// SPDX-License-Identifier: GPL-2.0-only /* * linux/arch/arm/mm/init.c * * Copyright (C) 1995-2005 Russell King */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "mm.h" #ifdef CONFIG_CPU_CP15_MMU unsigned long __init __clear_cr(unsigned long mask) { cr_alignment = cr_alignment & ~mask; return cr_alignment; } #endif #ifdef CONFIG_BLK_DEV_INITRD static int __init parse_tag_initrd(const struct tag *tag) { pr_warn("ATAG_INITRD is deprecated; " "please update your bootloader.\n"); phys_initrd_start = __virt_to_phys(tag->u.initrd.start); phys_initrd_size = tag->u.initrd.size; return 0; } __tagtable(ATAG_INITRD, parse_tag_initrd); static int __init parse_tag_initrd2(const struct tag *tag) { phys_initrd_start = tag->u.initrd.start; phys_initrd_size = tag->u.initrd.size; return 0; } __tagtable(ATAG_INITRD2, parse_tag_initrd2); #endif static void __init find_limits(unsigned long *min, unsigned long *max_low, unsigned long *max_high) { *max_low = PFN_DOWN(memblock_get_current_limit()); *min = PFN_UP(memblock_start_of_DRAM()); *max_high = PFN_DOWN(memblock_end_of_DRAM()); } #ifdef CONFIG_ZONE_DMA phys_addr_t arm_dma_zone_size __read_mostly; EXPORT_SYMBOL(arm_dma_zone_size); /* * The DMA mask corresponding to the maximum bus address allocatable * using GFP_DMA. The default here places no restriction on DMA * allocations. This must be the smallest DMA mask in the system, * so a successful GFP_DMA allocation will always satisfy this. */ phys_addr_t arm_dma_limit; unsigned long arm_dma_pfn_limit; static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole, unsigned long dma_size) { if (size[0] <= dma_size) return; size[ZONE_NORMAL] = size[0] - dma_size; size[ZONE_DMA] = dma_size; hole[ZONE_NORMAL] = hole[0]; hole[ZONE_DMA] = 0; } #endif void __init setup_dma_zone(const struct machine_desc *mdesc) { #ifdef CONFIG_ZONE_DMA if (mdesc->dma_zone_size) { arm_dma_zone_size = mdesc->dma_zone_size; arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1; } else arm_dma_limit = 0xffffffff; arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT; #endif } static void __init zone_sizes_init(unsigned long min, unsigned long max_low, unsigned long max_high) { unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES]; struct memblock_region *reg; /* * initialise the zones. */ memset(zone_size, 0, sizeof(zone_size)); /* * The memory size has already been determined. If we need * to do anything fancy with the allocation of this memory * to the zones, now is the time to do it. */ zone_size[0] = max_low - min; #ifdef CONFIG_HIGHMEM zone_size[ZONE_HIGHMEM] = max_high - max_low; #endif /* * Calculate the size of the holes. * holes = node_size - sum(bank_sizes) */ memcpy(zhole_size, zone_size, sizeof(zhole_size)); for_each_memblock(memory, reg) { unsigned long start = memblock_region_memory_base_pfn(reg); unsigned long end = memblock_region_memory_end_pfn(reg); if (start < max_low) { unsigned long low_end = min(end, max_low); zhole_size[0] -= low_end - start; } #ifdef CONFIG_HIGHMEM if (end > max_low) { unsigned long high_start = max(start, max_low); zhole_size[ZONE_HIGHMEM] -= end - high_start; } #endif } #ifdef CONFIG_ZONE_DMA /* * Adjust the sizes according to any special requirements for * this machine type. */ if (arm_dma_zone_size) arm_adjust_dma_zone(zone_size, zhole_size, arm_dma_zone_size >> PAGE_SHIFT); #endif free_area_init_node(0, zone_size, min, zhole_size); } #ifdef CONFIG_HAVE_ARCH_PFN_VALID int pfn_valid(unsigned long pfn) { phys_addr_t addr = __pfn_to_phys(pfn); if (__phys_to_pfn(addr) != pfn) return 0; return memblock_is_map_memory(addr); } EXPORT_SYMBOL(pfn_valid); #endif static bool arm_memblock_steal_permitted = true; phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align) { phys_addr_t phys; BUG_ON(!arm_memblock_steal_permitted); phys = memblock_phys_alloc(size, align); if (!phys) panic("Failed to steal %pa bytes at %pS\n", &size, (void *)_RET_IP_); memblock_free(phys, size); memblock_remove(phys, size); return phys; } static void __init arm_initrd_init(void) { #ifdef CONFIG_BLK_DEV_INITRD phys_addr_t start; unsigned long size; initrd_start = initrd_end = 0; if (!phys_initrd_size) return; /* * Round the memory region to page boundaries as per free_initrd_mem() * This allows us to detect whether the pages overlapping the initrd * are in use, but more importantly, reserves the entire set of pages * as we don't want these pages allocated for other purposes. */ start = round_down(phys_initrd_start, PAGE_SIZE); size = phys_initrd_size + (phys_initrd_start - start); size = round_up(size, PAGE_SIZE); if (!memblock_is_region_memory(start, size)) { pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n", (u64)start, size); return; } if (memblock_is_region_reserved(start, size)) { pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n", (u64)start, size); return; } memblock_reserve(start, size); /* Now convert initrd to virtual addresses */ initrd_start = __phys_to_virt(phys_initrd_start); initrd_end = initrd_start + phys_initrd_size; #endif } #ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND void check_cpu_icache_size(int cpuid) { u32 size, ctr; asm("mrc p15, 0, %0, c0, c0, 1" : "=r" (ctr)); size = 1 << ((ctr & 0xf) + 2); if (cpuid != 0 && icache_size != size) pr_info("CPU%u: detected I-Cache line size mismatch, workaround enabled\n", cpuid); if (icache_size > size) icache_size = size; } #endif void __init arm_memblock_init(const struct machine_desc *mdesc) { /* Register the kernel text, kernel data and initrd with memblock. */ memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START); arm_initrd_init(); arm_mm_memblock_reserve(); /* reserve any platform specific memblock areas */ if (mdesc->reserve) mdesc->reserve(); early_init_fdt_reserve_self(); early_init_fdt_scan_reserved_mem(); /* reserve memory for DMA contiguous allocations */ dma_contiguous_reserve(arm_dma_limit); arm_memblock_steal_permitted = false; memblock_dump_all(); } void __init bootmem_init(void) { memblock_allow_resize(); find_limits(&min_low_pfn, &max_low_pfn, &max_pfn); early_memtest((phys_addr_t)min_low_pfn << PAGE_SHIFT, (phys_addr_t)max_low_pfn << PAGE_SHIFT); /* * Sparsemem tries to allocate bootmem in memory_present(), * so must be done after the fixed reservations */ memblocks_present(); /* * sparse_init() needs the bootmem allocator up and running. */ sparse_init(); /* * Now free the memory - free_area_init_node needs * the sparse mem_map arrays initialized by sparse_init() * for memmap_init_zone(), otherwise all PFNs are invalid. */ zone_sizes_init(min_low_pfn, max_low_pfn, max_pfn); } /* * Poison init memory with an undefined instruction (ARM) or a branch to an * undefined instruction (Thumb). */ static inline void poison_init_mem(void *s, size_t count) { u32 *p = (u32 *)s; for (; count != 0; count -= 4) *p++ = 0xe7fddef0; } static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn) { struct page *start_pg, *end_pg; phys_addr_t pg, pgend; /* * Convert start_pfn/end_pfn to a struct page pointer. */ start_pg = pfn_to_page(start_pfn - 1) + 1; end_pg = pfn_to_page(end_pfn - 1) + 1; /* * Convert to physical addresses, and * round start upwards and end downwards. */ pg = PAGE_ALIGN(__pa(start_pg)); pgend = __pa(end_pg) & PAGE_MASK; /* * If there are free pages between these, * free the section of the memmap array. */ if (pg < pgend) memblock_free_early(pg, pgend - pg); } /* * The mem_map array can get very big. Free the unused area of the memory map. */ static void __init free_unused_memmap(void) { unsigned long start, prev_end = 0; struct memblock_region *reg; /* * This relies on each bank being in address order. * The banks are sorted previously in bootmem_init(). */ for_each_memblock(memory, reg) { start = memblock_region_memory_base_pfn(reg); #ifdef CONFIG_SPARSEMEM /* * Take care not to free memmap entries that don't exist * due to SPARSEMEM sections which aren't present. */ start = min(start, ALIGN(prev_end, PAGES_PER_SECTION)); #else /* * Align down here since the VM subsystem insists that the * memmap entries are valid from the bank start aligned to * MAX_ORDER_NR_PAGES. */ start = round_down(start, MAX_ORDER_NR_PAGES); #endif /* * If we had a previous bank, and there is a space * between the current bank and the previous, free it. */ if (prev_end && prev_end < start) free_memmap(prev_end, start); /* * Align up here since the VM subsystem insists that the * memmap entries are valid from the bank end aligned to * MAX_ORDER_NR_PAGES. */ prev_end = ALIGN(memblock_region_memory_end_pfn(reg), MAX_ORDER_NR_PAGES); } #ifdef CONFIG_SPARSEMEM if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION)) free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION)); #endif } #ifdef CONFIG_HIGHMEM static inline void free_area_high(unsigned long pfn, unsigned long end) { for (; pfn < end; pfn++) free_highmem_page(pfn_to_page(pfn)); } #endif static void __init free_highpages(void) { #ifdef CONFIG_HIGHMEM unsigned long max_low = max_low_pfn; struct memblock_region *mem, *res; /* set highmem page free */ for_each_memblock(memory, mem) { unsigned long start = memblock_region_memory_base_pfn(mem); unsigned long end = memblock_region_memory_end_pfn(mem); /* Ignore complete lowmem entries */ if (end <= max_low) continue; if (memblock_is_nomap(mem)) continue; /* Truncate partial highmem entries */ if (start < max_low) start = max_low; /* Find and exclude any reserved regions */ for_each_memblock(reserved, res) { unsigned long res_start, res_end; res_start = memblock_region_reserved_base_pfn(res); res_end = memblock_region_reserved_end_pfn(res); if (res_end < start) continue; if (res_start < start) res_start = start; if (res_start > end) res_start = end; if (res_end > end) res_end = end; if (res_start != start) free_area_high(start, res_start); start = res_end; if (start == end) break; } /* And now free anything which remains */ if (start < end) free_area_high(start, end); } #endif } /* * mem_init() marks the free areas in the mem_map and tells us how much * memory is free. This is done after various parts of the system have * claimed their memory after the kernel image. */ void __init mem_init(void) { #ifdef CONFIG_ARM_LPAE swiotlb_init(1); #endif set_max_mapnr(pfn_to_page(max_pfn) - mem_map); /* this will put all unused low memory onto the freelists */ free_unused_memmap(); memblock_free_all(); #ifdef CONFIG_SA1111 /* now that our DMA memory is actually so designated, we can free it */ free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL); #endif free_highpages(); mem_init_print_info(NULL); /* * Check boundaries twice: Some fundamental inconsistencies can * be detected at build time already. */ #ifdef CONFIG_MMU BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR); BUG_ON(TASK_SIZE > MODULES_VADDR); #endif #ifdef CONFIG_HIGHMEM BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET); BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET); #endif } #ifdef CONFIG_STRICT_KERNEL_RWX struct section_perm { const char *name; unsigned long start; unsigned long end; pmdval_t mask; pmdval_t prot; pmdval_t clear; }; /* First section-aligned location at or after __start_rodata. */ extern char __start_rodata_section_aligned[]; static struct section_perm nx_perms[] = { /* Make pages tables, etc before _stext RW (set NX). */ { .name = "pre-text NX", .start = PAGE_OFFSET, .end = (unsigned long)_stext, .mask = ~PMD_SECT_XN, .prot = PMD_SECT_XN, }, /* Make init RW (set NX). */ { .name = "init NX", .start = (unsigned long)__init_begin, .end = (unsigned long)_sdata, .mask = ~PMD_SECT_XN, .prot = PMD_SECT_XN, }, /* Make rodata NX (set RO in ro_perms below). */ { .name = "rodata NX", .start = (unsigned long)__start_rodata_section_aligned, .end = (unsigned long)__init_begin, .mask = ~PMD_SECT_XN, .prot = PMD_SECT_XN, }, }; static struct section_perm ro_perms[] = { /* Make kernel code and rodata RX (set RO). */ { .name = "text/rodata RO", .start = (unsigned long)_stext, .end = (unsigned long)__init_begin, #ifdef CONFIG_ARM_LPAE .mask = ~(L_PMD_SECT_RDONLY | PMD_SECT_AP2), .prot = L_PMD_SECT_RDONLY | PMD_SECT_AP2, #else .mask = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE), .prot = PMD_SECT_APX | PMD_SECT_AP_WRITE, .clear = PMD_SECT_AP_WRITE, #endif }, }; /* * Updates section permissions only for the current mm (sections are * copied into each mm). During startup, this is the init_mm. Is only * safe to be called with preemption disabled, as under stop_machine(). */ static inline void section_update(unsigned long addr, pmdval_t mask, pmdval_t prot, struct mm_struct *mm) { pmd_t *pmd; pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr); #ifdef CONFIG_ARM_LPAE pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot); #else if (addr & SECTION_SIZE) pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot); else pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot); #endif flush_pmd_entry(pmd); local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE); } /* Make sure extended page tables are in use. */ static inline bool arch_has_strict_perms(void) { if (cpu_architecture() < CPU_ARCH_ARMv6) return false; return !!(get_cr() & CR_XP); } void set_section_perms(struct section_perm *perms, int n, bool set, struct mm_struct *mm) { size_t i; unsigned long addr; if (!arch_has_strict_perms()) return; for (i = 0; i < n; i++) { if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) || !IS_ALIGNED(perms[i].end, SECTION_SIZE)) { pr_err("BUG: %s section %lx-%lx not aligned to %lx\n", perms[i].name, perms[i].start, perms[i].end, SECTION_SIZE); continue; } for (addr = perms[i].start; addr < perms[i].end; addr += SECTION_SIZE) section_update(addr, perms[i].mask, set ? perms[i].prot : perms[i].clear, mm); } } /** * update_sections_early intended to be called only through stop_machine * framework and executed by only one CPU while all other CPUs will spin and * wait, so no locking is required in this function. */ static void update_sections_early(struct section_perm perms[], int n) { struct task_struct *t, *s; for_each_process(t) { if (t->flags & PF_KTHREAD) continue; for_each_thread(t, s) if (s->mm) set_section_perms(perms, n, true, s->mm); } set_section_perms(perms, n, true, current->active_mm); set_section_perms(perms, n, true, &init_mm); } static int __fix_kernmem_perms(void *unused) { update_sections_early(nx_perms, ARRAY_SIZE(nx_perms)); return 0; } static void fix_kernmem_perms(void) { stop_machine(__fix_kernmem_perms, NULL, NULL); } static int __mark_rodata_ro(void *unused) { update_sections_early(ro_perms, ARRAY_SIZE(ro_perms)); return 0; } static int kernel_set_to_readonly __read_mostly; void mark_rodata_ro(void) { kernel_set_to_readonly = 1; stop_machine(__mark_rodata_ro, NULL, NULL); debug_checkwx(); } void set_kernel_text_rw(void) { if (!kernel_set_to_readonly) return; set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false, current->active_mm); } void set_kernel_text_ro(void) { if (!kernel_set_to_readonly) return; set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true, current->active_mm); } #else static inline void fix_kernmem_perms(void) { } #endif /* CONFIG_STRICT_KERNEL_RWX */ void free_initmem(void) { fix_kernmem_perms(); poison_init_mem(__init_begin, __init_end - __init_begin); if (!machine_is_integrator() && !machine_is_cintegrator()) free_initmem_default(-1); } #ifdef CONFIG_BLK_DEV_INITRD void free_initrd_mem(unsigned long start, unsigned long end) { if (start == initrd_start) start = round_down(start, PAGE_SIZE); if (end == initrd_end) end = round_up(end, PAGE_SIZE); poison_init_mem((void *)start, PAGE_ALIGN(end) - start); free_reserved_area((void *)start, (void *)end, -1, "initrd"); } #endif