There are problems in the use of SPARSEMEM and pageblock flags that causes problems on ia64. The first part of the problem is that units are incorrect in SECTION_BLOCKFLAGS_BITS computation. This results in a map_section's section_mem_map being treated as part of a bitmap which isn't good. This was evident with an invalid virtual address when mem_init attempted to free bootmem pages while relinquishing control from the bootmem allocator. The second part of the problem occurs because the pageblock flags bitmap is be located with the mem_section. The SECTIONS_PER_ROOT computation using sizeof (mem_section) may not be a power of 2 depending on the size of the bitmap. This renders masks and other such things not power of 2 base. This issue was seen with SPARSEMEM_EXTREME on ia64. This patch moves the bitmap outside of mem_section and uses a pointer instead in the mem_section. The bitmaps are allocated when the section is being initialised. Note that sparse_early_usemap_alloc() does not use alloc_remap() like sparse_early_mem_map_alloc(). The allocation required for the bitmap on x86, the only architecture that uses alloc_remap is typically smaller than a cache line. alloc_remap() pads out allocations to the cache size which would be a needless waste. Credit to Bob Picco for identifying the original problem and effecting a fix for the SECTION_BLOCKFLAGS_BITS calculation. Credit to Andy Whitcroft for devising the best way of allocating the bitmaps only when required for the section. [wli@holomorphy.com: warning fix] Signed-off-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: William Irwin <bill.irwin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
411 lines
9.7 KiB
C
411 lines
9.7 KiB
C
/*
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* sparse memory mappings.
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*/
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#include <linux/mm.h>
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#include <linux/mmzone.h>
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#include <linux/bootmem.h>
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#include <linux/highmem.h>
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#include <linux/module.h>
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#include <linux/spinlock.h>
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#include <linux/vmalloc.h>
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#include <asm/dma.h>
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#include <asm/pgalloc.h>
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#include <asm/pgtable.h>
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/*
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* Permanent SPARSEMEM data:
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*
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* 1) mem_section - memory sections, mem_map's for valid memory
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*/
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#ifdef CONFIG_SPARSEMEM_EXTREME
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struct mem_section *mem_section[NR_SECTION_ROOTS]
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____cacheline_internodealigned_in_smp;
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#else
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struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
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____cacheline_internodealigned_in_smp;
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#endif
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EXPORT_SYMBOL(mem_section);
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#ifdef NODE_NOT_IN_PAGE_FLAGS
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/*
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* If we did not store the node number in the page then we have to
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* do a lookup in the section_to_node_table in order to find which
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* node the page belongs to.
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*/
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#if MAX_NUMNODES <= 256
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static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
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#else
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static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
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#endif
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int page_to_nid(struct page *page)
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{
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return section_to_node_table[page_to_section(page)];
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}
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EXPORT_SYMBOL(page_to_nid);
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static void set_section_nid(unsigned long section_nr, int nid)
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{
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section_to_node_table[section_nr] = nid;
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}
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#else /* !NODE_NOT_IN_PAGE_FLAGS */
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static inline void set_section_nid(unsigned long section_nr, int nid)
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{
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}
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#endif
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#ifdef CONFIG_SPARSEMEM_EXTREME
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static struct mem_section noinline __init_refok *sparse_index_alloc(int nid)
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{
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struct mem_section *section = NULL;
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unsigned long array_size = SECTIONS_PER_ROOT *
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sizeof(struct mem_section);
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if (slab_is_available())
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section = kmalloc_node(array_size, GFP_KERNEL, nid);
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else
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section = alloc_bootmem_node(NODE_DATA(nid), array_size);
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if (section)
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memset(section, 0, array_size);
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return section;
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}
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static int __meminit sparse_index_init(unsigned long section_nr, int nid)
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{
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static DEFINE_SPINLOCK(index_init_lock);
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unsigned long root = SECTION_NR_TO_ROOT(section_nr);
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struct mem_section *section;
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int ret = 0;
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if (mem_section[root])
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return -EEXIST;
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section = sparse_index_alloc(nid);
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/*
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* This lock keeps two different sections from
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* reallocating for the same index
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*/
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spin_lock(&index_init_lock);
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if (mem_section[root]) {
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ret = -EEXIST;
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goto out;
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}
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mem_section[root] = section;
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out:
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spin_unlock(&index_init_lock);
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return ret;
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}
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#else /* !SPARSEMEM_EXTREME */
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static inline int sparse_index_init(unsigned long section_nr, int nid)
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{
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return 0;
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}
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#endif
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/*
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* Although written for the SPARSEMEM_EXTREME case, this happens
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* to also work for the flat array case because
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* NR_SECTION_ROOTS==NR_MEM_SECTIONS.
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*/
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int __section_nr(struct mem_section* ms)
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{
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unsigned long root_nr;
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struct mem_section* root;
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for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
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root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
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if (!root)
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continue;
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if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
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break;
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}
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return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
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}
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/*
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* During early boot, before section_mem_map is used for an actual
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* mem_map, we use section_mem_map to store the section's NUMA
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* node. This keeps us from having to use another data structure. The
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* node information is cleared just before we store the real mem_map.
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*/
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static inline unsigned long sparse_encode_early_nid(int nid)
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{
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return (nid << SECTION_NID_SHIFT);
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}
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static inline int sparse_early_nid(struct mem_section *section)
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{
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return (section->section_mem_map >> SECTION_NID_SHIFT);
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}
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/* Record a memory area against a node. */
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void __init memory_present(int nid, unsigned long start, unsigned long end)
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{
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unsigned long pfn;
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start &= PAGE_SECTION_MASK;
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for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
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unsigned long section = pfn_to_section_nr(pfn);
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struct mem_section *ms;
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sparse_index_init(section, nid);
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set_section_nid(section, nid);
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ms = __nr_to_section(section);
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if (!ms->section_mem_map)
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ms->section_mem_map = sparse_encode_early_nid(nid) |
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SECTION_MARKED_PRESENT;
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}
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}
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/*
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* Only used by the i386 NUMA architecures, but relatively
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* generic code.
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*/
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unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn,
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unsigned long end_pfn)
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{
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unsigned long pfn;
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unsigned long nr_pages = 0;
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for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
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if (nid != early_pfn_to_nid(pfn))
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continue;
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if (pfn_present(pfn))
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nr_pages += PAGES_PER_SECTION;
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}
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return nr_pages * sizeof(struct page);
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}
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/*
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* Subtle, we encode the real pfn into the mem_map such that
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* the identity pfn - section_mem_map will return the actual
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* physical page frame number.
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*/
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static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
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{
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return (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
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}
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/*
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* We need this if we ever free the mem_maps. While not implemented yet,
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* this function is included for parity with its sibling.
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*/
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static __attribute((unused))
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struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
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{
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return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
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}
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static int __meminit sparse_init_one_section(struct mem_section *ms,
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unsigned long pnum, struct page *mem_map,
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unsigned long *pageblock_bitmap)
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{
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if (!present_section(ms))
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return -EINVAL;
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ms->section_mem_map &= ~SECTION_MAP_MASK;
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ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
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SECTION_HAS_MEM_MAP;
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ms->pageblock_flags = pageblock_bitmap;
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return 1;
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}
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__attribute__((weak)) __init
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void *alloc_bootmem_high_node(pg_data_t *pgdat, unsigned long size)
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{
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return NULL;
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}
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static unsigned long usemap_size(void)
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{
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unsigned long size_bytes;
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size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;
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size_bytes = roundup(size_bytes, sizeof(unsigned long));
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return size_bytes;
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}
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#ifdef CONFIG_MEMORY_HOTPLUG
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static unsigned long *__kmalloc_section_usemap(void)
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{
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return kmalloc(usemap_size(), GFP_KERNEL);
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}
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#endif /* CONFIG_MEMORY_HOTPLUG */
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static unsigned long *sparse_early_usemap_alloc(unsigned long pnum)
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{
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unsigned long *usemap;
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struct mem_section *ms = __nr_to_section(pnum);
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int nid = sparse_early_nid(ms);
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usemap = alloc_bootmem_node(NODE_DATA(nid), usemap_size());
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if (usemap)
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return usemap;
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/* Stupid: suppress gcc warning for SPARSEMEM && !NUMA */
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nid = 0;
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printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__);
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return NULL;
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}
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#ifndef CONFIG_SPARSEMEM_VMEMMAP
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struct page __init *sparse_early_mem_map_populate(unsigned long pnum, int nid)
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{
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struct page *map;
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map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
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if (map)
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return map;
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map = alloc_bootmem_high_node(NODE_DATA(nid),
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sizeof(struct page) * PAGES_PER_SECTION);
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if (map)
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return map;
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map = alloc_bootmem_node(NODE_DATA(nid),
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sizeof(struct page) * PAGES_PER_SECTION);
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return map;
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}
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#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
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struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
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{
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struct page *map;
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struct mem_section *ms = __nr_to_section(pnum);
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int nid = sparse_early_nid(ms);
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map = sparse_early_mem_map_populate(pnum, nid);
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if (map)
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return map;
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printk(KERN_ERR "%s: sparsemem memory map backing failed "
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"some memory will not be available.\n", __FUNCTION__);
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ms->section_mem_map = 0;
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return NULL;
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}
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/*
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* Allocate the accumulated non-linear sections, allocate a mem_map
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* for each and record the physical to section mapping.
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*/
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void __init sparse_init(void)
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{
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unsigned long pnum;
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struct page *map;
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unsigned long *usemap;
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for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
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if (!present_section_nr(pnum))
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continue;
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map = sparse_early_mem_map_alloc(pnum);
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if (!map)
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continue;
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usemap = sparse_early_usemap_alloc(pnum);
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if (!usemap)
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continue;
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sparse_init_one_section(__nr_to_section(pnum), pnum, map,
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usemap);
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}
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}
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#ifdef CONFIG_MEMORY_HOTPLUG
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static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
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{
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struct page *page, *ret;
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unsigned long memmap_size = sizeof(struct page) * nr_pages;
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page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
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if (page)
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goto got_map_page;
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ret = vmalloc(memmap_size);
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if (ret)
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goto got_map_ptr;
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return NULL;
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got_map_page:
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ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
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got_map_ptr:
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memset(ret, 0, memmap_size);
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return ret;
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}
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static int vaddr_in_vmalloc_area(void *addr)
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{
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if (addr >= (void *)VMALLOC_START &&
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addr < (void *)VMALLOC_END)
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return 1;
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return 0;
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}
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static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
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{
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if (vaddr_in_vmalloc_area(memmap))
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vfree(memmap);
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else
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free_pages((unsigned long)memmap,
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get_order(sizeof(struct page) * nr_pages));
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}
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/*
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* returns the number of sections whose mem_maps were properly
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* set. If this is <=0, then that means that the passed-in
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* map was not consumed and must be freed.
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*/
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int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
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int nr_pages)
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{
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unsigned long section_nr = pfn_to_section_nr(start_pfn);
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struct pglist_data *pgdat = zone->zone_pgdat;
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struct mem_section *ms;
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struct page *memmap;
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unsigned long *usemap;
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unsigned long flags;
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int ret;
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/*
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* no locking for this, because it does its own
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* plus, it does a kmalloc
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*/
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sparse_index_init(section_nr, pgdat->node_id);
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memmap = __kmalloc_section_memmap(nr_pages);
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usemap = __kmalloc_section_usemap();
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pgdat_resize_lock(pgdat, &flags);
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ms = __pfn_to_section(start_pfn);
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if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
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ret = -EEXIST;
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goto out;
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}
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if (!usemap) {
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ret = -ENOMEM;
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goto out;
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}
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ms->section_mem_map |= SECTION_MARKED_PRESENT;
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ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
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out:
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pgdat_resize_unlock(pgdat, &flags);
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if (ret <= 0)
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__kfree_section_memmap(memmap, nr_pages);
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return ret;
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}
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#endif
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