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kernel_optimize_test/arch/ia64/lib/memcpy_mck.S
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license 
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Itanium 2-optimized version of memcpy and copy_user function
*
* Inputs:
* in0: destination address
* in1: source address
* in2: number of bytes to copy
* Output:
* for memcpy: return dest
* for copy_user: return 0 if success,
* or number of byte NOT copied if error occurred.
*
* Copyright (C) 2002 Intel Corp.
* Copyright (C) 2002 Ken Chen <kenneth.w.chen@intel.com>
*/
#include <asm/asmmacro.h>
#include <asm/page.h>
#include <asm/export.h>
#define EK(y...) EX(y)
/* McKinley specific optimization */
#define retval r8
#define saved_pfs r31
#define saved_lc r10
#define saved_pr r11
#define saved_in0 r14
#define saved_in1 r15
#define saved_in2 r16
#define src0 r2
#define src1 r3
#define dst0 r17
#define dst1 r18
#define cnt r9
/* r19-r30 are temp for each code section */
#define PREFETCH_DIST 8
#define src_pre_mem r19
#define dst_pre_mem r20
#define src_pre_l2 r21
#define dst_pre_l2 r22
#define t1 r23
#define t2 r24
#define t3 r25
#define t4 r26
#define t5 t1 // alias!
#define t6 t2 // alias!
#define t7 t3 // alias!
#define n8 r27
#define t9 t5 // alias!
#define t10 t4 // alias!
#define t11 t7 // alias!
#define t12 t6 // alias!
#define t14 t10 // alias!
#define t13 r28
#define t15 r29
#define tmp r30
/* defines for long_copy block */
#define A 0
#define B (PREFETCH_DIST)
#define C (B + PREFETCH_DIST)
#define D (C + 1)
#define N (D + 1)
#define Nrot ((N + 7) & ~7)
/* alias */
#define in0 r32
#define in1 r33
#define in2 r34
GLOBAL_ENTRY(memcpy)
and r28=0x7,in0
and r29=0x7,in1
mov f6=f0
mov retval=in0
br.cond.sptk .common_code
;;
END(memcpy)
EXPORT_SYMBOL(memcpy)
GLOBAL_ENTRY(__copy_user)
.prologue
// check dest alignment
and r28=0x7,in0
and r29=0x7,in1
mov f6=f1
mov saved_in0=in0 // save dest pointer
mov saved_in1=in1 // save src pointer
mov retval=r0 // initialize return value
;;
.common_code:
cmp.gt p15,p0=8,in2 // check for small size
cmp.ne p13,p0=0,r28 // check dest alignment
cmp.ne p14,p0=0,r29 // check src alignment
add src0=0,in1
sub r30=8,r28 // for .align_dest
mov saved_in2=in2 // save len
;;
add dst0=0,in0
add dst1=1,in0 // dest odd index
cmp.le p6,p0 = 1,r30 // for .align_dest
(p15) br.cond.dpnt .memcpy_short
(p13) br.cond.dpnt .align_dest
(p14) br.cond.dpnt .unaligned_src
;;
// both dest and src are aligned on 8-byte boundary
.aligned_src:
.save ar.pfs, saved_pfs
alloc saved_pfs=ar.pfs,3,Nrot-3,0,Nrot
.save pr, saved_pr
mov saved_pr=pr
shr.u cnt=in2,7 // this much cache line
;;
cmp.lt p6,p0=2*PREFETCH_DIST,cnt
cmp.lt p7,p8=1,cnt
.save ar.lc, saved_lc
mov saved_lc=ar.lc
.body
add cnt=-1,cnt
add src_pre_mem=0,in1 // prefetch src pointer
add dst_pre_mem=0,in0 // prefetch dest pointer
;;
(p7) mov ar.lc=cnt // prefetch count
(p8) mov ar.lc=r0
(p6) br.cond.dpnt .long_copy
;;
.prefetch:
lfetch.fault [src_pre_mem], 128
lfetch.fault.excl [dst_pre_mem], 128
br.cloop.dptk.few .prefetch
;;
.medium_copy:
and tmp=31,in2 // copy length after iteration
shr.u r29=in2,5 // number of 32-byte iteration
add dst1=8,dst0 // 2nd dest pointer
;;
add cnt=-1,r29 // ctop iteration adjustment
cmp.eq p10,p0=r29,r0 // do we really need to loop?
add src1=8,src0 // 2nd src pointer
cmp.le p6,p0=8,tmp
;;
cmp.le p7,p0=16,tmp
mov ar.lc=cnt // loop setup
cmp.eq p16,p17 = r0,r0
mov ar.ec=2
(p10) br.dpnt.few .aligned_src_tail
;;
TEXT_ALIGN(32)
1:
EX(.ex_handler, (p16) ld8 r34=[src0],16)
EK(.ex_handler, (p16) ld8 r38=[src1],16)
EX(.ex_handler, (p17) st8 [dst0]=r33,16)
EK(.ex_handler, (p17) st8 [dst1]=r37,16)
;;
EX(.ex_handler, (p16) ld8 r32=[src0],16)
EK(.ex_handler, (p16) ld8 r36=[src1],16)
EX(.ex_handler, (p16) st8 [dst0]=r34,16)
EK(.ex_handler, (p16) st8 [dst1]=r38,16)
br.ctop.dptk.few 1b
;;
.aligned_src_tail:
EX(.ex_handler, (p6) ld8 t1=[src0])
mov ar.lc=saved_lc
mov ar.pfs=saved_pfs
EX(.ex_hndlr_s, (p7) ld8 t2=[src1],8)
cmp.le p8,p0=24,tmp
and r21=-8,tmp
;;
EX(.ex_hndlr_s, (p8) ld8 t3=[src1])
EX(.ex_handler, (p6) st8 [dst0]=t1) // store byte 1
and in2=7,tmp // remaining length
EX(.ex_hndlr_d, (p7) st8 [dst1]=t2,8) // store byte 2
add src0=src0,r21 // setting up src pointer
add dst0=dst0,r21 // setting up dest pointer
;;
EX(.ex_handler, (p8) st8 [dst1]=t3) // store byte 3
mov pr=saved_pr,-1
br.dptk.many .memcpy_short
;;
/* code taken from copy_page_mck */
.long_copy:
.rotr v[2*PREFETCH_DIST]
.rotp p[N]
mov src_pre_mem = src0
mov pr.rot = 0x10000
mov ar.ec = 1 // special unrolled loop
mov dst_pre_mem = dst0
add src_pre_l2 = 8*8, src0
add dst_pre_l2 = 8*8, dst0
;;
add src0 = 8, src_pre_mem // first t1 src
mov ar.lc = 2*PREFETCH_DIST - 1
shr.u cnt=in2,7 // number of lines
add src1 = 3*8, src_pre_mem // first t3 src
add dst0 = 8, dst_pre_mem // first t1 dst
add dst1 = 3*8, dst_pre_mem // first t3 dst
;;
and tmp=127,in2 // remaining bytes after this block
add cnt = -(2*PREFETCH_DIST) - 1, cnt
// same as .line_copy loop, but with all predicated-off instructions removed:
.prefetch_loop:
EX(.ex_hndlr_lcpy_1, (p[A]) ld8 v[A] = [src_pre_mem], 128) // M0
EK(.ex_hndlr_lcpy_1, (p[B]) st8 [dst_pre_mem] = v[B], 128) // M2
br.ctop.sptk .prefetch_loop
;;
cmp.eq p16, p0 = r0, r0 // reset p16 to 1
mov ar.lc = cnt
mov ar.ec = N // # of stages in pipeline
;;
.line_copy:
EX(.ex_handler, (p[D]) ld8 t2 = [src0], 3*8) // M0
EK(.ex_handler, (p[D]) ld8 t4 = [src1], 3*8) // M1
EX(.ex_handler_lcpy, (p[B]) st8 [dst_pre_mem] = v[B], 128) // M2 prefetch dst from memory
EK(.ex_handler_lcpy, (p[D]) st8 [dst_pre_l2] = n8, 128) // M3 prefetch dst from L2
;;
EX(.ex_handler_lcpy, (p[A]) ld8 v[A] = [src_pre_mem], 128) // M0 prefetch src from memory
EK(.ex_handler_lcpy, (p[C]) ld8 n8 = [src_pre_l2], 128) // M1 prefetch src from L2
EX(.ex_handler, (p[D]) st8 [dst0] = t1, 8) // M2
EK(.ex_handler, (p[D]) st8 [dst1] = t3, 8) // M3
;;
EX(.ex_handler, (p[D]) ld8 t5 = [src0], 8)
EK(.ex_handler, (p[D]) ld8 t7 = [src1], 3*8)
EX(.ex_handler, (p[D]) st8 [dst0] = t2, 3*8)
EK(.ex_handler, (p[D]) st8 [dst1] = t4, 3*8)
;;
EX(.ex_handler, (p[D]) ld8 t6 = [src0], 3*8)
EK(.ex_handler, (p[D]) ld8 t10 = [src1], 8)
EX(.ex_handler, (p[D]) st8 [dst0] = t5, 8)
EK(.ex_handler, (p[D]) st8 [dst1] = t7, 3*8)
;;
EX(.ex_handler, (p[D]) ld8 t9 = [src0], 3*8)
EK(.ex_handler, (p[D]) ld8 t11 = [src1], 3*8)
EX(.ex_handler, (p[D]) st8 [dst0] = t6, 3*8)
EK(.ex_handler, (p[D]) st8 [dst1] = t10, 8)
;;
EX(.ex_handler, (p[D]) ld8 t12 = [src0], 8)
EK(.ex_handler, (p[D]) ld8 t14 = [src1], 8)
EX(.ex_handler, (p[D]) st8 [dst0] = t9, 3*8)
EK(.ex_handler, (p[D]) st8 [dst1] = t11, 3*8)
;;
EX(.ex_handler, (p[D]) ld8 t13 = [src0], 4*8)
EK(.ex_handler, (p[D]) ld8 t15 = [src1], 4*8)
EX(.ex_handler, (p[D]) st8 [dst0] = t12, 8)
EK(.ex_handler, (p[D]) st8 [dst1] = t14, 8)
;;
EX(.ex_handler, (p[C]) ld8 t1 = [src0], 8)
EK(.ex_handler, (p[C]) ld8 t3 = [src1], 8)
EX(.ex_handler, (p[D]) st8 [dst0] = t13, 4*8)
EK(.ex_handler, (p[D]) st8 [dst1] = t15, 4*8)
br.ctop.sptk .line_copy
;;
add dst0=-8,dst0
add src0=-8,src0
mov in2=tmp
.restore sp
br.sptk.many .medium_copy
;;
#define BLOCK_SIZE 128*32
#define blocksize r23
#define curlen r24
// dest is on 8-byte boundary, src is not. We need to do
// ld8-ld8, shrp, then st8. Max 8 byte copy per cycle.
.unaligned_src:
.prologue
.save ar.pfs, saved_pfs
alloc saved_pfs=ar.pfs,3,5,0,8
.save ar.lc, saved_lc
mov saved_lc=ar.lc
.save pr, saved_pr
mov saved_pr=pr
.body
.4k_block:
mov saved_in0=dst0 // need to save all input arguments
mov saved_in2=in2
mov blocksize=BLOCK_SIZE
;;
cmp.lt p6,p7=blocksize,in2
mov saved_in1=src0
;;
(p6) mov in2=blocksize
;;
shr.u r21=in2,7 // this much cache line
shr.u r22=in2,4 // number of 16-byte iteration
and curlen=15,in2 // copy length after iteration
and r30=7,src0 // source alignment
;;
cmp.lt p7,p8=1,r21
add cnt=-1,r21
;;
add src_pre_mem=0,src0 // prefetch src pointer
add dst_pre_mem=0,dst0 // prefetch dest pointer
and src0=-8,src0 // 1st src pointer
(p7) mov ar.lc = cnt
(p8) mov ar.lc = r0
;;
TEXT_ALIGN(32)
1: lfetch.fault [src_pre_mem], 128
lfetch.fault.excl [dst_pre_mem], 128
br.cloop.dptk.few 1b
;;
shladd dst1=r22,3,dst0 // 2nd dest pointer
shladd src1=r22,3,src0 // 2nd src pointer
cmp.eq p8,p9=r22,r0 // do we really need to loop?
cmp.le p6,p7=8,curlen; // have at least 8 byte remaining?
add cnt=-1,r22 // ctop iteration adjustment
;;
EX(.ex_handler, (p9) ld8 r33=[src0],8) // loop primer
EK(.ex_handler, (p9) ld8 r37=[src1],8)
(p8) br.dpnt.few .noloop
;;
// The jump address is calculated based on src alignment. The COPYU
// macro below need to confine its size to power of two, so an entry
// can be caulated using shl instead of an expensive multiply. The
// size is then hard coded by the following #define to match the
// actual size. This make it somewhat tedious when COPYU macro gets
// changed and this need to be adjusted to match.
#define LOOP_SIZE 6
1:
mov r29=ip // jmp_table thread
mov ar.lc=cnt
;;
add r29=.jump_table - 1b - (.jmp1-.jump_table), r29
shl r28=r30, LOOP_SIZE // jmp_table thread
mov ar.ec=2 // loop setup
;;
add r29=r29,r28 // jmp_table thread
cmp.eq p16,p17=r0,r0
;;
mov b6=r29 // jmp_table thread
;;
br.cond.sptk.few b6
// for 8-15 byte case
// We will skip the loop, but need to replicate the side effect
// that the loop produces.
.noloop:
EX(.ex_handler, (p6) ld8 r37=[src1],8)
add src0=8,src0
(p6) shl r25=r30,3
;;
EX(.ex_handler, (p6) ld8 r27=[src1])
(p6) shr.u r28=r37,r25
(p6) sub r26=64,r25
;;
(p6) shl r27=r27,r26
;;
(p6) or r21=r28,r27
.unaligned_src_tail:
/* check if we have more than blocksize to copy, if so go back */
cmp.gt p8,p0=saved_in2,blocksize
;;
(p8) add dst0=saved_in0,blocksize
(p8) add src0=saved_in1,blocksize
(p8) sub in2=saved_in2,blocksize
(p8) br.dpnt .4k_block
;;
/* we have up to 15 byte to copy in the tail.
* part of work is already done in the jump table code
* we are at the following state.
* src side:
*
* xxxxxx xx <----- r21 has xxxxxxxx already
* -------- -------- --------
* 0 8 16
* ^
* |
* src1
*
* dst
* -------- -------- --------
* ^
* |
* dst1
*/
EX(.ex_handler, (p6) st8 [dst1]=r21,8) // more than 8 byte to copy
(p6) add curlen=-8,curlen // update length
mov ar.pfs=saved_pfs
;;
mov ar.lc=saved_lc
mov pr=saved_pr,-1
mov in2=curlen // remaining length
mov dst0=dst1 // dest pointer
add src0=src1,r30 // forward by src alignment
;;
// 7 byte or smaller.
.memcpy_short:
cmp.le p8,p9 = 1,in2
cmp.le p10,p11 = 2,in2
cmp.le p12,p13 = 3,in2
cmp.le p14,p15 = 4,in2
add src1=1,src0 // second src pointer
add dst1=1,dst0 // second dest pointer
;;
EX(.ex_handler_short, (p8) ld1 t1=[src0],2)
EK(.ex_handler_short, (p10) ld1 t2=[src1],2)
(p9) br.ret.dpnt rp // 0 byte copy
;;
EX(.ex_handler_short, (p8) st1 [dst0]=t1,2)
EK(.ex_handler_short, (p10) st1 [dst1]=t2,2)
(p11) br.ret.dpnt rp // 1 byte copy
EX(.ex_handler_short, (p12) ld1 t3=[src0],2)
EK(.ex_handler_short, (p14) ld1 t4=[src1],2)
(p13) br.ret.dpnt rp // 2 byte copy
;;
cmp.le p6,p7 = 5,in2
cmp.le p8,p9 = 6,in2
cmp.le p10,p11 = 7,in2
EX(.ex_handler_short, (p12) st1 [dst0]=t3,2)
EK(.ex_handler_short, (p14) st1 [dst1]=t4,2)
(p15) br.ret.dpnt rp // 3 byte copy
;;
EX(.ex_handler_short, (p6) ld1 t5=[src0],2)
EK(.ex_handler_short, (p8) ld1 t6=[src1],2)
(p7) br.ret.dpnt rp // 4 byte copy
;;
EX(.ex_handler_short, (p6) st1 [dst0]=t5,2)
EK(.ex_handler_short, (p8) st1 [dst1]=t6,2)
(p9) br.ret.dptk rp // 5 byte copy
EX(.ex_handler_short, (p10) ld1 t7=[src0],2)
(p11) br.ret.dptk rp // 6 byte copy
;;
EX(.ex_handler_short, (p10) st1 [dst0]=t7,2)
br.ret.dptk rp // done all cases
/* Align dest to nearest 8-byte boundary. We know we have at
* least 7 bytes to copy, enough to crawl to 8-byte boundary.
* Actual number of byte to crawl depend on the dest alignment.
* 7 byte or less is taken care at .memcpy_short
* src0 - source even index
* src1 - source odd index
* dst0 - dest even index
* dst1 - dest odd index
* r30 - distance to 8-byte boundary
*/
.align_dest:
add src1=1,in1 // source odd index
cmp.le p7,p0 = 2,r30 // for .align_dest
cmp.le p8,p0 = 3,r30 // for .align_dest
EX(.ex_handler_short, (p6) ld1 t1=[src0],2)
cmp.le p9,p0 = 4,r30 // for .align_dest
cmp.le p10,p0 = 5,r30
;;
EX(.ex_handler_short, (p7) ld1 t2=[src1],2)
EK(.ex_handler_short, (p8) ld1 t3=[src0],2)
cmp.le p11,p0 = 6,r30
EX(.ex_handler_short, (p6) st1 [dst0] = t1,2)
cmp.le p12,p0 = 7,r30
;;
EX(.ex_handler_short, (p9) ld1 t4=[src1],2)
EK(.ex_handler_short, (p10) ld1 t5=[src0],2)
EX(.ex_handler_short, (p7) st1 [dst1] = t2,2)
EK(.ex_handler_short, (p8) st1 [dst0] = t3,2)
;;
EX(.ex_handler_short, (p11) ld1 t6=[src1],2)
EK(.ex_handler_short, (p12) ld1 t7=[src0],2)
cmp.eq p6,p7=r28,r29
EX(.ex_handler_short, (p9) st1 [dst1] = t4,2)
EK(.ex_handler_short, (p10) st1 [dst0] = t5,2)
sub in2=in2,r30
;;
EX(.ex_handler_short, (p11) st1 [dst1] = t6,2)
EK(.ex_handler_short, (p12) st1 [dst0] = t7)
add dst0=in0,r30 // setup arguments
add src0=in1,r30
(p6) br.cond.dptk .aligned_src
(p7) br.cond.dpnt .unaligned_src
;;
/* main loop body in jump table format */
#define COPYU(shift) \
1: \
EX(.ex_handler, (p16) ld8 r32=[src0],8); /* 1 */ \
EK(.ex_handler, (p16) ld8 r36=[src1],8); \
(p17) shrp r35=r33,r34,shift;; /* 1 */ \
EX(.ex_handler, (p6) ld8 r22=[src1]); /* common, prime for tail section */ \
nop.m 0; \
(p16) shrp r38=r36,r37,shift; \
EX(.ex_handler, (p17) st8 [dst0]=r35,8); /* 1 */ \
EK(.ex_handler, (p17) st8 [dst1]=r39,8); \
br.ctop.dptk.few 1b;; \
(p7) add src1=-8,src1; /* back out for <8 byte case */ \
shrp r21=r22,r38,shift; /* speculative work */ \
br.sptk.few .unaligned_src_tail /* branch out of jump table */ \
;;
TEXT_ALIGN(32)
.jump_table:
COPYU(8) // unaligned cases
.jmp1:
COPYU(16)
COPYU(24)
COPYU(32)
COPYU(40)
COPYU(48)
COPYU(56)
#undef A
#undef B
#undef C
#undef D
/*
* Due to lack of local tag support in gcc 2.x assembler, it is not clear which
* instruction failed in the bundle. The exception algorithm is that we
* first figure out the faulting address, then detect if there is any
* progress made on the copy, if so, redo the copy from last known copied
* location up to the faulting address (exclusive). In the copy_from_user
* case, remaining byte in kernel buffer will be zeroed.
*
* Take copy_from_user as an example, in the code there are multiple loads
* in a bundle and those multiple loads could span over two pages, the
* faulting address is calculated as page_round_down(max(src0, src1)).
* This is based on knowledge that if we can access one byte in a page, we
* can access any byte in that page.
*
* predicate used in the exception handler:
* p6-p7: direction
* p10-p11: src faulting addr calculation
* p12-p13: dst faulting addr calculation
*/
#define A r19
#define B r20
#define C r21
#define D r22
#define F r28
#define saved_retval loc0
#define saved_rtlink loc1
#define saved_pfs_stack loc2
.ex_hndlr_s:
add src0=8,src0
br.sptk .ex_handler
;;
.ex_hndlr_d:
add dst0=8,dst0
br.sptk .ex_handler
;;
.ex_hndlr_lcpy_1:
mov src1=src_pre_mem
mov dst1=dst_pre_mem
cmp.gtu p10,p11=src_pre_mem,saved_in1
cmp.gtu p12,p13=dst_pre_mem,saved_in0
;;
(p10) add src0=8,saved_in1
(p11) mov src0=saved_in1
(p12) add dst0=8,saved_in0
(p13) mov dst0=saved_in0
br.sptk .ex_handler
.ex_handler_lcpy:
// in line_copy block, the preload addresses should always ahead
// of the other two src/dst pointers. Furthermore, src1/dst1 should
// always ahead of src0/dst0.
mov src1=src_pre_mem
mov dst1=dst_pre_mem
.ex_handler:
mov pr=saved_pr,-1 // first restore pr, lc, and pfs
mov ar.lc=saved_lc
mov ar.pfs=saved_pfs
;;
.ex_handler_short: // fault occurred in these sections didn't change pr, lc, pfs
cmp.ltu p6,p7=saved_in0, saved_in1 // get the copy direction
cmp.ltu p10,p11=src0,src1
cmp.ltu p12,p13=dst0,dst1
fcmp.eq p8,p0=f6,f0 // is it memcpy?
mov tmp = dst0
;;
(p11) mov src1 = src0 // pick the larger of the two
(p13) mov dst0 = dst1 // make dst0 the smaller one
(p13) mov dst1 = tmp // and dst1 the larger one
;;
(p6) dep F = r0,dst1,0,PAGE_SHIFT // usr dst round down to page boundary
(p7) dep F = r0,src1,0,PAGE_SHIFT // usr src round down to page boundary
;;
(p6) cmp.le p14,p0=dst0,saved_in0 // no progress has been made on store
(p7) cmp.le p14,p0=src0,saved_in1 // no progress has been made on load
mov retval=saved_in2
(p8) ld1 tmp=[src1] // force an oops for memcpy call
(p8) st1 [dst1]=r0 // force an oops for memcpy call
(p14) br.ret.sptk.many rp
/*
* The remaining byte to copy is calculated as:
*
* A = (faulting_addr - orig_src) -> len to faulting ld address
* or
* (faulting_addr - orig_dst) -> len to faulting st address
* B = (cur_dst - orig_dst) -> len copied so far
* C = A - B -> len need to be copied
* D = orig_len - A -> len need to be left along
*/
(p6) sub A = F, saved_in0
(p7) sub A = F, saved_in1
clrrrb
;;
alloc saved_pfs_stack=ar.pfs,3,3,3,0
cmp.lt p8,p0=A,r0
sub B = dst0, saved_in0 // how many byte copied so far
;;
(p8) mov A = 0; // A shouldn't be negative, cap it
;;
sub C = A, B
sub D = saved_in2, A
;;
cmp.gt p8,p0=C,r0 // more than 1 byte?
mov r8=0
mov saved_retval = D
mov saved_rtlink = b0
add out0=saved_in0, B
add out1=saved_in1, B
mov out2=C
(p8) br.call.sptk.few b0=__copy_user // recursive call
;;
add saved_retval=saved_retval,r8 // above might return non-zero value
;;
mov retval=saved_retval
mov ar.pfs=saved_pfs_stack
mov b0=saved_rtlink
br.ret.sptk.many rp
/* end of McKinley specific optimization */
END(__copy_user)
EXPORT_SYMBOL(__copy_user)
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