config: tegra3: enable /dev mount with ACL
[linux-2.6.git] / mm / sparse-vmemmap.c
1 /*
2  * Virtual Memory Map support
3  *
4  * (C) 2007 sgi. Christoph Lameter.
5  *
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 memory 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  *
17  * The architecture is expected to provide a vmemmap_populate() function
18  * to instantiate the mapping.
19  */
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/slab.h>
26 #include <linux/spinlock.h>
27 #include <linux/vmalloc.h>
28 #include <linux/sched.h>
29 #include <asm/dma.h>
30 #include <asm/pgalloc.h>
31 #include <asm/pgtable.h>
32
33 /*
34  * Allocate a block of memory to be used to back the virtual memory map
35  * or to back the page tables that are used to create the mapping.
36  * Uses the main allocators if they are available, else bootmem.
37  */
38
39 static void * __init_refok __earlyonly_bootmem_alloc(int node,
40                                 unsigned long size,
41                                 unsigned long align,
42                                 unsigned long goal)
43 {
44         return __alloc_bootmem_node_high(NODE_DATA(node), size, align, goal);
45 }
46
47 static void *vmemmap_buf;
48 static void *vmemmap_buf_end;
49
50 void * __meminit vmemmap_alloc_block(unsigned long size, int node)
51 {
52         /* If the main allocator is up use that, fallback to bootmem. */
53         if (slab_is_available()) {
54                 struct page *page;
55
56                 if (node_state(node, N_HIGH_MEMORY))
57                         page = alloc_pages_node(node,
58                                 GFP_KERNEL | __GFP_ZERO, get_order(size));
59                 else
60                         page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
61                                 get_order(size));
62                 if (page)
63                         return page_address(page);
64                 return NULL;
65         } else
66                 return __earlyonly_bootmem_alloc(node, size, size,
67                                 __pa(MAX_DMA_ADDRESS));
68 }
69
70 /* need to make sure size is all the same during early stage */
71 void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node)
72 {
73         void *ptr;
74
75         if (!vmemmap_buf)
76                 return vmemmap_alloc_block(size, node);
77
78         /* take the from buf */
79         ptr = (void *)ALIGN((unsigned long)vmemmap_buf, size);
80         if (ptr + size > vmemmap_buf_end)
81                 return vmemmap_alloc_block(size, node);
82
83         vmemmap_buf = ptr + size;
84
85         return ptr;
86 }
87
88 void __meminit vmemmap_verify(pte_t *pte, int node,
89                                 unsigned long start, unsigned long end)
90 {
91         unsigned long pfn = pte_pfn(*pte);
92         int actual_node = early_pfn_to_nid(pfn);
93
94         if (node_distance(actual_node, node) > LOCAL_DISTANCE)
95                 printk(KERN_WARNING "[%lx-%lx] potential offnode "
96                         "page_structs\n", start, end - 1);
97 }
98
99 pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node)
100 {
101         pte_t *pte = pte_offset_kernel(pmd, addr);
102         if (pte_none(*pte)) {
103                 pte_t entry;
104                 void *p = vmemmap_alloc_block_buf(PAGE_SIZE, node);
105                 if (!p)
106                         return NULL;
107                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
108                 set_pte_at(&init_mm, addr, pte, entry);
109         }
110         return pte;
111 }
112
113 pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
114 {
115         pmd_t *pmd = pmd_offset(pud, addr);
116         if (pmd_none(*pmd)) {
117                 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
118                 if (!p)
119                         return NULL;
120                 pmd_populate_kernel(&init_mm, pmd, p);
121         }
122         return pmd;
123 }
124
125 pud_t * __meminit vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node)
126 {
127         pud_t *pud = pud_offset(pgd, addr);
128         if (pud_none(*pud)) {
129                 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
130                 if (!p)
131                         return NULL;
132                 pud_populate(&init_mm, pud, p);
133         }
134         return pud;
135 }
136
137 pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
138 {
139         pgd_t *pgd = pgd_offset_k(addr);
140         if (pgd_none(*pgd)) {
141                 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
142                 if (!p)
143                         return NULL;
144                 pgd_populate(&init_mm, pgd, p);
145         }
146         return pgd;
147 }
148
149 int __meminit vmemmap_populate_basepages(struct page *start_page,
150                                                 unsigned long size, int node)
151 {
152         unsigned long addr = (unsigned long)start_page;
153         unsigned long end = (unsigned long)(start_page + size);
154         pgd_t *pgd;
155         pud_t *pud;
156         pmd_t *pmd;
157         pte_t *pte;
158
159         for (; addr < end; addr += PAGE_SIZE) {
160                 pgd = vmemmap_pgd_populate(addr, node);
161                 if (!pgd)
162                         return -ENOMEM;
163                 pud = vmemmap_pud_populate(pgd, addr, node);
164                 if (!pud)
165                         return -ENOMEM;
166                 pmd = vmemmap_pmd_populate(pud, addr, node);
167                 if (!pmd)
168                         return -ENOMEM;
169                 pte = vmemmap_pte_populate(pmd, addr, node);
170                 if (!pte)
171                         return -ENOMEM;
172                 vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
173         }
174
175         return 0;
176 }
177
178 struct page * __meminit sparse_mem_map_populate(unsigned long pnum, int nid)
179 {
180         struct page *map = pfn_to_page(pnum * PAGES_PER_SECTION);
181         int error = vmemmap_populate(map, PAGES_PER_SECTION, nid);
182         if (error)
183                 return NULL;
184
185         return map;
186 }
187
188 void __init sparse_mem_maps_populate_node(struct page **map_map,
189                                           unsigned long pnum_begin,
190                                           unsigned long pnum_end,
191                                           unsigned long map_count, int nodeid)
192 {
193         unsigned long pnum;
194         unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
195         void *vmemmap_buf_start;
196
197         size = ALIGN(size, PMD_SIZE);
198         vmemmap_buf_start = __earlyonly_bootmem_alloc(nodeid, size * map_count,
199                          PMD_SIZE, __pa(MAX_DMA_ADDRESS));
200
201         if (vmemmap_buf_start) {
202                 vmemmap_buf = vmemmap_buf_start;
203                 vmemmap_buf_end = vmemmap_buf_start + size * map_count;
204         }
205
206         for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
207                 struct mem_section *ms;
208
209                 if (!present_section_nr(pnum))
210                         continue;
211
212                 map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
213                 if (map_map[pnum])
214                         continue;
215                 ms = __nr_to_section(pnum);
216                 printk(KERN_ERR "%s: sparsemem memory map backing failed "
217                         "some memory will not be available.\n", __func__);
218                 ms->section_mem_map = 0;
219         }
220
221         if (vmemmap_buf_start) {
222                 /* need to free left buf */
223                 free_bootmem(__pa(vmemmap_buf), vmemmap_buf_end - vmemmap_buf);
224                 vmemmap_buf = NULL;
225                 vmemmap_buf_end = NULL;
226         }
227 }