From bc1a298f4e04833db4c430df59b90039f0170515 Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Wed, 7 Aug 2013 11:36:54 -0400 Subject: tile: support CONFIG_PREEMPT This change adds support for CONFIG_PREEMPT (full kernel preemption). In addition to the core support, this change includes a number of places where we fix up uses of smp_processor_id() and per-cpu variables. I also eliminate the PAGE_HOME_HERE and PAGE_HOME_UNKNOWN values for page homing, as it turns out they weren't being used. Signed-off-by: Chris Metcalf --- arch/tile/kernel/intvec_64.S | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-) (limited to 'arch/tile/kernel/intvec_64.S') diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S index 884af9ea5bed..38a60f27707c 100644 --- a/arch/tile/kernel/intvec_64.S +++ b/arch/tile/kernel/intvec_64.S @@ -30,10 +30,6 @@ #include #include -#ifdef CONFIG_PREEMPT -# error "No support for kernel preemption currently" -#endif - #define PTREGS_PTR(reg, ptreg) addli reg, sp, C_ABI_SAVE_AREA_SIZE + (ptreg) #define PTREGS_OFFSET_SYSCALL PTREGS_OFFSET_REG(TREG_SYSCALL_NR) @@ -820,11 +816,33 @@ STD_ENTRY(interrupt_return) andi r29, r29, SPR_EX_CONTEXT_1_1__PL_MASK /* mask off ICS */ { beqzt r29, .Lresume_userspace - PTREGS_PTR(r29, PTREGS_OFFSET_PC) + move r29, sp + } + +#ifdef CONFIG_PREEMPT + /* Returning to kernel space. Check if we need preemption. */ + EXTRACT_THREAD_INFO(r29) + addli r28, r29, THREAD_INFO_FLAGS_OFFSET + { + ld r28, r28 + addli r29, r29, THREAD_INFO_PREEMPT_COUNT_OFFSET } + { + andi r28, r28, _TIF_NEED_RESCHED + ld4s r29, r29 + } + beqzt r28, 1f + bnez r29, 1f + jal preempt_schedule_irq + FEEDBACK_REENTER(interrupt_return) +1: +#endif /* If we're resuming to _cpu_idle_nap, bump PC forward by 8. */ - moveli r27, hw2_last(_cpu_idle_nap) + { + moveli r27, hw2_last(_cpu_idle_nap) + PTREGS_PTR(r29, PTREGS_OFFSET_PC) + } { ld r28, r29 shl16insli r27, r27, hw1(_cpu_idle_nap) -- cgit v1.2.3