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linux/arch/ia64/lib/memset.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

366 lines
9.1 KiB
ArmAsm
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/* SPDX-License-Identifier: GPL-2.0 */
/* Optimized version of the standard memset() function.
Copyright (c) 2002 Hewlett-Packard Co/CERN
Sverre Jarp <Sverre.Jarp@cern.ch>
Return: dest
Inputs:
in0: dest
in1: value
in2: count
The algorithm is fairly straightforward: set byte by byte until we
we get to a 16B-aligned address, then loop on 128 B chunks using an
early store as prefetching, then loop on 32B chucks, then clear remaining
words, finally clear remaining bytes.
Since a stf.spill f0 can store 16B in one go, we use this instruction
to get peak speed when value = 0. */
#include <asm/asmmacro.h>
#include <asm/export.h>
#undef ret
#define dest in0
#define value in1
#define cnt in2
#define tmp r31
#define save_lc r30
#define ptr0 r29
#define ptr1 r28
#define ptr2 r27
#define ptr3 r26
#define ptr9 r24
#define loopcnt r23
#define linecnt r22
#define bytecnt r21
#define fvalue f6
// This routine uses only scratch predicate registers (p6 - p15)
#define p_scr p6 // default register for same-cycle branches
#define p_nz p7
#define p_zr p8
#define p_unalgn p9
#define p_y p11
#define p_n p12
#define p_yy p13
#define p_nn p14
#define MIN1 15
#define MIN1P1HALF 8
#define LINE_SIZE 128
#define LSIZE_SH 7 // shift amount
#define PREF_AHEAD 8
GLOBAL_ENTRY(memset)
{ .mmi
.prologue
alloc tmp = ar.pfs, 3, 0, 0, 0
lfetch.nt1 [dest] //
.save ar.lc, save_lc
mov.i save_lc = ar.lc
.body
} { .mmi
mov ret0 = dest // return value
cmp.ne p_nz, p_zr = value, r0 // use stf.spill if value is zero
cmp.eq p_scr, p0 = cnt, r0
;; }
{ .mmi
and ptr2 = -(MIN1+1), dest // aligned address
and tmp = MIN1, dest // prepare to check for correct alignment
tbit.nz p_y, p_n = dest, 0 // Do we have an odd address? (M_B_U)
} { .mib
mov ptr1 = dest
mux1 value = value, @brcst // create 8 identical bytes in word
(p_scr) br.ret.dpnt.many rp // return immediately if count = 0
;; }
{ .mib
cmp.ne p_unalgn, p0 = tmp, r0 //
} { .mib
sub bytecnt = (MIN1+1), tmp // NB: # of bytes to move is 1 higher than loopcnt
cmp.gt p_scr, p0 = 16, cnt // is it a minimalistic task?
(p_scr) br.cond.dptk.many .move_bytes_unaligned // go move just a few (M_B_U)
;; }
{ .mmi
(p_unalgn) add ptr1 = (MIN1+1), ptr2 // after alignment
(p_unalgn) add ptr2 = MIN1P1HALF, ptr2 // after alignment
(p_unalgn) tbit.nz.unc p_y, p_n = bytecnt, 3 // should we do a st8 ?
;; }
{ .mib
(p_y) add cnt = -8, cnt //
(p_unalgn) tbit.nz.unc p_yy, p_nn = bytecnt, 2 // should we do a st4 ?
} { .mib
(p_y) st8 [ptr2] = value,-4 //
(p_n) add ptr2 = 4, ptr2 //
;; }
{ .mib
(p_yy) add cnt = -4, cnt //
(p_unalgn) tbit.nz.unc p_y, p_n = bytecnt, 1 // should we do a st2 ?
} { .mib
(p_yy) st4 [ptr2] = value,-2 //
(p_nn) add ptr2 = 2, ptr2 //
;; }
{ .mmi
mov tmp = LINE_SIZE+1 // for compare
(p_y) add cnt = -2, cnt //
(p_unalgn) tbit.nz.unc p_yy, p_nn = bytecnt, 0 // should we do a st1 ?
} { .mmi
setf.sig fvalue=value // transfer value to FLP side
(p_y) st2 [ptr2] = value,-1 //
(p_n) add ptr2 = 1, ptr2 //
;; }
{ .mmi
(p_yy) st1 [ptr2] = value //
cmp.gt p_scr, p0 = tmp, cnt // is it a minimalistic task?
} { .mbb
(p_yy) add cnt = -1, cnt //
(p_scr) br.cond.dpnt.many .fraction_of_line // go move just a few
;; }
{ .mib
nop.m 0
shr.u linecnt = cnt, LSIZE_SH
(p_zr) br.cond.dptk.many .l1b // Jump to use stf.spill
;; }
TEXT_ALIGN(32) // --------------------- // L1A: store ahead into cache lines; fill later
{ .mmi
and tmp = -(LINE_SIZE), cnt // compute end of range
mov ptr9 = ptr1 // used for prefetching
and cnt = (LINE_SIZE-1), cnt // remainder
} { .mmi
mov loopcnt = PREF_AHEAD-1 // default prefetch loop
cmp.gt p_scr, p0 = PREF_AHEAD, linecnt // check against actual value
;; }
{ .mmi
(p_scr) add loopcnt = -1, linecnt //
add ptr2 = 8, ptr1 // start of stores (beyond prefetch stores)
add ptr1 = tmp, ptr1 // first address beyond total range
;; }
{ .mmi
add tmp = -1, linecnt // next loop count
mov.i ar.lc = loopcnt //
;; }
.pref_l1a:
{ .mib
stf8 [ptr9] = fvalue, 128 // Do stores one cache line apart
nop.i 0
br.cloop.dptk.few .pref_l1a
;; }
{ .mmi
add ptr0 = 16, ptr2 // Two stores in parallel
mov.i ar.lc = tmp //
;; }
.l1ax:
{ .mmi
stf8 [ptr2] = fvalue, 8
stf8 [ptr0] = fvalue, 8
;; }
{ .mmi
stf8 [ptr2] = fvalue, 24
stf8 [ptr0] = fvalue, 24
;; }
{ .mmi
stf8 [ptr2] = fvalue, 8
stf8 [ptr0] = fvalue, 8
;; }
{ .mmi
stf8 [ptr2] = fvalue, 24
stf8 [ptr0] = fvalue, 24
;; }
{ .mmi
stf8 [ptr2] = fvalue, 8
stf8 [ptr0] = fvalue, 8
;; }
{ .mmi
stf8 [ptr2] = fvalue, 24
stf8 [ptr0] = fvalue, 24
;; }
{ .mmi
stf8 [ptr2] = fvalue, 8
stf8 [ptr0] = fvalue, 32
cmp.lt p_scr, p0 = ptr9, ptr1 // do we need more prefetching?
;; }
{ .mmb
stf8 [ptr2] = fvalue, 24
(p_scr) stf8 [ptr9] = fvalue, 128
br.cloop.dptk.few .l1ax
;; }
{ .mbb
cmp.le p_scr, p0 = 8, cnt // just a few bytes left ?
(p_scr) br.cond.dpnt.many .fraction_of_line // Branch no. 2
br.cond.dpnt.many .move_bytes_from_alignment // Branch no. 3
;; }
TEXT_ALIGN(32)
.l1b: // ------------------------------------ // L1B: store ahead into cache lines; fill later
{ .mmi
and tmp = -(LINE_SIZE), cnt // compute end of range
mov ptr9 = ptr1 // used for prefetching
and cnt = (LINE_SIZE-1), cnt // remainder
} { .mmi
mov loopcnt = PREF_AHEAD-1 // default prefetch loop
cmp.gt p_scr, p0 = PREF_AHEAD, linecnt // check against actual value
;; }
{ .mmi
(p_scr) add loopcnt = -1, linecnt
add ptr2 = 16, ptr1 // start of stores (beyond prefetch stores)
add ptr1 = tmp, ptr1 // first address beyond total range
;; }
{ .mmi
add tmp = -1, linecnt // next loop count
mov.i ar.lc = loopcnt
;; }
.pref_l1b:
{ .mib
stf.spill [ptr9] = f0, 128 // Do stores one cache line apart
nop.i 0
br.cloop.dptk.few .pref_l1b
;; }
{ .mmi
add ptr0 = 16, ptr2 // Two stores in parallel
mov.i ar.lc = tmp
;; }
.l1bx:
{ .mmi
stf.spill [ptr2] = f0, 32
stf.spill [ptr0] = f0, 32
;; }
{ .mmi
stf.spill [ptr2] = f0, 32
stf.spill [ptr0] = f0, 32
;; }
{ .mmi
stf.spill [ptr2] = f0, 32
stf.spill [ptr0] = f0, 64
cmp.lt p_scr, p0 = ptr9, ptr1 // do we need more prefetching?
;; }
{ .mmb
stf.spill [ptr2] = f0, 32
(p_scr) stf.spill [ptr9] = f0, 128
br.cloop.dptk.few .l1bx
;; }
{ .mib
cmp.gt p_scr, p0 = 8, cnt // just a few bytes left ?
(p_scr) br.cond.dpnt.many .move_bytes_from_alignment //
;; }
.fraction_of_line:
{ .mib
add ptr2 = 16, ptr1
shr.u loopcnt = cnt, 5 // loopcnt = cnt / 32
;; }
{ .mib
cmp.eq p_scr, p0 = loopcnt, r0
add loopcnt = -1, loopcnt
(p_scr) br.cond.dpnt.many .store_words
;; }
{ .mib
and cnt = 0x1f, cnt // compute the remaining cnt
mov.i ar.lc = loopcnt
;; }
TEXT_ALIGN(32)
.l2: // ------------------------------------ // L2A: store 32B in 2 cycles
{ .mmb
stf8 [ptr1] = fvalue, 8
stf8 [ptr2] = fvalue, 8
;; } { .mmb
stf8 [ptr1] = fvalue, 24
stf8 [ptr2] = fvalue, 24
br.cloop.dptk.many .l2
;; }
.store_words:
{ .mib
cmp.gt p_scr, p0 = 8, cnt // just a few bytes left ?
(p_scr) br.cond.dpnt.many .move_bytes_from_alignment // Branch
;; }
{ .mmi
stf8 [ptr1] = fvalue, 8 // store
cmp.le p_y, p_n = 16, cnt
add cnt = -8, cnt // subtract
;; }
{ .mmi
(p_y) stf8 [ptr1] = fvalue, 8 // store
(p_y) cmp.le.unc p_yy, p_nn = 16, cnt
(p_y) add cnt = -8, cnt // subtract
;; }
{ .mmi // store
(p_yy) stf8 [ptr1] = fvalue, 8
(p_yy) add cnt = -8, cnt // subtract
;; }
.move_bytes_from_alignment:
{ .mib
cmp.eq p_scr, p0 = cnt, r0
tbit.nz.unc p_y, p0 = cnt, 2 // should we terminate with a st4 ?
(p_scr) br.cond.dpnt.few .restore_and_exit
;; }
{ .mib
(p_y) st4 [ptr1] = value,4
tbit.nz.unc p_yy, p0 = cnt, 1 // should we terminate with a st2 ?
;; }
{ .mib
(p_yy) st2 [ptr1] = value,2
tbit.nz.unc p_y, p0 = cnt, 0 // should we terminate with a st1 ?
;; }
{ .mib
(p_y) st1 [ptr1] = value
;; }
.restore_and_exit:
{ .mib
nop.m 0
mov.i ar.lc = save_lc
br.ret.sptk.many rp
;; }
.move_bytes_unaligned:
{ .mmi
.pred.rel "mutex",p_y, p_n
.pred.rel "mutex",p_yy, p_nn
(p_n) cmp.le p_yy, p_nn = 4, cnt
(p_y) cmp.le p_yy, p_nn = 5, cnt
(p_n) add ptr2 = 2, ptr1
} { .mmi
(p_y) add ptr2 = 3, ptr1
(p_y) st1 [ptr1] = value, 1 // fill 1 (odd-aligned) byte [15, 14 (or less) left]
(p_y) add cnt = -1, cnt
;; }
{ .mmi
(p_yy) cmp.le.unc p_y, p0 = 8, cnt
add ptr3 = ptr1, cnt // prepare last store
mov.i ar.lc = save_lc
} { .mmi
(p_yy) st2 [ptr1] = value, 4 // fill 2 (aligned) bytes
(p_yy) st2 [ptr2] = value, 4 // fill 2 (aligned) bytes [11, 10 (o less) left]
(p_yy) add cnt = -4, cnt
;; }
{ .mmi
(p_y) cmp.le.unc p_yy, p0 = 8, cnt
add ptr3 = -1, ptr3 // last store
tbit.nz p_scr, p0 = cnt, 1 // will there be a st2 at the end ?
} { .mmi
(p_y) st2 [ptr1] = value, 4 // fill 2 (aligned) bytes
(p_y) st2 [ptr2] = value, 4 // fill 2 (aligned) bytes [7, 6 (or less) left]
(p_y) add cnt = -4, cnt
;; }
{ .mmi
(p_yy) st2 [ptr1] = value, 4 // fill 2 (aligned) bytes
(p_yy) st2 [ptr2] = value, 4 // fill 2 (aligned) bytes [3, 2 (or less) left]
tbit.nz p_y, p0 = cnt, 0 // will there be a st1 at the end ?
} { .mmi
(p_yy) add cnt = -4, cnt
;; }
{ .mmb
(p_scr) st2 [ptr1] = value // fill 2 (aligned) bytes
(p_y) st1 [ptr3] = value // fill last byte (using ptr3)
br.ret.sptk.many rp
}
END(memset)
EXPORT_SYMBOL(memset)
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