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Merge tag 'v3.14-rc1' into patchwork
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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 memblock_virt_alloc_try_nid(size, align, goal,
44                                             BOOTMEM_ALLOC_ACCESSIBLE, node);
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(
58                                 node, GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT,
59                                 get_order(size));
60                 else
61                         page = alloc_pages(
62                                 GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT,
63                                 get_order(size));
64                 if (page)
65                         return page_address(page);
66                 return NULL;
67         } else
68                 return __earlyonly_bootmem_alloc(node, size, size,
69                                 __pa(MAX_DMA_ADDRESS));
70 }
71
72 /* need to make sure size is all the same during early stage */
73 void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node)
74 {
75         void *ptr;
76
77         if (!vmemmap_buf)
78                 return vmemmap_alloc_block(size, node);
79
80         /* take the from buf */
81         ptr = (void *)ALIGN((unsigned long)vmemmap_buf, size);
82         if (ptr + size > vmemmap_buf_end)
83                 return vmemmap_alloc_block(size, node);
84
85         vmemmap_buf = ptr + size;
86
87         return ptr;
88 }
89
90 void __meminit vmemmap_verify(pte_t *pte, int node,
91                                 unsigned long start, unsigned long end)
92 {
93         unsigned long pfn = pte_pfn(*pte);
94         int actual_node = early_pfn_to_nid(pfn);
95
96         if (node_distance(actual_node, node) > LOCAL_DISTANCE)
97                 printk(KERN_WARNING "[%lx-%lx] potential offnode "
98                         "page_structs\n", start, end - 1);
99 }
100
101 pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node)
102 {
103         pte_t *pte = pte_offset_kernel(pmd, addr);
104         if (pte_none(*pte)) {
105                 pte_t entry;
106                 void *p = vmemmap_alloc_block_buf(PAGE_SIZE, node);
107                 if (!p)
108                         return NULL;
109                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
110                 set_pte_at(&init_mm, addr, pte, entry);
111         }
112         return pte;
113 }
114
115 pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
116 {
117         pmd_t *pmd = pmd_offset(pud, addr);
118         if (pmd_none(*pmd)) {
119                 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
120                 if (!p)
121                         return NULL;
122                 pmd_populate_kernel(&init_mm, pmd, p);
123         }
124         return pmd;
125 }
126
127 pud_t * __meminit vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node)
128 {
129         pud_t *pud = pud_offset(pgd, addr);
130         if (pud_none(*pud)) {
131                 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
132                 if (!p)
133                         return NULL;
134                 pud_populate(&init_mm, pud, p);
135         }
136         return pud;
137 }
138
139 pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
140 {
141         pgd_t *pgd = pgd_offset_k(addr);
142         if (pgd_none(*pgd)) {
143                 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
144                 if (!p)
145                         return NULL;
146                 pgd_populate(&init_mm, pgd, p);
147         }
148         return pgd;
149 }
150
151 int __meminit vmemmap_populate_basepages(unsigned long start,
152                                          unsigned long end, int node)
153 {
154         unsigned long addr = start;
155         pgd_t *pgd;
156         pud_t *pud;
157         pmd_t *pmd;
158         pte_t *pte;
159
160         for (; addr < end; addr += PAGE_SIZE) {
161                 pgd = vmemmap_pgd_populate(addr, node);
162                 if (!pgd)
163                         return -ENOMEM;
164                 pud = vmemmap_pud_populate(pgd, addr, node);
165                 if (!pud)
166                         return -ENOMEM;
167                 pmd = vmemmap_pmd_populate(pud, addr, node);
168                 if (!pmd)
169                         return -ENOMEM;
170                 pte = vmemmap_pte_populate(pmd, addr, node);
171                 if (!pte)
172                         return -ENOMEM;
173                 vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
174         }
175
176         return 0;
177 }
178
179 struct page * __meminit sparse_mem_map_populate(unsigned long pnum, int nid)
180 {
181         unsigned long start;
182         unsigned long end;
183         struct page *map;
184
185         map = pfn_to_page(pnum * PAGES_PER_SECTION);
186         start = (unsigned long)map;
187         end = (unsigned long)(map + PAGES_PER_SECTION);
188
189         if (vmemmap_populate(start, end, nid))
190                 return NULL;
191
192         return map;
193 }
194
195 void __init sparse_mem_maps_populate_node(struct page **map_map,
196                                           unsigned long pnum_begin,
197                                           unsigned long pnum_end,
198                                           unsigned long map_count, int nodeid)
199 {
200         unsigned long pnum;
201         unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
202         void *vmemmap_buf_start;
203
204         size = ALIGN(size, PMD_SIZE);
205         vmemmap_buf_start = __earlyonly_bootmem_alloc(nodeid, size * map_count,
206                          PMD_SIZE, __pa(MAX_DMA_ADDRESS));
207
208         if (vmemmap_buf_start) {
209                 vmemmap_buf = vmemmap_buf_start;
210                 vmemmap_buf_end = vmemmap_buf_start + size * map_count;
211         }
212
213         for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
214                 struct mem_section *ms;
215
216                 if (!present_section_nr(pnum))
217                         continue;
218
219                 map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
220                 if (map_map[pnum])
221                         continue;
222                 ms = __nr_to_section(pnum);
223                 printk(KERN_ERR "%s: sparsemem memory map backing failed "
224                         "some memory will not be available.\n", __func__);
225                 ms->section_mem_map = 0;
226         }
227
228         if (vmemmap_buf_start) {
229                 /* need to free left buf */
230                 memblock_free_early(__pa(vmemmap_buf),
231                                     vmemmap_buf_end - vmemmap_buf);
232                 vmemmap_buf = NULL;
233                 vmemmap_buf_end = NULL;
234         }
235 }