ARM: tegra: pm269: sdhci: Support for PM269
[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/slab.h>
25 #include <linux/spinlock.h>
26 #include <linux/vmalloc.h>
27 #include <linux/sched.h>
28 #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  */
37
38 static 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_high(NODE_DATA(node), size, align, goal);
44 }
45
46 static void *vmemmap_buf;
47 static void *vmemmap_buf_end;
48
49 void * __meminit vmemmap_alloc_block(unsigned long size, int node)
50 {
51         /* If the main allocator is up use that, fallback to bootmem. */
52         if (slab_is_available()) {
53                 struct page *page;
54
55                 if (node_state(node, N_HIGH_MEMORY))
56                         page = alloc_pages_node(node,
57                                 GFP_KERNEL | __GFP_ZERO, get_order(size));
58                 else
59                         page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
60                                 get_order(size));
61                 if (page)
62                         return page_address(page);
63                 return NULL;
64         } else
65                 return __earlyonly_bootmem_alloc(node, size, size,
66                                 __pa(MAX_DMA_ADDRESS));
67 }
68
69 /* need to make sure size is all the same during early stage */
70 void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node)
71 {
72         void *ptr;
73
74         if (!vmemmap_buf)
75                 return vmemmap_alloc_block(size, node);
76
77         /* take the from buf */
78         ptr = (void *)ALIGN((unsigned long)vmemmap_buf, size);
79         if (ptr + size > vmemmap_buf_end)
80                 return vmemmap_alloc_block(size, node);
81
82         vmemmap_buf = ptr + size;
83
84         return ptr;
85 }
86
87 void __meminit vmemmap_verify(pte_t *pte, int node,
88                                 unsigned long start, unsigned long end)
89 {
90         unsigned long pfn = pte_pfn(*pte);
91         int actual_node = early_pfn_to_nid(pfn);
92
93         if (node_distance(actual_node, node) > LOCAL_DISTANCE)
94                 printk(KERN_WARNING "[%lx-%lx] potential offnode "
95                         "page_structs\n", start, end - 1);
96 }
97
98 pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node)
99 {
100         pte_t *pte = pte_offset_kernel(pmd, addr);
101         if (pte_none(*pte)) {
102                 pte_t entry;
103                 void *p = vmemmap_alloc_block_buf(PAGE_SIZE, node);
104                 if (!p)
105                         return NULL;
106                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
107                 set_pte_at(&init_mm, addr, pte, entry);
108         }
109         return pte;
110 }
111
112 pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
113 {
114         pmd_t *pmd = pmd_offset(pud, addr);
115         if (pmd_none(*pmd)) {
116                 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
117                 if (!p)
118                         return NULL;
119                 pmd_populate_kernel(&init_mm, pmd, p);
120         }
121         return pmd;
122 }
123
124 pud_t * __meminit vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node)
125 {
126         pud_t *pud = pud_offset(pgd, addr);
127         if (pud_none(*pud)) {
128                 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
129                 if (!p)
130                         return NULL;
131                 pud_populate(&init_mm, pud, p);
132         }
133         return pud;
134 }
135
136 pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
137 {
138         pgd_t *pgd = pgd_offset_k(addr);
139         if (pgd_none(*pgd)) {
140                 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
141                 if (!p)
142                         return NULL;
143                 pgd_populate(&init_mm, pgd, p);
144         }
145         return pgd;
146 }
147
148 int __meminit vmemmap_populate_basepages(struct page *start_page,
149                                                 unsigned long size, int node)
150 {
151         unsigned long addr = (unsigned long)start_page;
152         unsigned long end = (unsigned long)(start_page + size);
153         pgd_t *pgd;
154         pud_t *pud;
155         pmd_t *pmd;
156         pte_t *pte;
157
158         for (; addr < end; addr += PAGE_SIZE) {
159                 pgd = vmemmap_pgd_populate(addr, node);
160                 if (!pgd)
161                         return -ENOMEM;
162                 pud = vmemmap_pud_populate(pgd, addr, node);
163                 if (!pud)
164                         return -ENOMEM;
165                 pmd = vmemmap_pmd_populate(pud, addr, node);
166                 if (!pmd)
167                         return -ENOMEM;
168                 pte = vmemmap_pte_populate(pmd, addr, node);
169                 if (!pte)
170                         return -ENOMEM;
171                 vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
172         }
173
174         return 0;
175 }
176
177 struct page * __meminit sparse_mem_map_populate(unsigned long pnum, int nid)
178 {
179         struct page *map = pfn_to_page(pnum * PAGES_PER_SECTION);
180         int error = vmemmap_populate(map, PAGES_PER_SECTION, nid);
181         if (error)
182                 return NULL;
183
184         return map;
185 }
186
187 void __init sparse_mem_maps_populate_node(struct page **map_map,
188                                           unsigned long pnum_begin,
189                                           unsigned long pnum_end,
190                                           unsigned long map_count, int nodeid)
191 {
192         unsigned long pnum;
193         unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
194         void *vmemmap_buf_start;
195
196         size = ALIGN(size, PMD_SIZE);
197         vmemmap_buf_start = __earlyonly_bootmem_alloc(nodeid, size * map_count,
198                          PMD_SIZE, __pa(MAX_DMA_ADDRESS));
199
200         if (vmemmap_buf_start) {
201                 vmemmap_buf = vmemmap_buf_start;
202                 vmemmap_buf_end = vmemmap_buf_start + size * map_count;
203         }
204
205         for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
206                 struct mem_section *ms;
207
208                 if (!present_section_nr(pnum))
209                         continue;
210
211                 map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
212                 if (map_map[pnum])
213                         continue;
214                 ms = __nr_to_section(pnum);
215                 printk(KERN_ERR "%s: sparsemem memory map backing failed "
216                         "some memory will not be available.\n", __func__);
217                 ms->section_mem_map = 0;
218         }
219
220         if (vmemmap_buf_start) {
221                 /* need to free left buf */
222                 free_bootmem(__pa(vmemmap_buf), vmemmap_buf_end - vmemmap_buf);
223                 vmemmap_buf = NULL;
224                 vmemmap_buf_end = NULL;
225         }
226 }