History log of /linux-master/arch/m68k/include/asm/div64.h
Revision Date Author Comments
# 668a9202 09-Aug-2023 Arnd Bergmann <arnd@arndb.de>

m68k: Define __div64_32() to avoid a warning

The generic __div64_32() definition is built on all architectures that
don't provide this as a macro. m68k however neither defines nor
requires __div64_32, so it should define an empty one to avoid the
warning:

lib/math/div64.c:31:32: error: no previous prototype for '__div64_32' [-Werror=missing-prototypes]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20230809211057.60514-1-arnd@kernel.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>


# b2441318 01-Nov-2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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>


# ea077b1b 09-Aug-2013 Andreas Schwab <schwab@linux-m68k.org>

m68k: Truncate base in do_div()

Explicitly truncate the second operand of do_div() to 32 bits to guard
against bogus code calling it with a 64-bit divisor.

[Thorsten]

After upgrading from 3.2 to 3.10, mounting a btrfs volume fails with:

btrfs: setting nodatacow, compression disabled
btrfs: enabling auto recovery
btrfs: disk space caching is enabled
*** ZERO DIVIDE *** FORMAT=2
Current process id is 722
BAD KERNEL TRAP: 00000000
Modules linked in: evdev mac_hid ext4 crc16 jbd2 mbcache btrfs xor lzo_compress zlib_deflate raid6_pq crc32c libcrc32c
PC: [<319535b2>] __btrfs_map_block+0x11c/0x119a [btrfs]
SR: 2000 SP: 30c1fab4 a2: 30f0faf0
d0: 00000000 d1: 00001000 d2: 00000000 d3: 00000000
d4: 00010000 d5: 00000000 a0: 3085c72c a1: 3085c72c
Process mount (pid: 722, task=30f0faf0)
Frame format=2 instr addr=319535ae
Stack from 30c1faec:
00000000 00000020 00000000 00001000 00000000 01401000 30253928 300ffc00
00a843ac 3026f640 00000000 00010000 0009e250 00d106c0 00011220 00000000
00001000 301c6830 0009e32a 000000ff 00000009 3085c72c 00000000 00000000
30c1fd14 00000000 00000020 00000000 30c1fd14 0009e26c 00000020 00000003
00000000 0009dd8a 300b0b6c 30253928 00a843ac 00001000 00000000 00000000
0000a008 3194e76a 30253928 00a843ac 00001000 00000000 00000000 00000002
Call Trace: [<00001000>] kernel_pg_dir+0x0/0x1000

[...]

Code: 222e ff74 2a2e ff5c 2c2e ff60 4c45 1402 <2d40> ff64 2d41 ff68 2205 4c2e 1800 ff68 4c04 0800 2041 d1c0 2206 4c2e 1400 ff68

[Geert]

As diagnosed by Andreas, fs/btrfs/volumes.c:__btrfs_map_block()
calls

do_div(stripe_nr, stripe_len);

with stripe_len u64, while do_div() assumes the divisor is a 32-bit number.

Due to the lack of truncation in the m68k-specific implementation of
do_div(), the division is performed using the upper 32-bit word of
stripe_len, which is zero.

This was introduced by commit 53b381b3abeb86f12787a6c40fee9b2f71edc23b
("Btrfs: RAID5 and RAID6"), which changed the divisor from
map->stripe_len (struct map_lookup.stripe_len is int) to a 64-bit temporary.

Reported-by: Thorsten Glaser <tg@debian.org>
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Tested-by: Thorsten Glaser <tg@debian.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org


# 84f3fb7a 10-Nov-2011 Greg Ungerer <gerg@uclinux.org>

m68k: handle presence of 64bit mul/div instructions cleanly

The traditional 68000 processors and the newer reduced instruction set
ColdFire processors do not support the 32*32->64 multiply or the 64/32->32
divide instructions. This is not a difference based on the presence of
a hardware MMU or not.

Create a new config symbol to mark that a CPU type doesn't support the
longer multiply/divide instructions. Use this then as a basis for using
the fast 64bit based divide (in div64.h) and for linking in the extra
libgcc functions that may be required (mulsi3, divsi3, etc).

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>


# d20f5aa3 05-Feb-2009 Greg Ungerer <gerg@uclinux.org>

m68k: merge the mmu and non-mmu versions of div64.h

Trivial merge of the mmu and non-mmu versions of div64.h

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>


# 49148020 16-Jan-2009 Sam Ravnborg <sam@ravnborg.org>

m68k,m68knommu: merge header files

Merge header files for m68k and m68knommu to the single location:

arch/m68k/include/asm

The majority of this patch was the result of the
script that is included in the changelog below.

The script was originally written by Arnd Bergman and
exten by me to cover a few more files.

When the header files differed the script uses the following:

The original m68k file is named <file>_mm.h [mm for memory manager]
The m68knommu file is named <file>_no.h [no for no memory manager]

The files uses the following include guard:

This include gaurd works as the m68knommu toolchain set
the __uClinux__ symbol - so this should work in userspace too.

Merging the header files for m68k and m68knommu exposes the
(unexpected?) ABI differences thus it is easier to actually
identify these and thus to fix them.

The commit has been build tested with both a m68k and
a m68knommu toolchain - with success.

The commit has also been tested with "make headers_check"
and this patch fixes make headers_check for m68knommu.

The script used:
TARGET=arch/m68k/include/asm
SOURCE=arch/m68knommu/include/asm

INCLUDE="cachectl.h errno.h fcntl.h hwtest.h ioctls.h ipcbuf.h \
linkage.h math-emu.h md.h mman.h movs.h msgbuf.h openprom.h \
oplib.h poll.h posix_types.h resource.h rtc.h sembuf.h shmbuf.h \
shm.h shmparam.h socket.h sockios.h spinlock.h statfs.h stat.h \
termbits.h termios.h tlb.h types.h user.h"

EQUAL="auxvec.h cputime.h device.h emergency-restart.h futex.h \
ioctl.h irq_regs.h kdebug.h local.h mutex.h percpu.h \
sections.h topology.h"

NOMUUFILES="anchor.h bootstd.h coldfire.h commproc.h dbg.h \
elia.h flat.h m5206sim.h m520xsim.h m523xsim.h m5249sim.h \
m5272sim.h m527xsim.h m528xsim.h m5307sim.h m532xsim.h \
m5407sim.h m68360_enet.h m68360.h m68360_pram.h m68360_quicc.h \
m68360_regs.h MC68328.h MC68332.h MC68EZ328.h MC68VZ328.h \
mcfcache.h mcfdma.h mcfmbus.h mcfne.h mcfpci.h mcfpit.h \
mcfsim.h mcfsmc.h mcftimer.h mcfuart.h mcfwdebug.h \
nettel.h quicc_simple.h smp.h"

FILES="atomic.h bitops.h bootinfo.h bug.h bugs.h byteorder.h cache.h \
cacheflush.h checksum.h current.h delay.h div64.h \
dma-mapping.h dma.h elf.h entry.h fb.h fpu.h hardirq.h hw_irq.h io.h \
irq.h kmap_types.h machdep.h mc146818rtc.h mmu.h mmu_context.h \
module.h page.h page_offset.h param.h pci.h pgalloc.h \
pgtable.h processor.h ptrace.h scatterlist.h segment.h \
setup.h sigcontext.h siginfo.h signal.h string.h system.h swab.h \
thread_info.h timex.h tlbflush.h traps.h uaccess.h ucontext.h \
unaligned.h unistd.h"

mergefile() {
BASE=${1%.h}
git mv ${SOURCE}/$1 ${TARGET}/${BASE}_no.h
git mv ${TARGET}/$1 ${TARGET}/${BASE}_mm.h

cat << EOF > ${TARGET}/$1
EOF

git add ${TARGET}/$1
}

set -e

mkdir -p ${TARGET}

git mv include/asm-m68k/* ${TARGET}
rmdir include/asm-m68k

git rm ${SOURCE}/Kbuild
for F in $INCLUDE $EQUAL; do
git rm ${SOURCE}/$F
done

for F in $NOMUUFILES; do
git mv ${SOURCE}/$F ${TARGET}/$F
done

for F in $FILES ; do
mergefile $F
done

rmdir arch/m68knommu/include/asm
rmdir arch/m68knommu/include

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>