324 lines
8.1 KiB
C
324 lines
8.1 KiB
C
/*
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* Virtual Memory Map support
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*
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* (C) 2007 sgi. Christoph Lameter.
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*
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* Virtual memory maps allow VM primitives pfn_to_page, page_to_pfn,
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* virt_to_page, page_address() to be implemented as a base offset
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* calculation without memory access.
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*
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* However, virtual mappings need a page table and TLBs. Many Linux
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* architectures already map their physical space using 1-1 mappings
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* via TLBs. For those arches the virtual memory map is essentially
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* for free if we use the same page size as the 1-1 mappings. In that
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* case the overhead consists of a few additional pages that are
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* allocated to create a view of memory for vmemmap.
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*
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* The architecture is expected to provide a vmemmap_populate() function
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* to instantiate the mapping.
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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/memremap.h>
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#include <linux/highmem.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/vmalloc.h>
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#include <linux/sched.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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* Allocate a block of memory to be used to back the virtual memory map
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* or to back the page tables that are used to create the mapping.
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* Uses the main allocators if they are available, else bootmem.
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*/
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static void * __ref __earlyonly_bootmem_alloc(int node,
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unsigned long size,
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unsigned long align,
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unsigned long goal)
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{
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return memblock_virt_alloc_try_nid(size, align, goal,
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BOOTMEM_ALLOC_ACCESSIBLE, node);
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}
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static void *vmemmap_buf;
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static void *vmemmap_buf_end;
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void * __meminit vmemmap_alloc_block(unsigned long size, int node)
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{
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/* If the main allocator is up use that, fallback to bootmem. */
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if (slab_is_available()) {
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struct page *page;
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if (node_state(node, N_HIGH_MEMORY))
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page = alloc_pages_node(
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node, GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT,
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get_order(size));
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else
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page = alloc_pages(
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GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT,
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get_order(size));
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if (page)
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return page_address(page);
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return NULL;
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} else
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return __earlyonly_bootmem_alloc(node, size, size,
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__pa(MAX_DMA_ADDRESS));
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}
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/* need to make sure size is all the same during early stage */
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static void * __meminit alloc_block_buf(unsigned long size, int node)
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{
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void *ptr;
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if (!vmemmap_buf)
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return vmemmap_alloc_block(size, node);
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/* take the from buf */
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ptr = (void *)ALIGN((unsigned long)vmemmap_buf, size);
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if (ptr + size > vmemmap_buf_end)
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return vmemmap_alloc_block(size, node);
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vmemmap_buf = ptr + size;
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return ptr;
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}
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static unsigned long __meminit vmem_altmap_next_pfn(struct vmem_altmap *altmap)
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{
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return altmap->base_pfn + altmap->reserve + altmap->alloc
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+ altmap->align;
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}
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static unsigned long __meminit vmem_altmap_nr_free(struct vmem_altmap *altmap)
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{
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unsigned long allocated = altmap->alloc + altmap->align;
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if (altmap->free > allocated)
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return altmap->free - allocated;
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return 0;
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}
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/**
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* vmem_altmap_alloc - allocate pages from the vmem_altmap reservation
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* @altmap - reserved page pool for the allocation
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* @nr_pfns - size (in pages) of the allocation
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*
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* Allocations are aligned to the size of the request
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*/
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static unsigned long __meminit vmem_altmap_alloc(struct vmem_altmap *altmap,
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unsigned long nr_pfns)
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{
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unsigned long pfn = vmem_altmap_next_pfn(altmap);
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unsigned long nr_align;
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nr_align = 1UL << find_first_bit(&nr_pfns, BITS_PER_LONG);
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nr_align = ALIGN(pfn, nr_align) - pfn;
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if (nr_pfns + nr_align > vmem_altmap_nr_free(altmap))
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return ULONG_MAX;
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altmap->alloc += nr_pfns;
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altmap->align += nr_align;
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return pfn + nr_align;
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}
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static void * __meminit altmap_alloc_block_buf(unsigned long size,
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struct vmem_altmap *altmap)
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{
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unsigned long pfn, nr_pfns;
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void *ptr;
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if (size & ~PAGE_MASK) {
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pr_warn_once("%s: allocations must be multiple of PAGE_SIZE (%ld)\n",
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__func__, size);
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return NULL;
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}
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nr_pfns = size >> PAGE_SHIFT;
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pfn = vmem_altmap_alloc(altmap, nr_pfns);
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if (pfn < ULONG_MAX)
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ptr = __va(__pfn_to_phys(pfn));
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else
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ptr = NULL;
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pr_debug("%s: pfn: %#lx alloc: %ld align: %ld nr: %#lx\n",
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__func__, pfn, altmap->alloc, altmap->align, nr_pfns);
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return ptr;
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}
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/* need to make sure size is all the same during early stage */
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void * __meminit __vmemmap_alloc_block_buf(unsigned long size, int node,
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struct vmem_altmap *altmap)
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{
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if (altmap)
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return altmap_alloc_block_buf(size, altmap);
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return alloc_block_buf(size, node);
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}
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void __meminit vmemmap_verify(pte_t *pte, int node,
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unsigned long start, unsigned long end)
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{
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unsigned long pfn = pte_pfn(*pte);
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int actual_node = early_pfn_to_nid(pfn);
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if (node_distance(actual_node, node) > LOCAL_DISTANCE)
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pr_warn("[%lx-%lx] potential offnode page_structs\n",
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start, end - 1);
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}
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pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node)
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{
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pte_t *pte = pte_offset_kernel(pmd, addr);
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if (pte_none(*pte)) {
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pte_t entry;
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void *p = alloc_block_buf(PAGE_SIZE, node);
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if (!p)
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return NULL;
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entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
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set_pte_at(&init_mm, addr, pte, entry);
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}
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return pte;
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}
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pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
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{
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pmd_t *pmd = pmd_offset(pud, addr);
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if (pmd_none(*pmd)) {
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void *p = vmemmap_alloc_block(PAGE_SIZE, node);
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if (!p)
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return NULL;
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pmd_populate_kernel(&init_mm, pmd, p);
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}
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return pmd;
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}
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pud_t * __meminit vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node)
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{
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pud_t *pud = pud_offset(p4d, addr);
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if (pud_none(*pud)) {
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void *p = vmemmap_alloc_block(PAGE_SIZE, node);
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if (!p)
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return NULL;
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pud_populate(&init_mm, pud, p);
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}
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return pud;
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}
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p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node)
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{
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p4d_t *p4d = p4d_offset(pgd, addr);
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if (p4d_none(*p4d)) {
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void *p = vmemmap_alloc_block(PAGE_SIZE, node);
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if (!p)
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return NULL;
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p4d_populate(&init_mm, p4d, p);
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}
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return p4d;
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}
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pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
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{
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pgd_t *pgd = pgd_offset_k(addr);
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if (pgd_none(*pgd)) {
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void *p = vmemmap_alloc_block(PAGE_SIZE, node);
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if (!p)
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return NULL;
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pgd_populate(&init_mm, pgd, p);
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}
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return pgd;
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}
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int __meminit vmemmap_populate_basepages(unsigned long start,
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unsigned long end, int node)
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{
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unsigned long addr = start;
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pgd_t *pgd;
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p4d_t *p4d;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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for (; addr < end; addr += PAGE_SIZE) {
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pgd = vmemmap_pgd_populate(addr, node);
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if (!pgd)
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return -ENOMEM;
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p4d = vmemmap_p4d_populate(pgd, addr, node);
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if (!p4d)
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return -ENOMEM;
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pud = vmemmap_pud_populate(p4d, addr, node);
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if (!pud)
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return -ENOMEM;
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pmd = vmemmap_pmd_populate(pud, addr, node);
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if (!pmd)
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return -ENOMEM;
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pte = vmemmap_pte_populate(pmd, addr, node);
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if (!pte)
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return -ENOMEM;
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vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
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}
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return 0;
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}
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struct page * __meminit sparse_mem_map_populate(unsigned long pnum, int nid)
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{
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unsigned long start;
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unsigned long end;
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struct page *map;
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map = pfn_to_page(pnum * PAGES_PER_SECTION);
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start = (unsigned long)map;
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end = (unsigned long)(map + PAGES_PER_SECTION);
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if (vmemmap_populate(start, end, nid))
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return NULL;
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return map;
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}
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void __init sparse_mem_maps_populate_node(struct page **map_map,
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unsigned long pnum_begin,
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unsigned long pnum_end,
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unsigned long map_count, int nodeid)
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{
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unsigned long pnum;
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unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
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void *vmemmap_buf_start;
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size = ALIGN(size, PMD_SIZE);
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vmemmap_buf_start = __earlyonly_bootmem_alloc(nodeid, size * map_count,
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PMD_SIZE, __pa(MAX_DMA_ADDRESS));
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if (vmemmap_buf_start) {
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vmemmap_buf = vmemmap_buf_start;
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vmemmap_buf_end = vmemmap_buf_start + size * map_count;
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}
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for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
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struct mem_section *ms;
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if (!present_section_nr(pnum))
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continue;
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map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
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if (map_map[pnum])
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continue;
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ms = __nr_to_section(pnum);
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pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
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__func__);
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ms->section_mem_map = 0;
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}
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if (vmemmap_buf_start) {
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/* need to free left buf */
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memblock_free_early(__pa(vmemmap_buf),
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vmemmap_buf_end - vmemmap_buf);
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vmemmap_buf = NULL;
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vmemmap_buf_end = NULL;
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}
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}
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