621 lines
15 KiB
C
621 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/arch/arm/mm/init.c
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*
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* Copyright (C) 1995-2005 Russell King
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*/
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/swap.h>
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#include <linux/init.h>
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#include <linux/mman.h>
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#include <linux/sched/signal.h>
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#include <linux/sched/task.h>
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#include <linux/export.h>
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#include <linux/nodemask.h>
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#include <linux/initrd.h>
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#include <linux/of_fdt.h>
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#include <linux/highmem.h>
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#include <linux/gfp.h>
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#include <linux/memblock.h>
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#include <linux/dma-map-ops.h>
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#include <linux/sizes.h>
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#include <linux/stop_machine.h>
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#include <linux/swiotlb.h>
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#include <asm/cp15.h>
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#include <asm/mach-types.h>
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#include <asm/memblock.h>
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#include <asm/memory.h>
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#include <asm/prom.h>
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#include <asm/sections.h>
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#include <asm/setup.h>
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#include <asm/set_memory.h>
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#include <asm/system_info.h>
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#include <asm/tlb.h>
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#include <asm/fixmap.h>
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#include <asm/ptdump.h>
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#include <asm/mach/arch.h>
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#include <asm/mach/map.h>
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#include "mm.h"
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#ifdef CONFIG_CPU_CP15_MMU
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unsigned long __init __clear_cr(unsigned long mask)
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{
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cr_alignment = cr_alignment & ~mask;
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return cr_alignment;
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}
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#endif
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#ifdef CONFIG_BLK_DEV_INITRD
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static int __init parse_tag_initrd(const struct tag *tag)
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{
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pr_warn("ATAG_INITRD is deprecated; "
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"please update your bootloader.\n");
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phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
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phys_initrd_size = tag->u.initrd.size;
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return 0;
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}
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__tagtable(ATAG_INITRD, parse_tag_initrd);
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static int __init parse_tag_initrd2(const struct tag *tag)
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{
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phys_initrd_start = tag->u.initrd.start;
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phys_initrd_size = tag->u.initrd.size;
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return 0;
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}
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__tagtable(ATAG_INITRD2, parse_tag_initrd2);
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#endif
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static void __init find_limits(unsigned long *min, unsigned long *max_low,
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unsigned long *max_high)
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{
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*max_low = PFN_DOWN(memblock_get_current_limit());
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*min = PFN_UP(memblock_start_of_DRAM());
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*max_high = PFN_DOWN(memblock_end_of_DRAM());
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}
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#ifdef CONFIG_ZONE_DMA
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phys_addr_t arm_dma_zone_size __read_mostly;
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EXPORT_SYMBOL(arm_dma_zone_size);
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/*
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* The DMA mask corresponding to the maximum bus address allocatable
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* using GFP_DMA. The default here places no restriction on DMA
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* allocations. This must be the smallest DMA mask in the system,
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* so a successful GFP_DMA allocation will always satisfy this.
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*/
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phys_addr_t arm_dma_limit;
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unsigned long arm_dma_pfn_limit;
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#endif
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void __init setup_dma_zone(const struct machine_desc *mdesc)
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{
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#ifdef CONFIG_ZONE_DMA
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if (mdesc->dma_zone_size) {
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arm_dma_zone_size = mdesc->dma_zone_size;
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arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
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} else
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arm_dma_limit = 0xffffffff;
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arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
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#endif
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}
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static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
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unsigned long max_high)
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{
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unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
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#ifdef CONFIG_ZONE_DMA
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max_zone_pfn[ZONE_DMA] = min(arm_dma_pfn_limit, max_low);
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#endif
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max_zone_pfn[ZONE_NORMAL] = max_low;
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#ifdef CONFIG_HIGHMEM
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max_zone_pfn[ZONE_HIGHMEM] = max_high;
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#endif
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free_area_init(max_zone_pfn);
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}
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#ifdef CONFIG_HAVE_ARCH_PFN_VALID
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int pfn_valid(unsigned long pfn)
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{
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phys_addr_t addr = __pfn_to_phys(pfn);
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if (__phys_to_pfn(addr) != pfn)
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return 0;
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return memblock_is_map_memory(addr);
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}
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EXPORT_SYMBOL(pfn_valid);
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#endif
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static bool arm_memblock_steal_permitted = true;
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phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
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{
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phys_addr_t phys;
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BUG_ON(!arm_memblock_steal_permitted);
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phys = memblock_phys_alloc(size, align);
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if (!phys)
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panic("Failed to steal %pa bytes at %pS\n",
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&size, (void *)_RET_IP_);
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memblock_free(phys, size);
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memblock_remove(phys, size);
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return phys;
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}
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static void __init arm_initrd_init(void)
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{
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#ifdef CONFIG_BLK_DEV_INITRD
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phys_addr_t start;
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unsigned long size;
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initrd_start = initrd_end = 0;
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if (!phys_initrd_size)
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return;
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/*
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* Round the memory region to page boundaries as per free_initrd_mem()
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* This allows us to detect whether the pages overlapping the initrd
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* are in use, but more importantly, reserves the entire set of pages
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* as we don't want these pages allocated for other purposes.
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*/
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start = round_down(phys_initrd_start, PAGE_SIZE);
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size = phys_initrd_size + (phys_initrd_start - start);
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size = round_up(size, PAGE_SIZE);
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if (!memblock_is_region_memory(start, size)) {
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pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
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(u64)start, size);
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return;
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}
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if (memblock_is_region_reserved(start, size)) {
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pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
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(u64)start, size);
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return;
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}
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memblock_reserve(start, size);
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/* Now convert initrd to virtual addresses */
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initrd_start = __phys_to_virt(phys_initrd_start);
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initrd_end = initrd_start + phys_initrd_size;
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#endif
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}
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#ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND
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void check_cpu_icache_size(int cpuid)
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{
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u32 size, ctr;
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asm("mrc p15, 0, %0, c0, c0, 1" : "=r" (ctr));
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size = 1 << ((ctr & 0xf) + 2);
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if (cpuid != 0 && icache_size != size)
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pr_info("CPU%u: detected I-Cache line size mismatch, workaround enabled\n",
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cpuid);
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if (icache_size > size)
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icache_size = size;
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}
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#endif
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void __init arm_memblock_init(const struct machine_desc *mdesc)
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{
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/* Register the kernel text, kernel data and initrd with memblock. */
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memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START);
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arm_initrd_init();
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arm_mm_memblock_reserve();
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/* reserve any platform specific memblock areas */
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if (mdesc->reserve)
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mdesc->reserve();
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early_init_fdt_reserve_self();
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early_init_fdt_scan_reserved_mem();
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/* reserve memory for DMA contiguous allocations */
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dma_contiguous_reserve(arm_dma_limit);
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arm_memblock_steal_permitted = false;
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memblock_dump_all();
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}
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void __init bootmem_init(void)
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{
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memblock_allow_resize();
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find_limits(&min_low_pfn, &max_low_pfn, &max_pfn);
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early_memtest((phys_addr_t)min_low_pfn << PAGE_SHIFT,
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(phys_addr_t)max_low_pfn << PAGE_SHIFT);
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/*
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* sparse_init() tries to allocate memory from memblock, so must be
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* done after the fixed reservations
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*/
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sparse_init();
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/*
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* Now free the memory - free_area_init needs
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* the sparse mem_map arrays initialized by sparse_init()
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* for memmap_init_zone(), otherwise all PFNs are invalid.
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*/
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zone_sizes_init(min_low_pfn, max_low_pfn, max_pfn);
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}
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/*
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* Poison init memory with an undefined instruction (ARM) or a branch to an
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* undefined instruction (Thumb).
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*/
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static inline void poison_init_mem(void *s, size_t count)
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{
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u32 *p = (u32 *)s;
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for (; count != 0; count -= 4)
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*p++ = 0xe7fddef0;
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}
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static inline void __init
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free_memmap(unsigned long start_pfn, unsigned long end_pfn)
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{
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struct page *start_pg, *end_pg;
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phys_addr_t pg, pgend;
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/*
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* Convert start_pfn/end_pfn to a struct page pointer.
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*/
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start_pg = pfn_to_page(start_pfn - 1) + 1;
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end_pg = pfn_to_page(end_pfn - 1) + 1;
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/*
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* Convert to physical addresses, and
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* round start upwards and end downwards.
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*/
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pg = PAGE_ALIGN(__pa(start_pg));
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pgend = __pa(end_pg) & PAGE_MASK;
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/*
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* If there are free pages between these,
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* free the section of the memmap array.
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*/
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if (pg < pgend)
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memblock_free_early(pg, pgend - pg);
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}
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/*
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* The mem_map array can get very big. Free the unused area of the memory map.
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*/
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static void __init free_unused_memmap(void)
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{
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unsigned long start, end, prev_end = 0;
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int i;
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/*
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* This relies on each bank being in address order.
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* The banks are sorted previously in bootmem_init().
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*/
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for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) {
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#ifdef CONFIG_SPARSEMEM
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/*
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* Take care not to free memmap entries that don't exist
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* due to SPARSEMEM sections which aren't present.
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*/
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start = min(start,
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ALIGN(prev_end, PAGES_PER_SECTION));
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#else
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/*
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* Align down here since the VM subsystem insists that the
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* memmap entries are valid from the bank start aligned to
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* MAX_ORDER_NR_PAGES.
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*/
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start = round_down(start, MAX_ORDER_NR_PAGES);
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#endif
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/*
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* If we had a previous bank, and there is a space
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* between the current bank and the previous, free it.
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*/
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if (prev_end && prev_end < start)
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free_memmap(prev_end, start);
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/*
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* Align up here since the VM subsystem insists that the
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* memmap entries are valid from the bank end aligned to
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* MAX_ORDER_NR_PAGES.
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*/
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prev_end = ALIGN(end, MAX_ORDER_NR_PAGES);
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}
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#ifdef CONFIG_SPARSEMEM
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if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
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free_memmap(prev_end,
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ALIGN(prev_end, PAGES_PER_SECTION));
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#endif
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}
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static void __init free_highpages(void)
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{
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#ifdef CONFIG_HIGHMEM
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unsigned long max_low = max_low_pfn;
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phys_addr_t range_start, range_end;
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u64 i;
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/* set highmem page free */
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for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
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&range_start, &range_end, NULL) {
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unsigned long start = PFN_UP(range_start);
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unsigned long end = PFN_DOWN(range_end);
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/* Ignore complete lowmem entries */
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if (end <= max_low)
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continue;
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/* Truncate partial highmem entries */
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if (start < max_low)
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start = max_low;
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for (; start < end; start++)
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free_highmem_page(pfn_to_page(start));
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}
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#endif
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}
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/*
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* mem_init() marks the free areas in the mem_map and tells us how much
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* memory is free. This is done after various parts of the system have
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* claimed their memory after the kernel image.
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*/
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void __init mem_init(void)
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{
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#ifdef CONFIG_ARM_LPAE
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swiotlb_init(1);
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#endif
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set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
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/* this will put all unused low memory onto the freelists */
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free_unused_memmap();
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memblock_free_all();
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#ifdef CONFIG_SA1111
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/* now that our DMA memory is actually so designated, we can free it */
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free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
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#endif
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free_highpages();
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mem_init_print_info(NULL);
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/*
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* Check boundaries twice: Some fundamental inconsistencies can
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* be detected at build time already.
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*/
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#ifdef CONFIG_MMU
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BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
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BUG_ON(TASK_SIZE > MODULES_VADDR);
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#endif
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#ifdef CONFIG_HIGHMEM
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BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
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BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
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#endif
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}
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#ifdef CONFIG_STRICT_KERNEL_RWX
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struct section_perm {
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const char *name;
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unsigned long start;
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unsigned long end;
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pmdval_t mask;
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pmdval_t prot;
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pmdval_t clear;
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};
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/* First section-aligned location at or after __start_rodata. */
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extern char __start_rodata_section_aligned[];
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static struct section_perm nx_perms[] = {
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/* Make pages tables, etc before _stext RW (set NX). */
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{
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.name = "pre-text NX",
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.start = PAGE_OFFSET,
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.end = (unsigned long)_stext,
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.mask = ~PMD_SECT_XN,
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.prot = PMD_SECT_XN,
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},
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/* Make init RW (set NX). */
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{
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.name = "init NX",
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.start = (unsigned long)__init_begin,
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.end = (unsigned long)_sdata,
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.mask = ~PMD_SECT_XN,
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.prot = PMD_SECT_XN,
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},
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/* Make rodata NX (set RO in ro_perms below). */
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{
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.name = "rodata NX",
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.start = (unsigned long)__start_rodata_section_aligned,
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.end = (unsigned long)__init_begin,
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.mask = ~PMD_SECT_XN,
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.prot = PMD_SECT_XN,
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},
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};
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static struct section_perm ro_perms[] = {
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/* Make kernel code and rodata RX (set RO). */
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{
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.name = "text/rodata RO",
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.start = (unsigned long)_stext,
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.end = (unsigned long)__init_begin,
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#ifdef CONFIG_ARM_LPAE
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.mask = ~(L_PMD_SECT_RDONLY | PMD_SECT_AP2),
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.prot = L_PMD_SECT_RDONLY | PMD_SECT_AP2,
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#else
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.mask = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE),
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.prot = PMD_SECT_APX | PMD_SECT_AP_WRITE,
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.clear = PMD_SECT_AP_WRITE,
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#endif
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},
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};
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/*
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* Updates section permissions only for the current mm (sections are
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* copied into each mm). During startup, this is the init_mm. Is only
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* safe to be called with preemption disabled, as under stop_machine().
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*/
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static inline void section_update(unsigned long addr, pmdval_t mask,
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pmdval_t prot, struct mm_struct *mm)
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{
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pmd_t *pmd;
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pmd = pmd_offset(pud_offset(p4d_offset(pgd_offset(mm, addr), addr), addr), addr);
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#ifdef CONFIG_ARM_LPAE
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pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
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#else
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if (addr & SECTION_SIZE)
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pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot);
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else
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pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
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#endif
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flush_pmd_entry(pmd);
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local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE);
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}
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/* Make sure extended page tables are in use. */
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static inline bool arch_has_strict_perms(void)
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{
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if (cpu_architecture() < CPU_ARCH_ARMv6)
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return false;
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return !!(get_cr() & CR_XP);
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}
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static void set_section_perms(struct section_perm *perms, int n, bool set,
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struct mm_struct *mm)
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{
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size_t i;
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unsigned long addr;
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if (!arch_has_strict_perms())
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return;
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for (i = 0; i < n; i++) {
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if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
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!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
|