diff options
Diffstat (limited to 'kernel/arch/arm64/mm/mmu.c')
| -rw-r--r-- | kernel/arch/arm64/mm/mmu.c | 150 |
1 files changed, 102 insertions, 48 deletions
diff --git a/kernel/arch/arm64/mm/mmu.c b/kernel/arch/arm64/mm/mmu.c index 5b8b66442..116ad654d 100644 --- a/kernel/arch/arm64/mm/mmu.c +++ b/kernel/arch/arm64/mm/mmu.c @@ -21,6 +21,7 @@ #include <linux/kernel.h> #include <linux/errno.h> #include <linux/init.h> +#include <linux/libfdt.h> #include <linux/mman.h> #include <linux/nodemask.h> #include <linux/memblock.h> @@ -31,6 +32,7 @@ #include <asm/cputype.h> #include <asm/fixmap.h> +#include <asm/kernel-pgtable.h> #include <asm/sections.h> #include <asm/setup.h> #include <asm/sizes.h> @@ -62,8 +64,12 @@ EXPORT_SYMBOL(phys_mem_access_prot); static void __init *early_alloc(unsigned long sz) { - void *ptr = __va(memblock_alloc(sz, sz)); - BUG_ON(!ptr); + phys_addr_t phys; + void *ptr; + + phys = memblock_alloc(sz, sz); + BUG_ON(!phys); + ptr = __va(phys); memset(ptr, 0, sz); return ptr; } @@ -109,14 +115,14 @@ static void alloc_init_pte(pmd_t *pmd, unsigned long addr, } while (pte++, addr += PAGE_SIZE, addr != end); } -void split_pud(pud_t *old_pud, pmd_t *pmd) +static void split_pud(pud_t *old_pud, pmd_t *pmd) { unsigned long addr = pud_pfn(*old_pud) << PAGE_SHIFT; pgprot_t prot = __pgprot(pud_val(*old_pud) ^ addr); int i = 0; do { - set_pmd(pmd, __pmd(addr | prot)); + set_pmd(pmd, __pmd(addr | pgprot_val(prot))); addr += PMD_SIZE; } while (pmd++, i++, i < PTRS_PER_PMD); } @@ -266,7 +272,7 @@ static void *late_alloc(unsigned long size) return ptr; } -static void __ref create_mapping(phys_addr_t phys, unsigned long virt, +static void __init create_mapping(phys_addr_t phys, unsigned long virt, phys_addr_t size, pgprot_t prot) { if (virt < VMALLOC_START) { @@ -307,8 +313,8 @@ static void __init __map_memblock(phys_addr_t start, phys_addr_t end) * for now. This will get more fine grained later once all memory * is mapped */ - unsigned long kernel_x_start = round_down(__pa(_stext), SECTION_SIZE); - unsigned long kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE); + unsigned long kernel_x_start = round_down(__pa(_stext), SWAPPER_BLOCK_SIZE); + unsigned long kernel_x_end = round_up(__pa(__init_end), SWAPPER_BLOCK_SIZE); if (end < kernel_x_start) { create_mapping(start, __phys_to_virt(start), @@ -352,14 +358,11 @@ static void __init map_mem(void) * memory addressable from the initial direct kernel mapping. * * The initial direct kernel mapping, located at swapper_pg_dir, gives - * us PUD_SIZE (4K pages) or PMD_SIZE (64K pages) memory starting from - * PHYS_OFFSET (which must be aligned to 2MB as per - * Documentation/arm64/booting.txt). + * us PUD_SIZE (with SECTION maps) or PMD_SIZE (without SECTION maps, + * memory starting from PHYS_OFFSET (which must be aligned to 2MB as + * per Documentation/arm64/booting.txt). */ - if (IS_ENABLED(CONFIG_ARM64_64K_PAGES)) - limit = PHYS_OFFSET + PMD_SIZE; - else - limit = PHYS_OFFSET + PUD_SIZE; + limit = PHYS_OFFSET + SWAPPER_INIT_MAP_SIZE; memblock_set_current_limit(limit); /* map all the memory banks */ @@ -370,21 +373,24 @@ static void __init map_mem(void) if (start >= end) break; -#ifndef CONFIG_ARM64_64K_PAGES - /* - * For the first memory bank align the start address and - * current memblock limit to prevent create_mapping() from - * allocating pte page tables from unmapped memory. - * When 64K pages are enabled, the pte page table for the - * first PGDIR_SIZE is already present in swapper_pg_dir. - */ - if (start < limit) - start = ALIGN(start, PMD_SIZE); - if (end < limit) { - limit = end & PMD_MASK; - memblock_set_current_limit(limit); + if (ARM64_SWAPPER_USES_SECTION_MAPS) { + /* + * For the first memory bank align the start address and + * current memblock limit to prevent create_mapping() from + * allocating pte page tables from unmapped memory. With + * the section maps, if the first block doesn't end on section + * size boundary, create_mapping() will try to allocate a pte + * page, which may be returned from an unmapped area. + * When section maps are not used, the pte page table for the + * current limit is already present in swapper_pg_dir. + */ + if (start < limit) + start = ALIGN(start, SECTION_SIZE); + if (end < limit) { + limit = end & SECTION_MASK; + memblock_set_current_limit(limit); + } } -#endif __map_memblock(start, end); } @@ -392,22 +398,22 @@ static void __init map_mem(void) memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE); } -void __init fixup_executable(void) +static void __init fixup_executable(void) { #ifdef CONFIG_DEBUG_RODATA /* now that we are actually fully mapped, make the start/end more fine grained */ - if (!IS_ALIGNED((unsigned long)_stext, SECTION_SIZE)) { + if (!IS_ALIGNED((unsigned long)_stext, SWAPPER_BLOCK_SIZE)) { unsigned long aligned_start = round_down(__pa(_stext), - SECTION_SIZE); + SWAPPER_BLOCK_SIZE); create_mapping(aligned_start, __phys_to_virt(aligned_start), __pa(_stext) - aligned_start, PAGE_KERNEL); } - if (!IS_ALIGNED((unsigned long)__init_end, SECTION_SIZE)) { + if (!IS_ALIGNED((unsigned long)__init_end, SWAPPER_BLOCK_SIZE)) { unsigned long aligned_end = round_up(__pa(__init_end), - SECTION_SIZE); + SWAPPER_BLOCK_SIZE); create_mapping(__pa(__init_end), (unsigned long)__init_end, aligned_end - __pa(__init_end), PAGE_KERNEL); @@ -420,7 +426,7 @@ void mark_rodata_ro(void) { create_mapping_late(__pa(_stext), (unsigned long)_stext, (unsigned long)_etext - (unsigned long)_stext, - PAGE_KERNEL_EXEC | PTE_RDONLY); + PAGE_KERNEL_ROX); } #endif @@ -450,27 +456,19 @@ void __init paging_init(void) empty_zero_page = virt_to_page(zero_page); + /* Ensure the zero page is visible to the page table walker */ + dsb(ishst); + /* * TTBR0 is only used for the identity mapping at this stage. Make it * point to zero page to avoid speculatively fetching new entries. */ cpu_set_reserved_ttbr0(); - flush_tlb_all(); + local_flush_tlb_all(); cpu_set_default_tcr_t0sz(); } /* - * Enable the identity mapping to allow the MMU disabling. - */ -void setup_mm_for_reboot(void) -{ - cpu_set_reserved_ttbr0(); - flush_tlb_all(); - cpu_set_idmap_tcr_t0sz(); - cpu_switch_mm(idmap_pg_dir, &init_mm); -} - -/* * Check whether a kernel address is valid (derived from arch/x86/). */ int kern_addr_valid(unsigned long addr) @@ -508,12 +506,12 @@ int kern_addr_valid(unsigned long addr) return pfn_valid(pte_pfn(*pte)); } #ifdef CONFIG_SPARSEMEM_VMEMMAP -#ifdef CONFIG_ARM64_64K_PAGES +#if !ARM64_SWAPPER_USES_SECTION_MAPS int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) { return vmemmap_populate_basepages(start, end, node); } -#else /* !CONFIG_ARM64_64K_PAGES */ +#else /* !ARM64_SWAPPER_USES_SECTION_MAPS */ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) { unsigned long addr = start; @@ -643,3 +641,59 @@ void __set_fixmap(enum fixed_addresses idx, flush_tlb_kernel_range(addr, addr+PAGE_SIZE); } } + +void *__init fixmap_remap_fdt(phys_addr_t dt_phys) +{ + const u64 dt_virt_base = __fix_to_virt(FIX_FDT); + pgprot_t prot = PAGE_KERNEL_RO; + int size, 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 size field 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() 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(round_down(dt_phys, SWAPPER_BLOCK_SIZE), dt_virt_base, + SWAPPER_BLOCK_SIZE, prot); + + if (fdt_check_header(dt_virt) != 0) + return NULL; + + size = fdt_totalsize(dt_virt); + if (size > MAX_FDT_SIZE) + return NULL; + + if (offset + size > SWAPPER_BLOCK_SIZE) + create_mapping(round_down(dt_phys, SWAPPER_BLOCK_SIZE), dt_virt_base, + round_up(offset + size, SWAPPER_BLOCK_SIZE), prot); + + memblock_reserve(dt_phys, size); + + return dt_virt; +} |