linux/arch/parisc/lib/lusercopy.S
Thomas Gleixner 660662f857 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 150
Based on 1 normalized pattern(s):

  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 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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 42 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190524100845.259718220@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:25:19 -07:00

413 lines
9.9 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* User Space Access Routines
*
* Copyright (C) 2000-2002 Hewlett-Packard (John Marvin)
* Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
* Copyright (C) 2001 Matthieu Delahaye <delahaym at esiee.fr>
* Copyright (C) 2003 Randolph Chung <tausq with parisc-linux.org>
* Copyright (C) 2017 Helge Deller <deller@gmx.de>
* Copyright (C) 2017 John David Anglin <dave.anglin@bell.net>
*/
/*
* These routines still have plenty of room for optimization
* (word & doubleword load/store, dual issue, store hints, etc.).
*/
/*
* The following routines assume that space register 3 (sr3) contains
* the space id associated with the current users address space.
*/
.text
#include <asm/assembly.h>
#include <asm/errno.h>
#include <linux/linkage.h>
/*
* get_sr gets the appropriate space value into
* sr1 for kernel/user space access, depending
* on the flag stored in the task structure.
*/
.macro get_sr
mfctl %cr30,%r1
ldw TI_SEGMENT(%r1),%r22
mfsp %sr3,%r1
or,<> %r22,%r0,%r0
copy %r0,%r1
mtsp %r1,%sr1
.endm
/*
* unsigned long lclear_user(void *to, unsigned long n)
*
* Returns 0 for success.
* otherwise, returns number of bytes not transferred.
*/
ENTRY_CFI(lclear_user)
comib,=,n 0,%r25,$lclu_done
get_sr
$lclu_loop:
addib,<> -1,%r25,$lclu_loop
1: stbs,ma %r0,1(%sr1,%r26)
$lclu_done:
bv %r0(%r2)
copy %r25,%r28
2: b $lclu_done
ldo 1(%r25),%r25
ASM_EXCEPTIONTABLE_ENTRY(1b,2b)
ENDPROC_CFI(lclear_user)
/*
* long lstrnlen_user(char *s, long n)
*
* Returns 0 if exception before zero byte or reaching N,
* N+1 if N would be exceeded,
* else strlen + 1 (i.e. includes zero byte).
*/
ENTRY_CFI(lstrnlen_user)
comib,= 0,%r25,$lslen_nzero
copy %r26,%r24
get_sr
1: ldbs,ma 1(%sr1,%r26),%r1
$lslen_loop:
comib,=,n 0,%r1,$lslen_done
addib,<> -1,%r25,$lslen_loop
2: ldbs,ma 1(%sr1,%r26),%r1
$lslen_done:
bv %r0(%r2)
sub %r26,%r24,%r28
$lslen_nzero:
b $lslen_done
ldo 1(%r26),%r26 /* special case for N == 0 */
3: b $lslen_done
copy %r24,%r26 /* reset r26 so 0 is returned on fault */
ASM_EXCEPTIONTABLE_ENTRY(1b,3b)
ASM_EXCEPTIONTABLE_ENTRY(2b,3b)
ENDPROC_CFI(lstrnlen_user)
/*
* unsigned long pa_memcpy(void *dstp, const void *srcp, unsigned long len)
*
* Inputs:
* - sr1 already contains space of source region
* - sr2 already contains space of destination region
*
* Returns:
* - number of bytes that could not be copied.
* On success, this will be zero.
*
* This code is based on a C-implementation of a copy routine written by
* Randolph Chung, which in turn was derived from the glibc.
*
* Several strategies are tried to try to get the best performance for various
* conditions. In the optimal case, we copy by loops that copy 32- or 16-bytes
* at a time using general registers. Unaligned copies are handled either by
* aligning the destination and then using shift-and-write method, or in a few
* cases by falling back to a byte-at-a-time copy.
*
* Testing with various alignments and buffer sizes shows that this code is
* often >10x faster than a simple byte-at-a-time copy, even for strangely
* aligned operands. It is interesting to note that the glibc version of memcpy
* (written in C) is actually quite fast already. This routine is able to beat
* it by 30-40% for aligned copies because of the loop unrolling, but in some
* cases the glibc version is still slightly faster. This lends more
* credibility that gcc can generate very good code as long as we are careful.
*
* Possible optimizations:
* - add cache prefetching
* - try not to use the post-increment address modifiers; they may create
* additional interlocks. Assumption is that those were only efficient on old
* machines (pre PA8000 processors)
*/
dst = arg0
src = arg1
len = arg2
end = arg3
t1 = r19
t2 = r20
t3 = r21
t4 = r22
srcspc = sr1
dstspc = sr2
t0 = r1
a1 = t1
a2 = t2
a3 = t3
a0 = t4
save_src = ret0
save_dst = ret1
save_len = r31
ENTRY_CFI(pa_memcpy)
/* Last destination address */
add dst,len,end
/* short copy with less than 16 bytes? */
cmpib,COND(>>=),n 15,len,.Lbyte_loop
/* same alignment? */
xor src,dst,t0
extru t0,31,2,t1
cmpib,<>,n 0,t1,.Lunaligned_copy
#ifdef CONFIG_64BIT
/* only do 64-bit copies if we can get aligned. */
extru t0,31,3,t1
cmpib,<>,n 0,t1,.Lalign_loop32
/* loop until we are 64-bit aligned */
.Lalign_loop64:
extru dst,31,3,t1
cmpib,=,n 0,t1,.Lcopy_loop_16_start
20: ldb,ma 1(srcspc,src),t1
21: stb,ma t1,1(dstspc,dst)
b .Lalign_loop64
ldo -1(len),len
ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done)
.Lcopy_loop_16_start:
ldi 31,t0
.Lcopy_loop_16:
cmpb,COND(>>=),n t0,len,.Lword_loop
10: ldd 0(srcspc,src),t1
11: ldd 8(srcspc,src),t2
ldo 16(src),src
12: std,ma t1,8(dstspc,dst)
13: std,ma t2,8(dstspc,dst)
14: ldd 0(srcspc,src),t1
15: ldd 8(srcspc,src),t2
ldo 16(src),src
16: std,ma t1,8(dstspc,dst)
17: std,ma t2,8(dstspc,dst)
ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(11b,.Lcopy16_fault)
ASM_EXCEPTIONTABLE_ENTRY(12b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(13b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(14b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(15b,.Lcopy16_fault)
ASM_EXCEPTIONTABLE_ENTRY(16b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(17b,.Lcopy_done)
b .Lcopy_loop_16
ldo -32(len),len
.Lword_loop:
cmpib,COND(>>=),n 3,len,.Lbyte_loop
20: ldw,ma 4(srcspc,src),t1
21: stw,ma t1,4(dstspc,dst)
b .Lword_loop
ldo -4(len),len
ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done)
#endif /* CONFIG_64BIT */
/* loop until we are 32-bit aligned */
.Lalign_loop32:
extru dst,31,2,t1
cmpib,=,n 0,t1,.Lcopy_loop_8
20: ldb,ma 1(srcspc,src),t1
21: stb,ma t1,1(dstspc,dst)
b .Lalign_loop32
ldo -1(len),len
ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done)
.Lcopy_loop_8:
cmpib,COND(>>=),n 15,len,.Lbyte_loop
10: ldw 0(srcspc,src),t1
11: ldw 4(srcspc,src),t2
12: stw,ma t1,4(dstspc,dst)
13: stw,ma t2,4(dstspc,dst)
14: ldw 8(srcspc,src),t1
15: ldw 12(srcspc,src),t2
ldo 16(src),src
16: stw,ma t1,4(dstspc,dst)
17: stw,ma t2,4(dstspc,dst)
ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(11b,.Lcopy8_fault)
ASM_EXCEPTIONTABLE_ENTRY(12b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(13b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(14b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(15b,.Lcopy8_fault)
ASM_EXCEPTIONTABLE_ENTRY(16b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(17b,.Lcopy_done)
b .Lcopy_loop_8
ldo -16(len),len
.Lbyte_loop:
cmpclr,COND(<>) len,%r0,%r0
b,n .Lcopy_done
20: ldb 0(srcspc,src),t1
ldo 1(src),src
21: stb,ma t1,1(dstspc,dst)
b .Lbyte_loop
ldo -1(len),len
ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done)
.Lcopy_done:
bv %r0(%r2)
sub end,dst,ret0
/* src and dst are not aligned the same way. */
/* need to go the hard way */
.Lunaligned_copy:
/* align until dst is 32bit-word-aligned */
extru dst,31,2,t1
cmpib,=,n 0,t1,.Lcopy_dstaligned
20: ldb 0(srcspc,src),t1
ldo 1(src),src
21: stb,ma t1,1(dstspc,dst)
b .Lunaligned_copy
ldo -1(len),len
ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done)
.Lcopy_dstaligned:
/* store src, dst and len in safe place */
copy src,save_src
copy dst,save_dst
copy len,save_len
/* len now needs give number of words to copy */
SHRREG len,2,len
/*
* Copy from a not-aligned src to an aligned dst using shifts.
* Handles 4 words per loop.
*/
depw,z src,28,2,t0
subi 32,t0,t0
mtsar t0
extru len,31,2,t0
cmpib,= 2,t0,.Lcase2
/* Make src aligned by rounding it down. */
depi 0,31,2,src
cmpiclr,<> 3,t0,%r0
b,n .Lcase3
cmpiclr,<> 1,t0,%r0
b,n .Lcase1
.Lcase0:
cmpb,COND(=) %r0,len,.Lcda_finish
nop
1: ldw,ma 4(srcspc,src), a3
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
1: ldw,ma 4(srcspc,src), a0
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
b,n .Ldo3
.Lcase1:
1: ldw,ma 4(srcspc,src), a2
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
1: ldw,ma 4(srcspc,src), a3
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
ldo -1(len),len
cmpb,COND(=),n %r0,len,.Ldo0
.Ldo4:
1: ldw,ma 4(srcspc,src), a0
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
shrpw a2, a3, %sar, t0
1: stw,ma t0, 4(dstspc,dst)
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done)
.Ldo3:
1: ldw,ma 4(srcspc,src), a1
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
shrpw a3, a0, %sar, t0
1: stw,ma t0, 4(dstspc,dst)
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done)
.Ldo2:
1: ldw,ma 4(srcspc,src), a2
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
shrpw a0, a1, %sar, t0
1: stw,ma t0, 4(dstspc,dst)
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done)
.Ldo1:
1: ldw,ma 4(srcspc,src), a3
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
shrpw a1, a2, %sar, t0
1: stw,ma t0, 4(dstspc,dst)
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done)
ldo -4(len),len
cmpb,COND(<>) %r0,len,.Ldo4
nop
.Ldo0:
shrpw a2, a3, %sar, t0
1: stw,ma t0, 4(dstspc,dst)
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done)
.Lcda_rdfault:
.Lcda_finish:
/* calculate new src, dst and len and jump to byte-copy loop */
sub dst,save_dst,t0
add save_src,t0,src
b .Lbyte_loop
sub save_len,t0,len
.Lcase3:
1: ldw,ma 4(srcspc,src), a0
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
1: ldw,ma 4(srcspc,src), a1
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
b .Ldo2
ldo 1(len),len
.Lcase2:
1: ldw,ma 4(srcspc,src), a1
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
1: ldw,ma 4(srcspc,src), a2
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
b .Ldo1
ldo 2(len),len
/* fault exception fixup handlers: */
#ifdef CONFIG_64BIT
.Lcopy16_fault:
b .Lcopy_done
10: std,ma t1,8(dstspc,dst)
ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done)
#endif
.Lcopy8_fault:
b .Lcopy_done
10: stw,ma t1,4(dstspc,dst)
ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done)
ENDPROC_CFI(pa_memcpy)
.end