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    Subject[PATCH v2 05/31] arm64: MMU initialisation
    Date
    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 <will.deacon@arm.com>
    Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
    ---
    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 <http://www.gnu.org/licenses/>.
    + */
    +#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..c87583d
    --- /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 <http://www.gnu.org/licenses/>.
    + */
    +
    +#include <linux/kernel.h>
    +#include <linux/export.h>
    +#include <linux/errno.h>
    +#include <linux/swap.h>
    +#include <linux/init.h>
    +#include <linux/bootmem.h>
    +#include <linux/mman.h>
    +#include <linux/nodemask.h>
    +#include <linux/initrd.h>
    +#include <linux/gfp.h>
    +#include <linux/memblock.h>
    +#include <linux/sort.h>
    +#include <linux/of_fdt.h>
    +
    +#include <asm/prom.h>
    +#include <asm/sections.h>
    +#include <asm/setup.h>
    +#include <asm/sizes.h>
    +#include <asm/tlb.h>
    +
    +#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_AARCH32_EMULATION
    + 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 <http://www.gnu.org/licenses/>.
    + */
    +
    +#include <linux/export.h>
    +#include <linux/kernel.h>
    +#include <linux/errno.h>
    +#include <linux/init.h>
    +#include <linux/mman.h>
    +#include <linux/nodemask.h>
    +#include <linux/memblock.h>
    +#include <linux/fs.h>
    +
    +#include <asm/cputype.h>
    +#include <asm/sections.h>
    +#include <asm/setup.h>
    +#include <asm/sizes.h>
    +#include <asm/tlb.h>
    +#include <asm/mmu_context.h>
    +
    +#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 */


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      Last update: 2012-08-14 20:42    [W:3.765 / U:0.012 seconds]
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