diff options
Diffstat (limited to 'mm/memory_hotplug.c')
| -rw-r--r-- | mm/memory_hotplug.c | 2706 |
1 files changed, 1624 insertions, 1082 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index b9a667d36c55..a63ec679d861 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * linux/mm/memory_hotplug.c * @@ -12,7 +13,6 @@ #include <linux/pagemap.h> #include <linux/compiler.h> #include <linux/export.h> -#include <linux/pagevec.h> #include <linux/writeback.h> #include <linux/slab.h> #include <linux/sysctl.h> @@ -20,7 +20,6 @@ #include <linux/memory.h> #include <linux/memremap.h> #include <linux/memory_hotplug.h> -#include <linux/highmem.h> #include <linux/vmalloc.h> #include <linux/ioport.h> #include <linux/delay.h> @@ -35,10 +34,167 @@ #include <linux/memblock.h> #include <linux/compaction.h> #include <linux/rmap.h> +#include <linux/module.h> +#include <linux/node.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. @@ -47,8 +203,6 @@ * and restore_online_page_callback() for generic callback restore. */ -static void generic_online_page(struct page *page); - static online_page_callback_t online_page_callback = generic_online_page; static DEFINE_MUTEX(online_page_callback_lock); @@ -66,19 +220,37 @@ void put_online_mems(void) bool movable_node_enabled = false; -#ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE -bool memhp_auto_online; -#else -bool memhp_auto_online = true; -#endif -EXPORT_SYMBOL_GPL(memhp_auto_online); +static int mhp_default_online_type = -1; +int mhp_get_default_online_type(void) +{ + if (mhp_default_online_type >= 0) + return mhp_default_online_type; + + if (IS_ENABLED(CONFIG_MHP_DEFAULT_ONLINE_TYPE_OFFLINE)) + mhp_default_online_type = MMOP_OFFLINE; + else if (IS_ENABLED(CONFIG_MHP_DEFAULT_ONLINE_TYPE_ONLINE_AUTO)) + mhp_default_online_type = MMOP_ONLINE; + else if (IS_ENABLED(CONFIG_MHP_DEFAULT_ONLINE_TYPE_ONLINE_KERNEL)) + mhp_default_online_type = MMOP_ONLINE_KERNEL; + else if (IS_ENABLED(CONFIG_MHP_DEFAULT_ONLINE_TYPE_ONLINE_MOVABLE)) + mhp_default_online_type = MMOP_ONLINE_MOVABLE; + else + mhp_default_online_type = MMOP_OFFLINE; + + return mhp_default_online_type; +} + +void mhp_set_default_online_type(int online_type) +{ + mhp_default_online_type = online_type; +} static int __init setup_memhp_default_state(char *str) { - if (!strcmp(str, "online")) - memhp_auto_online = true; - else if (!strcmp(str, "offline")) - memhp_auto_online = false; + const int online_type = mhp_online_type_from_str(str); + + if (online_type >= 0) + mhp_default_online_type = online_type; return 1; } @@ -96,27 +268,41 @@ void mem_hotplug_done(void) 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) +static struct resource *register_memory_resource(u64 start, u64 size, + const char *resource_name) { - struct resource *res, *conflict; - res = kzalloc(sizeof(struct resource), GFP_KERNEL); - if (!res) - return ERR_PTR(-ENOMEM); - - res->name = "System RAM"; - res->start = start; - res->end = start + size - 1; - res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; - conflict = request_resource_conflict(&iomem_resource, res); - if (conflict) { - if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) { - pr_debug("Device unaddressable memory block " - "memory hotplug at %#010llx !\n", - (unsigned long long)start); - } - pr_debug("System RAM resource %pR cannot be added\n", res); - kfree(res); + 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; @@ -128,210 +314,135 @@ static void release_memory_resource(struct resource *res) return; release_resource(res); kfree(res); - return; -} - -#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE -void get_page_bootmem(unsigned long info, struct page *page, - unsigned long type) -{ - page->freelist = (void *)type; - SetPagePrivate(page); - set_page_private(page, info); - page_ref_inc(page); } -void put_page_bootmem(struct page *page) +static int check_pfn_span(unsigned long pfn, unsigned long nr_pages) { - unsigned long type; - - type = (unsigned long) page->freelist; - BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || - type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE); + /* + * 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 (page_ref_dec_return(page) == 1) { - page->freelist = NULL; - ClearPagePrivate(page); - set_page_private(page, 0); - INIT_LIST_HEAD(&page->lru); - free_reserved_page(page); - } + 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; } -#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE -#ifndef CONFIG_SPARSEMEM_VMEMMAP -static void register_page_bootmem_info_section(unsigned long start_pfn) +/* + * 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 *usemap, mapsize, section_nr, i; + unsigned long nr = pfn_to_section_nr(pfn); + struct dev_pagemap *pgmap; struct mem_section *ms; - struct page *page, *memmap; - section_nr = pfn_to_section_nr(start_pfn); - ms = __nr_to_section(section_nr); + if (nr >= NR_MEM_SECTIONS) + return NULL; - /* Get section's memmap address */ - memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); + ms = __nr_to_section(nr); + if (!online_section(ms)) + return NULL; /* - * Get page for the memmap's phys address - * XXX: need more consideration for sparse_vmemmap... + * Save some code text when online_section() + + * pfn_section_valid() are sufficient. */ - page = virt_to_page(memmap); - mapsize = sizeof(struct page) * PAGES_PER_SECTION; - mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT; - - /* remember memmap's page */ - for (i = 0; i < mapsize; i++, page++) - get_page_bootmem(section_nr, page, SECTION_INFO); - - usemap = ms->pageblock_flags; - page = virt_to_page(usemap); - - mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; - - for (i = 0; i < mapsize; i++, page++) - get_page_bootmem(section_nr, page, MIX_SECTION_INFO); - -} -#else /* CONFIG_SPARSEMEM_VMEMMAP */ -static void register_page_bootmem_info_section(unsigned long start_pfn) -{ - unsigned long *usemap, mapsize, section_nr, i; - struct mem_section *ms; - struct page *page, *memmap; - - section_nr = pfn_to_section_nr(start_pfn); - ms = __nr_to_section(section_nr); - - memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); - - register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); + if (IS_ENABLED(CONFIG_HAVE_ARCH_PFN_VALID) && !pfn_valid(pfn)) + return NULL; - usemap = ms->pageblock_flags; - page = virt_to_page(usemap); + if (!pfn_section_valid(ms, pfn)) + return NULL; - mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; + if (!online_device_section(ms)) + return pfn_to_page(pfn); - for (i = 0; i < mapsize; i++, page++) - get_page_bootmem(section_nr, page, MIX_SECTION_INFO); -} -#endif /* !CONFIG_SPARSEMEM_VMEMMAP */ - -void __init register_page_bootmem_info_node(struct pglist_data *pgdat) -{ - unsigned long i, pfn, end_pfn, nr_pages; - int node = pgdat->node_id; - struct page *page; - - nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT; - page = virt_to_page(pgdat); - - for (i = 0; i < nr_pages; i++, page++) - get_page_bootmem(node, page, NODE_INFO); + /* + * 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); + put_dev_pagemap(pgmap); - pfn = pgdat->node_start_pfn; - end_pfn = pgdat_end_pfn(pgdat); + /* The presence of a pgmap indicates ZONE_DEVICE offline pfn */ + if (pgmap) + return NULL; - /* register section info */ - for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { - /* - * Some platforms can assign the same pfn to multiple nodes - on - * node0 as well as nodeN. To avoid registering a pfn against - * multiple nodes we check that this pfn does not already - * reside in some other nodes. - */ - if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node)) - register_page_bootmem_info_section(pfn); - } + return pfn_to_page(pfn); } -#endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ +EXPORT_SYMBOL_GPL(pfn_to_online_page); -static int __meminit __add_section(int nid, unsigned long phys_start_pfn, - struct vmem_altmap *altmap, bool want_memblock) +int __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, + struct mhp_params *params) { - int ret; - - if (pfn_valid(phys_start_pfn)) - return -EEXIST; + const unsigned long end_pfn = pfn + nr_pages; + unsigned long cur_nr_pages; + int err; + struct vmem_altmap *altmap = params->altmap; - ret = sparse_add_one_section(nid, phys_start_pfn, altmap); - if (ret < 0) - return ret; - - if (!want_memblock) - return 0; - - return hotplug_memory_register(nid, __pfn_to_section(phys_start_pfn)); -} - -/* - * Reasonably generic function for adding memory. It is - * expected that archs that support memory hotplug will - * call this function after deciding the zone to which to - * add the new pages. - */ -int __ref __add_pages(int nid, unsigned long phys_start_pfn, - unsigned long nr_pages, struct vmem_altmap *altmap, - bool want_memblock) -{ - unsigned long i; - int err = 0; - int start_sec, end_sec; + if (WARN_ON_ONCE(!pgprot_val(params->pgprot))) + return -EINVAL; - /* during initialize mem_map, align hot-added range to section */ - start_sec = pfn_to_section_nr(phys_start_pfn); - end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); + 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 != phys_start_pfn + if (altmap->base_pfn != pfn || vmem_altmap_offset(altmap) > nr_pages) { pr_warn_once("memory add fail, invalid altmap\n"); - err = -EINVAL; - goto out; + return -EINVAL; } altmap->alloc = 0; } - for (i = start_sec; i <= end_sec; i++) { - err = __add_section(nid, section_nr_to_pfn(i), altmap, - want_memblock); + if (check_pfn_span(pfn, nr_pages)) { + WARN(1, "Misaligned %s start: %#lx end: %#lx\n", __func__, pfn, pfn + nr_pages - 1); + return -EINVAL; + } - /* - * EEXIST is finally dealt with by ioresource collision - * check. see add_memory() => register_memory_resource() - * Warning will be printed if there is collision. - */ - if (err && (err != -EEXIST)) + 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; - err = 0; cond_resched(); } vmemmap_populate_print_last(); -out: return err; } -#ifdef CONFIG_MEMORY_HOTREMOVE /* 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) { - struct mem_section *ms; - - for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) { - ms = __pfn_to_section(start_pfn); - - if (unlikely(!valid_section(ms))) + 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 && zone != page_zone(pfn_to_page(start_pfn))) + if (zone != page_zone(pfn_to_page(start_pfn))) continue; return start_pfn; @@ -345,21 +456,18 @@ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, unsigned long start_pfn, unsigned long end_pfn) { - struct mem_section *ms; unsigned long pfn; /* pfn is the end pfn of a memory section. */ pfn = end_pfn - 1; - for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) { - ms = __pfn_to_section(pfn); - - if (unlikely(!valid_section(ms))) + 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 && zone != page_zone(pfn_to_page(pfn))) + if (zone != page_zone(pfn_to_page(pfn))) continue; return pfn; @@ -371,15 +479,10 @@ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, unsigned long end_pfn) { - unsigned long zone_start_pfn = zone->zone_start_pfn; - unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */ - unsigned long zone_end_pfn = z; unsigned long pfn; - struct mem_section *ms; int nid = zone_to_nid(zone); - zone_span_writelock(zone); - if (zone_start_pfn == start_pfn) { + 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. @@ -387,159 +490,98 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, * for shrinking zone. */ pfn = find_smallest_section_pfn(nid, zone, end_pfn, - zone_end_pfn); + zone_end_pfn(zone)); if (pfn) { + zone->spanned_pages = zone_end_pfn(zone) - pfn; zone->zone_start_pfn = pfn; - zone->spanned_pages = zone_end_pfn - pfn; + } else { + zone->zone_start_pfn = 0; + zone->spanned_pages = 0; } - } else if (zone_end_pfn == end_pfn) { + } 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_start_pfn, + pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn, start_pfn); if (pfn) - zone->spanned_pages = pfn - zone_start_pfn + 1; + zone->spanned_pages = pfn - zone->zone_start_pfn + 1; + else { + zone->zone_start_pfn = 0; + zone->spanned_pages = 0; + } } +} - /* - * The section is not biggest or smallest mem_section in the zone, it - * only creates a hole in the zone. So in this case, we need not - * change the zone. But perhaps, the zone has only hole data. Thus - * it check the zone has only hole or not. - */ - pfn = zone_start_pfn; - for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) { - ms = __pfn_to_section(pfn); +static void update_pgdat_span(struct pglist_data *pgdat) +{ + unsigned long node_start_pfn = 0, node_end_pfn = 0; + struct zone *zone; - if (unlikely(!valid_section(ms))) - continue; + for (zone = pgdat->node_zones; + zone < pgdat->node_zones + MAX_NR_ZONES; zone++) { + unsigned long end_pfn = zone_end_pfn(zone); - if (page_zone(pfn_to_page(pfn)) != zone) + /* No need to lock the zones, they can't change. */ + if (!zone->spanned_pages) continue; - - /* If the section is current section, it continues the loop */ - if (start_pfn == pfn) + if (!node_end_pfn) { + node_start_pfn = zone->zone_start_pfn; + node_end_pfn = end_pfn; continue; + } - /* If we find valid section, we have nothing to do */ - zone_span_writeunlock(zone); - return; + 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; } - /* The zone has no valid section */ - zone->zone_start_pfn = 0; - zone->spanned_pages = 0; - zone_span_writeunlock(zone); + pgdat->node_start_pfn = node_start_pfn; + pgdat->node_spanned_pages = node_end_pfn - node_start_pfn; } -static void shrink_pgdat_span(struct pglist_data *pgdat, - unsigned long start_pfn, unsigned long end_pfn) +void remove_pfn_range_from_zone(struct zone *zone, + unsigned long start_pfn, + unsigned long nr_pages) { - unsigned long pgdat_start_pfn = pgdat->node_start_pfn; - unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */ - unsigned long pgdat_end_pfn = p; - unsigned long pfn; - struct mem_section *ms; - int nid = pgdat->node_id; + const unsigned long end_pfn = start_pfn + nr_pages; + struct pglist_data *pgdat = zone->zone_pgdat; + unsigned long pfn, cur_nr_pages; - if (pgdat_start_pfn == start_pfn) { - /* - * If the section is smallest section in the pgdat, it need - * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages. - * In this case, we find second smallest valid mem_section - * for shrinking zone. - */ - pfn = find_smallest_section_pfn(nid, NULL, end_pfn, - pgdat_end_pfn); - if (pfn) { - pgdat->node_start_pfn = pfn; - pgdat->node_spanned_pages = pgdat_end_pfn - pfn; - } - } else if (pgdat_end_pfn == end_pfn) { - /* - * If the section is biggest section in the pgdat, it need - * shrink pgdat->node_spanned_pages. - * In this case, we find second biggest valid mem_section for - * shrinking zone. - */ - pfn = find_biggest_section_pfn(nid, NULL, pgdat_start_pfn, - start_pfn); - if (pfn) - pgdat->node_spanned_pages = pfn - pgdat_start_pfn + 1; + /* 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); } /* - * If the section is not biggest or smallest mem_section in the pgdat, - * it only creates a hole in the pgdat. So in this case, we need not - * change the pgdat. - * But perhaps, the pgdat has only hole data. Thus it check the pgdat - * has only hole or not. + * 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. */ - pfn = pgdat_start_pfn; - for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) { - ms = __pfn_to_section(pfn); - - if (unlikely(!valid_section(ms))) - continue; - - if (pfn_to_nid(pfn) != nid) - continue; - - /* If the section is current section, it continues the loop */ - if (start_pfn == pfn) - continue; - - /* If we find valid section, we have nothing to do */ + if (zone_is_zone_device(zone)) return; - } - - /* The pgdat has no valid section */ - pgdat->node_start_pfn = 0; - pgdat->node_spanned_pages = 0; -} -static void __remove_zone(struct zone *zone, unsigned long start_pfn) -{ - struct pglist_data *pgdat = zone->zone_pgdat; - int nr_pages = PAGES_PER_SECTION; - unsigned long flags; + clear_zone_contiguous(zone); - pgdat_resize_lock(zone->zone_pgdat, &flags); shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); - shrink_pgdat_span(pgdat, start_pfn, start_pfn + nr_pages); - pgdat_resize_unlock(zone->zone_pgdat, &flags); -} - -static int __remove_section(struct zone *zone, struct mem_section *ms, - unsigned long map_offset, struct vmem_altmap *altmap) -{ - unsigned long start_pfn; - int scn_nr; - int ret = -EINVAL; - - if (!valid_section(ms)) - return ret; + update_pgdat_span(pgdat); - ret = unregister_memory_section(ms); - if (ret) - return ret; - - scn_nr = __section_nr(ms); - start_pfn = section_nr_to_pfn((unsigned long)scn_nr); - __remove_zone(zone, start_pfn); - - sparse_remove_one_section(zone, ms, map_offset, altmap); - return 0; + set_zone_contiguous(zone); } /** - * __remove_pages() - remove sections of pages from a zone - * @zone: zone from which pages need to be removed - * @phys_start_pfn: starting pageframe (must be aligned to start of a section) + * __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 * @@ -548,58 +590,25 @@ static int __remove_section(struct zone *zone, struct mem_section *ms, * sure that pages are marked reserved and zones are adjust properly by * calling offline_pages(). */ -int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, - unsigned long nr_pages, struct vmem_altmap *altmap) +void __remove_pages(unsigned long pfn, unsigned long nr_pages, + struct vmem_altmap *altmap) { - unsigned long i; - unsigned long map_offset = 0; - int sections_to_remove, ret = 0; + const unsigned long end_pfn = pfn + nr_pages; + unsigned long cur_nr_pages; - /* In the ZONE_DEVICE case device driver owns the memory region */ - if (is_dev_zone(zone)) { - if (altmap) - map_offset = vmem_altmap_offset(altmap); - } else { - resource_size_t start, size; - - start = phys_start_pfn << PAGE_SHIFT; - size = nr_pages * PAGE_SIZE; - - ret = release_mem_region_adjustable(&iomem_resource, start, - size); - if (ret) { - resource_size_t endres = start + size - 1; - - pr_warn("Unable to release resource <%pa-%pa> (%d)\n", - &start, &endres, ret); - } + if (check_pfn_span(pfn, nr_pages)) { + WARN(1, "Misaligned %s start: %#lx end: %#lx\n", __func__, pfn, pfn + nr_pages - 1); + return; } - clear_zone_contiguous(zone); - - /* - * We can only remove entire sections - */ - BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK); - BUG_ON(nr_pages % PAGES_PER_SECTION); - - sections_to_remove = nr_pages / PAGES_PER_SECTION; - for (i = 0; i < sections_to_remove; i++) { - unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION; - + for (; pfn < end_pfn; pfn += cur_nr_pages) { cond_resched(); - ret = __remove_section(zone, __pfn_to_section(pfn), map_offset, - altmap); - map_offset = 0; - if (ret) - break; + /* 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); } - - set_zone_contiguous(zone); - - return ret; } -#endif /* CONFIG_MEMORY_HOTREMOVE */ int set_online_page_callback(online_page_callback_t callback) { @@ -639,80 +648,56 @@ int restore_online_page_callback(online_page_callback_t callback) } EXPORT_SYMBOL_GPL(restore_online_page_callback); -void __online_page_set_limits(struct page *page) -{ -} -EXPORT_SYMBOL_GPL(__online_page_set_limits); - -void __online_page_increment_counters(struct page *page) -{ - adjust_managed_page_count(page, 1); -} -EXPORT_SYMBOL_GPL(__online_page_increment_counters); - -void __online_page_free(struct page *page) -{ - __free_reserved_page(page); -} -EXPORT_SYMBOL_GPL(__online_page_free); - -static void generic_online_page(struct page *page) +/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ +void generic_online_page(struct page *page, unsigned int order) { - __online_page_set_limits(page); - __online_page_increment_counters(page); - __online_page_free(page); + __free_pages_core(page, order, MEMINIT_HOTPLUG); } +EXPORT_SYMBOL_GPL(generic_online_page); -static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, - void *arg) +static void online_pages_range(unsigned long start_pfn, unsigned long nr_pages) { - unsigned long i; - unsigned long onlined_pages = *(unsigned long *)arg; - struct page *page; - - if (PageReserved(pfn_to_page(start_pfn))) - for (i = 0; i < nr_pages; i++) { - page = pfn_to_page(start_pfn + i); - (*online_page_callback)(page); - onlined_pages++; - } - - online_mem_sections(start_pfn, start_pfn + nr_pages); - - *(unsigned long *)arg = onlined_pages; - return 0; -} - -/* 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); + const unsigned long end_pfn = start_pfn + nr_pages; + unsigned long pfn; - arg->status_change_nid = -1; - arg->status_change_nid_normal = -1; - arg->status_change_nid_high = -1; - - 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; -#ifdef CONFIG_HIGHMEM - if (zone_idx(zone) <= N_HIGH_MEMORY && !node_state(nid, N_HIGH_MEMORY)) - arg->status_change_nid_high = nid; -#endif -} + /* + * 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;) { + struct page *page = pfn_to_page(pfn); + int order; -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); + /* + * 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; - if (arg->status_change_nid_high >= 0) - node_set_state(node, N_HIGH_MEMORY); + /* + * Exposing the page to the buddy by freeing can cause + * issues with debug_pagealloc enabled: some archs don't + * like double-unmappings. So treat them like any pages that + * were allocated from the buddy. + */ + debug_pagealloc_map_pages(page, 1 << order); + (*online_page_callback)(page, order); + pfn += (1UL << order); + } - if (arg->status_change_nid >= 0) - node_set_state(node, N_MEMORY); + /* mark all involved sections as online */ + online_mem_sections(start_pfn, end_pfn); } static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn, @@ -735,39 +720,176 @@ static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned lon pgdat->node_start_pfn = start_pfn; pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn; + } -void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, - unsigned long nr_pages, struct vmem_altmap *altmap) +#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 move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, + unsigned long nr_pages, + struct vmem_altmap *altmap, int migratetype, + bool isolate_pageblock) { struct pglist_data *pgdat = zone->zone_pgdat; int nid = pgdat->node_id; - unsigned long flags; clear_zone_contiguous(zone); - /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */ - pgdat_resize_lock(pgdat, &flags); - zone_span_writelock(zone); if (zone_is_empty(zone)) init_currently_empty_zone(zone, start_pfn, nr_pages); resize_zone_range(zone, start_pfn, nr_pages); - zone_span_writeunlock(zone); resize_pgdat_range(pgdat, start_pfn, nr_pages); - pgdat_resize_unlock(pgdat, &flags); + + /* + * 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 + * with their zone properly. Not nice but set_pfnblock_migratetype() * 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_zone(nr_pages, nid, zone_idx(zone), start_pfn, - MEMMAP_HOTPLUG, altmap); + memmap_init_range(nr_pages, nid, zone_idx(zone), start_pfn, 0, + MEMINIT_HOTPLUG, altmap, migratetype, + isolate_pageblock); 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 @@ -779,7 +901,7 @@ static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn struct pglist_data *pgdat = NODE_DATA(nid); int zid; - for (zid = 0; zid <= ZONE_NORMAL; zid++) { + for (zid = 0; zid < ZONE_NORMAL; zid++) { struct zone *zone = &pgdat->node_zones[zid]; if (zone_intersects(zone, start_pfn, nr_pages)) @@ -789,6 +911,117 @@ static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn 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, especially + * 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) { @@ -813,7 +1046,8 @@ static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn return movable_node_enabled ? movable_zone : kernel_zone; } -struct zone * zone_for_pfn_range(int online_type, int nid, unsigned start_pfn, +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) @@ -822,56 +1056,145 @@ struct zone * zone_for_pfn_range(int online_type, int nid, unsigned start_pfn, 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); } /* - * Associates the given pfn range with the given node and the zone appropriate - * for the given online type. + * This function should only be called by memory_block_{online,offline}, + * and {online,offline}_pages. */ -static struct zone * __meminit move_pfn_range(int online_type, int nid, - unsigned long start_pfn, unsigned long nr_pages) +void adjust_present_page_count(struct page *page, struct memory_group *group, + long nr_pages) { - struct zone *zone; + 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; - zone = zone_for_pfn_range(online_type, nid, start_pfn, nr_pages); - move_pfn_range_to_zone(zone, start_pfn, nr_pages, NULL); - return zone; + if (group && movable) + group->present_movable_pages += nr_pages; + else if (group && !movable) + group->present_kernel_pages += nr_pages; } -int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type) +int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages, + struct zone *zone) { - unsigned long flags; - unsigned long onlined_pages = 0; - struct zone *zone; + 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; + + move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_UNMOVABLE, + false); + + 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 online_pages(unsigned long pfn, unsigned long nr_pages, + struct zone *zone, struct memory_group *group) +{ + struct memory_notify mem_arg = { + .start_pfn = pfn, + .nr_pages = nr_pages, + }; + struct node_notify node_arg = { + .nid = NUMA_NO_NODE, + }; + const int nid = zone_to_nid(zone); int need_zonelists_rebuild = 0; - int nid; + unsigned long flags; int ret; - struct memory_notify arg; - struct memory_block *mem; - - mem_hotplug_begin(); /* - * We can't use pfn_to_nid() because nid might be stored in struct page - * which is not yet initialized. Instead, we find nid from memory block. + * {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. */ - mem = find_memory_block(__pfn_to_section(pfn)); - nid = mem->nid; + 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 */ - zone = move_pfn_range(online_type, nid, pfn, nr_pages); - arg.start_pfn = pfn; - arg.nr_pages = nr_pages; - node_states_check_changes_online(nr_pages, zone, &arg); + /* associate pfn range with the zone */ + move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_MOVABLE, + true); + + if (!node_state(nid, N_MEMORY)) { + /* Adding memory to the node for the first time */ + node_arg.nid = nid; + ret = node_notify(NODE_ADDING_FIRST_MEMORY, &node_arg); + ret = notifier_to_errno(ret); + if (ret) + goto failed_addition; + } - ret = memory_notify(MEM_GOING_ONLINE, &arg); + ret = memory_notify(MEM_GOING_ONLINE, &mem_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. @@ -881,96 +1204,66 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ setup_zone_pageset(zone); } - ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, - online_pages_range); - if (ret) { - if (need_zonelists_rebuild) - zone_pcp_reset(zone); - goto failed_addition; - } + online_pages_range(pfn, nr_pages); + adjust_present_page_count(pfn_to_page(pfn), group, nr_pages); - zone->present_pages += onlined_pages; + if (node_arg.nid >= 0) + node_set_state(nid, N_MEMORY); + if (need_zonelists_rebuild) + build_all_zonelists(NULL); - pgdat_resize_lock(zone->zone_pgdat, &flags); - zone->zone_pgdat->node_present_pages += onlined_pages; - pgdat_resize_unlock(zone->zone_pgdat, &flags); + /* Basic onlining is complete, allow allocation of onlined pages. */ + undo_isolate_page_range(pfn, pfn + nr_pages); - if (onlined_pages) { - node_states_set_node(nid, &arg); - if (need_zonelists_rebuild) - build_all_zonelists(NULL); - else - zone_pcp_update(zone); - } + /* + * 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(); - if (onlined_pages) { - kswapd_run(nid); - kcompactd_run(nid); - } + kswapd_run(nid); + kcompactd_run(nid); - vm_total_pages = nr_free_pagecache_pages(); + if (node_arg.nid >= 0) + /* First memory added successfully. Notify consumers. */ + node_notify(NODE_ADDED_FIRST_MEMORY, &node_arg); writeback_set_ratelimit(); - if (onlined_pages) - memory_notify(MEM_ONLINE, &arg); - mem_hotplug_done(); + memory_notify(MEM_ONLINE, &mem_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); - mem_hotplug_done(); + memory_notify(MEM_CANCEL_ONLINE, &mem_arg); + if (node_arg.nid != NUMA_NO_NODE) + node_notify(NODE_CANCEL_ADDING_FIRST_MEMORY, &node_arg); + remove_pfn_range_from_zone(zone, pfn, nr_pages); return ret; } -#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ - -static void reset_node_present_pages(pg_data_t *pgdat) -{ - struct zone *z; - - for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++) - z->present_pages = 0; - - pgdat->node_present_pages = 0; -} /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ -static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) +static pg_data_t *hotadd_init_pgdat(int nid) { struct pglist_data *pgdat; - unsigned long start_pfn = PFN_DOWN(start); + /* + * 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); - if (!pgdat) { - pgdat = arch_alloc_nodedata(nid); - if (!pgdat) - return NULL; - - arch_refresh_nodedata(nid, pgdat); - } else { - /* - * Reset the nr_zones, order and classzone_idx before reuse. - * Note that kswapd will init kswapd_classzone_idx properly - * when it starts in the near future. - */ - pgdat->nr_zones = 0; - pgdat->kswapd_order = 0; - pgdat->kswapd_classzone_idx = 0; - } - - /* we can use NODE_DATA(nid) from here */ - - pgdat->node_id = nid; - pgdat->node_start_pfn = start_pfn; /* init node's zones as empty zones, we don't have any present pages.*/ - free_area_init_core_hotplug(nid); - pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat); + free_area_init_core_hotplug(pgdat); /* * The node we allocated has no zone fallback lists. For avoiding @@ -978,32 +1271,12 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) */ build_all_zonelists(pgdat); - /* - * When memory is hot-added, all the memory is in offline state. So - * clear all zones' present_pages because they will be updated in - * online_pages() and offline_pages(). - */ - reset_node_managed_pages(pgdat); - reset_node_present_pages(pgdat); - return pgdat; } -static void rollback_node_hotadd(int nid) -{ - pg_data_t *pgdat = NODE_DATA(nid); - - arch_refresh_nodedata(nid, NULL); - free_percpu(pgdat->per_cpu_nodestats); - arch_free_nodedata(pgdat); - return; -} - - -/** - * try_online_node - online a node if offlined +/* + * __try_online_node - online a node if offlined * @nid: the node ID - * @start: start addr of the node * @set_node_online: Whether we want to online the node * called by cpu_up() to online a node without onlined memory. * @@ -1012,7 +1285,7 @@ static void rollback_node_hotadd(int nid) * 0 -> the node is already online * -ENOMEM -> the node could not be allocated */ -static int __try_online_node(int nid, u64 start, bool set_node_online) +static int __try_online_node(int nid, bool set_node_online) { pg_data_t *pgdat; int ret = 1; @@ -1020,7 +1293,7 @@ static int __try_online_node(int nid, u64 start, bool set_node_online) if (node_online(nid)) return 0; - pgdat = hotadd_new_pgdat(nid, start); + pgdat = hotadd_init_pgdat(nid); if (!pgdat) { pr_err("Cannot online node %d due to NULL pgdat\n", nid); ret = -ENOMEM; @@ -1029,7 +1302,7 @@ static int __try_online_node(int nid, u64 start, bool set_node_online) if (set_node_online) { node_set_online(nid); - ret = register_one_node(nid); + ret = register_node(nid); BUG_ON(ret); } out: @@ -1044,23 +1317,18 @@ int try_online_node(int nid) int ret; mem_hotplug_begin(); - ret = __try_online_node(nid, 0, true); + ret = __try_online_node(nid, true); mem_hotplug_done(); return ret; } static int check_hotplug_memory_range(u64 start, u64 size) { - unsigned long block_sz = memory_block_size_bytes(); - u64 block_nr_pages = block_sz >> PAGE_SHIFT; - u64 nr_pages = size >> PAGE_SHIFT; - u64 start_pfn = PFN_DOWN(start); - /* memory range must be block size aligned */ - if (!nr_pages || !IS_ALIGNED(start_pfn, block_nr_pages) || - !IS_ALIGNED(nr_pages, block_nr_pages)) { + 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", - block_sz, start, size); + memory_block_size_bytes(), start, size); return -EINVAL; } @@ -1069,17 +1337,162 @@ static int check_hotplug_memory_range(u64 start, u64 size) static int online_memory_block(struct memory_block *mem, void *arg) { + mem->online_type = mhp_get_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 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) +{ + 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(); + 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, nid, + 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) +int 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; @@ -1091,516 +1504,481 @@ int __ref add_memory_resource(int nid, struct resource *res) 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(); - /* - * Add new range to memblock so that when hotadd_new_pgdat() is called - * to allocate new pgdat, get_pfn_range_for_nid() will be able to find - * this new range and calculate total pages correctly. The range will - * be removed at hot-remove time. - */ - memblock_add_node(start, size, nid); + 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, start, false); + ret = __try_online_node(nid, false); if (ret < 0) - goto error; - new_node = ret; + goto error_memblock_remove; + if (ret) { + node_set_online(nid); + ret = register_node(nid); + if (WARN_ON(ret)) { + node_set_offline(nid); + goto error_memblock_remove; + } + new_node = true; + } - /* call arch's memory hotadd */ - ret = arch_add_memory(nid, start, size, NULL, true); - if (ret < 0) - goto error; + /* + * 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); + if (ret) + goto error; + } else { + ret = arch_add_memory(nid, start, size, ¶ms); + if (ret < 0) + 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); + /* create memory block devices after memory was added */ + ret = create_memory_block_devices(start, size, nid, NULL, group); + if (ret) { + arch_remove_memory(start, size, params.altmap); + goto error; + } } - /* link memory sections under this node.*/ - ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1)); - BUG_ON(ret); + register_memory_blocks_under_node_hotplug(nid, PFN_DOWN(start), + PFN_UP(start + size - 1)); /* create new memmap entry */ - firmware_map_add_hotplug(start, start + size, "System RAM"); + 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 (memhp_auto_online) - walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), - NULL, online_memory_block); + if (mhp_get_default_online_type() != MMOP_OFFLINE) + walk_memory_blocks(start, size, NULL, online_memory_block); return ret; error: - /* rollback pgdat allocation and others */ - if (new_node) - rollback_node_hotadd(nid); - memblock_remove(start, size); + if (new_node) { + node_set_offline(nid); + unregister_node(nid); + } +error_memblock_remove: + 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) +int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) { struct resource *res; int ret; - res = register_memory_resource(start, size); + res = register_memory_resource(start, size, "System RAM"); if (IS_ERR(res)) return PTR_ERR(res); - ret = add_memory_resource(nid, 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) +int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) { int rc; lock_device_hotplug(); - rc = __add_memory(nid, start, size); + rc = __add_memory(nid, start, size, mhp_flags); unlock_device_hotplug(); return rc; } EXPORT_SYMBOL_GPL(add_memory); -#ifdef CONFIG_MEMORY_HOTREMOVE /* - * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy - * set and the size of the free page is given by page_order(). Using this, - * the function determines if the pageblock contains only free pages. - * Due to buddy contraints, a free page at least the size of a pageblock will - * be located at the start of the pageblock + * 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)". */ -static inline int pageblock_free(struct page *page) +int add_memory_driver_managed(int nid, u64 start, u64 size, + const char *resource_name, mhp_t mhp_flags) { - return PageBuddy(page) && page_order(page) >= pageblock_order; -} + struct resource *res; + int rc; -/* Return the start of the next active pageblock after a given page */ -static struct page *next_active_pageblock(struct page *page) -{ - /* Ensure the starting page is pageblock-aligned */ - BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1)); + if (!resource_name || + strstr(resource_name, "System RAM (") != resource_name || + resource_name[strlen(resource_name) - 1] != ')') + return -EINVAL; - /* If the entire pageblock is free, move to the end of free page */ - if (pageblock_free(page)) { - int order; - /* be careful. we don't have locks, page_order can be changed.*/ - order = page_order(page); - if ((order < MAX_ORDER) && (order >= pageblock_order)) - return page + (1 << order); + lock_device_hotplug(); + + res = register_memory_resource(start, size, resource_name); + if (IS_ERR(res)) { + rc = PTR_ERR(res); + goto out_unlock; } - return page + pageblock_nr_pages; + 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); -static bool is_pageblock_removable_nolock(struct page *page) +/* + * 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 zone *zone; - unsigned long pfn; - - /* - * We have to be careful here because we are iterating over memory - * sections which are not zone aware so we might end up outside of - * the zone but still within the section. - * We have to take care about the node as well. If the node is offline - * its NODE_DATA will be NULL - see page_zone. - */ - if (!node_online(page_to_nid(page))) - return false; - - zone = page_zone(page); - pfn = page_to_pfn(page); - if (!zone_spans_pfn(zone, pfn)) - return false; - - return !has_unmovable_pages(zone, page, 0, MIGRATE_MOVABLE, SKIP_HWPOISON); + struct range mhp_range = { + .start = 0UL, + .end = -1ULL, + }; + return mhp_range; } -/* Checks if this range of memory is likely to be hot-removable. */ -bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) +struct range mhp_get_pluggable_range(bool need_mapping) { - struct page *page = pfn_to_page(start_pfn); - struct page *end_page = page + nr_pages; + const u64 max_phys = DIRECT_MAP_PHYSMEM_END; + struct range mhp_range; - /* Check the starting page of each pageblock within the range */ - for (; page < end_page; page = next_active_pageblock(page)) { - if (!is_pageblock_removable_nolock(page)) - return false; - cond_resched(); + 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; } - - /* All pageblocks in the memory block are likely to be hot-removable */ - return true; + return mhp_range; } +EXPORT_SYMBOL_GPL(mhp_get_pluggable_range); -/* - * Confirm all pages in a range [start, end) belong to the same zone. - * When true, return its valid [start, end). - */ -int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn, - unsigned long *valid_start, unsigned long *valid_end) +bool mhp_range_allowed(u64 start, u64 size, bool need_mapping) { - unsigned long pfn, sec_end_pfn; - unsigned long start, end; - struct zone *zone = NULL; - struct page *page; - int i; - for (pfn = start_pfn, sec_end_pfn = SECTION_ALIGN_UP(start_pfn + 1); - pfn < end_pfn; - pfn = sec_end_pfn, sec_end_pfn += PAGES_PER_SECTION) { - /* Make sure the memory section is present first */ - if (!present_section_nr(pfn_to_section_nr(pfn))) - continue; - for (; pfn < sec_end_pfn && pfn < end_pfn; - pfn += MAX_ORDER_NR_PAGES) { - i = 0; - /* This is just a CONFIG_HOLES_IN_ZONE check.*/ - while ((i < MAX_ORDER_NR_PAGES) && - !pfn_valid_within(pfn + i)) - i++; - if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn) - continue; - page = pfn_to_page(pfn + i); - if (zone && page_zone(page) != zone) - return 0; - if (!zone) - start = pfn + i; - zone = page_zone(page); - end = pfn + MAX_ORDER_NR_PAGES; - } - } + struct range mhp_range = mhp_get_pluggable_range(need_mapping); + u64 end = start + size; - if (zone) { - *valid_start = start; - *valid_end = min(end, end_pfn); - return 1; - } else { - return 0; - } + 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). We scan pfn because it's much - * easier than scanning over linked list. This function returns the pfn - * of the first found movable page if it's found, otherwise 0. + * Scan pfn range [start,end) to find movable/migratable pages (LRU and + * hugetlb folio, movable_ops pages). 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 unsigned long scan_movable_pages(unsigned long start, unsigned long end) +static int scan_movable_pages(unsigned long start, unsigned long end, + unsigned long *movable_pfn) { unsigned long pfn; - struct page *page; - for (pfn = start; pfn < end; pfn++) { - if (pfn_valid(pfn)) { - page = pfn_to_page(pfn); - if (PageLRU(page)) - return pfn; - if (__PageMovable(page)) - return pfn; - if (PageHuge(page)) { - if (hugepage_migration_supported(page_hstate(page)) && - page_huge_active(page)) - return pfn; - else - pfn = round_up(pfn + 1, - 1 << compound_order(page)) - 1; - } - } - } - return 0; -} -static struct page *new_node_page(struct page *page, unsigned long private) -{ - int nid = page_to_nid(page); - nodemask_t nmask = node_states[N_MEMORY]; + for_each_valid_pfn(pfn, start, end) { + struct page *page; + struct folio *folio; - /* - * 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(nid, nmask); - if (nodes_empty(nmask)) - node_set(nid, nmask); + page = pfn_to_page(pfn); + if (PageLRU(page) || page_has_movable_ops(page)) + goto found; + + /* + * PageOffline() pages that do not have movable_ops 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; - return new_page_nodemask(page, nid, &nmask); + 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 int -do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) +static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) { + struct folio *folio; unsigned long pfn; - struct page *page; - int not_managed = 0; - int ret = 0; LIST_HEAD(source); + static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + + for_each_valid_pfn(pfn, start_pfn, end_pfn) { + struct page *page; - for (pfn = start_pfn; pfn < end_pfn; pfn++) { - if (!pfn_valid(pfn)) - continue; page = pfn_to_page(pfn); + folio = page_folio(page); - if (PageHuge(page)) { - struct page *head = compound_head(page); - pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1; - if (compound_order(head) > PFN_SECTION_SHIFT) { - ret = -EBUSY; - break; - } - isolate_huge_page(page, &source); + if (!folio_try_get(folio)) continue; - } else if (PageTransHuge(page)) - pfn = page_to_pfn(compound_head(page)) - + hpage_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(PageLRU(page))) - isolate_lru_page(page); - if (page_mapped(page)) - try_to_unmap(page, TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS); - continue; - } + if (unlikely(page_folio(page) != folio)) + goto put_folio; - 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)) - ret = isolate_lru_page(page); - else - ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); - if (!ret) { /* Success */ - put_page(page); - list_add_tail(&page->lru, &source); - if (!__PageMovable(page)) - inc_node_page_state(page, NR_ISOLATED_ANON + - page_is_file_cache(page)); + if (folio_test_large(folio)) + pfn = folio_pfn(folio) + folio_nr_pages(folio) - 1; - } else { - pr_warn("failed to isolate pfn %lx\n", pfn); - dump_page(page, "isolation failed"); - put_page(page); - /* Because we don't have big zone->lock. we should - check this again here. */ - if (page_count(page)) { - not_managed++; - ret = -EBUSY; - break; + if (folio_contain_hwpoisoned_page(folio)) { + /* + * unmap_poisoned_folio() cannot handle large folios + * in all cases yet. + */ + if (folio_test_large(folio) && !folio_test_hugetlb(folio)) + goto put_folio; + if (folio_test_lru(folio) && !folio_isolate_lru(folio)) + goto put_folio; + if (folio_mapped(folio)) { + folio_lock(folio); + unmap_poisoned_folio(folio, pfn, false); + folio_unlock(folio); + } + + goto put_folio; + } + + if (!isolate_folio_to_list(folio, &source)) { + if (__ratelimit(&migrate_rs)) { + pr_warn("failed to isolate pfn %lx\n", + page_to_pfn(page)); + dump_page(page, "isolation failed"); } } +put_folio: + folio_put(folio); } if (!list_empty(&source)) { - if (not_managed) { - putback_movable_pages(&source); - goto out; - } + nodemask_t nmask = node_states[N_MEMORY]; + struct migration_target_control mtc = { + .nmask = &nmask, + .gfp_mask = GFP_KERNEL | __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 = folio_nid(list_first_entry(&source, struct folio, lru)); - /* Allocate a new page from the nearest neighbor node */ - ret = migrate_pages(&source, new_node_page, NULL, 0, - MIGRATE_SYNC, MR_MEMORY_HOTPLUG); + /* + * 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) { - pr_warn("migrating pfn %lx failed ret:%d ", - page_to_pfn(page), ret); - dump_page(page, "migration failure"); + list_for_each_entry(folio, &source, lru) { + if (__ratelimit(&migrate_rs)) { + pr_warn("migrating pfn %lx failed ret:%d\n", + folio_pfn(folio), ret); + dump_page(&folio->page, + "migration failure"); + } } putback_movable_pages(&source); } } -out: - return ret; } -/* - * remove from free_area[] and mark all as Reserved. - */ -static int -offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, - void *data) +static int __init cmdline_parse_movable_node(char *p) { - __offline_isolated_pages(start, start + nr_pages); + movable_node_enabled = true; return 0; } +early_param("movable_node", cmdline_parse_movable_node); -static void -offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) -{ - walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL, - offline_isolated_pages_cb); -} - -/* - * Check all pages in range, recoreded as memory resource, are isolated. - */ -static int -check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages, - void *data) -{ - int ret; - long offlined = *(long *)data; - ret = test_pages_isolated(start_pfn, start_pfn + nr_pages, true); - offlined = nr_pages; - if (!ret) - *(long *)data += offlined; - return ret; -} - -static long -check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) +static int count_system_ram_pages_cb(unsigned long start_pfn, + unsigned long nr_pages, void *data) { - long offlined = 0; - int ret; - - ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined, - check_pages_isolated_cb); - if (ret < 0) - offlined = (long)ret; - return offlined; -} + unsigned long *nr_system_ram_pages = data; -static int __init cmdline_parse_movable_node(char *p) -{ -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP - movable_node_enabled = true; -#else - pr_warn("movable_node parameter depends on CONFIG_HAVE_MEMBLOCK_NODE_MAP to work properly\n"); -#endif + *nr_system_ram_pages += nr_pages; 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) +/* + * Must be called with mem_hotplug_lock in write mode. + */ +int offline_pages(unsigned long start_pfn, unsigned long nr_pages, + struct zone *zone, struct memory_group *group) { + unsigned long pfn, managed_pages, system_ram_pages = 0; + const unsigned long end_pfn = start_pfn + nr_pages; struct pglist_data *pgdat = zone->zone_pgdat; - unsigned long present_pages = 0; - enum zone_type zt; - - arg->status_change_nid = -1; - arg->status_change_nid_normal = -1; - arg->status_change_nid_high = -1; + const int node = zone_to_nid(zone); + struct memory_notify mem_arg = { + .start_pfn = start_pfn, + .nr_pages = nr_pages, + }; + struct node_notify node_arg = { + .nid = NUMA_NO_NODE, + }; + unsigned long flags; + char *reason; + int ret; /* - * 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]. + * {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. */ - 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); + if (WARN_ON_ONCE(!nr_pages || !pageblock_aligned(start_pfn) || + !IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION))) + return -EINVAL; -#ifdef CONFIG_HIGHMEM /* - * node_states[N_HIGH_MEMORY] contains nodes which - * have normal memory or high memory. - * Here we add the present_pages belonging to ZONE_HIGHMEM. - * If the zone is within the range of [0..ZONE_HIGHMEM), and - * we determine that the zones in that range become empty, - * we need to clear the node for N_HIGH_MEMORY. + * 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. */ - present_pages += pgdat->node_zones[ZONE_HIGHMEM].present_pages; - if (zone_idx(zone) <= ZONE_HIGHMEM && nr_pages >= present_pages) - arg->status_change_nid_high = zone_to_nid(zone); -#endif + 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 have accounted the pages from [0..ZONE_NORMAL), and - * in case of CONFIG_HIGHMEM the pages from ZONE_HIGHMEM - * as well. - * 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. + * 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. */ - 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_high >= 0) - node_clear_state(node, N_HIGH_MEMORY); - - if (arg->status_change_nid >= 0) - node_clear_state(node, N_MEMORY); -} - -static int __ref __offline_pages(unsigned long start_pfn, - unsigned long end_pfn) -{ - unsigned long pfn, nr_pages; - long offlined_pages; - int ret, node; - unsigned long flags; - unsigned long valid_start, valid_end; - struct zone *zone; - struct memory_notify arg; - char *reason; - - mem_hotplug_begin(); - - /* This makes hotplug much easier...and readable. - we assume this for now. .*/ - if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start, - &valid_end)) { - mem_hotplug_done(); + 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; } - zone = page_zone(pfn_to_page(valid_start)); - node = zone_to_nid(zone); - nr_pages = end_pfn - start_pfn; + /* + * 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, - SKIP_HWPOISON | REPORT_FAILURE); + PB_ISOLATE_MODE_MEM_OFFLINE); if (ret) { - mem_hotplug_done(); reason = "failure to isolate range"; - goto failed_removal; + goto failed_removal_pcplists_disabled; } - arg.start_pfn = start_pfn; - arg.nr_pages = nr_pages; - node_states_check_changes_offline(nr_pages, zone, &arg); + /* + * Check whether the node will have no present pages after we offline + * 'nr_pages' more. If so, we know that the node will become empty, and + * so we will clear N_MEMORY for it. + */ + if (nr_pages >= pgdat->node_present_pages) { + node_arg.nid = node; + ret = node_notify(NODE_REMOVING_LAST_MEMORY, &node_arg); + ret = notifier_to_errno(ret); + if (ret) { + reason = "node notifier failure"; + goto failed_removal_isolated; + } + } - ret = memory_notify(MEM_GOING_OFFLINE, &arg); + ret = memory_notify(MEM_GOING_OFFLINE, &mem_arg); ret = notifier_to_errno(ret); if (ret) { reason = "notifier failure"; @@ -1608,7 +1986,13 @@ static int __ref __offline_pages(unsigned long start_pfn, } do { - for (pfn = start_pfn; pfn;) { + 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"; @@ -1616,159 +2000,136 @@ static int __ref __offline_pages(unsigned long start_pfn, } cond_resched(); - lru_add_drain_all(); - drain_all_pages(zone); - pfn = scan_movable_pages(pfn, end_pfn); - if (pfn) { + 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 hugepages in the memory block before doing + * Dissolve free hugetlb folios in the memory block before doing * offlining actually in order to make hugetlbfs's object * counting consistent. */ - ret = dissolve_free_huge_pages(start_pfn, end_pfn); + ret = dissolve_free_hugetlb_folios(start_pfn, end_pfn); if (ret) { reason = "failure to dissolve huge pages"; goto failed_removal_isolated; } - /* check again */ - offlined_pages = check_pages_isolated(start_pfn, end_pfn); - } while (offlined_pages < 0); - - pr_info("Offlined Pages %ld\n", offlined_pages); - /* Ok, all of our target is isolated. - We cannot do rollback at this point. */ - offline_isolated_pages(start_pfn, end_pfn); - /* reset pagetype flags and makes migrate type to be MOVABLE */ - undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); - /* removal success */ - adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages); - zone->present_pages -= offlined_pages; - pgdat_resize_lock(zone->zone_pgdat, &flags); - zone->zone_pgdat->node_present_pages -= offlined_pages; - pgdat_resize_unlock(zone->zone_pgdat, &flags); + ret = test_pages_isolated(start_pfn, end_pfn, + PB_ISOLATE_MODE_MEM_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. + */ + if (node_arg.nid >= 0) + node_clear_state(node, N_MEMORY); if (!populated_zone(zone)) { zone_pcp_reset(zone); build_all_zonelists(NULL); - } else - zone_pcp_update(zone); + } - node_states_clear_node(node, &arg); - if (arg.status_change_nid >= 0) { - kswapd_stop(node); + if (node_arg.nid >= 0) { kcompactd_stop(node); + kswapd_stop(node); + /* Node went memoryless. Notify consumers */ + node_notify(NODE_REMOVED_LAST_MEMORY, &node_arg); } - vm_total_pages = nr_free_pagecache_pages(); writeback_set_ratelimit(); - memory_notify(MEM_OFFLINE, &arg); - mem_hotplug_done(); + memory_notify(MEM_OFFLINE, &mem_arg); + remove_pfn_range_from_zone(zone, start_pfn, nr_pages); return 0; failed_removal_isolated: - undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); + /* pushback to free area */ + undo_isolate_page_range(start_pfn, end_pfn); + memory_notify(MEM_CANCEL_OFFLINE, &mem_arg); + if (node_arg.nid != NUMA_NO_NODE) + node_notify(NODE_CANCEL_REMOVING_LAST_MEMORY, &node_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); - memory_notify(MEM_CANCEL_OFFLINE, &arg); - /* pushback to free area */ - mem_hotplug_done(); return ret; } -int offline_pages(unsigned long start_pfn, unsigned long nr_pages) -{ - return __offline_pages(start_pfn, start_pfn + nr_pages); -} -#endif /* CONFIG_MEMORY_HOTREMOVE */ - -/** - * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn) - * @start_pfn: start pfn of the memory range - * @end_pfn: end pfn of the memory range - * @arg: argument passed to func - * @func: callback for each memory section walked - * - * This function walks through all present mem sections in range - * [start_pfn, end_pfn) and call func on each mem section. - * - * Returns the return value of func. - */ -int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, - void *arg, int (*func)(struct memory_block *, void *)) +static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) { - struct memory_block *mem = NULL; - struct mem_section *section; - unsigned long pfn, section_nr; - int ret; + int *nid = arg; - for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { - section_nr = pfn_to_section_nr(pfn); - if (!present_section_nr(section_nr)) - continue; - - section = __nr_to_section(section_nr); - /* same memblock? */ - if (mem) - if ((section_nr >= mem->start_section_nr) && - (section_nr <= mem->end_section_nr)) - continue; + *nid = mem->nid; + if (unlikely(mem->state != MEM_OFFLINE)) { + phys_addr_t beginpa, endpa; - mem = find_memory_block_hinted(section, mem); - if (!mem) - continue; + 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); - ret = func(mem, arg); - if (ret) { - kobject_put(&mem->dev.kobj); - return ret; - } + return -EBUSY; } - - if (mem) - kobject_put(&mem->dev.kobj); - return 0; } -#ifdef CONFIG_MEMORY_HOTREMOVE -static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) +static int count_memory_range_altmaps_cb(struct memory_block *mem, void *arg) { - int ret = !is_memblock_offlined(mem); + u64 *num_altmaps = (u64 *)arg; - if (unlikely(ret)) { - phys_addr_t beginpa, endpa; + if (mem->altmap) + *num_altmaps += 1; - beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); - endpa = PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1))-1; - pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", - &beginpa, &endpa); - } - - return ret; + return 0; } -static int check_cpu_on_node(pg_data_t *pgdat) +static int check_cpu_on_node(int nid) { int cpu; for_each_present_cpu(cpu) { - if (cpu_to_node(cpu) == pgdat->node_id) + if (cpu_to_node(cpu) == nid) /* * the cpu on this node isn't removed, and we can't * offline this node. @@ -1779,6 +2140,18 @@ static int check_cpu_on_node(pg_data_t *pgdat) 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 @@ -1790,28 +2163,26 @@ static int check_cpu_on_node(pg_data_t *pgdat) */ void try_offline_node(int nid) { - pg_data_t *pgdat = NODE_DATA(nid); - unsigned long start_pfn = pgdat->node_start_pfn; - unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages; - unsigned long pfn; - - for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { - unsigned long section_nr = pfn_to_section_nr(pfn); - - if (!present_section_nr(section_nr)) - continue; + int rc; - if (pfn_to_nid(pfn) != nid) - continue; + /* + * 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; - /* - * some memory sections of this node are not removed, and we - * can't offline node now. - */ + /* + * 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(pgdat)) + if (check_cpu_on_node(nid)) return; /* @@ -1819,13 +2190,85 @@ void try_offline_node(int nid) * node now. */ node_set_offline(nid); - unregister_one_node(nid); + unregister_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 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 - * @nid: the node ID + * __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 * @@ -1833,41 +2276,140 @@ EXPORT_SYMBOL(try_offline_node); * and online/offline operations before this call, as required by * try_offline_node(). */ -void __ref __remove_memory(int nid, u64 start, u64 size) +void __remove_memory(u64 start, u64 size) { - int ret; - BUG_ON(check_hotplug_memory_range(start, size)); + /* + * trigger BUG() if some memory is not offlined prior to calling this + * function + */ + if (try_remove_memory(start, size)) + BUG(); +} - mem_hotplug_begin(); +/* + * 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; /* - * All memory blocks must be offlined before removing memory. Check - * whether all memory blocks in question are offline and trigger a BUG() - * if this is not the case. + * 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. */ - ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL, - check_memblock_offlined_cb); - if (ret) - BUG(); + page = pfn_to_online_page(section_nr_to_pfn(mem->start_section_nr)); + if (page && page_zonenum(page) == ZONE_MOVABLE) + online_type = MMOP_ONLINE_MOVABLE; - /* remove memmap entry */ - firmware_map_remove(start, start + size, "System RAM"); - memblock_free(start, size); - memblock_remove(start, size); + 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; - arch_remove_memory(nid, start, size, NULL); + (*online_types)++; + /* Ignore if already offline. */ + return rc < 0 ? rc : 0; +} - try_offline_node(nid); +static int try_reonline_memory_block(struct memory_block *mem, void *arg) +{ + uint8_t **online_types = arg; + int rc; - mem_hotplug_done(); + 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; } -void remove_memory(int nid, u64 start, u64 size) +/* + * 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(); - __remove_memory(nid, start, size); + + 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(remove_memory); +EXPORT_SYMBOL_GPL(offline_and_remove_memory); #endif /* CONFIG_MEMORY_HOTREMOVE */ |