diff options
Diffstat (limited to 'arch/arm64/mm/init.c')
| -rw-r--r-- | arch/arm64/mm/init.c | 504 |
1 files changed, 504 insertions, 0 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c new file mode 100644 index 000000000..4b4651ee4 --- /dev/null +++ b/arch/arm64/mm/init.c @@ -0,0 +1,504 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Based on arch/arm/mm/init.c + * + * Copyright (C) 1995-2005 Russell King + * Copyright (C) 2012 ARM Ltd. + */ + +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/errno.h> +#include <linux/swap.h> +#include <linux/init.h> +#include <linux/cache.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.h> +#include <linux/of_fdt.h> +#include <linux/dma-direct.h> +#include <linux/dma-map-ops.h> +#include <linux/efi.h> +#include <linux/swiotlb.h> +#include <linux/vmalloc.h> +#include <linux/mm.h> +#include <linux/kexec.h> +#include <linux/crash_dump.h> +#include <linux/hugetlb.h> +#include <linux/acpi_iort.h> +#include <linux/kmemleak.h> + +#include <asm/boot.h> +#include <asm/fixmap.h> +#include <asm/kasan.h> +#include <asm/kernel-pgtable.h> +#include <asm/kvm_host.h> +#include <asm/memory.h> +#include <asm/numa.h> +#include <asm/sections.h> +#include <asm/setup.h> +#include <linux/sizes.h> +#include <asm/tlb.h> +#include <asm/alternative.h> +#include <asm/xen/swiotlb-xen.h> + +/* + * We need to be able to catch inadvertent references to memstart_addr + * that occur (potentially in generic code) before arm64_memblock_init() + * executes, which assigns it its actual value. So use a default value + * that cannot be mistaken for a real physical address. + */ +s64 memstart_addr __ro_after_init = -1; +EXPORT_SYMBOL(memstart_addr); + +/* + * If the corresponding config options are enabled, we create both ZONE_DMA + * and ZONE_DMA32. By default ZONE_DMA covers the 32-bit addressable memory + * unless restricted on specific platforms (e.g. 30-bit on Raspberry Pi 4). + * In such case, ZONE_DMA32 covers the rest of the 32-bit addressable memory, + * otherwise it is empty. + * + * Memory reservation for crash kernel either done early or deferred + * depending on DMA memory zones configs (ZONE_DMA) -- + * + * In absence of ZONE_DMA configs arm64_dma_phys_limit initialized + * here instead of max_zone_phys(). This lets early reservation of + * crash kernel memory which has a dependency on arm64_dma_phys_limit. + * Reserving memory early for crash kernel allows linear creation of block + * mappings (greater than page-granularity) for all the memory bank rangs. + * In this scheme a comparatively quicker boot is observed. + * + * If ZONE_DMA configs are defined, crash kernel memory reservation + * is delayed until DMA zone memory range size initialization performed in + * zone_sizes_init(). The defer is necessary to steer clear of DMA zone + * memory range to avoid overlap allocation. So crash kernel memory boundaries + * are not known when mapping all bank memory ranges, which otherwise means + * not possible to exclude crash kernel range from creating block mappings + * so page-granularity mappings are created for the entire memory range. + * Hence a slightly slower boot is observed. + * + * Note: Page-granularity mappings are necessary for crash kernel memory + * range for shrinking its size via /sys/kernel/kexec_crash_size interface. + */ +#if IS_ENABLED(CONFIG_ZONE_DMA) || IS_ENABLED(CONFIG_ZONE_DMA32) +phys_addr_t __ro_after_init arm64_dma_phys_limit; +#else +phys_addr_t __ro_after_init arm64_dma_phys_limit = PHYS_MASK + 1; +#endif + +/* Current arm64 boot protocol requires 2MB alignment */ +#define CRASH_ALIGN SZ_2M + +#define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit +#define CRASH_ADDR_HIGH_MAX (PHYS_MASK + 1) + +static int __init reserve_crashkernel_low(unsigned long long low_size) +{ + unsigned long long low_base; + + low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX); + if (!low_base) { + pr_err("cannot allocate crashkernel low memory (size:0x%llx).\n", low_size); + return -ENOMEM; + } + + pr_info("crashkernel low memory reserved: 0x%08llx - 0x%08llx (%lld MB)\n", + low_base, low_base + low_size, low_size >> 20); + + crashk_low_res.start = low_base; + crashk_low_res.end = low_base + low_size - 1; + insert_resource(&iomem_resource, &crashk_low_res); + + return 0; +} + +/* + * reserve_crashkernel() - reserves memory for crash kernel + * + * This function reserves memory area given in "crashkernel=" kernel command + * line parameter. The memory reserved is used by dump capture kernel when + * primary kernel is crashing. + */ +static void __init reserve_crashkernel(void) +{ + unsigned long long crash_base, crash_size; + unsigned long long crash_low_size = 0; + unsigned long long crash_max = CRASH_ADDR_LOW_MAX; + char *cmdline = boot_command_line; + int ret; + + if (!IS_ENABLED(CONFIG_KEXEC_CORE)) + return; + + /* crashkernel=X[@offset] */ + ret = parse_crashkernel(cmdline, memblock_phys_mem_size(), + &crash_size, &crash_base); + if (ret == -ENOENT) { + ret = parse_crashkernel_high(cmdline, 0, &crash_size, &crash_base); + if (ret || !crash_size) + return; + + /* + * crashkernel=Y,low can be specified or not, but invalid value + * is not allowed. + */ + ret = parse_crashkernel_low(cmdline, 0, &crash_low_size, &crash_base); + if (ret && (ret != -ENOENT)) + return; + + crash_max = CRASH_ADDR_HIGH_MAX; + } else if (ret || !crash_size) { + /* The specified value is invalid */ + return; + } + + crash_size = PAGE_ALIGN(crash_size); + + /* User specifies base address explicitly. */ + if (crash_base) + crash_max = crash_base + crash_size; + + crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, + crash_base, crash_max); + if (!crash_base) { + pr_warn("cannot allocate crashkernel (size:0x%llx)\n", + crash_size); + return; + } + + if ((crash_base >= CRASH_ADDR_LOW_MAX) && + crash_low_size && reserve_crashkernel_low(crash_low_size)) { + memblock_phys_free(crash_base, crash_size); + return; + } + + pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", + crash_base, crash_base + crash_size, crash_size >> 20); + + /* + * The crashkernel memory will be removed from the kernel linear + * map. Inform kmemleak so that it won't try to access it. + */ + kmemleak_ignore_phys(crash_base); + if (crashk_low_res.end) + kmemleak_ignore_phys(crashk_low_res.start); + + crashk_res.start = crash_base; + crashk_res.end = crash_base + crash_size - 1; + insert_resource(&iomem_resource, &crashk_res); +} + +/* + * Return the maximum physical address for a zone accessible by the given bits + * limit. If DRAM starts above 32-bit, expand the zone to the maximum + * available memory, otherwise cap it at 32-bit. + */ +static phys_addr_t __init max_zone_phys(unsigned int zone_bits) +{ + phys_addr_t zone_mask = DMA_BIT_MASK(zone_bits); + phys_addr_t phys_start = memblock_start_of_DRAM(); + + if (phys_start > U32_MAX) + zone_mask = PHYS_ADDR_MAX; + else if (phys_start > zone_mask) + zone_mask = U32_MAX; + + return min(zone_mask, memblock_end_of_DRAM() - 1) + 1; +} + +static void __init zone_sizes_init(void) +{ + unsigned long max_zone_pfns[MAX_NR_ZONES] = {0}; + unsigned int __maybe_unused acpi_zone_dma_bits; + unsigned int __maybe_unused dt_zone_dma_bits; + phys_addr_t __maybe_unused dma32_phys_limit = max_zone_phys(32); + +#ifdef CONFIG_ZONE_DMA + acpi_zone_dma_bits = fls64(acpi_iort_dma_get_max_cpu_address()); + dt_zone_dma_bits = fls64(of_dma_get_max_cpu_address(NULL)); + zone_dma_bits = min3(32U, dt_zone_dma_bits, acpi_zone_dma_bits); + arm64_dma_phys_limit = max_zone_phys(zone_dma_bits); + max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit); +#endif +#ifdef CONFIG_ZONE_DMA32 + max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit); + if (!arm64_dma_phys_limit) + arm64_dma_phys_limit = dma32_phys_limit; +#endif + max_zone_pfns[ZONE_NORMAL] = max_pfn; + + free_area_init(max_zone_pfns); +} + +int pfn_is_map_memory(unsigned long pfn) +{ + phys_addr_t addr = PFN_PHYS(pfn); + + /* avoid false positives for bogus PFNs, see comment in pfn_valid() */ + if (PHYS_PFN(addr) != pfn) + return 0; + + return memblock_is_map_memory(addr); +} +EXPORT_SYMBOL(pfn_is_map_memory); + +static phys_addr_t memory_limit __ro_after_init = PHYS_ADDR_MAX; + +/* + * Limit the memory size that was specified via FDT. + */ +static int __init early_mem(char *p) +{ + if (!p) + return 1; + + memory_limit = memparse(p, &p) & PAGE_MASK; + pr_notice("Memory limited to %lldMB\n", memory_limit >> 20); + + return 0; +} +early_param("mem", early_mem); + +void __init arm64_memblock_init(void) +{ + s64 linear_region_size = PAGE_END - _PAGE_OFFSET(vabits_actual); + + /* + * Corner case: 52-bit VA capable systems running KVM in nVHE mode may + * be limited in their ability to support a linear map that exceeds 51 + * bits of VA space, depending on the placement of the ID map. Given + * that the placement of the ID map may be randomized, let's simply + * limit the kernel's linear map to 51 bits as well if we detect this + * configuration. + */ + if (IS_ENABLED(CONFIG_KVM) && vabits_actual == 52 && + is_hyp_mode_available() && !is_kernel_in_hyp_mode()) { + pr_info("Capping linear region to 51 bits for KVM in nVHE mode on LVA capable hardware.\n"); + linear_region_size = min_t(u64, linear_region_size, BIT(51)); + } + + /* Remove memory above our supported physical address size */ + memblock_remove(1ULL << PHYS_MASK_SHIFT, ULLONG_MAX); + + /* + * Select a suitable value for the base of physical memory. + */ + memstart_addr = round_down(memblock_start_of_DRAM(), + ARM64_MEMSTART_ALIGN); + + if ((memblock_end_of_DRAM() - memstart_addr) > linear_region_size) + pr_warn("Memory doesn't fit in the linear mapping, VA_BITS too small\n"); + + /* + * Remove the memory that we will not be able to cover with the + * linear mapping. Take care not to clip the kernel which may be + * high in memory. + */ + memblock_remove(max_t(u64, memstart_addr + linear_region_size, + __pa_symbol(_end)), ULLONG_MAX); + if (memstart_addr + linear_region_size < memblock_end_of_DRAM()) { + /* ensure that memstart_addr remains sufficiently aligned */ + memstart_addr = round_up(memblock_end_of_DRAM() - linear_region_size, + ARM64_MEMSTART_ALIGN); + memblock_remove(0, memstart_addr); + } + + /* + * If we are running with a 52-bit kernel VA config on a system that + * does not support it, we have to place the available physical + * memory in the 48-bit addressable part of the linear region, i.e., + * we have to move it upward. Since memstart_addr represents the + * physical address of PAGE_OFFSET, we have to *subtract* from it. + */ + if (IS_ENABLED(CONFIG_ARM64_VA_BITS_52) && (vabits_actual != 52)) + memstart_addr -= _PAGE_OFFSET(48) - _PAGE_OFFSET(52); + + /* + * Apply the memory limit if it was set. Since the kernel may be loaded + * high up in memory, add back the kernel region that must be accessible + * via the linear mapping. + */ + if (memory_limit != PHYS_ADDR_MAX) { + memblock_mem_limit_remove_map(memory_limit); + memblock_add(__pa_symbol(_text), (u64)(_end - _text)); + } + + if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) { + /* + * Add back the memory we just removed if it results in the + * initrd to become inaccessible via the linear mapping. + * Otherwise, this is a no-op + */ + u64 base = phys_initrd_start & PAGE_MASK; + u64 size = PAGE_ALIGN(phys_initrd_start + phys_initrd_size) - base; + + /* + * We can only add back the initrd memory if we don't end up + * with more memory than we can address via the linear mapping. + * It is up to the bootloader to position the kernel and the + * initrd reasonably close to each other (i.e., within 32 GB of + * each other) so that all granule/#levels combinations can + * always access both. + */ + if (WARN(base < memblock_start_of_DRAM() || + base + size > memblock_start_of_DRAM() + + linear_region_size, + "initrd not fully accessible via the linear mapping -- please check your bootloader ...\n")) { + phys_initrd_size = 0; + } else { + memblock_add(base, size); + memblock_clear_nomap(base, size); + memblock_reserve(base, size); + } + } + + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { + extern u16 memstart_offset_seed; + u64 mmfr0 = read_cpuid(ID_AA64MMFR0_EL1); + int parange = cpuid_feature_extract_unsigned_field( + mmfr0, ID_AA64MMFR0_EL1_PARANGE_SHIFT); + s64 range = linear_region_size - + BIT(id_aa64mmfr0_parange_to_phys_shift(parange)); + + /* + * If the size of the linear region exceeds, by a sufficient + * margin, the size of the region that the physical memory can + * span, randomize the linear region as well. + */ + if (memstart_offset_seed > 0 && range >= (s64)ARM64_MEMSTART_ALIGN) { + range /= ARM64_MEMSTART_ALIGN; + memstart_addr -= ARM64_MEMSTART_ALIGN * + ((range * memstart_offset_seed) >> 16); + } + } + + /* + * Register the kernel text, kernel data, initrd, and initial + * pagetables with memblock. + */ + memblock_reserve(__pa_symbol(_stext), _end - _stext); + if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) { + /* the generic initrd code expects virtual addresses */ + initrd_start = __phys_to_virt(phys_initrd_start); + initrd_end = initrd_start + phys_initrd_size; + } + + early_init_fdt_scan_reserved_mem(); + + if (!defer_reserve_crashkernel()) + reserve_crashkernel(); + + high_memory = __va(memblock_end_of_DRAM() - 1) + 1; +} + +void __init bootmem_init(void) +{ + unsigned long min, max; + + min = PFN_UP(memblock_start_of_DRAM()); + max = PFN_DOWN(memblock_end_of_DRAM()); + + early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT); + + max_pfn = max_low_pfn = max; + min_low_pfn = min; + + arch_numa_init(); + + /* + * must be done after arch_numa_init() which calls numa_init() to + * initialize node_online_map that gets used in hugetlb_cma_reserve() + * while allocating required CMA size across online nodes. + */ +#if defined(CONFIG_HUGETLB_PAGE) && defined(CONFIG_CMA) + arm64_hugetlb_cma_reserve(); +#endif + + dma_pernuma_cma_reserve(); + + kvm_hyp_reserve(); + + /* + * sparse_init() tries to allocate memory from memblock, so must be + * done after the fixed reservations + */ + sparse_init(); + zone_sizes_init(); + + /* + * Reserve the CMA area after arm64_dma_phys_limit was initialised. + */ + dma_contiguous_reserve(arm64_dma_phys_limit); + + /* + * request_standard_resources() depends on crashkernel's memory being + * reserved, so do it here. + */ + if (defer_reserve_crashkernel()) + reserve_crashkernel(); + + memblock_dump_all(); +} + +/* + * 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) +{ + swiotlb_init(max_pfn > PFN_DOWN(arm64_dma_phys_limit), SWIOTLB_VERBOSE); + + /* this will put all unused low memory onto the freelists */ + memblock_free_all(); + + /* + * Check boundaries twice: Some fundamental inconsistencies can be + * detected at build time already. + */ +#ifdef CONFIG_COMPAT + BUILD_BUG_ON(TASK_SIZE_32 > DEFAULT_MAP_WINDOW_64); +#endif + + /* + * Selected page table levels should match when derived from + * scratch using the virtual address range and page size. + */ + BUILD_BUG_ON(ARM64_HW_PGTABLE_LEVELS(CONFIG_ARM64_VA_BITS) != + CONFIG_PGTABLE_LEVELS); + + if (PAGE_SIZE >= 16384 && get_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) +{ + free_reserved_area(lm_alias(__init_begin), + lm_alias(__init_end), + POISON_FREE_INITMEM, "unused kernel"); + /* + * Unmap the __init region but leave the VM area in place. This + * prevents the region from being reused for kernel modules, which + * is not supported by kallsyms. + */ + vunmap_range((u64)__init_begin, (u64)__init_end); +} + +void dump_mem_limit(void) +{ + if (memory_limit != PHYS_ADDR_MAX) { + pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20); + } else { + pr_emerg("Memory Limit: none\n"); + } +} |