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/* 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 <asm/ppc_asm.h>
 10#include <asm/linkage.h>
 11#include <asm/asm-offsets.h>
 12#include <asm/export.h>
 13
 14	.section	".toc","aw"
 15PPC64_CACHES:
 16	.tc		ppc64_caches[TC],ppc64_caches
 17	.section	".text"
 18
 19/**
 20 * __arch_clear_user: - Zero a block of memory in user space, with less checking.
 21 * @to:   Destination address, in user space.
 22 * @n:    Number of bytes to zero.
 23 *
 24 * Zero a block of memory in user space.  Caller must check
 25 * the specified block with access_ok() before calling this function.
 26 *
 27 * Returns number of bytes that could not be cleared.
 28 * On success, this will be zero.
 29 */
 30
 31	.macro err1
 32100:
 33	EX_TABLE(100b,.Ldo_err1)
 34	.endm
 35
 36	.macro err2
 37200:
 38	EX_TABLE(200b,.Ldo_err2)
 39	.endm
 40
 41	.macro err3
 42300:
 43	EX_TABLE(300b,.Ldo_err3)
 44	.endm
 45
 46.Ldo_err1:
 47	mr	r3,r8
 48
 49.Ldo_err2:
 50	mtctr	r4
 511:
 52err3;	stb	r0,0(r3)
 53	addi	r3,r3,1
 54	addi	r4,r4,-1
 55	bdnz	1b
 56
 57.Ldo_err3:
 58	mr	r3,r4
 59	blr
 60
 61_GLOBAL_TOC(__arch_clear_user)
 62	cmpdi	r4,32
 63	neg	r6,r3
 64	li	r0,0
 65	blt	.Lshort_clear
 66	mr	r8,r3
 67	mtocrf	0x01,r6
 68	clrldi	r6,r6,(64-3)
 69
 70	/* Get the destination 8 byte aligned */
 71	bf	cr7*4+3,1f
 72err1;	stb	r0,0(r3)
 73	addi	r3,r3,1
 74
 751:	bf	cr7*4+2,2f
 76err1;	sth	r0,0(r3)
 77	addi	r3,r3,2
 78
 792:	bf	cr7*4+1,3f
 80err1;	stw	r0,0(r3)
 81	addi	r3,r3,4
 82
 833:	sub	r4,r4,r6
 84
 85	cmpdi	r4,32
 86	cmpdi	cr1,r4,512
 87	blt	.Lshort_clear
 88	bgt	cr1,.Llong_clear
 89
 90.Lmedium_clear:
 91	srdi	r6,r4,5
 92	mtctr	r6
 93
 94	/* Do 32 byte chunks */
 954:
 96err2;	std	r0,0(r3)
 97err2;	std	r0,8(r3)
 98err2;	std	r0,16(r3)
 99err2;	std	r0,24(r3)
100	addi	r3,r3,32
101	addi	r4,r4,-32
102	bdnz	4b
103
104.Lshort_clear:
105	/* up to 31 bytes to go */
106	cmpdi	r4,16
107	blt	6f
108err2;	std	r0,0(r3)
109err2;	std	r0,8(r3)
110	addi	r3,r3,16
111	addi	r4,r4,-16
112
113	/* Up to 15 bytes to go */
1146:	mr	r8,r3
115	clrldi	r4,r4,(64-4)
116	mtocrf	0x01,r4
117	bf	cr7*4+0,7f
118err1;	std	r0,0(r3)
119	addi	r3,r3,8
120
1217:	bf	cr7*4+1,8f
122err1;	stw	r0,0(r3)
123	addi	r3,r3,4
124
1258:	bf	cr7*4+2,9f
126err1;	sth	r0,0(r3)
127	addi	r3,r3,2
128
1299:	bf	cr7*4+3,10f
130err1;	stb	r0,0(r3)
131
13210:	li	r3,0
133	blr
134
135.Llong_clear:
136	ld	r5,PPC64_CACHES@toc(r2)
137
138	bf	cr7*4+0,11f
139err2;	std	r0,0(r3)
140	addi	r3,r3,8
141	addi	r4,r4,-8
142
143	/* Destination is 16 byte aligned, need to get it cache block aligned */
14411:	lwz	r7,DCACHEL1LOGBLOCKSIZE(r5)
145	lwz	r9,DCACHEL1BLOCKSIZE(r5)
146
147	/*
148	 * With worst case alignment the long clear loop takes a minimum
149	 * of 1 byte less than 2 cachelines.
150	 */
151	sldi	r10,r9,2
152	cmpd	r4,r10
153	blt	.Lmedium_clear
154
155	neg	r6,r3
156	addi	r10,r9,-1
157	and.	r5,r6,r10
158	beq	13f
159
160	srdi	r6,r5,4
161	mtctr	r6
162	mr	r8,r3
16312:
164err1;	std	r0,0(r3)
165err1;	std	r0,8(r3)
166	addi	r3,r3,16
167	bdnz	12b
168
169	sub	r4,r4,r5
170
17113:	srd	r6,r4,r7
172	mtctr	r6
173	mr	r8,r3
17414:
175err1;	dcbz	0,r3
176	add	r3,r3,r9
177	bdnz	14b
178
179	and	r4,r4,r10
180
181	cmpdi	r4,32
182	blt	.Lshort_clear
183	b	.Lmedium_clear
184EXPORT_SYMBOL(__arch_clear_user)