/* * bootmem - A boot-time physical memory allocator and configurator * * Copyright (C) 1999 Ingo Molnar * 1999 Kanoj Sarcar, SGI * 2008 Johannes Weiner * * Access to this subsystem has to be serialized externally (which is true * for the boot process anyway). */#include <linux/init.h>#include <linux/pfn.h>#include <linux/slab.h>#include <linux/bootmem.h>#include <linux/export.h>#include <linux/kmemleak.h>#include <linux/range.h>#include <linux/memblock.h> #include <asm/bug.h>#include <asm/io.h>#include <asm/processor.h> #include "internal.h" #ifndef CONFIG_NEED_MULTIPLE_NODESstruct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0]};EXPORT_SYMBOL(contig_page_data);#endif unsigned long max_low_pfn;unsigned long min_low_pfn;unsigned long max_pfn; bootmem_data_t bootmem_node_data[MAX_NUMNODES] __initdata; static struct list_head bdata_list __initdata = LIST_HEAD_INIT(bdata_list); static int bootmem_debug; static int __init bootmem_debug_setup(char *buf){ bootmem_debug = 1; return 0;}early_param("bootmem_debug", bootmem_debug_setup); #define bdebug(fmt, args...) ({ \ if (unlikely(bootmem_debug)) \ printk(KERN_INFO \ "bootmem::%s " fmt, \ __func__, ## args); \}) static unsigned long __init bootmap_bytes(unsigned long pages){ unsigned long bytes = DIV_ROUND_UP(pages, 8); return ALIGN(bytes, sizeof(long));} /** * bootmem_bootmap_pages - calculate bitmap size in pages * @pages: number of pages the bitmap has to represent */unsigned long __init bootmem_bootmap_pages(unsigned long pages){ unsigned long bytes = bootmap_bytes(pages); return PAGE_ALIGN(bytes) >> PAGE_SHIFT;} /* * link bdata in order */static void __init link_bootmem(bootmem_data_t *bdata){ bootmem_data_t *ent; list_for_each_entry(ent, &bdata_list, list) { if (bdata->node_min_pfn < ent->node_min_pfn) { list_add_tail(&bdata->list, &ent->list); return; } } list_add_tail(&bdata->list, &bdata_list);} /* * Called once to set up the allocator itself. */static unsigned long __init init_bootmem_core(bootmem_data_t *bdata, unsigned long mapstart, unsigned long start, unsigned long end){ unsigned long mapsize; mminit_validate_memmodel_limits(&start, &end); bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart)); bdata->node_min_pfn = start; bdata->node_low_pfn = end; link_bootmem(bdata); /* * Initially all pages are reserved - setup_arch() has to * register free RAM areas explicitly. */ mapsize = bootmap_bytes(end - start); memset(bdata->node_bootmem_map, 0xff, mapsize); bdebug("nid=%td start=%lx map=%lx end=%lx mapsize=%lx\n", bdata - bootmem_node_data, start, mapstart, end, mapsize); return mapsize;} /** * init_bootmem_node - register a node as boot memory * @pgdat: node to register * @freepfn: pfn where the bitmap for this node is to be placed * @startpfn: first pfn on the node * @endpfn: first pfn after the node * * Returns the number of bytes needed to hold the bitmap for this node. */unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn, unsigned long startpfn, unsigned long endpfn){ return init_bootmem_core(pgdat->bdata, freepfn, startpfn, endpfn);} /** * init_bootmem - register boot memory * @start: pfn where the bitmap is to be placed * @pages: number of available physical pages * * Returns the number of bytes needed to hold the bitmap. */unsigned long __init init_bootmem(unsigned long start, unsigned long pages){ max_low_pfn = pages; min_low_pfn = start; return init_bootmem_core(NODE_DATA(0)->bdata, start, 0, pages);} /* * free_bootmem_late - free bootmem pages directly to page allocator * @addr: starting address of the range * @size: size of the range in bytes * * This is only useful when the bootmem allocator has already been torn * down, but we are still initializing the system. Pages are given directly * to the page allocator, no bootmem metadata is updated because it is gone. */void __init free_bootmem_late(unsigned long addr, unsigned long size){ unsigned long cursor, end; kmemleak_free_part(__va(addr), size); cursor = PFN_UP(addr); end = PFN_DOWN(addr + size); for (; cursor < end; cursor++) { __free_pages_bootmem(pfn_to_page(cursor), 0); totalram_pages++; }} static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata){ struct page *page; unsigned long start, end, pages, count = 0; if (!bdata->node_bootmem_map) return 0; start = bdata->node_min_pfn; end = bdata->node_low_pfn; bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data, start, end); while (start < end) { unsigned long *map, idx, vec; map = bdata->node_bootmem_map; idx = start - bdata->node_min_pfn; vec = ~map[idx / BITS_PER_LONG]; /* * If we have a properly aligned and fully unreserved * BITS_PER_LONG block of pages in front of us, free * it in one go. */ if (IS_ALIGNED(start, BITS_PER_LONG) && vec == ~0UL) { int order = ilog2(BITS_PER_LONG); __free_pages_bootmem(pfn_to_page(start), order); count += BITS_PER_LONG; start += BITS_PER_LONG; } else { unsigned long off = 0; vec >>= start & (BITS_PER_LONG - 1); while (vec) { if (vec & 1) { page = pfn_to_page(start + off); __free_pages_bootmem(page, 0); count++; } vec >>= 1; off++; } start = ALIGN(start + 1, BITS_PER_LONG); } } page = virt_to_page(bdata->node_bootmem_map); pages = bdata->node_low_pfn - bdata->node_min_pfn; pages = bootmem_bootmap_pages(pages); count += pages; while (pages--) __free_pages_bootmem(page++, 0); bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count); return count;} /** * free_all_bootmem_node - release a node's free pages to the buddy allocator * @pgdat: node to be released * * Returns the number of pages actually released. */unsigned long __init free_all_bootmem_node(pg_data_t *pgdat){ register_page_bootmem_info_node(pgdat); return free_all_bootmem_core(pgdat->bdata);} /** * free_all_bootmem - release free pages to the buddy allocator * * Returns the number of pages actually released. */unsigned long __init free_all_bootmem(void){ unsigned long total_pages = 0; bootmem_data_t *bdata; list_for_each_entry(bdata, &bdata_list, list) total_pages += free_all_bootmem_core(bdata); return total_pages;} static void __init __free(bootmem_data_t *bdata, unsigned long sidx, unsigned long eidx){ unsigned long idx; bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data, sidx + bdata->node_min_pfn, eidx + bdata->node_min_pfn); if (bdata->hint_idx > sidx) bdata->hint_idx = sidx; for (idx = sidx; idx < eidx; idx++) if (!test_and_clear_bit(idx, bdata->node_bootmem_map)) BUG();} static int __init __reserve(bootmem_data_t *bdata, unsigned long sidx, unsigned long eidx, int flags){ unsigned long idx; int exclusive = flags & BOOTMEM_EXCLUSIVE; bdebug("nid=%td start=%lx end=%lx flags=%x\n", bdata - bootmem_node_data, sidx + bdata->node_min_pfn, eidx + bdata->node_min_pfn, flags); for (idx = sidx; idx < eidx; idx++) if (test_and_set_bit(idx, bdata->node_bootmem_map)) { if (exclusive) { __free(bdata, sidx, idx); return -EBUSY; } bdebug("silent double reserve of PFN %lx\n", idx + bdata->node_min_pfn); } return 0;} static int __init mark_bootmem_node(bootmem_data_t *bdata, unsigned long start, unsigned long end, int reserve, int flags){ unsigned long sidx, eidx; bdebug("nid=%td start=%lx end=%lx reserve=%d flags=%x\n", bdata - bootmem_node_data, start, end, reserve, flags); BUG_ON(start < bdata->node_min_pfn); BUG_ON(end > bdata->node_low_pfn); sidx = start - bdata->node_min_pfn; eidx = end - bdata->node_min_pfn; if (reserve) return __reserve(bdata, sidx, eidx, flags); else __free(bdata, sidx, eidx); return 0;} static int __init mark_bootmem(unsigned long start, unsigned long end, int reserve, int flags){ unsigned long pos; bootmem_data_t *bdata; pos = start; list_for_each_entry(bdata, &bdata_list, list) { int err; unsigned long max; if (pos < bdata->node_min_pfn || pos >= bdata->node_low_pfn) { BUG_ON(pos != start); continue; } max = min(bdata->node_low_pfn, end); err = mark_bootmem_node(bdata, pos, max, reserve, flags); if (reserve && err) { mark_bootmem(start, pos, 0, 0); return err; } if (max == end) return 0; pos = bdata->node_low_pfn; } BUG();} /** * free_bootmem_node - mark a page range as usable * @pgdat: node the range resides on * @physaddr: starting address of the range * @size: size of the range in bytes * * Partial pages will be considered reserved and left as they are. * * The range must reside completely on the specified node. */void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr, unsigned long size){ unsigned long start, end; kmemleak_free_part(__va(physaddr), size); start = PFN_UP(physaddr); end = PFN_DOWN(physaddr + size); mark_bootmem_node(pgdat->bdata, start, end, 0, 0);} /** * free_bootmem - mark a page range as usable * @addr: starting address of the range * @size: size of the range in bytes * * Partial pages will be considered reserved and left as they are. * * The range must be contiguous but may span node boundaries. */void __init free_bootmem(unsigned long addr, unsigned long size){ unsigned long start, end; kmemleak_free_part(__va(addr), size); start = PFN_UP(addr); end = PFN_DOWN(addr + size); mark_bootmem(start, end, 0, 0);} /** * reserve_bootmem_node - mark a page range as reserved * @pgdat: node the range resides on * @physaddr: starting address of the range * @size: size of the range in bytes * @flags: reservation flags (see linux/bootmem.h) * * Partial pages will be reserved. * * The range must reside completely on the specified node. */int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr, unsigned long size, int flags){ unsigned long start, end; start = PFN_DOWN(physaddr); end = PFN_UP(physaddr + size); return mark_bootmem_node(pgdat->bdata, start, end, 1, flags);} /** * reserve_bootmem - mark a page range as usable * @addr: starting address of the range * @size: size of the range in bytes * @flags: reservation flags (see linux/bootmem.h) * * Partial pages will be reserved. * * The range must be contiguous but may span node boundaries. */int __init reserve_bootmem(unsigned long addr, unsigned long size, int flags){ unsigned long start, end; start = PFN_DOWN(addr); end = PFN_UP(addr + size); return mark_bootmem(start, end, 1, flags);} int __weak __init reserve_bootmem_generic(unsigned long phys, unsigned long len, int flags){ return reserve_bootmem(phys, len, flags);} static unsigned long __init align_idx(struct bootmem_data *bdata, unsigned long idx, unsigned long step){ unsigned long base = bdata->node_min_pfn; /* * Align the index with respect to the node start so that the * combination of both satisfies the requested alignment. */ return ALIGN(base + idx, step) - base;} static unsigned long __init align_off(struct bootmem_data *bdata, unsigned long off, unsigned long align){ unsigned long base = PFN_PHYS(bdata->node_min_pfn); /* Same as align_idx for byte offsets */ return ALIGN(base + off, align) - base;} static void * __init alloc_bootmem_bdata(struct bootmem_data *bdata, unsigned long size, unsigned long align, unsigned long goal, unsigned long limit){ unsigned long fallback = 0; unsigned long min, max, start, sidx, midx, step; bdebug("nid=%td size=%lx [%lu pages] align=%lx goal=%lx limit=%lx\n", bdata - bootmem_node_data, size, PAGE_ALIGN(size) >> PAGE_SHIFT, align, goal, limit); BUG_ON(!size); BUG_ON(align & (align - 1)); BUG_ON(limit && goal + size > limit); if (!bdata->node_bootmem_map) return NULL; min = bdata->node_min_pfn; max = bdata->node_low_pfn; goal >>= PAGE_SHIFT; limit >>= PAGE_SHIFT; if (limit && max > limit) max = limit; if (max <= min) return NULL; step = max(align >> PAGE_SHIFT, 1UL);Lines 1–500 of 852. 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/* * bootmem - A boot-time physical memory allocator and configurator * * Copyright (C) 1999 Ingo Molnar * 1999 Kanoj Sarcar, SGI * 2008 Johannes Weiner * * Access to this subsystem has to be serialized externally (which is true * for the boot process anyway). */ #include <linux/init.h> #include <linux/pfn.h> #include <linux/slab.h> #include <linux/bootmem.h> #include <linux/export.h> #include <linux/kmemleak.h> #include <linux/range.h> #include <linux/memblock.h> #include <asm/bug.h> #include <asm/io.h> #include <asm/processor.h> #include "internal.h" #ifndef CONFIG_NEED_MULTIPLE_NODES struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] }; EXPORT_SYMBOL(contig_page_data); #endif unsigned long max_low_pfn; unsigned long min_low_pfn; unsigned long max_pfn; bootmem_data_t bootmem_node_data[MAX_NUMNODES] __initdata; static struct list_head bdata_list __initdata = LIST_HEAD_INIT(bdata_list); static int bootmem_debug; static int __init bootmem_debug_setup(char *buf) { bootmem_debug = 1; return 0; } early_param("bootmem_debug", bootmem_debug_setup); #define bdebug(fmt, args...) ({ \ if (unlikely(bootmem_debug)) \ printk(KERN_INFO \ "bootmem::%s " fmt, \ __func__, ## args); \ }) static unsigned long __init bootmap_bytes(unsigned long pages) { unsigned long bytes = DIV_ROUND_UP(pages, 8); return ALIGN(bytes, sizeof(long)); } /** * bootmem_bootmap_pages - calculate bitmap size in pages * @pages: number of pages the bitmap has to represent */ unsigned long __init bootmem_bootmap_pages(unsigned long pages) { unsigned long bytes = bootmap_bytes(pages); return PAGE_ALIGN(bytes) >> PAGE_SHIFT; } /* * link bdata in order */ static void __init link_bootmem(bootmem_data_t *bdata) { bootmem_data_t *ent; list_for_each_entry(ent, &bdata_list, list) { if (bdata->node_min_pfn < ent->node_min_pfn) { list_add_tail(&bdata->list, &ent->list); return; } } list_add_tail(&bdata->list, &bdata_list); } /* * Called once to set up the allocator itself. */ static unsigned long __init init_bootmem_core(bootmem_data_t *bdata, unsigned long mapstart, unsigned long start, unsigned long end) { unsigned long mapsize; mminit_validate_memmodel_limits(&start, &end); bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart)); bdata->node_min_pfn = start; bdata->node_low_pfn = end; link_bootmem(bdata); /* * Initially all pages are reserved - setup_arch() has to * register free RAM areas explicitly. */ mapsize = bootmap_bytes(end - start); memset(bdata->node_bootmem_map, 0xff, mapsize); bdebug("nid=%td start=%lx map=%lx end=%lx mapsize=%lx\n", bdata - bootmem_node_data, start, mapstart, end, mapsize); return mapsize; } /** * init_bootmem_node - register a node as boot memory * @pgdat: node to register * @freepfn: pfn where the bitmap for this node is to be placed * @startpfn: first pfn on the node * @endpfn: first pfn after the node * * Returns the number of bytes needed to hold the bitmap for this node. */ unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn, unsigned long startpfn, unsigned long endpfn) { return init_bootmem_core(pgdat->bdata, freepfn, startpfn, endpfn); } /** * init_bootmem - register boot memory * @start: pfn where the bitmap is to be placed * @pages: number of available physical pages * * Returns the number of bytes needed to hold the bitmap. */ unsigned long __init init_bootmem(unsigned long start, unsigned long pages) { max_low_pfn = pages; min_low_pfn = start; return init_bootmem_core(NODE_DATA(0)->bdata, start, 0, pages); } /* * free_bootmem_late - free bootmem pages directly to page allocator * @addr: starting address of the range * @size: size of the range in bytes * * This is only useful when the bootmem allocator has already been torn * down, but we are still initializing the system. Pages are given directly * to the page allocator, no bootmem metadata is updated because it is gone. */ void __init free_bootmem_late(unsigned long addr, unsigned long size) { unsigned long cursor, end; kmemleak_free_part(__va(addr), size); cursor = PFN_UP(addr); end = PFN_DOWN(addr + size); for (; cursor < end; cursor++) { __free_pages_bootmem(pfn_to_page(cursor), 0); totalram_pages++; } } static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata) { struct page *page; unsigned long start, end, pages, count = 0; if (!bdata->node_bootmem_map) return 0; start = bdata->node_min_pfn; end = bdata->node_low_pfn; bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data, start, end); while (start < end) { unsigned long *map, idx, vec; map = bdata->node_bootmem_map; idx = start - bdata->node_min_pfn; vec = ~map[idx / BITS_PER_LONG]; /* * If we have a properly aligned and fully unreserved * BITS_PER_LONG block of pages in front of us, free * it in one go. */ if (IS_ALIGNED(start, BITS_PER_LONG) && vec == ~0UL) { int order = ilog2(BITS_PER_LONG); __free_pages_bootmem(pfn_to_page(start), order); count += BITS_PER_LONG; start += BITS_PER_LONG; } else { unsigned long off = 0; vec >>= start & (BITS_PER_LONG - 1); while (vec) { if (vec & 1) { page = pfn_to_page(start + off); __free_pages_bootmem(page, 0); count++; } vec >>= 1; off++; } start = ALIGN(start + 1, BITS_PER_LONG); } } page = virt_to_page(bdata->node_bootmem_map); pages = bdata->node_low_pfn - bdata->node_min_pfn; pages = bootmem_bootmap_pages(pages); count += pages; while (pages--) __free_pages_bootmem(page++, 0); bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count); return count; } /** * free_all_bootmem_node - release a node's free pages to the buddy allocator * @pgdat: node to be released * * Returns the number of pages actually released. */ unsigned long __init free_all_bootmem_node(pg_data_t *pgdat) { register_page_bootmem_info_node(pgdat); return free_all_bootmem_core(pgdat->bdata); } /** * free_all_bootmem - release free pages to the buddy allocator * * Returns the number of pages actually released. */ unsigned long __init free_all_bootmem(void) { unsigned long total_pages = 0; bootmem_data_t *bdata; list_for_each_entry(bdata, &bdata_list, list) total_pages += free_all_bootmem_core(bdata); return total_pages; } static void __init __free(bootmem_data_t *bdata, unsigned long sidx, unsigned long eidx) { unsigned long idx; bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data, sidx + bdata->node_min_pfn, eidx + bdata->node_min_pfn); if (bdata->hint_idx > sidx) bdata->hint_idx = sidx; for (idx = sidx; idx < eidx; idx++) if (!test_and_clear_bit(idx, bdata->node_bootmem_map)) BUG(); } static int __init __reserve(bootmem_data_t *bdata, unsigned long sidx, unsigned long eidx, int flags) { unsigned long idx; int exclusive = flags & BOOTMEM_EXCLUSIVE; bdebug("nid=%td start=%lx end=%lx flags=%x\n", bdata - bootmem_node_data, sidx + bdata->node_min_pfn, eidx + bdata->node_min_pfn, flags); for (idx = sidx; idx < eidx; idx++) if (test_and_set_bit(idx, bdata->node_bootmem_map)) { if (exclusive) { __free(bdata, sidx, idx); return -EBUSY; } bdebug("silent double reserve of PFN %lx\n", idx + bdata->node_min_pfn); } return 0; } static int __init mark_bootmem_node(bootmem_data_t *bdata, unsigned long start, unsigned long end, int reserve, int flags) { unsigned long sidx, eidx; bdebug("nid=%td start=%lx end=%lx reserve=%d flags=%x\n", bdata - bootmem_node_data, start, end, reserve, flags); BUG_ON(start < bdata->node_min_pfn); BUG_ON(end > bdata->node_low_pfn); sidx = start - bdata->node_min_pfn; eidx = end - bdata->node_min_pfn; if (reserve) return __reserve(bdata, sidx, eidx, flags); else __free(bdata, sidx, eidx); return 0; } static int __init mark_bootmem(unsigned long start, unsigned long end, int reserve, int flags) { unsigned long pos; bootmem_data_t *bdata; pos = start; list_for_each_entry(bdata, &bdata_list, list) { int err; unsigned long max; if (pos < bdata->node_min_pfn || pos >= bdata->node_low_pfn) { BUG_ON(pos != start); continue; } max = min(bdata->node_low_pfn, end); err = mark_bootmem_node(bdata, pos, max, reserve, flags); if (reserve && err) { mark_bootmem(start, pos, 0, 0); return err; } if (max == end) return 0; pos = bdata->node_low_pfn; } BUG(); } /** * free_bootmem_node - mark a page range as usable * @pgdat: node the range resides on * @physaddr: starting address of the range * @size: size of the range in bytes * * Partial pages will be considered reserved and left as they are. * * The range must reside completely on the specified node. */ void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr, unsigned long size) { unsigned long start, end; kmemleak_free_part(__va(physaddr), size); start = PFN_UP(physaddr); end = PFN_DOWN(physaddr + size); mark_bootmem_node(pgdat->bdata, start, end, 0, 0); } /** * free_bootmem - mark a page range as usable * @addr: starting address of the range * @size: size of the range in bytes * * Partial pages will be considered reserved and left as they are. * * The range must be contiguous but may span node boundaries. */ void __init free_bootmem(unsigned long addr, unsigned long size) { unsigned long start, end; kmemleak_free_part(__va(addr), size); start = PFN_UP(addr); end = PFN_DOWN(addr + size); mark_bootmem(start, end, 0, 0); } /** * reserve_bootmem_node - mark a page range as reserved * @pgdat: node the range resides on * @physaddr: starting address of the range * @size: size of the range in bytes * @flags: reservation flags (see linux/bootmem.h) * * Partial pages will be reserved. * * The range must reside completely on the specified node. */ int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr, unsigned long size, int flags) { unsigned long start, end; start = PFN_DOWN(physaddr); end = PFN_UP(physaddr + size); return mark_bootmem_node(pgdat->bdata, start, end, 1, flags); } /** * reserve_bootmem - mark a page range as usable * @addr: starting address of the range * @size: size of the range in bytes * @flags: reservation flags (see linux/bootmem.h) * * Partial pages will be reserved. * * The range must be contiguous but may span node boundaries. */ int __init reserve_bootmem(unsigned long addr, unsigned long size, int flags) { unsigned long start, end; start = PFN_DOWN(addr); end = PFN_UP(addr + size); return mark_bootmem(start, end, 1, flags); } int __weak __init reserve_bootmem_generic(unsigned long phys, unsigned long len, int flags) { return reserve_bootmem(phys, len, flags); } static unsigned long __init align_idx(struct bootmem_data *bdata, unsigned long idx, unsigned long step) { unsigned long base = bdata->node_min_pfn; /* * Align the index with respect to the node start so that the * combination of both satisfies the requested alignment. */ return ALIGN(base + idx, step) - base; } static unsigned long __init align_off(struct bootmem_data *bdata, unsigned long off, unsigned long align) { unsigned long base = PFN_PHYS(bdata->node_min_pfn); /* Same as align_idx for byte offsets */ return ALIGN(base + off, align) - base; } static void * __init alloc_bootmem_bdata(struct bootmem_data *bdata, unsigned long size, unsigned long align, unsigned long goal, unsigned long limit) { unsigned long fallback = 0; unsigned long min, max, start, sidx, midx, step; bdebug("nid=%td size=%lx [%lu pages] align=%lx goal=%lx limit=%lx\n", bdata - bootmem_node_data, size, PAGE_ALIGN(size) >> PAGE_SHIFT, align, goal, limit); BUG_ON(!size); BUG_ON(align & (align - 1)); BUG_ON(limit && goal + size > limit); if (!bdata->node_bootmem_map) return NULL; min = bdata->node_min_pfn; max = bdata->node_low_pfn; goal >>= PAGE_SHIFT; limit >>= PAGE_SHIFT; if (limit && max > limit) max = limit; if (max <= min) return NULL; step = max(align >> PAGE_SHIFT, 1UL);