| Subject: powerpc-preempt-lazy-support.patch |
| From: Thomas Gleixner <tglx@linutronix.de> |
| Date: Thu, 01 Nov 2012 10:14:11 +0100 |
| |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| --- |
| arch/powerpc/Kconfig | 1 + |
| arch/powerpc/include/asm/thread_info.h | 7 ++++++- |
| arch/powerpc/kernel/asm-offsets.c | 1 + |
| arch/powerpc/kernel/entry_32.S | 19 +++++++++++++------ |
| arch/powerpc/kernel/entry_64.S | 17 +++++++++++------ |
| 5 files changed, 32 insertions(+), 13 deletions(-) |
| |
| Index: linux-stable/arch/powerpc/Kconfig |
| =================================================================== |
| --- linux-stable.orig/arch/powerpc/Kconfig |
| +++ linux-stable/arch/powerpc/Kconfig |
| @@ -140,6 +140,7 @@ config PPC |
| select GENERIC_CLOCKEVENTS |
| select GENERIC_STRNCPY_FROM_USER |
| select GENERIC_STRNLEN_USER |
| + select HAVE_PREEMPT_LAZY |
| |
| config EARLY_PRINTK |
| bool |
| Index: linux-stable/arch/powerpc/include/asm/thread_info.h |
| =================================================================== |
| --- linux-stable.orig/arch/powerpc/include/asm/thread_info.h |
| +++ linux-stable/arch/powerpc/include/asm/thread_info.h |
| @@ -43,6 +43,8 @@ struct thread_info { |
| int cpu; /* cpu we're on */ |
| int preempt_count; /* 0 => preemptable, |
| <0 => BUG */ |
| + int preempt_lazy_count; /* 0 => preemptable, |
| + <0 => BUG */ |
| struct restart_block restart_block; |
| unsigned long local_flags; /* private flags for thread */ |
| |
| @@ -102,12 +104,14 @@ static inline struct thread_info *curren |
| #define TIF_RESTOREALL 11 /* Restore all regs (implies NOERROR) */ |
| #define TIF_NOERROR 12 /* Force successful syscall return */ |
| #define TIF_NOTIFY_RESUME 13 /* callback before returning to user */ |
| +#define TIF_NEED_RESCHED_LAZY 14 /* lazy rescheduling necessary */ |
| #define TIF_SYSCALL_TRACEPOINT 15 /* syscall tracepoint instrumentation */ |
| |
| /* as above, but as bit values */ |
| #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) |
| #define _TIF_SIGPENDING (1<<TIF_SIGPENDING) |
| #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED) |
| +#define _TIF_NEED_RESCHED_LAZY (1<<TIF_NEED_RESCHED_LAZY) |
| #define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG) |
| #define _TIF_32BIT (1<<TIF_32BIT) |
| #define _TIF_PERFMON_WORK (1<<TIF_PERFMON_WORK) |
| @@ -123,8 +127,9 @@ static inline struct thread_info *curren |
| _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT) |
| |
| #define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \ |
| - _TIF_NOTIFY_RESUME) |
| + _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED_LAZY) |
| #define _TIF_PERSYSCALL_MASK (_TIF_RESTOREALL|_TIF_NOERROR) |
| +#define _TIF_NEED_RESCHED_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY) |
| |
| /* Bits in local_flags */ |
| /* Don't move TLF_NAPPING without adjusting the code in entry_32.S */ |
| Index: linux-stable/arch/powerpc/kernel/asm-offsets.c |
| =================================================================== |
| --- linux-stable.orig/arch/powerpc/kernel/asm-offsets.c |
| +++ linux-stable/arch/powerpc/kernel/asm-offsets.c |
| @@ -124,6 +124,7 @@ int main(void) |
| DEFINE(TI_FLAGS, offsetof(struct thread_info, flags)); |
| DEFINE(TI_LOCAL_FLAGS, offsetof(struct thread_info, local_flags)); |
| DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count)); |
| + DEFINE(TI_PREEMPT_LAZY, offsetof(struct thread_info, preempt_lazy_count)); |
| DEFINE(TI_TASK, offsetof(struct thread_info, task)); |
| DEFINE(TI_CPU, offsetof(struct thread_info, cpu)); |
| |
| Index: linux-stable/arch/powerpc/kernel/entry_32.S |
| =================================================================== |
| --- linux-stable.orig/arch/powerpc/kernel/entry_32.S |
| +++ linux-stable/arch/powerpc/kernel/entry_32.S |
| @@ -843,8 +843,15 @@ resume_kernel: |
| bne restore |
| lwz r0,TI_FLAGS(r9) |
| andi. r0,r0,_TIF_NEED_RESCHED |
| + bne+ 1f |
| + lwz r0,TI_PREEMPT_LAZY(r9) |
| + cmpwi 0,r0,0 /* if non-zero, just restore regs and return */ |
| + bne restore |
| + lwz r0,TI_FLAGS(r9) |
| + andi. r0,r0,_TIF_NEED_RESCHED_LAZY |
| beq+ restore |
| - andi. r0,r3,MSR_EE /* interrupts off? */ |
| + |
| +1: andi. r0,r3,MSR_EE /* interrupts off? */ |
| beq restore /* don't schedule if so */ |
| #ifdef CONFIG_TRACE_IRQFLAGS |
| /* Lockdep thinks irqs are enabled, we need to call |
| @@ -853,11 +860,11 @@ resume_kernel: |
| */ |
| bl trace_hardirqs_off |
| #endif |
| -1: bl preempt_schedule_irq |
| +2: bl preempt_schedule_irq |
| CURRENT_THREAD_INFO(r9, r1) |
| lwz r3,TI_FLAGS(r9) |
| - andi. r0,r3,_TIF_NEED_RESCHED |
| - bne- 1b |
| + andi. r0,r3,_TIF_NEED_RESCHED_MASK |
| + bne- 2b |
| #ifdef CONFIG_TRACE_IRQFLAGS |
| /* And now, to properly rebalance the above, we tell lockdep they |
| * are being turned back on, which will happen when we return |
| @@ -1180,7 +1187,7 @@ global_dbcr0: |
| #endif /* !(CONFIG_4xx || CONFIG_BOOKE) */ |
| |
| do_work: /* r10 contains MSR_KERNEL here */ |
| - andi. r0,r9,_TIF_NEED_RESCHED |
| + andi. r0,r9,_TIF_NEED_RESCHED_MASK |
| beq do_user_signal |
| |
| do_resched: /* r10 contains MSR_KERNEL here */ |
| @@ -1201,7 +1208,7 @@ recheck: |
| MTMSRD(r10) /* disable interrupts */ |
| CURRENT_THREAD_INFO(r9, r1) |
| lwz r9,TI_FLAGS(r9) |
| - andi. r0,r9,_TIF_NEED_RESCHED |
| + andi. r0,r9,_TIF_NEED_RESCHED_MASK |
| bne- do_resched |
| andi. r0,r9,_TIF_USER_WORK_MASK |
| beq restore_user |
| Index: linux-stable/arch/powerpc/kernel/entry_64.S |
| =================================================================== |
| --- linux-stable.orig/arch/powerpc/kernel/entry_64.S |
| +++ linux-stable/arch/powerpc/kernel/entry_64.S |
| @@ -580,7 +580,7 @@ _GLOBAL(ret_from_except_lite) |
| andi. r0,r4,_TIF_USER_WORK_MASK |
| beq restore |
| |
| - andi. r0,r4,_TIF_NEED_RESCHED |
| + andi. r0,r4,_TIF_NEED_RESCHED_MASK |
| beq 1f |
| bl .restore_interrupts |
| bl .schedule |
| @@ -595,11 +595,16 @@ _GLOBAL(ret_from_except_lite) |
| resume_kernel: |
| #ifdef CONFIG_PREEMPT |
| /* Check if we need to preempt */ |
| + lwz r8,TI_PREEMPT(r9) |
| andi. r0,r4,_TIF_NEED_RESCHED |
| + bne+ 1f |
| + |
| + andi. r0,r4,_TIF_NEED_RESCHED_LAZY |
| beq+ restore |
| + lwz r8,TI_PREEMPT_LAZY(r9) |
| + |
| /* Check that preempt_count() == 0 and interrupts are enabled */ |
| - lwz r8,TI_PREEMPT(r9) |
| - cmpwi cr1,r8,0 |
| +1: cmpwi cr1,r8,0 |
| ld r0,SOFTE(r1) |
| cmpdi r0,0 |
| crandc eq,cr1*4+eq,eq |
| @@ -610,13 +615,13 @@ resume_kernel: |
| * sure we are soft-disabled first |
| */ |
| SOFT_DISABLE_INTS(r3,r4) |
| -1: bl .preempt_schedule_irq |
| +2: bl .preempt_schedule_irq |
| |
| /* Re-test flags and eventually loop */ |
| CURRENT_THREAD_INFO(r9, r1) |
| ld r4,TI_FLAGS(r9) |
| - andi. r0,r4,_TIF_NEED_RESCHED |
| - bne 1b |
| + andi. r0,r4,_TIF_NEED_RESCHED_MASK |
| + bne 2b |
| #endif /* CONFIG_PREEMPT */ |
| |
| .globl fast_exc_return_irq |
