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tegrakernel/kernel/kernel-4.9/arch/arm64/mm/init.c

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/*
* 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, see <http://www.gnu.org/licenses/>.
*/
#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/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_fdt.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 <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 <asm/sizes.h>
#include <asm/tlb.h>
#include <asm/alternative.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;
phys_addr_t arm64_dma_phys_limit __ro_after_init;
#ifdef CONFIG_BLK_DEV_INITRD
static int __init early_initrd(char *p)
{
unsigned long start, size;
char *endp;
start = memparse(p, &endp);
if (*endp == ',') {
size = memparse(endp + 1, NULL);
initrd_start = start;
initrd_end = start + size;
}
return 0;
}
early_param("initrd", early_initrd);
#endif
/*
* Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
* currently assumes that for memory starting above 4G, 32-bit devices will
* use a DMA offset.
*/
static phys_addr_t __init max_zone_dma_phys(void)
{
phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
return min(offset + (1ULL << 32), memblock_end_of_DRAM());
}
#ifdef CONFIG_NUMA
static void __init zone_sizes_init(unsigned long min, unsigned long max)
{
unsigned long max_zone_pfns[MAX_NR_ZONES] = {0};
if (IS_ENABLED(CONFIG_ZONE_DMA))
max_zone_pfns[ZONE_DMA] = PFN_DOWN(max_zone_dma_phys());
max_zone_pfns[ZONE_NORMAL] = max;
free_area_init_nodes(max_zone_pfns);
}
#else
static void __init zone_sizes_init(unsigned long min, unsigned long max)
{
struct memblock_region *reg;
unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
unsigned long max_dma = min;
memset(zone_size, 0, sizeof(zone_size));
/* 4GB maximum for 32-bit only capable devices */
#ifdef CONFIG_ZONE_DMA
max_dma = PFN_DOWN(arm64_dma_phys_limit);
zone_size[ZONE_DMA] = max_dma - min;
#endif
zone_size[ZONE_NORMAL] = max - max_dma;
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)
continue;
#ifdef CONFIG_ZONE_DMA
if (start < max_dma) {
unsigned long dma_end = min(end, max_dma);
zhole_size[ZONE_DMA] -= dma_end - start;
}
#endif
if (end > max_dma) {
unsigned long normal_end = min(end, max);
unsigned long normal_start = max(start, max_dma);
zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
}
}
free_area_init_node(0, zone_size, min, zhole_size);
}
#endif /* CONFIG_NUMA */
#ifdef CONFIG_HAVE_ARCH_PFN_VALID
int pfn_valid(unsigned long pfn)
{
phys_addr_t addr = pfn << PAGE_SHIFT;
if ((addr >> PAGE_SHIFT) != pfn)
return 0;
return memblock_is_map_memory(addr);
}
EXPORT_SYMBOL(pfn_valid);
#endif
#ifndef CONFIG_SPARSEMEM
static void __init arm64_memory_present(void)
{
}
#else
static void __init arm64_memory_present(void)
{
struct memblock_region *reg;
for_each_memblock(memory, reg) {
int nid = memblock_get_region_node(reg);
memory_present(nid, memblock_region_memory_base_pfn(reg),
memblock_region_memory_end_pfn(reg));
}
}
#endif
static phys_addr_t memory_limit = (phys_addr_t)ULLONG_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)
{
const s64 linear_region_size = -(s64)PAGE_OFFSET;
/*
* Ensure that the linear region takes up exactly half of the kernel
* virtual address space. This way, we can distinguish a linear address
* from a kernel/module/vmalloc address by testing a single bit.
*/
BUILD_BUG_ON(linear_region_size != BIT(VA_BITS - 1));
/*
* Select a suitable value for the base of physical memory.
*/
memstart_addr = round_down(memblock_start_of_DRAM(),
ARM64_MEMSTART_ALIGN);
/*
* 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_t)ULLONG_MAX) {
memblock_mem_limit_remove_map(memory_limit);
memblock_add(__pa_symbol(_text), (u64)(_end - _text));
}
if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && initrd_start) {
/*
* 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 = initrd_start & PAGE_MASK;
u64 size = PAGE_ALIGN(initrd_end) - 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")) {
initrd_start = 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);
#ifdef CONFIG_BLK_DEV_INITRD
if (initrd_start) {
memblock_reserve(initrd_start, initrd_end - initrd_start);
/* the generic initrd code expects virtual addresses */
initrd_start = __phys_to_virt(initrd_start);
initrd_end = __phys_to_virt(initrd_end);
}
#endif
early_init_fdt_scan_reserved_mem();
/* 4GB maximum for 32-bit only capable devices */
if (IS_ENABLED(CONFIG_ZONE_DMA))
arm64_dma_phys_limit = max_zone_dma_phys();
else
arm64_dma_phys_limit = PHYS_MASK + 1;
high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
dma_contiguous_reserve(arm64_dma_phys_limit);
memblock_allow_resize();
}
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;
arm64_numa_init();
/*
* Sparsemem tries to allocate bootmem in memory_present(), so must be
* done after the fixed reservations.
*/
arm64_memory_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)
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(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)
{
#ifdef CONFIG_SWIOTLB
if (swiotlb_force == SWIOTLB_FORCE ||
max_pfn > (arm64_dma_phys_limit >> PAGE_SHIFT))
swiotlb_init(1);
else
swiotlb_force = SWIOTLB_NO_FORCE;
#endif
set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
#ifndef CONFIG_SPARSEMEM_VMEMMAP
free_unused_memmap();
#endif
/* this will put all unused low memory onto the freelists */
free_all_bootmem();
mem_init_print_info(NULL);
#define MLK(b, t) b, t, ((t) - (b)) >> 10
#define MLM(b, t) b, t, ((t) - (b)) >> 20
#define MLG(b, t) b, t, ((t) - (b)) >> 30
#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
pr_notice("Virtual kernel memory layout:\n");
#ifdef CONFIG_KASAN
pr_notice(" kasan : 0x%16lx - 0x%16lx (%6ld GB)\n",
MLG(KASAN_SHADOW_START, KASAN_SHADOW_END));
#endif
pr_notice(" modules : 0x%16lx - 0x%16lx (%6ld MB)\n",
MLM(MODULES_VADDR, MODULES_END));
pr_notice(" vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n",
MLG(VMALLOC_START, VMALLOC_END));
pr_notice(" .text : 0x%p" " - 0x%p" " (%6ld KB)\n",
MLK_ROUNDUP(_text, _etext));
pr_notice(" .rodata : 0x%p" " - 0x%p" " (%6ld KB)\n",
MLK_ROUNDUP(__start_rodata, __init_begin));
pr_notice(" .init : 0x%p" " - 0x%p" " (%6ld KB)\n",
MLK_ROUNDUP(__init_begin, __init_end));
pr_notice(" .data : 0x%p" " - 0x%p" " (%6ld KB)\n",
MLK_ROUNDUP(_sdata, _edata));
pr_notice(" .bss : 0x%p" " - 0x%p" " (%6ld KB)\n",
MLK_ROUNDUP(__bss_start, __bss_stop));
pr_notice(" fixed : 0x%16lx - 0x%16lx (%6ld KB)\n",
MLK(FIXADDR_START, FIXADDR_TOP));
pr_notice(" PCI I/O : 0x%16lx - 0x%16lx (%6ld MB)\n",
MLM(PCI_IO_START, PCI_IO_END));
#ifdef CONFIG_SPARSEMEM_VMEMMAP
pr_notice(" vmemmap : 0x%16lx - 0x%16lx (%6ld GB maximum)\n",
MLG(VMEMMAP_START, VMEMMAP_START + VMEMMAP_SIZE));
pr_notice(" 0x%16lx - 0x%16lx (%6ld MB actual)\n",
MLM((unsigned long)phys_to_page(memblock_start_of_DRAM()),
(unsigned long)virt_to_page(high_memory)));
#endif
pr_notice(" memory : 0x%16lx - 0x%16lx (%6ld MB)\n",
MLM(__phys_to_virt(memblock_start_of_DRAM()),
(unsigned long)high_memory));
#undef MLK
#undef MLM
#undef MLK_ROUNDUP
/*
* Check boundaries twice: Some fundamental inconsistencies can be
* detected at build time already.
*/
#ifdef CONFIG_COMPAT
BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64);
#endif
#ifdef CONFIG_SPARSEMEM_VMEMMAP
/*
* Make sure we chose the upper bound of sizeof(struct page)
* correctly when sizing the VMEMMAP array.
*/
BUILD_BUG_ON(sizeof(struct page) > (1 << STRUCT_PAGE_MAX_SHIFT));
#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),
0, "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));
}
#ifdef CONFIG_BLK_DEV_INITRD
static int keep_initrd __initdata;
void __init free_initrd_mem(unsigned long start, unsigned long end)
{
if (!keep_initrd)
free_reserved_area((void *)start, (void *)end, 0, "initrd");
}
static int __init keepinitrd_setup(char *__unused)
{
keep_initrd = 1;
return 1;
}
__setup("keepinitrd", keepinitrd_setup);
#endif
/*
* 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_t)ULLONG_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);
#ifdef CONFIG_MEMORY_HOTPLUG
int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
{
pg_data_t *pgdat;
struct zone *zone;
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
unsigned long end_pfn = start_pfn + nr_pages;
unsigned long max_sparsemem_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
int ret;
if (end_pfn > max_sparsemem_pfn) {
pr_err("end_pfn too big");
return -1;
}
hotplug_paging(start, size);
/*
* Mark the first page in the range as unusable. This is needed
* because __add_section (within __add_pages) wants pfn_valid
* of it to be false, and in arm64 pfn falid is implemented by
* just checking at the nomap flag for existing blocks.
*
* A small trick here is that __add_section() requires only
* phys_start_pfn (that is the first pfn of a section) to be
* invalid. Regardless of whether it was assumed (by the function
* author) that all pfns within a section are either all valid
* or all invalid, it allows to avoid looping twice (once here,
* second when memblock_clear_nomap() is called) through all
* pfns of the section and modify only one pfn. Thanks to that,
* further, in __add_zone() only this very first pfn is skipped
* and corresponding page is not flagged reserved. Therefore it
* is enough to correct this setup only for it.
*
* When arch_add_memory() returns the walk_memory_range() function
* is called and passed with online_memory_block() callback,
* which execution finally reaches the memory_block_action()
* function, where also only the first pfn of a memory block is
* checked to be reserved. Above, it was first pfn of a section,
* here it is a block but
* (drivers/base/memory.c):
* sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
* (include/linux/memory.h):
* #define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
* so we can consider block and section equivalently
*/
memblock_mark_nomap(start, 1<<PAGE_SHIFT);
pgdat = NODE_DATA(nid);
zone = pgdat->node_zones +
zone_for_memory(nid, start, size, ZONE_NORMAL, for_device);
ret = __add_pages(nid, zone, start_pfn, nr_pages);
/*
* Make the pages usable after they have been added.
* This will make pfn_valid return true
*/
memblock_clear_nomap(start, 1<<PAGE_SHIFT);
/*
* This is a hack to avoid having to mix arch specific code
* into arch independent code. SetPageReserved is supposed
* to be called by __add_zone (within __add_section, within
* __add_pages). However, when it is called there, it assumes that
* pfn_valid returns true. For the way pfn_valid is implemented
* in arm64 (a check on the nomap flag), the only way to make
* this evaluate true inside __add_zone is to clear the nomap
* flags of blocks in architecture independent code.
*
* To avoid this, we set the Reserved flag here after we cleared
* the nomap flag in the line above.
*/
SetPageReserved(pfn_to_page(start_pfn));
if (ret)
pr_warn("%s: Problem encountered in __add_pages() ret=%d\n",
__func__, ret);
return ret;
}
#ifdef CONFIG_MEMORY_HOTREMOVE
static void kernel_physical_mapping_remove(unsigned long start,
unsigned long end)
{
start = (unsigned long)__va(start);
end = (unsigned long)__va(end);
remove_pagetable(start, end, true);
}
int arch_remove_memory(u64 start, u64 size)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
struct page *page = pfn_to_page(start_pfn);
struct zone *zone;
int ret = 0;
zone = page_zone(page);
ret = __remove_pages(zone, start_pfn, nr_pages);
WARN_ON_ONCE(ret);
kernel_physical_mapping_remove(start, start + size);
return ret;
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
#endif /* CONFIG_MEMORY_HOTPLUG */
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