summaryrefslogtreecommitdiffstats
path: root/arch/s390/lib/uaccess_mvcos.c
blob: 58a75a8ae90ce7beae1a4553801c47dd544cd1ee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
/*
 *  arch/s390/lib/uaccess_mvcos.c
 *
 *  Optimized user space space access functions based on mvcos.
 *
 *    Copyright (C) IBM Corp. 2006
 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
 *		 Gerald Schaefer (gerald.schaefer@de.ibm.com)
 */

#include <linux/errno.h>
#include <linux/mm.h>
#include <asm/uaccess.h>
#include <asm/futex.h>
#include "uaccess.h"

#ifndef CONFIG_64BIT
#define AHI	"ahi"
#define ALR	"alr"
#define CLR	"clr"
#define LHI	"lhi"
#define SLR	"slr"
#else
#define AHI	"aghi"
#define ALR	"algr"
#define CLR	"clgr"
#define LHI	"lghi"
#define SLR	"slgr"
#endif

static size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x)
{
	register unsigned long reg0 asm("0") = 0x81UL;
	unsigned long tmp1, tmp2;

	tmp1 = -4096UL;
	asm volatile(
		"0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
		"9: jz    7f\n"
		"1:"ALR"  %0,%3\n"
		"  "SLR"  %1,%3\n"
		"  "SLR"  %2,%3\n"
		"   j     0b\n"
		"2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
		"   nr    %4,%3\n"	/* %4 = (ptr + 4095) & -4096 */
		"  "SLR"  %4,%1\n"
		"  "CLR"  %0,%4\n"	/* copy crosses next page boundary? */
		"   jnh   4f\n"
		"3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
		"10:"SLR"  %0,%4\n"
		"  "ALR"  %2,%4\n"
		"4:"LHI"  %4,-1\n"
		"  "ALR"  %4,%0\n"	/* copy remaining size, subtract 1 */
		"   bras  %3,6f\n"	/* memset loop */
		"   xc    0(1,%2),0(%2)\n"
		"5: xc    0(256,%2),0(%2)\n"
		"   la    %2,256(%2)\n"
		"6:"AHI"  %4,-256\n"
		"   jnm   5b\n"
		"   ex    %4,0(%3)\n"
		"   j     8f\n"
		"7:"SLR"  %0,%0\n"
		"8: \n"
		EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
		: "d" (reg0) : "cc", "memory");
	return size;
}

static size_t copy_from_user_mvcos_check(size_t size, const void __user *ptr, void *x)
{
	if (size <= 256)
		return copy_from_user_std(size, ptr, x);
	return copy_from_user_mvcos(size, ptr, x);
}

static size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x)
{
	register unsigned long reg0 asm("0") = 0x810000UL;
	unsigned long tmp1, tmp2;

	tmp1 = -4096UL;
	asm volatile(
		"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
		"6: jz    4f\n"
		"1:"ALR"  %0,%3\n"
		"  "SLR"  %1,%3\n"
		"  "SLR"  %2,%3\n"
		"   j     0b\n"
		"2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
		"   nr    %4,%3\n"	/* %4 = (ptr + 4095) & -4096 */
		"  "SLR"  %4,%1\n"
		"  "CLR"  %0,%4\n"	/* copy crosses next page boundary? */
		"   jnh   5f\n"
		"3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
		"7:"SLR"  %0,%4\n"
		"   j     5f\n"
		"4:"SLR"  %0,%0\n"
		"5: \n"
		EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
		: "d" (reg0) : "cc", "memory");
	return size;
}

static size_t copy_to_user_mvcos_check(size_t size, void __user *ptr,
				       const void *x)
{
	if (size <= 256)
		return copy_to_user_std(size, ptr, x);
	return copy_to_user_mvcos(size, ptr, x);
}

static size_t copy_in_user_mvcos(size_t size, void __user *to,
				 const void __user *from)
{
	register unsigned long reg0 asm("0") = 0x810081UL;
	unsigned long tmp1, tmp2;

	tmp1 = -4096UL;
	/* FIXME: copy with reduced length. */
	asm volatile(
		"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
		"   jz    2f\n"
		"1:"ALR"  %0,%3\n"
		"  "SLR"  %1,%3\n"
		"  "SLR"  %2,%3\n"
		"   j     0b\n"
		"2:"SLR"  %0,%0\n"
		"3: \n"
		EX_TABLE(0b,3b)
		: "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
		: "d" (reg0) : "cc", "memory");
	return size;
}

static size_t clear_user_mvcos(size_t size, void __user *to)
{
	register unsigned long reg0 asm("0") = 0x810000UL;
	unsigned long tmp1, tmp2;

	tmp1 = -4096UL;
	asm volatile(
		"0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
		"   jz    4f\n"
		"1:"ALR"  %0,%2\n"
		"  "SLR"  %1,%2\n"
		"   j     0b\n"
		"2: la    %3,4095(%1)\n"/* %4 = to + 4095 */
		"   nr    %3,%2\n"	/* %4 = (to + 4095) & -4096 */
		"  "SLR"  %3,%1\n"
		"  "CLR"  %0,%3\n"	/* copy crosses next page boundary? */
		"   jnh   5f\n"
		"3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
		"  "SLR"  %0,%3\n"
		"   j     5f\n"
		"4:"SLR"  %0,%0\n"
		"5: \n"
		EX_TABLE(0b,2b) EX_TABLE(3b,5b)
		: "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
		: "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
	return size;
}

static size_t strnlen_user_mvcos(size_t count, const char __user *src)
{
	char buf[256];
	int rc;
	size_t done, len, len_str;

	done = 0;
	do {
		len = min(count - done, (size_t) 256);
		rc = uaccess.copy_from_user(len, src + done, buf);
		if (unlikely(rc == len))
			return 0;
		len -= rc;
		len_str = strnlen(buf, len);
		done += len_str;
	} while ((len_str == len) && (done < count));
	return done + 1;
}

static size_t strncpy_from_user_mvcos(size_t count, const char __user *src,
				      char *dst)
{
	int rc;
	size_t done, len, len_str;

	done = 0;
	do {
		len = min(count - done, (size_t) 4096);
		rc = uaccess.copy_from_user(len, src + done, dst);
		if (unlikely(rc == len))
			return -EFAULT;
		len -= rc;
		len_str = strnlen(dst, len);
		done += len_str;
	} while ((len_str == len) && (done < count));
	return done;
}

struct uaccess_ops uaccess_mvcos = {
	.copy_from_user = copy_from_user_mvcos_check,
	.copy_from_user_small = copy_from_user_std,
	.copy_to_user = copy_to_user_mvcos_check,
	.copy_to_user_small = copy_to_user_std,
	.copy_in_user = copy_in_user_mvcos,
	.clear_user = clear_user_mvcos,
	.strnlen_user = strnlen_user_std,
	.strncpy_from_user = strncpy_from_user_std,
	.futex_atomic_op = futex_atomic_op_std,
	.futex_atomic_cmpxchg = futex_atomic_cmpxchg_std,
};

struct uaccess_ops uaccess_mvcos_switch = {
	.copy_from_user = copy_from_user_mvcos,
	.copy_from_user_small = copy_from_user_mvcos,
	.copy_to_user = copy_to_user_mvcos,
	.copy_to_user_small = copy_to_user_mvcos,
	.copy_in_user = copy_in_user_mvcos,
	.clear_user = clear_user_mvcos,
	.strnlen_user = strnlen_user_mvcos,
	.strncpy_from_user = strncpy_from_user_mvcos,
	.futex_atomic_op = futex_atomic_op_pt,
	.futex_atomic_cmpxchg = futex_atomic_cmpxchg_pt,
};
OpenPOWER on IntegriCloud