xref: /OK3568_Linux_fs/kernel/arch/s390/lib/mem.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun/*
3*4882a593Smuzhiyun * String handling functions.
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright IBM Corp. 2012
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun#include <linux/linkage.h>
9*4882a593Smuzhiyun#include <asm/export.h>
10*4882a593Smuzhiyun#include <asm/nospec-insn.h>
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun	GEN_BR_THUNK %r14
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun/*
15*4882a593Smuzhiyun * void *memmove(void *dest, const void *src, size_t n)
16*4882a593Smuzhiyun */
17*4882a593SmuzhiyunWEAK(memmove)
18*4882a593SmuzhiyunENTRY(__memmove)
19*4882a593Smuzhiyun	ltgr	%r4,%r4
20*4882a593Smuzhiyun	lgr	%r1,%r2
21*4882a593Smuzhiyun	jz	.Lmemmove_exit
22*4882a593Smuzhiyun	aghi	%r4,-1
23*4882a593Smuzhiyun	clgr	%r2,%r3
24*4882a593Smuzhiyun	jnh	.Lmemmove_forward
25*4882a593Smuzhiyun	la	%r5,1(%r4,%r3)
26*4882a593Smuzhiyun	clgr	%r2,%r5
27*4882a593Smuzhiyun	jl	.Lmemmove_reverse
28*4882a593Smuzhiyun.Lmemmove_forward:
29*4882a593Smuzhiyun	srlg	%r0,%r4,8
30*4882a593Smuzhiyun	ltgr	%r0,%r0
31*4882a593Smuzhiyun	jz	.Lmemmove_forward_remainder
32*4882a593Smuzhiyun.Lmemmove_forward_loop:
33*4882a593Smuzhiyun	mvc	0(256,%r1),0(%r3)
34*4882a593Smuzhiyun	la	%r1,256(%r1)
35*4882a593Smuzhiyun	la	%r3,256(%r3)
36*4882a593Smuzhiyun	brctg	%r0,.Lmemmove_forward_loop
37*4882a593Smuzhiyun.Lmemmove_forward_remainder:
38*4882a593Smuzhiyun	larl	%r5,.Lmemmove_mvc
39*4882a593Smuzhiyun	ex	%r4,0(%r5)
40*4882a593Smuzhiyun.Lmemmove_exit:
41*4882a593Smuzhiyun	BR_EX	%r14
42*4882a593Smuzhiyun.Lmemmove_reverse:
43*4882a593Smuzhiyun	ic	%r0,0(%r4,%r3)
44*4882a593Smuzhiyun	stc	%r0,0(%r4,%r1)
45*4882a593Smuzhiyun	brctg	%r4,.Lmemmove_reverse
46*4882a593Smuzhiyun	ic	%r0,0(%r4,%r3)
47*4882a593Smuzhiyun	stc	%r0,0(%r4,%r1)
48*4882a593Smuzhiyun	BR_EX	%r14
49*4882a593Smuzhiyun.Lmemmove_mvc:
50*4882a593Smuzhiyun	mvc	0(1,%r1),0(%r3)
51*4882a593SmuzhiyunENDPROC(__memmove)
52*4882a593SmuzhiyunEXPORT_SYMBOL(memmove)
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun/*
55*4882a593Smuzhiyun * memset implementation
56*4882a593Smuzhiyun *
57*4882a593Smuzhiyun * This code corresponds to the C construct below. We do distinguish
58*4882a593Smuzhiyun * between clearing (c == 0) and setting a memory array (c != 0) simply
59*4882a593Smuzhiyun * because nearly all memset invocations in the kernel clear memory and
60*4882a593Smuzhiyun * the xc instruction is preferred in such cases.
61*4882a593Smuzhiyun *
62*4882a593Smuzhiyun * void *memset(void *s, int c, size_t n)
63*4882a593Smuzhiyun * {
64*4882a593Smuzhiyun *	if (likely(c == 0))
65*4882a593Smuzhiyun *		return __builtin_memset(s, 0, n);
66*4882a593Smuzhiyun *	return __builtin_memset(s, c, n);
67*4882a593Smuzhiyun * }
68*4882a593Smuzhiyun */
69*4882a593SmuzhiyunWEAK(memset)
70*4882a593SmuzhiyunENTRY(__memset)
71*4882a593Smuzhiyun	ltgr	%r4,%r4
72*4882a593Smuzhiyun	jz	.Lmemset_exit
73*4882a593Smuzhiyun	ltgr	%r3,%r3
74*4882a593Smuzhiyun	jnz	.Lmemset_fill
75*4882a593Smuzhiyun	aghi	%r4,-1
76*4882a593Smuzhiyun	srlg	%r3,%r4,8
77*4882a593Smuzhiyun	ltgr	%r3,%r3
78*4882a593Smuzhiyun	lgr	%r1,%r2
79*4882a593Smuzhiyun	jz	.Lmemset_clear_remainder
80*4882a593Smuzhiyun.Lmemset_clear_loop:
81*4882a593Smuzhiyun	xc	0(256,%r1),0(%r1)
82*4882a593Smuzhiyun	la	%r1,256(%r1)
83*4882a593Smuzhiyun	brctg	%r3,.Lmemset_clear_loop
84*4882a593Smuzhiyun.Lmemset_clear_remainder:
85*4882a593Smuzhiyun	larl	%r3,.Lmemset_xc
86*4882a593Smuzhiyun	ex	%r4,0(%r3)
87*4882a593Smuzhiyun.Lmemset_exit:
88*4882a593Smuzhiyun	BR_EX	%r14
89*4882a593Smuzhiyun.Lmemset_fill:
90*4882a593Smuzhiyun	cghi	%r4,1
91*4882a593Smuzhiyun	lgr	%r1,%r2
92*4882a593Smuzhiyun	je	.Lmemset_fill_exit
93*4882a593Smuzhiyun	aghi	%r4,-2
94*4882a593Smuzhiyun	srlg	%r5,%r4,8
95*4882a593Smuzhiyun	ltgr	%r5,%r5
96*4882a593Smuzhiyun	jz	.Lmemset_fill_remainder
97*4882a593Smuzhiyun.Lmemset_fill_loop:
98*4882a593Smuzhiyun	stc	%r3,0(%r1)
99*4882a593Smuzhiyun	mvc	1(255,%r1),0(%r1)
100*4882a593Smuzhiyun	la	%r1,256(%r1)
101*4882a593Smuzhiyun	brctg	%r5,.Lmemset_fill_loop
102*4882a593Smuzhiyun.Lmemset_fill_remainder:
103*4882a593Smuzhiyun	stc	%r3,0(%r1)
104*4882a593Smuzhiyun	larl	%r5,.Lmemset_mvc
105*4882a593Smuzhiyun	ex	%r4,0(%r5)
106*4882a593Smuzhiyun	BR_EX	%r14
107*4882a593Smuzhiyun.Lmemset_fill_exit:
108*4882a593Smuzhiyun	stc	%r3,0(%r1)
109*4882a593Smuzhiyun	BR_EX	%r14
110*4882a593Smuzhiyun.Lmemset_xc:
111*4882a593Smuzhiyun	xc	0(1,%r1),0(%r1)
112*4882a593Smuzhiyun.Lmemset_mvc:
113*4882a593Smuzhiyun	mvc	1(1,%r1),0(%r1)
114*4882a593SmuzhiyunENDPROC(__memset)
115*4882a593SmuzhiyunEXPORT_SYMBOL(memset)
116*4882a593Smuzhiyun
117*4882a593Smuzhiyun/*
118*4882a593Smuzhiyun * memcpy implementation
119*4882a593Smuzhiyun *
120*4882a593Smuzhiyun * void *memcpy(void *dest, const void *src, size_t n)
121*4882a593Smuzhiyun */
122*4882a593SmuzhiyunWEAK(memcpy)
123*4882a593SmuzhiyunENTRY(__memcpy)
124*4882a593Smuzhiyun	ltgr	%r4,%r4
125*4882a593Smuzhiyun	jz	.Lmemcpy_exit
126*4882a593Smuzhiyun	aghi	%r4,-1
127*4882a593Smuzhiyun	srlg	%r5,%r4,8
128*4882a593Smuzhiyun	ltgr	%r5,%r5
129*4882a593Smuzhiyun	lgr	%r1,%r2
130*4882a593Smuzhiyun	jnz	.Lmemcpy_loop
131*4882a593Smuzhiyun.Lmemcpy_remainder:
132*4882a593Smuzhiyun	larl	%r5,.Lmemcpy_mvc
133*4882a593Smuzhiyun	ex	%r4,0(%r5)
134*4882a593Smuzhiyun.Lmemcpy_exit:
135*4882a593Smuzhiyun	BR_EX	%r14
136*4882a593Smuzhiyun.Lmemcpy_loop:
137*4882a593Smuzhiyun	mvc	0(256,%r1),0(%r3)
138*4882a593Smuzhiyun	la	%r1,256(%r1)
139*4882a593Smuzhiyun	la	%r3,256(%r3)
140*4882a593Smuzhiyun	brctg	%r5,.Lmemcpy_loop
141*4882a593Smuzhiyun	j	.Lmemcpy_remainder
142*4882a593Smuzhiyun.Lmemcpy_mvc:
143*4882a593Smuzhiyun	mvc	0(1,%r1),0(%r3)
144*4882a593SmuzhiyunENDPROC(__memcpy)
145*4882a593SmuzhiyunEXPORT_SYMBOL(memcpy)
146*4882a593Smuzhiyun
147*4882a593Smuzhiyun/*
148*4882a593Smuzhiyun * __memset16/32/64
149*4882a593Smuzhiyun *
150*4882a593Smuzhiyun * void *__memset16(uint16_t *s, uint16_t v, size_t count)
151*4882a593Smuzhiyun * void *__memset32(uint32_t *s, uint32_t v, size_t count)
152*4882a593Smuzhiyun * void *__memset64(uint64_t *s, uint64_t v, size_t count)
153*4882a593Smuzhiyun */
154*4882a593Smuzhiyun.macro __MEMSET bits,bytes,insn
155*4882a593SmuzhiyunENTRY(__memset\bits)
156*4882a593Smuzhiyun	ltgr	%r4,%r4
157*4882a593Smuzhiyun	jz	.L__memset_exit\bits
158*4882a593Smuzhiyun	cghi	%r4,\bytes
159*4882a593Smuzhiyun	je	.L__memset_store\bits
160*4882a593Smuzhiyun	aghi	%r4,-(\bytes+1)
161*4882a593Smuzhiyun	srlg	%r5,%r4,8
162*4882a593Smuzhiyun	ltgr	%r5,%r5
163*4882a593Smuzhiyun	lgr	%r1,%r2
164*4882a593Smuzhiyun	jz	.L__memset_remainder\bits
165*4882a593Smuzhiyun.L__memset_loop\bits:
166*4882a593Smuzhiyun	\insn	%r3,0(%r1)
167*4882a593Smuzhiyun	mvc	\bytes(256-\bytes,%r1),0(%r1)
168*4882a593Smuzhiyun	la	%r1,256(%r1)
169*4882a593Smuzhiyun	brctg	%r5,.L__memset_loop\bits
170*4882a593Smuzhiyun.L__memset_remainder\bits:
171*4882a593Smuzhiyun	\insn	%r3,0(%r1)
172*4882a593Smuzhiyun	larl	%r5,.L__memset_mvc\bits
173*4882a593Smuzhiyun	ex	%r4,0(%r5)
174*4882a593Smuzhiyun	BR_EX	%r14
175*4882a593Smuzhiyun.L__memset_store\bits:
176*4882a593Smuzhiyun	\insn	%r3,0(%r2)
177*4882a593Smuzhiyun.L__memset_exit\bits:
178*4882a593Smuzhiyun	BR_EX	%r14
179*4882a593Smuzhiyun.L__memset_mvc\bits:
180*4882a593Smuzhiyun	mvc	\bytes(1,%r1),0(%r1)
181*4882a593SmuzhiyunENDPROC(__memset\bits)
182*4882a593Smuzhiyun.endm
183*4882a593Smuzhiyun
184*4882a593Smuzhiyun__MEMSET 16,2,sth
185*4882a593SmuzhiyunEXPORT_SYMBOL(__memset16)
186*4882a593Smuzhiyun
187*4882a593Smuzhiyun__MEMSET 32,4,st
188*4882a593SmuzhiyunEXPORT_SYMBOL(__memset32)
189*4882a593Smuzhiyun
190*4882a593Smuzhiyun__MEMSET 64,8,stg
191*4882a593SmuzhiyunEXPORT_SYMBOL(__memset64)
192