1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/*
 
 
 
 
 
 
 
 
 
 
 
 
 
  3 *
  4 * Copyright (C) IBM Corporation, 2012
  5 *
  6 * Author: Anton Blanchard <anton@au.ibm.com>
  7 */
  8
  9#include <linux/export.h>
 10#include <asm/ppc_asm.h>
 11#include <asm/linkage.h>
 12#include <asm/asm-offsets.h>
 
 
 
 
 
 
 13
 14/**
 15 * __arch_clear_user: - Zero a block of memory in user space, with less checking.
 16 * @to:   Destination address, in user space.
 17 * @n:    Number of bytes to zero.
 18 *
 19 * Zero a block of memory in user space.  Caller must check
 20 * the specified block with access_ok() before calling this function.
 21 *
 22 * Returns number of bytes that could not be cleared.
 23 * On success, this will be zero.
 24 */
 25
 26	.macro err1
 27100:
 28	EX_TABLE(100b,.Ldo_err1)
 29	.endm
 30
 31	.macro err2
 32200:
 33	EX_TABLE(200b,.Ldo_err2)
 34	.endm
 35
 36	.macro err3
 37300:
 38	EX_TABLE(300b,.Ldo_err3)
 39	.endm
 40
 41.Ldo_err1:
 42	mr	r3,r8
 43
 44.Ldo_err2:
 45	mtctr	r4
 461:
 47err3;	stb	r0,0(r3)
 48	addi	r3,r3,1
 49	addi	r4,r4,-1
 50	bdnz	1b
 51
 52.Ldo_err3:
 53	mr	r3,r4
 54	blr
 55
 56_GLOBAL_TOC(__arch_clear_user)
 57	cmpdi	r4,32
 58	neg	r6,r3
 59	li	r0,0
 60	blt	.Lshort_clear
 61	mr	r8,r3
 62	mtocrf	0x01,r6
 63	clrldi	r6,r6,(64-3)
 64
 65	/* Get the destination 8 byte aligned */
 66	bf	cr7*4+3,1f
 67err1;	stb	r0,0(r3)
 68	addi	r3,r3,1
 69
 701:	bf	cr7*4+2,2f
 71err1;	sth	r0,0(r3)
 72	addi	r3,r3,2
 73
 742:	bf	cr7*4+1,3f
 75err1;	stw	r0,0(r3)
 76	addi	r3,r3,4
 77
 783:	sub	r4,r4,r6
 79
 80	cmpdi	r4,32
 81	cmpdi	cr1,r4,512
 82	blt	.Lshort_clear
 83	bgt	cr1,.Llong_clear
 84
 85.Lmedium_clear:
 86	srdi	r6,r4,5
 87	mtctr	r6
 88
 89	/* Do 32 byte chunks */
 904:
 91err2;	std	r0,0(r3)
 92err2;	std	r0,8(r3)
 93err2;	std	r0,16(r3)
 94err2;	std	r0,24(r3)
 95	addi	r3,r3,32
 96	addi	r4,r4,-32
 97	bdnz	4b
 98
 99.Lshort_clear:
100	/* up to 31 bytes to go */
101	cmpdi	r4,16
102	blt	6f
103err2;	std	r0,0(r3)
104err2;	std	r0,8(r3)
105	addi	r3,r3,16
106	addi	r4,r4,-16
107
108	/* Up to 15 bytes to go */
1096:	mr	r8,r3
110	clrldi	r4,r4,(64-4)
111	mtocrf	0x01,r4
112	bf	cr7*4+0,7f
113err1;	std	r0,0(r3)
114	addi	r3,r3,8
115
1167:	bf	cr7*4+1,8f
117err1;	stw	r0,0(r3)
118	addi	r3,r3,4
119
1208:	bf	cr7*4+2,9f
121err1;	sth	r0,0(r3)
122	addi	r3,r3,2
123
1249:	bf	cr7*4+3,10f
125err1;	stb	r0,0(r3)
126
12710:	li	r3,0
128	blr
129
130.Llong_clear:
131	LOAD_REG_ADDR(r5, ppc64_caches)
132
133	bf	cr7*4+0,11f
134err2;	std	r0,0(r3)
135	addi	r3,r3,8
136	addi	r4,r4,-8
137
138	/* Destination is 16 byte aligned, need to get it cache block aligned */
13911:	lwz	r7,DCACHEL1LOGBLOCKSIZE(r5)
140	lwz	r9,DCACHEL1BLOCKSIZE(r5)
141
142	/*
143	 * With worst case alignment the long clear loop takes a minimum
144	 * of 1 byte less than 2 cachelines.
145	 */
146	sldi	r10,r9,2
147	cmpd	r4,r10
148	blt	.Lmedium_clear
149
150	neg	r6,r3
151	addi	r10,r9,-1
152	and.	r5,r6,r10
153	beq	13f
154
155	srdi	r6,r5,4
156	mtctr	r6
157	mr	r8,r3
15812:
159err1;	std	r0,0(r3)
160err1;	std	r0,8(r3)
161	addi	r3,r3,16
162	bdnz	12b
163
164	sub	r4,r4,r5
165
16613:	srd	r6,r4,r7
167	mtctr	r6
168	mr	r8,r3
16914:
170err1;	dcbz	0,r3
171	add	r3,r3,r9
172	bdnz	14b
173
174	and	r4,r4,r10
175
176	cmpdi	r4,32
177	blt	.Lshort_clear
178	b	.Lmedium_clear
179EXPORT_SYMBOL(__arch_clear_user)

 
  1/*
  2 * This program is free software; you can redistribute it and/or modify
  3 * it under the terms of the GNU General Public License as published by
  4 * the Free Software Foundation; either version 2 of the License, or
  5 * (at your option) any later version.
  6 *
  7 * This program is distributed in the hope that it will be useful,
  8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 10 * GNU General Public License for more details.
 11 *
 12 * You should have received a copy of the GNU General Public License
 13 * along with this program; if not, write to the Free Software
 14 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 15 *
 16 * Copyright (C) IBM Corporation, 2012
 17 *
 18 * Author: Anton Blanchard <anton@au.ibm.com>
 19 */
 20
 
 21#include <asm/ppc_asm.h>
 22#include <asm/linkage.h>
 23#include <asm/asm-offsets.h>
 24#include <asm/export.h>
 25
 26	.section	".toc","aw"
 27PPC64_CACHES:
 28	.tc		ppc64_caches[TC],ppc64_caches
 29	.section	".text"
 30
 31/**
 32 * __clear_user: - Zero a block of memory in user space, with less checking.
 33 * @to:   Destination address, in user space.
 34 * @n:    Number of bytes to zero.
 35 *
 36 * Zero a block of memory in user space.  Caller must check
 37 * the specified block with access_ok() before calling this function.
 38 *
 39 * Returns number of bytes that could not be cleared.
 40 * On success, this will be zero.
 41 */
 42
 43	.macro err1
 44100:
 45	EX_TABLE(100b,.Ldo_err1)
 46	.endm
 47
 48	.macro err2
 49200:
 50	EX_TABLE(200b,.Ldo_err2)
 51	.endm
 52
 53	.macro err3
 54300:
 55	EX_TABLE(300b,.Ldo_err3)
 56	.endm
 57
 58.Ldo_err1:
 59	mr	r3,r8
 60
 61.Ldo_err2:
 62	mtctr	r4
 631:
 64err3;	stb	r0,0(r3)
 65	addi	r3,r3,1
 66	addi	r4,r4,-1
 67	bdnz	1b
 68
 69.Ldo_err3:
 70	mr	r3,r4
 71	blr
 72
 73_GLOBAL_TOC(__clear_user)
 74	cmpdi	r4,32
 75	neg	r6,r3
 76	li	r0,0
 77	blt	.Lshort_clear
 78	mr	r8,r3
 79	mtocrf	0x01,r6
 80	clrldi	r6,r6,(64-3)
 81
 82	/* Get the destination 8 byte aligned */
 83	bf	cr7*4+3,1f
 84err1;	stb	r0,0(r3)
 85	addi	r3,r3,1
 86
 871:	bf	cr7*4+2,2f
 88err1;	sth	r0,0(r3)
 89	addi	r3,r3,2
 90
 912:	bf	cr7*4+1,3f
 92err1;	stw	r0,0(r3)
 93	addi	r3,r3,4
 94
 953:	sub	r4,r4,r6
 96
 97	cmpdi	r4,32
 98	cmpdi	cr1,r4,512
 99	blt	.Lshort_clear
100	bgt	cr1,.Llong_clear
101
102.Lmedium_clear:
103	srdi	r6,r4,5
104	mtctr	r6
105
106	/* Do 32 byte chunks */
1074:
108err2;	std	r0,0(r3)
109err2;	std	r0,8(r3)
110err2;	std	r0,16(r3)
111err2;	std	r0,24(r3)
112	addi	r3,r3,32
113	addi	r4,r4,-32
114	bdnz	4b
115
116.Lshort_clear:
117	/* up to 31 bytes to go */
118	cmpdi	r4,16
119	blt	6f
120err2;	std	r0,0(r3)
121err2;	std	r0,8(r3)
122	addi	r3,r3,16
123	addi	r4,r4,-16
124
125	/* Up to 15 bytes to go */
1266:	mr	r8,r3
127	clrldi	r4,r4,(64-4)
128	mtocrf	0x01,r4
129	bf	cr7*4+0,7f
130err1;	std	r0,0(r3)
131	addi	r3,r3,8
132
1337:	bf	cr7*4+1,8f
134err1;	stw	r0,0(r3)
135	addi	r3,r3,4
136
1378:	bf	cr7*4+2,9f
138err1;	sth	r0,0(r3)
139	addi	r3,r3,2
140
1419:	bf	cr7*4+3,10f
142err1;	stb	r0,0(r3)
143
14410:	li	r3,0
145	blr
146
147.Llong_clear:
148	ld	r5,PPC64_CACHES@toc(r2)
149
150	bf	cr7*4+0,11f
151err2;	std	r0,0(r3)
152	addi	r3,r3,8
153	addi	r4,r4,-8
154
155	/* Destination is 16 byte aligned, need to get it cache block aligned */
15611:	lwz	r7,DCACHEL1LOGBLOCKSIZE(r5)
157	lwz	r9,DCACHEL1BLOCKSIZE(r5)
158
159	/*
160	 * With worst case alignment the long clear loop takes a minimum
161	 * of 1 byte less than 2 cachelines.
162	 */
163	sldi	r10,r9,2
164	cmpd	r4,r10
165	blt	.Lmedium_clear
166
167	neg	r6,r3
168	addi	r10,r9,-1
169	and.	r5,r6,r10
170	beq	13f
171
172	srdi	r6,r5,4
173	mtctr	r6
174	mr	r8,r3
17512:
176err1;	std	r0,0(r3)
177err1;	std	r0,8(r3)
178	addi	r3,r3,16
179	bdnz	12b
180
181	sub	r4,r4,r5
182
18313:	srd	r6,r4,r7
184	mtctr	r6
185	mr	r8,r3
18614:
187err1;	dcbz	0,r3
188	add	r3,r3,r9
189	bdnz	14b
190
191	and	r4,r4,r10
192
193	cmpdi	r4,32
194	blt	.Lshort_clear
195	b	.Lmedium_clear
196EXPORT_SYMBOL(__clear_user)