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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Virtual Memory Map support
4 *
5 * (C) 2007 sgi. Christoph Lameter.
6 *
7 * Virtual memory maps allow VM primitives pfn_to_page, page_to_pfn,
8 * virt_to_page, page_address() to be implemented as a base offset
9 * calculation without memory access.
10 *
11 * However, virtual mappings need a page table and TLBs. Many Linux
12 * architectures already map their physical space using 1-1 mappings
13 * via TLBs. For those arches the virtual memory map is essentially
14 * for free if we use the same page size as the 1-1 mappings. In that
15 * case the overhead consists of a few additional pages that are
16 * allocated to create a view of memory for vmemmap.
17 *
18 * The architecture is expected to provide a vmemmap_populate() function
19 * to instantiate the mapping.
20 */
21#include <linux/mm.h>
22#include <linux/mmzone.h>
23#include <linux/bootmem.h>
24#include <linux/memremap.h>
25#include <linux/highmem.h>
26#include <linux/slab.h>
27#include <linux/spinlock.h>
28#include <linux/vmalloc.h>
29#include <linux/sched.h>
30#include <asm/dma.h>
31#include <asm/pgalloc.h>
32#include <asm/pgtable.h>
33
34/*
35 * Allocate a block of memory to be used to back the virtual memory map
36 * or to back the page tables that are used to create the mapping.
37 * Uses the main allocators if they are available, else bootmem.
38 */
39
40static void * __ref __earlyonly_bootmem_alloc(int node,
41 unsigned long size,
42 unsigned long align,
43 unsigned long goal)
44{
45 return memblock_virt_alloc_try_nid_raw(size, align, goal,
46 BOOTMEM_ALLOC_ACCESSIBLE, node);
47}
48
49static void *vmemmap_buf;
50static void *vmemmap_buf_end;
51
52void * __meminit vmemmap_alloc_block(unsigned long size, int node)
53{
54 /* If the main allocator is up use that, fallback to bootmem. */
55 if (slab_is_available()) {
56 gfp_t gfp_mask = GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_NOWARN;
57 int order = get_order(size);
58 static bool warned;
59 struct page *page;
60
61 page = alloc_pages_node(node, gfp_mask, order);
62 if (page)
63 return page_address(page);
64
65 if (!warned) {
66 warn_alloc(gfp_mask & ~__GFP_NOWARN, NULL,
67 "vmemmap alloc failure: order:%u", order);
68 warned = true;
69 }
70 return NULL;
71 } else
72 return __earlyonly_bootmem_alloc(node, size, size,
73 __pa(MAX_DMA_ADDRESS));
74}
75
76/* need to make sure size is all the same during early stage */
77void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node)
78{
79 void *ptr;
80
81 if (!vmemmap_buf)
82 return vmemmap_alloc_block(size, node);
83
84 /* take the from buf */
85 ptr = (void *)ALIGN((unsigned long)vmemmap_buf, size);
86 if (ptr + size > vmemmap_buf_end)
87 return vmemmap_alloc_block(size, node);
88
89 vmemmap_buf = ptr + size;
90
91 return ptr;
92}
93
94static unsigned long __meminit vmem_altmap_next_pfn(struct vmem_altmap *altmap)
95{
96 return altmap->base_pfn + altmap->reserve + altmap->alloc
97 + altmap->align;
98}
99
100static unsigned long __meminit vmem_altmap_nr_free(struct vmem_altmap *altmap)
101{
102 unsigned long allocated = altmap->alloc + altmap->align;
103
104 if (altmap->free > allocated)
105 return altmap->free - allocated;
106 return 0;
107}
108
109/**
110 * altmap_alloc_block_buf - allocate pages from the device page map
111 * @altmap: device page map
112 * @size: size (in bytes) of the allocation
113 *
114 * Allocations are aligned to the size of the request.
115 */
116void * __meminit altmap_alloc_block_buf(unsigned long size,
117 struct vmem_altmap *altmap)
118{
119 unsigned long pfn, nr_pfns, nr_align;
120
121 if (size & ~PAGE_MASK) {
122 pr_warn_once("%s: allocations must be multiple of PAGE_SIZE (%ld)\n",
123 __func__, size);
124 return NULL;
125 }
126
127 pfn = vmem_altmap_next_pfn(altmap);
128 nr_pfns = size >> PAGE_SHIFT;
129 nr_align = 1UL << find_first_bit(&nr_pfns, BITS_PER_LONG);
130 nr_align = ALIGN(pfn, nr_align) - pfn;
131 if (nr_pfns + nr_align > vmem_altmap_nr_free(altmap))
132 return NULL;
133
134 altmap->alloc += nr_pfns;
135 altmap->align += nr_align;
136 pfn += nr_align;
137
138 pr_debug("%s: pfn: %#lx alloc: %ld align: %ld nr: %#lx\n",
139 __func__, pfn, altmap->alloc, altmap->align, nr_pfns);
140 return __va(__pfn_to_phys(pfn));
141}
142
143void __meminit vmemmap_verify(pte_t *pte, int node,
144 unsigned long start, unsigned long end)
145{
146 unsigned long pfn = pte_pfn(*pte);
147 int actual_node = early_pfn_to_nid(pfn);
148
149 if (node_distance(actual_node, node) > LOCAL_DISTANCE)
150 pr_warn("[%lx-%lx] potential offnode page_structs\n",
151 start, end - 1);
152}
153
154pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node)
155{
156 pte_t *pte = pte_offset_kernel(pmd, addr);
157 if (pte_none(*pte)) {
158 pte_t entry;
159 void *p = vmemmap_alloc_block_buf(PAGE_SIZE, node);
160 if (!p)
161 return NULL;
162 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
163 set_pte_at(&init_mm, addr, pte, entry);
164 }
165 return pte;
166}
167
168static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node)
169{
170 void *p = vmemmap_alloc_block(size, node);
171
172 if (!p)
173 return NULL;
174 memset(p, 0, size);
175
176 return p;
177}
178
179pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
180{
181 pmd_t *pmd = pmd_offset(pud, addr);
182 if (pmd_none(*pmd)) {
183 void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
184 if (!p)
185 return NULL;
186 pmd_populate_kernel(&init_mm, pmd, p);
187 }
188 return pmd;
189}
190
191pud_t * __meminit vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node)
192{
193 pud_t *pud = pud_offset(p4d, addr);
194 if (pud_none(*pud)) {
195 void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
196 if (!p)
197 return NULL;
198 pud_populate(&init_mm, pud, p);
199 }
200 return pud;
201}
202
203p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node)
204{
205 p4d_t *p4d = p4d_offset(pgd, addr);
206 if (p4d_none(*p4d)) {
207 void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
208 if (!p)
209 return NULL;
210 p4d_populate(&init_mm, p4d, p);
211 }
212 return p4d;
213}
214
215pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
216{
217 pgd_t *pgd = pgd_offset_k(addr);
218 if (pgd_none(*pgd)) {
219 void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
220 if (!p)
221 return NULL;
222 pgd_populate(&init_mm, pgd, p);
223 }
224 return pgd;
225}
226
227int __meminit vmemmap_populate_basepages(unsigned long start,
228 unsigned long end, int node)
229{
230 unsigned long addr = start;
231 pgd_t *pgd;
232 p4d_t *p4d;
233 pud_t *pud;
234 pmd_t *pmd;
235 pte_t *pte;
236
237 for (; addr < end; addr += PAGE_SIZE) {
238 pgd = vmemmap_pgd_populate(addr, node);
239 if (!pgd)
240 return -ENOMEM;
241 p4d = vmemmap_p4d_populate(pgd, addr, node);
242 if (!p4d)
243 return -ENOMEM;
244 pud = vmemmap_pud_populate(p4d, addr, node);
245 if (!pud)
246 return -ENOMEM;
247 pmd = vmemmap_pmd_populate(pud, addr, node);
248 if (!pmd)
249 return -ENOMEM;
250 pte = vmemmap_pte_populate(pmd, addr, node);
251 if (!pte)
252 return -ENOMEM;
253 vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
254 }
255
256 return 0;
257}
258
259struct page * __meminit sparse_mem_map_populate(unsigned long pnum, int nid,
260 struct vmem_altmap *altmap)
261{
262 unsigned long start;
263 unsigned long end;
264 struct page *map;
265
266 map = pfn_to_page(pnum * PAGES_PER_SECTION);
267 start = (unsigned long)map;
268 end = (unsigned long)(map + PAGES_PER_SECTION);
269
270 if (vmemmap_populate(start, end, nid, altmap))
271 return NULL;
272
273 return map;
274}
275
276void __init sparse_mem_maps_populate_node(struct page **map_map,
277 unsigned long pnum_begin,
278 unsigned long pnum_end,
279 unsigned long map_count, int nodeid)
280{
281 unsigned long pnum;
282 unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
283 void *vmemmap_buf_start;
284
285 size = ALIGN(size, PMD_SIZE);
286 vmemmap_buf_start = __earlyonly_bootmem_alloc(nodeid, size * map_count,
287 PMD_SIZE, __pa(MAX_DMA_ADDRESS));
288
289 if (vmemmap_buf_start) {
290 vmemmap_buf = vmemmap_buf_start;
291 vmemmap_buf_end = vmemmap_buf_start + size * map_count;
292 }
293
294 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
295 struct mem_section *ms;
296
297 if (!present_section_nr(pnum))
298 continue;
299
300 map_map[pnum] = sparse_mem_map_populate(pnum, nodeid, NULL);
301 if (map_map[pnum])
302 continue;
303 ms = __nr_to_section(pnum);
304 pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
305 __func__);
306 ms->section_mem_map = 0;
307 }
308
309 if (vmemmap_buf_start) {
310 /* need to free left buf */
311 memblock_free_early(__pa(vmemmap_buf),
312 vmemmap_buf_end - vmemmap_buf);
313 vmemmap_buf = NULL;
314 vmemmap_buf_end = NULL;
315 }
316}
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
38static 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
47static void *vmemmap_buf;
48static void *vmemmap_buf_end;
49
50void * __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 */
73void * __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
90void __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
101pte_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
115pmd_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
127pud_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
139pgd_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
151int __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
179struct 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
195void __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}