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Christoph Lameter8f6aac42007-10-16 01:24:13 -07001/*
2 * Virtual Memory Map support
3 *
Christoph Lametercde53532008-07-04 09:59:22 -07004 * (C) 2007 sgi. Christoph Lameter.
Christoph Lameter8f6aac42007-10-16 01:24:13 -07005 *
6 * Virtual memory maps allow VM primitives pfn_to_page, page_to_pfn,
7 * virt_to_page, page_address() to be implemented as a base offset
8 * calculation without memory access.
9 *
10 * However, virtual mappings need a page table and TLBs. Many Linux
11 * architectures already map their physical space using 1-1 mappings
12 * via TLBs. For those arches the virtual memmory map is essentially
13 * for free if we use the same page size as the 1-1 mappings. In that
14 * case the overhead consists of a few additional pages that are
15 * allocated to create a view of memory for vmemmap.
16 *
Andy Whitcroft29c71112007-10-16 01:24:14 -070017 * The architecture is expected to provide a vmemmap_populate() function
18 * to instantiate the mapping.
Christoph Lameter8f6aac42007-10-16 01:24:13 -070019 */
20#include <linux/mm.h>
21#include <linux/mmzone.h>
22#include <linux/bootmem.h>
23#include <linux/highmem.h>
24#include <linux/module.h>
25#include <linux/spinlock.h>
26#include <linux/vmalloc.h>
Glauber de Oliveira Costa8bca44b2007-10-29 14:37:19 -070027#include <linux/sched.h>
Christoph Lameter8f6aac42007-10-16 01:24:13 -070028#include <asm/dma.h>
29#include <asm/pgalloc.h>
30#include <asm/pgtable.h>
31
32/*
33 * Allocate a block of memory to be used to back the virtual memory map
34 * or to back the page tables that are used to create the mapping.
35 * Uses the main allocators if they are available, else bootmem.
36 */
KAMEZAWA Hiroyukie0dc3a52007-11-28 16:21:57 -080037
38static void * __init_refok __earlyonly_bootmem_alloc(int node,
39 unsigned long size,
40 unsigned long align,
41 unsigned long goal)
42{
43 return __alloc_bootmem_node(NODE_DATA(node), size, align, goal);
44}
45
46
Christoph Lameter8f6aac42007-10-16 01:24:13 -070047void * __meminit vmemmap_alloc_block(unsigned long size, int node)
48{
49 /* If the main allocator is up use that, fallback to bootmem. */
50 if (slab_is_available()) {
Shaohua Lif52407c2009-09-21 17:01:19 -070051 struct page *page;
52
53 if (node_state(node, N_HIGH_MEMORY))
54 page = alloc_pages_node(node,
Christoph Lameter8f6aac42007-10-16 01:24:13 -070055 GFP_KERNEL | __GFP_ZERO, get_order(size));
Shaohua Lif52407c2009-09-21 17:01:19 -070056 else
57 page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
58 get_order(size));
Christoph Lameter8f6aac42007-10-16 01:24:13 -070059 if (page)
60 return page_address(page);
61 return NULL;
62 } else
KAMEZAWA Hiroyukie0dc3a52007-11-28 16:21:57 -080063 return __earlyonly_bootmem_alloc(node, size, size,
Christoph Lameter8f6aac42007-10-16 01:24:13 -070064 __pa(MAX_DMA_ADDRESS));
65}
66
Christoph Lameter8f6aac42007-10-16 01:24:13 -070067void __meminit vmemmap_verify(pte_t *pte, int node,
68 unsigned long start, unsigned long end)
69{
70 unsigned long pfn = pte_pfn(*pte);
71 int actual_node = early_pfn_to_nid(pfn);
72
David Rientjesb41ad142008-11-06 12:53:31 -080073 if (node_distance(actual_node, node) > LOCAL_DISTANCE)
Christoph Lameter8f6aac42007-10-16 01:24:13 -070074 printk(KERN_WARNING "[%lx-%lx] potential offnode "
75 "page_structs\n", start, end - 1);
76}
77
Andy Whitcroft29c71112007-10-16 01:24:14 -070078pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node)
Christoph Lameter8f6aac42007-10-16 01:24:13 -070079{
Andy Whitcroft29c71112007-10-16 01:24:14 -070080 pte_t *pte = pte_offset_kernel(pmd, addr);
81 if (pte_none(*pte)) {
82 pte_t entry;
83 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
84 if (!p)
Al Viro9dce07f2008-03-29 03:07:28 +000085 return NULL;
Andy Whitcroft29c71112007-10-16 01:24:14 -070086 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
87 set_pte_at(&init_mm, addr, pte, entry);
88 }
89 return pte;
90}
91
92pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
93{
94 pmd_t *pmd = pmd_offset(pud, addr);
95 if (pmd_none(*pmd)) {
96 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
97 if (!p)
Al Viro9dce07f2008-03-29 03:07:28 +000098 return NULL;
Andy Whitcroft29c71112007-10-16 01:24:14 -070099 pmd_populate_kernel(&init_mm, pmd, p);
100 }
101 return pmd;
102}
103
104pud_t * __meminit vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node)
105{
106 pud_t *pud = pud_offset(pgd, addr);
107 if (pud_none(*pud)) {
108 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
109 if (!p)
Al Viro9dce07f2008-03-29 03:07:28 +0000110 return NULL;
Andy Whitcroft29c71112007-10-16 01:24:14 -0700111 pud_populate(&init_mm, pud, p);
112 }
113 return pud;
114}
115
116pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
117{
118 pgd_t *pgd = pgd_offset_k(addr);
119 if (pgd_none(*pgd)) {
120 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
121 if (!p)
Al Viro9dce07f2008-03-29 03:07:28 +0000122 return NULL;
Andy Whitcroft29c71112007-10-16 01:24:14 -0700123 pgd_populate(&init_mm, pgd, p);
124 }
125 return pgd;
126}
127
128int __meminit vmemmap_populate_basepages(struct page *start_page,
129 unsigned long size, int node)
130{
131 unsigned long addr = (unsigned long)start_page;
132 unsigned long end = (unsigned long)(start_page + size);
133 pgd_t *pgd;
134 pud_t *pud;
135 pmd_t *pmd;
Christoph Lameter8f6aac42007-10-16 01:24:13 -0700136 pte_t *pte;
137
Andy Whitcroft29c71112007-10-16 01:24:14 -0700138 for (; addr < end; addr += PAGE_SIZE) {
139 pgd = vmemmap_pgd_populate(addr, node);
140 if (!pgd)
141 return -ENOMEM;
142 pud = vmemmap_pud_populate(pgd, addr, node);
143 if (!pud)
144 return -ENOMEM;
145 pmd = vmemmap_pmd_populate(pud, addr, node);
146 if (!pmd)
147 return -ENOMEM;
148 pte = vmemmap_pte_populate(pmd, addr, node);
149 if (!pte)
150 return -ENOMEM;
151 vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
152 }
Christoph Lameter8f6aac42007-10-16 01:24:13 -0700153
154 return 0;
155}
156
Yasunori Goto98f3cfc2007-10-16 01:26:14 -0700157struct page * __meminit sparse_mem_map_populate(unsigned long pnum, int nid)
Christoph Lameter8f6aac42007-10-16 01:24:13 -0700158{
159 struct page *map = pfn_to_page(pnum * PAGES_PER_SECTION);
160 int error = vmemmap_populate(map, PAGES_PER_SECTION, nid);
161 if (error)
162 return NULL;
163
164 return map;
165}