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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/memremap.h>
24#include <linux/highmem.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
39static void * __init_refok __earlyonly_bootmem_alloc(int node,
40 unsigned long size,
41 unsigned long align,
42 unsigned long goal)
43{
44 return memblock_virt_alloc_try_nid(size, align, goal,
45 BOOTMEM_ALLOC_ACCESSIBLE, node);
46}
47
48static void *vmemmap_buf;
49static void *vmemmap_buf_end;
50
51void * __meminit vmemmap_alloc_block(unsigned long size, int node)
52{
53 /* If the main allocator is up use that, fallback to bootmem. */
54 if (slab_is_available()) {
55 struct page *page;
56
57 if (node_state(node, N_HIGH_MEMORY))
58 page = alloc_pages_node(
59 node, GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT,
60 get_order(size));
61 else
62 page = alloc_pages(
63 GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT,
64 get_order(size));
65 if (page)
66 return page_address(page);
67 return NULL;
68 } else
69 return __earlyonly_bootmem_alloc(node, size, size,
70 __pa(MAX_DMA_ADDRESS));
71}
72
73/* need to make sure size is all the same during early stage */
74static void * __meminit alloc_block_buf(unsigned long size, int node)
75{
76 void *ptr;
77
78 if (!vmemmap_buf)
79 return vmemmap_alloc_block(size, node);
80
81 /* take the from buf */
82 ptr = (void *)ALIGN((unsigned long)vmemmap_buf, size);
83 if (ptr + size > vmemmap_buf_end)
84 return vmemmap_alloc_block(size, node);
85
86 vmemmap_buf = ptr + size;
87
88 return ptr;
89}
90
91static unsigned long __meminit vmem_altmap_next_pfn(struct vmem_altmap *altmap)
92{
93 return altmap->base_pfn + altmap->reserve + altmap->alloc
94 + altmap->align;
95}
96
97static unsigned long __meminit vmem_altmap_nr_free(struct vmem_altmap *altmap)
98{
99 unsigned long allocated = altmap->alloc + altmap->align;
100
101 if (altmap->free > allocated)
102 return altmap->free - allocated;
103 return 0;
104}
105
106/**
107 * vmem_altmap_alloc - allocate pages from the vmem_altmap reservation
108 * @altmap - reserved page pool for the allocation
109 * @nr_pfns - size (in pages) of the allocation
110 *
111 * Allocations are aligned to the size of the request
112 */
113static unsigned long __meminit vmem_altmap_alloc(struct vmem_altmap *altmap,
114 unsigned long nr_pfns)
115{
116 unsigned long pfn = vmem_altmap_next_pfn(altmap);
117 unsigned long nr_align;
118
119 nr_align = 1UL << find_first_bit(&nr_pfns, BITS_PER_LONG);
120 nr_align = ALIGN(pfn, nr_align) - pfn;
121
122 if (nr_pfns + nr_align > vmem_altmap_nr_free(altmap))
123 return ULONG_MAX;
124 altmap->alloc += nr_pfns;
125 altmap->align += nr_align;
126 return pfn + nr_align;
127}
128
129static void * __meminit altmap_alloc_block_buf(unsigned long size,
130 struct vmem_altmap *altmap)
131{
132 unsigned long pfn, nr_pfns;
133 void *ptr;
134
135 if (size & ~PAGE_MASK) {
136 pr_warn_once("%s: allocations must be multiple of PAGE_SIZE (%ld)\n",
137 __func__, size);
138 return NULL;
139 }
140
141 nr_pfns = size >> PAGE_SHIFT;
142 pfn = vmem_altmap_alloc(altmap, nr_pfns);
143 if (pfn < ULONG_MAX)
144 ptr = __va(__pfn_to_phys(pfn));
145 else
146 ptr = NULL;
147 pr_debug("%s: pfn: %#lx alloc: %ld align: %ld nr: %#lx\n",
148 __func__, pfn, altmap->alloc, altmap->align, nr_pfns);
149
150 return ptr;
151}
152
153/* need to make sure size is all the same during early stage */
154void * __meminit __vmemmap_alloc_block_buf(unsigned long size, int node,
155 struct vmem_altmap *altmap)
156{
157 if (altmap)
158 return altmap_alloc_block_buf(size, altmap);
159 return alloc_block_buf(size, node);
160}
161
162void __meminit vmemmap_verify(pte_t *pte, int node,
163 unsigned long start, unsigned long end)
164{
165 unsigned long pfn = pte_pfn(*pte);
166 int actual_node = early_pfn_to_nid(pfn);
167
168 if (node_distance(actual_node, node) > LOCAL_DISTANCE)
169 pr_warn("[%lx-%lx] potential offnode page_structs\n",
170 start, end - 1);
171}
172
173pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node)
174{
175 pte_t *pte = pte_offset_kernel(pmd, addr);
176 if (pte_none(*pte)) {
177 pte_t entry;
178 void *p = alloc_block_buf(PAGE_SIZE, node);
179 if (!p)
180 return NULL;
181 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
182 set_pte_at(&init_mm, addr, pte, entry);
183 }
184 return pte;
185}
186
187pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
188{
189 pmd_t *pmd = pmd_offset(pud, addr);
190 if (pmd_none(*pmd)) {
191 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
192 if (!p)
193 return NULL;
194 pmd_populate_kernel(&init_mm, pmd, p);
195 }
196 return pmd;
197}
198
199pud_t * __meminit vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node)
200{
201 pud_t *pud = pud_offset(pgd, addr);
202 if (pud_none(*pud)) {
203 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
204 if (!p)
205 return NULL;
206 pud_populate(&init_mm, pud, p);
207 }
208 return pud;
209}
210
211pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
212{
213 pgd_t *pgd = pgd_offset_k(addr);
214 if (pgd_none(*pgd)) {
215 void *p = vmemmap_alloc_block(PAGE_SIZE, node);
216 if (!p)
217 return NULL;
218 pgd_populate(&init_mm, pgd, p);
219 }
220 return pgd;
221}
222
223int __meminit vmemmap_populate_basepages(unsigned long start,
224 unsigned long end, int node)
225{
226 unsigned long addr = start;
227 pgd_t *pgd;
228 pud_t *pud;
229 pmd_t *pmd;
230 pte_t *pte;
231
232 for (; addr < end; addr += PAGE_SIZE) {
233 pgd = vmemmap_pgd_populate(addr, node);
234 if (!pgd)
235 return -ENOMEM;
236 pud = vmemmap_pud_populate(pgd, addr, node);
237 if (!pud)
238 return -ENOMEM;
239 pmd = vmemmap_pmd_populate(pud, addr, node);
240 if (!pmd)
241 return -ENOMEM;
242 pte = vmemmap_pte_populate(pmd, addr, node);
243 if (!pte)
244 return -ENOMEM;
245 vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
246 }
247
248 return 0;
249}
250
251struct page * __meminit sparse_mem_map_populate(unsigned long pnum, int nid)
252{
253 unsigned long start;
254 unsigned long end;
255 struct page *map;
256
257 map = pfn_to_page(pnum * PAGES_PER_SECTION);
258 start = (unsigned long)map;
259 end = (unsigned long)(map + PAGES_PER_SECTION);
260
261 if (vmemmap_populate(start, end, nid))
262 return NULL;
263
264 return map;
265}
266
267void __init sparse_mem_maps_populate_node(struct page **map_map,
268 unsigned long pnum_begin,
269 unsigned long pnum_end,
270 unsigned long map_count, int nodeid)
271{
272 unsigned long pnum;
273 unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
274 void *vmemmap_buf_start;
275
276 size = ALIGN(size, PMD_SIZE);
277 vmemmap_buf_start = __earlyonly_bootmem_alloc(nodeid, size * map_count,
278 PMD_SIZE, __pa(MAX_DMA_ADDRESS));
279
280 if (vmemmap_buf_start) {
281 vmemmap_buf = vmemmap_buf_start;
282 vmemmap_buf_end = vmemmap_buf_start + size * map_count;
283 }
284
285 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
286 struct mem_section *ms;
287
288 if (!present_section_nr(pnum))
289 continue;
290
291 map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
292 if (map_map[pnum])
293 continue;
294 ms = __nr_to_section(pnum);
295 pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
296 __func__);
297 ms->section_mem_map = 0;
298 }
299
300 if (vmemmap_buf_start) {
301 /* need to free left buf */
302 memblock_free_early(__pa(vmemmap_buf),
303 vmemmap_buf_end - vmemmap_buf);
304 vmemmap_buf = NULL;
305 vmemmap_buf_end = NULL;
306 }
307}
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/memblock.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
31#include <asm/dma.h>
32#include <asm/pgalloc.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_alloc_try_nid_raw(size, align, goal,
46 MEMBLOCK_ALLOC_ACCESSIBLE, node);
47}
48
49void * __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 gfp_t gfp_mask = GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_NOWARN;
54 int order = get_order(size);
55 static bool warned;
56 struct page *page;
57
58 page = alloc_pages_node(node, gfp_mask, order);
59 if (page)
60 return page_address(page);
61
62 if (!warned) {
63 warn_alloc(gfp_mask & ~__GFP_NOWARN, NULL,
64 "vmemmap alloc failure: order:%u", order);
65 warned = true;
66 }
67 return NULL;
68 } else
69 return __earlyonly_bootmem_alloc(node, size, size,
70 __pa(MAX_DMA_ADDRESS));
71}
72
73static void * __meminit altmap_alloc_block_buf(unsigned long size,
74 struct vmem_altmap *altmap);
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 struct vmem_altmap *altmap)
79{
80 void *ptr;
81
82 if (altmap)
83 return altmap_alloc_block_buf(size, altmap);
84
85 ptr = sparse_buffer_alloc(size);
86 if (!ptr)
87 ptr = vmemmap_alloc_block(size, node);
88 return ptr;
89}
90
91static unsigned long __meminit vmem_altmap_next_pfn(struct vmem_altmap *altmap)
92{
93 return altmap->base_pfn + altmap->reserve + altmap->alloc
94 + altmap->align;
95}
96
97static unsigned long __meminit vmem_altmap_nr_free(struct vmem_altmap *altmap)
98{
99 unsigned long allocated = altmap->alloc + altmap->align;
100
101 if (altmap->free > allocated)
102 return altmap->free - allocated;
103 return 0;
104}
105
106static void * __meminit altmap_alloc_block_buf(unsigned long size,
107 struct vmem_altmap *altmap)
108{
109 unsigned long pfn, nr_pfns, nr_align;
110
111 if (size & ~PAGE_MASK) {
112 pr_warn_once("%s: allocations must be multiple of PAGE_SIZE (%ld)\n",
113 __func__, size);
114 return NULL;
115 }
116
117 pfn = vmem_altmap_next_pfn(altmap);
118 nr_pfns = size >> PAGE_SHIFT;
119 nr_align = 1UL << find_first_bit(&nr_pfns, BITS_PER_LONG);
120 nr_align = ALIGN(pfn, nr_align) - pfn;
121 if (nr_pfns + nr_align > vmem_altmap_nr_free(altmap))
122 return NULL;
123
124 altmap->alloc += nr_pfns;
125 altmap->align += nr_align;
126 pfn += nr_align;
127
128 pr_debug("%s: pfn: %#lx alloc: %ld align: %ld nr: %#lx\n",
129 __func__, pfn, altmap->alloc, altmap->align, nr_pfns);
130 return __va(__pfn_to_phys(pfn));
131}
132
133void __meminit vmemmap_verify(pte_t *pte, int node,
134 unsigned long start, unsigned long end)
135{
136 unsigned long pfn = pte_pfn(ptep_get(pte));
137 int actual_node = early_pfn_to_nid(pfn);
138
139 if (node_distance(actual_node, node) > LOCAL_DISTANCE)
140 pr_warn_once("[%lx-%lx] potential offnode page_structs\n",
141 start, end - 1);
142}
143
144pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
145 struct vmem_altmap *altmap,
146 struct page *reuse)
147{
148 pte_t *pte = pte_offset_kernel(pmd, addr);
149 if (pte_none(ptep_get(pte))) {
150 pte_t entry;
151 void *p;
152
153 if (!reuse) {
154 p = vmemmap_alloc_block_buf(PAGE_SIZE, node, altmap);
155 if (!p)
156 return NULL;
157 } else {
158 /*
159 * When a PTE/PMD entry is freed from the init_mm
160 * there's a free_pages() call to this page allocated
161 * above. Thus this get_page() is paired with the
162 * put_page_testzero() on the freeing path.
163 * This can only called by certain ZONE_DEVICE path,
164 * and through vmemmap_populate_compound_pages() when
165 * slab is available.
166 */
167 get_page(reuse);
168 p = page_to_virt(reuse);
169 }
170 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
171 set_pte_at(&init_mm, addr, pte, entry);
172 }
173 return pte;
174}
175
176static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node)
177{
178 void *p = vmemmap_alloc_block(size, node);
179
180 if (!p)
181 return NULL;
182 memset(p, 0, size);
183
184 return p;
185}
186
187pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
188{
189 pmd_t *pmd = pmd_offset(pud, addr);
190 if (pmd_none(*pmd)) {
191 void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
192 if (!p)
193 return NULL;
194 kernel_pte_init(p);
195 pmd_populate_kernel(&init_mm, pmd, p);
196 }
197 return pmd;
198}
199
200pud_t * __meminit vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node)
201{
202 pud_t *pud = pud_offset(p4d, addr);
203 if (pud_none(*pud)) {
204 void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
205 if (!p)
206 return NULL;
207 pmd_init(p);
208 pud_populate(&init_mm, pud, p);
209 }
210 return pud;
211}
212
213p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node)
214{
215 p4d_t *p4d = p4d_offset(pgd, addr);
216 if (p4d_none(*p4d)) {
217 void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
218 if (!p)
219 return NULL;
220 pud_init(p);
221 p4d_populate(&init_mm, p4d, p);
222 }
223 return p4d;
224}
225
226pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
227{
228 pgd_t *pgd = pgd_offset_k(addr);
229 if (pgd_none(*pgd)) {
230 void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
231 if (!p)
232 return NULL;
233 pgd_populate(&init_mm, pgd, p);
234 }
235 return pgd;
236}
237
238static pte_t * __meminit vmemmap_populate_address(unsigned long addr, int node,
239 struct vmem_altmap *altmap,
240 struct page *reuse)
241{
242 pgd_t *pgd;
243 p4d_t *p4d;
244 pud_t *pud;
245 pmd_t *pmd;
246 pte_t *pte;
247
248 pgd = vmemmap_pgd_populate(addr, node);
249 if (!pgd)
250 return NULL;
251 p4d = vmemmap_p4d_populate(pgd, addr, node);
252 if (!p4d)
253 return NULL;
254 pud = vmemmap_pud_populate(p4d, addr, node);
255 if (!pud)
256 return NULL;
257 pmd = vmemmap_pmd_populate(pud, addr, node);
258 if (!pmd)
259 return NULL;
260 pte = vmemmap_pte_populate(pmd, addr, node, altmap, reuse);
261 if (!pte)
262 return NULL;
263 vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
264
265 return pte;
266}
267
268static int __meminit vmemmap_populate_range(unsigned long start,
269 unsigned long end, int node,
270 struct vmem_altmap *altmap,
271 struct page *reuse)
272{
273 unsigned long addr = start;
274 pte_t *pte;
275
276 for (; addr < end; addr += PAGE_SIZE) {
277 pte = vmemmap_populate_address(addr, node, altmap, reuse);
278 if (!pte)
279 return -ENOMEM;
280 }
281
282 return 0;
283}
284
285int __meminit vmemmap_populate_basepages(unsigned long start, unsigned long end,
286 int node, struct vmem_altmap *altmap)
287{
288 return vmemmap_populate_range(start, end, node, altmap, NULL);
289}
290
291void __weak __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
292 unsigned long addr, unsigned long next)
293{
294}
295
296int __weak __meminit vmemmap_check_pmd(pmd_t *pmd, int node,
297 unsigned long addr, unsigned long next)
298{
299 return 0;
300}
301
302int __meminit vmemmap_populate_hugepages(unsigned long start, unsigned long end,
303 int node, struct vmem_altmap *altmap)
304{
305 unsigned long addr;
306 unsigned long next;
307 pgd_t *pgd;
308 p4d_t *p4d;
309 pud_t *pud;
310 pmd_t *pmd;
311
312 for (addr = start; addr < end; addr = next) {
313 next = pmd_addr_end(addr, end);
314
315 pgd = vmemmap_pgd_populate(addr, node);
316 if (!pgd)
317 return -ENOMEM;
318
319 p4d = vmemmap_p4d_populate(pgd, addr, node);
320 if (!p4d)
321 return -ENOMEM;
322
323 pud = vmemmap_pud_populate(p4d, addr, node);
324 if (!pud)
325 return -ENOMEM;
326
327 pmd = pmd_offset(pud, addr);
328 if (pmd_none(READ_ONCE(*pmd))) {
329 void *p;
330
331 p = vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
332 if (p) {
333 vmemmap_set_pmd(pmd, p, node, addr, next);
334 continue;
335 } else if (altmap) {
336 /*
337 * No fallback: In any case we care about, the
338 * altmap should be reasonably sized and aligned
339 * such that vmemmap_alloc_block_buf() will always
340 * succeed. For consistency with the PTE case,
341 * return an error here as failure could indicate
342 * a configuration issue with the size of the altmap.
343 */
344 return -ENOMEM;
345 }
346 } else if (vmemmap_check_pmd(pmd, node, addr, next))
347 continue;
348 if (vmemmap_populate_basepages(addr, next, node, altmap))
349 return -ENOMEM;
350 }
351 return 0;
352}
353
354#ifndef vmemmap_populate_compound_pages
355/*
356 * For compound pages bigger than section size (e.g. x86 1G compound
357 * pages with 2M subsection size) fill the rest of sections as tail
358 * pages.
359 *
360 * Note that memremap_pages() resets @nr_range value and will increment
361 * it after each range successful onlining. Thus the value or @nr_range
362 * at section memmap populate corresponds to the in-progress range
363 * being onlined here.
364 */
365static bool __meminit reuse_compound_section(unsigned long start_pfn,
366 struct dev_pagemap *pgmap)
367{
368 unsigned long nr_pages = pgmap_vmemmap_nr(pgmap);
369 unsigned long offset = start_pfn -
370 PHYS_PFN(pgmap->ranges[pgmap->nr_range].start);
371
372 return !IS_ALIGNED(offset, nr_pages) && nr_pages > PAGES_PER_SUBSECTION;
373}
374
375static pte_t * __meminit compound_section_tail_page(unsigned long addr)
376{
377 pte_t *pte;
378
379 addr -= PAGE_SIZE;
380
381 /*
382 * Assuming sections are populated sequentially, the previous section's
383 * page data can be reused.
384 */
385 pte = pte_offset_kernel(pmd_off_k(addr), addr);
386 if (!pte)
387 return NULL;
388
389 return pte;
390}
391
392static int __meminit vmemmap_populate_compound_pages(unsigned long start_pfn,
393 unsigned long start,
394 unsigned long end, int node,
395 struct dev_pagemap *pgmap)
396{
397 unsigned long size, addr;
398 pte_t *pte;
399 int rc;
400
401 if (reuse_compound_section(start_pfn, pgmap)) {
402 pte = compound_section_tail_page(start);
403 if (!pte)
404 return -ENOMEM;
405
406 /*
407 * Reuse the page that was populated in the prior iteration
408 * with just tail struct pages.
409 */
410 return vmemmap_populate_range(start, end, node, NULL,
411 pte_page(ptep_get(pte)));
412 }
413
414 size = min(end - start, pgmap_vmemmap_nr(pgmap) * sizeof(struct page));
415 for (addr = start; addr < end; addr += size) {
416 unsigned long next, last = addr + size;
417
418 /* Populate the head page vmemmap page */
419 pte = vmemmap_populate_address(addr, node, NULL, NULL);
420 if (!pte)
421 return -ENOMEM;
422
423 /* Populate the tail pages vmemmap page */
424 next = addr + PAGE_SIZE;
425 pte = vmemmap_populate_address(next, node, NULL, NULL);
426 if (!pte)
427 return -ENOMEM;
428
429 /*
430 * Reuse the previous page for the rest of tail pages
431 * See layout diagram in Documentation/mm/vmemmap_dedup.rst
432 */
433 next += PAGE_SIZE;
434 rc = vmemmap_populate_range(next, last, node, NULL,
435 pte_page(ptep_get(pte)));
436 if (rc)
437 return -ENOMEM;
438 }
439
440 return 0;
441}
442
443#endif
444
445struct page * __meminit __populate_section_memmap(unsigned long pfn,
446 unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
447 struct dev_pagemap *pgmap)
448{
449 unsigned long start = (unsigned long) pfn_to_page(pfn);
450 unsigned long end = start + nr_pages * sizeof(struct page);
451 int r;
452
453 if (WARN_ON_ONCE(!IS_ALIGNED(pfn, PAGES_PER_SUBSECTION) ||
454 !IS_ALIGNED(nr_pages, PAGES_PER_SUBSECTION)))
455 return NULL;
456
457 if (vmemmap_can_optimize(altmap, pgmap))
458 r = vmemmap_populate_compound_pages(pfn, start, end, nid, pgmap);
459 else
460 r = vmemmap_populate(start, end, nid, altmap);
461
462 if (r < 0)
463 return NULL;
464
465 if (system_state == SYSTEM_BOOTING)
466 memmap_boot_pages_add(DIV_ROUND_UP(end - start, PAGE_SIZE));
467 else
468 memmap_pages_add(DIV_ROUND_UP(end - start, PAGE_SIZE));
469
470 return pfn_to_page(pfn);
471}