3.11.10.10 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Vineet Gupta <vgupta@xxxxxxxxxxxx> commit fce16bc35ae4a45634f3dc348d8d297a25c277cf upstream. In the exception return path, for both U/K cases, intr are already disabled (for various existing reasons). So when we drop down to @restore_regs, we need not redo that. There was subtle issue - when intr were NOT being disabled for ret-to-kernel-but-no-preemption case - now fixed by moving the IRQ_DISABLE further up in @resume_kernel_mode. So what do we gain: * Shaves off a few insn in return path. * Eliminates the need for IRQ_DISABLE_SAVE assembler macro for ARCv2 hence allows for entry code sharing. Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx> Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx> --- arch/arc/include/asm/irqflags.h | 7 ------- arch/arc/kernel/entry.S | 10 +++++----- 2 files changed, 5 insertions(+), 12 deletions(-) diff --git a/arch/arc/include/asm/irqflags.h b/arch/arc/include/asm/irqflags.h index d99f79b..b68b53f 100644 --- a/arch/arc/include/asm/irqflags.h +++ b/arch/arc/include/asm/irqflags.h @@ -157,13 +157,6 @@ static inline void arch_unmask_irq(unsigned int irq) flag \scratch .endm -.macro IRQ_DISABLE_SAVE scratch, save - lr \scratch, [status32] - mov \save, \scratch /* Make a copy */ - bic \scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK) - flag \scratch -.endm - .macro IRQ_ENABLE scratch lr \scratch, [status32] or \scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK) diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S index 1d71651..89f7961 100644 --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -642,6 +642,9 @@ resume_kernel_mode: #ifdef CONFIG_PREEMPT + ; This is a must for preempt_schedule_irq() + IRQ_DISABLE r9 + ; Can't preempt if preemption disabled GET_CURR_THR_INFO_FROM_SP r10 ld r8, [r10, THREAD_INFO_PREEMPT_COUNT] @@ -651,8 +654,6 @@ resume_kernel_mode: ld r9, [r10, THREAD_INFO_FLAGS] bbit0 r9, TIF_NEED_RESCHED, restore_regs - IRQ_DISABLE r9 - ; Invoke PREEMPTION bl preempt_schedule_irq @@ -665,12 +666,11 @@ resume_kernel_mode: ; ; Restore the saved sys context (common exit-path for EXCPN/IRQ/Trap) ; IRQ shd definitely not happen between now and rtie +; All 2 entry points to here already disable interrupts restore_regs : - ; Disable Interrupts while restoring reg-file back - ; XXX can this be optimised out - IRQ_DISABLE_SAVE r9, r10 ;@r10 has prisitine (pre-disable) copy + lr r10, [status32] ; Restore REG File. In case multiple Events outstanding, ; use the same priorty as rtie: EXCPN, L2 IRQ, L1 IRQ, None -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html