3.10-stable review patch. If anyone has any objections, please let me know.
------------------ From: Vineet Gupta <[email protected]> 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 <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/arc/include/asm/irqflags.h | 7 ------- arch/arc/kernel/entry.S | 10 +++++----- 2 files changed, 5 insertions(+), 12 deletions(-) --- a/arch/arc/include/asm/irqflags.h +++ b/arch/arc/include/asm/irqflags.h @@ -137,13 +137,6 @@ static inline void arch_unmask_irq(unsig 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) --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -653,6 +653,9 @@ 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] @@ -662,8 +665,6 @@ 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 @@ -676,12 +677,11 @@ 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] #ifdef CONFIG_ARC_CURR_IN_REG ; Restore User R25 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
