linux/mm/sparse.c

790 lines
20 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* sparse memory mappings.
*/
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/mmzone.h>
#include <linux/bootmem.h>
#include <linux/compiler.h>
#include <linux/highmem.h>
#include <linux/export.h>
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include "internal.h"
#include <asm/dma.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
/*
* Permanent SPARSEMEM data:
*
* 1) mem_section - memory sections, mem_map's for valid memory
*/
#ifdef CONFIG_SPARSEMEM_EXTREME
struct mem_section **mem_section;
#else
struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
____cacheline_internodealigned_in_smp;
#endif
EXPORT_SYMBOL(mem_section);
#ifdef NODE_NOT_IN_PAGE_FLAGS
/*
* If we did not store the node number in the page then we have to
* do a lookup in the section_to_node_table in order to find which
* node the page belongs to.
*/
#if MAX_NUMNODES <= 256
static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
#else
static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
#endif
int page_to_nid(const struct page *page)
{
return section_to_node_table[page_to_section(page)];
}
EXPORT_SYMBOL(page_to_nid);
static void set_section_nid(unsigned long section_nr, int nid)
{
section_to_node_table[section_nr] = nid;
}
#else /* !NODE_NOT_IN_PAGE_FLAGS */
static inline void set_section_nid(unsigned long section_nr, int nid)
{
}
#endif
#ifdef CONFIG_SPARSEMEM_EXTREME
static noinline struct mem_section __ref *sparse_index_alloc(int nid)
{
struct mem_section *section = NULL;
unsigned long array_size = SECTIONS_PER_ROOT *
sizeof(struct mem_section);
if (slab_is_available())
section = kzalloc_node(array_size, GFP_KERNEL, nid);
else
section = memblock_virt_alloc_node(array_size, nid);
return section;
}
static int __meminit sparse_index_init(unsigned long section_nr, int nid)
{
unsigned long root = SECTION_NR_TO_ROOT(section_nr);
struct mem_section *section;
if (mem_section[root])
return -EEXIST;
section = sparse_index_alloc(nid);
if (!section)
return -ENOMEM;
mem_section[root] = section;
return 0;
}
#else /* !SPARSEMEM_EXTREME */
static inline int sparse_index_init(unsigned long section_nr, int nid)
{
return 0;
}
#endif
#ifdef CONFIG_SPARSEMEM_EXTREME
int __section_nr(struct mem_section* ms)
{
unsigned long root_nr;
struct mem_section *root = NULL;
for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
if (!root)
continue;
if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
break;
}
VM_BUG_ON(!root);
return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
}
#else
int __section_nr(struct mem_section* ms)
{
return (int)(ms - mem_section[0]);
}
#endif
/*
* During early boot, before section_mem_map is used for an actual
* mem_map, we use section_mem_map to store the section's NUMA
* node. This keeps us from having to use another data structure. The
* node information is cleared just before we store the real mem_map.
*/
static inline unsigned long sparse_encode_early_nid(int nid)
{
return (nid << SECTION_NID_SHIFT);
}
static inline int sparse_early_nid(struct mem_section *section)
{
return (section->section_mem_map >> SECTION_NID_SHIFT);
}
/* Validate the physical addressing limitations of the model */
void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn,
unsigned long *end_pfn)
{
unsigned long max_sparsemem_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
/*
* Sanity checks - do not allow an architecture to pass
* in larger pfns than the maximum scope of sparsemem:
*/
if (*start_pfn > max_sparsemem_pfn) {
mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
"Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
*start_pfn, *end_pfn, max_sparsemem_pfn);
WARN_ON_ONCE(1);
*start_pfn = max_sparsemem_pfn;
*end_pfn = max_sparsemem_pfn;
} else if (*end_pfn > max_sparsemem_pfn) {
mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
"End of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
*start_pfn, *end_pfn, max_sparsemem_pfn);
WARN_ON_ONCE(1);
*end_pfn = max_sparsemem_pfn;
}
}
/*
* There are a number of times that we loop over NR_MEM_SECTIONS,
* looking for section_present() on each. But, when we have very
* large physical address spaces, NR_MEM_SECTIONS can also be
* very large which makes the loops quite long.
*
* Keeping track of this gives us an easy way to break out of
* those loops early.
*/
int __highest_present_section_nr;
static void section_mark_present(struct mem_section *ms)
{
int section_nr = __section_nr(ms);
if (section_nr > __highest_present_section_nr)
__highest_present_section_nr = section_nr;
ms->section_mem_map |= SECTION_MARKED_PRESENT;
}
static inline int next_present_section_nr(int section_nr)
{
do {
section_nr++;
if (present_section_nr(section_nr))
return section_nr;
} while ((section_nr <= __highest_present_section_nr));
return -1;
}
#define for_each_present_section_nr(start, section_nr) \
for (section_nr = next_present_section_nr(start-1); \
((section_nr >= 0) && \
(section_nr <= __highest_present_section_nr)); \
section_nr = next_present_section_nr(section_nr))
static inline unsigned long first_present_section_nr(void)
{
return next_present_section_nr(-1);
}
/* Record a memory area against a node. */
void __init memory_present(int nid, unsigned long start, unsigned long end)
{
unsigned long pfn;
#ifdef CONFIG_SPARSEMEM_EXTREME
if (unlikely(!mem_section)) {
unsigned long size, align;
size = sizeof(struct mem_section*) * NR_SECTION_ROOTS;
align = 1 << (INTERNODE_CACHE_SHIFT);
mem_section = memblock_virt_alloc(size, align);
}
#endif
start &= PAGE_SECTION_MASK;
mminit_validate_memmodel_limits(&start, &end);
for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
unsigned long section = pfn_to_section_nr(pfn);
struct mem_section *ms;
sparse_index_init(section, nid);
set_section_nid(section, nid);
ms = __nr_to_section(section);
if (!ms->section_mem_map) {
ms->section_mem_map = sparse_encode_early_nid(nid) |
SECTION_IS_ONLINE;
section_mark_present(ms);
}
}
}
/*
* Subtle, we encode the real pfn into the mem_map such that
* the identity pfn - section_mem_map will return the actual
* physical page frame number.
*/
static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
{
unsigned long coded_mem_map =
(unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
BUILD_BUG_ON(SECTION_MAP_LAST_BIT > (1UL<<PFN_SECTION_SHIFT));
BUG_ON(coded_mem_map & ~SECTION_MAP_MASK);
return coded_mem_map;
}
/*
* Decode mem_map from the coded memmap
*/
struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
{
/* mask off the extra low bits of information */
coded_mem_map &= SECTION_MAP_MASK;
return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
}
static void __meminit sparse_init_one_section(struct mem_section *ms,
unsigned long pnum, struct page *mem_map,
unsigned long *pageblock_bitmap)
{
ms->section_mem_map &= ~SECTION_MAP_MASK;
ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
SECTION_HAS_MEM_MAP;
ms->pageblock_flags = pageblock_bitmap;
}
unsigned long usemap_size(void)
{
return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long);
}
#ifdef CONFIG_MEMORY_HOTPLUG
static unsigned long *__kmalloc_section_usemap(void)
{
return kmalloc(usemap_size(), GFP_KERNEL);
}
#endif /* CONFIG_MEMORY_HOTPLUG */
#ifdef CONFIG_MEMORY_HOTREMOVE
static unsigned long * __init
sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
unsigned long size)
{
unsigned long goal, limit;
unsigned long *p;
int nid;
/*
* A page may contain usemaps for other sections preventing the
* page being freed and making a section unremovable while
* other sections referencing the usemap remain active. Similarly,
* a pgdat can prevent a section being removed. If section A
* contains a pgdat and section B contains the usemap, both
* sections become inter-dependent. This allocates usemaps
* from the same section as the pgdat where possible to avoid
* this problem.
*/
goal = __pa(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT);
limit = goal + (1UL << PA_SECTION_SHIFT);
nid = early_pfn_to_nid(goal >> PAGE_SHIFT);
again:
p = memblock_virt_alloc_try_nid_nopanic(size,
SMP_CACHE_BYTES, goal, limit,
nid);
if (!p && limit) {
limit = 0;
goto again;
}
return p;
}
static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
{
unsigned long usemap_snr, pgdat_snr;
static unsigned long old_usemap_snr;
static unsigned long old_pgdat_snr;
struct pglist_data *pgdat = NODE_DATA(nid);
int usemap_nid;
/* First call */
if (!old_usemap_snr) {
old_usemap_snr = NR_MEM_SECTIONS;
old_pgdat_snr = NR_MEM_SECTIONS;
}
usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT);
pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
if (usemap_snr == pgdat_snr)
return;
if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
/* skip redundant message */
return;
old_usemap_snr = usemap_snr;
old_pgdat_snr = pgdat_snr;
usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
if (usemap_nid != nid) {
pr_info("node %d must be removed before remove section %ld\n",
nid, usemap_snr);
return;
}
/*
* There is a circular dependency.
* Some platforms allow un-removable section because they will just
* gather other removable sections for dynamic partitioning.
* Just notify un-removable section's number here.
*/
pr_info("Section %ld and %ld (node %d) have a circular dependency on usemap and pgdat allocations\n",
usemap_snr, pgdat_snr, nid);
}
#else
static unsigned long * __init
sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
unsigned long size)
{
return memblock_virt_alloc_node_nopanic(size, pgdat->node_id);
}
static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
{
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
#ifdef CONFIG_SPARSEMEM_VMEMMAP
static unsigned long __init section_map_size(void)
{
return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE);
}
#else
static unsigned long __init section_map_size(void)
{
return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
}
struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid,
struct vmem_altmap *altmap)
{
unsigned long size = section_map_size();
struct page *map = sparse_buffer_alloc(size);
if (map)
return map;
map = memblock_virt_alloc_try_nid(size,
PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
BOOTMEM_ALLOC_ACCESSIBLE, nid);
return map;
}
#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
static void *sparsemap_buf __meminitdata;
static void *sparsemap_buf_end __meminitdata;
static void __init sparse_buffer_init(unsigned long size, int nid)
{
WARN_ON(sparsemap_buf); /* forgot to call sparse_buffer_fini()? */
sparsemap_buf =
memblock_virt_alloc_try_nid_raw(size, PAGE_SIZE,
__pa(MAX_DMA_ADDRESS),
BOOTMEM_ALLOC_ACCESSIBLE, nid);
sparsemap_buf_end = sparsemap_buf + size;
}
static void __init sparse_buffer_fini(void)
{
unsigned long size = sparsemap_buf_end - sparsemap_buf;
if (sparsemap_buf && size > 0)
memblock_free_early(__pa(sparsemap_buf), size);
sparsemap_buf = NULL;
}
void * __meminit sparse_buffer_alloc(unsigned long size)
{
void *ptr = NULL;
if (sparsemap_buf) {
ptr = PTR_ALIGN(sparsemap_buf, size);
if (ptr + size > sparsemap_buf_end)
ptr = NULL;
else
sparsemap_buf = ptr + size;
}
return ptr;
}
void __weak __meminit vmemmap_populate_print_last(void)
{
}
/*
* Initialize sparse on a specific node. The node spans [pnum_begin, pnum_end)
* And number of present sections in this node is map_count.
*/
static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
unsigned long pnum_end,
unsigned long map_count)
{
unsigned long pnum, usemap_longs, *usemap;
struct page *map;
usemap_longs = BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS);
usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid),
usemap_size() *
map_count);
if (!usemap) {
pr_err("%s: node[%d] usemap allocation failed", __func__, nid);
goto failed;
}
sparse_buffer_init(map_count * section_map_size(), nid);
for_each_present_section_nr(pnum_begin, pnum) {
if (pnum >= pnum_end)
break;
map = sparse_mem_map_populate(pnum, nid, NULL);
if (!map) {
pr_err("%s: node[%d] memory map backing failed. Some memory will not be available.",
__func__, nid);
pnum_begin = pnum;
goto failed;
}
check_usemap_section_nr(nid, usemap);
sparse_init_one_section(__nr_to_section(pnum), pnum, map, usemap);
usemap += usemap_longs;
}
sparse_buffer_fini();
return;
failed:
/* We failed to allocate, mark all the following pnums as not present */
for_each_present_section_nr(pnum_begin, pnum) {
struct mem_section *ms;
if (pnum >= pnum_end)
break;
ms = __nr_to_section(pnum);
ms->section_mem_map = 0;
}
}
/*
* Allocate the accumulated non-linear sections, allocate a mem_map
* for each and record the physical to section mapping.
*/
void __init sparse_init(void)
{
unsigned long pnum_begin = first_present_section_nr();
int nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
unsigned long pnum_end, map_count = 1;
/* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
set_pageblock_order();
for_each_present_section_nr(pnum_begin + 1, pnum_end) {
int nid = sparse_early_nid(__nr_to_section(pnum_end));
if (nid == nid_begin) {
map_count++;
continue;
}
/* Init node with sections in range [pnum_begin, pnum_end) */
sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
nid_begin = nid;
pnum_begin = pnum_end;
map_count = 1;
}
/* cover the last node */
sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
vmemmap_populate_print_last();
}
#ifdef CONFIG_MEMORY_HOTPLUG
/* Mark all memory sections within the pfn range as online */
void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
{
unsigned long pfn;
for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
unsigned long section_nr = pfn_to_section_nr(pfn);
struct mem_section *ms;
/* onlining code should never touch invalid ranges */
if (WARN_ON(!valid_section_nr(section_nr)))
continue;
ms = __nr_to_section(section_nr);
ms->section_mem_map |= SECTION_IS_ONLINE;
}
}
#ifdef CONFIG_MEMORY_HOTREMOVE
/* Mark all memory sections within the pfn range as online */
void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
{
unsigned long pfn;
for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
unsigned long section_nr = pfn_to_section_nr(pfn);
struct mem_section *ms;
/*
* TODO this needs some double checking. Offlining code makes
* sure to check pfn_valid but those checks might be just bogus
*/
if (WARN_ON(!valid_section_nr(section_nr)))
continue;
ms = __nr_to_section(section_nr);
ms->section_mem_map &= ~SECTION_IS_ONLINE;
}
}
#endif
#ifdef CONFIG_SPARSEMEM_VMEMMAP
static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
struct vmem_altmap *altmap)
{
/* This will make the necessary allocations eventually. */
return sparse_mem_map_populate(pnum, nid, altmap);
}
static void __kfree_section_memmap(struct page *memmap,
struct vmem_altmap *altmap)
{
unsigned long start = (unsigned long)memmap;
unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
vmemmap_free(start, end, altmap);
}
#ifdef CONFIG_MEMORY_HOTREMOVE
static void free_map_bootmem(struct page *memmap)
{
unsigned long start = (unsigned long)memmap;
unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
vmemmap_free(start, end, NULL);
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
#else
static struct page *__kmalloc_section_memmap(void)
{
struct page *page, *ret;
unsigned long memmap_size = sizeof(struct page) * PAGES_PER_SECTION;
page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
if (page)
goto got_map_page;
ret = vmalloc(memmap_size);
if (ret)
goto got_map_ptr;
return NULL;
got_map_page:
ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
got_map_ptr:
return ret;
}
static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
struct vmem_altmap *altmap)
{
return __kmalloc_section_memmap();
}
static void __kfree_section_memmap(struct page *memmap,
struct vmem_altmap *altmap)
{
if (is_vmalloc_addr(memmap))
vfree(memmap);
else
free_pages((unsigned long)memmap,
get_order(sizeof(struct page) * PAGES_PER_SECTION));
}
#ifdef CONFIG_MEMORY_HOTREMOVE
static void free_map_bootmem(struct page *memmap)
{
unsigned long maps_section_nr, removing_section_nr, i;
unsigned long magic, nr_pages;
struct page *page = virt_to_page(memmap);
nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
>> PAGE_SHIFT;
for (i = 0; i < nr_pages; i++, page++) {
magic = (unsigned long) page->freelist;
BUG_ON(magic == NODE_INFO);
maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
removing_section_nr = page_private(page);
/*
* When this function is called, the removing section is
* logical offlined state. This means all pages are isolated
* from page allocator. If removing section's memmap is placed
* on the same section, it must not be freed.
* If it is freed, page allocator may allocate it which will
* be removed physically soon.
*/
if (maps_section_nr != removing_section_nr)
put_page_bootmem(page);
}
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
/*
* returns the number of sections whose mem_maps were properly
* set. If this is <=0, then that means that the passed-in
* map was not consumed and must be freed.
*/
int __meminit sparse_add_one_section(struct pglist_data *pgdat,
unsigned long start_pfn, struct vmem_altmap *altmap)
{
unsigned long section_nr = pfn_to_section_nr(start_pfn);
struct mem_section *ms;
struct page *memmap;
unsigned long *usemap;
unsigned long flags;
int ret;
/*
* no locking for this, because it does its own
* plus, it does a kmalloc
*/
ret = sparse_index_init(section_nr, pgdat->node_id);
if (ret < 0 && ret != -EEXIST)
return ret;
ret = 0;
memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, altmap);
if (!memmap)
return -ENOMEM;
usemap = __kmalloc_section_usemap();
if (!usemap) {
__kfree_section_memmap(memmap, altmap);
return -ENOMEM;
}
pgdat_resize_lock(pgdat, &flags);
ms = __pfn_to_section(start_pfn);
if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
ret = -EEXIST;
goto out;
}
/*
* Poison uninitialized struct pages in order to catch invalid flags
* combinations.
*/
page_init_poison(memmap, sizeof(struct page) * PAGES_PER_SECTION);
section_mark_present(ms);
sparse_init_one_section(ms, section_nr, memmap, usemap);
out:
pgdat_resize_unlock(pgdat, &flags);
if (ret < 0) {
kfree(usemap);
__kfree_section_memmap(memmap, altmap);
}
return ret;
}
#ifdef CONFIG_MEMORY_HOTREMOVE
#ifdef CONFIG_MEMORY_FAILURE
static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
{
int i;
if (!memmap)
return;
for (i = 0; i < nr_pages; i++) {
if (PageHWPoison(&memmap[i])) {
atomic_long_sub(1, &num_poisoned_pages);
ClearPageHWPoison(&memmap[i]);
}
}
}
#else
static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
{
}
#endif
static void free_section_usemap(struct page *memmap, unsigned long *usemap,
struct vmem_altmap *altmap)
{
struct page *usemap_page;
if (!usemap)
return;
usemap_page = virt_to_page(usemap);
/*
* Check to see if allocation came from hot-plug-add
*/
if (PageSlab(usemap_page) || PageCompound(usemap_page)) {
kfree(usemap);
if (memmap)
__kfree_section_memmap(memmap, altmap);
return;
}
/*
* The usemap came from bootmem. This is packed with other usemaps
* on the section which has pgdat at boot time. Just keep it as is now.
*/
if (memmap)
free_map_bootmem(memmap);
}
void sparse_remove_one_section(struct zone *zone, struct mem_section *ms,
unsigned long map_offset, struct vmem_altmap *altmap)
{
struct page *memmap = NULL;
unsigned long *usemap = NULL, flags;
struct pglist_data *pgdat = zone->zone_pgdat;
pgdat_resize_lock(pgdat, &flags);
if (ms->section_mem_map) {
usemap = ms->pageblock_flags;
memmap = sparse_decode_mem_map(ms->section_mem_map,
__section_nr(ms));
ms->section_mem_map = 0;
ms->pageblock_flags = NULL;
}
pgdat_resize_unlock(pgdat, &flags);
clear_hwpoisoned_pages(memmap + map_offset,
PAGES_PER_SECTION - map_offset);
free_section_usemap(memmap, usemap, altmap);
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
#endif /* CONFIG_MEMORY_HOTPLUG */