| // 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_remove(base, size); /* clear MEMBLOCK_ flags */ |
| memblock_add(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_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 (!IS_ENABLED(CONFIG_ZONE_DMA) && !IS_ENABLED(CONFIG_ZONE_DMA32)) |
| 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 (IS_ENABLED(CONFIG_ZONE_DMA) || IS_ENABLED(CONFIG_ZONE_DMA32)) |
| 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"); |
| } |
| } |