![Mike Kravetz](/assets/img/avatar_default.png)
slab_is_available() indicates slab based allocators are available for use. SPARSEMEM code needs to know this as it can be called at various times during the boot process. Signed-off-by: Mike Kravetz <kravetz@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
293 lines
6.7 KiB
C
293 lines
6.7 KiB
C
/*
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* sparse memory mappings.
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*/
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#include <linux/config.h>
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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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/*
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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 CONFIG_SPARSEMEM_EXTREME
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static struct mem_section *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 sparse_index_init(unsigned long section_nr, int nid)
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{
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static spinlock_t index_init_lock = SPIN_LOCK_UNLOCKED;
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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 becase
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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;
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root_nr < NR_MEM_SECTIONS;
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root_nr += SECTIONS_PER_ROOT) {
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root = __nr_to_section(root_nr);
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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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/* Record a memory area against a node. */
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void 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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ms = __nr_to_section(section);
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if (!ms->section_mem_map)
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ms->section_mem_map = 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_valid(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 sparse_init_one_section(struct mem_section *ms,
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unsigned long pnum, struct page *mem_map)
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{
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if (!valid_section(ms))
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return -EINVAL;
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ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum);
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return 1;
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}
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static struct page *sparse_early_mem_map_alloc(unsigned long pnum)
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{
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struct page *map;
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int nid = early_pfn_to_nid(section_nr_to_pfn(pnum));
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struct mem_section *ms = __nr_to_section(pnum);
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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_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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printk(KERN_WARNING "%s: allocation failed\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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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, 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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* 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 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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for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
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if (!valid_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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sparse_init_one_section(__nr_to_section(pnum), pnum, map);
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}
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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 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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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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ms->section_mem_map |= SECTION_MARKED_PRESENT;
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ret = sparse_init_one_section(ms, section_nr, memmap);
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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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