diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2017-06-13 23:05:48 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-06-19 19:46:27 +1000 |
| commit | a9af97aa0a12c30178dd7ad9af8887d5b9c4647b (patch) | |
| tree | 463875705ded254aebad36ee4347c5eeba5b0846 /arch/powerpc/kernel/exceptions-64s.S | |
| parent | 771d4304d07f080b6ce751e12f3579cb012a1b22 (diff) | |
powerpc/64s: msgclr when handling doorbell exceptions from system reset
msgsnd doorbell exceptions are cleared when the doorbell interrupt is
taken. However if a doorbell exception causes a system reset interrupt
wake from power saving state, the message is not cleared. Processing
the doorbell from the system reset interrupt requires msgclr to avoid
taking the exception again.
Testing this plus the previous wakup direct patch gives:
original wakeup direct msgclr
Different threads, same core: 315k/s 264k/s 345k/s
Different cores: 235k/s 242k/s 242k/s
Net speedup is +10% for same core, and +3% for different core.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 2f700a15bfa3..1752beefee69 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1612,6 +1612,25 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) b 1b /* + * When doorbell is triggered from system reset wakeup, the message is + * not cleared, so it would fire again when EE is enabled. + * + * When coming from local_irq_enable, there may be the same problem if + * we were hard disabled. + * + * Execute msgclr to clear pending exceptions before handling it. + */ +h_doorbell_common_msgclr: + LOAD_REG_IMMEDIATE(r3, PPC_DBELL_MSGTYPE << (63-36)) + PPC_MSGCLR(3) + b h_doorbell_common + +doorbell_super_common_msgclr: + LOAD_REG_IMMEDIATE(r3, PPC_DBELL_MSGTYPE << (63-36)) + PPC_MSGCLRP(3) + b doorbell_super_common + +/* * Called from arch_local_irq_enable when an interrupt needs * to be resent. r3 contains 0x500, 0x900, 0xa00 or 0xe80 to indicate * which kind of interrupt. MSR:EE is already off. We generate a @@ -1636,13 +1655,13 @@ _GLOBAL(__replay_interrupt) beq hardware_interrupt_common BEGIN_FTR_SECTION cmpwi r3,0xe80 - beq h_doorbell_common + beq h_doorbell_common_msgclr cmpwi r3,0xea0 beq h_virt_irq_common cmpwi r3,0xe60 beq hmi_exception_common FTR_SECTION_ELSE cmpwi r3,0xa00 - beq doorbell_super_common + beq doorbell_super_common_msgclr ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) blr |