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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001// SPDX-License-Identifier: GPL-2.0
Heiko Carstens457f2182014-03-21 10:42:25 +01002/*
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
Sven Schnelle56e62a72020-11-21 11:14:56 +010019#ifdef CONFIG_DEBUG_ENTRY
20void debug_user_asce(int exit)
Heiko Carstens062e5272020-11-16 08:06:41 +010021{
22 unsigned long cr1, cr7;
23
24 __ctl_store(cr1, 1, 1);
25 __ctl_store(cr7, 7, 7);
26 if (cr1 == S390_lowcore.kernel_asce && cr7 == S390_lowcore.user_asce)
27 return;
Sven Schnelle56e62a72020-11-21 11:14:56 +010028 panic("incorrect ASCE on kernel %s\n"
Heiko Carstens062e5272020-11-16 08:06:41 +010029 "cr1: %016lx cr7: %016lx\n"
30 "kernel: %016llx user: %016llx\n",
Sven Schnelle56e62a72020-11-21 11:14:56 +010031 exit ? "exit" : "entry", cr1, cr7,
32 S390_lowcore.kernel_asce, S390_lowcore.user_asce);
33
Heiko Carstens062e5272020-11-16 08:06:41 +010034}
Sven Schnelle56e62a72020-11-21 11:14:56 +010035#endif /*CONFIG_DEBUG_ENTRY */
Heiko Carstens062e5272020-11-16 08:06:41 +010036
Martin Schwidefskyd66bf802017-08-21 14:47:04 +020037#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
Heiko Carstensed79e942015-07-29 08:31:24 +020038static DEFINE_STATIC_KEY_FALSE(have_mvcos);
Heiko Carstens457f2182014-03-21 10:42:25 +010039
Martin Schwidefskyd66bf802017-08-21 14:47:04 +020040static int __init uaccess_init(void)
41{
42 if (test_facility(27))
43 static_branch_enable(&have_mvcos);
44 return 0;
45}
46early_initcall(uaccess_init);
47
48static inline int copy_with_mvcos(void)
49{
50 if (static_branch_likely(&have_mvcos))
51 return 1;
52 return 0;
53}
54#else
55static inline int copy_with_mvcos(void)
56{
57 return 1;
58}
59#endif
60
Heiko Carstens457f2182014-03-21 10:42:25 +010061static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
62 unsigned long size)
63{
Heiko Carstens457f2182014-03-21 10:42:25 +010064 unsigned long tmp1, tmp2;
Nico Boehr012a2242022-01-11 11:00:03 +010065 union oac spec = {
66 .oac2.as = PSW_BITS_AS_SECONDARY,
67 .oac2.a = 1,
68 };
Heiko Carstens457f2182014-03-21 10:42:25 +010069
70 tmp1 = -4096UL;
71 asm volatile(
Nico Boehr012a2242022-01-11 11:00:03 +010072 " lr 0,%[spec]\n"
Heiko Carstens457f2182014-03-21 10:42:25 +010073 "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
Al Viro37096002017-03-28 15:06:24 -040074 "6: jz 4f\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +010075 "1: algr %0,%3\n"
76 " slgr %1,%3\n"
77 " slgr %2,%3\n"
Heiko Carstens457f2182014-03-21 10:42:25 +010078 " j 0b\n"
79 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
80 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
Heiko Carstens5a79859a2015-02-12 13:08:27 +010081 " slgr %4,%1\n"
82 " clgr %0,%4\n" /* copy crosses next page boundary? */
Al Viro37096002017-03-28 15:06:24 -040083 " jnh 5f\n"
Heiko Carstens457f2182014-03-21 10:42:25 +010084 "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
Al Viro37096002017-03-28 15:06:24 -040085 "7: slgr %0,%4\n"
86 " j 5f\n"
87 "4: slgr %0,%0\n"
88 "5:\n"
89 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
Heiko Carstens457f2182014-03-21 10:42:25 +010090 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
Nico Boehr012a2242022-01-11 11:00:03 +010091 : [spec] "d" (spec.val)
Heiko Carstensd1e18ef2021-06-21 13:38:45 +020092 : "cc", "memory", "0");
Heiko Carstens457f2182014-03-21 10:42:25 +010093 return size;
94}
95
96static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
97 unsigned long size)
98{
99 unsigned long tmp1, tmp2;
100
Heiko Carstens457f2182014-03-21 10:42:25 +0100101 tmp1 = -256UL;
102 asm volatile(
103 " sacf 0\n"
104 "0: mvcp 0(%0,%2),0(%1),%3\n"
Al Viro37096002017-03-28 15:06:24 -0400105 "7: jz 5f\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100106 "1: algr %0,%3\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100107 " la %1,256(%1)\n"
108 " la %2,256(%2)\n"
109 "2: mvcp 0(%0,%2),0(%1),%3\n"
Al Viro37096002017-03-28 15:06:24 -0400110 "8: jnz 1b\n"
111 " j 5f\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100112 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100113 " lghi %3,-4096\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100114 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100115 " slgr %4,%1\n"
116 " clgr %0,%4\n" /* copy crosses next page boundary? */
Al Viro37096002017-03-28 15:06:24 -0400117 " jnh 6f\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100118 "4: mvcp 0(%4,%2),0(%1),%3\n"
Al Viro37096002017-03-28 15:06:24 -0400119 "9: slgr %0,%4\n"
120 " j 6f\n"
121 "5: slgr %0,%0\n"
122 "6: sacf 768\n"
123 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
124 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
Heiko Carstens457f2182014-03-21 10:42:25 +0100125 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
126 : : "cc", "memory");
127 return size;
128}
129
Al Viro37096002017-03-28 15:06:24 -0400130unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
Heiko Carstens457f2182014-03-21 10:42:25 +0100131{
Martin Schwidefskyd66bf802017-08-21 14:47:04 +0200132 if (copy_with_mvcos())
Heiko Carstens457f2182014-03-21 10:42:25 +0100133 return copy_from_user_mvcos(to, from, n);
134 return copy_from_user_mvcp(to, from, n);
135}
Al Viro37096002017-03-28 15:06:24 -0400136EXPORT_SYMBOL(raw_copy_from_user);
Heiko Carstens457f2182014-03-21 10:42:25 +0100137
138static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
139 unsigned long size)
140{
Heiko Carstens457f2182014-03-21 10:42:25 +0100141 unsigned long tmp1, tmp2;
Nico Boehr012a2242022-01-11 11:00:03 +0100142 union oac spec = {
143 .oac1.as = PSW_BITS_AS_SECONDARY,
144 .oac1.a = 1,
145 };
Heiko Carstens457f2182014-03-21 10:42:25 +0100146
147 tmp1 = -4096UL;
148 asm volatile(
Nico Boehr012a2242022-01-11 11:00:03 +0100149 " lr 0,%[spec]\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100150 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
151 "6: jz 4f\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100152 "1: algr %0,%3\n"
153 " slgr %1,%3\n"
154 " slgr %2,%3\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100155 " j 0b\n"
156 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
157 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100158 " slgr %4,%1\n"
159 " clgr %0,%4\n" /* copy crosses next page boundary? */
Heiko Carstens457f2182014-03-21 10:42:25 +0100160 " jnh 5f\n"
161 "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100162 "7: slgr %0,%4\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100163 " j 5f\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100164 "4: slgr %0,%0\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100165 "5:\n"
166 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
167 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
Nico Boehr012a2242022-01-11 11:00:03 +0100168 : [spec] "d" (spec.val)
Heiko Carstensd1e18ef2021-06-21 13:38:45 +0200169 : "cc", "memory", "0");
Heiko Carstens457f2182014-03-21 10:42:25 +0100170 return size;
171}
172
173static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
174 unsigned long size)
175{
176 unsigned long tmp1, tmp2;
177
Heiko Carstens457f2182014-03-21 10:42:25 +0100178 tmp1 = -256UL;
179 asm volatile(
180 " sacf 0\n"
181 "0: mvcs 0(%0,%1),0(%2),%3\n"
182 "7: jz 5f\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100183 "1: algr %0,%3\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100184 " la %1,256(%1)\n"
185 " la %2,256(%2)\n"
186 "2: mvcs 0(%0,%1),0(%2),%3\n"
187 "8: jnz 1b\n"
188 " j 5f\n"
189 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100190 " lghi %3,-4096\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100191 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100192 " slgr %4,%1\n"
193 " clgr %0,%4\n" /* copy crosses next page boundary? */
Heiko Carstens457f2182014-03-21 10:42:25 +0100194 " jnh 6f\n"
195 "4: mvcs 0(%4,%1),0(%2),%3\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100196 "9: slgr %0,%4\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100197 " j 6f\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100198 "5: slgr %0,%0\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100199 "6: sacf 768\n"
200 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
201 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
202 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
203 : : "cc", "memory");
204 return size;
205}
206
Al Viro37096002017-03-28 15:06:24 -0400207unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
Heiko Carstens457f2182014-03-21 10:42:25 +0100208{
Martin Schwidefskyd66bf802017-08-21 14:47:04 +0200209 if (copy_with_mvcos())
Heiko Carstens457f2182014-03-21 10:42:25 +0100210 return copy_to_user_mvcos(to, from, n);
211 return copy_to_user_mvcs(to, from, n);
212}
Al Viro37096002017-03-28 15:06:24 -0400213EXPORT_SYMBOL(raw_copy_to_user);
Heiko Carstens457f2182014-03-21 10:42:25 +0100214
Heiko Carstens457f2182014-03-21 10:42:25 +0100215static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
216{
Heiko Carstens457f2182014-03-21 10:42:25 +0100217 unsigned long tmp1, tmp2;
Nico Boehr012a2242022-01-11 11:00:03 +0100218 union oac spec = {
219 .oac1.as = PSW_BITS_AS_SECONDARY,
220 .oac1.a = 1,
221 };
Heiko Carstens457f2182014-03-21 10:42:25 +0100222
223 tmp1 = -4096UL;
224 asm volatile(
Nico Boehr012a2242022-01-11 11:00:03 +0100225 " lr 0,%[spec]\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100226 "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
227 " jz 4f\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100228 "1: algr %0,%2\n"
229 " slgr %1,%2\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100230 " j 0b\n"
231 "2: la %3,4095(%1)\n"/* %4 = to + 4095 */
232 " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100233 " slgr %3,%1\n"
234 " clgr %0,%3\n" /* copy crosses next page boundary? */
Heiko Carstens457f2182014-03-21 10:42:25 +0100235 " jnh 5f\n"
236 "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100237 " slgr %0,%3\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100238 " j 5f\n"
Heiko Carstensb8ac5e22016-06-10 09:35:51 +0200239 "4: slgr %0,%0\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100240 "5:\n"
241 EX_TABLE(0b,2b) EX_TABLE(3b,5b)
242 : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
Nico Boehr012a2242022-01-11 11:00:03 +0100243 : "a" (empty_zero_page), [spec] "d" (spec.val)
Heiko Carstensd1e18ef2021-06-21 13:38:45 +0200244 : "cc", "memory", "0");
Heiko Carstens457f2182014-03-21 10:42:25 +0100245 return size;
246}
247
248static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
249{
250 unsigned long tmp1, tmp2;
251
Heiko Carstens457f2182014-03-21 10:42:25 +0100252 asm volatile(
253 " sacf 256\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100254 " aghi %0,-1\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100255 " jo 5f\n"
256 " bras %3,3f\n"
257 " xc 0(1,%1),0(%1)\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100258 "0: aghi %0,257\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100259 " la %2,255(%1)\n" /* %2 = ptr + 255 */
260 " srl %2,12\n"
261 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100262 " slgr %2,%1\n"
263 " clgr %0,%2\n" /* clear crosses next page boundary? */
Heiko Carstens457f2182014-03-21 10:42:25 +0100264 " jnh 5f\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100265 " aghi %2,-1\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100266 "1: ex %2,0(%3)\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100267 " aghi %2,1\n"
268 " slgr %0,%2\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100269 " j 5f\n"
270 "2: xc 0(256,%1),0(%1)\n"
271 " la %1,256(%1)\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100272 "3: aghi %0,-256\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100273 " jnm 2b\n"
274 "4: ex %0,0(%3)\n"
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100275 "5: slgr %0,%0\n"
Heiko Carstens457f2182014-03-21 10:42:25 +0100276 "6: sacf 768\n"
277 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
278 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
279 : : "cc", "memory");
280 return size;
281}
282
283unsigned long __clear_user(void __user *to, unsigned long size)
284{
Martin Schwidefskyd66bf802017-08-21 14:47:04 +0200285 if (copy_with_mvcos())
Heiko Carstens457f2182014-03-21 10:42:25 +0100286 return clear_user_mvcos(to, size);
287 return clear_user_xc(to, size);
288}
289EXPORT_SYMBOL(__clear_user);