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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Standard user space access functions based on mvcp/mvcs and doing
4 * interesting things in the secondary space mode.
5 *
6 * Copyright IBM Corp. 2006,2014
7 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
8 * Gerald Schaefer (gerald.schaefer@de.ibm.com)
9 */
10
11#include <linux/jump_label.h>
12#include <linux/uaccess.h>
13#include <linux/export.h>
14#include <linux/errno.h>
15#include <linux/mm.h>
16#include <asm/mmu_context.h>
17#include <asm/facility.h>
18
19#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
20static DEFINE_STATIC_KEY_FALSE(have_mvcos);
21
22static int __init uaccess_init(void)
23{
24 if (test_facility(27))
25 static_branch_enable(&have_mvcos);
26 return 0;
27}
28early_initcall(uaccess_init);
29
30static inline int copy_with_mvcos(void)
31{
32 if (static_branch_likely(&have_mvcos))
33 return 1;
34 return 0;
35}
36#else
37static inline int copy_with_mvcos(void)
38{
39 return 1;
40}
41#endif
42
43void set_fs(mm_segment_t fs)
44{
45 current->thread.mm_segment = fs;
46 if (fs == USER_DS) {
47 __ctl_load(S390_lowcore.user_asce, 1, 1);
48 clear_cpu_flag(CIF_ASCE_PRIMARY);
49 } else {
50 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
51 set_cpu_flag(CIF_ASCE_PRIMARY);
52 }
53 if (fs & 1) {
54 if (fs == USER_DS_SACF)
55 __ctl_load(S390_lowcore.user_asce, 7, 7);
56 else
57 __ctl_load(S390_lowcore.kernel_asce, 7, 7);
58 set_cpu_flag(CIF_ASCE_SECONDARY);
59 }
60}
61EXPORT_SYMBOL(set_fs);
62
63mm_segment_t enable_sacf_uaccess(void)
64{
65 mm_segment_t old_fs;
66 unsigned long asce, cr;
67
68 old_fs = current->thread.mm_segment;
69 if (old_fs & 1)
70 return old_fs;
71 current->thread.mm_segment |= 1;
72 asce = S390_lowcore.kernel_asce;
73 if (likely(old_fs == USER_DS)) {
74 __ctl_store(cr, 1, 1);
75 if (cr != S390_lowcore.kernel_asce) {
76 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
77 set_cpu_flag(CIF_ASCE_PRIMARY);
78 }
79 asce = S390_lowcore.user_asce;
80 }
81 __ctl_store(cr, 7, 7);
82 if (cr != asce) {
83 __ctl_load(asce, 7, 7);
84 set_cpu_flag(CIF_ASCE_SECONDARY);
85 }
86 return old_fs;
87}
88EXPORT_SYMBOL(enable_sacf_uaccess);
89
90void disable_sacf_uaccess(mm_segment_t old_fs)
91{
92 current->thread.mm_segment = old_fs;
93 if (old_fs == USER_DS && test_facility(27)) {
94 __ctl_load(S390_lowcore.user_asce, 1, 1);
95 clear_cpu_flag(CIF_ASCE_PRIMARY);
96 }
97}
98EXPORT_SYMBOL(disable_sacf_uaccess);
99
100static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
101 unsigned long size)
102{
103 register unsigned long reg0 asm("0") = 0x01UL;
104 unsigned long tmp1, tmp2;
105
106 tmp1 = -4096UL;
107 asm volatile(
108 "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
109 "6: jz 4f\n"
110 "1: algr %0,%3\n"
111 " slgr %1,%3\n"
112 " slgr %2,%3\n"
113 " j 0b\n"
114 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
115 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
116 " slgr %4,%1\n"
117 " clgr %0,%4\n" /* copy crosses next page boundary? */
118 " jnh 5f\n"
119 "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
120 "7: slgr %0,%4\n"
121 " j 5f\n"
122 "4: slgr %0,%0\n"
123 "5:\n"
124 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
125 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
126 : "d" (reg0) : "cc", "memory");
127 return size;
128}
129
130static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
131 unsigned long size)
132{
133 unsigned long tmp1, tmp2;
134 mm_segment_t old_fs;
135
136 old_fs = enable_sacf_uaccess();
137 tmp1 = -256UL;
138 asm volatile(
139 " sacf 0\n"
140 "0: mvcp 0(%0,%2),0(%1),%3\n"
141 "7: jz 5f\n"
142 "1: algr %0,%3\n"
143 " la %1,256(%1)\n"
144 " la %2,256(%2)\n"
145 "2: mvcp 0(%0,%2),0(%1),%3\n"
146 "8: jnz 1b\n"
147 " j 5f\n"
148 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
149 " lghi %3,-4096\n"
150 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
151 " slgr %4,%1\n"
152 " clgr %0,%4\n" /* copy crosses next page boundary? */
153 " jnh 6f\n"
154 "4: mvcp 0(%4,%2),0(%1),%3\n"
155 "9: slgr %0,%4\n"
156 " j 6f\n"
157 "5: slgr %0,%0\n"
158 "6: sacf 768\n"
159 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
160 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
161 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
162 : : "cc", "memory");
163 disable_sacf_uaccess(old_fs);
164 return size;
165}
166
167unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
168{
169 if (copy_with_mvcos())
170 return copy_from_user_mvcos(to, from, n);
171 return copy_from_user_mvcp(to, from, n);
172}
173EXPORT_SYMBOL(raw_copy_from_user);
174
175static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
176 unsigned long size)
177{
178 register unsigned long reg0 asm("0") = 0x010000UL;
179 unsigned long tmp1, tmp2;
180
181 tmp1 = -4096UL;
182 asm volatile(
183 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
184 "6: jz 4f\n"
185 "1: algr %0,%3\n"
186 " slgr %1,%3\n"
187 " slgr %2,%3\n"
188 " j 0b\n"
189 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
190 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
191 " slgr %4,%1\n"
192 " clgr %0,%4\n" /* copy crosses next page boundary? */
193 " jnh 5f\n"
194 "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
195 "7: slgr %0,%4\n"
196 " j 5f\n"
197 "4: slgr %0,%0\n"
198 "5:\n"
199 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
200 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
201 : "d" (reg0) : "cc", "memory");
202 return size;
203}
204
205static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
206 unsigned long size)
207{
208 unsigned long tmp1, tmp2;
209 mm_segment_t old_fs;
210
211 old_fs = enable_sacf_uaccess();
212 tmp1 = -256UL;
213 asm volatile(
214 " sacf 0\n"
215 "0: mvcs 0(%0,%1),0(%2),%3\n"
216 "7: jz 5f\n"
217 "1: algr %0,%3\n"
218 " la %1,256(%1)\n"
219 " la %2,256(%2)\n"
220 "2: mvcs 0(%0,%1),0(%2),%3\n"
221 "8: jnz 1b\n"
222 " j 5f\n"
223 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
224 " lghi %3,-4096\n"
225 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
226 " slgr %4,%1\n"
227 " clgr %0,%4\n" /* copy crosses next page boundary? */
228 " jnh 6f\n"
229 "4: mvcs 0(%4,%1),0(%2),%3\n"
230 "9: slgr %0,%4\n"
231 " j 6f\n"
232 "5: slgr %0,%0\n"
233 "6: sacf 768\n"
234 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
235 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
236 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
237 : : "cc", "memory");
238 disable_sacf_uaccess(old_fs);
239 return size;
240}
241
242unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
243{
244 if (copy_with_mvcos())
245 return copy_to_user_mvcos(to, from, n);
246 return copy_to_user_mvcs(to, from, n);
247}
248EXPORT_SYMBOL(raw_copy_to_user);
249
250static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
251 unsigned long size)
252{
253 register unsigned long reg0 asm("0") = 0x010001UL;
254 unsigned long tmp1, tmp2;
255
256 tmp1 = -4096UL;
257 /* FIXME: copy with reduced length. */
258 asm volatile(
259 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
260 " jz 2f\n"
261 "1: algr %0,%3\n"
262 " slgr %1,%3\n"
263 " slgr %2,%3\n"
264 " j 0b\n"
265 "2:slgr %0,%0\n"
266 "3: \n"
267 EX_TABLE(0b,3b)
268 : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
269 : "d" (reg0) : "cc", "memory");
270 return size;
271}
272
273static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
274 unsigned long size)
275{
276 mm_segment_t old_fs;
277 unsigned long tmp1;
278
279 old_fs = enable_sacf_uaccess();
280 asm volatile(
281 " sacf 256\n"
282 " aghi %0,-1\n"
283 " jo 5f\n"
284 " bras %3,3f\n"
285 "0: aghi %0,257\n"
286 "1: mvc 0(1,%1),0(%2)\n"
287 " la %1,1(%1)\n"
288 " la %2,1(%2)\n"
289 " aghi %0,-1\n"
290 " jnz 1b\n"
291 " j 5f\n"
292 "2: mvc 0(256,%1),0(%2)\n"
293 " la %1,256(%1)\n"
294 " la %2,256(%2)\n"
295 "3: aghi %0,-256\n"
296 " jnm 2b\n"
297 "4: ex %0,1b-0b(%3)\n"
298 "5: slgr %0,%0\n"
299 "6: sacf 768\n"
300 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
301 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
302 : : "cc", "memory");
303 disable_sacf_uaccess(old_fs);
304 return size;
305}
306
307unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
308{
309 if (copy_with_mvcos())
310 return copy_in_user_mvcos(to, from, n);
311 return copy_in_user_mvc(to, from, n);
312}
313EXPORT_SYMBOL(raw_copy_in_user);
314
315static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
316{
317 register unsigned long reg0 asm("0") = 0x010000UL;
318 unsigned long tmp1, tmp2;
319
320 tmp1 = -4096UL;
321 asm volatile(
322 "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
323 " jz 4f\n"
324 "1: algr %0,%2\n"
325 " slgr %1,%2\n"
326 " j 0b\n"
327 "2: la %3,4095(%1)\n"/* %4 = to + 4095 */
328 " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
329 " slgr %3,%1\n"
330 " clgr %0,%3\n" /* copy crosses next page boundary? */
331 " jnh 5f\n"
332 "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
333 " slgr %0,%3\n"
334 " j 5f\n"
335 "4: slgr %0,%0\n"
336 "5:\n"
337 EX_TABLE(0b,2b) EX_TABLE(3b,5b)
338 : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
339 : "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
340 return size;
341}
342
343static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
344{
345 mm_segment_t old_fs;
346 unsigned long tmp1, tmp2;
347
348 old_fs = enable_sacf_uaccess();
349 asm volatile(
350 " sacf 256\n"
351 " aghi %0,-1\n"
352 " jo 5f\n"
353 " bras %3,3f\n"
354 " xc 0(1,%1),0(%1)\n"
355 "0: aghi %0,257\n"
356 " la %2,255(%1)\n" /* %2 = ptr + 255 */
357 " srl %2,12\n"
358 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
359 " slgr %2,%1\n"
360 " clgr %0,%2\n" /* clear crosses next page boundary? */
361 " jnh 5f\n"
362 " aghi %2,-1\n"
363 "1: ex %2,0(%3)\n"
364 " aghi %2,1\n"
365 " slgr %0,%2\n"
366 " j 5f\n"
367 "2: xc 0(256,%1),0(%1)\n"
368 " la %1,256(%1)\n"
369 "3: aghi %0,-256\n"
370 " jnm 2b\n"
371 "4: ex %0,0(%3)\n"
372 "5: slgr %0,%0\n"
373 "6: sacf 768\n"
374 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
375 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
376 : : "cc", "memory");
377 disable_sacf_uaccess(old_fs);
378 return size;
379}
380
381unsigned long __clear_user(void __user *to, unsigned long size)
382{
383 if (copy_with_mvcos())
384 return clear_user_mvcos(to, size);
385 return clear_user_xc(to, size);
386}
387EXPORT_SYMBOL(__clear_user);
388
389static inline unsigned long strnlen_user_srst(const char __user *src,
390 unsigned long size)
391{
392 register unsigned long reg0 asm("0") = 0;
393 unsigned long tmp1, tmp2;
394
395 asm volatile(
396 " la %2,0(%1)\n"
397 " la %3,0(%0,%1)\n"
398 " slgr %0,%0\n"
399 " sacf 256\n"
400 "0: srst %3,%2\n"
401 " jo 0b\n"
402 " la %0,1(%3)\n" /* strnlen_user results includes \0 */
403 " slgr %0,%1\n"
404 "1: sacf 768\n"
405 EX_TABLE(0b,1b)
406 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
407 : "d" (reg0) : "cc", "memory");
408 return size;
409}
410
411unsigned long __strnlen_user(const char __user *src, unsigned long size)
412{
413 mm_segment_t old_fs;
414 unsigned long len;
415
416 if (unlikely(!size))
417 return 0;
418 old_fs = enable_sacf_uaccess();
419 len = strnlen_user_srst(src, size);
420 disable_sacf_uaccess(old_fs);
421 return len;
422}
423EXPORT_SYMBOL(__strnlen_user);
424
425long __strncpy_from_user(char *dst, const char __user *src, long size)
426{
427 size_t done, len, offset, len_str;
428
429 if (unlikely(size <= 0))
430 return 0;
431 done = 0;
432 do {
433 offset = (size_t)src & (L1_CACHE_BYTES - 1);
434 len = min(size - done, L1_CACHE_BYTES - offset);
435 if (copy_from_user(dst, src, len))
436 return -EFAULT;
437 len_str = strnlen(dst, len);
438 done += len_str;
439 src += len_str;
440 dst += len_str;
441 } while ((len_str == len) && (done < size));
442 return done;
443}
444EXPORT_SYMBOL(__strncpy_from_user);
1/*
2 * Standard user space access functions based on mvcp/mvcs and doing
3 * interesting things in the secondary space mode.
4 *
5 * Copyright IBM Corp. 2006,2014
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7 * Gerald Schaefer (gerald.schaefer@de.ibm.com)
8 */
9
10#include <linux/jump_label.h>
11#include <linux/uaccess.h>
12#include <linux/export.h>
13#include <linux/errno.h>
14#include <linux/mm.h>
15#include <asm/mmu_context.h>
16#include <asm/facility.h>
17
18#ifndef CONFIG_64BIT
19#define AHI "ahi"
20#define ALR "alr"
21#define CLR "clr"
22#define LHI "lhi"
23#define SLR "slr"
24#else
25#define AHI "aghi"
26#define ALR "algr"
27#define CLR "clgr"
28#define LHI "lghi"
29#define SLR "slgr"
30#endif
31
32static struct static_key have_mvcos = STATIC_KEY_INIT_FALSE;
33
34static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
35 unsigned long size)
36{
37 register unsigned long reg0 asm("0") = 0x81UL;
38 unsigned long tmp1, tmp2;
39
40 tmp1 = -4096UL;
41 asm volatile(
42 "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
43 "9: jz 7f\n"
44 "1:"ALR" %0,%3\n"
45 " "SLR" %1,%3\n"
46 " "SLR" %2,%3\n"
47 " j 0b\n"
48 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
49 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
50 " "SLR" %4,%1\n"
51 " "CLR" %0,%4\n" /* copy crosses next page boundary? */
52 " jnh 4f\n"
53 "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
54 "10:"SLR" %0,%4\n"
55 " "ALR" %2,%4\n"
56 "4:"LHI" %4,-1\n"
57 " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
58 " bras %3,6f\n" /* memset loop */
59 " xc 0(1,%2),0(%2)\n"
60 "5: xc 0(256,%2),0(%2)\n"
61 " la %2,256(%2)\n"
62 "6:"AHI" %4,-256\n"
63 " jnm 5b\n"
64 " ex %4,0(%3)\n"
65 " j 8f\n"
66 "7:"SLR" %0,%0\n"
67 "8:\n"
68 EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
69 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
70 : "d" (reg0) : "cc", "memory");
71 return size;
72}
73
74static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
75 unsigned long size)
76{
77 unsigned long tmp1, tmp2;
78
79 update_primary_asce(current);
80 tmp1 = -256UL;
81 asm volatile(
82 " sacf 0\n"
83 "0: mvcp 0(%0,%2),0(%1),%3\n"
84 "10:jz 8f\n"
85 "1:"ALR" %0,%3\n"
86 " la %1,256(%1)\n"
87 " la %2,256(%2)\n"
88 "2: mvcp 0(%0,%2),0(%1),%3\n"
89 "11:jnz 1b\n"
90 " j 8f\n"
91 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
92 " "LHI" %3,-4096\n"
93 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
94 " "SLR" %4,%1\n"
95 " "CLR" %0,%4\n" /* copy crosses next page boundary? */
96 " jnh 5f\n"
97 "4: mvcp 0(%4,%2),0(%1),%3\n"
98 "12:"SLR" %0,%4\n"
99 " "ALR" %2,%4\n"
100 "5:"LHI" %4,-1\n"
101 " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
102 " bras %3,7f\n" /* memset loop */
103 " xc 0(1,%2),0(%2)\n"
104 "6: xc 0(256,%2),0(%2)\n"
105 " la %2,256(%2)\n"
106 "7:"AHI" %4,-256\n"
107 " jnm 6b\n"
108 " ex %4,0(%3)\n"
109 " j 9f\n"
110 "8:"SLR" %0,%0\n"
111 "9: sacf 768\n"
112 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
113 EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
114 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
115 : : "cc", "memory");
116 return size;
117}
118
119unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
120{
121 if (static_key_false(&have_mvcos))
122 return copy_from_user_mvcos(to, from, n);
123 return copy_from_user_mvcp(to, from, n);
124}
125EXPORT_SYMBOL(__copy_from_user);
126
127static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
128 unsigned long size)
129{
130 register unsigned long reg0 asm("0") = 0x810000UL;
131 unsigned long tmp1, tmp2;
132
133 tmp1 = -4096UL;
134 asm volatile(
135 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
136 "6: jz 4f\n"
137 "1:"ALR" %0,%3\n"
138 " "SLR" %1,%3\n"
139 " "SLR" %2,%3\n"
140 " j 0b\n"
141 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
142 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
143 " "SLR" %4,%1\n"
144 " "CLR" %0,%4\n" /* copy crosses next page boundary? */
145 " jnh 5f\n"
146 "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
147 "7:"SLR" %0,%4\n"
148 " j 5f\n"
149 "4:"SLR" %0,%0\n"
150 "5:\n"
151 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
152 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
153 : "d" (reg0) : "cc", "memory");
154 return size;
155}
156
157static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
158 unsigned long size)
159{
160 unsigned long tmp1, tmp2;
161
162 update_primary_asce(current);
163 tmp1 = -256UL;
164 asm volatile(
165 " sacf 0\n"
166 "0: mvcs 0(%0,%1),0(%2),%3\n"
167 "7: jz 5f\n"
168 "1:"ALR" %0,%3\n"
169 " la %1,256(%1)\n"
170 " la %2,256(%2)\n"
171 "2: mvcs 0(%0,%1),0(%2),%3\n"
172 "8: jnz 1b\n"
173 " j 5f\n"
174 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
175 " "LHI" %3,-4096\n"
176 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
177 " "SLR" %4,%1\n"
178 " "CLR" %0,%4\n" /* copy crosses next page boundary? */
179 " jnh 6f\n"
180 "4: mvcs 0(%4,%1),0(%2),%3\n"
181 "9:"SLR" %0,%4\n"
182 " j 6f\n"
183 "5:"SLR" %0,%0\n"
184 "6: sacf 768\n"
185 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
186 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
187 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
188 : : "cc", "memory");
189 return size;
190}
191
192unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
193{
194 if (static_key_false(&have_mvcos))
195 return copy_to_user_mvcos(to, from, n);
196 return copy_to_user_mvcs(to, from, n);
197}
198EXPORT_SYMBOL(__copy_to_user);
199
200static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
201 unsigned long size)
202{
203 register unsigned long reg0 asm("0") = 0x810081UL;
204 unsigned long tmp1, tmp2;
205
206 tmp1 = -4096UL;
207 /* FIXME: copy with reduced length. */
208 asm volatile(
209 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
210 " jz 2f\n"
211 "1:"ALR" %0,%3\n"
212 " "SLR" %1,%3\n"
213 " "SLR" %2,%3\n"
214 " j 0b\n"
215 "2:"SLR" %0,%0\n"
216 "3: \n"
217 EX_TABLE(0b,3b)
218 : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
219 : "d" (reg0) : "cc", "memory");
220 return size;
221}
222
223static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
224 unsigned long size)
225{
226 unsigned long tmp1;
227
228 update_primary_asce(current);
229 asm volatile(
230 " sacf 256\n"
231 " "AHI" %0,-1\n"
232 " jo 5f\n"
233 " bras %3,3f\n"
234 "0:"AHI" %0,257\n"
235 "1: mvc 0(1,%1),0(%2)\n"
236 " la %1,1(%1)\n"
237 " la %2,1(%2)\n"
238 " "AHI" %0,-1\n"
239 " jnz 1b\n"
240 " j 5f\n"
241 "2: mvc 0(256,%1),0(%2)\n"
242 " la %1,256(%1)\n"
243 " la %2,256(%2)\n"
244 "3:"AHI" %0,-256\n"
245 " jnm 2b\n"
246 "4: ex %0,1b-0b(%3)\n"
247 "5: "SLR" %0,%0\n"
248 "6: sacf 768\n"
249 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
250 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
251 : : "cc", "memory");
252 return size;
253}
254
255unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n)
256{
257 if (static_key_false(&have_mvcos))
258 return copy_in_user_mvcos(to, from, n);
259 return copy_in_user_mvc(to, from, n);
260}
261EXPORT_SYMBOL(__copy_in_user);
262
263static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
264{
265 register unsigned long reg0 asm("0") = 0x810000UL;
266 unsigned long tmp1, tmp2;
267
268 tmp1 = -4096UL;
269 asm volatile(
270 "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
271 " jz 4f\n"
272 "1:"ALR" %0,%2\n"
273 " "SLR" %1,%2\n"
274 " j 0b\n"
275 "2: la %3,4095(%1)\n"/* %4 = to + 4095 */
276 " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
277 " "SLR" %3,%1\n"
278 " "CLR" %0,%3\n" /* copy crosses next page boundary? */
279 " jnh 5f\n"
280 "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
281 " "SLR" %0,%3\n"
282 " j 5f\n"
283 "4:"SLR" %0,%0\n"
284 "5:\n"
285 EX_TABLE(0b,2b) EX_TABLE(3b,5b)
286 : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
287 : "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
288 return size;
289}
290
291static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
292{
293 unsigned long tmp1, tmp2;
294
295 update_primary_asce(current);
296 asm volatile(
297 " sacf 256\n"
298 " "AHI" %0,-1\n"
299 " jo 5f\n"
300 " bras %3,3f\n"
301 " xc 0(1,%1),0(%1)\n"
302 "0:"AHI" %0,257\n"
303 " la %2,255(%1)\n" /* %2 = ptr + 255 */
304 " srl %2,12\n"
305 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
306 " "SLR" %2,%1\n"
307 " "CLR" %0,%2\n" /* clear crosses next page boundary? */
308 " jnh 5f\n"
309 " "AHI" %2,-1\n"
310 "1: ex %2,0(%3)\n"
311 " "AHI" %2,1\n"
312 " "SLR" %0,%2\n"
313 " j 5f\n"
314 "2: xc 0(256,%1),0(%1)\n"
315 " la %1,256(%1)\n"
316 "3:"AHI" %0,-256\n"
317 " jnm 2b\n"
318 "4: ex %0,0(%3)\n"
319 "5: "SLR" %0,%0\n"
320 "6: sacf 768\n"
321 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
322 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
323 : : "cc", "memory");
324 return size;
325}
326
327unsigned long __clear_user(void __user *to, unsigned long size)
328{
329 if (static_key_false(&have_mvcos))
330 return clear_user_mvcos(to, size);
331 return clear_user_xc(to, size);
332}
333EXPORT_SYMBOL(__clear_user);
334
335static inline unsigned long strnlen_user_srst(const char __user *src,
336 unsigned long size)
337{
338 register unsigned long reg0 asm("0") = 0;
339 unsigned long tmp1, tmp2;
340
341 asm volatile(
342 " la %2,0(%1)\n"
343 " la %3,0(%0,%1)\n"
344 " "SLR" %0,%0\n"
345 " sacf 256\n"
346 "0: srst %3,%2\n"
347 " jo 0b\n"
348 " la %0,1(%3)\n" /* strnlen_user results includes \0 */
349 " "SLR" %0,%1\n"
350 "1: sacf 768\n"
351 EX_TABLE(0b,1b)
352 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
353 : "d" (reg0) : "cc", "memory");
354 return size;
355}
356
357unsigned long __strnlen_user(const char __user *src, unsigned long size)
358{
359 if (unlikely(!size))
360 return 0;
361 update_primary_asce(current);
362 return strnlen_user_srst(src, size);
363}
364EXPORT_SYMBOL(__strnlen_user);
365
366long __strncpy_from_user(char *dst, const char __user *src, long size)
367{
368 size_t done, len, offset, len_str;
369
370 if (unlikely(size <= 0))
371 return 0;
372 done = 0;
373 do {
374 offset = (size_t)src & ~PAGE_MASK;
375 len = min(size - done, PAGE_SIZE - offset);
376 if (copy_from_user(dst, src, len))
377 return -EFAULT;
378 len_str = strnlen(dst, len);
379 done += len_str;
380 src += len_str;
381 dst += len_str;
382 } while ((len_str == len) && (done < size));
383 return done;
384}
385EXPORT_SYMBOL(__strncpy_from_user);
386
387/*
388 * The "old" uaccess variant without mvcos can be enforced with the
389 * uaccess_primary kernel parameter. This is mainly for debugging purposes.
390 */
391static int uaccess_primary __initdata;
392
393static int __init parse_uaccess_pt(char *__unused)
394{
395 uaccess_primary = 1;
396 return 0;
397}
398early_param("uaccess_primary", parse_uaccess_pt);
399
400static int __init uaccess_init(void)
401{
402 if (IS_ENABLED(CONFIG_64BIT) && !uaccess_primary && test_facility(27))
403 static_key_slow_inc(&have_mvcos);
404 return 0;
405}
406early_initcall(uaccess_init);