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linux-next/arch/powerpc/lib/string_64.S
Benjamin Herrenschmidt bd067f83b0 powerpc/64: Fix naming of cache block vs. cache line
In a number of places we called "cache line size" what is actually
the cache block size, which in the powerpc architecture, means the
effective size to use with cache management instructions (it can
be different from the actual cache line size).

We fix the naming across the board and properly retrieve both
pieces of information when available in the device-tree.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-06 19:46:04 +11:00

197 lines
3.4 KiB
ArmAsm

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) IBM Corporation, 2012
*
* Author: Anton Blanchard <anton@au.ibm.com>
*/
#include <asm/ppc_asm.h>
#include <asm/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/export.h>
.section ".toc","aw"
PPC64_CACHES:
.tc ppc64_caches[TC],ppc64_caches
.section ".text"
/**
* __clear_user: - Zero a block of memory in user space, with less checking.
* @to: Destination address, in user space.
* @n: Number of bytes to zero.
*
* Zero a block of memory in user space. Caller must check
* the specified block with access_ok() before calling this function.
*
* Returns number of bytes that could not be cleared.
* On success, this will be zero.
*/
.macro err1
100:
EX_TABLE(100b,.Ldo_err1)
.endm
.macro err2
200:
EX_TABLE(200b,.Ldo_err2)
.endm
.macro err3
300:
EX_TABLE(300b,.Ldo_err3)
.endm
.Ldo_err1:
mr r3,r8
.Ldo_err2:
mtctr r4
1:
err3; stb r0,0(r3)
addi r3,r3,1
addi r4,r4,-1
bdnz 1b
.Ldo_err3:
mr r3,r4
blr
_GLOBAL_TOC(__clear_user)
cmpdi r4,32
neg r6,r3
li r0,0
blt .Lshort_clear
mr r8,r3
mtocrf 0x01,r6
clrldi r6,r6,(64-3)
/* Get the destination 8 byte aligned */
bf cr7*4+3,1f
err1; stb r0,0(r3)
addi r3,r3,1
1: bf cr7*4+2,2f
err1; sth r0,0(r3)
addi r3,r3,2
2: bf cr7*4+1,3f
err1; stw r0,0(r3)
addi r3,r3,4
3: sub r4,r4,r6
cmpdi r4,32
cmpdi cr1,r4,512
blt .Lshort_clear
bgt cr1,.Llong_clear
.Lmedium_clear:
srdi r6,r4,5
mtctr r6
/* Do 32 byte chunks */
4:
err2; std r0,0(r3)
err2; std r0,8(r3)
err2; std r0,16(r3)
err2; std r0,24(r3)
addi r3,r3,32
addi r4,r4,-32
bdnz 4b
.Lshort_clear:
/* up to 31 bytes to go */
cmpdi r4,16
blt 6f
err2; std r0,0(r3)
err2; std r0,8(r3)
addi r3,r3,16
addi r4,r4,-16
/* Up to 15 bytes to go */
6: mr r8,r3
clrldi r4,r4,(64-4)
mtocrf 0x01,r4
bf cr7*4+0,7f
err1; std r0,0(r3)
addi r3,r3,8
7: bf cr7*4+1,8f
err1; stw r0,0(r3)
addi r3,r3,4
8: bf cr7*4+2,9f
err1; sth r0,0(r3)
addi r3,r3,2
9: bf cr7*4+3,10f
err1; stb r0,0(r3)
10: li r3,0
blr
.Llong_clear:
ld r5,PPC64_CACHES@toc(r2)
bf cr7*4+0,11f
err2; std r0,0(r3)
addi r3,r3,8
addi r4,r4,-8
/* Destination is 16 byte aligned, need to get it cache block aligned */
11: lwz r7,DCACHEL1LOGBLOCKSIZE(r5)
lwz r9,DCACHEL1BLOCKSIZE(r5)
/*
* With worst case alignment the long clear loop takes a minimum
* of 1 byte less than 2 cachelines.
*/
sldi r10,r9,2
cmpd r4,r10
blt .Lmedium_clear
neg r6,r3
addi r10,r9,-1
and. r5,r6,r10
beq 13f
srdi r6,r5,4
mtctr r6
mr r8,r3
12:
err1; std r0,0(r3)
err1; std r0,8(r3)
addi r3,r3,16
bdnz 12b
sub r4,r4,r5
13: srd r6,r4,r7
mtctr r6
mr r8,r3
14:
err1; dcbz r0,r3
add r3,r3,r9
bdnz 14b
and r4,r4,r10
cmpdi r4,32
blt .Lshort_clear
b .Lmedium_clear
EXPORT_SYMBOL(__clear_user)