linux/arch/sh/lib64/copy_user_memcpy.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

219 lines
5.2 KiB
ArmAsm

! SPDX-License-Identifier: GPL-2.0
!
! Fast SH memcpy
!
! by Toshiyasu Morita (tm@netcom.com)
! hacked by J"orn Rernnecke (joern.rennecke@superh.com) ("o for o-umlaut)
! SH5 code Copyright 2002 SuperH Ltd.
!
! Entry: ARG0: destination pointer
! ARG1: source pointer
! ARG2: byte count
!
! Exit: RESULT: destination pointer
! any other registers in the range r0-r7: trashed
!
! Notes: Usually one wants to do small reads and write a longword, but
! unfortunately it is difficult in some cases to concatanate bytes
! into a longword on the SH, so this does a longword read and small
! writes.
!
! This implementation makes two assumptions about how it is called:
!
! 1.: If the byte count is nonzero, the address of the last byte to be
! copied is unsigned greater than the address of the first byte to
! be copied. This could be easily swapped for a signed comparison,
! but the algorithm used needs some comparison.
!
! 2.: When there are two or three bytes in the last word of an 11-or-more
! bytes memory chunk to b copied, the rest of the word can be read
! without side effects.
! This could be easily changed by increasing the minimum size of
! a fast memcpy and the amount subtracted from r7 before L_2l_loop be 2,
! however, this would cost a few extra cyles on average.
! For SHmedia, the assumption is that any quadword can be read in its
! enirety if at least one byte is included in the copy.
/* Imported into Linux kernel by Richard Curnow. This is used to implement the
__copy_user function in the general case, so it has to be a distinct
function from intra-kernel memcpy to allow for exception fix-ups in the
event that the user pointer is bad somewhere in the copy (e.g. due to
running off the end of the vma).
Note, this algorithm will be slightly wasteful in the case where the source
and destination pointers are equally aligned, because the stlo/sthi pairs
could then be merged back into single stores. If there are a lot of cache
misses, this is probably offset by the stall lengths on the preloads.
*/
/* NOTE : Prefetches removed and allocos guarded by synco to avoid TAKum03020
* erratum. The first two prefetches are nop-ed out to avoid upsetting the
* instruction counts used in the jump address calculation.
* */
.section .text..SHmedia32,"ax"
.little
.balign 32
.global copy_user_memcpy
.global copy_user_memcpy_end
copy_user_memcpy:
#define LDUAQ(P,O,D0,D1) ldlo.q P,O,D0; ldhi.q P,O+7,D1
#define STUAQ(P,O,D0,D1) stlo.q P,O,D0; sthi.q P,O+7,D1
#define LDUAL(P,O,D0,D1) ldlo.l P,O,D0; ldhi.l P,O+3,D1
#define STUAL(P,O,D0,D1) stlo.l P,O,D0; sthi.l P,O+3,D1
nop ! ld.b r3,0,r63 ! TAKum03020
pta/l Large,tr0
movi 25,r0
bgeu/u r4,r0,tr0
nsb r4,r0
shlli r0,5,r0
movi (L1-L0+63*32 + 1) & 0xffff,r1
sub r1, r0, r0
L0: ptrel r0,tr0
add r2,r4,r5
ptabs r18,tr1
add r3,r4,r6
blink tr0,r63
/* Rearranged to make cut2 safe */
.balign 8
L4_7: /* 4..7 byte memcpy cntd. */
stlo.l r2, 0, r0
or r6, r7, r6
sthi.l r5, -1, r6
stlo.l r5, -4, r6
blink tr1,r63
.balign 8
L1: /* 0 byte memcpy */
nop
blink tr1,r63
nop
nop
nop
nop
L2_3: /* 2 or 3 byte memcpy cntd. */
st.b r5,-1,r6
blink tr1,r63
/* 1 byte memcpy */
ld.b r3,0,r0
st.b r2,0,r0
blink tr1,r63
L8_15: /* 8..15 byte memcpy cntd. */
stlo.q r2, 0, r0
or r6, r7, r6
sthi.q r5, -1, r6
stlo.q r5, -8, r6
blink tr1,r63
/* 2 or 3 byte memcpy */
ld.b r3,0,r0
nop ! ld.b r2,0,r63 ! TAKum03020
ld.b r3,1,r1
st.b r2,0,r0
pta/l L2_3,tr0
ld.b r6,-1,r6
st.b r2,1,r1
blink tr0, r63
/* 4 .. 7 byte memcpy */
LDUAL (r3, 0, r0, r1)
pta L4_7, tr0
ldlo.l r6, -4, r7
or r0, r1, r0
sthi.l r2, 3, r0
ldhi.l r6, -1, r6
blink tr0, r63
/* 8 .. 15 byte memcpy */
LDUAQ (r3, 0, r0, r1)
pta L8_15, tr0
ldlo.q r6, -8, r7
or r0, r1, r0
sthi.q r2, 7, r0
ldhi.q r6, -1, r6
blink tr0, r63
/* 16 .. 24 byte memcpy */
LDUAQ (r3, 0, r0, r1)
LDUAQ (r3, 8, r8, r9)
or r0, r1, r0
sthi.q r2, 7, r0
or r8, r9, r8
sthi.q r2, 15, r8
ldlo.q r6, -8, r7
ldhi.q r6, -1, r6
stlo.q r2, 8, r8
stlo.q r2, 0, r0
or r6, r7, r6
sthi.q r5, -1, r6
stlo.q r5, -8, r6
blink tr1,r63
Large:
! ld.b r2, 0, r63 ! TAKum03020
pta/l Loop_ua, tr1
ori r3, -8, r7
sub r2, r7, r22
sub r3, r2, r6
add r2, r4, r5
ldlo.q r3, 0, r0
addi r5, -16, r5
movi 64+8, r27 ! could subtract r7 from that.
stlo.q r2, 0, r0
sthi.q r2, 7, r0
ldx.q r22, r6, r0
bgtu/l r27, r4, tr1
addi r5, -48, r27
pta/l Loop_line, tr0
addi r6, 64, r36
addi r6, -24, r19
addi r6, -16, r20
addi r6, -8, r21
Loop_line:
! ldx.q r22, r36, r63 ! TAKum03020
alloco r22, 32
synco
addi r22, 32, r22
ldx.q r22, r19, r23
sthi.q r22, -25, r0
ldx.q r22, r20, r24
ldx.q r22, r21, r25
stlo.q r22, -32, r0
ldx.q r22, r6, r0
sthi.q r22, -17, r23
sthi.q r22, -9, r24
sthi.q r22, -1, r25
stlo.q r22, -24, r23
stlo.q r22, -16, r24
stlo.q r22, -8, r25
bgeu r27, r22, tr0
Loop_ua:
addi r22, 8, r22
sthi.q r22, -1, r0
stlo.q r22, -8, r0
ldx.q r22, r6, r0
bgtu/l r5, r22, tr1
add r3, r4, r7
ldlo.q r7, -8, r1
sthi.q r22, 7, r0
ldhi.q r7, -1, r7
ptabs r18,tr1
stlo.q r22, 0, r0
or r1, r7, r1
sthi.q r5, 15, r1
stlo.q r5, 8, r1
blink tr1, r63
copy_user_memcpy_end:
nop