diff options
Diffstat (limited to 'arch/powerpc/kernel/idle_power7.S')
| -rw-r--r-- | arch/powerpc/kernel/idle_power7.S | 197 |
1 files changed, 153 insertions, 44 deletions
diff --git a/arch/powerpc/kernel/idle_power7.S b/arch/powerpc/kernel/idle_power7.S index e5aba6a..0f2c113 100644 --- a/arch/powerpc/kernel/idle_power7.S +++ b/arch/powerpc/kernel/idle_power7.S @@ -18,6 +18,7 @@ #include <asm/hw_irq.h> #include <asm/kvm_book3s_asm.h> #include <asm/opal.h> +#include <asm/cpuidle.h> #undef DEBUG @@ -37,8 +38,7 @@ /* * Pass requested state in r3: - * 0 - nap - * 1 - sleep + * r3 - PNV_THREAD_NAP/SLEEP/WINKLE * * To check IRQ_HAPPENED in r4 * 0 - don't check @@ -123,12 +123,58 @@ power7_enter_nap_mode: li r4,KVM_HWTHREAD_IN_NAP stb r4,HSTATE_HWTHREAD_STATE(r13) #endif - cmpwi cr0,r3,1 - beq 2f + stb r3,PACA_THREAD_IDLE_STATE(r13) + cmpwi cr1,r3,PNV_THREAD_SLEEP + bge cr1,2f IDLE_STATE_ENTER_SEQ(PPC_NAP) /* No return */ -2: IDLE_STATE_ENTER_SEQ(PPC_SLEEP) - /* No return */ +2: + /* Sleep or winkle */ + lbz r7,PACA_THREAD_MASK(r13) + ld r14,PACA_CORE_IDLE_STATE_PTR(r13) +lwarx_loop1: + lwarx r15,0,r14 + andc r15,r15,r7 /* Clear thread bit */ + + andi. r15,r15,PNV_CORE_IDLE_THREAD_BITS + +/* + * If cr0 = 0, then current thread is the last thread of the core entering + * sleep. Last thread needs to execute the hardware bug workaround code if + * required by the platform. + * Make the workaround call unconditionally here. The below branch call is + * patched out when the idle states are discovered if the platform does not + * require it. + */ +.global pnv_fastsleep_workaround_at_entry +pnv_fastsleep_workaround_at_entry: + beq fastsleep_workaround_at_entry + + stwcx. r15,0,r14 + bne- lwarx_loop1 + isync + +common_enter: /* common code for all the threads entering sleep */ + IDLE_STATE_ENTER_SEQ(PPC_SLEEP) + +fastsleep_workaround_at_entry: + ori r15,r15,PNV_CORE_IDLE_LOCK_BIT + stwcx. r15,0,r14 + bne- lwarx_loop1 + isync + + /* Fast sleep workaround */ + li r3,1 + li r4,1 + li r0,OPAL_CONFIG_CPU_IDLE_STATE + bl opal_call_realmode + + /* Clear Lock bit */ + li r0,0 + lwsync + stw r0,0(r14) + b common_enter + _GLOBAL(power7_idle) /* Now check if user or arch enabled NAP mode */ @@ -141,49 +187,16 @@ _GLOBAL(power7_idle) _GLOBAL(power7_nap) mr r4,r3 - li r3,0 + li r3,PNV_THREAD_NAP b power7_powersave_common /* No return */ _GLOBAL(power7_sleep) - li r3,1 + li r3,PNV_THREAD_SLEEP li r4,1 b power7_powersave_common /* No return */ -/* - * Make opal call in realmode. This is a generic function to be called - * from realmode from reset vector. It handles endianess. - * - * r13 - paca pointer - * r1 - stack pointer - * r3 - opal token - */ -opal_call_realmode: - mflr r12 - std r12,_LINK(r1) - ld r2,PACATOC(r13) - /* Set opal return address */ - LOAD_REG_ADDR(r0,return_from_opal_call) - mtlr r0 - /* Handle endian-ness */ - li r0,MSR_LE - mfmsr r12 - andc r12,r12,r0 - mtspr SPRN_HSRR1,r12 - mr r0,r3 /* Move opal token to r0 */ - LOAD_REG_ADDR(r11,opal) - ld r12,8(r11) - ld r2,0(r11) - mtspr SPRN_HSRR0,r12 - hrfid - -return_from_opal_call: - FIXUP_ENDIAN - ld r0,_LINK(r1) - mtlr r0 - blr - #define CHECK_HMI_INTERRUPT \ mfspr r0,SPRN_SRR1; \ BEGIN_FTR_SECTION_NESTED(66); \ @@ -197,7 +210,7 @@ ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 66); \ ld r2,PACATOC(r13); \ ld r1,PACAR1(r13); \ std r3,ORIG_GPR3(r1); /* Save original r3 */ \ - li r3,OPAL_HANDLE_HMI; /* Pass opal token argument*/ \ + li r0,OPAL_HANDLE_HMI; /* Pass opal token argument*/ \ bl opal_call_realmode; \ ld r3,ORIG_GPR3(r1); /* Restore original r3 */ \ 20: nop; @@ -206,16 +219,105 @@ ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 66); \ _GLOBAL(power7_wakeup_tb_loss) ld r2,PACATOC(r13); ld r1,PACAR1(r13) + /* + * Before entering any idle state, the NVGPRs are saved in the stack + * and they are restored before switching to the process context. Hence + * until they are restored, they are free to be used. + * + * Save SRR1 in a NVGPR as it might be clobbered in opal_call_realmode + * (called in CHECK_HMI_INTERRUPT). SRR1 is required to determine the + * wakeup reason if we branch to kvm_start_guest. + */ + mfspr r16,SPRN_SRR1 BEGIN_FTR_SECTION CHECK_HMI_INTERRUPT END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) + + lbz r7,PACA_THREAD_MASK(r13) + ld r14,PACA_CORE_IDLE_STATE_PTR(r13) +lwarx_loop2: + lwarx r15,0,r14 + andi. r9,r15,PNV_CORE_IDLE_LOCK_BIT + /* + * Lock bit is set in one of the 2 cases- + * a. In the sleep/winkle enter path, the last thread is executing + * fastsleep workaround code. + * b. In the wake up path, another thread is executing fastsleep + * workaround undo code or resyncing timebase or restoring context + * In either case loop until the lock bit is cleared. + */ + bne core_idle_lock_held + + cmpwi cr2,r15,0 + or r15,r15,r7 /* Set thread bit */ + + beq cr2,first_thread + + /* Not first thread in core to wake up */ + stwcx. r15,0,r14 + bne- lwarx_loop2 + isync + b common_exit + +core_idle_lock_held: + HMT_LOW +core_idle_lock_loop: + lwz r15,0(14) + andi. r9,r15,PNV_CORE_IDLE_LOCK_BIT + bne core_idle_lock_loop + HMT_MEDIUM + b lwarx_loop2 + +first_thread: + /* First thread in core to wakeup */ + ori r15,r15,PNV_CORE_IDLE_LOCK_BIT + stwcx. r15,0,r14 + bne- lwarx_loop2 + isync + + /* + * First thread in the core waking up from fastsleep. It needs to + * call the fastsleep workaround code if the platform requires it. + * Call it unconditionally here. The below branch instruction will + * be patched out when the idle states are discovered if platform + * does not require workaround. + */ +.global pnv_fastsleep_workaround_at_exit +pnv_fastsleep_workaround_at_exit: + b fastsleep_workaround_at_exit + +timebase_resync: + /* Do timebase resync if we are waking up from sleep. Use cr3 value + * set in exceptions-64s.S */ + ble cr3,clear_lock /* Time base re-sync */ - li r3,OPAL_RESYNC_TIMEBASE + li r0,OPAL_RESYNC_TIMEBASE bl opal_call_realmode; - /* TODO: Check r3 for failure */ +clear_lock: + andi. r15,r15,PNV_CORE_IDLE_THREAD_BITS + lwsync + stw r15,0(r14) + +common_exit: + li r5,PNV_THREAD_RUNNING + stb r5,PACA_THREAD_IDLE_STATE(r13) + + mtspr SPRN_SRR1,r16 +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + li r0,KVM_HWTHREAD_IN_KERNEL + stb r0,HSTATE_HWTHREAD_STATE(r13) + /* Order setting hwthread_state vs. testing hwthread_req */ + sync + lbz r0,HSTATE_HWTHREAD_REQ(r13) + cmpwi r0,0 + beq 6f + b kvm_start_guest +6: +#endif + REST_NVGPRS(r1) REST_GPR(2, r1) ld r3,_CCR(r1) @@ -228,6 +330,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) mtspr SPRN_SRR0,r5 rfid +fastsleep_workaround_at_exit: + li r3,1 + li r4,0 + li r0,OPAL_CONFIG_CPU_IDLE_STATE + bl opal_call_realmode + b timebase_resync + /* * R3 here contains the value that will be returned to the caller * of power7_nap. |
