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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2011
4 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
5 */
6#include <linux/hugetlb.h>
7#include <linux/proc_fs.h>
8#include <linux/vmalloc.h>
9#include <linux/mm.h>
10#include <asm/cacheflush.h>
11#include <asm/facility.h>
12#include <asm/pgalloc.h>
13#include <asm/kfence.h>
14#include <asm/page.h>
15#include <asm/asm.h>
16#include <asm/set_memory.h>
17
18static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
19{
20 asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],1,0"
21 : [addr] "+a" (addr) : [skey] "d" (skey));
22 return addr;
23}
24
25void __storage_key_init_range(unsigned long start, unsigned long end)
26{
27 unsigned long boundary, size;
28
29 while (start < end) {
30 if (MACHINE_HAS_EDAT1) {
31 /* set storage keys for a 1MB frame */
32 size = 1UL << 20;
33 boundary = (start + size) & ~(size - 1);
34 if (boundary <= end) {
35 do {
36 start = sske_frame(start, PAGE_DEFAULT_KEY);
37 } while (start < boundary);
38 continue;
39 }
40 }
41 page_set_storage_key(start, PAGE_DEFAULT_KEY, 1);
42 start += PAGE_SIZE;
43 }
44}
45
46#ifdef CONFIG_PROC_FS
47atomic_long_t __bootdata_preserved(direct_pages_count[PG_DIRECT_MAP_MAX]);
48
49void arch_report_meminfo(struct seq_file *m)
50{
51 seq_printf(m, "DirectMap4k: %8lu kB\n",
52 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_4K]) << 2);
53 seq_printf(m, "DirectMap1M: %8lu kB\n",
54 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_1M]) << 10);
55 seq_printf(m, "DirectMap2G: %8lu kB\n",
56 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_2G]) << 21);
57}
58#endif /* CONFIG_PROC_FS */
59
60static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr,
61 unsigned long dtt)
62{
63 unsigned long *table, mask;
64
65 mask = 0;
66 if (MACHINE_HAS_EDAT2) {
67 switch (dtt) {
68 case CRDTE_DTT_REGION3:
69 mask = ~(PTRS_PER_PUD * sizeof(pud_t) - 1);
70 break;
71 case CRDTE_DTT_SEGMENT:
72 mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
73 break;
74 case CRDTE_DTT_PAGE:
75 mask = ~(PTRS_PER_PTE * sizeof(pte_t) - 1);
76 break;
77 }
78 table = (unsigned long *)((unsigned long)old & mask);
79 crdte(*old, new, table, dtt, addr, get_lowcore()->kernel_asce.val);
80 } else if (MACHINE_HAS_IDTE) {
81 cspg(old, *old, new);
82 } else {
83 csp((unsigned int *)old + 1, *old, new);
84 }
85}
86
87static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end,
88 unsigned long flags)
89{
90 pte_t *ptep, new;
91
92 if (flags == SET_MEMORY_4K)
93 return 0;
94 ptep = pte_offset_kernel(pmdp, addr);
95 do {
96 new = *ptep;
97 if (pte_none(new))
98 return -EINVAL;
99 if (flags & SET_MEMORY_RO)
100 new = pte_wrprotect(new);
101 else if (flags & SET_MEMORY_RW)
102 new = pte_mkwrite_novma(pte_mkdirty(new));
103 if (flags & SET_MEMORY_NX)
104 new = set_pte_bit(new, __pgprot(_PAGE_NOEXEC));
105 else if (flags & SET_MEMORY_X)
106 new = clear_pte_bit(new, __pgprot(_PAGE_NOEXEC));
107 if (flags & SET_MEMORY_INV) {
108 new = set_pte_bit(new, __pgprot(_PAGE_INVALID));
109 } else if (flags & SET_MEMORY_DEF) {
110 new = __pte(pte_val(new) & PAGE_MASK);
111 new = set_pte_bit(new, PAGE_KERNEL);
112 if (!MACHINE_HAS_NX)
113 new = clear_pte_bit(new, __pgprot(_PAGE_NOEXEC));
114 }
115 pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE);
116 ptep++;
117 addr += PAGE_SIZE;
118 cond_resched();
119 } while (addr < end);
120 return 0;
121}
122
123static int split_pmd_page(pmd_t *pmdp, unsigned long addr)
124{
125 unsigned long pte_addr, prot;
126 pte_t *pt_dir, *ptep;
127 pmd_t new;
128 int i, ro, nx;
129
130 pt_dir = vmem_pte_alloc();
131 if (!pt_dir)
132 return -ENOMEM;
133 pte_addr = pmd_pfn(*pmdp) << PAGE_SHIFT;
134 ro = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT);
135 nx = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_NOEXEC);
136 prot = pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL);
137 if (!nx)
138 prot &= ~_PAGE_NOEXEC;
139 ptep = pt_dir;
140 for (i = 0; i < PTRS_PER_PTE; i++) {
141 set_pte(ptep, __pte(pte_addr | prot));
142 pte_addr += PAGE_SIZE;
143 ptep++;
144 }
145 new = __pmd(__pa(pt_dir) | _SEGMENT_ENTRY);
146 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);
147 update_page_count(PG_DIRECT_MAP_4K, PTRS_PER_PTE);
148 update_page_count(PG_DIRECT_MAP_1M, -1);
149 return 0;
150}
151
152static void modify_pmd_page(pmd_t *pmdp, unsigned long addr,
153 unsigned long flags)
154{
155 pmd_t new = *pmdp;
156
157 if (flags & SET_MEMORY_RO)
158 new = pmd_wrprotect(new);
159 else if (flags & SET_MEMORY_RW)
160 new = pmd_mkwrite_novma(pmd_mkdirty(new));
161 if (flags & SET_MEMORY_NX)
162 new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC));
163 else if (flags & SET_MEMORY_X)
164 new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC));
165 if (flags & SET_MEMORY_INV) {
166 new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_INVALID));
167 } else if (flags & SET_MEMORY_DEF) {
168 new = __pmd(pmd_val(new) & PMD_MASK);
169 new = set_pmd_bit(new, SEGMENT_KERNEL);
170 if (!MACHINE_HAS_NX)
171 new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC));
172 }
173 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);
174}
175
176static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end,
177 unsigned long flags)
178{
179 unsigned long next;
180 int need_split;
181 pmd_t *pmdp;
182 int rc = 0;
183
184 pmdp = pmd_offset(pudp, addr);
185 do {
186 if (pmd_none(*pmdp))
187 return -EINVAL;
188 next = pmd_addr_end(addr, end);
189 if (pmd_leaf(*pmdp)) {
190 need_split = !!(flags & SET_MEMORY_4K);
191 need_split |= !!(addr & ~PMD_MASK);
192 need_split |= !!(addr + PMD_SIZE > next);
193 if (need_split) {
194 rc = split_pmd_page(pmdp, addr);
195 if (rc)
196 return rc;
197 continue;
198 }
199 modify_pmd_page(pmdp, addr, flags);
200 } else {
201 rc = walk_pte_level(pmdp, addr, next, flags);
202 if (rc)
203 return rc;
204 }
205 pmdp++;
206 addr = next;
207 cond_resched();
208 } while (addr < end);
209 return rc;
210}
211
212static int split_pud_page(pud_t *pudp, unsigned long addr)
213{
214 unsigned long pmd_addr, prot;
215 pmd_t *pm_dir, *pmdp;
216 pud_t new;
217 int i, ro, nx;
218
219 pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
220 if (!pm_dir)
221 return -ENOMEM;
222 pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT;
223 ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT);
224 nx = !!(pud_val(*pudp) & _REGION_ENTRY_NOEXEC);
225 prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL);
226 if (!nx)
227 prot &= ~_SEGMENT_ENTRY_NOEXEC;
228 pmdp = pm_dir;
229 for (i = 0; i < PTRS_PER_PMD; i++) {
230 set_pmd(pmdp, __pmd(pmd_addr | prot));
231 pmd_addr += PMD_SIZE;
232 pmdp++;
233 }
234 new = __pud(__pa(pm_dir) | _REGION3_ENTRY);
235 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
236 update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD);
237 update_page_count(PG_DIRECT_MAP_2G, -1);
238 return 0;
239}
240
241static void modify_pud_page(pud_t *pudp, unsigned long addr,
242 unsigned long flags)
243{
244 pud_t new = *pudp;
245
246 if (flags & SET_MEMORY_RO)
247 new = pud_wrprotect(new);
248 else if (flags & SET_MEMORY_RW)
249 new = pud_mkwrite(pud_mkdirty(new));
250 if (flags & SET_MEMORY_NX)
251 new = set_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC));
252 else if (flags & SET_MEMORY_X)
253 new = clear_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC));
254 if (flags & SET_MEMORY_INV) {
255 new = set_pud_bit(new, __pgprot(_REGION_ENTRY_INVALID));
256 } else if (flags & SET_MEMORY_DEF) {
257 new = __pud(pud_val(new) & PUD_MASK);
258 new = set_pud_bit(new, REGION3_KERNEL);
259 if (!MACHINE_HAS_NX)
260 new = clear_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC));
261 }
262 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
263}
264
265static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end,
266 unsigned long flags)
267{
268 unsigned long next;
269 int need_split;
270 pud_t *pudp;
271 int rc = 0;
272
273 pudp = pud_offset(p4d, addr);
274 do {
275 if (pud_none(*pudp))
276 return -EINVAL;
277 next = pud_addr_end(addr, end);
278 if (pud_leaf(*pudp)) {
279 need_split = !!(flags & SET_MEMORY_4K);
280 need_split |= !!(addr & ~PUD_MASK);
281 need_split |= !!(addr + PUD_SIZE > next);
282 if (need_split) {
283 rc = split_pud_page(pudp, addr);
284 if (rc)
285 break;
286 continue;
287 }
288 modify_pud_page(pudp, addr, flags);
289 } else {
290 rc = walk_pmd_level(pudp, addr, next, flags);
291 }
292 pudp++;
293 addr = next;
294 cond_resched();
295 } while (addr < end && !rc);
296 return rc;
297}
298
299static int walk_p4d_level(pgd_t *pgd, unsigned long addr, unsigned long end,
300 unsigned long flags)
301{
302 unsigned long next;
303 p4d_t *p4dp;
304 int rc = 0;
305
306 p4dp = p4d_offset(pgd, addr);
307 do {
308 if (p4d_none(*p4dp))
309 return -EINVAL;
310 next = p4d_addr_end(addr, end);
311 rc = walk_pud_level(p4dp, addr, next, flags);
312 p4dp++;
313 addr = next;
314 cond_resched();
315 } while (addr < end && !rc);
316 return rc;
317}
318
319DEFINE_MUTEX(cpa_mutex);
320
321static int change_page_attr(unsigned long addr, unsigned long end,
322 unsigned long flags)
323{
324 unsigned long next;
325 int rc = -EINVAL;
326 pgd_t *pgdp;
327
328 pgdp = pgd_offset_k(addr);
329 do {
330 if (pgd_none(*pgdp))
331 break;
332 next = pgd_addr_end(addr, end);
333 rc = walk_p4d_level(pgdp, addr, next, flags);
334 if (rc)
335 break;
336 cond_resched();
337 } while (pgdp++, addr = next, addr < end && !rc);
338 return rc;
339}
340
341static int change_page_attr_alias(unsigned long addr, unsigned long end,
342 unsigned long flags)
343{
344 unsigned long alias, offset, va_start, va_end;
345 struct vm_struct *area;
346 int rc = 0;
347
348 /*
349 * Changes to read-only permissions on kernel VA mappings are also
350 * applied to the kernel direct mapping. Execute permissions are
351 * intentionally not transferred to keep all allocated pages within
352 * the direct mapping non-executable.
353 */
354 flags &= SET_MEMORY_RO | SET_MEMORY_RW;
355 if (!flags)
356 return 0;
357 area = NULL;
358 while (addr < end) {
359 if (!area)
360 area = find_vm_area((void *)addr);
361 if (!area || !(area->flags & VM_ALLOC))
362 return 0;
363 va_start = (unsigned long)area->addr;
364 va_end = va_start + area->nr_pages * PAGE_SIZE;
365 offset = (addr - va_start) >> PAGE_SHIFT;
366 alias = (unsigned long)page_address(area->pages[offset]);
367 rc = change_page_attr(alias, alias + PAGE_SIZE, flags);
368 if (rc)
369 break;
370 addr += PAGE_SIZE;
371 if (addr >= va_end)
372 area = NULL;
373 }
374 return rc;
375}
376
377int __set_memory(unsigned long addr, unsigned long numpages, unsigned long flags)
378{
379 unsigned long end;
380 int rc;
381
382 if (!MACHINE_HAS_NX)
383 flags &= ~(SET_MEMORY_NX | SET_MEMORY_X);
384 if (!flags)
385 return 0;
386 if (!numpages)
387 return 0;
388 addr &= PAGE_MASK;
389 end = addr + numpages * PAGE_SIZE;
390 mutex_lock(&cpa_mutex);
391 rc = change_page_attr(addr, end, flags);
392 if (rc)
393 goto out;
394 rc = change_page_attr_alias(addr, end, flags);
395out:
396 mutex_unlock(&cpa_mutex);
397 return rc;
398}
399
400int set_direct_map_invalid_noflush(struct page *page)
401{
402 return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_INV);
403}
404
405int set_direct_map_default_noflush(struct page *page)
406{
407 return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_DEF);
408}
409
410int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
411{
412 unsigned long flags;
413
414 if (valid)
415 flags = SET_MEMORY_DEF;
416 else
417 flags = SET_MEMORY_INV;
418
419 return __set_memory((unsigned long)page_to_virt(page), nr, flags);
420}
421
422bool kernel_page_present(struct page *page)
423{
424 unsigned long addr;
425 unsigned int cc;
426
427 addr = (unsigned long)page_address(page);
428 asm volatile(
429 " lra %[addr],0(%[addr])\n"
430 CC_IPM(cc)
431 : CC_OUT(cc, cc), [addr] "+a" (addr)
432 :
433 : CC_CLOBBER);
434 return CC_TRANSFORM(cc) == 0;
435}
436
437#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
438
439static void ipte_range(pte_t *pte, unsigned long address, int nr)
440{
441 int i;
442
443 if (test_facility(13)) {
444 __ptep_ipte_range(address, nr - 1, pte, IPTE_GLOBAL);
445 return;
446 }
447 for (i = 0; i < nr; i++) {
448 __ptep_ipte(address, pte, 0, 0, IPTE_GLOBAL);
449 address += PAGE_SIZE;
450 pte++;
451 }
452}
453
454void __kernel_map_pages(struct page *page, int numpages, int enable)
455{
456 unsigned long address;
457 pte_t *ptep, pte;
458 int nr, i, j;
459
460 for (i = 0; i < numpages;) {
461 address = (unsigned long)page_to_virt(page + i);
462 ptep = virt_to_kpte(address);
463 nr = (unsigned long)ptep >> ilog2(sizeof(long));
464 nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1));
465 nr = min(numpages - i, nr);
466 if (enable) {
467 for (j = 0; j < nr; j++) {
468 pte = clear_pte_bit(*ptep, __pgprot(_PAGE_INVALID));
469 set_pte(ptep, pte);
470 address += PAGE_SIZE;
471 ptep++;
472 }
473 } else {
474 ipte_range(ptep, address, nr);
475 }
476 i += nr;
477 }
478}
479
480#endif /* CONFIG_DEBUG_PAGEALLOC */
1/*
2 * Copyright IBM Corp. 2011
3 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
4 */
5#include <linux/hugetlb.h>
6#include <linux/module.h>
7#include <linux/mm.h>
8#include <asm/cacheflush.h>
9#include <asm/facility.h>
10#include <asm/pgtable.h>
11#include <asm/page.h>
12
13#if PAGE_DEFAULT_KEY
14static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
15{
16 asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0"
17 : [addr] "+a" (addr) : [skey] "d" (skey));
18 return addr;
19}
20
21void __storage_key_init_range(unsigned long start, unsigned long end)
22{
23 unsigned long boundary, size;
24
25 while (start < end) {
26 if (MACHINE_HAS_EDAT1) {
27 /* set storage keys for a 1MB frame */
28 size = 1UL << 20;
29 boundary = (start + size) & ~(size - 1);
30 if (boundary <= end) {
31 do {
32 start = sske_frame(start, PAGE_DEFAULT_KEY);
33 } while (start < boundary);
34 continue;
35 }
36 }
37 page_set_storage_key(start, PAGE_DEFAULT_KEY, 0);
38 start += PAGE_SIZE;
39 }
40}
41#endif
42
43static pte_t *walk_page_table(unsigned long addr)
44{
45 pgd_t *pgdp;
46 pud_t *pudp;
47 pmd_t *pmdp;
48 pte_t *ptep;
49
50 pgdp = pgd_offset_k(addr);
51 if (pgd_none(*pgdp))
52 return NULL;
53 pudp = pud_offset(pgdp, addr);
54 if (pud_none(*pudp) || pud_large(*pudp))
55 return NULL;
56 pmdp = pmd_offset(pudp, addr);
57 if (pmd_none(*pmdp) || pmd_large(*pmdp))
58 return NULL;
59 ptep = pte_offset_kernel(pmdp, addr);
60 if (pte_none(*ptep))
61 return NULL;
62 return ptep;
63}
64
65static void change_page_attr(unsigned long addr, int numpages,
66 pte_t (*set) (pte_t))
67{
68 pte_t *ptep;
69 int i;
70
71 for (i = 0; i < numpages; i++) {
72 ptep = walk_page_table(addr);
73 if (WARN_ON_ONCE(!ptep))
74 break;
75 *ptep = set(*ptep);
76 addr += PAGE_SIZE;
77 }
78 __tlb_flush_kernel();
79}
80
81int set_memory_ro(unsigned long addr, int numpages)
82{
83 change_page_attr(addr, numpages, pte_wrprotect);
84 return 0;
85}
86
87int set_memory_rw(unsigned long addr, int numpages)
88{
89 change_page_attr(addr, numpages, pte_mkwrite);
90 return 0;
91}
92
93/* not possible */
94int set_memory_nx(unsigned long addr, int numpages)
95{
96 return 0;
97}
98
99int set_memory_x(unsigned long addr, int numpages)
100{
101 return 0;
102}
103
104#ifdef CONFIG_DEBUG_PAGEALLOC
105
106static void ipte_range(pte_t *pte, unsigned long address, int nr)
107{
108 int i;
109
110 if (test_facility(13)) {
111 __ptep_ipte_range(address, nr - 1, pte);
112 return;
113 }
114 for (i = 0; i < nr; i++) {
115 __ptep_ipte(address, pte);
116 address += PAGE_SIZE;
117 pte++;
118 }
119}
120
121void __kernel_map_pages(struct page *page, int numpages, int enable)
122{
123 unsigned long address;
124 int nr, i, j;
125 pgd_t *pgd;
126 pud_t *pud;
127 pmd_t *pmd;
128 pte_t *pte;
129
130 for (i = 0; i < numpages;) {
131 address = page_to_phys(page + i);
132 pgd = pgd_offset_k(address);
133 pud = pud_offset(pgd, address);
134 pmd = pmd_offset(pud, address);
135 pte = pte_offset_kernel(pmd, address);
136 nr = (unsigned long)pte >> ilog2(sizeof(long));
137 nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1));
138 nr = min(numpages - i, nr);
139 if (enable) {
140 for (j = 0; j < nr; j++) {
141 pte_val(*pte) = __pa(address);
142 address += PAGE_SIZE;
143 pte++;
144 }
145 } else {
146 ipte_range(pte, address, nr);
147 }
148 i += nr;
149 }
150}
151
152#ifdef CONFIG_HIBERNATION
153bool kernel_page_present(struct page *page)
154{
155 unsigned long addr;
156 int cc;
157
158 addr = page_to_phys(page);
159 asm volatile(
160 " lra %1,0(%1)\n"
161 " ipm %0\n"
162 " srl %0,28"
163 : "=d" (cc), "+a" (addr) : : "cc");
164 return cc == 0;
165}
166#endif /* CONFIG_HIBERNATION */
167
168#endif /* CONFIG_DEBUG_PAGEALLOC */