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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
8f6aac41 CL |
2 | /* |
3 | * Virtual Memory Map support | |
4 | * | |
cde53535 | 5 | * (C) 2007 sgi. Christoph Lameter. |
8f6aac41 CL |
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 | |
b595076a | 13 | * via TLBs. For those arches the virtual memory map is essentially |
8f6aac41 CL |
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 | * | |
29c71111 AW |
18 | * The architecture is expected to provide a vmemmap_populate() function |
19 | * to instantiate the mapping. | |
8f6aac41 CL |
20 | */ |
21 | #include <linux/mm.h> | |
22 | #include <linux/mmzone.h> | |
97ad1087 | 23 | #include <linux/memblock.h> |
4b94ffdc | 24 | #include <linux/memremap.h> |
8f6aac41 | 25 | #include <linux/highmem.h> |
5a0e3ad6 | 26 | #include <linux/slab.h> |
8f6aac41 CL |
27 | #include <linux/spinlock.h> |
28 | #include <linux/vmalloc.h> | |
8bca44bb | 29 | #include <linux/sched.h> |
8f6aac41 CL |
30 | #include <asm/dma.h> |
31 | #include <asm/pgalloc.h> | |
8f6aac41 CL |
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 | */ | |
e0dc3a53 | 38 | |
bd721ea7 | 39 | static void * __ref __earlyonly_bootmem_alloc(int node, |
e0dc3a53 KH |
40 | unsigned long size, |
41 | unsigned long align, | |
42 | unsigned long goal) | |
43 | { | |
eb31d559 | 44 | return memblock_alloc_try_nid_raw(size, align, goal, |
97ad1087 | 45 | MEMBLOCK_ALLOC_ACCESSIBLE, node); |
e0dc3a53 KH |
46 | } |
47 | ||
8f6aac41 CL |
48 | void * __meminit vmemmap_alloc_block(unsigned long size, int node) |
49 | { | |
50 | /* If the main allocator is up use that, fallback to bootmem. */ | |
51 | if (slab_is_available()) { | |
fcdaf842 MH |
52 | gfp_t gfp_mask = GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_NOWARN; |
53 | int order = get_order(size); | |
54 | static bool warned; | |
f52407ce SL |
55 | struct page *page; |
56 | ||
fcdaf842 | 57 | page = alloc_pages_node(node, gfp_mask, order); |
8f6aac41 CL |
58 | if (page) |
59 | return page_address(page); | |
fcdaf842 MH |
60 | |
61 | if (!warned) { | |
62 | warn_alloc(gfp_mask & ~__GFP_NOWARN, NULL, | |
63 | "vmemmap alloc failure: order:%u", order); | |
64 | warned = true; | |
65 | } | |
8f6aac41 CL |
66 | return NULL; |
67 | } else | |
e0dc3a53 | 68 | return __earlyonly_bootmem_alloc(node, size, size, |
8f6aac41 CL |
69 | __pa(MAX_DMA_ADDRESS)); |
70 | } | |
71 | ||
9bdac914 | 72 | /* need to make sure size is all the same during early stage */ |
a8fc357b | 73 | void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node) |
9bdac914 | 74 | { |
35fd1eb1 | 75 | void *ptr = sparse_buffer_alloc(size); |
9bdac914 | 76 | |
35fd1eb1 PT |
77 | if (!ptr) |
78 | ptr = vmemmap_alloc_block(size, node); | |
9bdac914 YL |
79 | return ptr; |
80 | } | |
81 | ||
4b94ffdc DW |
82 | static unsigned long __meminit vmem_altmap_next_pfn(struct vmem_altmap *altmap) |
83 | { | |
84 | return altmap->base_pfn + altmap->reserve + altmap->alloc | |
85 | + altmap->align; | |
86 | } | |
87 | ||
88 | static unsigned long __meminit vmem_altmap_nr_free(struct vmem_altmap *altmap) | |
89 | { | |
90 | unsigned long allocated = altmap->alloc + altmap->align; | |
91 | ||
92 | if (altmap->free > allocated) | |
93 | return altmap->free - allocated; | |
94 | return 0; | |
95 | } | |
96 | ||
97 | /** | |
eb804533 CH |
98 | * altmap_alloc_block_buf - allocate pages from the device page map |
99 | * @altmap: device page map | |
100 | * @size: size (in bytes) of the allocation | |
4b94ffdc | 101 | * |
eb804533 | 102 | * Allocations are aligned to the size of the request. |
4b94ffdc | 103 | */ |
a8fc357b | 104 | void * __meminit altmap_alloc_block_buf(unsigned long size, |
4b94ffdc DW |
105 | struct vmem_altmap *altmap) |
106 | { | |
eb804533 | 107 | unsigned long pfn, nr_pfns, nr_align; |
4b94ffdc DW |
108 | |
109 | if (size & ~PAGE_MASK) { | |
110 | pr_warn_once("%s: allocations must be multiple of PAGE_SIZE (%ld)\n", | |
111 | __func__, size); | |
112 | return NULL; | |
113 | } | |
114 | ||
eb804533 | 115 | pfn = vmem_altmap_next_pfn(altmap); |
4b94ffdc | 116 | nr_pfns = size >> PAGE_SHIFT; |
eb804533 CH |
117 | nr_align = 1UL << find_first_bit(&nr_pfns, BITS_PER_LONG); |
118 | nr_align = ALIGN(pfn, nr_align) - pfn; | |
119 | if (nr_pfns + nr_align > vmem_altmap_nr_free(altmap)) | |
120 | return NULL; | |
121 | ||
122 | altmap->alloc += nr_pfns; | |
123 | altmap->align += nr_align; | |
124 | pfn += nr_align; | |
125 | ||
4b94ffdc DW |
126 | pr_debug("%s: pfn: %#lx alloc: %ld align: %ld nr: %#lx\n", |
127 | __func__, pfn, altmap->alloc, altmap->align, nr_pfns); | |
eb804533 | 128 | return __va(__pfn_to_phys(pfn)); |
4b94ffdc DW |
129 | } |
130 | ||
8f6aac41 CL |
131 | void __meminit vmemmap_verify(pte_t *pte, int node, |
132 | unsigned long start, unsigned long end) | |
133 | { | |
134 | unsigned long pfn = pte_pfn(*pte); | |
135 | int actual_node = early_pfn_to_nid(pfn); | |
136 | ||
b41ad14c | 137 | if (node_distance(actual_node, node) > LOCAL_DISTANCE) |
1170532b JP |
138 | pr_warn("[%lx-%lx] potential offnode page_structs\n", |
139 | start, end - 1); | |
8f6aac41 CL |
140 | } |
141 | ||
29c71111 | 142 | pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node) |
8f6aac41 | 143 | { |
29c71111 AW |
144 | pte_t *pte = pte_offset_kernel(pmd, addr); |
145 | if (pte_none(*pte)) { | |
146 | pte_t entry; | |
a8fc357b | 147 | void *p = vmemmap_alloc_block_buf(PAGE_SIZE, node); |
29c71111 | 148 | if (!p) |
9dce07f1 | 149 | return NULL; |
29c71111 AW |
150 | entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL); |
151 | set_pte_at(&init_mm, addr, pte, entry); | |
152 | } | |
153 | return pte; | |
8f6aac41 CL |
154 | } |
155 | ||
f7f99100 PT |
156 | static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node) |
157 | { | |
158 | void *p = vmemmap_alloc_block(size, node); | |
159 | ||
160 | if (!p) | |
161 | return NULL; | |
162 | memset(p, 0, size); | |
163 | ||
164 | return p; | |
165 | } | |
166 | ||
29c71111 | 167 | pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node) |
8f6aac41 | 168 | { |
29c71111 AW |
169 | pmd_t *pmd = pmd_offset(pud, addr); |
170 | if (pmd_none(*pmd)) { | |
f7f99100 | 171 | void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node); |
29c71111 | 172 | if (!p) |
9dce07f1 | 173 | return NULL; |
29c71111 | 174 | pmd_populate_kernel(&init_mm, pmd, p); |
8f6aac41 | 175 | } |
29c71111 | 176 | return pmd; |
8f6aac41 | 177 | } |
8f6aac41 | 178 | |
c2febafc | 179 | pud_t * __meminit vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node) |
8f6aac41 | 180 | { |
c2febafc | 181 | pud_t *pud = pud_offset(p4d, addr); |
29c71111 | 182 | if (pud_none(*pud)) { |
f7f99100 | 183 | void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node); |
29c71111 | 184 | if (!p) |
9dce07f1 | 185 | return NULL; |
29c71111 AW |
186 | pud_populate(&init_mm, pud, p); |
187 | } | |
188 | return pud; | |
189 | } | |
8f6aac41 | 190 | |
c2febafc KS |
191 | p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node) |
192 | { | |
193 | p4d_t *p4d = p4d_offset(pgd, addr); | |
194 | if (p4d_none(*p4d)) { | |
f7f99100 | 195 | void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node); |
c2febafc KS |
196 | if (!p) |
197 | return NULL; | |
198 | p4d_populate(&init_mm, p4d, p); | |
199 | } | |
200 | return p4d; | |
201 | } | |
202 | ||
29c71111 AW |
203 | pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node) |
204 | { | |
205 | pgd_t *pgd = pgd_offset_k(addr); | |
206 | if (pgd_none(*pgd)) { | |
f7f99100 | 207 | void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node); |
29c71111 | 208 | if (!p) |
9dce07f1 | 209 | return NULL; |
29c71111 | 210 | pgd_populate(&init_mm, pgd, p); |
8f6aac41 | 211 | } |
29c71111 | 212 | return pgd; |
8f6aac41 CL |
213 | } |
214 | ||
0aad818b JW |
215 | int __meminit vmemmap_populate_basepages(unsigned long start, |
216 | unsigned long end, int node) | |
8f6aac41 | 217 | { |
0aad818b | 218 | unsigned long addr = start; |
29c71111 | 219 | pgd_t *pgd; |
c2febafc | 220 | p4d_t *p4d; |
29c71111 AW |
221 | pud_t *pud; |
222 | pmd_t *pmd; | |
223 | pte_t *pte; | |
8f6aac41 | 224 | |
29c71111 AW |
225 | for (; addr < end; addr += PAGE_SIZE) { |
226 | pgd = vmemmap_pgd_populate(addr, node); | |
227 | if (!pgd) | |
228 | return -ENOMEM; | |
c2febafc KS |
229 | p4d = vmemmap_p4d_populate(pgd, addr, node); |
230 | if (!p4d) | |
231 | return -ENOMEM; | |
232 | pud = vmemmap_pud_populate(p4d, addr, node); | |
29c71111 AW |
233 | if (!pud) |
234 | return -ENOMEM; | |
235 | pmd = vmemmap_pmd_populate(pud, addr, node); | |
236 | if (!pmd) | |
237 | return -ENOMEM; | |
238 | pte = vmemmap_pte_populate(pmd, addr, node); | |
239 | if (!pte) | |
240 | return -ENOMEM; | |
241 | vmemmap_verify(pte, node, addr, addr + PAGE_SIZE); | |
8f6aac41 | 242 | } |
29c71111 AW |
243 | |
244 | return 0; | |
8f6aac41 | 245 | } |
8f6aac41 | 246 | |
e9c0a3f0 DW |
247 | struct page * __meminit __populate_section_memmap(unsigned long pfn, |
248 | unsigned long nr_pages, int nid, struct vmem_altmap *altmap) | |
8f6aac41 | 249 | { |
0aad818b JW |
250 | unsigned long start; |
251 | unsigned long end; | |
0aad818b | 252 | |
e9c0a3f0 DW |
253 | /* |
254 | * The minimum granularity of memmap extensions is | |
255 | * PAGES_PER_SUBSECTION as allocations are tracked in the | |
256 | * 'subsection_map' bitmap of the section. | |
257 | */ | |
258 | end = ALIGN(pfn + nr_pages, PAGES_PER_SUBSECTION); | |
259 | pfn &= PAGE_SUBSECTION_MASK; | |
260 | nr_pages = end - pfn; | |
261 | ||
262 | start = (unsigned long) pfn_to_page(pfn); | |
263 | end = start + nr_pages * sizeof(struct page); | |
0aad818b | 264 | |
7b73d978 | 265 | if (vmemmap_populate(start, end, nid, altmap)) |
8f6aac41 CL |
266 | return NULL; |
267 | ||
e9c0a3f0 | 268 | return pfn_to_page(pfn); |
8f6aac41 | 269 | } |