[PATCH v4 08/12] powerpc: Add support to mask perf interrupts and replay them
From: Madhavan Srinivasan <hidden>
Date: 2016-12-19 08:07:48
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
New bit mask field "IRQ_DISABLE_MASK_PMU" is introduced to support the masking of PMI. Couple of new irq #defs "PACA_IRQ_PMI" and "SOFTEN_VALUE_0xf0*" added to use in the exception code to check for PMI interrupts. In the masked_interrupt handler, for PMIs we reset the MSR[EE] and return. In the __check_irq_replay(), replay the PMI interrupt by calling performance_monitor_common handler. Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Madhavan Srinivasan <redacted> --- arch/powerpc/include/asm/exception-64s.h | 5 +++++ arch/powerpc/include/asm/hw_irq.h | 2 ++ arch/powerpc/kernel/entry_64.S | 5 +++++ arch/powerpc/kernel/exceptions-64s.S | 6 ++++-- arch/powerpc/kernel/irq.c | 25 ++++++++++++++++++++++++- 5 files changed, 40 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index cf01b440ebb6..c8531bc67bb0 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h@@ -431,6 +431,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) #define SOFTEN_VALUE_0xe80 PACA_IRQ_DBELL #define SOFTEN_VALUE_0xe60 PACA_IRQ_HMI #define SOFTEN_VALUE_0xea0 PACA_IRQ_EE +#define SOFTEN_VALUE_0xf00 PACA_IRQ_PMI #define __SOFTEN_TEST(h, vec, bitmask) \ lbz r10,PACASOFTIRQEN(r13); \
@@ -495,6 +496,10 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) _MASKABLE_RELON_EXCEPTION_PSERIES(vec, label, \ EXC_STD, SOFTEN_NOTEST_PR, bitmask) +#define MASKABLE_RELON_EXCEPTION_PSERIES_OOL(vec, label, bitmask) \ + MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_NOTEST_PR, vec, bitmask);\ + EXCEPTION_PROLOG_PSERIES_1(label, EXC_STD); + #define MASKABLE_RELON_EXCEPTION_HV(loc, vec, label, bitmask) \ _MASKABLE_RELON_EXCEPTION_PSERIES(vec, label, \ EXC_HV, SOFTEN_NOTEST_HV, bitmask)
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 8359fbf83376..ac9a17ea1d66 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h@@ -26,12 +26,14 @@ #define PACA_IRQ_DEC 0x08 /* Or FIT */ #define PACA_IRQ_EE_EDGE 0x10 /* BookE only */ #define PACA_IRQ_HMI 0x20 +#define PACA_IRQ_PMI 0x40 /* * flags for paca->soft_enabled */ #define IRQ_DISABLE_MASK_NONE 0 #define IRQ_DISABLE_MASK_LINUX 1 +#define IRQ_DISABLE_MASK_PMU 2 #endif /* CONFIG_PPC64 */
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index f3afa0b9332d..d021f7de79bd 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S@@ -931,6 +931,11 @@ restore_check_irq_replay: addi r3,r1,STACK_FRAME_OVERHEAD; bl do_IRQ b ret_from_except +1: cmpwi cr0,r3,0xf00 + bne 1f + addi r3,r1,STACK_FRAME_OVERHEAD; + bl performance_monitor_exception + b ret_from_except 1: cmpwi cr0,r3,0xe60 bne 1f addi r3,r1,STACK_FRAME_OVERHEAD;
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 66f5334870bf..e914b9f6cd2f 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S@@ -1041,8 +1041,8 @@ EXC_REAL_NONE(0xec0, 0xf00) EXC_VIRT_NONE(0x4ec0, 0x4f00) -EXC_REAL_OOL(performance_monitor, 0xf00, 0xf20) -EXC_VIRT_OOL(performance_monitor, 0x4f00, 0x4f20, 0xf00) +EXC_REAL_OOL_MASKABLE(performance_monitor, 0xf00, 0xf20, IRQ_DISABLE_MASK_PMU) +EXC_VIRT_OOL_MASKABLE(performance_monitor, 0x4f00, 0x4f20, 0xf00, IRQ_DISABLE_MASK_PMU) TRAMP_KVM(PACA_EXGEN, 0xf00) EXC_COMMON_ASYNC(performance_monitor_common, 0xf00, performance_monitor_exception)
@@ -1580,6 +1580,8 @@ _GLOBAL(__replay_interrupt) beq decrementer_common cmpwi r3,0x500 beq hardware_interrupt_common + cmpwi r3,0xf00 + beq performance_monitor_common BEGIN_FTR_SECTION cmpwi r3,0xe80 beq h_doorbell_common
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 5a995183dafb..c030ccd0a7aa 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c@@ -169,6 +169,27 @@ notrace unsigned int __check_irq_replay(void) if ((happened & PACA_IRQ_DEC) || decrementer_check_overflow()) return 0x900; + /* + * In masked_handler() for PMI, we disable MSR[EE] and return. + * Replay it here. + * + * After this point, PMIs could still be disabled in certain + * scenarios like this one. + * + * local_irq_disable(); + * powerpc_irq_pmu_save(); + * powerpc_irq_pmu_restore(); + * local_irq_restore(); + * + * Even though powerpc_irq_pmu_restore() would have replayed the PMIs + * if any, we have still not enabled EE and this will happen only at + * complition of last *_restore in this nested cases. And PMIs will + * once again start firing only when we have MSR[EE] enabled. + */ + local_paca->irq_happened &= ~PACA_IRQ_PMI; + if (happened & PACA_IRQ_PMI) + return 0xf00; + /* Finally check if an external interrupt happened */ local_paca->irq_happened &= ~PACA_IRQ_EE; if (happened & PACA_IRQ_EE)
@@ -208,7 +229,9 @@ notrace void arch_local_irq_restore(unsigned long en) /* Write the new soft-enabled value */ soft_enabled_set(en); - if (en == IRQ_DISABLE_MASK_LINUX) + + /* any bits still disabled */ + if (en) return; /* * From this point onward, we can take interrupts, preempt,
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2.7.4