linux/tools/testing/selftests/powerpc/tm/Makefile

TEST_PROGS := tm-resched-dscr tm-syscall

all: $(TEST_PROGS)

$(TEST_PROGS): ../harness.c

tm-syscall: tm-syscall-asm.S
tm-syscall: CFLAGS += -mhtm -I../../../../../usr/include

include ../../lib.mk

clean:
	rm -f $(TEST_PROGS) *.o
powerpc/tm: Abort syscalls in active transactions This patch changes the syscall handler to doom (tabort) active transactions when a syscall is made and return very early without performing the syscall and keeping side effects to a minimum (no CPU accounting or system call tracing is performed). Also included is a new HWCAP2 bit, PPC_FEATURE2_HTM_NOSC, to indicate this behaviour to userspace. Currently, the system call instruction automatically suspends an active transaction which causes side effects to persist when an active transaction fails. This does change the kernel's behaviour, but in a way that was documented as unsupported. It doesn't reduce functionality as syscalls will still be performed after tsuspend; it just requires that the transaction be explicitly suspended. It also provides a consistent interface and makes the behaviour of user code substantially the same across powerpc and platforms that do not support suspended transactions (e.g. x86 and s390). Performance measurements using http://ozlabs.org/~anton/junkcode/null_syscall.c indicate the cost of a normal (non-aborted) system call increases by about 0.25%. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 2015-06-12 01:06:32 +00:00			`TEST_PROGS := tm-resched-dscr tm-syscall`
powerpc: Correct DSCR during TM context switch Correct the DSCR SPR becoming temporarily corrupted if a task is context switched during a transaction. The problem occurs while suspending the task and is caused by saving the DSCR to thread.dscr after it has already been set to the CPU's default value: __switch_to() calls __switch_to_tm() which calls tm_reclaim_task() which calls tm_reclaim_thread() which calls tm_reclaim() where the DSCR is set to the CPU's default __switch_to() calls _switch() where thread.dscr is set to the DSCR When the task is resumed, it's transaction will be doomed (as usual) and the DSCR SPR will be corrupted, although the checkpointed value will be correct. Therefore the DSCR will be immediately corrected by the transaction aborting, unless it has been suspended. In that case the incorrect value can be seen by the task until it resumes the transaction. The fix is to treat the DSCR similarly to the TAR and save it early in __switch_to(). A program exposing the problem is added to the kernel self tests as: tools/testing/selftests/powerpc/tm/tm-resched-dscr. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> CC: <stable@vger.kernel.org> [v3.10+] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> 2014-06-05 06:19:22 +00:00
selftests: Add install support for the powerpc tests The bulk of the selftests are actually below the powerpc sub directory. This adds support for installing them, when on a powerpc machine, or if ARCH and CROSS_COMPILE are set appropriately. This is a little more complicated because of the sub directory structure under powerpc, but much of the common logic in lib.mk is still used. The net effect of the patch is still a reduction in code. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> 2015-03-11 04:06:01 +00:00			`all: $(TEST_PROGS)`
powerpc: Correct DSCR during TM context switch Correct the DSCR SPR becoming temporarily corrupted if a task is context switched during a transaction. The problem occurs while suspending the task and is caused by saving the DSCR to thread.dscr after it has already been set to the CPU's default value: __switch_to() calls __switch_to_tm() which calls tm_reclaim_task() which calls tm_reclaim_thread() which calls tm_reclaim() where the DSCR is set to the CPU's default __switch_to() calls _switch() where thread.dscr is set to the DSCR When the task is resumed, it's transaction will be doomed (as usual) and the DSCR SPR will be corrupted, although the checkpointed value will be correct. Therefore the DSCR will be immediately corrected by the transaction aborting, unless it has been suspended. In that case the incorrect value can be seen by the task until it resumes the transaction. The fix is to treat the DSCR similarly to the TAR and save it early in __switch_to(). A program exposing the problem is added to the kernel self tests as: tools/testing/selftests/powerpc/tm/tm-resched-dscr. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> CC: <stable@vger.kernel.org> [v3.10+] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> 2014-06-05 06:19:22 +00:00
selftests: Add install support for the powerpc tests The bulk of the selftests are actually below the powerpc sub directory. This adds support for installing them, when on a powerpc machine, or if ARCH and CROSS_COMPILE are set appropriately. This is a little more complicated because of the sub directory structure under powerpc, but much of the common logic in lib.mk is still used. The net effect of the patch is still a reduction in code. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> 2015-03-11 04:06:01 +00:00			`$(TEST_PROGS): ../harness.c`
powerpc: Correct DSCR during TM context switch Correct the DSCR SPR becoming temporarily corrupted if a task is context switched during a transaction. The problem occurs while suspending the task and is caused by saving the DSCR to thread.dscr after it has already been set to the CPU's default value: __switch_to() calls __switch_to_tm() which calls tm_reclaim_task() which calls tm_reclaim_thread() which calls tm_reclaim() where the DSCR is set to the CPU's default __switch_to() calls _switch() where thread.dscr is set to the DSCR When the task is resumed, it's transaction will be doomed (as usual) and the DSCR SPR will be corrupted, although the checkpointed value will be correct. Therefore the DSCR will be immediately corrected by the transaction aborting, unless it has been suspended. In that case the incorrect value can be seen by the task until it resumes the transaction. The fix is to treat the DSCR similarly to the TAR and save it early in __switch_to(). A program exposing the problem is added to the kernel self tests as: tools/testing/selftests/powerpc/tm/tm-resched-dscr. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> CC: <stable@vger.kernel.org> [v3.10+] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> 2014-06-05 06:19:22 +00:00
selftests/powerpc: Add transactional syscall test Check that a syscall made during an active transaction will fail with the correct failure code and that one made during a suspended transaction will succeed. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 2015-04-10 04:16:49 +00:00			`tm-syscall: tm-syscall-asm.S`
powerpc/tm: Abort syscalls in active transactions This patch changes the syscall handler to doom (tabort) active transactions when a syscall is made and return very early without performing the syscall and keeping side effects to a minimum (no CPU accounting or system call tracing is performed). Also included is a new HWCAP2 bit, PPC_FEATURE2_HTM_NOSC, to indicate this behaviour to userspace. Currently, the system call instruction automatically suspends an active transaction which causes side effects to persist when an active transaction fails. This does change the kernel's behaviour, but in a way that was documented as unsupported. It doesn't reduce functionality as syscalls will still be performed after tsuspend; it just requires that the transaction be explicitly suspended. It also provides a consistent interface and makes the behaviour of user code substantially the same across powerpc and platforms that do not support suspended transactions (e.g. x86 and s390). Performance measurements using http://ozlabs.org/~anton/junkcode/null_syscall.c indicate the cost of a normal (non-aborted) system call increases by about 0.25%. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 2015-06-12 01:06:32 +00:00			`tm-syscall: CFLAGS += -mhtm -I../../../../../usr/include`
selftests/powerpc: Add transactional syscall test Check that a syscall made during an active transaction will fail with the correct failure code and that one made during a suspended transaction will succeed. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 2015-04-10 04:16:49 +00:00
selftests: Add install support for the powerpc tests The bulk of the selftests are actually below the powerpc sub directory. This adds support for installing them, when on a powerpc machine, or if ARCH and CROSS_COMPILE are set appropriately. This is a little more complicated because of the sub directory structure under powerpc, but much of the common logic in lib.mk is still used. The net effect of the patch is still a reduction in code. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> 2015-03-11 04:06:01 +00:00			`include ../../lib.mk`
powerpc: Correct DSCR during TM context switch Correct the DSCR SPR becoming temporarily corrupted if a task is context switched during a transaction. The problem occurs while suspending the task and is caused by saving the DSCR to thread.dscr after it has already been set to the CPU's default value: __switch_to() calls __switch_to_tm() which calls tm_reclaim_task() which calls tm_reclaim_thread() which calls tm_reclaim() where the DSCR is set to the CPU's default __switch_to() calls _switch() where thread.dscr is set to the DSCR When the task is resumed, it's transaction will be doomed (as usual) and the DSCR SPR will be corrupted, although the checkpointed value will be correct. Therefore the DSCR will be immediately corrected by the transaction aborting, unless it has been suspended. In that case the incorrect value can be seen by the task until it resumes the transaction. The fix is to treat the DSCR similarly to the TAR and save it early in __switch_to(). A program exposing the problem is added to the kernel self tests as: tools/testing/selftests/powerpc/tm/tm-resched-dscr. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> CC: <stable@vger.kernel.org> [v3.10+] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> 2014-06-05 06:19:22 +00:00
			`clean:`
selftests: Add install support for the powerpc tests The bulk of the selftests are actually below the powerpc sub directory. This adds support for installing them, when on a powerpc machine, or if ARCH and CROSS_COMPILE are set appropriately. This is a little more complicated because of the sub directory structure under powerpc, but much of the common logic in lib.mk is still used. The net effect of the patch is still a reduction in code. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> 2015-03-11 04:06:01 +00:00			`rm -f $(TEST_PROGS) *.o`