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| author | Nicholas Piggin <npiggin@gmail.com> | 2018-05-10 22:21:48 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-06-03 20:40:30 +1000 |
| commit | ee03b9b4479d1302d01cebedda3518dc967697b7 (patch) | |
| tree | 9386d5d153273203946726d7ee5d07a382fe7e2b /arch/powerpc/platforms | |
| parent | 3130a7bb6eb595f2d963976a4d3e57db77bcf06f (diff) | |
| download | op-kernel-dev-ee03b9b4479d1302d01cebedda3518dc967697b7.zip op-kernel-dev-ee03b9b4479d1302d01cebedda3518dc967697b7.tar.gz | |
powerpc/powernv: call OPAL_QUIESCE before OPAL_SIGNAL_SYSTEM_RESET
Although it is often possible to recover a CPU that was interrupted
from OPAL with a system reset NMI, it's undesirable to interrupt them
for a few reasons. Firstly because dump/debug code itself needs to
call firmware, so it could hang on a lock or possibly corrupt a
per-cpu data structure if it or another CPU was interrupted from
OPAL. Secondly, the kexec crash dump code will not return from
interrupt to unwind the OPAL call.
Call OPAL_QUIESCE with QUIESCE_HOLD before sending an NMI IPI to
another CPU, which wait for it to leave firmware (or time out) to
avoid this problem in normal conditions. Firmware bugs may still
result in a timeout and interrupting OPAL, but that is the best
option (stops the CPU, and possibly allows firmware to be debugged).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/platforms')
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal-wrappers.S | 1 | ||||
| -rw-r--r-- | arch/powerpc/platforms/powernv/smp.c | 17 |
2 files changed, 17 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S index 8482df2..a8d9b40 100644 --- a/arch/powerpc/platforms/powernv/opal-wrappers.S +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S @@ -320,6 +320,7 @@ OPAL_CALL(opal_set_powercap, OPAL_SET_POWERCAP); OPAL_CALL(opal_get_power_shift_ratio, OPAL_GET_POWER_SHIFT_RATIO); OPAL_CALL(opal_set_power_shift_ratio, OPAL_SET_POWER_SHIFT_RATIO); OPAL_CALL(opal_sensor_group_clear, OPAL_SENSOR_GROUP_CLEAR); +OPAL_CALL(opal_quiesce, OPAL_QUIESCE); OPAL_CALL(opal_npu_spa_setup, OPAL_NPU_SPA_SETUP); OPAL_CALL(opal_npu_spa_clear_cache, OPAL_NPU_SPA_CLEAR_CACHE); OPAL_CALL(opal_npu_tl_set, OPAL_NPU_TL_SET); diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c index 19af6de..b809099 100644 --- a/arch/powerpc/platforms/powernv/smp.c +++ b/arch/powerpc/platforms/powernv/smp.c @@ -334,7 +334,16 @@ static int pnv_cause_nmi_ipi(int cpu) int64_t rc; if (cpu >= 0) { - rc = opal_signal_system_reset(get_hard_smp_processor_id(cpu)); + int h = get_hard_smp_processor_id(cpu); + + if (opal_check_token(OPAL_QUIESCE)) + opal_quiesce(QUIESCE_HOLD, h); + + rc = opal_signal_system_reset(h); + + if (opal_check_token(OPAL_QUIESCE)) + opal_quiesce(QUIESCE_RESUME, h); + if (rc != OPAL_SUCCESS) return 0; return 1; @@ -343,6 +352,8 @@ static int pnv_cause_nmi_ipi(int cpu) bool success = true; int c; + if (opal_check_token(OPAL_QUIESCE)) + opal_quiesce(QUIESCE_HOLD, -1); /* * We do not use broadcasts (yet), because it's not clear @@ -358,6 +369,10 @@ static int pnv_cause_nmi_ipi(int cpu) if (rc != OPAL_SUCCESS) success = false; } + + if (opal_check_token(OPAL_QUIESCE)) + opal_quiesce(QUIESCE_RESUME, -1); + if (success) return 1; |
