From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A08A34483AA for ; Fri, 24 Jul 2026 16:45:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784911516; cv=none; b=urB3M+SsYzeYZLTHGEOELELdN3szKxS/kiUQM2sdwzeY7HfutjgNy4LIXxRDl0gkHB/VBD/Y/It4q900Mh40pJeTel3KiKuosHsmGsRwn9JAH7pB23aaMb5QfqGIlnd0HvW1ca76YQ/4kNjXv6JVSRS/aV/OGv3iN/Pn2K0Xxs8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784911516; c=relaxed/simple; bh=dnsSR5vEhb0nE8WBS0MavbWIMzg26YG276kTWZqxldo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Xfp2L/kAadCGyQN44QKBcZSbuJn7Jle872Z7tFd46P0gi9pw+DNj/EIhs6WNNyS+Uq8hEUYBzLFH0cB2ke1Pp8fHCn2tn2qoxS23hZX0ynSpQR3lwThkDQDU3OsI6d/GI2ZSaZTT405MpPPomwYftlObNrw4mKvOUcT5aT2Rc4s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oJrhIw/J; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oJrhIw/J" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0DD761F000E9; Fri, 24 Jul 2026 16:45:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784911508; bh=x5JjqeSiHi+bShLu3Kpmb0UH5WA/wnXivpdOaN9oDuM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=oJrhIw/JII1LAxCFHihZiRNYX+eeAXcgCbDJfunCn1UyaQMsfHctVDOmp2OFCOigC bafvaO6d91jgCm7fBikS1VHVGlwEYbELyQe+1ZwPL6b4UNkuylmT8ILOyyh2HHZBhG KOKY+d3rfXQ+V8LT2X9RAJgfY1IFSt0KKlCI/jaRjI5071udGtKAiy0L1rEFjQJuPj UJr6WvzvyPMUG5VfIuAOB8LxoXPH3kZZsx1acfd3IB8IEiYw0zkk8lpuiPGioLjMvv EMh3S44YNxy1h6PPrJjDgofB97G2PhXV4xlI5qeL/ZD1gzQnsntaYsf2PI2Gwt7qle tILHOvNiil01A== From: Sasha Levin To: stable@vger.kernel.org Cc: "David Hildenbrand (Arm)" , "Lorenzo Stoakes (Oracle)" , "Mike Rapoport (Microsoft)" , Axel Rasmussen , Liam Howlett , Michal Hocko , Oscar Salvador , Sidhartha Kumar , Suren Baghdasaryan , Vlastimil Babka , Wei Xu , Yuanchu Xie , Andrew Morton , Sasha Levin Subject: [PATCH 6.18.y 1/2] mm: prepare to move subsection_map_init() to mm/sparse-vmemmap.c Date: Fri, 24 Jul 2026 12:45:04 -0400 Message-ID: <20260724164505.471020-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026072034-plow-sliceable-b741@gregkh> References: <2026072034-plow-sliceable-b741@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "David Hildenbrand (Arm)" [ Upstream commit fead6dcff83b02f8d6dc3c1ebbe4e09c05c54ee5 ] We want to move subsection_map_init() to mm/sparse-vmemmap.c. To prepare for getting rid of subsection_map_init() in mm/sparse.c completely, use a static inline function for !CONFIG_SPARSEMEM_VMEMMAP. While at it, move the declaration to internal.h and rename it to "sparse_init_subsection_map()". Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-11-096addc8800d@kernel.org Signed-off-by: David Hildenbrand (Arm) Reviewed-by: Lorenzo Stoakes (Oracle) Reviewed-by: Mike Rapoport (Microsoft) Cc: Axel Rasmussen Cc: Liam Howlett Cc: Michal Hocko Cc: Oscar Salvador Cc: Sidhartha Kumar Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Wei Xu Cc: Yuanchu Xie Signed-off-by: Andrew Morton Stable-dep-of: 721a73e30c9e ("mm/sparse-vmemmap: fix DAX vmemmap accounting with optimization") Signed-off-by: Sasha Levin --- arch/arm64/mm/mmu.c | 5 +- arch/loongarch/mm/init.c | 5 +- arch/powerpc/mm/mem.c | 5 +- arch/riscv/mm/init.c | 5 +- arch/s390/mm/init.c | 5 +- arch/x86/mm/init_64.c | 5 +- include/linux/memory_hotplug.h | 8 +- include/linux/mmzone.h | 8 +- mm/Kconfig | 2 +- mm/internal.h | 50 ++++ mm/memory_hotplug.c | 13 +- mm/memremap.c | 4 +- mm/mm_init.c | 2 +- mm/sparse-vmemmap.c | 322 +++++++++++++++++++++++++ mm/sparse.c | 428 +-------------------------------- 15 files changed, 410 insertions(+), 457 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index ada93622ccf2c0..04b9a9ca21eb98 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -2031,12 +2031,13 @@ int arch_add_memory(int nid, u64 start, u64 size, return ret; } -void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) +void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap, + struct dev_pagemap *pgmap) { unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; - __remove_pages(start_pfn, nr_pages, altmap); + __remove_pages(start_pfn, nr_pages, altmap, pgmap); __remove_pgd_mapping(swapper_pg_dir, __phys_to_virt(start), size); } diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c index 900ce1da75a436..18c61e7668b767 100644 --- a/arch/loongarch/mm/init.c +++ b/arch/loongarch/mm/init.c @@ -93,12 +93,13 @@ int arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params) return ret; } -void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) +void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap, + struct dev_pagemap *pgmap) { unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; - __remove_pages(start_pfn, nr_pages, altmap); + __remove_pages(start_pfn, nr_pages, altmap, pgmap); } #endif diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 3ddbfdbfa9413a..38909ba62173cc 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -157,12 +157,13 @@ int __ref arch_add_memory(int nid, u64 start, u64 size, return rc; } -void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) +void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap, + struct dev_pagemap *pgmap) { unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; - __remove_pages(start_pfn, nr_pages, altmap); + __remove_pages(start_pfn, nr_pages, altmap, pgmap); arch_remove_linear_mapping(start, size); } #endif diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index ee40ca01ac6636..71c29c5dddb2d3 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1851,9 +1851,10 @@ int __ref arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *param return ret; } -void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) +void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap, + struct dev_pagemap *pgmap) { - __remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT, altmap); + __remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT, altmap, pgmap); remove_linear_mapping(start, size); flush_tlb_all(); } diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index e4953453d25484..e13298e405f22d 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -279,12 +279,13 @@ int arch_add_memory(int nid, u64 start, u64 size, return rc; } -void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) +void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap, + struct dev_pagemap *pgmap) { unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; - __remove_pages(start_pfn, nr_pages, altmap); + __remove_pages(start_pfn, nr_pages, altmap, pgmap); vmem_remove_mapping(start, size); } #endif /* CONFIG_MEMORY_HOTPLUG */ diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 74eda988e0b027..93eae4f9f0f0be 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1307,12 +1307,13 @@ kernel_physical_mapping_remove(unsigned long start, unsigned long end) remove_pagetable(start, end, true, NULL); } -void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) +void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap, + struct dev_pagemap *pgmap) { unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; - __remove_pages(start_pfn, nr_pages, altmap); + __remove_pages(start_pfn, nr_pages, altmap, pgmap); kernel_physical_mapping_remove(start, start + size); } #endif /* CONFIG_MEMORY_HOTPLUG */ diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 23f038a162319a..562f3086ddb264 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -151,9 +151,10 @@ static inline bool movable_node_is_enabled(void) return movable_node_enabled; } -extern void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap); +extern void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap, + struct dev_pagemap *pgmap); extern void __remove_pages(unsigned long start_pfn, unsigned long nr_pages, - struct vmem_altmap *altmap); + struct vmem_altmap *altmap, struct dev_pagemap *pgmap); /* reasonably generic interface to expand the physical pages */ extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages, @@ -323,7 +324,8 @@ extern int sparse_add_section(int nid, unsigned long pfn, unsigned long nr_pages, struct vmem_altmap *altmap, struct dev_pagemap *pgmap); extern void sparse_remove_section(unsigned long pfn, unsigned long nr_pages, - struct vmem_altmap *altmap); + struct vmem_altmap *altmap, + struct dev_pagemap *pgmap); extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum); extern struct zone *zone_for_pfn_range(int online_type, int nid, diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 7fb7331c572507..91434e9de4688a 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1900,15 +1900,13 @@ struct mem_section_usage { unsigned long pageblock_flags[0]; }; -void subsection_map_init(unsigned long pfn, unsigned long nr_pages); - struct page; struct page_ext; struct mem_section { /* * This is, logically, a pointer to an array of struct * pages. However, it is stored with some other magic. - * (see sparse.c::sparse_init_one_section()) + * (see sparse_init_one_section()) * * Additionally during early boot we encode node id of * the location of the section here to guide allocation. @@ -2292,11 +2290,9 @@ static inline unsigned long next_present_section_nr(unsigned long section_nr) void sparse_init(void); #else #define sparse_init() do {} while (0) -#define sparse_index_init(_sec, _nid) do {} while (0) -#define sparse_vmemmap_init_nid_early(_nid, _use) do {} while (0) +#define sparse_vmemmap_init_nid_early(_nid) do {} while (0) #define sparse_vmemmap_init_nid_late(_nid) do {} while (0) #define pfn_in_present_section pfn_valid -#define subsection_map_init(_pfn, _nr_pages) do {} while (0) #endif /* CONFIG_SPARSEMEM */ /* diff --git a/mm/Kconfig b/mm/Kconfig index 76001e9ba04f1c..6c65af51f3a6b5 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -483,7 +483,7 @@ config ARCH_ENABLE_MEMORY_HOTREMOVE menuconfig MEMORY_HOTPLUG bool "Memory hotplug" select MEMORY_ISOLATION - depends on SPARSEMEM + depends on SPARSEMEM_VMEMMAP depends on ARCH_ENABLE_MEMORY_HOTPLUG depends on 64BIT select NUMA_KEEP_MEMINFO if NUMA diff --git a/mm/internal.h b/mm/internal.h index f5c0d927924d0f..33bb281be42a32 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -851,6 +851,56 @@ void memmap_init_range(unsigned long, int, unsigned long, unsigned long, unsigned long, enum meminit_context, struct vmem_altmap *, int, bool); +/* + * mm/sparse.c + */ +#ifdef CONFIG_SPARSEMEM +int sparse_index_init(unsigned long section_nr, int nid); + +static inline void sparse_init_one_section(struct mem_section *ms, + unsigned long pnum, struct page *mem_map, + struct mem_section_usage *usage, unsigned long flags) +{ + unsigned long coded_mem_map; + + BUILD_BUG_ON(SECTION_MAP_LAST_BIT > PFN_SECTION_SHIFT); + + /* + * We encode the start PFN of the section into the mem_map such that + * page_to_pfn() on !CONFIG_SPARSEMEM_VMEMMAP can simply subtract it + * from the page pointer to obtain the PFN. + */ + coded_mem_map = (unsigned long)(mem_map - section_nr_to_pfn(pnum)); + VM_WARN_ON_ONCE(coded_mem_map & ~SECTION_MAP_MASK); + + ms->section_mem_map &= ~SECTION_MAP_MASK; + ms->section_mem_map |= coded_mem_map; + ms->section_mem_map |= flags | SECTION_HAS_MEM_MAP; + ms->usage = usage; +} + +static inline void __section_mark_present(struct mem_section *ms, + unsigned long section_nr) +{ + if (section_nr > __highest_present_section_nr) + __highest_present_section_nr = section_nr; + + ms->section_mem_map |= SECTION_MARKED_PRESENT; +} +#endif /* CONFIG_SPARSEMEM */ + +/* + * mm/sparse-vmemmap.c + */ +#ifdef CONFIG_SPARSEMEM_VMEMMAP +void sparse_init_subsection_map(unsigned long pfn, unsigned long nr_pages); +#else +static inline void sparse_init_subsection_map(unsigned long pfn, + unsigned long nr_pages) +{ +} +#endif /* CONFIG_SPARSEMEM_VMEMMAP */ + #if defined CONFIG_COMPACTION || defined CONFIG_CMA /* diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 6a7714179c205d..e4c2ca8d97d542 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -584,6 +584,7 @@ void remove_pfn_range_from_zone(struct zone *zone, * @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 + * @pgmap: device page map or %NULL if not ZONE_DEVICE * * Generic helper function to remove section mappings and sysfs entries * for the section of the memory we are removing. Caller needs to make @@ -591,7 +592,7 @@ void remove_pfn_range_from_zone(struct zone *zone, * calling offline_pages(). */ void __remove_pages(unsigned long pfn, unsigned long nr_pages, - struct vmem_altmap *altmap) + struct vmem_altmap *altmap, struct dev_pagemap *pgmap) { const unsigned long end_pfn = pfn + nr_pages; unsigned long cur_nr_pages; @@ -606,7 +607,7 @@ void __remove_pages(unsigned long pfn, unsigned long 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); - sparse_remove_section(pfn, cur_nr_pages, altmap); + sparse_remove_section(pfn, cur_nr_pages, altmap, pgmap); } } @@ -1444,7 +1445,7 @@ static void remove_memory_blocks_and_altmaps(u64 start, u64 size) remove_memory_block_devices(cur_start, memblock_size); - arch_remove_memory(cur_start, memblock_size, altmap); + arch_remove_memory(cur_start, memblock_size, altmap, NULL); /* Verify that all vmemmap pages have actually been freed. */ WARN(altmap->alloc, "Altmap not fully unmapped"); @@ -1489,7 +1490,7 @@ static int create_altmaps_and_memory_blocks(int nid, struct memory_group *group, ret = create_memory_block_devices(cur_start, memblock_size, nid, params.altmap, group); if (ret) { - arch_remove_memory(cur_start, memblock_size, NULL); + arch_remove_memory(cur_start, memblock_size, params.altmap, NULL); kfree(params.altmap); goto out; } @@ -1575,7 +1576,7 @@ int add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) /* 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); + arch_remove_memory(start, size, params.altmap, NULL); goto error; } } @@ -2282,7 +2283,7 @@ static int try_remove_memory(u64 start, u64 size) * No altmaps present, do the removal directly */ remove_memory_block_devices(start, size); - arch_remove_memory(start, size, NULL); + arch_remove_memory(start, size, NULL, NULL); } else { /* all memblocks in the range have altmaps */ remove_memory_blocks_and_altmaps(start, size); diff --git a/mm/memremap.c b/mm/memremap.c index 46cb1b0b6f7223..48459d0d26b378 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -97,10 +97,10 @@ static void pageunmap_range(struct dev_pagemap *pgmap, int range_id) PHYS_PFN(range_len(range))); if (pgmap->type == MEMORY_DEVICE_PRIVATE) { __remove_pages(PHYS_PFN(range->start), - PHYS_PFN(range_len(range)), NULL); + PHYS_PFN(range_len(range)), NULL, pgmap); } else { arch_remove_memory(range->start, range_len(range), - pgmap_altmap(pgmap)); + pgmap_altmap(pgmap), pgmap); kasan_remove_zero_shadow(__va(range->start), range_len(range)); } mem_hotplug_done(); diff --git a/mm/mm_init.c b/mm/mm_init.c index 7712d887b6963b..10e1a1f7296737 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -1891,7 +1891,7 @@ void __init free_area_init(unsigned long *max_zone_pfn) pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid, (u64)start_pfn << PAGE_SHIFT, ((u64)end_pfn << PAGE_SHIFT) - 1); - subsection_map_init(start_pfn, end_pfn - start_pfn); + sparse_init_subsection_map(start_pfn, end_pfn - start_pfn); } /* Initialise every node */ diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index 37522d6cb39885..2c9fbc07c95697 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -605,3 +605,325 @@ void __init sparse_vmemmap_init_nid_late(int nid) hugetlb_vmemmap_init_late(nid); } #endif + +static void subsection_mask_set(unsigned long *map, unsigned long pfn, + unsigned long nr_pages) +{ + int idx = subsection_map_index(pfn); + int end = subsection_map_index(pfn + nr_pages - 1); + + bitmap_set(map, idx, end - idx + 1); +} + +void __init sparse_init_subsection_map(unsigned long pfn, unsigned long nr_pages) +{ + int end_sec_nr = pfn_to_section_nr(pfn + nr_pages - 1); + unsigned long nr, start_sec_nr = pfn_to_section_nr(pfn); + + for (nr = start_sec_nr; nr <= end_sec_nr; nr++) { + struct mem_section *ms; + unsigned long pfns; + + pfns = min(nr_pages, PAGES_PER_SECTION + - (pfn & ~PAGE_SECTION_MASK)); + ms = __nr_to_section(nr); + subsection_mask_set(ms->usage->subsection_map, pfn, pfns); + + pr_debug("%s: sec: %lu pfns: %lu set(%d, %d)\n", __func__, nr, + pfns, subsection_map_index(pfn), + subsection_map_index(pfn + pfns - 1)); + + pfn += pfns; + nr_pages -= pfns; + } +} + +#ifdef CONFIG_MEMORY_HOTPLUG + +/* Mark all memory sections within the pfn range as online */ +void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn) +{ + unsigned long pfn; + + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + unsigned long section_nr = pfn_to_section_nr(pfn); + struct mem_section *ms; + + /* onlining code should never touch invalid ranges */ + if (WARN_ON(!valid_section_nr(section_nr))) + continue; + + ms = __nr_to_section(section_nr); + ms->section_mem_map |= SECTION_IS_ONLINE; + } +} + +/* Mark all memory sections within the pfn range as offline */ +void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn) +{ + unsigned long pfn; + + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + unsigned long section_nr = pfn_to_section_nr(pfn); + struct mem_section *ms; + + /* + * TODO this needs some double checking. Offlining code makes + * sure to check pfn_valid but those checks might be just bogus + */ + if (WARN_ON(!valid_section_nr(section_nr))) + continue; + + ms = __nr_to_section(section_nr); + ms->section_mem_map &= ~SECTION_IS_ONLINE; + } +} + +static struct page * __meminit populate_section_memmap(unsigned long pfn, + unsigned long nr_pages, int nid, struct vmem_altmap *altmap, + struct dev_pagemap *pgmap) +{ + struct page *page = __populate_section_memmap(pfn, nr_pages, nid, altmap, + pgmap); + + memmap_pages_add(DIV_ROUND_UP(nr_pages * sizeof(struct page), PAGE_SIZE)); + + return page; +} + +static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages, + struct vmem_altmap *altmap, struct dev_pagemap *pgmap) +{ + unsigned long start = (unsigned long) pfn_to_page(pfn); + unsigned long end = start + nr_pages * sizeof(struct page); + + memmap_pages_add(-1L * (DIV_ROUND_UP(nr_pages * sizeof(struct page), PAGE_SIZE))); + vmemmap_free(start, end, altmap); +} + +static void free_map_bootmem(struct page *memmap) +{ + unsigned long start = (unsigned long)memmap; + unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION); + + memmap_boot_pages_add(-1L * (DIV_ROUND_UP(PAGES_PER_SECTION * sizeof(struct page), + PAGE_SIZE))); + vmemmap_free(start, end, NULL); +} + +static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages) +{ + DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; + DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 }; + struct mem_section *ms = __pfn_to_section(pfn); + unsigned long *subsection_map = ms->usage + ? &ms->usage->subsection_map[0] : NULL; + + subsection_mask_set(map, pfn, nr_pages); + if (subsection_map) + bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION); + + if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION), + "section already deactivated (%#lx + %ld)\n", + pfn, nr_pages)) + return -EINVAL; + + bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION); + return 0; +} + +static bool is_subsection_map_empty(struct mem_section *ms) +{ + return bitmap_empty(&ms->usage->subsection_map[0], + SUBSECTIONS_PER_SECTION); +} + +static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages) +{ + struct mem_section *ms = __pfn_to_section(pfn); + DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; + unsigned long *subsection_map; + int rc = 0; + + subsection_mask_set(map, pfn, nr_pages); + + subsection_map = &ms->usage->subsection_map[0]; + + if (bitmap_empty(map, SUBSECTIONS_PER_SECTION)) + rc = -EINVAL; + else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION)) + rc = -EEXIST; + else + bitmap_or(subsection_map, map, subsection_map, + SUBSECTIONS_PER_SECTION); + + return rc; +} + +/* + * To deactivate a memory region, there are 3 cases to handle: + * + * 1. deactivation of a partial hot-added section: + * a) section was present at memory init. + * b) section was hot-added post memory init. + * 2. deactivation of a complete hot-added section. + * 3. deactivation of a complete section from memory init. + * + * For 1, when subsection_map does not empty we will not be freeing the + * usage map, but still need to free the vmemmap range. + */ +static void section_deactivate(unsigned long pfn, unsigned long nr_pages, + struct vmem_altmap *altmap, struct dev_pagemap *pgmap) +{ + struct mem_section *ms = __pfn_to_section(pfn); + bool section_is_early = early_section(ms); + struct page *memmap = NULL; + bool empty; + + if (clear_subsection_map(pfn, nr_pages)) + return; + + empty = is_subsection_map_empty(ms); + if (empty) { + /* + * Mark the section invalid so that valid_section() + * return false. This prevents code from dereferencing + * ms->usage array. + */ + ms->section_mem_map &= ~SECTION_HAS_MEM_MAP; + + /* + * When removing an early section, the usage map is kept (as the + * usage maps of other sections fall into the same page). It + * will be re-used when re-adding the section - which is then no + * longer an early section. If the usage map is PageReserved, it + * was allocated during boot. + */ + if (!PageReserved(virt_to_page(ms->usage))) { + kfree_rcu(ms->usage, rcu); + WRITE_ONCE(ms->usage, NULL); + } + memmap = pfn_to_page(SECTION_ALIGN_DOWN(pfn)); + } + + /* + * The memmap of early sections is always fully populated. See + * section_activate() and pfn_valid() . + */ + if (!section_is_early) + depopulate_section_memmap(pfn, nr_pages, altmap, pgmap); + else if (memmap) + free_map_bootmem(memmap); + + if (empty) + ms->section_mem_map = (unsigned long)NULL; +} + +static struct page * __meminit section_activate(int nid, unsigned long pfn, + unsigned long nr_pages, struct vmem_altmap *altmap, + struct dev_pagemap *pgmap) +{ + struct mem_section *ms = __pfn_to_section(pfn); + struct mem_section_usage *usage = NULL; + struct page *memmap; + int rc; + + if (!ms->usage) { + usage = kzalloc(mem_section_usage_size(), GFP_KERNEL); + if (!usage) + return ERR_PTR(-ENOMEM); + ms->usage = usage; + } + + rc = fill_subsection_map(pfn, nr_pages); + if (rc) { + if (usage) + ms->usage = NULL; + kfree(usage); + return ERR_PTR(rc); + } + + /* + * The early init code does not consider partially populated + * initial sections, it simply assumes that memory will never be + * referenced. If we hot-add memory into such a section then we + * do not need to populate the memmap and can simply reuse what + * is already there. + */ + if (nr_pages < PAGES_PER_SECTION && early_section(ms)) + return pfn_to_page(pfn); + + memmap = populate_section_memmap(pfn, nr_pages, nid, altmap, pgmap); + if (!memmap) { + section_deactivate(pfn, nr_pages, altmap, pgmap); + return ERR_PTR(-ENOMEM); + } + + return memmap; +} + +/** + * sparse_add_section - add a memory section, or populate an existing one + * @nid: The node to add section on + * @start_pfn: start pfn of the memory range + * @nr_pages: number of pfns to add in the section + * @altmap: alternate pfns to allocate the memmap backing store + * @pgmap: alternate compound page geometry for devmap mappings + * + * This is only intended for hotplug. + * + * Note that only VMEMMAP supports sub-section aligned hotplug, + * the proper alignment and size are gated by check_pfn_span(). + * + * + * Return: + * * 0 - On success. + * * -EEXIST - Section has been present. + * * -ENOMEM - Out of memory. + */ +int __meminit sparse_add_section(int nid, unsigned long start_pfn, + unsigned long nr_pages, struct vmem_altmap *altmap, + struct dev_pagemap *pgmap) +{ + unsigned long section_nr = pfn_to_section_nr(start_pfn); + struct mem_section *ms; + struct page *memmap; + int ret; + + ret = sparse_index_init(section_nr, nid); + if (ret < 0) + return ret; + + memmap = section_activate(nid, start_pfn, nr_pages, altmap, pgmap); + if (IS_ERR(memmap)) + return PTR_ERR(memmap); + + /* + * Poison uninitialized struct pages in order to catch invalid flags + * combinations. + */ + if (!altmap || !altmap->inaccessible) + page_init_poison(memmap, sizeof(struct page) * nr_pages); + + ms = __nr_to_section(section_nr); + __section_mark_present(ms, section_nr); + + /* Align memmap to section boundary in the subsection case */ + if (section_nr_to_pfn(section_nr) != start_pfn) + memmap = pfn_to_page(section_nr_to_pfn(section_nr)); + sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0); + + return 0; +} + +void sparse_remove_section(unsigned long pfn, unsigned long nr_pages, + struct vmem_altmap *altmap, struct dev_pagemap *pgmap) +{ + struct mem_section *ms = __pfn_to_section(pfn); + + if (WARN_ON_ONCE(!valid_section(ms))) + return; + + section_deactivate(pfn, nr_pages, altmap, pgmap); +} +#endif /* CONFIG_MEMORY_HOTPLUG */ diff --git a/mm/sparse.c b/mm/sparse.c index 17c50a6415c2db..9d36ed6a1db676 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -79,7 +79,7 @@ static noinline struct mem_section __ref *sparse_index_alloc(int nid) return section; } -static int __meminit sparse_index_init(unsigned long section_nr, int nid) +int __meminit sparse_index_init(unsigned long section_nr, int nid) { unsigned long root = SECTION_NR_TO_ROOT(section_nr); struct mem_section *section; @@ -103,7 +103,7 @@ static int __meminit sparse_index_init(unsigned long section_nr, int nid) return 0; } #else /* !SPARSEMEM_EXTREME */ -static inline int sparse_index_init(unsigned long section_nr, int nid) +int sparse_index_init(unsigned long section_nr, int nid) { return 0; } @@ -161,58 +161,12 @@ static void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn, * those loops early. */ unsigned long __highest_present_section_nr; -static void __section_mark_present(struct mem_section *ms, - unsigned long section_nr) -{ - if (section_nr > __highest_present_section_nr) - __highest_present_section_nr = section_nr; - - ms->section_mem_map |= SECTION_MARKED_PRESENT; -} static inline unsigned long first_present_section_nr(void) { return next_present_section_nr(-1); } -#ifdef CONFIG_SPARSEMEM_VMEMMAP -static void subsection_mask_set(unsigned long *map, unsigned long pfn, - unsigned long nr_pages) -{ - int idx = subsection_map_index(pfn); - int end = subsection_map_index(pfn + nr_pages - 1); - - bitmap_set(map, idx, end - idx + 1); -} - -void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages) -{ - int end_sec_nr = pfn_to_section_nr(pfn + nr_pages - 1); - unsigned long nr, start_sec_nr = pfn_to_section_nr(pfn); - - for (nr = start_sec_nr; nr <= end_sec_nr; nr++) { - struct mem_section *ms; - unsigned long pfns; - - pfns = min(nr_pages, PAGES_PER_SECTION - - (pfn & ~PAGE_SECTION_MASK)); - ms = __nr_to_section(nr); - subsection_mask_set(ms->usage->subsection_map, pfn, pfns); - - pr_debug("%s: sec: %lu pfns: %lu set(%d, %d)\n", __func__, nr, - pfns, subsection_map_index(pfn), - subsection_map_index(pfn + pfns - 1)); - - pfn += pfns; - nr_pages -= pfns; - } -} -#else -void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages) -{ -} -#endif - /* Record a memory area against a node. */ static void __init memory_present(int nid, unsigned long start, unsigned long end) { @@ -260,20 +214,6 @@ static void __init memblocks_present(void) memory_present(nid, start, end); } -/* - * Subtle, we encode the real pfn into the mem_map such that - * the identity pfn - section_mem_map will return the actual - * physical page frame number. - */ -static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum) -{ - unsigned long coded_mem_map = - (unsigned long)(mem_map - (section_nr_to_pfn(pnum))); - BUILD_BUG_ON(SECTION_MAP_LAST_BIT > PFN_SECTION_SHIFT); - BUG_ON(coded_mem_map & ~SECTION_MAP_MASK); - return coded_mem_map; -} - #ifdef CONFIG_MEMORY_HOTPLUG /* * Decode mem_map from the coded memmap @@ -286,16 +226,6 @@ struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pn } #endif /* CONFIG_MEMORY_HOTPLUG */ -static void __meminit sparse_init_one_section(struct mem_section *ms, - unsigned long pnum, struct page *mem_map, - struct mem_section_usage *usage, unsigned long flags) -{ - ms->section_mem_map &= ~SECTION_MAP_MASK; - ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) - | SECTION_HAS_MEM_MAP | flags; - ms->usage = usage; -} - static unsigned long usemap_size(void) { return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long); @@ -623,357 +553,3 @@ void __init sparse_init(void) sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count); vmemmap_populate_print_last(); } - -#ifdef CONFIG_MEMORY_HOTPLUG - -/* Mark all memory sections within the pfn range as online */ -void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn) -{ - unsigned long pfn; - - for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { - unsigned long section_nr = pfn_to_section_nr(pfn); - struct mem_section *ms; - - /* onlining code should never touch invalid ranges */ - if (WARN_ON(!valid_section_nr(section_nr))) - continue; - - ms = __nr_to_section(section_nr); - ms->section_mem_map |= SECTION_IS_ONLINE; - } -} - -/* Mark all memory sections within the pfn range as offline */ -void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn) -{ - unsigned long pfn; - - for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { - unsigned long section_nr = pfn_to_section_nr(pfn); - struct mem_section *ms; - - /* - * TODO this needs some double checking. Offlining code makes - * sure to check pfn_valid but those checks might be just bogus - */ - if (WARN_ON(!valid_section_nr(section_nr))) - continue; - - ms = __nr_to_section(section_nr); - ms->section_mem_map &= ~SECTION_IS_ONLINE; - } -} - -#ifdef CONFIG_SPARSEMEM_VMEMMAP -static struct page * __meminit populate_section_memmap(unsigned long pfn, - unsigned long nr_pages, int nid, struct vmem_altmap *altmap, - struct dev_pagemap *pgmap) -{ - return __populate_section_memmap(pfn, nr_pages, nid, altmap, pgmap); -} - -static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages, - struct vmem_altmap *altmap) -{ - unsigned long start = (unsigned long) pfn_to_page(pfn); - unsigned long end = start + nr_pages * sizeof(struct page); - - vmemmap_free(start, end, altmap); -} -static void free_map_bootmem(struct page *memmap) -{ - unsigned long start = (unsigned long)memmap; - unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION); - - vmemmap_free(start, end, NULL); -} - -static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages) -{ - DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; - DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 }; - struct mem_section *ms = __pfn_to_section(pfn); - unsigned long *subsection_map = ms->usage - ? &ms->usage->subsection_map[0] : NULL; - - subsection_mask_set(map, pfn, nr_pages); - if (subsection_map) - bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION); - - if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION), - "section already deactivated (%#lx + %ld)\n", - pfn, nr_pages)) - return -EINVAL; - - bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION); - return 0; -} - -static bool is_subsection_map_empty(struct mem_section *ms) -{ - return bitmap_empty(&ms->usage->subsection_map[0], - SUBSECTIONS_PER_SECTION); -} - -static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages) -{ - struct mem_section *ms = __pfn_to_section(pfn); - DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; - unsigned long *subsection_map; - int rc = 0; - - subsection_mask_set(map, pfn, nr_pages); - - subsection_map = &ms->usage->subsection_map[0]; - - if (bitmap_empty(map, SUBSECTIONS_PER_SECTION)) - rc = -EINVAL; - else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION)) - rc = -EEXIST; - else - bitmap_or(subsection_map, map, subsection_map, - SUBSECTIONS_PER_SECTION); - - return rc; -} -#else -static struct page * __meminit populate_section_memmap(unsigned long pfn, - unsigned long nr_pages, int nid, struct vmem_altmap *altmap, - struct dev_pagemap *pgmap) -{ - return kvmalloc_node(array_size(sizeof(struct page), - PAGES_PER_SECTION), GFP_KERNEL, nid); -} - -static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages, - struct vmem_altmap *altmap) -{ - kvfree(pfn_to_page(pfn)); -} - -static void free_map_bootmem(struct page *memmap) -{ - unsigned long maps_section_nr, removing_section_nr, i; - unsigned long type, nr_pages; - struct page *page = virt_to_page(memmap); - - nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) - >> PAGE_SHIFT; - - for (i = 0; i < nr_pages; i++, page++) { - type = bootmem_type(page); - - BUG_ON(type == NODE_INFO); - - maps_section_nr = pfn_to_section_nr(page_to_pfn(page)); - removing_section_nr = bootmem_info(page); - - /* - * When this function is called, the removing section is - * logical offlined state. This means all pages are isolated - * from page allocator. If removing section's memmap is placed - * on the same section, it must not be freed. - * If it is freed, page allocator may allocate it which will - * be removed physically soon. - */ - if (maps_section_nr != removing_section_nr) - put_page_bootmem(page); - } -} - -static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages) -{ - return 0; -} - -static bool is_subsection_map_empty(struct mem_section *ms) -{ - return true; -} - -static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages) -{ - return 0; -} -#endif /* CONFIG_SPARSEMEM_VMEMMAP */ - -/* - * To deactivate a memory region, there are 3 cases to handle across - * two configurations (SPARSEMEM_VMEMMAP={y,n}): - * - * 1. deactivation of a partial hot-added section (only possible in - * the SPARSEMEM_VMEMMAP=y case). - * a) section was present at memory init. - * b) section was hot-added post memory init. - * 2. deactivation of a complete hot-added section. - * 3. deactivation of a complete section from memory init. - * - * For 1, when subsection_map does not empty we will not be freeing the - * usage map, but still need to free the vmemmap range. - * - * For 2 and 3, the SPARSEMEM_VMEMMAP={y,n} cases are unified - */ -static void section_deactivate(unsigned long pfn, unsigned long nr_pages, - struct vmem_altmap *altmap) -{ - struct mem_section *ms = __pfn_to_section(pfn); - bool section_is_early = early_section(ms); - struct page *memmap = NULL; - bool empty; - - if (clear_subsection_map(pfn, nr_pages)) - return; - - empty = is_subsection_map_empty(ms); - if (empty) { - unsigned long section_nr = pfn_to_section_nr(pfn); - - /* - * Mark the section invalid so that valid_section() - * return false. This prevents code from dereferencing - * ms->usage array. - */ - ms->section_mem_map &= ~SECTION_HAS_MEM_MAP; - - /* - * When removing an early section, the usage map is kept (as the - * usage maps of other sections fall into the same page). It - * will be re-used when re-adding the section - which is then no - * longer an early section. If the usage map is PageReserved, it - * was allocated during boot. - */ - if (!PageReserved(virt_to_page(ms->usage))) { - kfree_rcu(ms->usage, rcu); - WRITE_ONCE(ms->usage, NULL); - } - memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); - } - - /* - * The memmap of early sections is always fully populated. See - * section_activate() and pfn_valid() . - */ - if (!section_is_early) { - memmap_pages_add(-1L * (DIV_ROUND_UP(nr_pages * sizeof(struct page), PAGE_SIZE))); - depopulate_section_memmap(pfn, nr_pages, altmap); - } else if (memmap) { - memmap_boot_pages_add(-1L * (DIV_ROUND_UP(nr_pages * sizeof(struct page), - PAGE_SIZE))); - free_map_bootmem(memmap); - } - - if (empty) - ms->section_mem_map = (unsigned long)NULL; -} - -static struct page * __meminit section_activate(int nid, unsigned long pfn, - unsigned long nr_pages, struct vmem_altmap *altmap, - struct dev_pagemap *pgmap) -{ - struct mem_section *ms = __pfn_to_section(pfn); - struct mem_section_usage *usage = NULL; - struct page *memmap; - int rc; - - if (!ms->usage) { - usage = kzalloc(mem_section_usage_size(), GFP_KERNEL); - if (!usage) - return ERR_PTR(-ENOMEM); - ms->usage = usage; - } - - rc = fill_subsection_map(pfn, nr_pages); - if (rc) { - if (usage) - ms->usage = NULL; - kfree(usage); - return ERR_PTR(rc); - } - - /* - * The early init code does not consider partially populated - * initial sections, it simply assumes that memory will never be - * referenced. If we hot-add memory into such a section then we - * do not need to populate the memmap and can simply reuse what - * is already there. - */ - if (nr_pages < PAGES_PER_SECTION && early_section(ms)) - return pfn_to_page(pfn); - - memmap = populate_section_memmap(pfn, nr_pages, nid, altmap, pgmap); - if (!memmap) { - section_deactivate(pfn, nr_pages, altmap); - return ERR_PTR(-ENOMEM); - } - memmap_pages_add(DIV_ROUND_UP(nr_pages * sizeof(struct page), PAGE_SIZE)); - - return memmap; -} - -/** - * sparse_add_section - add a memory section, or populate an existing one - * @nid: The node to add section on - * @start_pfn: start pfn of the memory range - * @nr_pages: number of pfns to add in the section - * @altmap: alternate pfns to allocate the memmap backing store - * @pgmap: alternate compound page geometry for devmap mappings - * - * This is only intended for hotplug. - * - * Note that only VMEMMAP supports sub-section aligned hotplug, - * the proper alignment and size are gated by check_pfn_span(). - * - * - * Return: - * * 0 - On success. - * * -EEXIST - Section has been present. - * * -ENOMEM - Out of memory. - */ -int __meminit sparse_add_section(int nid, unsigned long start_pfn, - unsigned long nr_pages, struct vmem_altmap *altmap, - struct dev_pagemap *pgmap) -{ - unsigned long section_nr = pfn_to_section_nr(start_pfn); - struct mem_section *ms; - struct page *memmap; - int ret; - - ret = sparse_index_init(section_nr, nid); - if (ret < 0) - return ret; - - memmap = section_activate(nid, start_pfn, nr_pages, altmap, pgmap); - if (IS_ERR(memmap)) - return PTR_ERR(memmap); - - /* - * Poison uninitialized struct pages in order to catch invalid flags - * combinations. - */ - if (!altmap || !altmap->inaccessible) - page_init_poison(memmap, sizeof(struct page) * nr_pages); - - ms = __nr_to_section(section_nr); - set_section_nid(section_nr, nid); - __section_mark_present(ms, section_nr); - - /* Align memmap to section boundary in the subsection case */ - if (section_nr_to_pfn(section_nr) != start_pfn) - memmap = pfn_to_page(section_nr_to_pfn(section_nr)); - sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0); - - return 0; -} - -void sparse_remove_section(unsigned long pfn, unsigned long nr_pages, - struct vmem_altmap *altmap) -{ - struct mem_section *ms = __pfn_to_section(pfn); - - if (WARN_ON_ONCE(!valid_section(ms))) - return; - - section_deactivate(pfn, nr_pages, altmap); -} -#endif /* CONFIG_MEMORY_HOTPLUG */ -- 2.53.0