From fe1952fc0afb9a2e4c79f103c08aef5d13db1873 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Thu, 1 Mar 2012 12:45:27 +1100 Subject: [PATCH] powerpc: Rework runlatch code This moves the inlines into system.h and changes the runlatch code to use the thread local flags (non-atomic) rather than the TIF flags (atomic) to keep track of the latch state. The code to turn it back on in an asynchronous interrupt is now simplified and partially inlined. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/exception-64s.h | 50 +++++++++++++----------- arch/powerpc/include/asm/reg.h | 22 +---------- arch/powerpc/include/asm/system.h | 38 ++++++++++++++++++ arch/powerpc/include/asm/thread_info.h | 9 ++++- arch/powerpc/kernel/exceptions-64s.S | 3 ++ arch/powerpc/kernel/process.c | 24 ++++++------ 6 files changed, 89 insertions(+), 57 deletions(-) diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index 041b2227967d..bdc9eebd1d44 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -284,35 +284,39 @@ label##_hv: \ rlwimi r11,r12,0,MSR_EE; \ mtmsrd r11,1 -#define STD_EXCEPTION_COMMON(trap, label, hdlr) \ - .align 7; \ - .globl label##_common; \ -label##_common: \ - EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \ - DISABLE_INTS; \ - bl .save_nvgprs; \ - addi r3,r1,STACK_FRAME_OVERHEAD; \ - bl hdlr; \ - b .ret_from_except +#define ADD_NVGPRS \ + bl .save_nvgprs + +#define RUNLATCH_ON \ +BEGIN_FTR_SECTION \ + clrrdi r3,r1,THREAD_SHIFT; \ + ld r4,TI_LOCAL_FLAGS(r3); \ + andi. r0,r4,_TLF_RUNLATCH; \ + beql ppc64_runlatch_on_trampoline; \ +END_FTR_SECTION_IFSET(CPU_FTR_CTRL) + +#define EXCEPTION_COMMON(trap, label, hdlr, ret, additions) \ + .align 7; \ + .globl label##_common; \ +label##_common: \ + EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \ + additions; \ + addi r3,r1,STACK_FRAME_OVERHEAD; \ + bl hdlr; \ + b ret + +#define STD_EXCEPTION_COMMON(trap, label, hdlr) \ + EXCEPTION_COMMON(trap, label, hdlr, ret_from_except, \ + ADD_NVGPRS;DISABLE_INTS) /* * Like STD_EXCEPTION_COMMON, but for exceptions that can occur * in the idle task and therefore need the special idle handling * (finish nap and runlatch) */ -#define STD_EXCEPTION_COMMON_ASYNC(trap, label, hdlr) \ - .align 7; \ - .globl label##_common; \ -label##_common: \ - EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \ - FINISH_NAP; \ - DISABLE_INTS; \ -BEGIN_FTR_SECTION \ - bl .ppc64_runlatch_on; \ -END_FTR_SECTION_IFSET(CPU_FTR_CTRL) \ - addi r3,r1,STACK_FRAME_OVERHEAD; \ - bl hdlr; \ - b .ret_from_except_lite +#define STD_EXCEPTION_COMMON_ASYNC(trap, label, hdlr) \ + EXCEPTION_COMMON(trap, label, hdlr, ret_from_except_lite, \ + FINISH_NAP;RUNLATCH_ON;DISABLE_INTS) /* * When the idle code in power4_idle puts the CPU into NAP mode, diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 7fdc2c0b7fa0..b1a215eabef6 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -1079,30 +1079,12 @@ #define proc_trap() asm volatile("trap") -#ifdef CONFIG_PPC64 - -extern void ppc64_runlatch_on(void); -extern void __ppc64_runlatch_off(void); - -#define ppc64_runlatch_off() \ - do { \ - if (cpu_has_feature(CPU_FTR_CTRL) && \ - test_thread_flag(TIF_RUNLATCH)) \ - __ppc64_runlatch_off(); \ - } while (0) +#define __get_SP() ({unsigned long sp; \ + asm volatile("mr %0,1": "=r" (sp)); sp;}) extern unsigned long scom970_read(unsigned int address); extern void scom970_write(unsigned int address, unsigned long value); -#else -#define ppc64_runlatch_on() -#define ppc64_runlatch_off() - -#endif /* CONFIG_PPC64 */ - -#define __get_SP() ({unsigned long sp; \ - asm volatile("mr %0,1": "=r" (sp)); sp;}) - struct pt_regs; extern void ppc_save_regs(struct pt_regs *regs); diff --git a/arch/powerpc/include/asm/system.h b/arch/powerpc/include/asm/system.h index c377457d1b89..a02883d5af43 100644 --- a/arch/powerpc/include/asm/system.h +++ b/arch/powerpc/include/asm/system.h @@ -550,5 +550,43 @@ extern void reloc_got2(unsigned long); extern struct dentry *powerpc_debugfs_root; +#ifdef CONFIG_PPC64 + +extern void __ppc64_runlatch_on(void); +extern void __ppc64_runlatch_off(void); + +/* + * We manually hard enable-disable, this is called + * in the idle loop and we don't want to mess up + * with soft-disable/enable & interrupt replay. + */ +#define ppc64_runlatch_off() \ + do { \ + if (cpu_has_feature(CPU_FTR_CTRL) && \ + test_thread_local_flags(_TLF_RUNLATCH)) { \ + unsigned long msr = mfmsr(); \ + __hard_irq_disable(); \ + __ppc64_runlatch_off(); \ + if (msr & MSR_EE) \ + __hard_irq_enable(); \ + } \ + } while (0) + +#define ppc64_runlatch_on() \ + do { \ + if (cpu_has_feature(CPU_FTR_CTRL) && \ + !test_thread_local_flags(_TLF_RUNLATCH)) { \ + unsigned long msr = mfmsr(); \ + __hard_irq_disable(); \ + __ppc64_runlatch_on(); \ + if (msr & MSR_EE) \ + __hard_irq_enable(); \ + } \ + } while (0) +#else +#define ppc64_runlatch_on() +#define ppc64_runlatch_off() +#endif /* CONFIG_PPC64 */ + #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_SYSTEM_H */ diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index 964714940961..4a741c7efd02 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -110,7 +110,6 @@ static inline struct thread_info *current_thread_info(void) #define TIF_NOERROR 12 /* Force successful syscall return */ #define TIF_NOTIFY_RESUME 13 /* callback before returning to user */ #define TIF_SYSCALL_TRACEPOINT 15 /* syscall tracepoint instrumentation */ -#define TIF_RUNLATCH 16 /* Is the runlatch enabled? */ /* as above, but as bit values */ #define _TIF_SYSCALL_TRACE (1<flags); } +static inline bool test_thread_local_flags(unsigned int flags) +{ + struct thread_info *ti = current_thread_info(); + return (ti->local_flags & flags) != 0; +} + #ifdef CONFIG_PPC64 #define is_32bit_task() (test_thread_flag(TIF_32BIT)) #else diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 2240d4ecec02..3af80e82830b 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -483,6 +483,9 @@ machine_check_common: system_call_entry: b system_call_common +ppc64_runlatch_on_trampoline: + b .__ppc64_runlatch_on + /* * Here we have detected that the kernel stack pointer is bad. * R9 contains the saved CR, r13 points to the paca, diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index d817ab018486..bf80a1d5f8fe 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1220,34 +1220,32 @@ void dump_stack(void) EXPORT_SYMBOL(dump_stack); #ifdef CONFIG_PPC64 -void ppc64_runlatch_on(void) +/* Called with hard IRQs off */ +void __ppc64_runlatch_on(void) { + struct thread_info *ti = current_thread_info(); unsigned long ctrl; - if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) { - HMT_medium(); - - ctrl = mfspr(SPRN_CTRLF); - ctrl |= CTRL_RUNLATCH; - mtspr(SPRN_CTRLT, ctrl); + ctrl = mfspr(SPRN_CTRLF); + ctrl |= CTRL_RUNLATCH; + mtspr(SPRN_CTRLT, ctrl); - set_thread_flag(TIF_RUNLATCH); - } + ti->local_flags |= TLF_RUNLATCH; } +/* Called with hard IRQs off */ void __ppc64_runlatch_off(void) { + struct thread_info *ti = current_thread_info(); unsigned long ctrl; - HMT_medium(); - - clear_thread_flag(TIF_RUNLATCH); + ti->local_flags &= ~TLF_RUNLATCH; ctrl = mfspr(SPRN_CTRLF); ctrl &= ~CTRL_RUNLATCH; mtspr(SPRN_CTRLT, ctrl); } -#endif +#endif /* CONFIG_PPC64 */ #if THREAD_SHIFT < PAGE_SHIFT -- 2.20.1