1 // SPDX-License-Identifier: GPL-2.0
3 * Standard user space access functions based on mvcp/mvcs and doing
4 * interesting things in the secondary space mode.
6 * Copyright IBM Corp. 2006,2014
7 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
8 * Gerald Schaefer (gerald.schaefer@de.ibm.com)
11 #include <linux/uaccess.h>
12 #include <linux/export.h>
14 #include <asm/asm-extable.h>
15 #include <asm/ctlreg.h>
17 #ifdef CONFIG_DEBUG_ENTRY
18 void debug_user_asce(int exit)
20 struct ctlreg cr1, cr7;
22 local_ctl_store(1, &cr1);
23 local_ctl_store(7, &cr7);
24 if (cr1.val == S390_lowcore.kernel_asce.val && cr7.val == S390_lowcore.user_asce.val)
26 panic("incorrect ASCE on kernel %s\n"
27 "cr1: %016lx cr7: %016lx\n"
28 "kernel: %016lx user: %016lx\n",
29 exit ? "exit" : "entry", cr1.val, cr7.val,
30 S390_lowcore.kernel_asce.val, S390_lowcore.user_asce.val);
32 #endif /*CONFIG_DEBUG_ENTRY */
34 static unsigned long raw_copy_from_user_key(void *to, const void __user *from,
35 unsigned long size, unsigned long key)
40 .oac2.as = PSW_BITS_AS_SECONDARY,
47 "0: mvcos 0(%[to]),0(%[from]),%[size]\n"
49 " algr %[size],%[val]\n"
50 " slgr %[from],%[val]\n"
51 " slgr %[to],%[val]\n"
53 "2: la %[rem],4095(%[from])\n" /* rem = from + 4095 */
54 " nr %[rem],%[val]\n" /* rem = (from + 4095) & -4096 */
55 " slgr %[rem],%[from]\n"
56 " clgr %[size],%[rem]\n" /* copy crosses next page boundary? */
58 "3: mvcos 0(%[to]),0(%[from]),%[rem]\n"
59 "4: slgr %[size],%[rem]\n"
61 "5: slgr %[size],%[size]\n"
67 : [size] "+&a" (size), [from] "+&a" (from), [to] "+&a" (to), [rem] "=&a" (rem)
68 : [val] "a" (-4096UL), [spec] "d" (spec.val)
69 : "cc", "memory", "0");
73 unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
75 return raw_copy_from_user_key(to, from, n, 0);
77 EXPORT_SYMBOL(raw_copy_from_user);
79 unsigned long _copy_from_user_key(void *to, const void __user *from,
80 unsigned long n, unsigned long key)
82 unsigned long res = n;
85 if (!should_fail_usercopy()) {
86 instrument_copy_from_user_before(to, from, n);
87 res = raw_copy_from_user_key(to, from, n, key);
88 instrument_copy_from_user_after(to, from, n, res);
91 memset(to + (n - res), 0, res);
94 EXPORT_SYMBOL(_copy_from_user_key);
96 static unsigned long raw_copy_to_user_key(void __user *to, const void *from,
97 unsigned long size, unsigned long key)
102 .oac1.as = PSW_BITS_AS_SECONDARY,
109 "0: mvcos 0(%[to]),0(%[from]),%[size]\n"
111 " algr %[size],%[val]\n"
112 " slgr %[to],%[val]\n"
113 " slgr %[from],%[val]\n"
115 "2: la %[rem],4095(%[to])\n" /* rem = to + 4095 */
116 " nr %[rem],%[val]\n" /* rem = (to + 4095) & -4096 */
117 " slgr %[rem],%[to]\n"
118 " clgr %[size],%[rem]\n" /* copy crosses next page boundary? */
120 "3: mvcos 0(%[to]),0(%[from]),%[rem]\n"
121 "4: slgr %[size],%[rem]\n"
123 "5: slgr %[size],%[size]\n"
129 : [size] "+&a" (size), [to] "+&a" (to), [from] "+&a" (from), [rem] "=&a" (rem)
130 : [val] "a" (-4096UL), [spec] "d" (spec.val)
131 : "cc", "memory", "0");
135 unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
137 return raw_copy_to_user_key(to, from, n, 0);
139 EXPORT_SYMBOL(raw_copy_to_user);
141 unsigned long _copy_to_user_key(void __user *to, const void *from,
142 unsigned long n, unsigned long key)
145 if (should_fail_usercopy())
147 instrument_copy_to_user(to, from, n);
148 return raw_copy_to_user_key(to, from, n, key);
150 EXPORT_SYMBOL(_copy_to_user_key);
152 unsigned long __clear_user(void __user *to, unsigned long size)
156 .oac1.as = PSW_BITS_AS_SECONDARY,
162 "0: mvcos 0(%[to]),0(%[zeropg]),%[size]\n"
164 " algr %[size],%[val]\n"
165 " slgr %[to],%[val]\n"
167 "2: la %[rem],4095(%[to])\n" /* rem = to + 4095 */
168 " nr %[rem],%[val]\n" /* rem = (to + 4095) & -4096 */
169 " slgr %[rem],%[to]\n"
170 " clgr %[size],%[rem]\n" /* copy crosses next page boundary? */
172 "3: mvcos 0(%[to]),0(%[zeropg]),%[rem]\n"
173 "4: slgr %[size],%[rem]\n"
175 "5: slgr %[size],%[size]\n"
181 : [size] "+&a" (size), [to] "+&a" (to), [rem] "=&a" (rem)
182 : [val] "a" (-4096UL), [zeropg] "a" (empty_zero_page), [spec] "d" (spec.val)
183 : "cc", "memory", "0");
186 EXPORT_SYMBOL(__clear_user);