Re: [RFC PATCH 12/12] powerpc/64s: power4 nap fixup in C
From: Christophe Leroy <hidden>
Date: 2020-09-06 07:34:04
Le 05/09/2020 à 19:43, Nicholas Piggin a écrit :
quoted hunk ↗ jump to hunk
There is no need for this to be in asm, use the new intrrupt entry wrapper. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/include/asm/interrupt.h | 14 ++++++++ arch/powerpc/include/asm/processor.h | 1 + arch/powerpc/include/asm/thread_info.h | 6 ++++ arch/powerpc/kernel/exceptions-64s.S | 45 -------------------------- arch/powerpc/kernel/idle_book3s.S | 4 +++ 5 files changed, 25 insertions(+), 45 deletions(-)diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h index 3ae3d2f93b61..acfcc7d5779b 100644 --- a/arch/powerpc/include/asm/interrupt.h +++ b/arch/powerpc/include/asm/interrupt.h@@ -8,6 +8,16 @@ #include <asm/ftrace.h> #include <asm/runlatch.h> +static inline void nap_adjust_return(struct pt_regs *regs) +{ +#ifdef CONFIG_PPC_970_NAP
Avoid #ifdef, you can use IS_ENABLED(CONFIG_PPC_970_NAP) in the 'if' below
quoted hunk ↗ jump to hunk
+ if (test_thread_local_flags(_TLF_NAPPING)) { + clear_thread_local_flags(_TLF_NAPPING); + regs->nip = (unsigned long)power4_idle_nap_return; + } +#endif +} + #ifdef CONFIG_PPC_BOOK3S_64 static inline void interrupt_enter_prepare(struct pt_regs *regs) {@@ -33,6 +43,8 @@ static inline void interrupt_async_enter_prepare(struct pt_regs *regs) if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_local_flags(_TLF_RUNLATCH)) __ppc64_runlatch_on(); + + nap_adjust_return(regs); } #else /* CONFIG_PPC_BOOK3S_64 */@@ -72,6 +84,8 @@ static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct inte this_cpu_set_ftrace_enabled(0); + nap_adjust_return(regs); + nmi_enter(); }diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index ed0d633ab5aa..3da1dba91386 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h@@ -424,6 +424,7 @@ extern unsigned long isa300_idle_stop_mayloss(unsigned long psscr_val); extern unsigned long isa206_idle_insn_mayloss(unsigned long type); #ifdef CONFIG_PPC_970_NAP extern void power4_idle_nap(void); +extern void power4_idle_nap_return(void);
Please please please, 'extern' keyword is pointless and deprecated for function prototypes. Don't add new ones. Also, put it outside the #ifdef, so that you can use IS_ENABLED() instead of #ifdef when using it.
quoted hunk ↗ jump to hunk
#endif extern unsigned long cpuidle_disable;diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index ca6c97025704..9b15f7edb0cb 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h@@ -156,6 +156,12 @@ void arch_setup_new_exec(void); #ifndef __ASSEMBLY__ +static inline void clear_thread_local_flags(unsigned int flags) +{ + struct thread_info *ti = current_thread_info(); + ti->local_flags &= ~flags; +} + static inline bool test_thread_local_flags(unsigned int flags) { struct thread_info *ti = current_thread_info();diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 227bad3a586d..1db6b3438c88 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S@@ -692,25 +692,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) ld r1,GPR1(r1) .endm -/* - * When the idle code in power4_idle puts the CPU into NAP mode, - * it has to do so in a loop, and relies on the external interrupt - * and decrementer interrupt entry code to get it out of the loop. - * It sets the _TLF_NAPPING bit in current_thread_info()->local_flags - * to signal that it is in the loop and needs help to get out. - */ -#ifdef CONFIG_PPC_970_NAP -#define FINISH_NAP \ -BEGIN_FTR_SECTION \ - ld r11, PACA_THREAD_INFO(r13); \ - ld r9,TI_LOCAL_FLAGS(r11); \ - andi. r10,r9,_TLF_NAPPING; \ - bnel power4_fixup_nap; \ -END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP) -#else -#define FINISH_NAP -#endif - /* * There are a few constraints to be concerned with. * - Real mode exceptions code/data must be located at their physical location.@@ -1250,7 +1231,6 @@ EXC_COMMON_BEGIN(machine_check_common) */ GEN_COMMON machine_check - FINISH_NAP /* Enable MSR_RI when finished with PACA_EXMC */ li r10,MSR_RI mtmsrd r10,1@@ -1572,7 +1552,6 @@ EXC_VIRT_BEGIN(hardware_interrupt, 0x4500, 0x100) EXC_VIRT_END(hardware_interrupt, 0x4500, 0x100) EXC_COMMON_BEGIN(hardware_interrupt_common) GEN_COMMON hardware_interrupt - FINISH_NAP addi r3,r1,STACK_FRAME_OVERHEAD bl do_IRQ b interrupt_return@@ -1757,7 +1736,6 @@ EXC_VIRT_BEGIN(decrementer, 0x4900, 0x80) EXC_VIRT_END(decrementer, 0x4900, 0x80) EXC_COMMON_BEGIN(decrementer_common) GEN_COMMON decrementer - FINISH_NAP addi r3,r1,STACK_FRAME_OVERHEAD bl timer_interrupt b interrupt_return@@ -1842,7 +1820,6 @@ EXC_VIRT_BEGIN(doorbell_super, 0x4a00, 0x100) EXC_VIRT_END(doorbell_super, 0x4a00, 0x100) EXC_COMMON_BEGIN(doorbell_super_common) GEN_COMMON doorbell_super - FINISH_NAP addi r3,r1,STACK_FRAME_OVERHEAD #ifdef CONFIG_PPC_DOORBELL bl doorbell_exception@@ -2196,7 +2173,6 @@ EXC_COMMON_BEGIN(hmi_exception_early_common) EXC_COMMON_BEGIN(hmi_exception_common) GEN_COMMON hmi_exception - FINISH_NAP addi r3,r1,STACK_FRAME_OVERHEAD bl handle_hmi_exception b interrupt_return@@ -2225,7 +2201,6 @@ EXC_VIRT_BEGIN(h_doorbell, 0x4e80, 0x20) EXC_VIRT_END(h_doorbell, 0x4e80, 0x20) EXC_COMMON_BEGIN(h_doorbell_common) GEN_COMMON h_doorbell - FINISH_NAP addi r3,r1,STACK_FRAME_OVERHEAD #ifdef CONFIG_PPC_DOORBELL bl doorbell_exception@@ -2258,7 +2233,6 @@ EXC_VIRT_BEGIN(h_virt_irq, 0x4ea0, 0x20) EXC_VIRT_END(h_virt_irq, 0x4ea0, 0x20) EXC_COMMON_BEGIN(h_virt_irq_common) GEN_COMMON h_virt_irq - FINISH_NAP addi r3,r1,STACK_FRAME_OVERHEAD bl do_IRQ b interrupt_return@@ -2304,7 +2278,6 @@ EXC_VIRT_BEGIN(performance_monitor, 0x4f00, 0x20) EXC_VIRT_END(performance_monitor, 0x4f00, 0x20) EXC_COMMON_BEGIN(performance_monitor_common) GEN_COMMON performance_monitor - FINISH_NAP addi r3,r1,STACK_FRAME_OVERHEAD bl performance_monitor_exception b interrupt_return@@ -3032,24 +3005,6 @@ USE_FIXED_SECTION(virt_trampolines) __end_interrupts: DEFINE_FIXED_SYMBOL(__end_interrupts) -#ifdef CONFIG_PPC_970_NAP - /* - * Called by exception entry code if _TLF_NAPPING was set, this clears - * the NAPPING flag, and redirects the exception exit to - * power4_fixup_nap_return. - */ - .globl power4_fixup_nap -EXC_COMMON_BEGIN(power4_fixup_nap) - andc r9,r9,r10 - std r9,TI_LOCAL_FLAGS(r11) - LOAD_REG_ADDR(r10, power4_idle_nap_return) - std r10,_NIP(r1) - blr - -power4_idle_nap_return: - blr -#endif - CLOSE_FIXED_SECTION(real_vectors); CLOSE_FIXED_SECTION(real_trampolines); CLOSE_FIXED_SECTION(virt_vectors);diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index 22f249b6f58d..27d2e6a72ec9 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S@@ -201,4 +201,8 @@ _GLOBAL(power4_idle_nap) mtmsrd r7 isync b 1b + + .globl power4_idle_nap_return +power4_idle_nap_return: + blr
Can't this be written in C somewhere ?
#endif
Christophe