| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| David Hildenbrand | 2297 | 27.83% | 68 | 16.75% |
| Michal Hocko | 576 | 6.98% | 28 | 6.90% |
| Vishal Verma | 448 | 5.43% | 4 | 0.99% |
| Dan J Williams | 396 | 4.80% | 15 | 3.69% |
| Kamezawa Hiroyuki | 392 | 4.75% | 9 | 2.22% |
| Oscar Salvador | 386 | 4.68% | 13 | 3.20% |
| Yasuaki Ishimatsu | 355 | 4.30% | 4 | 0.99% |
| Aneesh Kumar K.V | 351 | 4.25% | 4 | 0.99% |
| Lai Jiangshan | 296 | 3.59% | 4 | 0.99% |
| Anshuman Khandual | 262 | 3.17% | 5 | 1.23% |
| Yasunori Goto | 253 | 3.06% | 12 | 2.96% |
| Dave Hansen | 133 | 1.61% | 8 | 1.97% |
| Wen Congyang | 115 | 1.39% | 10 | 2.46% |
| Tang Chen | 110 | 1.33% | 6 | 1.48% |
| Daniel Kiper | 108 | 1.31% | 1 | 0.25% |
| Vitaly Kuznetsov | 75 | 0.91% | 4 | 0.99% |
| Naoya Horiguchi | 73 | 0.88% | 2 | 0.49% |
| JoonSoo Kim | 68 | 0.82% | 2 | 0.49% |
| David Vrabel | 67 | 0.81% | 1 | 0.25% |
| Pavel Tatashin | 59 | 0.71% | 2 | 0.49% |
| Toshi Kani | 58 | 0.70% | 6 | 1.48% |
| Vladimir Davydov | 58 | 0.70% | 1 | 0.25% |
| Song Muchun | 56 | 0.68% | 4 | 0.99% |
| Matt Tolentino | 54 | 0.65% | 1 | 0.25% |
| Minskey Guo | 52 | 0.63% | 1 | 0.25% |
| Ben Widawsky | 52 | 0.63% | 1 | 0.25% |
| Sumanth Korikkar | 51 | 0.62% | 4 | 0.99% |
| David Rientjes | 51 | 0.62% | 5 | 1.23% |
| Yisheng Xie | 36 | 0.44% | 1 | 0.25% |
| Motohiro Kosaki | 35 | 0.42% | 5 | 1.23% |
| Xishi Qiu | 34 | 0.41% | 6 | 1.48% |
| Chen Yucong | 33 | 0.40% | 1 | 0.25% |
| Matthew Wilcox | 32 | 0.39% | 3 | 0.74% |
| Vlastimil Babka | 32 | 0.39% | 3 | 0.74% |
| Arun K S | 31 | 0.38% | 1 | 0.25% |
| Liam Mark | 31 | 0.38% | 1 | 0.25% |
| Badari Pulavarty | 29 | 0.35% | 3 | 0.74% |
| Björn Helgaas | 28 | 0.34% | 1 | 0.25% |
| Andrew Morton | 26 | 0.31% | 8 | 1.97% |
| Qian Cai | 25 | 0.30% | 1 | 0.25% |
| Gerald Schaefer | 24 | 0.29% | 2 | 0.49% |
| Randy Dunlap | 23 | 0.28% | 2 | 0.49% |
| Jiang Liu | 23 | 0.28% | 5 | 1.23% |
| Heiko Carstens | 23 | 0.28% | 3 | 0.74% |
| Linus Torvalds (pre-git) | 23 | 0.28% | 8 | 1.97% |
| Thomas Gleixner | 23 | 0.28% | 3 | 0.74% |
| Keith Mannthey | 22 | 0.27% | 1 | 0.25% |
| Nathan Fontenot | 22 | 0.27% | 6 | 1.48% |
| Miaohe Lin | 21 | 0.25% | 7 | 1.72% |
| Logan Gunthorpe | 20 | 0.24% | 2 | 0.49% |
| Juergen Gross | 20 | 0.24% | 1 | 0.25% |
| Kirill A. Shutemov | 19 | 0.23% | 3 | 0.74% |
| Rafael J. Wysocki | 18 | 0.22% | 3 | 0.74% |
| Christoph Hellwig | 16 | 0.19% | 7 | 1.72% |
| Andi Kleen | 15 | 0.18% | 3 | 0.74% |
| Sidhartha Kumar | 14 | 0.17% | 3 | 0.74% |
| Cody P Schafer | 14 | 0.17% | 2 | 0.49% |
| Fengguang Wu | 13 | 0.16% | 2 | 0.49% |
| Reza Arbab | 12 | 0.15% | 1 | 0.25% |
| MinChan Kim | 12 | 0.15% | 3 | 0.74% |
| Kefeng Wang | 11 | 0.13% | 4 | 0.99% |
| Mel Gorman | 11 | 0.13% | 6 | 1.48% |
| Christoph Lameter | 11 | 0.13% | 2 | 0.49% |
| Baolin Wang | 11 | 0.13% | 3 | 0.74% |
| Wei Yang | 10 | 0.12% | 2 | 0.49% |
| Baoquan He | 10 | 0.12% | 4 | 0.99% |
| Jérôme Glisse | 9 | 0.11% | 1 | 0.25% |
| Anastasia Belova | 9 | 0.11% | 1 | 0.25% |
| Linus Torvalds | 9 | 0.11% | 3 | 0.74% |
| Gary Hade | 9 | 0.11% | 1 | 0.25% |
| Alastair D'Silva | 8 | 0.10% | 1 | 0.25% |
| Michal Nazarewicz | 8 | 0.10% | 1 | 0.25% |
| Hugh Dickins | 7 | 0.08% | 2 | 0.49% |
| Li Zhong | 7 | 0.08% | 2 | 0.49% |
| Greg Kroah-Hartman | 6 | 0.07% | 1 | 0.25% |
| Konstantin Khlebnikov | 6 | 0.07% | 1 | 0.25% |
| Paul Mundt | 6 | 0.07% | 1 | 0.25% |
| SeongJae Park | 5 | 0.06% | 1 | 0.25% |
| Zhang Zhen | 5 | 0.06% | 1 | 0.25% |
| Andy Whitcroft | 5 | 0.06% | 2 | 0.49% |
| Nathan Zimmer | 5 | 0.06% | 1 | 0.25% |
| Nicholas Piggin | 4 | 0.05% | 1 | 0.25% |
| Joao Martins | 4 | 0.05% | 1 | 0.25% |
| Laurent Dufour | 4 | 0.05% | 3 | 0.74% |
| Zi Yan | 4 | 0.05% | 2 | 0.49% |
| Catalin Marinas | 4 | 0.05% | 1 | 0.25% |
| Jia He | 4 | 0.05% | 1 | 0.25% |
| Ingo Molnar | 3 | 0.04% | 1 | 0.25% |
| Namhyung Kim | 3 | 0.04% | 1 | 0.25% |
| Brent Casavant | 3 | 0.04% | 1 | 0.25% |
| Chandra Seetharaman | 3 | 0.04% | 1 | 0.25% |
| Bernhard Walle | 3 | 0.04% | 1 | 0.25% |
| Haicheng Li | 3 | 0.04% | 1 | 0.25% |
| Zhu Guihua | 3 | 0.04% | 1 | 0.25% |
| Rusty Russell | 3 | 0.04% | 1 | 0.25% |
| Jakub Kiciński | 3 | 0.04% | 1 | 0.25% |
| Adrian Bunk | 3 | 0.04% | 1 | 0.25% |
| Bob Liu | 3 | 0.04% | 1 | 0.25% |
| liusongtang | 3 | 0.04% | 1 | 0.25% |
| Al Viro | 3 | 0.04% | 1 | 0.25% |
| Paul Jackson | 2 | 0.02% | 1 | 0.25% |
| Yang Shi | 2 | 0.02% | 1 | 0.25% |
| Zhen Lei | 2 | 0.02% | 1 | 0.25% |
| Tang Yizhou | 2 | 0.02% | 1 | 0.25% |
| Rick Wertenbroek | 2 | 0.02% | 1 | 0.25% |
| Jan Beulich | 2 | 0.02% | 1 | 0.25% |
| Huang Ying | 1 | 0.01% | 1 | 0.25% |
| Paul Gortmaker | 1 | 0.01% | 1 | 0.25% |
| Qi Zheng | 1 | 0.01% | 1 | 0.25% |
| Yajun Deng | 1 | 0.01% | 1 | 0.25% |
| Souptick Joarder | 1 | 0.01% | 1 | 0.25% |
| Jonathan Cameron | 1 | 0.01% | 1 | 0.25% |
| Joe Perches | 1 | 0.01% | 1 | 0.25% |
| Mike Kravetz | 1 | 0.01% | 1 | 0.25% |
| Mike Rapoport | 1 | 0.01% | 1 | 0.25% |
| Hidetoshi Seto | 1 | 0.01% | 1 | 0.25% |
| Tejun Heo | 1 | 0.01% | 1 | 0.25% |
| Total | 8255 | 406 |
// SPDX-License-Identifier: GPL-2.0-only /* * linux/mm/memory_hotplug.c * * Copyright (C) */ #include <linux/stddef.h> #include <linux/mm.h> #include <linux/sched/signal.h> #include <linux/swap.h> #include <linux/interrupt.h> #include <linux/pagemap.h> #include <linux/compiler.h> #include <linux/export.h> #include <linux/writeback.h> #include <linux/slab.h> #include <linux/sysctl.h> #include <linux/cpu.h> #include <linux/memory.h> #include <linux/memremap.h> #include <linux/memory_hotplug.h> #include <linux/vmalloc.h> #include <linux/ioport.h> #include <linux/delay.h> #include <linux/migrate.h> #include <linux/page-isolation.h> #include <linux/pfn.h> #include <linux/suspend.h> #include <linux/mm_inline.h> #include <linux/firmware-map.h> #include <linux/stop_machine.h> #include <linux/hugetlb.h> #include <linux/memblock.h> #include <linux/compaction.h> #include <linux/rmap.h> #include <linux/module.h> #include <asm/tlbflush.h> #include "internal.h" #include "shuffle.h" enum { MEMMAP_ON_MEMORY_DISABLE = 0, MEMMAP_ON_MEMORY_ENABLE, MEMMAP_ON_MEMORY_FORCE, }; static int memmap_mode __read_mostly = MEMMAP_ON_MEMORY_DISABLE; static inline unsigned long memory_block_memmap_size(void) { return PHYS_PFN(memory_block_size_bytes()) * sizeof(struct page); } static inline unsigned long memory_block_memmap_on_memory_pages(void) { unsigned long nr_pages = PFN_UP(memory_block_memmap_size()); /* * In "forced" memmap_on_memory mode, we add extra pages to align the * vmemmap size to cover full pageblocks. That way, we can add memory * even if the vmemmap size is not properly aligned, however, we might waste * memory. */ if (memmap_mode == MEMMAP_ON_MEMORY_FORCE) return pageblock_align(nr_pages); return nr_pages; } #ifdef CONFIG_MHP_MEMMAP_ON_MEMORY /* * memory_hotplug.memmap_on_memory parameter */ static int set_memmap_mode(const char *val, const struct kernel_param *kp) { int ret, mode; bool enabled; if (sysfs_streq(val, "force") || sysfs_streq(val, "FORCE")) { mode = MEMMAP_ON_MEMORY_FORCE; } else { ret = kstrtobool(val, &enabled); if (ret < 0) return ret; if (enabled) mode = MEMMAP_ON_MEMORY_ENABLE; else mode = MEMMAP_ON_MEMORY_DISABLE; } *((int *)kp->arg) = mode; if (mode == MEMMAP_ON_MEMORY_FORCE) { unsigned long memmap_pages = memory_block_memmap_on_memory_pages(); pr_info_once("Memory hotplug will waste %ld pages in each memory block\n", memmap_pages - PFN_UP(memory_block_memmap_size())); } return 0; } static int get_memmap_mode(char *buffer, const struct kernel_param *kp) { int mode = *((int *)kp->arg); if (mode == MEMMAP_ON_MEMORY_FORCE) return sprintf(buffer, "force\n"); return sprintf(buffer, "%c\n", mode ? 'Y' : 'N'); } static const struct kernel_param_ops memmap_mode_ops = { .set = set_memmap_mode, .get = get_memmap_mode, }; module_param_cb(memmap_on_memory, &memmap_mode_ops, &memmap_mode, 0444); MODULE_PARM_DESC(memmap_on_memory, "Enable memmap on memory for memory hotplug\n" "With value \"force\" it could result in memory wastage due " "to memmap size limitations (Y/N/force)"); static inline bool mhp_memmap_on_memory(void) { return memmap_mode != MEMMAP_ON_MEMORY_DISABLE; } #else static inline bool mhp_memmap_on_memory(void) { return false; } #endif enum { ONLINE_POLICY_CONTIG_ZONES = 0, ONLINE_POLICY_AUTO_MOVABLE, }; static const char * const online_policy_to_str[] = { [ONLINE_POLICY_CONTIG_ZONES] = "contig-zones", [ONLINE_POLICY_AUTO_MOVABLE] = "auto-movable", }; static int set_online_policy(const char *val, const struct kernel_param *kp) { int ret = sysfs_match_string(online_policy_to_str, val); if (ret < 0) return ret; *((int *)kp->arg) = ret; return 0; } static int get_online_policy(char *buffer, const struct kernel_param *kp) { return sprintf(buffer, "%s\n", online_policy_to_str[*((int *)kp->arg)]); } /* * memory_hotplug.online_policy: configure online behavior when onlining without * specifying a zone (MMOP_ONLINE) * * "contig-zones": keep zone contiguous * "auto-movable": online memory to ZONE_MOVABLE if the configuration * (auto_movable_ratio, auto_movable_numa_aware) allows for it */ static int online_policy __read_mostly = ONLINE_POLICY_CONTIG_ZONES; static const struct kernel_param_ops online_policy_ops = { .set = set_online_policy, .get = get_online_policy, }; module_param_cb(online_policy, &online_policy_ops, &online_policy, 0644); MODULE_PARM_DESC(online_policy, "Set the online policy (\"contig-zones\", \"auto-movable\") " "Default: \"contig-zones\""); /* * memory_hotplug.auto_movable_ratio: specify maximum MOVABLE:KERNEL ratio * * The ratio represent an upper limit and the kernel might decide to not * online some memory to ZONE_MOVABLE -- e.g., because hotplugged KERNEL memory * doesn't allow for more MOVABLE memory. */ static unsigned int auto_movable_ratio __read_mostly = 301; module_param(auto_movable_ratio, uint, 0644); MODULE_PARM_DESC(auto_movable_ratio, "Set the maximum ratio of MOVABLE:KERNEL memory in the system " "in percent for \"auto-movable\" online policy. Default: 301"); /* * memory_hotplug.auto_movable_numa_aware: consider numa node stats */ #ifdef CONFIG_NUMA static bool auto_movable_numa_aware __read_mostly = true; module_param(auto_movable_numa_aware, bool, 0644); MODULE_PARM_DESC(auto_movable_numa_aware, "Consider numa node stats in addition to global stats in " "\"auto-movable\" online policy. Default: true"); #endif /* CONFIG_NUMA */ /* * online_page_callback contains pointer to current page onlining function. * Initially it is generic_online_page(). If it is required it could be * changed by calling set_online_page_callback() for callback registration * and restore_online_page_callback() for generic callback restore. */ static online_page_callback_t online_page_callback = generic_online_page; static DEFINE_MUTEX(online_page_callback_lock); DEFINE_STATIC_PERCPU_RWSEM(mem_hotplug_lock); void get_online_mems(void) { percpu_down_read(&mem_hotplug_lock); } void put_online_mems(void) { percpu_up_read(&mem_hotplug_lock); } bool movable_node_enabled = false; #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE int mhp_default_online_type = MMOP_OFFLINE; #else int mhp_default_online_type = MMOP_ONLINE; #endif static int __init setup_memhp_default_state(char *str) { const int online_type = mhp_online_type_from_str(str); if (online_type >= 0) mhp_default_online_type = online_type; return 1; } __setup("memhp_default_state=", setup_memhp_default_state); void mem_hotplug_begin(void) { cpus_read_lock(); percpu_down_write(&mem_hotplug_lock); } void mem_hotplug_done(void) { percpu_up_write(&mem_hotplug_lock); cpus_read_unlock(); } u64 max_mem_size = U64_MAX; /* add this memory to iomem resource */ static struct resource *register_memory_resource(u64 start, u64 size, const char *resource_name) { struct resource *res; unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; if (strcmp(resource_name, "System RAM")) flags |= IORESOURCE_SYSRAM_DRIVER_MANAGED; if (!mhp_range_allowed(start, size, true)) return ERR_PTR(-E2BIG); /* * Make sure value parsed from 'mem=' only restricts memory adding * while booting, so that memory hotplug won't be impacted. Please * refer to document of 'mem=' in kernel-parameters.txt for more * details. */ if (start + size > max_mem_size && system_state < SYSTEM_RUNNING) return ERR_PTR(-E2BIG); /* * Request ownership of the new memory range. This might be * a child of an existing resource that was present but * not marked as busy. */ res = __request_region(&iomem_resource, start, size, resource_name, flags); if (!res) { pr_debug("Unable to reserve System RAM region: %016llx->%016llx\n", start, start + size); return ERR_PTR(-EEXIST); } return res; } static void release_memory_resource(struct resource *res) { if (!res) return; release_resource(res); kfree(res); } static int check_pfn_span(unsigned long pfn, unsigned long nr_pages) { /* * Disallow all operations smaller than a sub-section and only * allow operations smaller than a section for * SPARSEMEM_VMEMMAP. Note that check_hotplug_memory_range() * enforces a larger memory_block_size_bytes() granularity for * memory that will be marked online, so this check should only * fire for direct arch_{add,remove}_memory() users outside of * add_memory_resource(). */ unsigned long min_align; if (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) min_align = PAGES_PER_SUBSECTION; else min_align = PAGES_PER_SECTION; if (!IS_ALIGNED(pfn | nr_pages, min_align)) return -EINVAL; return 0; } /* * Return page for the valid pfn only if the page is online. All pfn * walkers which rely on the fully initialized page->flags and others * should use this rather than pfn_valid && pfn_to_page */ struct page *pfn_to_online_page(unsigned long pfn) { unsigned long nr = pfn_to_section_nr(pfn); struct dev_pagemap *pgmap; struct mem_section *ms; if (nr >= NR_MEM_SECTIONS) return NULL; ms = __nr_to_section(nr); if (!online_section(ms)) return NULL; /* * Save some code text when online_section() + * pfn_section_valid() are sufficient. */ if (IS_ENABLED(CONFIG_HAVE_ARCH_PFN_VALID) && !pfn_valid(pfn)) return NULL; if (!pfn_section_valid(ms, pfn)) return NULL; if (!online_device_section(ms)) return pfn_to_page(pfn); /* * Slowpath: when ZONE_DEVICE collides with * ZONE_{NORMAL,MOVABLE} within the same section some pfns in * the section may be 'offline' but 'valid'. Only * get_dev_pagemap() can determine sub-section online status. */ pgmap = get_dev_pagemap(pfn, NULL); put_dev_pagemap(pgmap); /* The presence of a pgmap indicates ZONE_DEVICE offline pfn */ if (pgmap) return NULL; return pfn_to_page(pfn); } EXPORT_SYMBOL_GPL(pfn_to_online_page); int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, struct mhp_params *params) { const unsigned long end_pfn = pfn + nr_pages; unsigned long cur_nr_pages; int err; struct vmem_altmap *altmap = params->altmap; if (WARN_ON_ONCE(!pgprot_val(params->pgprot))) return -EINVAL; VM_BUG_ON(!mhp_range_allowed(PFN_PHYS(pfn), nr_pages * PAGE_SIZE, false)); if (altmap) { /* * Validate altmap is within bounds of the total request */ if (altmap->base_pfn != pfn || vmem_altmap_offset(altmap) > nr_pages) { pr_warn_once("memory add fail, invalid altmap\n"); return -EINVAL; } altmap->alloc = 0; } if (check_pfn_span(pfn, nr_pages)) { WARN(1, "Misaligned %s start: %#lx end: %#lx\n", __func__, pfn, pfn + nr_pages - 1); return -EINVAL; } for (; pfn < end_pfn; pfn += cur_nr_pages) { /* Select all remaining pages up to the next section boundary */ cur_nr_pages = min(end_pfn - pfn, SECTION_ALIGN_UP(pfn + 1) - pfn); err = sparse_add_section(nid, pfn, cur_nr_pages, altmap, params->pgmap); if (err) break; cond_resched(); } vmemmap_populate_print_last(); return err; } /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, unsigned long start_pfn, unsigned long end_pfn) { for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) { if (unlikely(!pfn_to_online_page(start_pfn))) continue; if (unlikely(pfn_to_nid(start_pfn) != nid)) continue; if (zone != page_zone(pfn_to_page(start_pfn))) continue; return start_pfn; } return 0; } /* find the biggest valid pfn in the range [start_pfn, end_pfn). */ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, unsigned long start_pfn, unsigned long end_pfn) { unsigned long pfn; /* pfn is the end pfn of a memory section. */ pfn = end_pfn - 1; for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) { if (unlikely(!pfn_to_online_page(pfn))) continue; if (unlikely(pfn_to_nid(pfn) != nid)) continue; if (zone != page_zone(pfn_to_page(pfn))) continue; return pfn; } return 0; } static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, unsigned long end_pfn) { unsigned long pfn; int nid = zone_to_nid(zone); if (zone->zone_start_pfn == start_pfn) { /* * If the section is smallest section in the zone, it need * shrink zone->zone_start_pfn and zone->zone_spanned_pages. * In this case, we find second smallest valid mem_section * for shrinking zone. */ pfn = find_smallest_section_pfn(nid, zone, end_pfn, zone_end_pfn(zone)); if (pfn) { zone->spanned_pages = zone_end_pfn(zone) - pfn; zone->zone_start_pfn = pfn; } else { zone->zone_start_pfn = 0; zone->spanned_pages = 0; } } else if (zone_end_pfn(zone) == end_pfn) { /* * If the section is biggest section in the zone, it need * shrink zone->spanned_pages. * In this case, we find second biggest valid mem_section for * shrinking zone. */ pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn, start_pfn); if (pfn) zone->spanned_pages = pfn - zone->zone_start_pfn + 1; else { zone->zone_start_pfn = 0; zone->spanned_pages = 0; } } } static void update_pgdat_span(struct pglist_data *pgdat) { unsigned long node_start_pfn = 0, node_end_pfn = 0; struct zone *zone; for (zone = pgdat->node_zones; zone < pgdat->node_zones + MAX_NR_ZONES; zone++) { unsigned long end_pfn = zone_end_pfn(zone); /* No need to lock the zones, they can't change. */ if (!zone->spanned_pages) continue; if (!node_end_pfn) { node_start_pfn = zone->zone_start_pfn; node_end_pfn = end_pfn; continue; } if (end_pfn > node_end_pfn) node_end_pfn = end_pfn; if (zone->zone_start_pfn < node_start_pfn) node_start_pfn = zone->zone_start_pfn; } pgdat->node_start_pfn = node_start_pfn; pgdat->node_spanned_pages = node_end_pfn - node_start_pfn; } void __ref remove_pfn_range_from_zone(struct zone *zone, unsigned long start_pfn, unsigned long nr_pages) { const unsigned long end_pfn = start_pfn + nr_pages; struct pglist_data *pgdat = zone->zone_pgdat; unsigned long pfn, cur_nr_pages; /* Poison struct pages because they are now uninitialized again. */ for (pfn = start_pfn; pfn < end_pfn; pfn += cur_nr_pages) { cond_resched(); /* Select all remaining pages up to the next section boundary */ cur_nr_pages = min(end_pfn - pfn, SECTION_ALIGN_UP(pfn + 1) - pfn); page_init_poison(pfn_to_page(pfn), sizeof(struct page) * cur_nr_pages); } /* * Zone shrinking code cannot properly deal with ZONE_DEVICE. So * we will not try to shrink the zones - which is okay as * set_zone_contiguous() cannot deal with ZONE_DEVICE either way. */ if (zone_is_zone_device(zone)) return; clear_zone_contiguous(zone); shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); update_pgdat_span(pgdat); set_zone_contiguous(zone); } /** * __remove_pages() - remove sections of pages * @pfn: starting pageframe (must be aligned to start of a section) * @nr_pages: number of pages to remove (must be multiple of section size) * @altmap: alternative device page map or %NULL if default memmap is used * * Generic helper function to remove section mappings and sysfs entries * for the section of the memory we are removing. Caller needs to make * sure that pages are marked reserved and zones are adjust properly by * calling offline_pages(). */ void __remove_pages(unsigned long pfn, unsigned long nr_pages, struct vmem_altmap *altmap) { const unsigned long end_pfn = pfn + nr_pages; unsigned long cur_nr_pages; if (check_pfn_span(pfn, nr_pages)) { WARN(1, "Misaligned %s start: %#lx end: %#lx\n", __func__, pfn, pfn + nr_pages - 1); return; } for (; pfn < end_pfn; pfn += cur_nr_pages) { cond_resched(); /* Select all remaining pages up to the next section boundary */ cur_nr_pages = min(end_pfn - pfn, SECTION_ALIGN_UP(pfn + 1) - pfn); sparse_remove_section(pfn, cur_nr_pages, altmap); } } int set_online_page_callback(online_page_callback_t callback) { int rc = -EINVAL; get_online_mems(); mutex_lock(&online_page_callback_lock); if (online_page_callback == generic_online_page) { online_page_callback = callback; rc = 0; } mutex_unlock(&online_page_callback_lock); put_online_mems(); return rc; } EXPORT_SYMBOL_GPL(set_online_page_callback); int restore_online_page_callback(online_page_callback_t callback) { int rc = -EINVAL; get_online_mems(); mutex_lock(&online_page_callback_lock); if (online_page_callback == callback) { online_page_callback = generic_online_page; rc = 0; } mutex_unlock(&online_page_callback_lock); put_online_mems(); return rc; } EXPORT_SYMBOL_GPL(restore_online_page_callback); /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ void __ref generic_online_page(struct page *page, unsigned int order) { __free_pages_core(page, order, MEMINIT_HOTPLUG); } EXPORT_SYMBOL_GPL(generic_online_page); static void online_pages_range(unsigned long start_pfn, unsigned long nr_pages) { const unsigned long end_pfn = start_pfn + nr_pages; unsigned long pfn; /* * Online the pages in MAX_PAGE_ORDER aligned chunks. The callback might * decide to not expose all pages to the buddy (e.g., expose them * later). We account all pages as being online and belonging to this * zone ("present"). * When using memmap_on_memory, the range might not be aligned to * MAX_ORDER_NR_PAGES - 1, but pageblock aligned. __ffs() will detect * this and the first chunk to online will be pageblock_nr_pages. */ for (pfn = start_pfn; pfn < end_pfn;) { int order; /* * Free to online pages in the largest chunks alignment allows. * * __ffs() behaviour is undefined for 0. start == 0 is * MAX_PAGE_ORDER-aligned, Set order to MAX_PAGE_ORDER for * the case. */ if (pfn) order = min_t(int, MAX_PAGE_ORDER, __ffs(pfn)); else order = MAX_PAGE_ORDER; (*online_page_callback)(pfn_to_page(pfn), order); pfn += (1UL << order); } /* mark all involved sections as online */ online_mem_sections(start_pfn, end_pfn); } /* check which state of node_states will be changed when online memory */ static void node_states_check_changes_online(unsigned long nr_pages, struct zone *zone, struct memory_notify *arg) { int nid = zone_to_nid(zone); arg->status_change_nid = NUMA_NO_NODE; arg->status_change_nid_normal = NUMA_NO_NODE; if (!node_state(nid, N_MEMORY)) arg->status_change_nid = nid; if (zone_idx(zone) <= ZONE_NORMAL && !node_state(nid, N_NORMAL_MEMORY)) arg->status_change_nid_normal = nid; } static void node_states_set_node(int node, struct memory_notify *arg) { if (arg->status_change_nid_normal >= 0) node_set_state(node, N_NORMAL_MEMORY); if (arg->status_change_nid >= 0) node_set_state(node, N_MEMORY); } static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn, unsigned long nr_pages) { unsigned long old_end_pfn = zone_end_pfn(zone); if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn) zone->zone_start_pfn = start_pfn; zone->spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - zone->zone_start_pfn; } static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned long start_pfn, unsigned long nr_pages) { unsigned long old_end_pfn = pgdat_end_pfn(pgdat); if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn) pgdat->node_start_pfn = start_pfn; pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn; } #ifdef CONFIG_ZONE_DEVICE static void section_taint_zone_device(unsigned long pfn) { struct mem_section *ms = __pfn_to_section(pfn); ms->section_mem_map |= SECTION_TAINT_ZONE_DEVICE; } #else static inline void section_taint_zone_device(unsigned long pfn) { } #endif /* * Associate the pfn range with the given zone, initializing the memmaps * and resizing the pgdat/zone data to span the added pages. After this * call, all affected pages are PageOffline(). * * All aligned pageblocks are initialized to the specified migratetype * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related * zone stats (e.g., nr_isolate_pageblock) are touched. */ void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, unsigned long nr_pages, struct vmem_altmap *altmap, int migratetype) { struct pglist_data *pgdat = zone->zone_pgdat; int nid = pgdat->node_id; clear_zone_contiguous(zone); if (zone_is_empty(zone)) init_currently_empty_zone(zone, start_pfn, nr_pages); resize_zone_range(zone, start_pfn, nr_pages); resize_pgdat_range(pgdat, start_pfn, nr_pages); /* * Subsection population requires care in pfn_to_online_page(). * Set the taint to enable the slow path detection of * ZONE_DEVICE pages in an otherwise ZONE_{NORMAL,MOVABLE} * section. */ if (zone_is_zone_device(zone)) { if (!IS_ALIGNED(start_pfn, PAGES_PER_SECTION)) section_taint_zone_device(start_pfn); if (!IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION)) section_taint_zone_device(start_pfn + nr_pages); } /* * TODO now we have a visible range of pages which are not associated * with their zone properly. Not nice but set_pfnblock_flags_mask * expects the zone spans the pfn range. All the pages in the range * are reserved so nobody should be touching them so we should be safe */ memmap_init_range(nr_pages, nid, zone_idx(zone), start_pfn, 0, MEMINIT_HOTPLUG, altmap, migratetype); set_zone_contiguous(zone); } struct auto_movable_stats { unsigned long kernel_early_pages; unsigned long movable_pages; }; static void auto_movable_stats_account_zone(struct auto_movable_stats *stats, struct zone *zone) { if (zone_idx(zone) == ZONE_MOVABLE) { stats->movable_pages += zone->present_pages; } else { stats->kernel_early_pages += zone->present_early_pages; #ifdef CONFIG_CMA /* * CMA pages (never on hotplugged memory) behave like * ZONE_MOVABLE. */ stats->movable_pages += zone->cma_pages; stats->kernel_early_pages -= zone->cma_pages; #endif /* CONFIG_CMA */ } } struct auto_movable_group_stats { unsigned long movable_pages; unsigned long req_kernel_early_pages; }; static int auto_movable_stats_account_group(struct memory_group *group, void *arg) { const int ratio = READ_ONCE(auto_movable_ratio); struct auto_movable_group_stats *stats = arg; long pages; /* * We don't support modifying the config while the auto-movable online * policy is already enabled. Just avoid the division by zero below. */ if (!ratio) return 0; /* * Calculate how many early kernel pages this group requires to * satisfy the configured zone ratio. */ pages = group->present_movable_pages * 100 / ratio; pages -= group->present_kernel_pages; if (pages > 0) stats->req_kernel_early_pages += pages; stats->movable_pages += group->present_movable_pages; return 0; } static bool auto_movable_can_online_movable(int nid, struct memory_group *group, unsigned long nr_pages) { unsigned long kernel_early_pages, movable_pages; struct auto_movable_group_stats group_stats = {}; struct auto_movable_stats stats = {}; struct zone *zone; int i; /* Walk all relevant zones and collect MOVABLE vs. KERNEL stats. */ if (nid == NUMA_NO_NODE) { /* TODO: cache values */ for_each_populated_zone(zone) auto_movable_stats_account_zone(&stats, zone); } else { for (i = 0; i < MAX_NR_ZONES; i++) { pg_data_t *pgdat = NODE_DATA(nid); zone = pgdat->node_zones + i; if (populated_zone(zone)) auto_movable_stats_account_zone(&stats, zone); } } kernel_early_pages = stats.kernel_early_pages; movable_pages = stats.movable_pages; /* * Kernel memory inside dynamic memory group allows for more MOVABLE * memory within the same group. Remove the effect of all but the * current group from the stats. */ walk_dynamic_memory_groups(nid, auto_movable_stats_account_group, group, &group_stats); if (kernel_early_pages <= group_stats.req_kernel_early_pages) return false; kernel_early_pages -= group_stats.req_kernel_early_pages; movable_pages -= group_stats.movable_pages; if (group && group->is_dynamic) kernel_early_pages += group->present_kernel_pages; /* * Test if we could online the given number of pages to ZONE_MOVABLE * and still stay in the configured ratio. */ movable_pages += nr_pages; return movable_pages <= (auto_movable_ratio * kernel_early_pages) / 100; } /* * Returns a default kernel memory zone for the given pfn range. * If no kernel zone covers this pfn range it will automatically go * to the ZONE_NORMAL. */ static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, unsigned long nr_pages) { struct pglist_data *pgdat = NODE_DATA(nid); int zid; for (zid = 0; zid < ZONE_NORMAL; zid++) { struct zone *zone = &pgdat->node_zones[zid]; if (zone_intersects(zone, start_pfn, nr_pages)) return zone; } return &pgdat->node_zones[ZONE_NORMAL]; } /* * Determine to which zone to online memory dynamically based on user * configuration and system stats. We care about the following ratio: * * MOVABLE : KERNEL * * Whereby MOVABLE is memory in ZONE_MOVABLE and KERNEL is memory in * one of the kernel zones. CMA pages inside one of the kernel zones really * behaves like ZONE_MOVABLE, so we treat them accordingly. * * We don't allow for hotplugged memory in a KERNEL zone to increase the * amount of MOVABLE memory we can have, so we end up with: * * MOVABLE : KERNEL_EARLY * * Whereby KERNEL_EARLY is memory in one of the kernel zones, available sinze * boot. We base our calculation on KERNEL_EARLY internally, because: * * a) Hotplugged memory in one of the kernel zones can sometimes still get * hotunplugged, especially when hot(un)plugging individual memory blocks. * There is no coordination across memory devices, therefore "automatic" * hotunplugging, as implemented in hypervisors, could result in zone * imbalances. * b) Early/boot memory in one of the kernel zones can usually not get * hotunplugged again (e.g., no firmware interface to unplug, fragmented * with unmovable allocations). While there are corner cases where it might * still work, it is barely relevant in practice. * * Exceptions are dynamic memory groups, which allow for more MOVABLE * memory within the same memory group -- because in that case, there is * coordination within the single memory device managed by a single driver. * * We rely on "present pages" instead of "managed pages", as the latter is * highly unreliable and dynamic in virtualized environments, and does not * consider boot time allocations. For example, memory ballooning adjusts the * managed pages when inflating/deflating the balloon, and balloon compaction * can even migrate inflated pages between zones. * * Using "present pages" is better but some things to keep in mind are: * * a) Some memblock allocations, such as for the crashkernel area, are * effectively unused by the kernel, yet they account to "present pages". * Fortunately, these allocations are comparatively small in relevant setups * (e.g., fraction of system memory). * b) Some hotplugged memory blocks in virtualized environments, esecially * hotplugged by virtio-mem, look like they are completely present, however, * only parts of the memory block are actually currently usable. * "present pages" is an upper limit that can get reached at runtime. As * we base our calculations on KERNEL_EARLY, this is not an issue. */ static struct zone *auto_movable_zone_for_pfn(int nid, struct memory_group *group, unsigned long pfn, unsigned long nr_pages) { unsigned long online_pages = 0, max_pages, end_pfn; struct page *page; if (!auto_movable_ratio) goto kernel_zone; if (group && !group->is_dynamic) { max_pages = group->s.max_pages; online_pages = group->present_movable_pages; /* If anything is !MOVABLE online the rest !MOVABLE. */ if (group->present_kernel_pages) goto kernel_zone; } else if (!group || group->d.unit_pages == nr_pages) { max_pages = nr_pages; } else { max_pages = group->d.unit_pages; /* * Take a look at all online sections in the current unit. * We can safely assume that all pages within a section belong * to the same zone, because dynamic memory groups only deal * with hotplugged memory. */ pfn = ALIGN_DOWN(pfn, group->d.unit_pages); end_pfn = pfn + group->d.unit_pages; for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { page = pfn_to_online_page(pfn); if (!page) continue; /* If anything is !MOVABLE online the rest !MOVABLE. */ if (!is_zone_movable_page(page)) goto kernel_zone; online_pages += PAGES_PER_SECTION; } } /* * Online MOVABLE if we could *currently* online all remaining parts * MOVABLE. We expect to (add+) online them immediately next, so if * nobody interferes, all will be MOVABLE if possible. */ nr_pages = max_pages - online_pages; if (!auto_movable_can_online_movable(NUMA_NO_NODE, group, nr_pages)) goto kernel_zone; #ifdef CONFIG_NUMA if (auto_movable_numa_aware && !auto_movable_can_online_movable(nid, group, nr_pages)) goto kernel_zone; #endif /* CONFIG_NUMA */ return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; kernel_zone: return default_kernel_zone_for_pfn(nid, pfn, nr_pages); } static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn, unsigned long nr_pages) { struct zone *kernel_zone = default_kernel_zone_for_pfn(nid, start_pfn, nr_pages); struct zone *movable_zone = &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; bool in_kernel = zone_intersects(kernel_zone, start_pfn, nr_pages); bool in_movable = zone_intersects(movable_zone, start_pfn, nr_pages); /* * We inherit the existing zone in a simple case where zones do not * overlap in the given range */ if (in_kernel ^ in_movable) return (in_kernel) ? kernel_zone : movable_zone; /* * If the range doesn't belong to any zone or two zones overlap in the * given range then we use movable zone only if movable_node is * enabled because we always online to a kernel zone by default. */ return movable_node_enabled ? movable_zone : kernel_zone; } struct zone *zone_for_pfn_range(int online_type, int nid, struct memory_group *group, unsigned long start_pfn, unsigned long nr_pages) { if (online_type == MMOP_ONLINE_KERNEL) return default_kernel_zone_for_pfn(nid, start_pfn, nr_pages); if (online_type == MMOP_ONLINE_MOVABLE) return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; if (online_policy == ONLINE_POLICY_AUTO_MOVABLE) return auto_movable_zone_for_pfn(nid, group, start_pfn, nr_pages); return default_zone_for_pfn(nid, start_pfn, nr_pages); } /* * This function should only be called by memory_block_{online,offline}, * and {online,offline}_pages. */ void adjust_present_page_count(struct page *page, struct memory_group *group, long nr_pages) { struct zone *zone = page_zone(page); const bool movable = zone_idx(zone) == ZONE_MOVABLE; /* * We only support onlining/offlining/adding/removing of complete * memory blocks; therefore, either all is either early or hotplugged. */ if (early_section(__pfn_to_section(page_to_pfn(page)))) zone->present_early_pages += nr_pages; zone->present_pages += nr_pages; zone->zone_pgdat->node_present_pages += nr_pages; if (group && movable) group->present_movable_pages += nr_pages; else if (group && !movable) group->present_kernel_pages += nr_pages; } int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages, struct zone *zone, bool mhp_off_inaccessible) { unsigned long end_pfn = pfn + nr_pages; int ret, i; ret = kasan_add_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages)); if (ret) return ret; /* * Memory block is accessible at this stage and hence poison the struct * pages now. If the memory block is accessible during memory hotplug * addition phase, then page poisining is already performed in * sparse_add_section(). */ if (mhp_off_inaccessible) page_init_poison(pfn_to_page(pfn), sizeof(struct page) * nr_pages); move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_UNMOVABLE); for (i = 0; i < nr_pages; i++) { struct page *page = pfn_to_page(pfn + i); __ClearPageOffline(page); SetPageVmemmapSelfHosted(page); } /* * It might be that the vmemmap_pages fully span sections. If that is * the case, mark those sections online here as otherwise they will be * left offline. */ if (nr_pages >= PAGES_PER_SECTION) online_mem_sections(pfn, ALIGN_DOWN(end_pfn, PAGES_PER_SECTION)); return ret; } void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages) { unsigned long end_pfn = pfn + nr_pages; /* * It might be that the vmemmap_pages fully span sections. If that is * the case, mark those sections offline here as otherwise they will be * left online. */ if (nr_pages >= PAGES_PER_SECTION) offline_mem_sections(pfn, ALIGN_DOWN(end_pfn, PAGES_PER_SECTION)); /* * The pages associated with this vmemmap have been offlined, so * we can reset its state here. */ remove_pfn_range_from_zone(page_zone(pfn_to_page(pfn)), pfn, nr_pages); kasan_remove_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages)); } /* * Must be called with mem_hotplug_lock in write mode. */ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, struct zone *zone, struct memory_group *group) { unsigned long flags; int need_zonelists_rebuild = 0; const int nid = zone_to_nid(zone); int ret; struct memory_notify arg; /* * {on,off}lining is constrained to full memory sections (or more * precisely to memory blocks from the user space POV). * memmap_on_memory is an exception because it reserves initial part * of the physical memory space for vmemmaps. That space is pageblock * aligned. */ if (WARN_ON_ONCE(!nr_pages || !pageblock_aligned(pfn) || !IS_ALIGNED(pfn + nr_pages, PAGES_PER_SECTION))) return -EINVAL; /* associate pfn range with the zone */ move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_ISOLATE); arg.start_pfn = pfn; arg.nr_pages = nr_pages; node_states_check_changes_online(nr_pages, zone, &arg); ret = memory_notify(MEM_GOING_ONLINE, &arg); ret = notifier_to_errno(ret); if (ret) goto failed_addition; /* * Fixup the number of isolated pageblocks before marking the sections * onlining, such that undo_isolate_page_range() works correctly. */ spin_lock_irqsave(&zone->lock, flags); zone->nr_isolate_pageblock += nr_pages / pageblock_nr_pages; spin_unlock_irqrestore(&zone->lock, flags); /* * If this zone is not populated, then it is not in zonelist. * This means the page allocator ignores this zone. * So, zonelist must be updated after online. */ if (!populated_zone(zone)) { need_zonelists_rebuild = 1; setup_zone_pageset(zone); } online_pages_range(pfn, nr_pages); adjust_present_page_count(pfn_to_page(pfn), group, nr_pages); node_states_set_node(nid, &arg); if (need_zonelists_rebuild) build_all_zonelists(NULL); /* Basic onlining is complete, allow allocation of onlined pages. */ undo_isolate_page_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE); /* * Freshly onlined pages aren't shuffled (e.g., all pages are placed to * the tail of the freelist when undoing isolation). Shuffle the whole * zone to make sure the just onlined pages are properly distributed * across the whole freelist - to create an initial shuffle. */ shuffle_zone(zone); /* reinitialise watermarks and update pcp limits */ init_per_zone_wmark_min(); kswapd_run(nid); kcompactd_run(nid); writeback_set_ratelimit(); memory_notify(MEM_ONLINE, &arg); return 0; failed_addition: pr_debug("online_pages [mem %#010llx-%#010llx] failed\n", (unsigned long long) pfn << PAGE_SHIFT, (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); memory_notify(MEM_CANCEL_ONLINE, &arg); remove_pfn_range_from_zone(zone, pfn, nr_pages); return ret; } /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ static pg_data_t __ref *hotadd_init_pgdat(int nid) { struct pglist_data *pgdat; /* * NODE_DATA is preallocated (free_area_init) but its internal * state is not allocated completely. Add missing pieces. * Completely offline nodes stay around and they just need * reintialization. */ pgdat = NODE_DATA(nid); /* init node's zones as empty zones, we don't have any present pages.*/ free_area_init_core_hotplug(pgdat); /* * The node we allocated has no zone fallback lists. For avoiding * to access not-initialized zonelist, build here. */ build_all_zonelists(pgdat); return pgdat; } /* * __try_online_node - online a node if offlined * @nid: the node ID * @set_node_online: Whether we want to online the node * called by cpu_up() to online a node without onlined memory. * * Returns: * 1 -> a new node has been allocated * 0 -> the node is already online * -ENOMEM -> the node could not be allocated */ static int __try_online_node(int nid, bool set_node_online) { pg_data_t *pgdat; int ret = 1; if (node_online(nid)) return 0; pgdat = hotadd_init_pgdat(nid); if (!pgdat) { pr_err("Cannot online node %d due to NULL pgdat\n", nid); ret = -ENOMEM; goto out; } if (set_node_online) { node_set_online(nid); ret = register_one_node(nid); BUG_ON(ret); } out: return ret; } /* * Users of this function always want to online/register the node */ int try_online_node(int nid) { int ret; mem_hotplug_begin(); ret = __try_online_node(nid, true); mem_hotplug_done(); return ret; } static int check_hotplug_memory_range(u64 start, u64 size) { /* memory range must be block size aligned */ if (!size || !IS_ALIGNED(start, memory_block_size_bytes()) || !IS_ALIGNED(size, memory_block_size_bytes())) { pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx", memory_block_size_bytes(), start, size); return -EINVAL; } return 0; } static int online_memory_block(struct memory_block *mem, void *arg) { mem->online_type = mhp_default_online_type; return device_online(&mem->dev); } #ifndef arch_supports_memmap_on_memory static inline bool arch_supports_memmap_on_memory(unsigned long vmemmap_size) { /* * As default, we want the vmemmap to span a complete PMD such that we * can map the vmemmap using a single PMD if supported by the * architecture. */ return IS_ALIGNED(vmemmap_size, PMD_SIZE); } #endif bool mhp_supports_memmap_on_memory(void) { unsigned long vmemmap_size = memory_block_memmap_size(); unsigned long memmap_pages = memory_block_memmap_on_memory_pages(); /* * Besides having arch support and the feature enabled at runtime, we * need a few more assumptions to hold true: * * a) The vmemmap pages span complete PMDs: We don't want vmemmap code * to populate memory from the altmap for unrelated parts (i.e., * other memory blocks) * * b) The vmemmap pages (and thereby the pages that will be exposed to * the buddy) have to cover full pageblocks: memory onlining/offlining * code requires applicable ranges to be page-aligned, for example, to * set the migratetypes properly. * * TODO: Although we have a check here to make sure that vmemmap pages * fully populate a PMD, it is not the right place to check for * this. A much better solution involves improving vmemmap code * to fallback to base pages when trying to populate vmemmap using * altmap as an alternative source of memory, and we do not exactly * populate a single PMD. */ if (!mhp_memmap_on_memory()) return false; /* * Make sure the vmemmap allocation is fully contained * so that we always allocate vmemmap memory from altmap area. */ if (!IS_ALIGNED(vmemmap_size, PAGE_SIZE)) return false; /* * start pfn should be pageblock_nr_pages aligned for correctly * setting migrate types */ if (!pageblock_aligned(memmap_pages)) return false; if (memmap_pages == PHYS_PFN(memory_block_size_bytes())) /* No effective hotplugged memory doesn't make sense. */ return false; return arch_supports_memmap_on_memory(vmemmap_size); } EXPORT_SYMBOL_GPL(mhp_supports_memmap_on_memory); static void __ref remove_memory_blocks_and_altmaps(u64 start, u64 size) { unsigned long memblock_size = memory_block_size_bytes(); u64 cur_start; /* * For memmap_on_memory, the altmaps were added on a per-memblock * basis; we have to process each individual memory block. */ for (cur_start = start; cur_start < start + size; cur_start += memblock_size) { struct vmem_altmap *altmap = NULL; struct memory_block *mem; mem = find_memory_block(pfn_to_section_nr(PFN_DOWN(cur_start))); if (WARN_ON_ONCE(!mem)) continue; altmap = mem->altmap; mem->altmap = NULL; remove_memory_block_devices(cur_start, memblock_size); arch_remove_memory(cur_start, memblock_size, altmap); /* Verify that all vmemmap pages have actually been freed. */ WARN(altmap->alloc, "Altmap not fully unmapped"); kfree(altmap); } } static int create_altmaps_and_memory_blocks(int nid, struct memory_group *group, u64 start, u64 size, mhp_t mhp_flags) { unsigned long memblock_size = memory_block_size_bytes(); u64 cur_start; int ret; for (cur_start = start; cur_start < start + size; cur_start += memblock_size) { struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) }; struct vmem_altmap mhp_altmap = { .base_pfn = PHYS_PFN(cur_start), .end_pfn = PHYS_PFN(cur_start + memblock_size - 1), }; mhp_altmap.free = memory_block_memmap_on_memory_pages(); if (mhp_flags & MHP_OFFLINE_INACCESSIBLE) mhp_altmap.inaccessible = true; params.altmap = kmemdup(&mhp_altmap, sizeof(struct vmem_altmap), GFP_KERNEL); if (!params.altmap) { ret = -ENOMEM; goto out; } /* call arch's memory hotadd */ ret = arch_add_memory(nid, cur_start, memblock_size, ¶ms); if (ret < 0) { kfree(params.altmap); goto out; } /* create memory block devices after memory was added */ ret = create_memory_block_devices(cur_start, memblock_size, params.altmap, group); if (ret) { arch_remove_memory(cur_start, memblock_size, NULL); kfree(params.altmap); goto out; } } return 0; out: if (ret && cur_start != start) remove_memory_blocks_and_altmaps(start, cur_start - start); return ret; } /* * NOTE: The caller must call lock_device_hotplug() to serialize hotplug * and online/offline operations (triggered e.g. by sysfs). * * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) { struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) }; enum memblock_flags memblock_flags = MEMBLOCK_NONE; struct memory_group *group = NULL; u64 start, size; bool new_node = false; int ret; start = res->start; size = resource_size(res); ret = check_hotplug_memory_range(start, size); if (ret) return ret; if (mhp_flags & MHP_NID_IS_MGID) { group = memory_group_find_by_id(nid); if (!group) return -EINVAL; nid = group->nid; } if (!node_possible(nid)) { WARN(1, "node %d was absent from the node_possible_map\n", nid); return -EINVAL; } mem_hotplug_begin(); if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED) memblock_flags = MEMBLOCK_DRIVER_MANAGED; ret = memblock_add_node(start, size, nid, memblock_flags); if (ret) goto error_mem_hotplug_end; } ret = __try_online_node(nid, false); if (ret < 0) goto error; new_node = ret; /* * Self hosted memmap array */ if ((mhp_flags & MHP_MEMMAP_ON_MEMORY) && mhp_supports_memmap_on_memory()) { ret = create_altmaps_and_memory_blocks(nid, group, start, size, mhp_flags); if (ret) goto error; } else { ret = arch_add_memory(nid, start, size, ¶ms); if (ret < 0) goto error; /* create memory block devices after memory was added */ ret = create_memory_block_devices(start, size, NULL, group); if (ret) { arch_remove_memory(start, size, params.altmap); goto error; } } if (new_node) { /* If sysfs file of new node can't be created, cpu on the node * can't be hot-added. There is no rollback way now. * So, check by BUG_ON() to catch it reluctantly.. * We online node here. We can't roll back from here. */ node_set_online(nid); ret = __register_one_node(nid); BUG_ON(ret); } register_memory_blocks_under_node(nid, PFN_DOWN(start), PFN_UP(start + size - 1), MEMINIT_HOTPLUG); /* create new memmap entry */ if (!strcmp(res->name, "System RAM")) firmware_map_add_hotplug(start, start + size, "System RAM"); /* device_online() will take the lock when calling online_pages() */ mem_hotplug_done(); /* * In case we're allowed to merge the resource, flag it and trigger * merging now that adding succeeded. */ if (mhp_flags & MHP_MERGE_RESOURCE) merge_system_ram_resource(res); /* online pages if requested */ if (mhp_default_online_type != MMOP_OFFLINE) walk_memory_blocks(start, size, NULL, online_memory_block); return ret; error: if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) memblock_remove(start, size); error_mem_hotplug_end: mem_hotplug_done(); return ret; } /* requires device_hotplug_lock, see add_memory_resource() */ int __ref __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) { struct resource *res; int ret; res = register_memory_resource(start, size, "System RAM"); if (IS_ERR(res)) return PTR_ERR(res); ret = add_memory_resource(nid, res, mhp_flags); if (ret < 0) release_memory_resource(res); return ret; } int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) { int rc; lock_device_hotplug(); rc = __add_memory(nid, start, size, mhp_flags); unlock_device_hotplug(); return rc; } EXPORT_SYMBOL_GPL(add_memory); /* * Add special, driver-managed memory to the system as system RAM. Such * memory is not exposed via the raw firmware-provided memmap as system * RAM, instead, it is detected and added by a driver - during cold boot, * after a reboot, and after kexec. * * Reasons why this memory should not be used for the initial memmap of a * kexec kernel or for placing kexec images: * - The booting kernel is in charge of determining how this memory will be * used (e.g., use persistent memory as system RAM) * - Coordination with a hypervisor is required before this memory * can be used (e.g., inaccessible parts). * * For this memory, no entries in /sys/firmware/memmap ("raw firmware-provided * memory map") are created. Also, the created memory resource is flagged * with IORESOURCE_SYSRAM_DRIVER_MANAGED, so in-kernel users can special-case * this memory as well (esp., not place kexec images onto it). * * The resource_name (visible via /proc/iomem) has to have the format * "System RAM ($DRIVER)". */ int add_memory_driver_managed(int nid, u64 start, u64 size, const char *resource_name, mhp_t mhp_flags) { struct resource *res; int rc; if (!resource_name || strstr(resource_name, "System RAM (") != resource_name || resource_name[strlen(resource_name) - 1] != ')') return -EINVAL; lock_device_hotplug(); res = register_memory_resource(start, size, resource_name); if (IS_ERR(res)) { rc = PTR_ERR(res); goto out_unlock; } rc = add_memory_resource(nid, res, mhp_flags); if (rc < 0) release_memory_resource(res); out_unlock: unlock_device_hotplug(); return rc; } EXPORT_SYMBOL_GPL(add_memory_driver_managed); /* * Platforms should define arch_get_mappable_range() that provides * maximum possible addressable physical memory range for which the * linear mapping could be created. The platform returned address * range must adhere to these following semantics. * * - range.start <= range.end * - Range includes both end points [range.start..range.end] * * There is also a fallback definition provided here, allowing the * entire possible physical address range in case any platform does * not define arch_get_mappable_range(). */ struct range __weak arch_get_mappable_range(void) { struct range mhp_range = { .start = 0UL, .end = -1ULL, }; return mhp_range; } struct range mhp_get_pluggable_range(bool need_mapping) { const u64 max_phys = PHYSMEM_END; struct range mhp_range; if (need_mapping) { mhp_range = arch_get_mappable_range(); if (mhp_range.start > max_phys) { mhp_range.start = 0; mhp_range.end = 0; } mhp_range.end = min_t(u64, mhp_range.end, max_phys); } else { mhp_range.start = 0; mhp_range.end = max_phys; } return mhp_range; } EXPORT_SYMBOL_GPL(mhp_get_pluggable_range); bool mhp_range_allowed(u64 start, u64 size, bool need_mapping) { struct range mhp_range = mhp_get_pluggable_range(need_mapping); u64 end = start + size; if (start < end && start >= mhp_range.start && (end - 1) <= mhp_range.end) return true; pr_warn("Hotplug memory [%#llx-%#llx] exceeds maximum addressable range [%#llx-%#llx]\n", start, end, mhp_range.start, mhp_range.end); return false; } #ifdef CONFIG_MEMORY_HOTREMOVE /* * Scan pfn range [start,end) to find movable/migratable pages (LRU pages, * non-lru movable pages and hugepages). Will skip over most unmovable * pages (esp., pages that can be skipped when offlining), but bail out on * definitely unmovable pages. * * Returns: * 0 in case a movable page is found and movable_pfn was updated. * -ENOENT in case no movable page was found. * -EBUSY in case a definitely unmovable page was found. */ static int scan_movable_pages(unsigned long start, unsigned long end, unsigned long *movable_pfn) { unsigned long pfn; for (pfn = start; pfn < end; pfn++) { struct page *page; struct folio *folio; if (!pfn_valid(pfn)) continue; page = pfn_to_page(pfn); if (PageLRU(page)) goto found; if (__PageMovable(page)) goto found; /* * PageOffline() pages that are not marked __PageMovable() and * have a reference count > 0 (after MEM_GOING_OFFLINE) are * definitely unmovable. If their reference count would be 0, * they could at least be skipped when offlining memory. */ if (PageOffline(page) && page_count(page)) return -EBUSY; if (!PageHuge(page)) continue; folio = page_folio(page); /* * This test is racy as we hold no reference or lock. The * hugetlb page could have been free'ed and head is no longer * a hugetlb page before the following check. In such unlikely * cases false positives and negatives are possible. Calling * code must deal with these scenarios. */ if (folio_test_hugetlb_migratable(folio)) goto found; pfn |= folio_nr_pages(folio) - 1; } return -ENOENT; found: *movable_pfn = pfn; return 0; } static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) { unsigned long pfn; struct page *page, *head; LIST_HEAD(source); static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); for (pfn = start_pfn; pfn < end_pfn; pfn++) { struct folio *folio; bool isolated; if (!pfn_valid(pfn)) continue; page = pfn_to_page(pfn); folio = page_folio(page); head = &folio->page; if (PageHuge(page)) { pfn = page_to_pfn(head) + compound_nr(head) - 1; isolate_hugetlb(folio, &source); continue; } else if (PageTransHuge(page)) pfn = page_to_pfn(head) + thp_nr_pages(page) - 1; /* * HWPoison pages have elevated reference counts so the migration would * fail on them. It also doesn't make any sense to migrate them in the * first place. Still try to unmap such a page in case it is still mapped * (e.g. current hwpoison implementation doesn't unmap KSM pages but keep * the unmap as the catch all safety net). */ if (PageHWPoison(page)) { if (WARN_ON(folio_test_lru(folio))) folio_isolate_lru(folio); if (folio_mapped(folio)) try_to_unmap(folio, TTU_IGNORE_MLOCK); continue; } if (!get_page_unless_zero(page)) continue; /* * We can skip free pages. And we can deal with pages on * LRU and non-lru movable pages. */ if (PageLRU(page)) isolated = isolate_lru_page(page); else isolated = isolate_movable_page(page, ISOLATE_UNEVICTABLE); if (isolated) { list_add_tail(&page->lru, &source); if (!__PageMovable(page)) inc_node_page_state(page, NR_ISOLATED_ANON + page_is_file_lru(page)); } else { if (__ratelimit(&migrate_rs)) { pr_warn("failed to isolate pfn %lx\n", pfn); dump_page(page, "isolation failed"); } } put_page(page); } if (!list_empty(&source)) { nodemask_t nmask = node_states[N_MEMORY]; struct migration_target_control mtc = { .nmask = &nmask, .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL, .reason = MR_MEMORY_HOTPLUG, }; int ret; /* * We have checked that migration range is on a single zone so * we can use the nid of the first page to all the others. */ mtc.nid = page_to_nid(list_first_entry(&source, struct page, lru)); /* * try to allocate from a different node but reuse this node * if there are no other online nodes to be used (e.g. we are * offlining a part of the only existing node) */ node_clear(mtc.nid, nmask); if (nodes_empty(nmask)) node_set(mtc.nid, nmask); ret = migrate_pages(&source, alloc_migration_target, NULL, (unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_HOTPLUG, NULL); if (ret) { list_for_each_entry(page, &source, lru) { if (__ratelimit(&migrate_rs)) { pr_warn("migrating pfn %lx failed ret:%d\n", page_to_pfn(page), ret); dump_page(page, "migration failure"); } } putback_movable_pages(&source); } } } static int __init cmdline_parse_movable_node(char *p) { movable_node_enabled = true; return 0; } early_param("movable_node", cmdline_parse_movable_node); /* check which state of node_states will be changed when offline memory */ static void node_states_check_changes_offline(unsigned long nr_pages, struct zone *zone, struct memory_notify *arg) { struct pglist_data *pgdat = zone->zone_pgdat; unsigned long present_pages = 0; enum zone_type zt; arg->status_change_nid = NUMA_NO_NODE; arg->status_change_nid_normal = NUMA_NO_NODE; /* * Check whether node_states[N_NORMAL_MEMORY] will be changed. * If the memory to be offline is within the range * [0..ZONE_NORMAL], and it is the last present memory there, * the zones in that range will become empty after the offlining, * thus we can determine that we need to clear the node from * node_states[N_NORMAL_MEMORY]. */ for (zt = 0; zt <= ZONE_NORMAL; zt++) present_pages += pgdat->node_zones[zt].present_pages; if (zone_idx(zone) <= ZONE_NORMAL && nr_pages >= present_pages) arg->status_change_nid_normal = zone_to_nid(zone); /* * We have accounted the pages from [0..ZONE_NORMAL); ZONE_HIGHMEM * does not apply as we don't support 32bit. * Here we count the possible pages from ZONE_MOVABLE. * If after having accounted all the pages, we see that the nr_pages * to be offlined is over or equal to the accounted pages, * we know that the node will become empty, and so, we can clear * it for N_MEMORY as well. */ present_pages += pgdat->node_zones[ZONE_MOVABLE].present_pages; if (nr_pages >= present_pages) arg->status_change_nid = zone_to_nid(zone); } static void node_states_clear_node(int node, struct memory_notify *arg) { if (arg->status_change_nid_normal >= 0) node_clear_state(node, N_NORMAL_MEMORY); if (arg->status_change_nid >= 0) node_clear_state(node, N_MEMORY); } static int count_system_ram_pages_cb(unsigned long start_pfn, unsigned long nr_pages, void *data) { unsigned long *nr_system_ram_pages = data; *nr_system_ram_pages += nr_pages; return 0; } /* * Must be called with mem_hotplug_lock in write mode. */ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages, struct zone *zone, struct memory_group *group) { const unsigned long end_pfn = start_pfn + nr_pages; unsigned long pfn, managed_pages, system_ram_pages = 0; const int node = zone_to_nid(zone); unsigned long flags; struct memory_notify arg; char *reason; int ret; /* * {on,off}lining is constrained to full memory sections (or more * precisely to memory blocks from the user space POV). * memmap_on_memory is an exception because it reserves initial part * of the physical memory space for vmemmaps. That space is pageblock * aligned. */ if (WARN_ON_ONCE(!nr_pages || !pageblock_aligned(start_pfn) || !IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION))) return -EINVAL; /* * Don't allow to offline memory blocks that contain holes. * Consequently, memory blocks with holes can never get onlined * via the hotplug path - online_pages() - as hotplugged memory has * no holes. This way, we don't have to worry about memory holes, * don't need pfn_valid() checks, and can avoid using * walk_system_ram_range() later. */ walk_system_ram_range(start_pfn, nr_pages, &system_ram_pages, count_system_ram_pages_cb); if (system_ram_pages != nr_pages) { ret = -EINVAL; reason = "memory holes"; goto failed_removal; } /* * We only support offlining of memory blocks managed by a single zone, * checked by calling code. This is just a sanity check that we might * want to remove in the future. */ if (WARN_ON_ONCE(page_zone(pfn_to_page(start_pfn)) != zone || page_zone(pfn_to_page(end_pfn - 1)) != zone)) { ret = -EINVAL; reason = "multizone range"; goto failed_removal; } /* * Disable pcplists so that page isolation cannot race with freeing * in a way that pages from isolated pageblock are left on pcplists. */ zone_pcp_disable(zone); lru_cache_disable(); /* set above range as isolated */ ret = start_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE, MEMORY_OFFLINE | REPORT_FAILURE, GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL); if (ret) { reason = "failure to isolate range"; goto failed_removal_pcplists_disabled; } arg.start_pfn = start_pfn; arg.nr_pages = nr_pages; node_states_check_changes_offline(nr_pages, zone, &arg); ret = memory_notify(MEM_GOING_OFFLINE, &arg); ret = notifier_to_errno(ret); if (ret) { reason = "notifier failure"; goto failed_removal_isolated; } do { pfn = start_pfn; do { /* * Historically we always checked for any signal and * can't limit it to fatal signals without eventually * breaking user space. */ if (signal_pending(current)) { ret = -EINTR; reason = "signal backoff"; goto failed_removal_isolated; } cond_resched(); ret = scan_movable_pages(pfn, end_pfn, &pfn); if (!ret) { /* * TODO: fatal migration failures should bail * out */ do_migrate_range(pfn, end_pfn); } } while (!ret); if (ret != -ENOENT) { reason = "unmovable page"; goto failed_removal_isolated; } /* * Dissolve free hugetlb folios in the memory block before doing * offlining actually in order to make hugetlbfs's object * counting consistent. */ ret = dissolve_free_hugetlb_folios(start_pfn, end_pfn); if (ret) { reason = "failure to dissolve huge pages"; goto failed_removal_isolated; } ret = test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE); } while (ret); /* Mark all sections offline and remove free pages from the buddy. */ managed_pages = __offline_isolated_pages(start_pfn, end_pfn); pr_debug("Offlined Pages %ld\n", nr_pages); /* * The memory sections are marked offline, and the pageblock flags * effectively stale; nobody should be touching them. Fixup the number * of isolated pageblocks, memory onlining will properly revert this. */ spin_lock_irqsave(&zone->lock, flags); zone->nr_isolate_pageblock -= nr_pages / pageblock_nr_pages; spin_unlock_irqrestore(&zone->lock, flags); lru_cache_enable(); zone_pcp_enable(zone); /* removal success */ adjust_managed_page_count(pfn_to_page(start_pfn), -managed_pages); adjust_present_page_count(pfn_to_page(start_pfn), group, -nr_pages); /* reinitialise watermarks and update pcp limits */ init_per_zone_wmark_min(); /* * Make sure to mark the node as memory-less before rebuilding the zone * list. Otherwise this node would still appear in the fallback lists. */ node_states_clear_node(node, &arg); if (!populated_zone(zone)) { zone_pcp_reset(zone); build_all_zonelists(NULL); } if (arg.status_change_nid >= 0) { kcompactd_stop(node); kswapd_stop(node); } writeback_set_ratelimit(); memory_notify(MEM_OFFLINE, &arg); remove_pfn_range_from_zone(zone, start_pfn, nr_pages); return 0; failed_removal_isolated: /* pushback to free area */ undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); memory_notify(MEM_CANCEL_OFFLINE, &arg); failed_removal_pcplists_disabled: lru_cache_enable(); zone_pcp_enable(zone); failed_removal: pr_debug("memory offlining [mem %#010llx-%#010llx] failed due to %s\n", (unsigned long long) start_pfn << PAGE_SHIFT, ((unsigned long long) end_pfn << PAGE_SHIFT) - 1, reason); return ret; } static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) { int *nid = arg; *nid = mem->nid; if (unlikely(mem->state != MEM_OFFLINE)) { phys_addr_t beginpa, endpa; beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); endpa = beginpa + memory_block_size_bytes() - 1; pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", &beginpa, &endpa); return -EBUSY; } return 0; } static int count_memory_range_altmaps_cb(struct memory_block *mem, void *arg) { u64 *num_altmaps = (u64 *)arg; if (mem->altmap) *num_altmaps += 1; return 0; } static int check_cpu_on_node(int nid) { int cpu; for_each_present_cpu(cpu) { if (cpu_to_node(cpu) == nid) /* * the cpu on this node isn't removed, and we can't * offline this node. */ return -EBUSY; } return 0; } static int check_no_memblock_for_node_cb(struct memory_block *mem, void *arg) { int nid = *(int *)arg; /* * If a memory block belongs to multiple nodes, the stored nid is not * reliable. However, such blocks are always online (e.g., cannot get * offlined) and, therefore, are still spanned by the node. */ return mem->nid == nid ? -EEXIST : 0; } /** * try_offline_node * @nid: the node ID * * Offline a node if all memory sections and cpus of the node are removed. * * NOTE: The caller must call lock_device_hotplug() to serialize hotplug * and online/offline operations before this call. */ void try_offline_node(int nid) { int rc; /* * If the node still spans pages (especially ZONE_DEVICE), don't * offline it. A node spans memory after move_pfn_range_to_zone(), * e.g., after the memory block was onlined. */ if (node_spanned_pages(nid)) return; /* * Especially offline memory blocks might not be spanned by the * node. They will get spanned by the node once they get onlined. * However, they link to the node in sysfs and can get onlined later. */ rc = for_each_memory_block(&nid, check_no_memblock_for_node_cb); if (rc) return; if (check_cpu_on_node(nid)) return; /* * all memory/cpu of this node are removed, we can offline this * node now. */ node_set_offline(nid); unregister_one_node(nid); } EXPORT_SYMBOL(try_offline_node); static int memory_blocks_have_altmaps(u64 start, u64 size) { u64 num_memblocks = size / memory_block_size_bytes(); u64 num_altmaps = 0; if (!mhp_memmap_on_memory()) return 0; walk_memory_blocks(start, size, &num_altmaps, count_memory_range_altmaps_cb); if (num_altmaps == 0) return 0; if (WARN_ON_ONCE(num_memblocks != num_altmaps)) return -EINVAL; return 1; } static int __ref try_remove_memory(u64 start, u64 size) { int rc, nid = NUMA_NO_NODE; BUG_ON(check_hotplug_memory_range(start, size)); /* * All memory blocks must be offlined before removing memory. Check * whether all memory blocks in question are offline and return error * if this is not the case. * * While at it, determine the nid. Note that if we'd have mixed nodes, * we'd only try to offline the last determined one -- which is good * enough for the cases we care about. */ rc = walk_memory_blocks(start, size, &nid, check_memblock_offlined_cb); if (rc) return rc; /* remove memmap entry */ firmware_map_remove(start, start + size, "System RAM"); mem_hotplug_begin(); rc = memory_blocks_have_altmaps(start, size); if (rc < 0) { mem_hotplug_done(); return rc; } else if (!rc) { /* * Memory block device removal under the device_hotplug_lock is * a barrier against racing online attempts. * No altmaps present, do the removal directly */ remove_memory_block_devices(start, size); arch_remove_memory(start, size, NULL); } else { /* all memblocks in the range have altmaps */ remove_memory_blocks_and_altmaps(start, size); } if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) memblock_remove(start, size); release_mem_region_adjustable(start, size); if (nid != NUMA_NO_NODE) try_offline_node(nid); mem_hotplug_done(); return 0; } /** * __remove_memory - Remove memory if every memory block is offline * @start: physical address of the region to remove * @size: size of the region to remove * * NOTE: The caller must call lock_device_hotplug() to serialize hotplug * and online/offline operations before this call, as required by * try_offline_node(). */ void __remove_memory(u64 start, u64 size) { /* * trigger BUG() if some memory is not offlined prior to calling this * function */ if (try_remove_memory(start, size)) BUG(); } /* * Remove memory if every memory block is offline, otherwise return -EBUSY is * some memory is not offline */ int remove_memory(u64 start, u64 size) { int rc; lock_device_hotplug(); rc = try_remove_memory(start, size); unlock_device_hotplug(); return rc; } EXPORT_SYMBOL_GPL(remove_memory); static int try_offline_memory_block(struct memory_block *mem, void *arg) { uint8_t online_type = MMOP_ONLINE_KERNEL; uint8_t **online_types = arg; struct page *page; int rc; /* * Sense the online_type via the zone of the memory block. Offlining * with multiple zones within one memory block will be rejected * by offlining code ... so we don't care about that. */ page = pfn_to_online_page(section_nr_to_pfn(mem->start_section_nr)); if (page && zone_idx(page_zone(page)) == ZONE_MOVABLE) online_type = MMOP_ONLINE_MOVABLE; rc = device_offline(&mem->dev); /* * Default is MMOP_OFFLINE - change it only if offlining succeeded, * so try_reonline_memory_block() can do the right thing. */ if (!rc) **online_types = online_type; (*online_types)++; /* Ignore if already offline. */ return rc < 0 ? rc : 0; } static int try_reonline_memory_block(struct memory_block *mem, void *arg) { uint8_t **online_types = arg; int rc; if (**online_types != MMOP_OFFLINE) { mem->online_type = **online_types; rc = device_online(&mem->dev); if (rc < 0) pr_warn("%s: Failed to re-online memory: %d", __func__, rc); } /* Continue processing all remaining memory blocks. */ (*online_types)++; return 0; } /* * Try to offline and remove memory. Might take a long time to finish in case * memory is still in use. Primarily useful for memory devices that logically * unplugged all memory (so it's no longer in use) and want to offline + remove * that memory. */ int offline_and_remove_memory(u64 start, u64 size) { const unsigned long mb_count = size / memory_block_size_bytes(); uint8_t *online_types, *tmp; int rc; if (!IS_ALIGNED(start, memory_block_size_bytes()) || !IS_ALIGNED(size, memory_block_size_bytes()) || !size) return -EINVAL; /* * We'll remember the old online type of each memory block, so we can * try to revert whatever we did when offlining one memory block fails * after offlining some others succeeded. */ online_types = kmalloc_array(mb_count, sizeof(*online_types), GFP_KERNEL); if (!online_types) return -ENOMEM; /* * Initialize all states to MMOP_OFFLINE, so when we abort processing in * try_offline_memory_block(), we'll skip all unprocessed blocks in * try_reonline_memory_block(). */ memset(online_types, MMOP_OFFLINE, mb_count); lock_device_hotplug(); tmp = online_types; rc = walk_memory_blocks(start, size, &tmp, try_offline_memory_block); /* * In case we succeeded to offline all memory, remove it. * This cannot fail as it cannot get onlined in the meantime. */ if (!rc) { rc = try_remove_memory(start, size); if (rc) pr_err("%s: Failed to remove memory: %d", __func__, rc); } /* * Rollback what we did. While memory onlining might theoretically fail * (nacked by a notifier), it barely ever happens. */ if (rc) { tmp = online_types; walk_memory_blocks(start, size, &tmp, try_reonline_memory_block); } unlock_device_hotplug(); kfree(online_types); return rc; } EXPORT_SYMBOL_GPL(offline_and_remove_memory); #endif /* CONFIG_MEMORY_HOTREMOVE */
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