blob: e631e6425165bde29e4daefea599045f750a90e3 [file] [log] [blame]
// 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-mapping.h>
#include <linux/dma-contiguous.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 <asm/boot.h>
#include <asm/fixmap.h>
#include <asm/kasan.h>
#include <asm/kernel-pgtable.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>
#define ARM64_ZONE_DMA_BITS 30
/*
* 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);
s64 physvirt_offset __ro_after_init;
EXPORT_SYMBOL(physvirt_offset);
struct page *vmemmap __ro_after_init;
EXPORT_SYMBOL(vmemmap);
/*
* We create both ZONE_DMA and ZONE_DMA32. ZONE_DMA covers the first 1G of
* memory as some devices, namely the Raspberry Pi 4, have peripherals with
* this limited view of the memory. ZONE_DMA32 will cover the rest of the 32
* bit addressable memory area.
*/
phys_addr_t arm64_dma_phys_limit __ro_after_init;
static phys_addr_t arm64_dma32_phys_limit __ro_after_init;
#ifdef CONFIG_KEXEC_CORE
/*
* 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;
int ret;
ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
&crash_size, &crash_base);
/* no crashkernel= or invalid value specified */
if (ret || !crash_size)
return;
crash_size = PAGE_ALIGN(crash_size);
if (crash_base == 0) {
/* Current arm64 boot protocol requires 2MB alignment */
crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit,
crash_size, SZ_2M);
if (crash_base == 0) {
pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
crash_size);
return;
}
} else {
/* User specifies base address explicitly. */
if (!memblock_is_region_memory(crash_base, crash_size)) {
pr_warn("cannot reserve crashkernel: region is not memory\n");
return;
}
if (memblock_is_region_reserved(crash_base, crash_size)) {
pr_warn("cannot reserve crashkernel: region overlaps reserved memory\n");
return;
}
if (!IS_ALIGNED(crash_base, SZ_2M)) {
pr_warn("cannot reserve crashkernel: base address is not 2MB aligned\n");
return;
}
}
memblock_reserve(crash_base, crash_size);
pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
crash_base, crash_base + crash_size, crash_size >> 20);
crashk_res.start = crash_base;
crashk_res.end = crash_base + crash_size - 1;
}
#else
static void __init reserve_crashkernel(void)
{
}
#endif /* CONFIG_KEXEC_CORE */
#ifdef CONFIG_CRASH_DUMP
static int __init early_init_dt_scan_elfcorehdr(unsigned long node,
const char *uname, int depth, void *data)
{
const __be32 *reg;
int len;
if (depth != 1 || strcmp(uname, "chosen") != 0)
return 0;
reg = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);
if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells)))
return 1;
elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &reg);
elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &reg);
return 1;
}
/*
* reserve_elfcorehdr() - reserves memory for elf core header
*
* This function reserves the memory occupied by an elf core header
* described in the device tree. This region contains all the
* information about primary kernel's core image and is used by a dump
* capture kernel to access the system memory on primary kernel.
*/
static void __init reserve_elfcorehdr(void)
{
of_scan_flat_dt(early_init_dt_scan_elfcorehdr, NULL);
if (!elfcorehdr_size)
return;
if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
pr_warn("elfcorehdr is overlapped\n");
return;
}
memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
pr_info("Reserving %lldKB of memory at 0x%llx for elfcorehdr\n",
elfcorehdr_size >> 10, elfcorehdr_addr);
}
#else
static void __init reserve_elfcorehdr(void)
{
}
#endif /* CONFIG_CRASH_DUMP */
/*
* Return the maximum physical address for a zone with a given address size
* limit. It currently assumes that for memory starting above 4G, 32-bit
* devices will use a DMA offset.
*/
static phys_addr_t __init max_zone_phys(unsigned int zone_bits)
{
phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, zone_bits);
return min(offset + (1ULL << zone_bits), memblock_end_of_DRAM());
}
static void __init zone_sizes_init(unsigned long min, unsigned long max)
{
unsigned long max_zone_pfns[MAX_NR_ZONES] = {0};
#ifdef CONFIG_ZONE_DMA
max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit);
#endif
#ifdef CONFIG_ZONE_DMA32
max_zone_pfns[ZONE_DMA32] = PFN_DOWN(arm64_dma32_phys_limit);
#endif
max_zone_pfns[ZONE_NORMAL] = max;
free_area_init(max_zone_pfns);
}
int pfn_valid(unsigned long pfn)
{
phys_addr_t addr = pfn << PAGE_SHIFT;
if ((addr >> PAGE_SHIFT) != pfn)
return 0;
#ifdef CONFIG_SPARSEMEM
if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
return 0;
if (!valid_section(__pfn_to_section(pfn)))
return 0;
#endif
return memblock_is_map_memory(addr);
}
EXPORT_SYMBOL(pfn_valid);
static phys_addr_t memory_limit = 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);
static int __init early_init_dt_scan_usablemem(unsigned long node,
const char *uname, int depth, void *data)
{
struct memblock_region *usablemem = data;
const __be32 *reg;
int len;
if (depth != 1 || strcmp(uname, "chosen") != 0)
return 0;
reg = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);
if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells)))
return 1;
usablemem->base = dt_mem_next_cell(dt_root_addr_cells, &reg);
usablemem->size = dt_mem_next_cell(dt_root_size_cells, &reg);
return 1;
}
static void __init fdt_enforce_memory_region(void)
{
struct memblock_region reg = {
.size = 0,
};
of_scan_flat_dt(early_init_dt_scan_usablemem, &reg);
if (reg.size)
memblock_cap_memory_range(reg.base, reg.size);
}
void __init arm64_memblock_init(void)
{
const s64 linear_region_size = BIT(vabits_actual - 1);
/* Handle linux,usable-memory-range property */
fdt_enforce_memory_region();
/* 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);
physvirt_offset = PHYS_OFFSET - PAGE_OFFSET;
vmemmap = ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT));
/*
* If we are running with a 52-bit kernel VA config on a system that
* does not support it, we have to offset our vmemmap and physvirt_offset
* s.t. we avoid the 52-bit portion of the direct linear map
*/
if (IS_ENABLED(CONFIG_ARM64_VA_BITS_52) && (vabits_actual != 52)) {
vmemmap += (_PAGE_OFFSET(48) - _PAGE_OFFSET(52)) >> PAGE_SHIFT;
physvirt_offset = PHYS_OFFSET - _PAGE_OFFSET(48);
}
/*
* 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);
}
/*
* 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 range = linear_region_size -
(memblock_end_of_DRAM() - memblock_start_of_DRAM());
/*
* If the size of the linear region exceeds, by a sufficient
* margin, the size of the region that the available physical
* memory spans, randomize the linear region as well.
*/
if (memstart_offset_seed > 0 && range >= 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(_text), _end - _text);
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)) {
zone_dma_bits = ARM64_ZONE_DMA_BITS;
arm64_dma_phys_limit = max_zone_phys(ARM64_ZONE_DMA_BITS);
}
if (IS_ENABLED(CONFIG_ZONE_DMA32))
arm64_dma32_phys_limit = max_zone_phys(32);
else
arm64_dma32_phys_limit = PHYS_MASK + 1;
reserve_crashkernel();
reserve_elfcorehdr();
high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
dma_contiguous_reserve(arm64_dma32_phys_limit);
#ifdef CONFIG_ARM64_4K_PAGES
hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
#endif
}
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;
arm64_numa_init();
/*
* Sparsemem tries to allocate bootmem in memory_present(), so must be
* done after the fixed reservations.
*/
memblocks_present();
sparse_init();
zone_sizes_init(min, max);
memblock_dump_all();
}
#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)
memblock_free(pg, pgend - pg);
}
/*
* The mem_map array can get very big. Free the unused area of the memory map.
*/
static void __init free_unused_memmap(void)
{
unsigned long start, prev_end = 0;
struct memblock_region *reg;
for_each_memblock(memory, reg) {
start = __phys_to_pfn(reg->base);
#ifdef CONFIG_SPARSEMEM
/*
* Take care not to free memmap entries that don't exist due
* to SPARSEMEM sections which aren't present.
*/
start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
#endif
/*
* If we had a previous bank, and there is a space between the
* current bank and the previous, free it.
*/
if (prev_end && prev_end < start)
free_memmap(prev_end, start);
/*
* Align up here since the VM subsystem insists that the
* memmap entries are valid from the bank end aligned to
* MAX_ORDER_NR_PAGES.
*/
prev_end = ALIGN(__phys_to_pfn(reg->base + reg->size),
MAX_ORDER_NR_PAGES);
}
#ifdef CONFIG_SPARSEMEM
if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
#endif
}
#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
/*
* mem_init() marks the free areas in the mem_map and tells us how much memory
* is free. This is done after various parts of the system have claimed their
* memory after the kernel image.
*/
void __init mem_init(void)
{
if (swiotlb_force == SWIOTLB_FORCE ||
max_pfn > PFN_DOWN(arm64_dma_phys_limit ? : arm64_dma32_phys_limit))
swiotlb_init(1);
else
swiotlb_force = SWIOTLB_NO_FORCE;
set_max_mapnr(max_pfn - PHYS_PFN_OFFSET);
#ifndef CONFIG_SPARSEMEM_VMEMMAP
free_unused_memmap();
#endif
/* this will put all unused low memory onto the freelists */
memblock_free_all();
mem_init_print_info(NULL);
/*
* 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
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.
*/
unmap_kernel_range((u64)__init_begin, (u64)(__init_end - __init_begin));
}
/*
* Dump out memory limit information on panic.
*/
static int dump_mem_limit(struct notifier_block *self, unsigned long v, void *p)
{
if (memory_limit != PHYS_ADDR_MAX) {
pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20);
} else {
pr_emerg("Memory Limit: none\n");
}
return 0;
}
static struct notifier_block mem_limit_notifier = {
.notifier_call = dump_mem_limit,
};
static int __init register_mem_limit_dumper(void)
{
atomic_notifier_chain_register(&panic_notifier_list,
&mem_limit_notifier);
return 0;
}
__initcall(register_mem_limit_dumper);