From: Vineet Gupta Date: Fri, 23 Sep 2016 21:09:30 +0000 (-0700) Subject: ARCv2: entry: document intr disable in hard isr X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=78833e79d516901413d6e9278cbebf6116d62c78;p=linux-beck.git ARCv2: entry: document intr disable in hard isr And while at it - use the proper assembler macro which includes the optional irq tracing already - de-uglify'ing the code a bit Signed-off-by: Vineet Gupta --- diff --git a/arch/arc/kernel/entry-arcv2.S b/arch/arc/kernel/entry-arcv2.S index 7a1c124ff021..0b6388a5f0b8 100644 --- a/arch/arc/kernel/entry-arcv2.S +++ b/arch/arc/kernel/entry-arcv2.S @@ -67,12 +67,23 @@ ENTRY(handle_interrupt) INTERRUPT_PROLOGUE irq - clri ; To make status32.IE agree with CPU internal state - -#ifdef CONFIG_TRACE_IRQFLAGS - TRACE_ASM_IRQ_DISABLE -#endif - + # irq control APIs local_irq_save/restore/disable/enable fiddle with + # global interrupt enable bits in STATUS32 (.IE for 1 prio, .E[] for 2 prio) + # However a taken interrupt doesn't clear these bits. Thus irqs_disabled() + # query in hard ISR path would return false (since .IE is set) which would + # trips genirq interrupt handling asserts. + # + # So do a "soft" disable of interrutps here. + # + # Note this disable is only for consistent book-keeping as further interrupts + # will be disabled anyways even w/o this. Hardware tracks active interrupts + # seperately in AUX_IRQ_ACTIVE.active and will not take new interrupts + # unless this one returns (or higher prio becomes pending in 2-prio scheme) + + IRQ_DISABLE + + ; icause is banked: one per priority level + ; so a higher prio interrupt taken here won't clobber prev prio icause lr r0, [ICAUSE] mov blink, ret_from_exception @@ -171,6 +182,7 @@ END(EV_TLBProtV) ; All 2 entry points to here already disable interrupts .Lrestore_regs: +restore_regs: # Interrpts are actually disabled from this point on, but will get # reenabled after we return from interrupt/exception.