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Subject[PATCH 11/36] AArch64: 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/aarch64/include/asm/memblock.h | 24 ++
arch/aarch64/mm/init.c | 575 +++++++++++++++++++++++++++++++++++
arch/aarch64/mm/mmu.c | 464 ++++++++++++++++++++++++++++
3 files changed, 1063 insertions(+), 0 deletions(-)
create mode 100644 arch/aarch64/include/asm/memblock.h
create mode 100644 arch/aarch64/mm/init.c
create mode 100644 arch/aarch64/mm/mmu.c

diff --git a/arch/aarch64/include/asm/memblock.h b/arch/aarch64/include/asm/memblock.h
new file mode 100644
index 0000000..33176ba
--- /dev/null
+++ b/arch/aarch64/include/asm/memblock.h
@@ -0,0 +1,24 @@
+/*
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifndef __ASM_MEMBLOCK_H
+#define __ASM_MEMBLOCK_H
+
+struct meminfo;
+
+extern void aarch64_memblock_init(struct meminfo *);
+
+#endif
diff --git a/arch/aarch64/mm/init.c b/arch/aarch64/mm/init.c
new file mode 100644
index 0000000..21674c1
--- /dev/null
+++ b/arch/aarch64/mm/init.c
@@ -0,0 +1,575 @@
+/*
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#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);
+
+/*
+ * This keeps memory configuration data used by a couple memory initialization
+ * functions, as well as show_mem() for the skipping of holes in the memory
+ * map. It is populated by arm_add_memory().
+ */
+struct meminfo meminfo;
+
+void show_mem(unsigned int filter)
+{
+ int free = 0, total = 0, reserved = 0;
+ int shared = 0, cached = 0, slab = 0, i;
+ struct meminfo * mi = &meminfo;
+
+ printk("Mem-info:\n");
+ show_free_areas(filter);
+
+ for_each_bank (i, mi) {
+ struct membank *bank = &mi->bank[i];
+ unsigned int pfn1, pfn2;
+ struct page *page, *end;
+
+ pfn1 = bank_pfn_start(bank);
+ pfn2 = bank_pfn_end(bank);
+
+ page = pfn_to_page(pfn1);
+ end = pfn_to_page(pfn2 - 1) + 1;
+
+ do {
+ total++;
+ if (PageReserved(page))
+ reserved++;
+ else if (PageSwapCache(page))
+ cached++;
+ else if (PageSlab(page))
+ slab++;
+ else if (!page_count(page))
+ free++;
+ else
+ shared += page_count(page) - 1;
+ page++;
+ } while (page < end);
+ }
+
+ printk("%d pages of RAM\n", total);
+ printk("%d free pages\n", free);
+ printk("%d reserved pages\n", reserved);
+ printk("%d slab pages\n", slab);
+ printk("%d pages shared\n", shared);
+ printk("%d pages swap cached\n", cached);
+}
+
+static void __init find_limits(unsigned long *min, unsigned long *max)
+{
+ struct meminfo *mi = &meminfo;
+ int i;
+
+ *min = -1UL;
+ *max = 0;
+
+ for_each_bank (i, mi) {
+ struct membank *bank = &mi->bank[i];
+ unsigned long start, end;
+
+ start = bank_pfn_start(bank);
+ end = bank_pfn_end(bank);
+
+ if (*min > start)
+ *min = start;
+ if (*max < end)
+ *max = end;
+ }
+}
+
+static void __init aarch64_bootmem_init(unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ struct memblock_region *reg;
+ unsigned int boot_pages;
+ phys_addr_t bitmap;
+ pg_data_t *pgdat;
+
+ /*
+ * Allocate the bootmem bitmap page. This must be in a region of
+ * memory which has already been mapped.
+ */
+ boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
+ bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
+ __pfn_to_phys(end_pfn));
+
+ /*
+ * Initialise the bootmem allocator, handing the memory banks over to
+ * bootmem.
+ */
+ node_set_online(0);
+ pgdat = NODE_DATA(0);
+ init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);
+
+ /* Free the memory regions from memblock into bootmem */
+ for_each_memblock(memory, reg) {
+ unsigned long start = memblock_region_memory_base_pfn(reg);
+ unsigned long end = memblock_region_memory_end_pfn(reg);
+
+ if (end >= end_pfn)
+ end = end_pfn;
+ if (start >= end)
+ break;
+
+ free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT);
+ }
+
+ /* Reserve the memblock reserved regions in bootmem */
+ for_each_memblock(reserved, reg) {
+ unsigned long start = memblock_region_reserved_base_pfn(reg);
+ unsigned long end = memblock_region_reserved_end_pfn(reg);
+
+ if (end >= end_pfn)
+ end = end_pfn;
+ if (start >= end)
+ break;
+
+ reserve_bootmem(__pfn_to_phys(start),
+ (end - start) << PAGE_SHIFT, BOOTMEM_DEFAULT);
+ }
+}
+
+static void __init aarch64_bootmem_free(unsigned long min, unsigned long max)
+{
+ 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 - min;
+
+ /*
+ * 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) {
+ unsigned long low_end = min(end, max);
+ zhole_size[0] -= low_end - start;
+ }
+ }
+
+ free_area_init_node(0, zone_size, min, zhole_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 aarch64_memory_present(void)
+{
+}
+#else
+static void aarch64_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
+
+static int __init meminfo_cmp(const void *_a, const void *_b)
+{
+ const struct membank *a = _a, *b = _b;
+ long cmp = bank_pfn_start(a) - bank_pfn_start(b);
+ return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
+}
+
+void __init aarch64_memblock_init(struct meminfo *mi)
+{
+ int i;
+
+ sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]),
+ meminfo_cmp, NULL);
+
+ for (i = 0; i < mi->nr_banks; i++)
+ memblock_add(mi->bank[i].start, mi->bank[i].size);
+
+ /* Register the kernel text, kernel data and initrd with memblock */
+ memblock_reserve(__pa(_stext), _end - _stext);
+#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
+
+ aarch64_mm_memblock_reserve();
+ dt_memblock_reserve();
+
+ memblock_allow_resize();
+ memblock_dump_all();
+}
+
+void __init bootmem_init(void)
+{
+ unsigned long min, max;
+
+ find_limits(&min, &max);
+
+ aarch64_bootmem_init(min, max);
+
+ /*
+ * Sparsemem tries to allocate bootmem in memory_present(), so must be
+ * done after the fixed reservations.
+ */
+ aarch64_memory_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.
+ */
+ aarch64_bootmem_free(min, max);
+
+ high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
+
+ /*
+ * This doesn't seem to be used by the Linux memory manager any more,
+ * but is used by ll_rw_block. If we can get rid of it, we also get
+ * rid of some of the stuff above as well.
+ *
+ * Note: max_low_pfn and max_pfn reflect the number of _pages_ in the
+ * system, not the maximum PFN.
+ */
+ max_pfn = max_low_pfn = max - PHYS_PFN_OFFSET;
+}
+
+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(struct meminfo *mi)
+{
+ unsigned long bank_start, prev_bank_end = 0;
+ unsigned int i;
+
+ /*
+ * This relies on each bank being in address order. The banks are
+ * sorted previously in bootmem_init().
+ */
+ for_each_bank(i, mi) {
+ struct membank *bank = &mi->bank[i];
+
+ bank_start = bank_pfn_start(bank);
+
+#ifdef CONFIG_SPARSEMEM
+ /*
+ * Take care not to free memmap entries that don't exist due
+ * to SPARSEMEM sections which aren't present.
+ */
+ bank_start = min(bank_start,
+ ALIGN(prev_bank_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_bank_end && prev_bank_end < bank_start)
+ free_memmap(prev_bank_end, bank_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_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES);
+ }
+
+#ifdef CONFIG_SPARSEMEM
+ if (!IS_ALIGNED(prev_bank_end, PAGES_PER_SECTION))
+ free_memmap(prev_bank_end,
+ ALIGN(prev_bank_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;
+ int i;
+
+#if CONFIG_SWIOTLB
+ extern void __init aarch64_swiotlb_init(size_t max_size);
+ aarch64_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(&meminfo);
+#endif
+
+ totalram_pages += free_all_bootmem();
+
+ reserved_pages = free_pages = 0;
+
+ for_each_bank(i, &meminfo) {
+ struct membank *bank = &meminfo.bank[i];
+ unsigned int pfn1, pfn2;
+ struct page *page, *end;
+
+ pfn1 = bank_pfn_start(bank);
+ pfn2 = bank_pfn_end(bank);
+
+ 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/aarch64/mm/mmu.c b/arch/aarch64/mm/mmu.c
new file mode 100644
index 0000000..518bf9f
--- /dev/null
+++ b/arch/aarch64/mm/mmu.c
@@ -0,0 +1,464 @@
+/*
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#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);
+
+struct map_desc {
+ unsigned long virtual;
+ unsigned long pfn;
+ unsigned long length;
+ unsigned int type;
+};
+
+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);
+
+#define PROT_PTE_DEVICE PTE_TYPE_PAGE | PTE_AF | PTE_DIRTY | PTE_XN
+#define PROT_SECT_DEVICE PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_XN
+
+#define PROT_PTE_NORMAL PTE_TYPE_PAGE | PTE_AF | PTE_DIRTY
+#define PROT_SECT_NORMAL PMD_TYPE_SECT | PMD_SECT_AF
+
+static struct mem_type mem_types[] = {
+ [MT_DEVICE_nGnRnE] = {
+ .prot_pte = PROT_PTE_DEVICE | PTE_ATTRINDX(MT_DEVICE_nGnRnE),
+ .prot_sect = PROT_SECT_DEVICE | PMD_ATTRINDX(MT_DEVICE_nGnRnE),
+ },
+ [MT_DEVICE_nGnRE] = {
+ .prot_pte = PROT_PTE_DEVICE | PTE_ATTRINDX(MT_DEVICE_nGnRE),
+ .prot_sect = PROT_SECT_DEVICE | PMD_ATTRINDX(MT_DEVICE_nGnRE),
+ },
+ [MT_DEVICE_GRE] = {
+ .prot_pte = PROT_PTE_DEVICE | PTE_ATTRINDX(MT_DEVICE_GRE),
+ .prot_sect = PROT_SECT_DEVICE | PMD_ATTRINDX(MT_DEVICE_GRE),
+ },
+ [MT_NORMAL_NC] = {
+ .prot_pte = PROT_PTE_NORMAL | PTE_ATTRINDX(MT_NORMAL_NC),
+ .prot_sect = PROT_SECT_NORMAL | PMD_ATTRINDX(MT_NORMAL_NC),
+ },
+ [MT_NORMAL] = {
+ .prot_pte = PROT_PTE_NORMAL | PTE_ATTRINDX(MT_NORMAL),
+ .prot_sect = PROT_SECT_NORMAL | PMD_ATTRINDX(MT_NORMAL),
+ },
+};
+
+const struct mem_type *get_mem_type(unsigned int type)
+{
+ return type < ARRAY_SIZE(mem_types) ? &mem_types[type] : NULL;
+}
+
+/*
+ * Adjust the PMD section entries according to the CPU in use.
+ */
+static void __init build_mem_type_table(void)
+{
+ pteval_t default_pgprot;
+ int i;
+
+ default_pgprot = PTE_ATTRINDX(MT_NORMAL);
+
+#ifdef CONFIG_SMP
+ /*
+ * Mark memory with the "shared" attribute for SMP systems
+ */
+ default_pgprot |= PTE_SHARED;
+ mem_types[MT_NORMAL].prot_pte |= PTE_SHARED;
+ mem_types[MT_NORMAL].prot_sect |= PMD_SECT_S;
+ mem_types[MT_NORMAL_NC].prot_pte |= PTE_SHARED;
+ mem_types[MT_NORMAL_NC].prot_sect |= 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,
+ const struct mem_type *type)
+{
+ 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, __pgprot(type->prot_pte)));
+ 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,
+ const struct mem_type *type)
+{
+ 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 | type->prot_sect));
+ else
+ alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys),
+ type);
+ 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,
+ const struct mem_type *type)
+{
+ pud_t *pud = pud_offset(pgd, addr);
+ unsigned long next;
+
+ do {
+ next = pud_addr_end(addr, end);
+ alloc_init_pmd(pud, addr, next, phys, type);
+ 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(struct map_desc *md)
+{
+ unsigned long addr, length, end, next;
+ phys_addr_t phys;
+ const struct mem_type *type;
+ pgd_t *pgd;
+
+ if (md->virtual < VMALLOC_START) {
+ pr_warning("BUG: not creating mapping for 0x%016llx at 0x%016lx - outside kernel range\n",
+ __pfn_to_phys(md->pfn), md->virtual);
+ return;
+ }
+
+ type = &mem_types[md->type];
+
+ addr = md->virtual & PAGE_MASK;
+ phys = __pfn_to_phys(md->pfn);
+ length = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
+
+ pgd = pgd_offset_k(addr);
+ end = addr + length;
+ do {
+ next = pgd_addr_end(addr, end);
+ alloc_init_pud(pgd, addr, next, phys, type);
+ phys += next - addr;
+ } while (pgd++, addr = next, addr != end);
+}
+
+/*
+ * Reserve the special regions of memory.
+ */
+void __init aarch64_mm_memblock_reserve(void)
+{
+ /*
+ * 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);
+}
+
+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;
+ struct map_desc map;
+
+ if (start >= end)
+ break;
+
+ map.pfn = __phys_to_pfn(start);
+ map.virtual = __phys_to_virt(start);
+ map.length = end - start;
+ map.type = MT_NORMAL;
+
+ create_mapping(&map);
+ }
+}
+
+/*
+ * 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);
+
+ build_mem_type_table();
+ 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_AARCH64_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_AARCH64_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) | mem_types[MT_NORMAL].prot_sect));
+ } else
+ vmemmap_verify((pte_t *)pmd, node, addr, next);
+ } while (addr = next, addr != end);
+
+ return 0;
+}
+#endif /* CONFIG_AARCH64_64K_PAGES */
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */


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