Linux/M68K currently doesn't support robust futexes or PI mutexes.
The problem is that the futex code needs to perform certain ops
(cmpxchg, set, add, or, andn, xor) atomically on user-space
addresses, and M68K's lack of a futex.h causes those operations
to be unsupported and disabled.
This patch adds that support, but only for uniprocessor machines,
which is adequate for M68K. For UP it's enough to disable preemption
to ensure mutual exclusion (futexes don't need to care about other
hardware agents), and the mandatory pagefault_disable() does just that.
This patch is closely based on the one I co-wrote for UP ARM back
in August 2008. The main change is that this patch uses the C
get_user/put_user accessors instead of inline assembly code with
exception table fixups.
For non-MMU machines the new futex.h simply redirects to the generic
futex.h, so there is no functional change for them.
Tested on aranym with the glibc-2.17 test suite: no regressions, and
a number of mutex/condvar test cases went from failing to succeeding
(tst-mutexpi{5,5a,6,9}, tst-cond2[45], tst-robust[1-9], tst-robustpi[1-8]).
Also tested with glibc-2.18 HEAD and a local glibc patch to enable PI
mutexes: no regressions.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Acked-by: Andreas Schwab <schwab@linux-m68k.org>
[geert: Added removal of ""generic-y += futex.h"]
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
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>
