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1/*
2 * arch/s390/mm/vmem.c
3 *
4 * Copyright IBM Corp. 2006
5 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
6 */
7
8#include <linux/bootmem.h>
9#include <linux/pfn.h>
10#include <linux/mm.h>
11#include <linux/module.h>
12#include <linux/list.h>
13#include <linux/hugetlb.h>
14#include <linux/slab.h>
15#include <asm/pgalloc.h>
16#include <asm/pgtable.h>
17#include <asm/setup.h>
18#include <asm/tlbflush.h>
19#include <asm/sections.h>
20
21static DEFINE_MUTEX(vmem_mutex);
22
23struct memory_segment {
24 struct list_head list;
25 unsigned long start;
26 unsigned long size;
27};
28
29static LIST_HEAD(mem_segs);
30
31static void __ref *vmem_alloc_pages(unsigned int order)
32{
33 if (slab_is_available())
34 return (void *)__get_free_pages(GFP_KERNEL, order);
35 return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
36}
37
38static inline pud_t *vmem_pud_alloc(void)
39{
40 pud_t *pud = NULL;
41
42#ifdef CONFIG_64BIT
43 pud = vmem_alloc_pages(2);
44 if (!pud)
45 return NULL;
46 clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
47#endif
48 return pud;
49}
50
51static inline pmd_t *vmem_pmd_alloc(void)
52{
53 pmd_t *pmd = NULL;
54
55#ifdef CONFIG_64BIT
56 pmd = vmem_alloc_pages(2);
57 if (!pmd)
58 return NULL;
59 clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
60#endif
61 return pmd;
62}
63
64static pte_t __ref *vmem_pte_alloc(unsigned long address)
65{
66 pte_t *pte;
67
68 if (slab_is_available())
69 pte = (pte_t *) page_table_alloc(&init_mm, address);
70 else
71 pte = alloc_bootmem(PTRS_PER_PTE * sizeof(pte_t));
72 if (!pte)
73 return NULL;
74 clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY,
75 PTRS_PER_PTE * sizeof(pte_t));
76 return pte;
77}
78
79/*
80 * Add a physical memory range to the 1:1 mapping.
81 */
82static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
83{
84 unsigned long address;
85 pgd_t *pg_dir;
86 pud_t *pu_dir;
87 pmd_t *pm_dir;
88 pte_t *pt_dir;
89 pte_t pte;
90 int ret = -ENOMEM;
91
92 for (address = start; address < start + size; address += PAGE_SIZE) {
93 pg_dir = pgd_offset_k(address);
94 if (pgd_none(*pg_dir)) {
95 pu_dir = vmem_pud_alloc();
96 if (!pu_dir)
97 goto out;
98 pgd_populate(&init_mm, pg_dir, pu_dir);
99 }
100
101 pu_dir = pud_offset(pg_dir, address);
102 if (pud_none(*pu_dir)) {
103 pm_dir = vmem_pmd_alloc();
104 if (!pm_dir)
105 goto out;
106 pud_populate(&init_mm, pu_dir, pm_dir);
107 }
108
109 pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
110 pm_dir = pmd_offset(pu_dir, address);
111
112#ifdef __s390x__
113 if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) &&
114 (address + HPAGE_SIZE <= start + size) &&
115 (address >= HPAGE_SIZE)) {
116 pte_val(pte) |= _SEGMENT_ENTRY_LARGE;
117 pmd_val(*pm_dir) = pte_val(pte);
118 address += HPAGE_SIZE - PAGE_SIZE;
119 continue;
120 }
121#endif
122 if (pmd_none(*pm_dir)) {
123 pt_dir = vmem_pte_alloc(address);
124 if (!pt_dir)
125 goto out;
126 pmd_populate(&init_mm, pm_dir, pt_dir);
127 }
128
129 pt_dir = pte_offset_kernel(pm_dir, address);
130 *pt_dir = pte;
131 }
132 ret = 0;
133out:
134 flush_tlb_kernel_range(start, start + size);
135 return ret;
136}
137
138/*
139 * Remove a physical memory range from the 1:1 mapping.
140 * Currently only invalidates page table entries.
141 */
142static void vmem_remove_range(unsigned long start, unsigned long size)
143{
144 unsigned long address;
145 pgd_t *pg_dir;
146 pud_t *pu_dir;
147 pmd_t *pm_dir;
148 pte_t *pt_dir;
149 pte_t pte;
150
151 pte_val(pte) = _PAGE_TYPE_EMPTY;
152 for (address = start; address < start + size; address += PAGE_SIZE) {
153 pg_dir = pgd_offset_k(address);
154 pu_dir = pud_offset(pg_dir, address);
155 if (pud_none(*pu_dir))
156 continue;
157 pm_dir = pmd_offset(pu_dir, address);
158 if (pmd_none(*pm_dir))
159 continue;
160
161 if (pmd_huge(*pm_dir)) {
162 pmd_clear(pm_dir);
163 address += HPAGE_SIZE - PAGE_SIZE;
164 continue;
165 }
166
167 pt_dir = pte_offset_kernel(pm_dir, address);
168 *pt_dir = pte;
169 }
170 flush_tlb_kernel_range(start, start + size);
171}
172
173/*
174 * Add a backed mem_map array to the virtual mem_map array.
175 */
176int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
177{
178 unsigned long address, start_addr, end_addr;
179 pgd_t *pg_dir;
180 pud_t *pu_dir;
181 pmd_t *pm_dir;
182 pte_t *pt_dir;
183 pte_t pte;
184 int ret = -ENOMEM;
185
186 start_addr = (unsigned long) start;
187 end_addr = (unsigned long) (start + nr);
188
189 for (address = start_addr; address < end_addr; address += PAGE_SIZE) {
190 pg_dir = pgd_offset_k(address);
191 if (pgd_none(*pg_dir)) {
192 pu_dir = vmem_pud_alloc();
193 if (!pu_dir)
194 goto out;
195 pgd_populate(&init_mm, pg_dir, pu_dir);
196 }
197
198 pu_dir = pud_offset(pg_dir, address);
199 if (pud_none(*pu_dir)) {
200 pm_dir = vmem_pmd_alloc();
201 if (!pm_dir)
202 goto out;
203 pud_populate(&init_mm, pu_dir, pm_dir);
204 }
205
206 pm_dir = pmd_offset(pu_dir, address);
207 if (pmd_none(*pm_dir)) {
208 pt_dir = vmem_pte_alloc(address);
209 if (!pt_dir)
210 goto out;
211 pmd_populate(&init_mm, pm_dir, pt_dir);
212 }
213
214 pt_dir = pte_offset_kernel(pm_dir, address);
215 if (pte_none(*pt_dir)) {
216 unsigned long new_page;
217
218 new_page =__pa(vmem_alloc_pages(0));
219 if (!new_page)
220 goto out;
221 pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
222 *pt_dir = pte;
223 }
224 }
225 memset(start, 0, nr * sizeof(struct page));
226 ret = 0;
227out:
228 flush_tlb_kernel_range(start_addr, end_addr);
229 return ret;
230}
231
232/*
233 * Add memory segment to the segment list if it doesn't overlap with
234 * an already present segment.
235 */
236static int insert_memory_segment(struct memory_segment *seg)
237{
238 struct memory_segment *tmp;
239
240 if (seg->start + seg->size > VMEM_MAX_PHYS ||
241 seg->start + seg->size < seg->start)
242 return -ERANGE;
243
244 list_for_each_entry(tmp, &mem_segs, list) {
245 if (seg->start >= tmp->start + tmp->size)
246 continue;
247 if (seg->start + seg->size <= tmp->start)
248 continue;
249 return -ENOSPC;
250 }
251 list_add(&seg->list, &mem_segs);
252 return 0;
253}
254
255/*
256 * Remove memory segment from the segment list.
257 */
258static void remove_memory_segment(struct memory_segment *seg)
259{
260 list_del(&seg->list);
261}
262
263static void __remove_shared_memory(struct memory_segment *seg)
264{
265 remove_memory_segment(seg);
266 vmem_remove_range(seg->start, seg->size);
267}
268
269int vmem_remove_mapping(unsigned long start, unsigned long size)
270{
271 struct memory_segment *seg;
272 int ret;
273
274 mutex_lock(&vmem_mutex);
275
276 ret = -ENOENT;
277 list_for_each_entry(seg, &mem_segs, list) {
278 if (seg->start == start && seg->size == size)
279 break;
280 }
281
282 if (seg->start != start || seg->size != size)
283 goto out;
284
285 ret = 0;
286 __remove_shared_memory(seg);
287 kfree(seg);
288out:
289 mutex_unlock(&vmem_mutex);
290 return ret;
291}
292
293int vmem_add_mapping(unsigned long start, unsigned long size)
294{
295 struct memory_segment *seg;
296 int ret;
297
298 mutex_lock(&vmem_mutex);
299 ret = -ENOMEM;
300 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
301 if (!seg)
302 goto out;
303 seg->start = start;
304 seg->size = size;
305
306 ret = insert_memory_segment(seg);
307 if (ret)
308 goto out_free;
309
310 ret = vmem_add_mem(start, size, 0);
311 if (ret)
312 goto out_remove;
313 goto out;
314
315out_remove:
316 __remove_shared_memory(seg);
317out_free:
318 kfree(seg);
319out:
320 mutex_unlock(&vmem_mutex);
321 return ret;
322}
323
324/*
325 * map whole physical memory to virtual memory (identity mapping)
326 * we reserve enough space in the vmalloc area for vmemmap to hotplug
327 * additional memory segments.
328 */
329void __init vmem_map_init(void)
330{
331 unsigned long ro_start, ro_end;
332 unsigned long start, end;
333 int i;
334
335 ro_start = ((unsigned long)&_stext) & PAGE_MASK;
336 ro_end = PFN_ALIGN((unsigned long)&_eshared);
337 for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
338 start = memory_chunk[i].addr;
339 end = memory_chunk[i].addr + memory_chunk[i].size;
340 if (start >= ro_end || end <= ro_start)
341 vmem_add_mem(start, end - start, 0);
342 else if (start >= ro_start && end <= ro_end)
343 vmem_add_mem(start, end - start, 1);
344 else if (start >= ro_start) {
345 vmem_add_mem(start, ro_end - start, 1);
346 vmem_add_mem(ro_end, end - ro_end, 0);
347 } else if (end < ro_end) {
348 vmem_add_mem(start, ro_start - start, 0);
349 vmem_add_mem(ro_start, end - ro_start, 1);
350 } else {
351 vmem_add_mem(start, ro_start - start, 0);
352 vmem_add_mem(ro_start, ro_end - ro_start, 1);
353 vmem_add_mem(ro_end, end - ro_end, 0);
354 }
355 }
356}
357
358/*
359 * Convert memory chunk array to a memory segment list so there is a single
360 * list that contains both r/w memory and shared memory segments.
361 */
362static int __init vmem_convert_memory_chunk(void)
363{
364 struct memory_segment *seg;
365 int i;
366
367 mutex_lock(&vmem_mutex);
368 for (i = 0; i < MEMORY_CHUNKS; i++) {
369 if (!memory_chunk[i].size)
370 continue;
371 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
372 if (!seg)
373 panic("Out of memory...\n");
374 seg->start = memory_chunk[i].addr;
375 seg->size = memory_chunk[i].size;
376 insert_memory_segment(seg);
377 }
378 mutex_unlock(&vmem_mutex);
379 return 0;
380}
381
382core_initcall(vmem_convert_memory_chunk);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2006
4 */
5
6#include <linux/memory_hotplug.h>
7#include <linux/memblock.h>
8#include <linux/pfn.h>
9#include <linux/mm.h>
10#include <linux/init.h>
11#include <linux/list.h>
12#include <linux/hugetlb.h>
13#include <linux/slab.h>
14#include <linux/sort.h>
15#include <asm/page-states.h>
16#include <asm/cacheflush.h>
17#include <asm/nospec-branch.h>
18#include <asm/ctlreg.h>
19#include <asm/pgalloc.h>
20#include <asm/setup.h>
21#include <asm/tlbflush.h>
22#include <asm/sections.h>
23#include <asm/set_memory.h>
24
25static DEFINE_MUTEX(vmem_mutex);
26
27static void __ref *vmem_alloc_pages(unsigned int order)
28{
29 unsigned long size = PAGE_SIZE << order;
30
31 if (slab_is_available())
32 return (void *)__get_free_pages(GFP_KERNEL, order);
33 return memblock_alloc(size, size);
34}
35
36static void vmem_free_pages(unsigned long addr, int order)
37{
38 /* We don't expect boot memory to be removed ever. */
39 if (!slab_is_available() ||
40 WARN_ON_ONCE(PageReserved(virt_to_page((void *)addr))))
41 return;
42 free_pages(addr, order);
43}
44
45void *vmem_crst_alloc(unsigned long val)
46{
47 unsigned long *table;
48
49 table = vmem_alloc_pages(CRST_ALLOC_ORDER);
50 if (!table)
51 return NULL;
52 crst_table_init(table, val);
53 __arch_set_page_dat(table, 1UL << CRST_ALLOC_ORDER);
54 return table;
55}
56
57pte_t __ref *vmem_pte_alloc(void)
58{
59 unsigned long size = PTRS_PER_PTE * sizeof(pte_t);
60 pte_t *pte;
61
62 if (slab_is_available())
63 pte = (pte_t *) page_table_alloc(&init_mm);
64 else
65 pte = (pte_t *) memblock_alloc(size, size);
66 if (!pte)
67 return NULL;
68 memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
69 __arch_set_page_dat(pte, 1);
70 return pte;
71}
72
73static void vmem_pte_free(unsigned long *table)
74{
75 /* We don't expect boot memory to be removed ever. */
76 if (!slab_is_available() ||
77 WARN_ON_ONCE(PageReserved(virt_to_page(table))))
78 return;
79 page_table_free(&init_mm, table);
80}
81
82#define PAGE_UNUSED 0xFD
83
84/*
85 * The unused vmemmap range, which was not yet memset(PAGE_UNUSED) ranges
86 * from unused_sub_pmd_start to next PMD_SIZE boundary.
87 */
88static unsigned long unused_sub_pmd_start;
89
90static void vmemmap_flush_unused_sub_pmd(void)
91{
92 if (!unused_sub_pmd_start)
93 return;
94 memset((void *)unused_sub_pmd_start, PAGE_UNUSED,
95 ALIGN(unused_sub_pmd_start, PMD_SIZE) - unused_sub_pmd_start);
96 unused_sub_pmd_start = 0;
97}
98
99static void vmemmap_mark_sub_pmd_used(unsigned long start, unsigned long end)
100{
101 /*
102 * As we expect to add in the same granularity as we remove, it's
103 * sufficient to mark only some piece used to block the memmap page from
104 * getting removed (just in case the memmap never gets initialized,
105 * e.g., because the memory block never gets onlined).
106 */
107 memset((void *)start, 0, sizeof(struct page));
108}
109
110static void vmemmap_use_sub_pmd(unsigned long start, unsigned long end)
111{
112 /*
113 * We only optimize if the new used range directly follows the
114 * previously unused range (esp., when populating consecutive sections).
115 */
116 if (unused_sub_pmd_start == start) {
117 unused_sub_pmd_start = end;
118 if (likely(IS_ALIGNED(unused_sub_pmd_start, PMD_SIZE)))
119 unused_sub_pmd_start = 0;
120 return;
121 }
122 vmemmap_flush_unused_sub_pmd();
123 vmemmap_mark_sub_pmd_used(start, end);
124}
125
126static void vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
127{
128 unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
129
130 vmemmap_flush_unused_sub_pmd();
131
132 /* Could be our memmap page is filled with PAGE_UNUSED already ... */
133 vmemmap_mark_sub_pmd_used(start, end);
134
135 /* Mark the unused parts of the new memmap page PAGE_UNUSED. */
136 if (!IS_ALIGNED(start, PMD_SIZE))
137 memset((void *)page, PAGE_UNUSED, start - page);
138 /*
139 * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of
140 * consecutive sections. Remember for the last added PMD the last
141 * unused range in the populated PMD.
142 */
143 if (!IS_ALIGNED(end, PMD_SIZE))
144 unused_sub_pmd_start = end;
145}
146
147/* Returns true if the PMD is completely unused and can be freed. */
148static bool vmemmap_unuse_sub_pmd(unsigned long start, unsigned long end)
149{
150 unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
151
152 vmemmap_flush_unused_sub_pmd();
153 memset((void *)start, PAGE_UNUSED, end - start);
154 return !memchr_inv((void *)page, PAGE_UNUSED, PMD_SIZE);
155}
156
157/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
158static int __ref modify_pte_table(pmd_t *pmd, unsigned long addr,
159 unsigned long end, bool add, bool direct)
160{
161 unsigned long prot, pages = 0;
162 int ret = -ENOMEM;
163 pte_t *pte;
164
165 prot = pgprot_val(PAGE_KERNEL);
166 if (!MACHINE_HAS_NX)
167 prot &= ~_PAGE_NOEXEC;
168
169 pte = pte_offset_kernel(pmd, addr);
170 for (; addr < end; addr += PAGE_SIZE, pte++) {
171 if (!add) {
172 if (pte_none(*pte))
173 continue;
174 if (!direct)
175 vmem_free_pages((unsigned long) pfn_to_virt(pte_pfn(*pte)), 0);
176 pte_clear(&init_mm, addr, pte);
177 } else if (pte_none(*pte)) {
178 if (!direct) {
179 void *new_page = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
180
181 if (!new_page)
182 goto out;
183 set_pte(pte, __pte(__pa(new_page) | prot));
184 } else {
185 set_pte(pte, __pte(__pa(addr) | prot));
186 }
187 } else {
188 continue;
189 }
190 pages++;
191 }
192 ret = 0;
193out:
194 if (direct)
195 update_page_count(PG_DIRECT_MAP_4K, add ? pages : -pages);
196 return ret;
197}
198
199static void try_free_pte_table(pmd_t *pmd, unsigned long start)
200{
201 pte_t *pte;
202 int i;
203
204 /* We can safely assume this is fully in 1:1 mapping & vmemmap area */
205 pte = pte_offset_kernel(pmd, start);
206 for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
207 if (!pte_none(*pte))
208 return;
209 }
210 vmem_pte_free((unsigned long *) pmd_deref(*pmd));
211 pmd_clear(pmd);
212}
213
214/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
215static int __ref modify_pmd_table(pud_t *pud, unsigned long addr,
216 unsigned long end, bool add, bool direct)
217{
218 unsigned long next, prot, pages = 0;
219 int ret = -ENOMEM;
220 pmd_t *pmd;
221 pte_t *pte;
222
223 prot = pgprot_val(SEGMENT_KERNEL);
224 if (!MACHINE_HAS_NX)
225 prot &= ~_SEGMENT_ENTRY_NOEXEC;
226
227 pmd = pmd_offset(pud, addr);
228 for (; addr < end; addr = next, pmd++) {
229 next = pmd_addr_end(addr, end);
230 if (!add) {
231 if (pmd_none(*pmd))
232 continue;
233 if (pmd_large(*pmd)) {
234 if (IS_ALIGNED(addr, PMD_SIZE) &&
235 IS_ALIGNED(next, PMD_SIZE)) {
236 if (!direct)
237 vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE));
238 pmd_clear(pmd);
239 pages++;
240 } else if (!direct && vmemmap_unuse_sub_pmd(addr, next)) {
241 vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE));
242 pmd_clear(pmd);
243 }
244 continue;
245 }
246 } else if (pmd_none(*pmd)) {
247 if (IS_ALIGNED(addr, PMD_SIZE) &&
248 IS_ALIGNED(next, PMD_SIZE) &&
249 MACHINE_HAS_EDAT1 && direct &&
250 !debug_pagealloc_enabled()) {
251 set_pmd(pmd, __pmd(__pa(addr) | prot));
252 pages++;
253 continue;
254 } else if (!direct && MACHINE_HAS_EDAT1) {
255 void *new_page;
256
257 /*
258 * Use 1MB frames for vmemmap if available. We
259 * always use large frames even if they are only
260 * partially used. Otherwise we would have also
261 * page tables since vmemmap_populate gets
262 * called for each section separately.
263 */
264 new_page = vmemmap_alloc_block(PMD_SIZE, NUMA_NO_NODE);
265 if (new_page) {
266 set_pmd(pmd, __pmd(__pa(new_page) | prot));
267 if (!IS_ALIGNED(addr, PMD_SIZE) ||
268 !IS_ALIGNED(next, PMD_SIZE)) {
269 vmemmap_use_new_sub_pmd(addr, next);
270 }
271 continue;
272 }
273 }
274 pte = vmem_pte_alloc();
275 if (!pte)
276 goto out;
277 pmd_populate(&init_mm, pmd, pte);
278 } else if (pmd_large(*pmd)) {
279 if (!direct)
280 vmemmap_use_sub_pmd(addr, next);
281 continue;
282 }
283 ret = modify_pte_table(pmd, addr, next, add, direct);
284 if (ret)
285 goto out;
286 if (!add)
287 try_free_pte_table(pmd, addr & PMD_MASK);
288 }
289 ret = 0;
290out:
291 if (direct)
292 update_page_count(PG_DIRECT_MAP_1M, add ? pages : -pages);
293 return ret;
294}
295
296static void try_free_pmd_table(pud_t *pud, unsigned long start)
297{
298 pmd_t *pmd;
299 int i;
300
301 pmd = pmd_offset(pud, start);
302 for (i = 0; i < PTRS_PER_PMD; i++, pmd++)
303 if (!pmd_none(*pmd))
304 return;
305 vmem_free_pages(pud_deref(*pud), CRST_ALLOC_ORDER);
306 pud_clear(pud);
307}
308
309static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end,
310 bool add, bool direct)
311{
312 unsigned long next, prot, pages = 0;
313 int ret = -ENOMEM;
314 pud_t *pud;
315 pmd_t *pmd;
316
317 prot = pgprot_val(REGION3_KERNEL);
318 if (!MACHINE_HAS_NX)
319 prot &= ~_REGION_ENTRY_NOEXEC;
320 pud = pud_offset(p4d, addr);
321 for (; addr < end; addr = next, pud++) {
322 next = pud_addr_end(addr, end);
323 if (!add) {
324 if (pud_none(*pud))
325 continue;
326 if (pud_large(*pud)) {
327 if (IS_ALIGNED(addr, PUD_SIZE) &&
328 IS_ALIGNED(next, PUD_SIZE)) {
329 pud_clear(pud);
330 pages++;
331 }
332 continue;
333 }
334 } else if (pud_none(*pud)) {
335 if (IS_ALIGNED(addr, PUD_SIZE) &&
336 IS_ALIGNED(next, PUD_SIZE) &&
337 MACHINE_HAS_EDAT2 && direct &&
338 !debug_pagealloc_enabled()) {
339 set_pud(pud, __pud(__pa(addr) | prot));
340 pages++;
341 continue;
342 }
343 pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
344 if (!pmd)
345 goto out;
346 pud_populate(&init_mm, pud, pmd);
347 } else if (pud_large(*pud)) {
348 continue;
349 }
350 ret = modify_pmd_table(pud, addr, next, add, direct);
351 if (ret)
352 goto out;
353 if (!add)
354 try_free_pmd_table(pud, addr & PUD_MASK);
355 }
356 ret = 0;
357out:
358 if (direct)
359 update_page_count(PG_DIRECT_MAP_2G, add ? pages : -pages);
360 return ret;
361}
362
363static void try_free_pud_table(p4d_t *p4d, unsigned long start)
364{
365 pud_t *pud;
366 int i;
367
368 pud = pud_offset(p4d, start);
369 for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
370 if (!pud_none(*pud))
371 return;
372 }
373 vmem_free_pages(p4d_deref(*p4d), CRST_ALLOC_ORDER);
374 p4d_clear(p4d);
375}
376
377static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end,
378 bool add, bool direct)
379{
380 unsigned long next;
381 int ret = -ENOMEM;
382 p4d_t *p4d;
383 pud_t *pud;
384
385 p4d = p4d_offset(pgd, addr);
386 for (; addr < end; addr = next, p4d++) {
387 next = p4d_addr_end(addr, end);
388 if (!add) {
389 if (p4d_none(*p4d))
390 continue;
391 } else if (p4d_none(*p4d)) {
392 pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
393 if (!pud)
394 goto out;
395 p4d_populate(&init_mm, p4d, pud);
396 }
397 ret = modify_pud_table(p4d, addr, next, add, direct);
398 if (ret)
399 goto out;
400 if (!add)
401 try_free_pud_table(p4d, addr & P4D_MASK);
402 }
403 ret = 0;
404out:
405 return ret;
406}
407
408static void try_free_p4d_table(pgd_t *pgd, unsigned long start)
409{
410 p4d_t *p4d;
411 int i;
412
413 p4d = p4d_offset(pgd, start);
414 for (i = 0; i < PTRS_PER_P4D; i++, p4d++) {
415 if (!p4d_none(*p4d))
416 return;
417 }
418 vmem_free_pages(pgd_deref(*pgd), CRST_ALLOC_ORDER);
419 pgd_clear(pgd);
420}
421
422static int modify_pagetable(unsigned long start, unsigned long end, bool add,
423 bool direct)
424{
425 unsigned long addr, next;
426 int ret = -ENOMEM;
427 pgd_t *pgd;
428 p4d_t *p4d;
429
430 if (WARN_ON_ONCE(!PAGE_ALIGNED(start | end)))
431 return -EINVAL;
432 /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */
433 if (WARN_ON_ONCE(end > VMALLOC_START))
434 return -EINVAL;
435 for (addr = start; addr < end; addr = next) {
436 next = pgd_addr_end(addr, end);
437 pgd = pgd_offset_k(addr);
438
439 if (!add) {
440 if (pgd_none(*pgd))
441 continue;
442 } else if (pgd_none(*pgd)) {
443 p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
444 if (!p4d)
445 goto out;
446 pgd_populate(&init_mm, pgd, p4d);
447 }
448 ret = modify_p4d_table(pgd, addr, next, add, direct);
449 if (ret)
450 goto out;
451 if (!add)
452 try_free_p4d_table(pgd, addr & PGDIR_MASK);
453 }
454 ret = 0;
455out:
456 if (!add)
457 flush_tlb_kernel_range(start, end);
458 return ret;
459}
460
461static int add_pagetable(unsigned long start, unsigned long end, bool direct)
462{
463 return modify_pagetable(start, end, true, direct);
464}
465
466static int remove_pagetable(unsigned long start, unsigned long end, bool direct)
467{
468 return modify_pagetable(start, end, false, direct);
469}
470
471/*
472 * Add a physical memory range to the 1:1 mapping.
473 */
474static int vmem_add_range(unsigned long start, unsigned long size)
475{
476 start = (unsigned long)__va(start);
477 return add_pagetable(start, start + size, true);
478}
479
480/*
481 * Remove a physical memory range from the 1:1 mapping.
482 */
483static void vmem_remove_range(unsigned long start, unsigned long size)
484{
485 start = (unsigned long)__va(start);
486 remove_pagetable(start, start + size, true);
487}
488
489/*
490 * Add a backed mem_map array to the virtual mem_map array.
491 */
492int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
493 struct vmem_altmap *altmap)
494{
495 int ret;
496
497 mutex_lock(&vmem_mutex);
498 /* We don't care about the node, just use NUMA_NO_NODE on allocations */
499 ret = add_pagetable(start, end, false);
500 if (ret)
501 remove_pagetable(start, end, false);
502 mutex_unlock(&vmem_mutex);
503 return ret;
504}
505
506#ifdef CONFIG_MEMORY_HOTPLUG
507
508void vmemmap_free(unsigned long start, unsigned long end,
509 struct vmem_altmap *altmap)
510{
511 mutex_lock(&vmem_mutex);
512 remove_pagetable(start, end, false);
513 mutex_unlock(&vmem_mutex);
514}
515
516#endif
517
518void vmem_remove_mapping(unsigned long start, unsigned long size)
519{
520 mutex_lock(&vmem_mutex);
521 vmem_remove_range(start, size);
522 mutex_unlock(&vmem_mutex);
523}
524
525struct range arch_get_mappable_range(void)
526{
527 struct range mhp_range;
528
529 mhp_range.start = 0;
530 mhp_range.end = max_mappable - 1;
531 return mhp_range;
532}
533
534int vmem_add_mapping(unsigned long start, unsigned long size)
535{
536 struct range range = arch_get_mappable_range();
537 int ret;
538
539 if (start < range.start ||
540 start + size > range.end + 1 ||
541 start + size < start)
542 return -ERANGE;
543
544 mutex_lock(&vmem_mutex);
545 ret = vmem_add_range(start, size);
546 if (ret)
547 vmem_remove_range(start, size);
548 mutex_unlock(&vmem_mutex);
549 return ret;
550}
551
552/*
553 * Allocate new or return existing page-table entry, but do not map it
554 * to any physical address. If missing, allocate segment- and region-
555 * table entries along. Meeting a large segment- or region-table entry
556 * while traversing is an error, since the function is expected to be
557 * called against virtual regions reserved for 4KB mappings only.
558 */
559pte_t *vmem_get_alloc_pte(unsigned long addr, bool alloc)
560{
561 pte_t *ptep = NULL;
562 pgd_t *pgd;
563 p4d_t *p4d;
564 pud_t *pud;
565 pmd_t *pmd;
566 pte_t *pte;
567
568 pgd = pgd_offset_k(addr);
569 if (pgd_none(*pgd)) {
570 if (!alloc)
571 goto out;
572 p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
573 if (!p4d)
574 goto out;
575 pgd_populate(&init_mm, pgd, p4d);
576 }
577 p4d = p4d_offset(pgd, addr);
578 if (p4d_none(*p4d)) {
579 if (!alloc)
580 goto out;
581 pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
582 if (!pud)
583 goto out;
584 p4d_populate(&init_mm, p4d, pud);
585 }
586 pud = pud_offset(p4d, addr);
587 if (pud_none(*pud)) {
588 if (!alloc)
589 goto out;
590 pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
591 if (!pmd)
592 goto out;
593 pud_populate(&init_mm, pud, pmd);
594 } else if (WARN_ON_ONCE(pud_large(*pud))) {
595 goto out;
596 }
597 pmd = pmd_offset(pud, addr);
598 if (pmd_none(*pmd)) {
599 if (!alloc)
600 goto out;
601 pte = vmem_pte_alloc();
602 if (!pte)
603 goto out;
604 pmd_populate(&init_mm, pmd, pte);
605 } else if (WARN_ON_ONCE(pmd_large(*pmd))) {
606 goto out;
607 }
608 ptep = pte_offset_kernel(pmd, addr);
609out:
610 return ptep;
611}
612
613int __vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot, bool alloc)
614{
615 pte_t *ptep, pte;
616
617 if (!IS_ALIGNED(addr, PAGE_SIZE))
618 return -EINVAL;
619 ptep = vmem_get_alloc_pte(addr, alloc);
620 if (!ptep)
621 return -ENOMEM;
622 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
623 pte = mk_pte_phys(phys, prot);
624 set_pte(ptep, pte);
625 return 0;
626}
627
628int vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot)
629{
630 int rc;
631
632 mutex_lock(&vmem_mutex);
633 rc = __vmem_map_4k_page(addr, phys, prot, true);
634 mutex_unlock(&vmem_mutex);
635 return rc;
636}
637
638void vmem_unmap_4k_page(unsigned long addr)
639{
640 pte_t *ptep;
641
642 mutex_lock(&vmem_mutex);
643 ptep = virt_to_kpte(addr);
644 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
645 pte_clear(&init_mm, addr, ptep);
646 mutex_unlock(&vmem_mutex);
647}
648
649void __init vmem_map_init(void)
650{
651 __set_memory_rox(_stext, _etext);
652 __set_memory_ro(_etext, __end_rodata);
653 __set_memory_rox(_sinittext, _einittext);
654 __set_memory_rox(__stext_amode31, __etext_amode31);
655 /*
656 * If the BEAR-enhancement facility is not installed the first
657 * prefix page is used to return to the previous context with
658 * an LPSWE instruction and therefore must be executable.
659 */
660 if (!static_key_enabled(&cpu_has_bear))
661 set_memory_x(0, 1);
662 if (debug_pagealloc_enabled()) {
663 /*
664 * Use RELOC_HIDE() as long as __va(0) translates to NULL,
665 * since performing pointer arithmetic on a NULL pointer
666 * has undefined behavior and generates compiler warnings.
667 */
668 __set_memory_4k(__va(0), RELOC_HIDE(__va(0), ident_map_size));
669 }
670 if (MACHINE_HAS_NX)
671 system_ctl_set_bit(0, CR0_INSTRUCTION_EXEC_PROTECTION_BIT);
672 pr_info("Write protected kernel read-only data: %luk\n",
673 (unsigned long)(__end_rodata - _stext) >> 10);
674}