(addr, addr+PAGE_SIZE); + } +} + +void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot) +{ + const u64 dt_virt_base = __fix_to_virt(FIX_FDT); + int offset; + void *dt_virt; + + /* + * Check whether the physical FDT address is set and meets the minimum + * alignment requirement. Since we are relying on MIN_FDT_ALIGN to be + * at least 8 bytes so that we can always access the magic and size + * fields of the FDT header after mapping the first chunk, double check + * here if that is indeed the case. + */ + BUILD_BUG_ON(MIN_FDT_ALIGN < 8); + if (!dt_phys || dt_phys % MIN_FDT_ALIGN) + return NULL; + + /* + * Make sure that the FDT region can be mapped without the need to + * allocate additional translation table pages, so that it is safe + * to call create_mapping_noalloc() this early. + * + * On 64k pages, the FDT will be mapped using PTEs, so we need to + * be in the same PMD as the rest of the fixmap. + * On 4k pages, we'll use section mappings for the FDT so we only + * have to be in the same PUD. + */ + BUILD_BUG_ON(dt_virt_base % SZ_2M); + + BUILD_BUG_ON(__fix_to_virt(FIX_FDT_END) >> SWAPPER_TABLE_SHIFT != + __fix_to_virt(FIX_BTMAP_BEGIN) >> SWAPPER_TABLE_SHIFT); + + offset = dt_phys % SWAPPER_BLOCK_SIZE; + dt_virt = (void *)dt_virt_base + offset; + + /* map the first chunk so we can read the size from the header */ + create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE), + dt_virt_base, SWAPPER_BLOCK_SIZE, prot); + + if (fdt_magic(dt_virt) != FDT_MAGIC) + return NULL; + + *size = fdt_totalsize(dt_virt); + if (*size > MAX_FDT_SIZE) + return NULL; + + if (offset + *size > SWAPPER_BLOCK_SIZE) + create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE), dt_virt_base, + round_up(offset + *size, SWAPPER_BLOCK_SIZE), prot); + + return dt_virt; +} + +void *__init fixmap_remap_fdt(phys_addr_t dt_phys) +{ + void *dt_virt; + int size; + + dt_virt = __fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO); + if (!dt_virt) + return NULL; + + memblock_reserve(dt_phys, size); + return dt_virt; +} + +int __init arch_ioremap_pud_supported(void) +{ + /* + * Only 4k granule supports level 1 block mappings. + * SW table walks can't handle removal of intermediate entries. + */ + return IS_ENABLED(CONFIG_ARM64_4K_PAGES) && + !IS_ENABLED(CONFIG_ARM64_PTDUMP_DEBUGFS); +} + +int __init arch_ioremap_pmd_supported(void) +{ + /* See arch_ioremap_pud_supported() */ + return !IS_ENABLED(CONFIG_ARM64_PTDUMP_DEBUGFS); +} + +int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot) +{ + pgprot_t sect_prot = __pgprot(PUD_TYPE_SECT | + pgprot_val(mk_sect_prot(prot))); + pud_t new_pud = pfn_pud(__phys_to_pfn(phys), sect_prot); + + /* Only allow permission changes for now */ + if (!pgattr_change_is_safe(READ_ONCE(pud_val(*pudp)), + pud_val(new_pud))) + return 0; + + 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) +{ + pgprot_t sect_prot = __pgprot(PMD_TYPE_SECT | + pgprot_val(mk_sect_prot(prot))); + pmd_t new_pmd = pfn_pmd(__phys_to_pfn(phys), sect_prot); + + /* Only allow permission changes for now */ + if (!pgattr_change_is_safe(READ_ONCE(pmd_val(*pmdp)), + pmd_val(new_pmd))) + return 0; + + 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_present(pmd)) + return 1; + if (!pmd_table(pmd)) { + VM_WARN_ON(!pmd_table(pmd)); + 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_present(pud)) + return 1; + if (!pud_table(pud)) { + VM_WARN_ON(!pud_table(pud)); + 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; +} |