From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752410Ab2IGQ2l (ORCPT ); Fri, 7 Sep 2012 12:28:41 -0400 Received: from service87.mimecast.com ([91.220.42.44]:34239 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751371Ab2IGQ1w (ORCPT ); Fri, 7 Sep 2012 12:27:52 -0400 From: Catalin Marinas To: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Arnd Bergmann Subject: [PATCH v3 05/31] arm64: MMU initialisation Date: Fri, 7 Sep 2012 17:26:40 +0100 Message-Id: <1347035226-18649-6-git-send-email-catalin.marinas@arm.com> X-Mailer: git-send-email 1.7.9.111.gf3fb0 In-Reply-To: <1347035226-18649-1-git-send-email-catalin.marinas@arm.com> References: <1347035226-18649-1-git-send-email-catalin.marinas@arm.com> X-OriginalArrivalTime: 07 Sep 2012 16:27:49.0410 (UTC) FILETIME=[B8934020:01CD8D15] X-MC-Unique: 112090717275016201 Content-Type: text/plain; charset=WINDOWS-1252 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id q87GSnac008348 This patch contains the initialisation of the memory blocks, MMU attributes and the memory map. Only five memory types are defined: Device nGnRnE (equivalent to Strongly Ordered), Device nGnRE (classic Device memory), Device GRE, Normal Non-cacheable and Normal Cacheable. Cache policies are supported via the memory attributes register (MAIR_EL1) and only affect the Normal Cacheable mappings. This patch also adds the SPARSEMEM_VMEMMAP initialisation. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Acked-by: Tony Lindgren --- arch/arm64/include/asm/memblock.h | 21 ++ arch/arm64/mm/init.c | 416 +++++++++++++++++++++++++++++++++++++ arch/arm64/mm/mmu.c | 395 +++++++++++++++++++++++++++++++++++ 3 files changed, 832 insertions(+), 0 deletions(-) create mode 100644 arch/arm64/include/asm/memblock.h create mode 100644 arch/arm64/mm/init.c create mode 100644 arch/arm64/mm/mmu.c diff --git a/arch/arm64/include/asm/memblock.h b/arch/arm64/include/asm/memblock.h new file mode 100644 index 0000000..6afeed2 --- /dev/null +++ b/arch/arm64/include/asm/memblock.h @@ -0,0 +1,21 @@ +/* + * 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 . + */ +#ifndef __ASM_MEMBLOCK_H +#define __ASM_MEMBLOCK_H + +extern void arm64_memblock_init(void); + +#endif diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c new file mode 100644 index 0000000..31428ca --- /dev/null +++ b/arch/arm64/mm/init.c @@ -0,0 +1,416 @@ +/* + * Based on arch/arm/mm/init.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 . + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#include "mm.h" + +static unsigned long phys_initrd_start __initdata = 0; +static unsigned long phys_initrd_size __initdata = 0; + +phys_addr_t memstart_addr __read_mostly = 0; + +void __init early_init_dt_setup_initrd_arch(unsigned long start, + unsigned long end) +{ + phys_initrd_start = start; + phys_initrd_size = end - start; +} + +static int __init early_initrd(char *p) +{ + unsigned long start, size; + char *endp; + + start = memparse(p, &endp); + if (*endp == ',') { + size = memparse(endp + 1, NULL); + + phys_initrd_start = start; + phys_initrd_size = size; + } + return 0; +} +early_param("initrd", early_initrd); + +#define MAX_DMA32_PFN ((4UL * 1024 * 1024 * 1024) >> PAGE_SHIFT) + +static void __init zone_sizes_init(unsigned long min, unsigned long max) +{ + unsigned long zone_size[MAX_NR_ZONES]; + unsigned long max_dma32 = min; + + memset(zone_size, 0, sizeof(zone_size)); + + zone_size[0] = max - min; +#ifdef CONFIG_ZONE_DMA32 + /* 4GB maximum for 32-bit only capable devices */ + max_dma32 = min(max, MAX_DMA32_PFN); + zone_size[ZONE_DMA32] = max_dma32 - min; +#endif + zone_size[ZONE_NORMAL] = max - max_dma32; + + free_area_init(zone_size); +} + +#ifdef CONFIG_HAVE_ARCH_PFN_VALID +int pfn_valid(unsigned long pfn) +{ + return memblock_is_memory(pfn << PAGE_SHIFT); +} +EXPORT_SYMBOL(pfn_valid); +#endif + +#ifndef CONFIG_SPARSEMEM +static void arm64_memory_present(void) +{ +} +#else +static void arm64_memory_present(void) +{ + struct memblock_region *reg; + + for_each_memblock(memory, reg) + memory_present(0, memblock_region_memory_base_pfn(reg), + memblock_region_memory_end_pfn(reg)); +} +#endif + +void __init arm64_memblock_init(void) +{ + u64 *reserve_map, base, size; + + /* Register the kernel text, kernel data and initrd with memblock */ + memblock_reserve(__pa(_text), _end - _text); +#ifdef CONFIG_BLK_DEV_INITRD + if (phys_initrd_size) { + memblock_reserve(phys_initrd_start, phys_initrd_size); + + /* Now convert initrd to virtual addresses */ + initrd_start = __phys_to_virt(phys_initrd_start); + initrd_end = initrd_start + phys_initrd_size; + } +#endif + + /* + * Reserve the page tables. These are already in use, + * and can only be in node 0. + */ + memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE); + memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE); + + /* Reserve the dtb region */ + memblock_reserve(virt_to_phys(initial_boot_params), + be32_to_cpu(initial_boot_params->totalsize)); + + /* + * Process the reserve map. This will probably overlap the initrd + * and dtb locations which are already reserved, but overlapping + * doesn't hurt anything + */ + reserve_map = ((void*)initial_boot_params) + + be32_to_cpu(initial_boot_params->off_mem_rsvmap); + while (1) { + base = be64_to_cpup(reserve_map++); + size = be64_to_cpup(reserve_map++); + if (!size) + break; + memblock_reserve(base, size); + } + + memblock_allow_resize(); + memblock_dump_all(); +} + +void __init bootmem_init(void) +{ + unsigned long min, max; + + min = PFN_UP(memblock_start_of_DRAM()); + max = PFN_DOWN(memblock_end_of_DRAM()); + + /* + * Sparsemem tries to allocate bootmem in memory_present(), so must be + * done after the fixed reservations. + */ + arm64_memory_present(); + + sparse_init(); + zone_sizes_init(min, max); + + high_memory = __va((max << PAGE_SHIFT) - 1) + 1; + max_pfn = max_low_pfn = max; +} + +static inline int free_area(unsigned long pfn, unsigned long end, char *s) +{ + unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10); + + for (; pfn < end; pfn++) { + struct page *page = pfn_to_page(pfn); + ClearPageReserved(page); + init_page_count(page); + __free_page(page); + pages++; + } + + if (size && s) + pr_info("Freeing %s memory: %dK\n", s, size); + + return pages; +} + +/* + * Poison init memory with an undefined instruction (0x0). + */ +static inline void poison_init_mem(void *s, size_t count) +{ + memset(s, 0, count); +} + +#ifndef CONFIG_SPARSEMEM_VMEMMAP +static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn) +{ + struct page *start_pg, *end_pg; + unsigned long 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 = (unsigned long)PAGE_ALIGN(__pa(start_pg)); + pgend = (unsigned long)__pa(end_pg) & PAGE_MASK; + + /* + * If there are free pages between these, free the section of the + * memmap array. + */ + if (pg < pgend) + free_bootmem(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; + + for_each_memblock(memory, reg) { + start = __phys_to_pfn(reg->base); + +#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)); +#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(start + __phys_to_pfn(reg->size), + 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 +} +#endif /* !CONFIG_SPARSEMEM_VMEMMAP */ + +/* + * 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) +{ + unsigned long reserved_pages, free_pages; + struct memblock_region *reg; + +#if CONFIG_SWIOTLB + extern void __init arm64_swiotlb_init(size_t max_size); + arm64_swiotlb_init(max_pfn << (PAGE_SHIFT - 1)); +#endif + + max_mapnr = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map; + +#ifndef CONFIG_SPARSEMEM_VMEMMAP + /* this will put all unused low memory onto the freelists */ + free_unused_memmap(); +#endif + + totalram_pages += free_all_bootmem(); + + reserved_pages = free_pages = 0; + + for_each_memblock(memory, reg) { + unsigned int pfn1, pfn2; + struct page *page, *end; + + pfn1 = __phys_to_pfn(reg->base); + pfn2 = pfn1 + __phys_to_pfn(reg->size); + + page = pfn_to_page(pfn1); + end = pfn_to_page(pfn2 - 1) + 1; + + do { + if (PageReserved(page)) + reserved_pages++; + else if (!page_count(page)) + free_pages++; + page++; + } while (page < end); + } + + /* + * Since our memory may not be contiguous, calculate the real number + * of pages we have in this system. + */ + pr_info("Memory:"); + num_physpages = 0; + for_each_memblock(memory, reg) { + unsigned long pages = memblock_region_memory_end_pfn(reg) - + memblock_region_memory_base_pfn(reg); + num_physpages += pages; + printk(" %ldMB", pages >> (20 - PAGE_SHIFT)); + } + printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT)); + + pr_notice("Memory: %luk/%luk available, %luk reserved\n", + nr_free_pages() << (PAGE_SHIFT-10), + free_pages << (PAGE_SHIFT-10), + reserved_pages << (PAGE_SHIFT-10)); + +#define MLK(b, t) b, t, ((t) - (b)) >> 10 +#define MLM(b, t) b, t, ((t) - (b)) >> 20 +#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K) + + pr_notice("Virtual kernel memory layout:\n" + " vmalloc : 0x%16lx - 0x%16lx (%6ld MB)\n" +#ifdef CONFIG_SPARSEMEM_VMEMMAP + " vmemmap : 0x%16lx - 0x%16lx (%6ld MB)\n" +#endif + " modules : 0x%16lx - 0x%16lx (%6ld MB)\n" + " memory : 0x%16lx - 0x%16lx (%6ld MB)\n" + " .init : 0x%p" " - 0x%p" " (%6ld kB)\n" + " .text : 0x%p" " - 0x%p" " (%6ld kB)\n" + " .data : 0x%p" " - 0x%p" " (%6ld kB)\n", + MLM(VMALLOC_START, VMALLOC_END), +#ifdef CONFIG_SPARSEMEM_VMEMMAP + MLM((unsigned long)virt_to_page(PAGE_OFFSET), + (unsigned long)virt_to_page(high_memory)), +#endif + MLM(MODULES_VADDR, MODULES_END), + MLM(PAGE_OFFSET, (unsigned long)high_memory), + + MLK_ROUNDUP(__init_begin, __init_end), + MLK_ROUNDUP(_text, _etext), + MLK_ROUNDUP(_sdata, _edata)); + +#undef MLK +#undef MLM +#undef MLK_ROUNDUP + + /* + * Check boundaries twice: Some fundamental inconsistencies can be + * detected at build time already. + */ +#ifdef CONFIG_COMPAT + BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64); +#endif + BUILD_BUG_ON(TASK_SIZE_64 > MODULES_VADDR); + BUG_ON(TASK_SIZE_64 > MODULES_VADDR); + + if (PAGE_SIZE >= 16384 && num_physpages <= 128) { + extern int sysctl_overcommit_memory; + /* + * On a machine this small we won't get anywhere without + * overcommit, so turn it on by default. + */ + sysctl_overcommit_memory = OVERCOMMIT_ALWAYS; + } +} + +void free_initmem(void) +{ + poison_init_mem(__init_begin, __init_end - __init_begin); + totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)), + __phys_to_pfn(__pa(__init_end)), + "init"); +} + +#ifdef CONFIG_BLK_DEV_INITRD + +static int keep_initrd; + +void free_initrd_mem(unsigned long start, unsigned long end) +{ + if (!keep_initrd) { + poison_init_mem((void *)start, PAGE_ALIGN(end) - start); + totalram_pages += free_area(__phys_to_pfn(__pa(start)), + __phys_to_pfn(__pa(end)), + "initrd"); + } +} + +static int __init keepinitrd_setup(char *__unused) +{ + keep_initrd = 1; + return 1; +} + +__setup("keepinitrd", keepinitrd_setup); +#endif diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c new file mode 100644 index 0000000..d2dd438 --- /dev/null +++ b/arch/arm64/mm/mmu.c @@ -0,0 +1,395 @@ +/* + * 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 . + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#include "mm.h" + +/* + * Empty_zero_page is a special page that is used for zero-initialized data + * and COW. + */ +struct page *empty_zero_page; +EXPORT_SYMBOL(empty_zero_page); + +pgprot_t pgprot_default; +EXPORT_SYMBOL(pgprot_default); + +static pmdval_t prot_sect_kernel; + +struct cachepolicy { + const char policy[16]; + u64 mair; + u64 tcr; +}; + +static struct cachepolicy cache_policies[] __initdata = { + { + .policy = "uncached", + .mair = 0x44, /* inner, outer non-cacheable */ + .tcr = TCR_IRGN_NC | TCR_ORGN_NC, + }, { + .policy = "writethrough", + .mair = 0xaa, /* inner, outer write-through, read-allocate */ + .tcr = TCR_IRGN_WT | TCR_ORGN_WT, + }, { + .policy = "writeback", + .mair = 0xee, /* inner, outer write-back, read-allocate */ + .tcr = TCR_IRGN_WBnWA | TCR_ORGN_WBnWA, + } +}; + +/* + * These are useful for identifying cache coherency problems by allowing the + * cache or the cache and writebuffer to be turned off. It changes the Normal + * memory caching attributes in the MAIR_EL1 register. + */ +static int __init early_cachepolicy(char *p) +{ + int i; + u64 tmp; + + for (i = 0; i < ARRAY_SIZE(cache_policies); i++) { + int len = strlen(cache_policies[i].policy); + + if (memcmp(p, cache_policies[i].policy, len) == 0) + break; + } + if (i == ARRAY_SIZE(cache_policies)) { + pr_err("ERROR: unknown or unsupported cache policy: %s\n", p); + return 0; + } + + flush_cache_all(); + + /* + * Modify MT_NORMAL attributes in MAIR_EL1. + */ + asm volatile( + " mrs %0, mair_el1\n" + " bfi %0, %1, #%2, #8\n" + " msr mair_el1, %0\n" + " isb\n" + : "=&r" (tmp) + : "r" (cache_policies[i].mair), "i" (MT_NORMAL * 8)); + + /* + * Modify TCR PTW cacheability attributes. + */ + asm volatile( + " mrs %0, tcr_el1\n" + " bic %0, %0, %2\n" + " orr %0, %0, %1\n" + " msr tcr_el1, %0\n" + " isb\n" + : "=&r" (tmp) + : "r" (cache_policies[i].tcr), "r" (TCR_IRGN_MASK | TCR_ORGN_MASK)); + + flush_cache_all(); + + return 0; +} +early_param("cachepolicy", early_cachepolicy); + +/* + * Adjust the PMD section entries according to the CPU in use. + */ +static void __init init_mem_pgprot(void) +{ + pteval_t default_pgprot; + int i; + + default_pgprot = PTE_ATTRINDX(MT_NORMAL); + prot_sect_kernel = PMD_TYPE_SECT | PMD_SECT_AF | PMD_ATTRINDX(MT_NORMAL); + +#ifdef CONFIG_SMP + /* + * Mark memory with the "shared" attribute for SMP systems + */ + default_pgprot |= PTE_SHARED; + prot_sect_kernel |= PMD_SECT_S; +#endif + + for (i = 0; i < 16; i++) { + unsigned long v = pgprot_val(protection_map[i]); + protection_map[i] = __pgprot(v | default_pgprot); + } + + pgprot_default = __pgprot(PTE_TYPE_PAGE | PTE_AF | default_pgprot); +} + +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 void __init *early_alloc(unsigned long sz) +{ + void *ptr = __va(memblock_alloc(sz, sz)); + memset(ptr, 0, sz); + return ptr; +} + +static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, + unsigned long end, unsigned long pfn) +{ + pte_t *pte; + + if (pmd_none(*pmd)) { + pte = early_alloc(PTRS_PER_PTE * sizeof(pte_t)); + __pmd_populate(pmd, __pa(pte), PMD_TYPE_TABLE); + } + BUG_ON(pmd_bad(*pmd)); + + pte = pte_offset_kernel(pmd, addr); + do { + set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); + pfn++; + } while (pte++, addr += PAGE_SIZE, addr != end); +} + +static void __init alloc_init_pmd(pud_t *pud, unsigned long addr, + unsigned long end, phys_addr_t phys) +{ + pmd_t *pmd; + unsigned long next; + + /* + * Check for initial section mappings in the pgd/pud and remove them. + */ + if (pud_none(*pud) || pud_bad(*pud)) { + pmd = early_alloc(PTRS_PER_PMD * sizeof(pmd_t)); + pud_populate(&init_mm, pud, pmd); + } + + pmd = pmd_offset(pud, addr); + do { + next = pmd_addr_end(addr, end); + /* try section mapping first */ + if (((addr | next | phys) & ~SECTION_MASK) == 0) + set_pmd(pmd, __pmd(phys | prot_sect_kernel)); + else + alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys)); + phys += next - addr; + } while (pmd++, addr = next, addr != end); +} + +static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr, + unsigned long end, unsigned long phys) +{ + pud_t *pud = pud_offset(pgd, addr); + unsigned long next; + + do { + next = pud_addr_end(addr, end); + alloc_init_pmd(pud, addr, next, phys); + phys += next - addr; + } while (pud++, addr = next, addr != end); +} + +/* + * Create the page directory entries and any necessary page tables for the + * mapping specified by 'md'. + */ +static void __init create_mapping(phys_addr_t phys, unsigned long virt, + phys_addr_t size) +{ + unsigned long addr, length, end, next; + pgd_t *pgd; + + if (virt < VMALLOC_START) { + pr_warning("BUG: not creating mapping for 0x%016llx at 0x%016lx - outside kernel range\n", + phys, virt); + return; + } + + addr = virt & PAGE_MASK; + length = PAGE_ALIGN(size + (virt & ~PAGE_MASK)); + + pgd = pgd_offset_k(addr); + end = addr + length; + do { + next = pgd_addr_end(addr, end); + alloc_init_pud(pgd, addr, next, phys); + phys += next - addr; + } while (pgd++, addr = next, addr != end); +} + +static void __init map_mem(void) +{ + struct memblock_region *reg; + + /* 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; + + create_mapping(start, __phys_to_virt(start), end - start); + } +} + +/* + * paging_init() sets up the page tables, initialises the zone memory + * maps and sets up the zero page. + */ +void __init paging_init(void) +{ + void *zero_page; + + /* + * Maximum PGDIR_SIZE addressable via the initial direct kernel + * mapping in swapper_pg_dir. + */ + memblock_set_current_limit((PHYS_OFFSET & PGDIR_MASK) + PGDIR_SIZE); + + init_mem_pgprot(); + map_mem(); + + /* + * Finally flush the caches and tlb to ensure that we're in a + * consistent state. + */ + flush_cache_all(); + flush_tlb_all(); + + /* allocate the zero page. */ + zero_page = early_alloc(PAGE_SIZE); + + bootmem_init(); + + empty_zero_page = virt_to_page(zero_page); + __flush_dcache_page(NULL, empty_zero_page); + + /* + * 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(); +} + +/* + * Enable the identity mapping to allow the MMU disabling. + */ +void setup_mm_for_reboot(void) +{ + cpu_switch_mm(idmap_pg_dir, &init_mm); + flush_tlb_all(); +} + +/* + * Check whether a kernel address is valid (derived from arch/x86/). + */ +int kern_addr_valid(unsigned long addr) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + if ((((long)addr) >> VA_BITS) != -1UL) + return 0; + + pgd = pgd_offset_k(addr); + if (pgd_none(*pgd)) + return 0; + + pud = pud_offset(pgd, addr); + if (pud_none(*pud)) + return 0; + + pmd = pmd_offset(pud, addr); + if (pmd_none(*pmd)) + return 0; + + pte = pte_offset_kernel(pmd, addr); + if (pte_none(*pte)) + return 0; + + return pfn_valid(pte_pfn(*pte)); +} +#ifdef CONFIG_SPARSEMEM_VMEMMAP +#ifdef CONFIG_ARM64_64K_PAGES +int __meminit vmemmap_populate(struct page *start_page, + unsigned long size, int node) +{ + return vmemmap_populate_basepages(start_page, size, node); +} +#else /* !CONFIG_ARM64_64K_PAGES */ +int __meminit vmemmap_populate(struct page *start_page, + unsigned long size, int node) +{ + unsigned long addr = (unsigned long)start_page; + unsigned long end = (unsigned long)(start_page + size); + unsigned long next; + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + + do { + next = pmd_addr_end(addr, end); + + pgd = vmemmap_pgd_populate(addr, node); + if (!pgd) + return -ENOMEM; + + pud = vmemmap_pud_populate(pgd, addr, node); + if (!pud) + return -ENOMEM; + + pmd = pmd_offset(pud, addr); + if (pmd_none(*pmd)) { + void *p = NULL; + + p = vmemmap_alloc_block_buf(PMD_SIZE, node); + if (!p) + return -ENOMEM; + + set_pmd(pmd, __pmd(__pa(p) | prot_sect_kernel)); + } else + vmemmap_verify((pte_t *)pmd, node, addr, next); + } while (addr = next, addr != end); + + return 0; +} +#endif /* CONFIG_ARM64_64K_PAGES */ +#endif /* CONFIG_SPARSEMEM_VMEMMAP */