* [PATCH v10 0/2] powerpc/64s: reimplement book3s idle code in C @ 2019-04-28 11:45 ` Nicholas Piggin 0 siblings, 0 replies; 10+ messages in thread From: Nicholas Piggin @ 2019-04-28 11:45 UTC (permalink / raw) To: linuxppc-dev; +Cc: Gautham R . Shenoy, kvm-ppc, Nicholas Piggin The KVM code is in better shape now, survives various testing I came up with, so should be ready for more review. I won't post it again with the KVM part split out unless significant changes are required there. As explained in the comments for patch 1, the split results in some intermediate KVM issues, but the split is supposed to make KVM review easier. Gautham I left your review tag, quite a lot of KVM changes since he reviewed it, but non-KVM patch is not much different. Let me know if I should drop it. Thanks, Nick Nicholas Piggin (2): powerpc/64s: reimplement book3s idle code in C powerpc/64s: KVM update for reimplement book3s idle code in C arch/powerpc/include/asm/cpuidle.h | 19 +- arch/powerpc/include/asm/paca.h | 40 +- arch/powerpc/include/asm/processor.h | 9 +- arch/powerpc/include/asm/reg.h | 8 +- arch/powerpc/kernel/asm-offsets.c | 18 - arch/powerpc/kernel/exceptions-64s.S | 23 +- arch/powerpc/kernel/idle_book3s.S | 1099 +++------------------- arch/powerpc/kernel/setup-common.c | 4 +- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 118 ++- arch/powerpc/platforms/powernv/idle.c | 902 ++++++++++++++---- arch/powerpc/platforms/powernv/subcore.c | 2 +- arch/powerpc/xmon/xmon.c | 24 +- 12 files changed, 1009 insertions(+), 1257 deletions(-) -- 2.20.1 ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v10 0/2] powerpc/64s: reimplement book3s idle code in C @ 2019-04-28 11:45 ` Nicholas Piggin 0 siblings, 0 replies; 10+ messages in thread From: Nicholas Piggin @ 2019-04-28 11:45 UTC (permalink / raw) To: linuxppc-dev; +Cc: Gautham R . Shenoy, kvm-ppc, Nicholas Piggin The KVM code is in better shape now, survives various testing I came up with, so should be ready for more review. I won't post it again with the KVM part split out unless significant changes are required there. As explained in the comments for patch 1, the split results in some intermediate KVM issues, but the split is supposed to make KVM review easier. Gautham I left your review tag, quite a lot of KVM changes since he reviewed it, but non-KVM patch is not much different. Let me know if I should drop it. Thanks, Nick Nicholas Piggin (2): powerpc/64s: reimplement book3s idle code in C powerpc/64s: KVM update for reimplement book3s idle code in C arch/powerpc/include/asm/cpuidle.h | 19 +- arch/powerpc/include/asm/paca.h | 40 +- arch/powerpc/include/asm/processor.h | 9 +- arch/powerpc/include/asm/reg.h | 8 +- arch/powerpc/kernel/asm-offsets.c | 18 - arch/powerpc/kernel/exceptions-64s.S | 23 +- arch/powerpc/kernel/idle_book3s.S | 1099 +++------------------- arch/powerpc/kernel/setup-common.c | 4 +- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 118 ++- arch/powerpc/platforms/powernv/idle.c | 902 ++++++++++++++---- arch/powerpc/platforms/powernv/subcore.c | 2 +- arch/powerpc/xmon/xmon.c | 24 +- 12 files changed, 1009 insertions(+), 1257 deletions(-) -- 2.20.1 ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v10 1/2] powerpc/64s: reimplement book3s idle code in C 2019-04-28 11:45 ` Nicholas Piggin @ 2019-04-28 11:45 ` Nicholas Piggin -1 siblings, 0 replies; 10+ messages in thread From: Nicholas Piggin @ 2019-04-28 11:45 UTC (permalink / raw) To: linuxppc-dev; +Cc: Gautham R . Shenoy, kvm-ppc, Nicholas Piggin Reimplement Book3S idle code in C, moving POWER7/8/9 implementation speific HV idle code to the powernv platform code. Book3S assembly stubs are kept in common code and used only to save the stack frame and non-volatile GPRs before executing architected idle instructions, and restoring the stack and reloading GPRs then returning to C after waking from idle. The complex logic dealing with threads and subcores, locking, SPRs, HMIs, timebase resync, etc., is all done in C which makes it more maintainable. This is not a strict 1:1 translation to C code, there are some significant differences: - Idle wakeup no longer uses the ->cpu_restore call to reinit SPRs, but saves and restores them itself. - The optimisation where EC=ESL=0 idle modes did not have to save GPRs or change MSR is restored, because it's now simple to do. ESL=1 sleeps that do not lose GPRs can use this optimization too. - KVM secondary entry and cede is now more of a call/return style rather than branchy. nap_state_lost is not required because KVM always returns via NVGPR restoring path. - KVM secondary wakeup from offline sequence is moved entirely into the offline wakeup, which avoids a hwsync in the normal idle wakeup path. Performance measured with context switch ping-pong on different threads or cores, is possibly improved a small amount, 1-3% depending on stop state and core vs thread test for shallow states. Deep states it's in the noise compared with other latencies. Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Notes: - I've broken the KVM code into the second patch just for review. The first patch makes KVM kind-of work with its existing design in the new idle code. The problem is the kvm_start_guest case branches out from the low level asm, which now no longer fixes up SPRs. Guests will somewhat run with deep idle states disabled for offline. Rather than a significant rework of the code to make old-KVM work with new-idle code that would need testing and review and then gets undone by the next patch, I have just broken it up like this for hopefully easier review of the KVM parts. Patches can be squashed together before upstream merge. - P9 restores some of the PMU SPRs, but not others, and P8 only zeroes them. There are improvmets to be made to SPR save restore policies and documentation, but this first pass tries to keep things as they were. More work likely needs to be done here. Left to do: - Test actual POWER7 hardware. Will check about that tomorrow. Since v9: - Fix ELFv1 build error. - Port to powerpc next. - Test POWER8 and POWER9 online/offline - Test POWER8 and POWER9 KVM guests with threads, combinations of MMU modes in guest and host, indep threads mode, etc. --- arch/powerpc/include/asm/cpuidle.h | 19 +- arch/powerpc/include/asm/paca.h | 41 +- arch/powerpc/include/asm/processor.h | 9 +- arch/powerpc/include/asm/reg.h | 8 +- arch/powerpc/kernel/asm-offsets.c | 17 - arch/powerpc/kernel/exceptions-64s.S | 25 +- arch/powerpc/kernel/idle_book3s.S | 1097 +++------------------- arch/powerpc/kernel/setup-common.c | 4 +- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 6 +- arch/powerpc/platforms/powernv/idle.c | 887 +++++++++++++---- arch/powerpc/platforms/powernv/subcore.c | 2 +- arch/powerpc/xmon/xmon.c | 25 +- 12 files changed, 941 insertions(+), 1199 deletions(-) diff --git a/arch/powerpc/include/asm/cpuidle.h b/arch/powerpc/include/asm/cpuidle.h index 43e5f31fe64d..9844b3ded187 100644 --- a/arch/powerpc/include/asm/cpuidle.h +++ b/arch/powerpc/include/asm/cpuidle.h @@ -27,10 +27,11 @@ * the THREAD_WINKLE_BITS are set, which indicate which threads have not * yet woken from the winkle state. */ -#define PNV_CORE_IDLE_LOCK_BIT 0x10000000 +#define NR_PNV_CORE_IDLE_LOCK_BIT 28 +#define PNV_CORE_IDLE_LOCK_BIT (1ULL << NR_PNV_CORE_IDLE_LOCK_BIT) +#define PNV_CORE_IDLE_WINKLE_COUNT_SHIFT 16 #define PNV_CORE_IDLE_WINKLE_COUNT 0x00010000 -#define PNV_CORE_IDLE_WINKLE_COUNT_ALL_BIT 0x00080000 #define PNV_CORE_IDLE_WINKLE_COUNT_BITS 0x000F0000 #define PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT 8 #define PNV_CORE_IDLE_THREAD_WINKLE_BITS 0x0000FF00 @@ -68,16 +69,6 @@ #define ERR_DEEP_STATE_ESL_MISMATCH -2 #ifndef __ASSEMBLY__ -/* Additional SPRs that need to be saved/restored during stop */ -struct stop_sprs { - u64 pid; - u64 ldbar; - u64 fscr; - u64 hfscr; - u64 mmcr1; - u64 mmcr2; - u64 mmcra; -}; #define PNV_IDLE_NAME_LEN 16 struct pnv_idle_states_t { @@ -92,10 +83,6 @@ struct pnv_idle_states_t { extern struct pnv_idle_states_t *pnv_idle_states; extern int nr_pnv_idle_states; -extern u32 pnv_fastsleep_workaround_at_entry[]; -extern u32 pnv_fastsleep_workaround_at_exit[]; - -extern u64 pnv_first_deep_stop_state; unsigned long pnv_cpu_offline(unsigned int cpu); int validate_psscr_val_mask(u64 *psscr_val, u64 *psscr_mask, u32 flags); diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index e843bc5d1a0f..e55dedd7ee3e 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -173,8 +173,8 @@ struct paca_struct { u8 irq_happened; /* irq happened while soft-disabled */ u8 io_sync; /* writel() needs spin_unlock sync */ u8 irq_work_pending; /* IRQ_WORK interrupt while soft-disable */ - u8 nap_state_lost; /* NV GPR values lost in power7_idle */ #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + u8 nap_state_lost; /* NV GPR values lost in power7_idle */ u8 pmcregs_in_use; /* pseries puts this in lppaca */ #endif u64 sprg_vdso; /* Saved user-visible sprg */ @@ -183,23 +183,28 @@ struct paca_struct { #endif #ifdef CONFIG_PPC_POWERNV - /* Per-core mask tracking idle threads and a lock bit-[L][TTTTTTTT] */ - u32 *core_idle_state_ptr; - u8 thread_idle_state; /* PNV_THREAD_RUNNING/NAP/SLEEP */ - /* Mask to indicate thread id in core */ - u8 thread_mask; - /* Mask to denote subcore sibling threads */ - u8 subcore_sibling_mask; - /* Flag to request this thread not to stop */ - atomic_t dont_stop; - /* The PSSCR value that the kernel requested before going to stop */ - u64 requested_psscr; - - /* - * Save area for additional SPRs that need to be - * saved/restored during cpuidle stop. - */ - struct stop_sprs stop_sprs; + /* PowerNV idle fields */ + /* PNV_CORE_IDLE_* bits, all siblings work on thread 0 paca */ + unsigned long idle_state; + union { + /* P7/P8 specific fields */ + struct { + /* PNV_THREAD_RUNNING/NAP/SLEEP */ + u8 thread_idle_state; + /* Mask to denote subcore sibling threads */ + u8 subcore_sibling_mask; + }; + + /* P9 specific fields */ + struct { +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + /* The PSSCR value that the kernel requested before going to stop */ + u64 requested_psscr; + /* Flag to request this thread not to stop */ + atomic_t dont_stop; +#endif + }; + }; #endif #ifdef CONFIG_PPC_BOOK3S_64 diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index 540949b397d4..706ac5df546f 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -414,14 +414,17 @@ static inline unsigned long get_clean_sp(unsigned long sp, int is_32) } #endif +/* asm stubs */ +extern unsigned long isa300_idle_stop_noloss(unsigned long psscr_val); +extern unsigned long isa300_idle_stop_mayloss(unsigned long psscr_val); +extern unsigned long isa206_idle_insn_mayloss(unsigned long type); + extern unsigned long cpuidle_disable; enum idle_boot_override {IDLE_NO_OVERRIDE = 0, IDLE_POWERSAVE_OFF}; extern int powersave_nap; /* set if nap mode can be used in idle loop */ -extern unsigned long power7_idle_insn(unsigned long type); /* PNV_THREAD_NAP/etc*/ + extern void power7_idle_type(unsigned long type); -extern unsigned long power9_idle_stop(unsigned long psscr_val); -extern unsigned long power9_offline_stop(unsigned long psscr_val); extern void power9_idle_type(unsigned long stop_psscr_val, unsigned long stop_psscr_mask); diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index c5b2aff0ce8e..10caa145f98b 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -168,6 +168,7 @@ #define PSSCR_ESL 0x00200000 /* Enable State Loss */ #define PSSCR_SD 0x00400000 /* Status Disable */ #define PSSCR_PLS 0xf000000000000000 /* Power-saving Level Status */ +#define PSSCR_PLS_SHIFT 60 #define PSSCR_GUEST_VIS 0xf0000000000003ffUL /* Guest-visible PSSCR fields */ #define PSSCR_FAKE_SUSPEND 0x00000400 /* Fake-suspend bit (P9 DD2.2) */ #define PSSCR_FAKE_SUSPEND_LG 10 /* Fake-suspend bit position */ @@ -758,10 +759,9 @@ #define SRR1_WAKERESET 0x00100000 /* System reset */ #define SRR1_WAKEHDBELL 0x000c0000 /* Hypervisor doorbell on P8 */ #define SRR1_WAKESTATE 0x00030000 /* Powersave exit mask [46:47] */ -#define SRR1_WS_DEEPEST 0x00030000 /* Some resources not maintained, - * may not be recoverable */ -#define SRR1_WS_DEEPER 0x00020000 /* Some resources not maintained */ -#define SRR1_WS_DEEP 0x00010000 /* All resources maintained */ +#define SRR1_WS_HVLOSS 0x00030000 /* HV resources not maintained */ +#define SRR1_WS_GPRLOSS 0x00020000 /* GPRs not maintained */ +#define SRR1_WS_NOLOSS 0x00010000 /* All resources maintained */ #define SRR1_PROGTM 0x00200000 /* TM Bad Thing */ #define SRR1_PROGFPE 0x00100000 /* Floating Point Enabled */ #define SRR1_PROGILL 0x00080000 /* Illegal instruction */ diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 60b82198de7c..a14a77bc4243 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -773,23 +773,6 @@ int main(void) OFFSET(VCPU_TIMING_LAST_ENTER_TBL, kvm_vcpu, arch.timing_last_enter.tv32.tbl); #endif -#ifdef CONFIG_PPC_POWERNV - OFFSET(PACA_CORE_IDLE_STATE_PTR, paca_struct, core_idle_state_ptr); - OFFSET(PACA_THREAD_IDLE_STATE, paca_struct, thread_idle_state); - OFFSET(PACA_THREAD_MASK, paca_struct, thread_mask); - OFFSET(PACA_SUBCORE_SIBLING_MASK, paca_struct, subcore_sibling_mask); - OFFSET(PACA_REQ_PSSCR, paca_struct, requested_psscr); - OFFSET(PACA_DONT_STOP, paca_struct, dont_stop); -#define STOP_SPR(x, f) OFFSET(x, paca_struct, stop_sprs.f) - STOP_SPR(STOP_PID, pid); - STOP_SPR(STOP_LDBAR, ldbar); - STOP_SPR(STOP_FSCR, fscr); - STOP_SPR(STOP_HFSCR, hfscr); - STOP_SPR(STOP_MMCR1, mmcr1); - STOP_SPR(STOP_MMCR2, mmcr2); - STOP_SPR(STOP_MMCRA, mmcra); -#endif - DEFINE(PPC_DBELL_SERVER, PPC_DBELL_SERVER); DEFINE(PPC_DBELL_MSGTYPE, PPC_DBELL_MSGTYPE); diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index bedd89438827..671c256da167 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -121,7 +121,7 @@ EXC_VIRT_NONE(0x4000, 0x100) mfspr r10,SPRN_SRR1 ; \ rlwinm. r10,r10,47-31,30,31 ; \ beq- 1f ; \ - cmpwi cr3,r10,2 ; \ + cmpwi cr1,r10,2 ; \ BRANCH_TO_C000(r10, system_reset_idle_common) ; \ 1: \ KVMTEST_PR(n) ; \ @@ -145,8 +145,13 @@ TRAMP_KVM(PACA_EXNMI, 0x100) #ifdef CONFIG_PPC_P7_NAP EXC_COMMON_BEGIN(system_reset_idle_common) - mfspr r12,SPRN_SRR1 - b pnv_powersave_wakeup + mfspr r3,SPRN_SRR1 +#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE + /* this bltlr could be moved before the branch_to, and the + * branch_to could maybe go straight to idle_return */ + bltlr cr1 /* no state loss, return to idle caller */ +#endif + b idle_return_gpr_loss #endif /* @@ -429,17 +434,19 @@ EXC_COMMON_BEGIN(machine_check_idle_common) * Then decrement MCE nesting after finishing with the stack. */ ld r3,_MSR(r1) + ld r4,_LINK(r1) lhz r11,PACA_IN_MCE(r13) subi r11,r11,1 sth r11,PACA_IN_MCE(r13) - /* Turn off the RI bit because SRR1 is used by idle wakeup code. */ - /* Recoverability could be improved by reducing the use of SRR1. */ - li r11,0 - mtmsrd r11,1 - - b pnv_powersave_wakeup_mce + mtlr r4 + rlwinm r10,r3,47-31,30,31 + cmpwi cr1,r10,2 +#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE + bltlr cr1 /* no state loss, return to idle caller */ +#endif + b idle_return_gpr_loss #endif /* * Handle machine check early in real mode. We come here with diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index 4a860d3b9229..0fb2eb731a29 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -1,539 +1,98 @@ /* - * This file contains idle entry/exit functions for POWER7, - * POWER8 and POWER9 CPUs. + * Copyright 2018, IBM Corporation. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. + * + * This file contains general idle entry/exit functions to save + * and restore stack and NVGPRs which allows C code to call idle + * states that lose GPRs, and it will return transparently with + * SRR1 wakeup reason return value. + * + * The platform / CPU caller must ensure SPRs and any other non-GPR + * state is saved and restored correctly, handle KVM, interrupts, etc. */ -#include <linux/threads.h> -#include <asm/processor.h> -#include <asm/page.h> -#include <asm/cputable.h> -#include <asm/thread_info.h> #include <asm/ppc_asm.h> #include <asm/asm-offsets.h> #include <asm/ppc-opcode.h> -#include <asm/hw_irq.h> -#include <asm/kvm_book3s_asm.h> -#include <asm/opal.h> #include <asm/cpuidle.h> -#include <asm/exception-64s.h> -#include <asm/book3s/64/mmu-hash.h> -#include <asm/mmu.h> -#include <asm/asm-compat.h> -#include <asm/feature-fixups.h> - -#undef DEBUG - -/* - * Use unused space in the interrupt stack to save and restore - * registers for winkle support. - */ -#define _MMCR0 GPR0 -#define _SDR1 GPR3 -#define _PTCR GPR3 -#define _RPR GPR4 -#define _SPURR GPR5 -#define _PURR GPR6 -#define _TSCR GPR7 -#define _DSCR GPR8 -#define _AMOR GPR9 -#define _WORT GPR10 -#define _WORC GPR11 -#define _LPCR GPR12 - -#define PSSCR_EC_ESL_MASK_SHIFTED (PSSCR_EC | PSSCR_ESL) >> 16 - - .text +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE +#include <asm/kvm_book3s_asm.h> +#endif /* - * Used by threads before entering deep idle states. Saves SPRs - * in interrupt stack frame - */ -save_sprs_to_stack: - /* - * Note all register i.e per-core, per-subcore or per-thread is saved - * here since any thread in the core might wake up first - */ -BEGIN_FTR_SECTION - /* - * Note - SDR1 is dropped in Power ISA v3. Hence not restoring - * SDR1 here - */ - mfspr r3,SPRN_PTCR - std r3,_PTCR(r1) - mfspr r3,SPRN_LPCR - std r3,_LPCR(r1) -FTR_SECTION_ELSE - mfspr r3,SPRN_SDR1 - std r3,_SDR1(r1) -ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300) - mfspr r3,SPRN_RPR - std r3,_RPR(r1) - mfspr r3,SPRN_SPURR - std r3,_SPURR(r1) - mfspr r3,SPRN_PURR - std r3,_PURR(r1) - mfspr r3,SPRN_TSCR - std r3,_TSCR(r1) - mfspr r3,SPRN_DSCR - std r3,_DSCR(r1) - mfspr r3,SPRN_AMOR - std r3,_AMOR(r1) - mfspr r3,SPRN_WORT - std r3,_WORT(r1) - mfspr r3,SPRN_WORC - std r3,_WORC(r1) -/* - * On POWER9, there are idle states such as stop4, invoked via cpuidle, - * that lose hypervisor resources. In such cases, we need to save - * additional SPRs before entering those idle states so that they can - * be restored to their older values on wakeup from the idle state. + * Desired PSSCR in r3 * - * On POWER8, the only such deep idle state is winkle which is used - * only in the context of CPU-Hotplug, where these additional SPRs are - * reinitiazed to a sane value. Hence there is no need to save/restore - * these SPRs. - */ -BEGIN_FTR_SECTION - blr -END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) - -power9_save_additional_sprs: - mfspr r3, SPRN_PID - mfspr r4, SPRN_LDBAR - std r3, STOP_PID(r13) - std r4, STOP_LDBAR(r13) - - mfspr r3, SPRN_FSCR - mfspr r4, SPRN_HFSCR - std r3, STOP_FSCR(r13) - std r4, STOP_HFSCR(r13) - - mfspr r3, SPRN_MMCRA - mfspr r4, SPRN_MMCR0 - std r3, STOP_MMCRA(r13) - std r4, _MMCR0(r1) - - mfspr r3, SPRN_MMCR1 - mfspr r4, SPRN_MMCR2 - std r3, STOP_MMCR1(r13) - std r4, STOP_MMCR2(r13) - blr - -power9_restore_additional_sprs: - ld r3,_LPCR(r1) - ld r4, STOP_PID(r13) - mtspr SPRN_LPCR,r3 - mtspr SPRN_PID, r4 - - ld r3, STOP_LDBAR(r13) - ld r4, STOP_FSCR(r13) - mtspr SPRN_LDBAR, r3 - mtspr SPRN_FSCR, r4 - - ld r3, STOP_HFSCR(r13) - ld r4, STOP_MMCRA(r13) - mtspr SPRN_HFSCR, r3 - mtspr SPRN_MMCRA, r4 - - ld r3, _MMCR0(r1) - ld r4, STOP_MMCR1(r13) - mtspr SPRN_MMCR0, r3 - mtspr SPRN_MMCR1, r4 - - ld r3, STOP_MMCR2(r13) - ld r4, PACA_SPRG_VDSO(r13) - mtspr SPRN_MMCR2, r3 - mtspr SPRN_SPRG3, r4 - blr - -/* - * Used by threads when the lock bit of core_idle_state is set. - * Threads will spin in HMT_LOW until the lock bit is cleared. - * r14 - pointer to core_idle_state - * r15 - used to load contents of core_idle_state - * r9 - used as a temporary variable + * No state will be lost regardless of wakeup mechanism (interrupt or NIA). + * + * An EC=0 type wakeup will return with a value of 0. SRESET wakeup (which can + * happen with xscom SRESET and possibly MCE) may clobber volatiles except LR, + * and must blr, to return to caller with r3 set according to caller's expected + * return code (for Book3S/64 that is SRR1). */ - -core_idle_lock_held: - HMT_LOW -3: lwz r15,0(r14) - andis. r15,r15,PNV_CORE_IDLE_LOCK_BIT@h - bne 3b - HMT_MEDIUM - lwarx r15,0,r14 - andis. r9,r15,PNV_CORE_IDLE_LOCK_BIT@h - bne- core_idle_lock_held +_GLOBAL(isa300_idle_stop_noloss) + mtspr SPRN_PSSCR,r3 + PPC_STOP + li r3,0 blr -/* Reuse some unused pt_regs slots for AMR/IAMR/UAMOR/UAMOR */ -#define PNV_POWERSAVE_AMR _TRAP -#define PNV_POWERSAVE_IAMR _DAR -#define PNV_POWERSAVE_UAMOR _DSISR -#define PNV_POWERSAVE_AMOR RESULT - /* - * Pass requested state in r3: - * r3 - PNV_THREAD_NAP/SLEEP/WINKLE in POWER8 - * - Requested PSSCR value in POWER9 + * Desired PSSCR in r3 + * + * GPRs may be lost, so they are saved here. Wakeup is by interrupt only. + * The SRESET wakeup returns to this function's caller by calling + * idle_return_gpr_loss with r3 set to desired return value. + * + * A wakeup without GPR loss may alteratively be handled as in + * isa300_idle_stop_noloss and blr directly, as an optimisation. * - * Address of idle handler to branch to in realmode in r4 + * The caller is responsible for saving/restoring SPRs, MSR, timebase, + * etc. */ -pnv_powersave_common: - /* Use r3 to pass state nap/sleep/winkle */ - /* NAP is a state loss, we create a regs frame on the - * stack, fill it up with the state we care about and - * stick a pointer to it in PACAR1. We really only - * need to save PC, some CR bits and the NV GPRs, - * but for now an interrupt frame will do. - */ - mtctr r4 - - mflr r0 - std r0,16(r1) - stdu r1,-INT_FRAME_SIZE(r1) - std r0,_LINK(r1) - std r0,_NIP(r1) - - /* We haven't lost state ... yet */ - li r0,0 - stb r0,PACA_NAPSTATELOST(r13) - - /* Continue saving state */ - SAVE_GPR(2, r1) - SAVE_NVGPRS(r1) - -BEGIN_FTR_SECTION - mfspr r4, SPRN_AMR - mfspr r5, SPRN_IAMR - mfspr r6, SPRN_UAMOR - std r4, PNV_POWERSAVE_AMR(r1) - std r5, PNV_POWERSAVE_IAMR(r1) - std r6, PNV_POWERSAVE_UAMOR(r1) -BEGIN_FTR_SECTION_NESTED(42) - mfspr r7, SPRN_AMOR - std r7, PNV_POWERSAVE_AMOR(r1) -END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE, 42) -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) - - mfcr r5 - std r5,_CCR(r1) +_GLOBAL(isa300_idle_stop_mayloss) + mtspr SPRN_PSSCR,r3 std r1,PACAR1(r13) - -BEGIN_FTR_SECTION - /* - * POWER9 does not require real mode to stop, and presently does not - * set hwthread_state for KVM (threads don't share MMU context), so - * we can remain in virtual mode for this. - */ - bctr -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) - /* - * POWER8 - * Go to real mode to do the nap, as required by the architecture. - * Also, we need to be in real mode before setting hwthread_state, - * because as soon as we do that, another thread can switch - * the MMU context to the guest. - */ - LOAD_REG_IMMEDIATE(r7, MSR_IDLE) - mtmsrd r7,0 - bctr - -/* - * This is the sequence required to execute idle instructions, as - * specified in ISA v2.07 (and earlier). MSR[IR] and MSR[DR] must be 0. - */ -#define IDLE_STATE_ENTER_SEQ_NORET(IDLE_INST) \ - /* Magic NAP/SLEEP/WINKLE mode enter sequence */ \ - std r0,0(r1); \ - ptesync; \ - ld r0,0(r1); \ -236: cmpd cr0,r0,r0; \ - bne 236b; \ - IDLE_INST; - - - .globl pnv_enter_arch207_idle_mode -pnv_enter_arch207_idle_mode: -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE - /* Tell KVM we're entering idle */ - li r4,KVM_HWTHREAD_IN_IDLE - /******************************************************/ - /* N O T E W E L L ! ! ! N O T E W E L L */ - /* The following store to HSTATE_HWTHREAD_STATE(r13) */ - /* MUST occur in real mode, i.e. with the MMU off, */ - /* and the MMU must stay off until we clear this flag */ - /* and test HSTATE_HWTHREAD_REQ(r13) in */ - /* pnv_powersave_wakeup in this file. */ - /* The reason is that another thread can switch the */ - /* MMU to a guest context whenever this flag is set */ - /* to KVM_HWTHREAD_IN_IDLE, and if the MMU was on, */ - /* that would potentially cause this thread to start */ - /* executing instructions from guest memory in */ - /* hypervisor mode, leading to a host crash or data */ - /* corruption, or worse. */ - /******************************************************/ - stb r4,HSTATE_HWTHREAD_STATE(r13) -#endif - stb r3,PACA_THREAD_IDLE_STATE(r13) - cmpwi cr3,r3,PNV_THREAD_SLEEP - bge cr3,2f - IDLE_STATE_ENTER_SEQ_NORET(PPC_NAP) - /* No return */ -2: - /* Sleep or winkle */ - lbz r7,PACA_THREAD_MASK(r13) - ld r14,PACA_CORE_IDLE_STATE_PTR(r13) - li r5,0 - beq cr3,3f - lis r5,PNV_CORE_IDLE_WINKLE_COUNT@h -3: -lwarx_loop1: - lwarx r15,0,r14 - - andis. r9,r15,PNV_CORE_IDLE_LOCK_BIT@h - bnel- core_idle_lock_held - - add r15,r15,r5 /* Add if winkle */ - andc r15,r15,r7 /* Clear thread bit */ - - andi. r9,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 or winkle */ - bgt cr3,enter_winkle - IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP) - -fastsleep_workaround_at_entry: - oris r15,r15,PNV_CORE_IDLE_LOCK_BIT@h - stwcx. r15,0,r14 - bne- lwarx_loop1 - isync - - /* Fast sleep workaround */ - li r3,1 - li r4,1 - bl opal_config_cpu_idle_state - - /* Unlock */ - xoris r15,r15,PNV_CORE_IDLE_LOCK_BIT@h - lwsync - stw r15,0(r14) - b common_enter - -enter_winkle: - bl save_sprs_to_stack - - IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE) - -/* - * r3 - PSSCR value corresponding to the requested stop state. - */ -power_enter_stop: -/* - * Check if we are executing the lite variant with ESL=EC=0 - */ - andis. r4,r3,PSSCR_EC_ESL_MASK_SHIFTED - clrldi r3,r3,60 /* r3 = Bits[60:63] = Requested Level (RL) */ - bne .Lhandle_esl_ec_set + mflr r4 + mfcr r5 + /* use stack red zone rather than a new frame for saving regs */ + std r2,-8*0(r1) + std r14,-8*1(r1) + std r15,-8*2(r1) + std r16,-8*3(r1) + std r17,-8*4(r1) + std r18,-8*5(r1) + std r19,-8*6(r1) + std r20,-8*7(r1) + std r21,-8*8(r1) + std r22,-8*9(r1) + std r23,-8*10(r1) + std r24,-8*11(r1) + std r25,-8*12(r1) + std r26,-8*13(r1) + std r27,-8*14(r1) + std r28,-8*15(r1) + std r29,-8*16(r1) + std r30,-8*17(r1) + std r31,-8*18(r1) + std r4,-8*19(r1) + std r5,-8*20(r1) + /* 168 bytes */ PPC_STOP - li r3,0 /* Since we didn't lose state, return 0 */ - std r3, PACA_REQ_PSSCR(r13) - - /* - * pnv_wakeup_noloss() expects r12 to contain the SRR1 value so - * it can determine if the wakeup reason is an HMI in - * CHECK_HMI_INTERRUPT. - * - * However, when we wakeup with ESL=0, SRR1 will not contain the wakeup - * reason, so there is no point setting r12 to SRR1. - * - * Further, we clear r12 here, so that we don't accidentally enter the - * HMI in pnv_wakeup_noloss() if the value of r12[42:45] == WAKE_HMI. - */ - li r12, 0 - b pnv_wakeup_noloss - -.Lhandle_esl_ec_set: -BEGIN_FTR_SECTION - /* - * POWER9 DD2.0 or earlier can incorrectly set PMAO when waking up after - * a state-loss idle. Saving and restoring MMCR0 over idle is a - * workaround. - */ - mfspr r4,SPRN_MMCR0 - std r4,_MMCR0(r1) -END_FTR_SECTION_IFCLR(CPU_FTR_POWER9_DD2_1) + b . /* catch bugs */ /* - * Check if the requested state is a deep idle state. - */ - LOAD_REG_ADDRBASE(r5,pnv_first_deep_stop_state) - ld r4,ADDROFF(pnv_first_deep_stop_state)(r5) - cmpd r3,r4 - bge .Lhandle_deep_stop - PPC_STOP /* Does not return (system reset interrupt) */ - -.Lhandle_deep_stop: -/* - * Entering deep idle state. - * Clear thread bit in PACA_CORE_IDLE_STATE, save SPRs to - * stack and enter stop - */ - lbz r7,PACA_THREAD_MASK(r13) - ld r14,PACA_CORE_IDLE_STATE_PTR(r13) - -lwarx_loop_stop: - lwarx r15,0,r14 - andis. r9,r15,PNV_CORE_IDLE_LOCK_BIT@h - bnel- core_idle_lock_held - andc r15,r15,r7 /* Clear thread bit */ - - stwcx. r15,0,r14 - bne- lwarx_loop_stop - isync - - bl save_sprs_to_stack - - PPC_STOP /* Does not return (system reset interrupt) */ - -/* - * Entered with MSR[EE]=0 and no soft-masked interrupts pending. - * r3 contains desired idle state (PNV_THREAD_NAP/SLEEP/WINKLE). - */ -_GLOBAL(power7_idle_insn) - /* Now check if user or arch enabled NAP mode */ - LOAD_REG_ADDR(r4, pnv_enter_arch207_idle_mode) - b pnv_powersave_common - -#define CHECK_HMI_INTERRUPT \ -BEGIN_FTR_SECTION_NESTED(66); \ - rlwinm r0,r12,45-31,0xf; /* extract wake reason field (P8) */ \ -FTR_SECTION_ELSE_NESTED(66); \ - rlwinm r0,r12,45-31,0xe; /* P7 wake reason field is 3 bits */ \ -ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 66); \ - cmpwi r0,0xa; /* Hypervisor maintenance ? */ \ - bne+ 20f; \ - /* Invoke opal call to handle hmi */ \ - ld r2,PACATOC(r13); \ - ld r1,PACAR1(r13); \ - std r3,ORIG_GPR3(r1); /* Save original r3 */ \ - li r3,0; /* NULL argument */ \ - bl hmi_exception_realmode; \ - nop; \ - ld r3,ORIG_GPR3(r1); /* Restore original r3 */ \ -20: nop; - -/* - * Entered with MSR[EE]=0 and no soft-masked interrupts pending. - * r3 contains desired PSSCR register value. + * Desired return value in r3 * - * Offline (CPU unplug) case also must notify KVM that the CPU is - * idle. - */ -_GLOBAL(power9_offline_stop) -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE - /* - * Tell KVM we're entering idle. - * This does not have to be done in real mode because the P9 MMU - * is independent per-thread. Some steppings share radix/hash mode - * between threads, but in that case KVM has a barrier sync in real - * mode before and after switching between radix and hash. - */ - li r4,KVM_HWTHREAD_IN_IDLE - stb r4,HSTATE_HWTHREAD_STATE(r13) -#endif - /* fall through */ - -_GLOBAL(power9_idle_stop) - std r3, PACA_REQ_PSSCR(r13) -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE -BEGIN_FTR_SECTION - sync - lwz r5, PACA_DONT_STOP(r13) - cmpwi r5, 0 - bne 1f -END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_XER_SO_BUG) -#endif - mtspr SPRN_PSSCR,r3 - LOAD_REG_ADDR(r4,power_enter_stop) - b pnv_powersave_common - /* No return */ -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE -1: - /* - * We get here when TM / thread reconfiguration bug workaround - * code wants to get the CPU into SMT4 mode, and therefore - * we are being asked not to stop. - */ - li r3, 0 - std r3, PACA_REQ_PSSCR(r13) - blr /* return 0 for wakeup cause / SRR1 value */ -#endif - -/* - * Called from machine check handler for powersave wakeups. - * Low level machine check processing has already been done. Now just - * go through the wake up path to get everything in order. + * The idle wakeup SRESET interrupt can call this after calling + * to return to the idle sleep function caller with r3 as the return code. * - * r3 - The original SRR1 value. - * Original SRR[01] have been clobbered. - * MSR_RI is clear. - */ -.global pnv_powersave_wakeup_mce -pnv_powersave_wakeup_mce: - /* Set cr3 for pnv_powersave_wakeup */ - rlwinm r11,r3,47-31,30,31 - cmpwi cr3,r11,2 - - /* - * Now put the original SRR1 with SRR1_WAKEMCE_RESVD as the wake - * reason into r12, which allows reuse of the system reset wakeup - * code without being mistaken for another type of wakeup. - */ - oris r12,r3,SRR1_WAKEMCE_RESVD@h - - b pnv_powersave_wakeup - -/* - * Called from reset vector for powersave wakeups. - * cr3 - set to gt if waking up with partial/complete hypervisor state loss - * r12 - SRR1 + * This must not be used if idle was entered via a _noloss function (use + * a simple blr instead). */ -.global pnv_powersave_wakeup -pnv_powersave_wakeup: - ld r2, PACATOC(r13) - -BEGIN_FTR_SECTION - bl pnv_restore_hyp_resource_arch300 -FTR_SECTION_ELSE - bl pnv_restore_hyp_resource_arch207 -ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300) - - li r0,PNV_THREAD_RUNNING - stb r0,PACA_THREAD_IDLE_STATE(r13) /* Clear thread state */ - - mr r3,r12 - +_GLOBAL(idle_return_gpr_loss) #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE lbz r0,HSTATE_HWTHREAD_STATE(r13) cmpwi r0,KVM_HWTHREAD_IN_KERNEL @@ -547,449 +106,105 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300) beq 1f b kvm_start_guest 1: + lbz r0,PACA_NAPSTATELOST(r13) + cmpwi r0,0 + bne 2f + bltlr cr1 +2: #endif - - /* Return SRR1 from power7_nap() */ - blt cr3,pnv_wakeup_noloss - b pnv_wakeup_loss + ld r1,PACAR1(r13) + ld r4,-8*19(r1) + ld r5,-8*20(r1) + mtlr r4 + mtcr r5 + /* + * KVM nap requires r2 to be saved, rather than just restoring it + * from PACATOC. This could be avoided for that less common case + * if KVM saved its r2. + */ + ld r2,-8*0(r1) + ld r14,-8*1(r1) + ld r15,-8*2(r1) + ld r16,-8*3(r1) + ld r17,-8*4(r1) + ld r18,-8*5(r1) + ld r19,-8*6(r1) + ld r20,-8*7(r1) + ld r21,-8*8(r1) + ld r22,-8*9(r1) + ld r23,-8*10(r1) + ld r24,-8*11(r1) + ld r25,-8*12(r1) + ld r26,-8*13(r1) + ld r27,-8*14(r1) + ld r28,-8*15(r1) + ld r29,-8*16(r1) + ld r30,-8*17(r1) + ld r31,-8*18(r1) + blr /* - * Check whether we have woken up with hypervisor state loss. - * If yes, restore hypervisor state and return back to link. + * This is the sequence required to execute idle instructions, as + * specified in ISA v2.07 (and earlier). MSR[IR] and MSR[DR] must be 0. * - * cr3 - set to gt if waking up with partial/complete hypervisor state loss + * The 0(r1) slot is used to save r2 in isa206, so use that here. */ -pnv_restore_hyp_resource_arch300: - /* - * Workaround for POWER9, if we lost resources, the ERAT - * might have been mixed up and needs flushing. We also need - * to reload MMCR0 (see comment above). We also need to set - * then clear bit 60 in MMCRA to ensure the PMU starts running. - */ - blt cr3,1f -BEGIN_FTR_SECTION - PPC_INVALIDATE_ERAT - ld r1,PACAR1(r13) - ld r4,_MMCR0(r1) - mtspr SPRN_MMCR0,r4 -END_FTR_SECTION_IFCLR(CPU_FTR_POWER9_DD2_1) - mfspr r4,SPRN_MMCRA - ori r4,r4,(1 << (63-60)) - mtspr SPRN_MMCRA,r4 - xori r4,r4,(1 << (63-60)) - mtspr SPRN_MMCRA,r4 -1: - /* - * POWER ISA 3. Use PSSCR to determine if we - * are waking up from deep idle state - */ - LOAD_REG_ADDRBASE(r5,pnv_first_deep_stop_state) - ld r4,ADDROFF(pnv_first_deep_stop_state)(r5) - - /* - * 0-3 bits correspond to Power-Saving Level Status - * which indicates the idle state we are waking up from - */ - mfspr r5, SPRN_PSSCR - rldicl r5,r5,4,60 - li r0, 0 /* clear requested_psscr to say we're awake */ - std r0, PACA_REQ_PSSCR(r13) - cmpd cr4,r5,r4 - bge cr4,pnv_wakeup_tb_loss /* returns to caller */ - - blr /* Waking up without hypervisor state loss. */ - -/* Same calling convention as arch300 */ -pnv_restore_hyp_resource_arch207: - /* - * POWER ISA 2.07 or less. - * Check if we slept with sleep or winkle. - */ - lbz r4,PACA_THREAD_IDLE_STATE(r13) - cmpwi cr2,r4,PNV_THREAD_NAP - bgt cr2,pnv_wakeup_tb_loss /* Either sleep or Winkle */ - - /* - * We fall through here if PACA_THREAD_IDLE_STATE shows we are waking - * up from nap. At this stage CR3 shouldn't contains 'gt' since that - * indicates we are waking with hypervisor state loss from nap. - */ - bgt cr3,. - - blr /* Waking up without hypervisor state loss */ +#define IDLE_STATE_ENTER_SEQ_NORET(IDLE_INST) \ + /* Magic NAP/SLEEP/WINKLE mode enter sequence */ \ + std r2,0(r1); \ + ptesync; \ + ld r2,0(r1); \ +236: cmpd cr0,r2,r2; \ + bne 236b; \ + IDLE_INST; \ + b . /* catch bugs */ /* - * Called if waking up from idle state which can cause either partial or - * complete hyp state loss. - * In POWER8, called if waking up from fastsleep or winkle - * In POWER9, called if waking up from stop state >= pnv_first_deep_stop_state + * Desired instruction type in r3 * - * r13 - PACA - * cr3 - gt if waking up with partial/complete hypervisor state loss + * GPRs may be lost, so they are saved here. Wakeup is by interrupt only. + * The SRESET wakeup returns to this function's caller by calling + * idle_return_gpr_loss with r3 set to desired return value. * - * If ISA300: - * cr4 - gt or eq if waking up from complete hypervisor state loss. + * A wakeup without GPR loss may alteratively be handled as in + * isa300_idle_stop_noloss and blr directly, as an optimisation. * - * If ISA207: - * r4 - PACA_THREAD_IDLE_STATE - */ -pnv_wakeup_tb_loss: - ld r1,PACAR1(r13) - /* - * Before entering any idle state, the NVGPRs are saved in the stack. - * If there was a state loss, or PACA_NAPSTATELOST was set, then the - * NVGPRs are restored. If we are here, it is likely that state is lost, - * but not guaranteed -- neither ISA207 nor ISA300 tests to reach - * here are the same as the test to restore NVGPRS: - * PACA_THREAD_IDLE_STATE test for ISA207, PSSCR test for ISA300, - * and SRR1 test for restoring NVGPRs. - * - * We are about to clobber NVGPRs now, so set NAPSTATELOST to - * guarantee they will always be restored. This might be tightened - * with careful reading of specs (particularly for ISA300) but this - * is already a slow wakeup path and it's simpler to be safe. - */ - li r0,1 - stb r0,PACA_NAPSTATELOST(r13) - - /* - * - * Save SRR1 and LR in NVGPRs as they might be clobbered in - * opal_call() (called in CHECK_HMI_INTERRUPT). SRR1 is required - * to determine the wakeup reason if we branch to kvm_start_guest. LR - * is required to return back to reset vector after hypervisor state - * restore is complete. - */ - mr r19,r12 - mr r18,r4 - mflr r17 -BEGIN_FTR_SECTION - CHECK_HMI_INTERRUPT -END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) - - ld r14,PACA_CORE_IDLE_STATE_PTR(r13) - lbz r7,PACA_THREAD_MASK(r13) - - /* - * Take the core lock to synchronize against other threads. - * - * 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. - */ -1: - lwarx r15,0,r14 - andis. r9,r15,PNV_CORE_IDLE_LOCK_BIT@h - bnel- core_idle_lock_held - oris r15,r15,PNV_CORE_IDLE_LOCK_BIT@h - stwcx. r15,0,r14 - bne- 1b - isync - - andi. r9,r15,PNV_CORE_IDLE_THREAD_BITS - cmpwi cr2,r9,0 - - /* - * At this stage - * cr2 - eq if first thread to wakeup in core - * cr3- gt if waking up with partial/complete hypervisor state loss - * ISA300: - * cr4 - gt or eq if waking up from complete hypervisor state loss. - */ - -BEGIN_FTR_SECTION - /* - * Were we in winkle? - * If yes, check if all threads were in winkle, decrement our - * winkle count, set all thread winkle bits if all were in winkle. - * Check if our thread has a winkle bit set, and set cr4 accordingly - * (to match ISA300, above). Pseudo-code for core idle state - * transitions for ISA207 is as follows (everything happens atomically - * due to store conditional and/or lock bit): - * - * nap_idle() { } - * nap_wake() { } - * - * sleep_idle() - * { - * core_idle_state &= ~thread_in_core - * } - * - * sleep_wake() - * { - * bool first_in_core, first_in_subcore; - * - * first_in_core = (core_idle_state & IDLE_THREAD_BITS) == 0; - * first_in_subcore = (core_idle_state & SUBCORE_SIBLING_MASK) == 0; - * - * core_idle_state |= thread_in_core; - * } - * - * winkle_idle() - * { - * core_idle_state &= ~thread_in_core; - * core_idle_state += 1 << WINKLE_COUNT_SHIFT; - * } - * - * winkle_wake() - * { - * bool first_in_core, first_in_subcore, winkle_state_lost; - * - * first_in_core = (core_idle_state & IDLE_THREAD_BITS) == 0; - * first_in_subcore = (core_idle_state & SUBCORE_SIBLING_MASK) == 0; - * - * core_idle_state |= thread_in_core; - * - * if ((core_idle_state & WINKLE_MASK) == (8 << WINKLE_COUNT_SIHFT)) - * core_idle_state |= THREAD_WINKLE_BITS; - * core_idle_state -= 1 << WINKLE_COUNT_SHIFT; - * - * winkle_state_lost = core_idle_state & - * (thread_in_core << WINKLE_THREAD_SHIFT); - * core_idle_state &= ~(thread_in_core << WINKLE_THREAD_SHIFT); - * } - * - */ - cmpwi r18,PNV_THREAD_WINKLE - bne 2f - andis. r9,r15,PNV_CORE_IDLE_WINKLE_COUNT_ALL_BIT@h - subis r15,r15,PNV_CORE_IDLE_WINKLE_COUNT@h - beq 2f - ori r15,r15,PNV_CORE_IDLE_THREAD_WINKLE_BITS /* all were winkle */ -2: - /* Shift thread bit to winkle mask, then test if this thread is set, - * and remove it from the winkle bits */ - slwi r8,r7,8 - and r8,r8,r15 - andc r15,r15,r8 - cmpwi cr4,r8,1 /* cr4 will be gt if our bit is set, lt if not */ - - lbz r4,PACA_SUBCORE_SIBLING_MASK(r13) - and r4,r4,r15 - cmpwi r4,0 /* Check if first in subcore */ - - or r15,r15,r7 /* Set thread bit */ - beq first_thread_in_subcore -END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) - - or r15,r15,r7 /* Set thread bit */ - beq cr2,first_thread_in_core - - /* Not first thread in core or subcore to wake up */ - b clear_lock - -first_thread_in_subcore: - /* - * If waking up from sleep, subcore state is not lost. Hence - * skip subcore state restore - */ - blt cr4,subcore_state_restored - - /* Restore per-subcore state */ - ld r4,_SDR1(r1) - mtspr SPRN_SDR1,r4 - - ld r4,_RPR(r1) - mtspr SPRN_RPR,r4 - ld r4,_AMOR(r1) - mtspr SPRN_AMOR,r4 - -subcore_state_restored: - /* - * Check if the thread is also the first thread in the core. If not, - * skip to clear_lock. - */ - bne cr2,clear_lock - -first_thread_in_core: - - /* - * First thread in the core waking up from any state which can cause - * partial or complete hypervisor state loss. 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 if the platform does not have fastsleep or does not - * require the workaround. Patching will be performed during the - * discovery of idle-states. - */ -.global pnv_fastsleep_workaround_at_exit -pnv_fastsleep_workaround_at_exit: - b fastsleep_workaround_at_exit - -timebase_resync: - /* - * Use cr3 which indicates that we are waking up with atleast partial - * hypervisor state loss to determine if TIMEBASE RESYNC is needed. - */ - ble cr3,.Ltb_resynced - /* Time base re-sync */ - bl opal_resync_timebase; - /* - * If waking up from sleep (POWER8), per core state - * is not lost, skip to clear_lock. - */ -.Ltb_resynced: - blt cr4,clear_lock - - /* - * First thread in the core to wake up and its waking up with - * complete hypervisor state loss. Restore per core hypervisor - * state. - */ -BEGIN_FTR_SECTION - ld r4,_PTCR(r1) - mtspr SPRN_PTCR,r4 - ld r4,_RPR(r1) - mtspr SPRN_RPR,r4 - ld r4,_AMOR(r1) - mtspr SPRN_AMOR,r4 -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) - - ld r4,_TSCR(r1) - mtspr SPRN_TSCR,r4 - ld r4,_WORC(r1) - mtspr SPRN_WORC,r4 - -clear_lock: - xoris r15,r15,PNV_CORE_IDLE_LOCK_BIT@h - lwsync - stw r15,0(r14) - -common_exit: - /* - * Common to all threads. - * - * If waking up from sleep, hypervisor state is not lost. Hence - * skip hypervisor state restore. - */ - blt cr4,hypervisor_state_restored - - /* Waking up from winkle */ - -BEGIN_MMU_FTR_SECTION - b no_segments -END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX) - /* Restore SLB from PACA */ - ld r8,PACA_SLBSHADOWPTR(r13) - - .rept SLB_NUM_BOLTED - li r3, SLBSHADOW_SAVEAREA - LDX_BE r5, r8, r3 - addi r3, r3, 8 - LDX_BE r6, r8, r3 - andis. r7,r5,SLB_ESID_V@h - beq 1f - slbmte r6,r5 -1: addi r8,r8,16 - .endr -no_segments: - - /* Restore per thread state */ - - ld r4,_SPURR(r1) - mtspr SPRN_SPURR,r4 - ld r4,_PURR(r1) - mtspr SPRN_PURR,r4 - ld r4,_DSCR(r1) - mtspr SPRN_DSCR,r4 - ld r4,_WORT(r1) - mtspr SPRN_WORT,r4 - - /* Call cur_cpu_spec->cpu_restore() */ - LOAD_REG_ADDR(r4, cur_cpu_spec) - ld r4,0(r4) - ld r12,CPU_SPEC_RESTORE(r4) -#ifdef PPC64_ELF_ABI_v1 - ld r12,0(r12) -#endif - mtctr r12 - bctrl - -/* - * On POWER9, we can come here on wakeup from a cpuidle stop state. - * Hence restore the additional SPRs to the saved value. + * The caller is responsible for saving/restoring SPRs, MSR, timebase, + * etc. * - * On POWER8, we come here only on winkle. Since winkle is used - * only in the case of CPU-Hotplug, we don't need to restore - * the additional SPRs. + * This must be called in real-mode (MSR_IDLE). */ -BEGIN_FTR_SECTION - bl power9_restore_additional_sprs -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) -hypervisor_state_restored: - - mr r12,r19 - mtlr r17 - blr /* return to pnv_powersave_wakeup */ - -fastsleep_workaround_at_exit: - li r3,1 - li r4,0 - bl opal_config_cpu_idle_state - b timebase_resync - -/* - * R3 here contains the value that will be returned to the caller - * of power7_nap. - * R12 contains SRR1 for CHECK_HMI_INTERRUPT. - */ -.global pnv_wakeup_loss -pnv_wakeup_loss: - ld r1,PACAR1(r13) -BEGIN_FTR_SECTION - CHECK_HMI_INTERRUPT -END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) - REST_NVGPRS(r1) - REST_GPR(2, r1) - -BEGIN_FTR_SECTION - /* These regs were saved in pnv_powersave_common() */ - ld r4, PNV_POWERSAVE_AMR(r1) - ld r5, PNV_POWERSAVE_IAMR(r1) - ld r6, PNV_POWERSAVE_UAMOR(r1) - mtspr SPRN_AMR, r4 - mtspr SPRN_IAMR, r5 - mtspr SPRN_UAMOR, r6 -BEGIN_FTR_SECTION_NESTED(42) - ld r7, PNV_POWERSAVE_AMOR(r1) - mtspr SPRN_AMOR, r7 -END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE, 42) - /* - * We don't need an isync here after restoring IAMR because the upcoming - * mtmsrd is execution synchronizing. - */ -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) - - ld r4,PACAKMSR(r13) - ld r5,_LINK(r1) - ld r6,_CCR(r1) - addi r1,r1,INT_FRAME_SIZE - mtlr r5 - mtcr r6 - mtmsrd r4 - blr +_GLOBAL(isa206_idle_insn_mayloss) + std r1,PACAR1(r13) + mflr r4 + mfcr r5 + /* use stack red zone rather than a new frame for saving regs */ + std r2,-8*0(r1) + std r14,-8*1(r1) + std r15,-8*2(r1) + std r16,-8*3(r1) + std r17,-8*4(r1) + std r18,-8*5(r1) + std r19,-8*6(r1) + std r20,-8*7(r1) + std r21,-8*8(r1) + std r22,-8*9(r1) + std r23,-8*10(r1) + std r24,-8*11(r1) + std r25,-8*12(r1) + std r26,-8*13(r1) + std r27,-8*14(r1) + std r28,-8*15(r1) + std r29,-8*16(r1) + std r30,-8*17(r1) + std r31,-8*18(r1) + std r4,-8*19(r1) + std r5,-8*20(r1) + cmpwi r3,PNV_THREAD_NAP + bne 1f + IDLE_STATE_ENTER_SEQ_NORET(PPC_NAP) +1: cmpwi r3,PNV_THREAD_SLEEP + bne 2f + IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP) +2: IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE) -/* - * R3 here contains the value that will be returned to the caller - * of power7_nap. - * R12 contains SRR1 for CHECK_HMI_INTERRUPT. - */ -pnv_wakeup_noloss: - lbz r0,PACA_NAPSTATELOST(r13) - cmpwi r0,0 - bne pnv_wakeup_loss - ld r1,PACAR1(r13) -BEGIN_FTR_SECTION - CHECK_HMI_INTERRUPT -END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) - ld r4,PACAKMSR(r13) - ld r5,_NIP(r1) - ld r6,_CCR(r1) - addi r1,r1,INT_FRAME_SIZE - mtlr r5 - mtcr r6 - mtmsrd r4 - blr diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 1729bf409562..70dc10aa0ccf 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -401,8 +401,8 @@ void __init check_for_initrd(void) #ifdef CONFIG_SMP -int threads_per_core, threads_per_subcore, threads_shift; -cpumask_t threads_core_mask; +int threads_per_core, threads_per_subcore, threads_shift __read_mostly; +cpumask_t threads_core_mask __read_mostly; EXPORT_SYMBOL_GPL(threads_per_core); EXPORT_SYMBOL_GPL(threads_per_subcore); EXPORT_SYMBOL_GPL(threads_shift); diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 3a5e719ef032..58d0f1ba845d 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -448,8 +448,10 @@ kvm_no_guest: rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1 mtspr SPRN_LPCR, r4 li r3, 0 - mfspr r12,SPRN_SRR1 - b pnv_wakeup_loss + /* set up cr3 and r3 for return */ + cmpdi cr3, r3, 0 + mfspr r3,SPRN_SRR1 + b idle_return_gpr_loss 53: HMT_LOW ld r5, HSTATE_KVM_VCORE(r13) diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c index e52f9b06dd9c..182112fd845a 100644 --- a/arch/powerpc/platforms/powernv/idle.c +++ b/arch/powerpc/platforms/powernv/idle.c @@ -16,6 +16,7 @@ #include <linux/device.h> #include <linux/cpu.h> +#include <asm/asm-prototypes.h> #include <asm/firmware.h> #include <asm/machdep.h> #include <asm/opal.h> @@ -48,10 +49,10 @@ static u64 pnv_default_stop_mask; static bool default_stop_found; /* - * First deep stop state. Used to figure out when to save/restore - * hypervisor context. + * First stop state levels when SPR and TB loss can occur. */ -u64 pnv_first_deep_stop_state = MAX_STOP_STATE; +static u64 pnv_first_tb_loss_level = MAX_STOP_STATE + 1; +static u64 pnv_first_spr_loss_level = MAX_STOP_STATE + 1; /* * psscr value and mask of the deepest stop idle state. @@ -62,6 +63,8 @@ static u64 pnv_deepest_stop_psscr_mask; static u64 pnv_deepest_stop_flag; static bool deepest_stop_found; +static unsigned long power7_offline_type; + static int pnv_save_sprs_for_deep_states(void) { int cpu; @@ -72,12 +75,12 @@ static int pnv_save_sprs_for_deep_states(void) * all cpus at boot. Get these reg values of current cpu and use the * same across all cpus. */ - uint64_t lpcr_val = mfspr(SPRN_LPCR); - uint64_t hid0_val = mfspr(SPRN_HID0); - uint64_t hid1_val = mfspr(SPRN_HID1); - uint64_t hid4_val = mfspr(SPRN_HID4); - uint64_t hid5_val = mfspr(SPRN_HID5); - uint64_t hmeer_val = mfspr(SPRN_HMEER); + uint64_t lpcr_val = mfspr(SPRN_LPCR); + uint64_t hid0_val = mfspr(SPRN_HID0); + uint64_t hid1_val = mfspr(SPRN_HID1); + uint64_t hid4_val = mfspr(SPRN_HID4); + uint64_t hid5_val = mfspr(SPRN_HID5); + uint64_t hmeer_val = mfspr(SPRN_HMEER); uint64_t msr_val = MSR_IDLE; uint64_t psscr_val = pnv_deepest_stop_psscr_val; @@ -137,89 +140,6 @@ static int pnv_save_sprs_for_deep_states(void) return 0; } -static void pnv_alloc_idle_core_states(void) -{ - int i, j; - int nr_cores = cpu_nr_cores(); - u32 *core_idle_state; - - /* - * core_idle_state - The lower 8 bits track the idle state of - * each thread of the core. - * - * The most significant bit is the lock bit. - * - * Initially all the bits corresponding to threads_per_core - * are set. They are cleared when the thread enters deep idle - * state like sleep and winkle/stop. - * - * Initially the lock bit is cleared. The lock bit has 2 - * purposes: - * a. While the first thread in the core waking up from - * idle is restoring core state, it prevents other - * threads in the core from switching to process - * context. - * b. While the last thread in the core is saving the - * core state, it prevents a different thread from - * waking up. - */ - for (i = 0; i < nr_cores; i++) { - int first_cpu = i * threads_per_core; - int node = cpu_to_node(first_cpu); - size_t paca_ptr_array_size; - - core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, node); - *core_idle_state = (1 << threads_per_core) - 1; - paca_ptr_array_size = (threads_per_core * - sizeof(struct paca_struct *)); - - for (j = 0; j < threads_per_core; j++) { - int cpu = first_cpu + j; - - paca_ptrs[cpu]->core_idle_state_ptr = core_idle_state; - paca_ptrs[cpu]->thread_idle_state = PNV_THREAD_RUNNING; - paca_ptrs[cpu]->thread_mask = 1 << j; - } - } - - update_subcore_sibling_mask(); - - if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT) { - int rc = pnv_save_sprs_for_deep_states(); - - if (likely(!rc)) - return; - - /* - * The stop-api is unable to restore hypervisor - * resources on wakeup from platform idle states which - * lose full context. So disable such states. - */ - supported_cpuidle_states &= ~OPAL_PM_LOSE_FULL_CONTEXT; - pr_warn("cpuidle-powernv: Disabling idle states that lose full context\n"); - pr_warn("cpuidle-powernv: Idle power-savings, CPU-Hotplug affected\n"); - - if (cpu_has_feature(CPU_FTR_ARCH_300) && - (pnv_deepest_stop_flag & OPAL_PM_LOSE_FULL_CONTEXT)) { - /* - * Use the default stop state for CPU-Hotplug - * if available. - */ - if (default_stop_found) { - pnv_deepest_stop_psscr_val = - pnv_default_stop_val; - pnv_deepest_stop_psscr_mask = - pnv_default_stop_mask; - pr_warn("cpuidle-powernv: Offlined CPUs will stop with psscr = 0x%016llx\n", - pnv_deepest_stop_psscr_val); - } else { /* Fallback to snooze loop for CPU-Hotplug */ - deepest_stop_found = false; - pr_warn("cpuidle-powernv: Offlined CPUs will busy wait\n"); - } - } - } -} - u32 pnv_get_supported_cpuidle_states(void) { return supported_cpuidle_states; @@ -238,6 +158,9 @@ static void pnv_fastsleep_workaround_apply(void *info) *err = 1; } +static bool power7_fastsleep_workaround_entry = true; +static bool power7_fastsleep_workaround_exit = true; + /* * Used to store fastsleep workaround state * 0 - Workaround applied/undone at fastsleep entry/exit path (Default) @@ -269,21 +192,15 @@ static ssize_t store_fastsleep_workaround_applyonce(struct device *dev, * fastsleep_workaround_applyonce = 1 implies * fastsleep workaround needs to be left in 'applied' state on all * the cores. Do this by- - * 1. Patching out the call to 'undo' workaround in fastsleep exit path - * 2. Sending ipi to all the cores which have at least one online thread - * 3. Patching out the call to 'apply' workaround in fastsleep entry - * path + * 1. Disable the 'undo' workaround in fastsleep exit path + * 2. Sendi IPIs to all the cores which have at least one online thread + * 3. Disable the 'apply' workaround in fastsleep entry path + * * There is no need to send ipi to cores which have all threads * offlined, as last thread of the core entering fastsleep or deeper * state would have applied workaround. */ - err = patch_instruction( - (unsigned int *)pnv_fastsleep_workaround_at_exit, - PPC_INST_NOP); - if (err) { - pr_err("fastsleep_workaround_applyonce change failed while patching pnv_fastsleep_workaround_at_exit"); - goto fail; - } + power7_fastsleep_workaround_exit = false; get_online_cpus(); primary_thread_mask = cpu_online_cores_map(); @@ -296,13 +213,7 @@ static ssize_t store_fastsleep_workaround_applyonce(struct device *dev, goto fail; } - err = patch_instruction( - (unsigned int *)pnv_fastsleep_workaround_at_entry, - PPC_INST_NOP); - if (err) { - pr_err("fastsleep_workaround_applyonce change failed while patching pnv_fastsleep_workaround_at_entry"); - goto fail; - } + power7_fastsleep_workaround_entry = false; fastsleep_workaround_applyonce = 1; @@ -315,27 +226,336 @@ static DEVICE_ATTR(fastsleep_workaround_applyonce, 0600, show_fastsleep_workaround_applyonce, store_fastsleep_workaround_applyonce); -static unsigned long __power7_idle_type(unsigned long type) +static inline void atomic_start_thread_idle(void) { + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + int thread_nr = cpu_thread_in_core(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + + clear_bit(thread_nr, state); +} + +static inline void atomic_stop_thread_idle(void) +{ + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + int thread_nr = cpu_thread_in_core(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + + set_bit(thread_nr, state); +} + +static inline void atomic_lock_thread_idle(void) +{ + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + + while (unlikely(test_and_set_bit_lock(NR_PNV_CORE_IDLE_LOCK_BIT, state))) + barrier(); +} + +static inline void atomic_unlock_and_stop_thread_idle(void) +{ + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + unsigned long thread = 1UL << cpu_thread_in_core(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + u64 s = READ_ONCE(*state); + u64 new, tmp; + + BUG_ON(!(s & PNV_CORE_IDLE_LOCK_BIT)); + BUG_ON(s & thread); + +again: + new = (s | thread) & ~PNV_CORE_IDLE_LOCK_BIT; + tmp = cmpxchg(state, s, new); + if (unlikely(tmp != s)) { + s = tmp; + goto again; + } +} + +static inline void atomic_unlock_thread_idle(void) +{ + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + + BUG_ON(!test_bit(NR_PNV_CORE_IDLE_LOCK_BIT, state)); + clear_bit_unlock(NR_PNV_CORE_IDLE_LOCK_BIT, state); +} + +/* P7 and P8 */ +struct p7_sprs { + /* per core */ + u64 tscr; + u64 worc; + + /* per subcore */ + u64 sdr1; + u64 rpr; + + /* per thread */ + u64 lpcr; + u64 hfscr; + u64 fscr; + u64 purr; + u64 spurr; + u64 dscr; + u64 wort; + + /* per thread SPRs that get lost in shallow states */ + u64 amr; + u64 iamr; + u64 amor; + u64 uamor; +}; + +static unsigned long power7_idle_insn(unsigned long type) +{ + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + unsigned long thread = 1UL << cpu_thread_in_core(cpu); + unsigned long core_thread_mask = (1UL << threads_per_core) - 1; unsigned long srr1; + bool full_winkle; + struct p7_sprs sprs = {}; /* avoid false use-uninitialised */ + bool sprs_saved = false; + int rc; - if (!prep_irq_for_idle_irqsoff()) - return 0; + if (unlikely(type != PNV_THREAD_NAP)) { + atomic_lock_thread_idle(); + + BUG_ON(!(*state & thread)); + *state &= ~thread; + + if (power7_fastsleep_workaround_entry) { + if ((*state & core_thread_mask) == 0) { + rc = opal_config_cpu_idle_state( + OPAL_CONFIG_IDLE_FASTSLEEP, + OPAL_CONFIG_IDLE_APPLY); + BUG_ON(rc); + } + } + + if (type == PNV_THREAD_WINKLE) { + sprs.tscr = mfspr(SPRN_TSCR); + sprs.worc = mfspr(SPRN_WORC); + + sprs.sdr1 = mfspr(SPRN_SDR1); + sprs.rpr = mfspr(SPRN_RPR); + + sprs.lpcr = mfspr(SPRN_LPCR); + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + sprs.hfscr = mfspr(SPRN_HFSCR); + sprs.fscr = mfspr(SPRN_FSCR); + } + sprs.purr = mfspr(SPRN_PURR); + sprs.spurr = mfspr(SPRN_SPURR); + sprs.dscr = mfspr(SPRN_DSCR); + sprs.wort = mfspr(SPRN_WORT); + + sprs_saved = true; + + /* + * Increment winkle counter and set all winkle bits if + * all threads are winkling. This allows wakeup side to + * distinguish between fast sleep and winkle state + * loss. Fast sleep still has to resync the timebase so + * this may not be a really big win. + */ + *state += 1 << PNV_CORE_IDLE_WINKLE_COUNT_SHIFT; + if ((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) + >> PNV_CORE_IDLE_WINKLE_COUNT_SHIFT + == threads_per_core) + *state |= PNV_CORE_IDLE_THREAD_WINKLE_BITS; + WARN_ON((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) == 0); + } + + atomic_unlock_thread_idle(); + } + + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + sprs.amr = mfspr(SPRN_AMR); + sprs.iamr = mfspr(SPRN_IAMR); + sprs.amor = mfspr(SPRN_AMOR); + sprs.uamor = mfspr(SPRN_UAMOR); + } + + local_paca->thread_idle_state = type; + srr1 = isa206_idle_insn_mayloss(type); /* go idle */ + local_paca->thread_idle_state = PNV_THREAD_RUNNING; + + WARN_ON_ONCE(!srr1); + WARN_ON_ONCE(mfmsr() & (MSR_IR|MSR_DR)); + + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + if ((srr1 & SRR1_WAKESTATE) != SRR1_WS_NOLOSS) { + /* + * We don't need an isync after the mtsprs here because + * the upcoming mtmsrd is execution synchronizing. + */ + mtspr(SPRN_AMR, sprs.amr); + mtspr(SPRN_IAMR, sprs.iamr); + mtspr(SPRN_AMOR, sprs.amor); + mtspr(SPRN_UAMOR, sprs.uamor); + } + } + + if (unlikely((srr1 & SRR1_WAKEMASK_P8) == SRR1_WAKEHMI)) + hmi_exception_realmode(NULL); + + if (likely((srr1 & SRR1_WAKESTATE) != SRR1_WS_HVLOSS)) { + if (unlikely(type != PNV_THREAD_NAP)) { + atomic_lock_thread_idle(); + if (type == PNV_THREAD_WINKLE) { + WARN_ON((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) == 0); + *state -= 1 << PNV_CORE_IDLE_WINKLE_COUNT_SHIFT; + *state &= ~(thread << PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT); + } + atomic_unlock_and_stop_thread_idle(); + } + return srr1; + } + + /* HV state loss */ + BUG_ON(type == PNV_THREAD_NAP); + + atomic_lock_thread_idle(); + + full_winkle = false; + if (type == PNV_THREAD_WINKLE) { + WARN_ON((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) == 0); + *state -= 1 << PNV_CORE_IDLE_WINKLE_COUNT_SHIFT; + if (*state & (thread << PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT)) { + *state &= ~(thread << PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT); + full_winkle = true; + BUG_ON(!sprs_saved); + } + } + + WARN_ON(*state & thread); + + if ((*state & core_thread_mask) != 0) + goto core_woken; + + /* Per-core SPRs */ + if (full_winkle) { + mtspr(SPRN_TSCR, sprs.tscr); + mtspr(SPRN_WORC, sprs.worc); + } + + if (power7_fastsleep_workaround_exit) { + rc = opal_config_cpu_idle_state(OPAL_CONFIG_IDLE_FASTSLEEP, + OPAL_CONFIG_IDLE_UNDO); + BUG_ON(rc); + } + + /* TB */ + if (opal_resync_timebase() != OPAL_SUCCESS) + BUG(); + +core_woken: + if (!full_winkle) + goto subcore_woken; + + if ((*state & local_paca->subcore_sibling_mask) != 0) + goto subcore_woken; + + /* Per-subcore SPRs */ + mtspr(SPRN_SDR1, sprs.sdr1); + mtspr(SPRN_RPR, sprs.rpr); + +subcore_woken: + /* + * isync after restoring shared SPRs and before unlocking. Unlock + * only contains hwsync which does not necessarily do the right + * thing for SPRs. + */ + isync(); + atomic_unlock_and_stop_thread_idle(); + + /* Fast sleep does not lose SPRs */ + if (!full_winkle) + return srr1; + + /* Per-thread SPRs */ + mtspr(SPRN_LPCR, sprs.lpcr); + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + mtspr(SPRN_HFSCR, sprs.hfscr); + mtspr(SPRN_FSCR, sprs.fscr); + } + mtspr(SPRN_PURR, sprs.purr); + mtspr(SPRN_SPURR, sprs.spurr); + mtspr(SPRN_DSCR, sprs.dscr); + mtspr(SPRN_WORT, sprs.wort); + + mtspr(SPRN_SPRG3, local_paca->sprg_vdso); + + /* + * The SLB has to be restored here, but it sometimes still + * contains entries, so the __ variant must be used to prevent + * multi hits. + */ + __slb_restore_bolted_realmode(); + + return srr1; +} + +#ifdef CONFIG_HOTPLUG_CPU +static unsigned long power7_offline(void) +{ + unsigned long srr1; + + mtmsr(MSR_IDLE); + +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + /* Tell KVM we're entering idle. */ + /******************************************************/ + /* N O T E W E L L ! ! ! N O T E W E L L */ + /* The following store to HSTATE_HWTHREAD_STATE(r13) */ + /* MUST occur in real mode, i.e. with the MMU off, */ + /* and the MMU must stay off until we clear this flag */ + /* and test HSTATE_HWTHREAD_REQ(r13) in */ + /* pnv_powersave_wakeup in this file. */ + /* The reason is that another thread can switch the */ + /* MMU to a guest context whenever this flag is set */ + /* to KVM_HWTHREAD_IN_IDLE, and if the MMU was on, */ + /* that would potentially cause this thread to start */ + /* executing instructions from guest memory in */ + /* hypervisor mode, leading to a host crash or data */ + /* corruption, or worse. */ + /******************************************************/ + local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_IDLE; +#endif __ppc64_runlatch_off(); - srr1 = power7_idle_insn(type); + srr1 = power7_idle_insn(power7_offline_type); __ppc64_runlatch_on(); - fini_irq_for_idle_irqsoff(); + mtmsr(MSR_KERNEL); return srr1; } +#endif void power7_idle_type(unsigned long type) { unsigned long srr1; - srr1 = __power7_idle_type(type); + if (!prep_irq_for_idle_irqsoff()) + return; + + mtmsr(MSR_IDLE); + __ppc64_runlatch_off(); + srr1 = power7_idle_insn(type); + __ppc64_runlatch_on(); + mtmsr(MSR_KERNEL); + + fini_irq_for_idle_irqsoff(); irq_set_pending_from_srr1(srr1); } @@ -347,33 +567,287 @@ void power7_idle(void) power7_idle_type(PNV_THREAD_NAP); } -static unsigned long __power9_idle_type(unsigned long stop_psscr_val, - unsigned long stop_psscr_mask) +struct p9_sprs { + /* per core */ + u64 ptcr; + u64 rpr; + u64 tscr; + u64 ldbar; + + /* per thread */ + u64 lpcr; + u64 hfscr; + u64 fscr; + u64 pid; + u64 purr; + u64 spurr; + u64 dscr; + u64 wort; + + u64 mmcra; + u32 mmcr0; + u32 mmcr1; + u64 mmcr2; + + /* per thread SPRs that get lost in shallow states */ + u64 amr; + u64 iamr; + u64 amor; + u64 uamor; +}; + +static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on) { - unsigned long psscr; + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + unsigned long core_thread_mask = (1UL << threads_per_core) - 1; unsigned long srr1; + unsigned long pls; + unsigned long mmcr0 = 0; + struct p9_sprs sprs = {}; /* avoid false used-uninitialised */ + bool sprs_saved = false; - if (!prep_irq_for_idle_irqsoff()) - return 0; + if (!(psscr & (PSSCR_EC|PSSCR_ESL))) { + /* EC=ESL=0 case */ + + BUG_ON(!mmu_on); + + /* + * Wake synchronously. SRESET via xscom may still cause + * a 0x100 powersave wakeup with SRR1 reason! + */ + srr1 = isa300_idle_stop_noloss(psscr); /* go idle */ + if (likely(!srr1)) + return 0; + + /* + * Registers not saved, can't recover! + * This would be a hardware bug + */ + BUG_ON((srr1 & SRR1_WAKESTATE) != SRR1_WS_NOLOSS); + + goto out; + } + + /* EC=ESL=1 case */ +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + if (cpu_has_feature(CPU_FTR_P9_TM_XER_SO_BUG)) { + local_paca->requested_psscr = psscr; + /* order setting requested_psscr vs testing dont_stop */ + smp_mb(); + if (atomic_read(&local_paca->dont_stop)) { + local_paca->requested_psscr = 0; + return 0; + } + } +#endif + + if (!cpu_has_feature(CPU_FTR_POWER9_DD2_1)) { + /* + * POWER9 DD2 can incorrectly set PMAO when waking up + * after a state-loss idle. Saving and restoring MMCR0 + * over idle is a workaround. + */ + mmcr0 = mfspr(SPRN_MMCR0); + } + if ((psscr & PSSCR_RL_MASK) >= pnv_first_spr_loss_level) { + sprs.lpcr = mfspr(SPRN_LPCR); + sprs.hfscr = mfspr(SPRN_HFSCR); + sprs.fscr = mfspr(SPRN_FSCR); + sprs.pid = mfspr(SPRN_PID); + sprs.purr = mfspr(SPRN_PURR); + sprs.spurr = mfspr(SPRN_SPURR); + sprs.dscr = mfspr(SPRN_DSCR); + sprs.wort = mfspr(SPRN_WORT); + + sprs.mmcra = mfspr(SPRN_MMCRA); + sprs.mmcr0 = mfspr(SPRN_MMCR0); + sprs.mmcr1 = mfspr(SPRN_MMCR1); + sprs.mmcr2 = mfspr(SPRN_MMCR2); + + sprs.ptcr = mfspr(SPRN_PTCR); + sprs.rpr = mfspr(SPRN_RPR); + sprs.tscr = mfspr(SPRN_TSCR); + sprs.ldbar = mfspr(SPRN_LDBAR); + + sprs_saved = true; + + atomic_start_thread_idle(); + } + + sprs.amr = mfspr(SPRN_AMR); + sprs.iamr = mfspr(SPRN_IAMR); + sprs.amor = mfspr(SPRN_AMOR); + sprs.uamor = mfspr(SPRN_UAMOR); + + srr1 = isa300_idle_stop_mayloss(psscr); /* go idle */ + +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + local_paca->requested_psscr = 0; +#endif psscr = mfspr(SPRN_PSSCR); - psscr = (psscr & ~stop_psscr_mask) | stop_psscr_val; + WARN_ON_ONCE(!srr1); + WARN_ON_ONCE(mfmsr() & (MSR_IR|MSR_DR)); + + if ((srr1 & SRR1_WAKESTATE) != SRR1_WS_NOLOSS) { + unsigned long mmcra; + + /* + * We don't need an isync after the mtsprs here because the + * upcoming mtmsrd is execution synchronizing. + */ + mtspr(SPRN_AMR, sprs.amr); + mtspr(SPRN_IAMR, sprs.iamr); + mtspr(SPRN_AMOR, sprs.amor); + mtspr(SPRN_UAMOR, sprs.uamor); + + /* + * Workaround for POWER9 DD2.0, if we lost resources, the ERAT + * might have been corrupted and needs flushing. We also need + * to reload MMCR0 (see mmcr0 comment above). + */ + if (!cpu_has_feature(CPU_FTR_POWER9_DD2_1)) { + asm volatile(PPC_INVALIDATE_ERAT); + mtspr(SPRN_MMCR0, mmcr0); + } + + /* + * DD2.2 and earlier need to set then clear bit 60 in MMCRA + * to ensure the PMU starts running. + */ + mmcra = mfspr(SPRN_MMCRA); + mmcra |= PPC_BIT(60); + mtspr(SPRN_MMCRA, mmcra); + mmcra &= ~PPC_BIT(60); + mtspr(SPRN_MMCRA, mmcra); + } + + if (unlikely((srr1 & SRR1_WAKEMASK_P8) == SRR1_WAKEHMI)) + hmi_exception_realmode(NULL); + + /* + * On POWER9, SRR1 bits do not match exactly as expected. + * SRR1_WS_GPRLOSS (10b) can also result in SPR loss, so + * just always test PSSCR for SPR/TB state loss. + */ + pls = (psscr & PSSCR_PLS) >> PSSCR_PLS_SHIFT; + if (likely(pls < pnv_first_spr_loss_level)) { + if (sprs_saved) + atomic_stop_thread_idle(); + goto out; + } + + /* HV state loss */ + BUG_ON(!sprs_saved); + + atomic_lock_thread_idle(); + + if ((*state & core_thread_mask) != 0) + goto core_woken; + + /* Per-core SPRs */ + mtspr(SPRN_PTCR, sprs.ptcr); + mtspr(SPRN_RPR, sprs.rpr); + mtspr(SPRN_TSCR, sprs.tscr); + mtspr(SPRN_LDBAR, sprs.ldbar); + + if (pls >= pnv_first_tb_loss_level) { + /* TB loss */ + if (opal_resync_timebase() != OPAL_SUCCESS) + BUG(); + } + + /* + * isync after restoring shared SPRs and before unlocking. Unlock + * only contains hwsync which does not necessarily do the right + * thing for SPRs. + */ + isync(); + +core_woken: + atomic_unlock_and_stop_thread_idle(); + + /* Per-thread SPRs */ + mtspr(SPRN_LPCR, sprs.lpcr); + mtspr(SPRN_HFSCR, sprs.hfscr); + mtspr(SPRN_FSCR, sprs.fscr); + mtspr(SPRN_PID, sprs.pid); + mtspr(SPRN_PURR, sprs.purr); + mtspr(SPRN_SPURR, sprs.spurr); + mtspr(SPRN_DSCR, sprs.dscr); + mtspr(SPRN_WORT, sprs.wort); + + mtspr(SPRN_MMCRA, sprs.mmcra); + mtspr(SPRN_MMCR0, sprs.mmcr0); + mtspr(SPRN_MMCR1, sprs.mmcr1); + mtspr(SPRN_MMCR2, sprs.mmcr2); + + mtspr(SPRN_SPRG3, local_paca->sprg_vdso); + + if (!radix_enabled()) + __slb_restore_bolted_realmode(); + +out: + if (mmu_on) + mtmsr(MSR_KERNEL); + + return srr1; +} + +#ifdef CONFIG_HOTPLUG_CPU +static unsigned long power9_offline_stop(unsigned long psscr) +{ + unsigned long srr1; + +#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE __ppc64_runlatch_off(); - srr1 = power9_idle_stop(psscr); + srr1 = power9_idle_stop(psscr, true); __ppc64_runlatch_on(); +#else + /* + * Tell KVM we're entering idle. + * This does not have to be done in real mode because the P9 MMU + * is independent per-thread. Some steppings share radix/hash mode + * between threads, but in that case KVM has a barrier sync in real + * mode before and after switching between radix and hash. + * + * kvm_start_guest must still be called in real mode though, hence + * the false argument. + */ + local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_IDLE; - fini_irq_for_idle_irqsoff(); + __ppc64_runlatch_off(); + srr1 = power9_idle_stop(psscr, false); + __ppc64_runlatch_on(); + + mtmsr(MSR_KERNEL); +#endif return srr1; } +#endif void power9_idle_type(unsigned long stop_psscr_val, unsigned long stop_psscr_mask) { + unsigned long psscr; unsigned long srr1; - srr1 = __power9_idle_type(stop_psscr_val, stop_psscr_mask); + if (!prep_irq_for_idle_irqsoff()) + return; + + psscr = mfspr(SPRN_PSSCR); + psscr = (psscr & ~stop_psscr_mask) | stop_psscr_val; + + __ppc64_runlatch_off(); + srr1 = power9_idle_stop(psscr, true); + __ppc64_runlatch_on(); + + fini_irq_for_idle_irqsoff(); + irq_set_pending_from_srr1(srr1); } @@ -409,7 +883,7 @@ void pnv_power9_force_smt4_catch(void) atomic_inc(&paca_ptrs[cpu0+thr]->dont_stop); } /* order setting dont_stop vs testing requested_psscr */ - mb(); + smp_mb(); for (thr = 0; thr < threads_per_core; ++thr) { if (!paca_ptrs[cpu0+thr]->requested_psscr) ++awake_threads; @@ -481,7 +955,6 @@ void pnv_program_cpu_hotplug_lpcr(unsigned int cpu, u64 lpcr_val) unsigned long pnv_cpu_offline(unsigned int cpu) { unsigned long srr1; - u32 idle_states = pnv_get_supported_cpuidle_states(); __ppc64_runlatch_off(); @@ -492,15 +965,8 @@ unsigned long pnv_cpu_offline(unsigned int cpu) psscr = (psscr & ~pnv_deepest_stop_psscr_mask) | pnv_deepest_stop_psscr_val; srr1 = power9_offline_stop(psscr); - - } else if ((idle_states & OPAL_PM_WINKLE_ENABLED) && - (idle_states & OPAL_PM_LOSE_FULL_CONTEXT)) { - srr1 = power7_idle_insn(PNV_THREAD_WINKLE); - } else if ((idle_states & OPAL_PM_SLEEP_ENABLED) || - (idle_states & OPAL_PM_SLEEP_ENABLED_ER1)) { - srr1 = power7_idle_insn(PNV_THREAD_SLEEP); - } else if (idle_states & OPAL_PM_NAP_ENABLED) { - srr1 = power7_idle_insn(PNV_THREAD_NAP); + } else if (cpu_has_feature(CPU_FTR_ARCH_206) && power7_offline_type) { + srr1 = power7_offline(); } else { /* This is the fallback method. We emulate snooze */ while (!generic_check_cpu_restart(cpu)) { @@ -596,33 +1062,44 @@ int validate_psscr_val_mask(u64 *psscr_val, u64 *psscr_mask, u32 flags) * @dt_idle_states: Number of idle state entries * Returns 0 on success */ -static int __init pnv_power9_idle_init(void) +static void __init pnv_power9_idle_init(void) { u64 max_residency_ns = 0; int i; /* - * Set pnv_first_deep_stop_state, pnv_deepest_stop_psscr_{val,mask}, - * and the pnv_default_stop_{val,mask}. - * - * pnv_first_deep_stop_state should be set to the first stop - * level to cause hypervisor state loss. - * * pnv_deepest_stop_{val,mask} should be set to values corresponding to * the deepest stop state. * * pnv_default_stop_{val,mask} should be set to values corresponding to - * the shallowest (OPAL_PM_STOP_INST_FAST) loss-less stop state. + * the deepest loss-less (OPAL_PM_STOP_INST_FAST) stop state. */ - pnv_first_deep_stop_state = MAX_STOP_STATE; + pnv_first_tb_loss_level = MAX_STOP_STATE + 1; + pnv_first_spr_loss_level = MAX_STOP_STATE + 1; for (i = 0; i < nr_pnv_idle_states; i++) { int err; struct pnv_idle_states_t *state = &pnv_idle_states[i]; u64 psscr_rl = state->psscr_val & PSSCR_RL_MASK; + if ((state->flags & OPAL_PM_TIMEBASE_STOP) && + (pnv_first_tb_loss_level > psscr_rl)) + pnv_first_tb_loss_level = psscr_rl; + if ((state->flags & OPAL_PM_LOSE_FULL_CONTEXT) && - pnv_first_deep_stop_state > psscr_rl) - pnv_first_deep_stop_state = psscr_rl; + (pnv_first_spr_loss_level > psscr_rl)) + pnv_first_spr_loss_level = psscr_rl; + + /* + * The idle code does not deal with TB loss occurring + * in a shallower state than SPR loss, so force it to + * behave like SPRs are lost if TB is lost. POWER9 would + * never encouter this, but a POWER8 core would if it + * implemented the stop instruction. So this is for forward + * compatibility. + */ + if ((state->flags & OPAL_PM_TIMEBASE_STOP) && + (pnv_first_spr_loss_level > psscr_rl)) + pnv_first_spr_loss_level = psscr_rl; err = validate_psscr_val_mask(&state->psscr_val, &state->psscr_mask, @@ -647,6 +1124,7 @@ static int __init pnv_power9_idle_init(void) pnv_default_stop_val = state->psscr_val; pnv_default_stop_mask = state->psscr_mask; default_stop_found = true; + WARN_ON(state->flags & OPAL_PM_LOSE_FULL_CONTEXT); } } @@ -666,10 +1144,40 @@ static int __init pnv_power9_idle_init(void) pnv_deepest_stop_psscr_mask); } - pr_info("cpuidle-powernv: Requested Level (RL) value of first deep stop = 0x%llx\n", - pnv_first_deep_stop_state); + pr_info("cpuidle-powernv: First stop level that may lose SPRs = 0x%lld\n", + pnv_first_spr_loss_level); - return 0; + pr_info("cpuidle-powernv: First stop level that may lose timebase = 0x%lld\n", + pnv_first_tb_loss_level); +} + +static void __init pnv_disable_deep_states(void) +{ + /* + * The stop-api is unable to restore hypervisor + * resources on wakeup from platform idle states which + * lose full context. So disable such states. + */ + supported_cpuidle_states &= ~OPAL_PM_LOSE_FULL_CONTEXT; + pr_warn("cpuidle-powernv: Disabling idle states that lose full context\n"); + pr_warn("cpuidle-powernv: Idle power-savings, CPU-Hotplug affected\n"); + + if (cpu_has_feature(CPU_FTR_ARCH_300) && + (pnv_deepest_stop_flag & OPAL_PM_LOSE_FULL_CONTEXT)) { + /* + * Use the default stop state for CPU-Hotplug + * if available. + */ + if (default_stop_found) { + pnv_deepest_stop_psscr_val = pnv_default_stop_val; + pnv_deepest_stop_psscr_mask = pnv_default_stop_mask; + pr_warn("cpuidle-powernv: Offlined CPUs will stop with psscr = 0x%016llx\n", + pnv_deepest_stop_psscr_val); + } else { /* Fallback to snooze loop for CPU-Hotplug */ + deepest_stop_found = false; + pr_warn("cpuidle-powernv: Offlined CPUs will busy wait\n"); + } + } } /* @@ -684,10 +1192,8 @@ static void __init pnv_probe_idle_states(void) return; } - if (cpu_has_feature(CPU_FTR_ARCH_300)) { - if (pnv_power9_idle_init()) - return; - } + if (cpu_has_feature(CPU_FTR_ARCH_300)) + pnv_power9_idle_init(); for (i = 0; i < nr_pnv_idle_states; i++) supported_cpuidle_states |= pnv_idle_states[i].flags; @@ -807,11 +1313,33 @@ static int pnv_parse_cpuidle_dt(void) static int __init pnv_init_idle_states(void) { + int cpu; int rc = 0; - supported_cpuidle_states = 0; + + /* Set up PACA fields */ + for_each_present_cpu(cpu) { + struct paca_struct *p = paca_ptrs[cpu]; + + p->idle_state = 0; + if (cpu == cpu_first_thread_sibling(cpu)) + p->idle_state = (1 << threads_per_core) - 1; + + if (!cpu_has_feature(CPU_FTR_ARCH_300)) { + /* P7/P8 nap */ + p->thread_idle_state = PNV_THREAD_RUNNING; + } else { + /* P9 stop */ +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + p->requested_psscr = 0; + atomic_set(&p->dont_stop, 0); +#endif + } + } /* In case we error out nr_pnv_idle_states will be zero */ nr_pnv_idle_states = 0; + supported_cpuidle_states = 0; + if (cpuidle_disable != IDLE_NO_OVERRIDE) goto out; rc = pnv_parse_cpuidle_dt(); @@ -819,27 +1347,40 @@ static int __init pnv_init_idle_states(void) return rc; pnv_probe_idle_states(); - if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) { - patch_instruction( - (unsigned int *)pnv_fastsleep_workaround_at_entry, - PPC_INST_NOP); - patch_instruction( - (unsigned int *)pnv_fastsleep_workaround_at_exit, - PPC_INST_NOP); - } else { - /* - * OPAL_PM_SLEEP_ENABLED_ER1 is set. It indicates that - * workaround is needed to use fastsleep. Provide sysfs - * control to choose how this workaround has to be applied. - */ - device_create_file(cpu_subsys.dev_root, + if (!cpu_has_feature(CPU_FTR_ARCH_300)) { + if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) { + power7_fastsleep_workaround_entry = false; + power7_fastsleep_workaround_exit = false; + } else { + /* + * OPAL_PM_SLEEP_ENABLED_ER1 is set. It indicates that + * workaround is needed to use fastsleep. Provide sysfs + * control to choose how this workaround has to be + * applied. + */ + device_create_file(cpu_subsys.dev_root, &dev_attr_fastsleep_workaround_applyonce); - } + } + + update_subcore_sibling_mask(); + + if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED) { + ppc_md.power_save = power7_idle; + power7_offline_type = PNV_THREAD_NAP; + } - pnv_alloc_idle_core_states(); + if ((supported_cpuidle_states & OPAL_PM_WINKLE_ENABLED) && + (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT)) + power7_offline_type = PNV_THREAD_WINKLE; + else if ((supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED) || + (supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) + power7_offline_type = PNV_THREAD_SLEEP; + } - if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED) - ppc_md.power_save = power7_idle; + if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT) { + if (pnv_save_sprs_for_deep_states()) + pnv_disable_deep_states(); + } out: return 0; diff --git a/arch/powerpc/platforms/powernv/subcore.c b/arch/powerpc/platforms/powernv/subcore.c index 45563004feda..1d7a9fd30dd1 100644 --- a/arch/powerpc/platforms/powernv/subcore.c +++ b/arch/powerpc/platforms/powernv/subcore.c @@ -183,7 +183,7 @@ static void unsplit_core(void) cpu = smp_processor_id(); if (cpu_thread_in_core(cpu) != 0) { while (mfspr(SPRN_HID0) & mask) - power7_idle_insn(PNV_THREAD_NAP); + power7_idle_type(PNV_THREAD_NAP); per_cpu(split_state, cpu).step = SYNC_STEP_UNSPLIT; return; diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index a0f44f992360..77197110e900 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -2431,7 +2431,9 @@ static void dump_one_paca(int cpu) DUMP(p, irq_happened, "%#-*x"); DUMP(p, io_sync, "%#-*x"); DUMP(p, irq_work_pending, "%#-*x"); +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE DUMP(p, nap_state_lost, "%#-*x"); +#endif DUMP(p, sprg_vdso, "%#-*llx"); #ifdef CONFIG_PPC_TRANSACTIONAL_MEM @@ -2439,19 +2441,16 @@ static void dump_one_paca(int cpu) #endif #ifdef CONFIG_PPC_POWERNV - DUMP(p, core_idle_state_ptr, "%-*px"); - DUMP(p, thread_idle_state, "%#-*x"); - DUMP(p, thread_mask, "%#-*x"); - DUMP(p, subcore_sibling_mask, "%#-*x"); - DUMP(p, requested_psscr, "%#-*llx"); - DUMP(p, stop_sprs.pid, "%#-*llx"); - DUMP(p, stop_sprs.ldbar, "%#-*llx"); - DUMP(p, stop_sprs.fscr, "%#-*llx"); - DUMP(p, stop_sprs.hfscr, "%#-*llx"); - DUMP(p, stop_sprs.mmcr1, "%#-*llx"); - DUMP(p, stop_sprs.mmcr2, "%#-*llx"); - DUMP(p, stop_sprs.mmcra, "%#-*llx"); - DUMP(p, dont_stop.counter, "%#-*x"); + DUMP(p, idle_state, "%#-*lx"); + if (!early_cpu_has_feature(CPU_FTR_ARCH_300)) { + DUMP(p, thread_idle_state, "%#-*x"); + DUMP(p, subcore_sibling_mask, "%#-*x"); + } else { +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + DUMP(p, requested_psscr, "%#-*llx"); + DUMP(p, dont_stop.counter, "%#-*x"); +#endif + } #endif DUMP(p, accounting.utime, "%#-*lx"); -- 2.20.1 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v10 1/2] powerpc/64s: reimplement book3s idle code in C @ 2019-04-28 11:45 ` Nicholas Piggin 0 siblings, 0 replies; 10+ messages in thread From: Nicholas Piggin @ 2019-04-28 11:45 UTC (permalink / raw) To: linuxppc-dev; +Cc: Gautham R . Shenoy, kvm-ppc, Nicholas Piggin Reimplement Book3S idle code in C, moving POWER7/8/9 implementation speific HV idle code to the powernv platform code. Book3S assembly stubs are kept in common code and used only to save the stack frame and non-volatile GPRs before executing architected idle instructions, and restoring the stack and reloading GPRs then returning to C after waking from idle. The complex logic dealing with threads and subcores, locking, SPRs, HMIs, timebase resync, etc., is all done in C which makes it more maintainable. This is not a strict 1:1 translation to C code, there are some significant differences: - Idle wakeup no longer uses the ->cpu_restore call to reinit SPRs, but saves and restores them itself. - The optimisation where EC=ESL=0 idle modes did not have to save GPRs or change MSR is restored, because it's now simple to do. ESL=1 sleeps that do not lose GPRs can use this optimization too. - KVM secondary entry and cede is now more of a call/return style rather than branchy. nap_state_lost is not required because KVM always returns via NVGPR restoring path. - KVM secondary wakeup from offline sequence is moved entirely into the offline wakeup, which avoids a hwsync in the normal idle wakeup path. Performance measured with context switch ping-pong on different threads or cores, is possibly improved a small amount, 1-3% depending on stop state and core vs thread test for shallow states. Deep states it's in the noise compared with other latencies. Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Notes: - I've broken the KVM code into the second patch just for review. The first patch makes KVM kind-of work with its existing design in the new idle code. The problem is the kvm_start_guest case branches out from the low level asm, which now no longer fixes up SPRs. Guests will somewhat run with deep idle states disabled for offline. Rather than a significant rework of the code to make old-KVM work with new-idle code that would need testing and review and then gets undone by the next patch, I have just broken it up like this for hopefully easier review of the KVM parts. Patches can be squashed together before upstream merge. - P9 restores some of the PMU SPRs, but not others, and P8 only zeroes them. There are improvmets to be made to SPR save restore policies and documentation, but this first pass tries to keep things as they were. More work likely needs to be done here. Left to do: - Test actual POWER7 hardware. Will check about that tomorrow. Since v9: - Fix ELFv1 build error. - Port to powerpc next. - Test POWER8 and POWER9 online/offline - Test POWER8 and POWER9 KVM guests with threads, combinations of MMU modes in guest and host, indep threads mode, etc. --- arch/powerpc/include/asm/cpuidle.h | 19 +- arch/powerpc/include/asm/paca.h | 41 +- arch/powerpc/include/asm/processor.h | 9 +- arch/powerpc/include/asm/reg.h | 8 +- arch/powerpc/kernel/asm-offsets.c | 17 - arch/powerpc/kernel/exceptions-64s.S | 25 +- arch/powerpc/kernel/idle_book3s.S | 1097 +++------------------- arch/powerpc/kernel/setup-common.c | 4 +- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 6 +- arch/powerpc/platforms/powernv/idle.c | 887 +++++++++++++---- arch/powerpc/platforms/powernv/subcore.c | 2 +- arch/powerpc/xmon/xmon.c | 25 +- 12 files changed, 941 insertions(+), 1199 deletions(-) diff --git a/arch/powerpc/include/asm/cpuidle.h b/arch/powerpc/include/asm/cpuidle.h index 43e5f31fe64d..9844b3ded187 100644 --- a/arch/powerpc/include/asm/cpuidle.h +++ b/arch/powerpc/include/asm/cpuidle.h @@ -27,10 +27,11 @@ * the THREAD_WINKLE_BITS are set, which indicate which threads have not * yet woken from the winkle state. */ -#define PNV_CORE_IDLE_LOCK_BIT 0x10000000 +#define NR_PNV_CORE_IDLE_LOCK_BIT 28 +#define PNV_CORE_IDLE_LOCK_BIT (1ULL << NR_PNV_CORE_IDLE_LOCK_BIT) +#define PNV_CORE_IDLE_WINKLE_COUNT_SHIFT 16 #define PNV_CORE_IDLE_WINKLE_COUNT 0x00010000 -#define PNV_CORE_IDLE_WINKLE_COUNT_ALL_BIT 0x00080000 #define PNV_CORE_IDLE_WINKLE_COUNT_BITS 0x000F0000 #define PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT 8 #define PNV_CORE_IDLE_THREAD_WINKLE_BITS 0x0000FF00 @@ -68,16 +69,6 @@ #define ERR_DEEP_STATE_ESL_MISMATCH -2 #ifndef __ASSEMBLY__ -/* Additional SPRs that need to be saved/restored during stop */ -struct stop_sprs { - u64 pid; - u64 ldbar; - u64 fscr; - u64 hfscr; - u64 mmcr1; - u64 mmcr2; - u64 mmcra; -}; #define PNV_IDLE_NAME_LEN 16 struct pnv_idle_states_t { @@ -92,10 +83,6 @@ struct pnv_idle_states_t { extern struct pnv_idle_states_t *pnv_idle_states; extern int nr_pnv_idle_states; -extern u32 pnv_fastsleep_workaround_at_entry[]; -extern u32 pnv_fastsleep_workaround_at_exit[]; - -extern u64 pnv_first_deep_stop_state; unsigned long pnv_cpu_offline(unsigned int cpu); int validate_psscr_val_mask(u64 *psscr_val, u64 *psscr_mask, u32 flags); diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index e843bc5d1a0f..e55dedd7ee3e 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -173,8 +173,8 @@ struct paca_struct { u8 irq_happened; /* irq happened while soft-disabled */ u8 io_sync; /* writel() needs spin_unlock sync */ u8 irq_work_pending; /* IRQ_WORK interrupt while soft-disable */ - u8 nap_state_lost; /* NV GPR values lost in power7_idle */ #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + u8 nap_state_lost; /* NV GPR values lost in power7_idle */ u8 pmcregs_in_use; /* pseries puts this in lppaca */ #endif u64 sprg_vdso; /* Saved user-visible sprg */ @@ -183,23 +183,28 @@ struct paca_struct { #endif #ifdef CONFIG_PPC_POWERNV - /* Per-core mask tracking idle threads and a lock bit-[L][TTTTTTTT] */ - u32 *core_idle_state_ptr; - u8 thread_idle_state; /* PNV_THREAD_RUNNING/NAP/SLEEP */ - /* Mask to indicate thread id in core */ - u8 thread_mask; - /* Mask to denote subcore sibling threads */ - u8 subcore_sibling_mask; - /* Flag to request this thread not to stop */ - atomic_t dont_stop; - /* The PSSCR value that the kernel requested before going to stop */ - u64 requested_psscr; - - /* - * Save area for additional SPRs that need to be - * saved/restored during cpuidle stop. - */ - struct stop_sprs stop_sprs; + /* PowerNV idle fields */ + /* PNV_CORE_IDLE_* bits, all siblings work on thread 0 paca */ + unsigned long idle_state; + union { + /* P7/P8 specific fields */ + struct { + /* PNV_THREAD_RUNNING/NAP/SLEEP */ + u8 thread_idle_state; + /* Mask to denote subcore sibling threads */ + u8 subcore_sibling_mask; + }; + + /* P9 specific fields */ + struct { +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + /* The PSSCR value that the kernel requested before going to stop */ + u64 requested_psscr; + /* Flag to request this thread not to stop */ + atomic_t dont_stop; +#endif + }; + }; #endif #ifdef CONFIG_PPC_BOOK3S_64 diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index 540949b397d4..706ac5df546f 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -414,14 +414,17 @@ static inline unsigned long get_clean_sp(unsigned long sp, int is_32) } #endif +/* asm stubs */ +extern unsigned long isa300_idle_stop_noloss(unsigned long psscr_val); +extern unsigned long isa300_idle_stop_mayloss(unsigned long psscr_val); +extern unsigned long isa206_idle_insn_mayloss(unsigned long type); + extern unsigned long cpuidle_disable; enum idle_boot_override {IDLE_NO_OVERRIDE = 0, IDLE_POWERSAVE_OFF}; extern int powersave_nap; /* set if nap mode can be used in idle loop */ -extern unsigned long power7_idle_insn(unsigned long type); /* PNV_THREAD_NAP/etc*/ + extern void power7_idle_type(unsigned long type); -extern unsigned long power9_idle_stop(unsigned long psscr_val); -extern unsigned long power9_offline_stop(unsigned long psscr_val); extern void power9_idle_type(unsigned long stop_psscr_val, unsigned long stop_psscr_mask); diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index c5b2aff0ce8e..10caa145f98b 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -168,6 +168,7 @@ #define PSSCR_ESL 0x00200000 /* Enable State Loss */ #define PSSCR_SD 0x00400000 /* Status Disable */ #define PSSCR_PLS 0xf000000000000000 /* Power-saving Level Status */ +#define PSSCR_PLS_SHIFT 60 #define PSSCR_GUEST_VIS 0xf0000000000003ffUL /* Guest-visible PSSCR fields */ #define PSSCR_FAKE_SUSPEND 0x00000400 /* Fake-suspend bit (P9 DD2.2) */ #define PSSCR_FAKE_SUSPEND_LG 10 /* Fake-suspend bit position */ @@ -758,10 +759,9 @@ #define SRR1_WAKERESET 0x00100000 /* System reset */ #define SRR1_WAKEHDBELL 0x000c0000 /* Hypervisor doorbell on P8 */ #define SRR1_WAKESTATE 0x00030000 /* Powersave exit mask [46:47] */ -#define SRR1_WS_DEEPEST 0x00030000 /* Some resources not maintained, - * may not be recoverable */ -#define SRR1_WS_DEEPER 0x00020000 /* Some resources not maintained */ -#define SRR1_WS_DEEP 0x00010000 /* All resources maintained */ +#define SRR1_WS_HVLOSS 0x00030000 /* HV resources not maintained */ +#define SRR1_WS_GPRLOSS 0x00020000 /* GPRs not maintained */ +#define SRR1_WS_NOLOSS 0x00010000 /* All resources maintained */ #define SRR1_PROGTM 0x00200000 /* TM Bad Thing */ #define SRR1_PROGFPE 0x00100000 /* Floating Point Enabled */ #define SRR1_PROGILL 0x00080000 /* Illegal instruction */ diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 60b82198de7c..a14a77bc4243 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -773,23 +773,6 @@ int main(void) OFFSET(VCPU_TIMING_LAST_ENTER_TBL, kvm_vcpu, arch.timing_last_enter.tv32.tbl); #endif -#ifdef CONFIG_PPC_POWERNV - OFFSET(PACA_CORE_IDLE_STATE_PTR, paca_struct, core_idle_state_ptr); - OFFSET(PACA_THREAD_IDLE_STATE, paca_struct, thread_idle_state); - OFFSET(PACA_THREAD_MASK, paca_struct, thread_mask); - OFFSET(PACA_SUBCORE_SIBLING_MASK, paca_struct, subcore_sibling_mask); - OFFSET(PACA_REQ_PSSCR, paca_struct, requested_psscr); - OFFSET(PACA_DONT_STOP, paca_struct, dont_stop); -#define STOP_SPR(x, f) OFFSET(x, paca_struct, stop_sprs.f) - STOP_SPR(STOP_PID, pid); - STOP_SPR(STOP_LDBAR, ldbar); - STOP_SPR(STOP_FSCR, fscr); - STOP_SPR(STOP_HFSCR, hfscr); - STOP_SPR(STOP_MMCR1, mmcr1); - STOP_SPR(STOP_MMCR2, mmcr2); - STOP_SPR(STOP_MMCRA, mmcra); -#endif - DEFINE(PPC_DBELL_SERVER, PPC_DBELL_SERVER); DEFINE(PPC_DBELL_MSGTYPE, PPC_DBELL_MSGTYPE); diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index bedd89438827..671c256da167 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -121,7 +121,7 @@ EXC_VIRT_NONE(0x4000, 0x100) mfspr r10,SPRN_SRR1 ; \ rlwinm. r10,r10,47-31,30,31 ; \ beq- 1f ; \ - cmpwi cr3,r10,2 ; \ + cmpwi cr1,r10,2 ; \ BRANCH_TO_C000(r10, system_reset_idle_common) ; \ 1: \ KVMTEST_PR(n) ; \ @@ -145,8 +145,13 @@ TRAMP_KVM(PACA_EXNMI, 0x100) #ifdef CONFIG_PPC_P7_NAP EXC_COMMON_BEGIN(system_reset_idle_common) - mfspr r12,SPRN_SRR1 - b pnv_powersave_wakeup + mfspr r3,SPRN_SRR1 +#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE + /* this bltlr could be moved before the branch_to, and the + * branch_to could maybe go straight to idle_return */ + bltlr cr1 /* no state loss, return to idle caller */ +#endif + b idle_return_gpr_loss #endif /* @@ -429,17 +434,19 @@ EXC_COMMON_BEGIN(machine_check_idle_common) * Then decrement MCE nesting after finishing with the stack. */ ld r3,_MSR(r1) + ld r4,_LINK(r1) lhz r11,PACA_IN_MCE(r13) subi r11,r11,1 sth r11,PACA_IN_MCE(r13) - /* Turn off the RI bit because SRR1 is used by idle wakeup code. */ - /* Recoverability could be improved by reducing the use of SRR1. */ - li r11,0 - mtmsrd r11,1 - - b pnv_powersave_wakeup_mce + mtlr r4 + rlwinm r10,r3,47-31,30,31 + cmpwi cr1,r10,2 +#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE + bltlr cr1 /* no state loss, return to idle caller */ +#endif + b idle_return_gpr_loss #endif /* * Handle machine check early in real mode. We come here with diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index 4a860d3b9229..0fb2eb731a29 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -1,539 +1,98 @@ /* - * This file contains idle entry/exit functions for POWER7, - * POWER8 and POWER9 CPUs. + * Copyright 2018, IBM Corporation. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. + * + * This file contains general idle entry/exit functions to save + * and restore stack and NVGPRs which allows C code to call idle + * states that lose GPRs, and it will return transparently with + * SRR1 wakeup reason return value. + * + * The platform / CPU caller must ensure SPRs and any other non-GPR + * state is saved and restored correctly, handle KVM, interrupts, etc. */ -#include <linux/threads.h> -#include <asm/processor.h> -#include <asm/page.h> -#include <asm/cputable.h> -#include <asm/thread_info.h> #include <asm/ppc_asm.h> #include <asm/asm-offsets.h> #include <asm/ppc-opcode.h> -#include <asm/hw_irq.h> -#include <asm/kvm_book3s_asm.h> -#include <asm/opal.h> #include <asm/cpuidle.h> -#include <asm/exception-64s.h> -#include <asm/book3s/64/mmu-hash.h> -#include <asm/mmu.h> -#include <asm/asm-compat.h> -#include <asm/feature-fixups.h> - -#undef DEBUG - -/* - * Use unused space in the interrupt stack to save and restore - * registers for winkle support. - */ -#define _MMCR0 GPR0 -#define _SDR1 GPR3 -#define _PTCR GPR3 -#define _RPR GPR4 -#define _SPURR GPR5 -#define _PURR GPR6 -#define _TSCR GPR7 -#define _DSCR GPR8 -#define _AMOR GPR9 -#define _WORT GPR10 -#define _WORC GPR11 -#define _LPCR GPR12 - -#define PSSCR_EC_ESL_MASK_SHIFTED (PSSCR_EC | PSSCR_ESL) >> 16 - - .text +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE +#include <asm/kvm_book3s_asm.h> +#endif /* - * Used by threads before entering deep idle states. Saves SPRs - * in interrupt stack frame - */ -save_sprs_to_stack: - /* - * Note all register i.e per-core, per-subcore or per-thread is saved - * here since any thread in the core might wake up first - */ -BEGIN_FTR_SECTION - /* - * Note - SDR1 is dropped in Power ISA v3. Hence not restoring - * SDR1 here - */ - mfspr r3,SPRN_PTCR - std r3,_PTCR(r1) - mfspr r3,SPRN_LPCR - std r3,_LPCR(r1) -FTR_SECTION_ELSE - mfspr r3,SPRN_SDR1 - std r3,_SDR1(r1) -ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300) - mfspr r3,SPRN_RPR - std r3,_RPR(r1) - mfspr r3,SPRN_SPURR - std r3,_SPURR(r1) - mfspr r3,SPRN_PURR - std r3,_PURR(r1) - mfspr r3,SPRN_TSCR - std r3,_TSCR(r1) - mfspr r3,SPRN_DSCR - std r3,_DSCR(r1) - mfspr r3,SPRN_AMOR - std r3,_AMOR(r1) - mfspr r3,SPRN_WORT - std r3,_WORT(r1) - mfspr r3,SPRN_WORC - std r3,_WORC(r1) -/* - * On POWER9, there are idle states such as stop4, invoked via cpuidle, - * that lose hypervisor resources. In such cases, we need to save - * additional SPRs before entering those idle states so that they can - * be restored to their older values on wakeup from the idle state. + * Desired PSSCR in r3 * - * On POWER8, the only such deep idle state is winkle which is used - * only in the context of CPU-Hotplug, where these additional SPRs are - * reinitiazed to a sane value. Hence there is no need to save/restore - * these SPRs. - */ -BEGIN_FTR_SECTION - blr -END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) - -power9_save_additional_sprs: - mfspr r3, SPRN_PID - mfspr r4, SPRN_LDBAR - std r3, STOP_PID(r13) - std r4, STOP_LDBAR(r13) - - mfspr r3, SPRN_FSCR - mfspr r4, SPRN_HFSCR - std r3, STOP_FSCR(r13) - std r4, STOP_HFSCR(r13) - - mfspr r3, SPRN_MMCRA - mfspr r4, SPRN_MMCR0 - std r3, STOP_MMCRA(r13) - std r4, _MMCR0(r1) - - mfspr r3, SPRN_MMCR1 - mfspr r4, SPRN_MMCR2 - std r3, STOP_MMCR1(r13) - std r4, STOP_MMCR2(r13) - blr - -power9_restore_additional_sprs: - ld r3,_LPCR(r1) - ld r4, STOP_PID(r13) - mtspr SPRN_LPCR,r3 - mtspr SPRN_PID, r4 - - ld r3, STOP_LDBAR(r13) - ld r4, STOP_FSCR(r13) - mtspr SPRN_LDBAR, r3 - mtspr SPRN_FSCR, r4 - - ld r3, STOP_HFSCR(r13) - ld r4, STOP_MMCRA(r13) - mtspr SPRN_HFSCR, r3 - mtspr SPRN_MMCRA, r4 - - ld r3, _MMCR0(r1) - ld r4, STOP_MMCR1(r13) - mtspr SPRN_MMCR0, r3 - mtspr SPRN_MMCR1, r4 - - ld r3, STOP_MMCR2(r13) - ld r4, PACA_SPRG_VDSO(r13) - mtspr SPRN_MMCR2, r3 - mtspr SPRN_SPRG3, r4 - blr - -/* - * Used by threads when the lock bit of core_idle_state is set. - * Threads will spin in HMT_LOW until the lock bit is cleared. - * r14 - pointer to core_idle_state - * r15 - used to load contents of core_idle_state - * r9 - used as a temporary variable + * No state will be lost regardless of wakeup mechanism (interrupt or NIA). + * + * An EC=0 type wakeup will return with a value of 0. SRESET wakeup (which can + * happen with xscom SRESET and possibly MCE) may clobber volatiles except LR, + * and must blr, to return to caller with r3 set according to caller's expected + * return code (for Book3S/64 that is SRR1). */ - -core_idle_lock_held: - HMT_LOW -3: lwz r15,0(r14) - andis. r15,r15,PNV_CORE_IDLE_LOCK_BIT@h - bne 3b - HMT_MEDIUM - lwarx r15,0,r14 - andis. r9,r15,PNV_CORE_IDLE_LOCK_BIT@h - bne- core_idle_lock_held +_GLOBAL(isa300_idle_stop_noloss) + mtspr SPRN_PSSCR,r3 + PPC_STOP + li r3,0 blr -/* Reuse some unused pt_regs slots for AMR/IAMR/UAMOR/UAMOR */ -#define PNV_POWERSAVE_AMR _TRAP -#define PNV_POWERSAVE_IAMR _DAR -#define PNV_POWERSAVE_UAMOR _DSISR -#define PNV_POWERSAVE_AMOR RESULT - /* - * Pass requested state in r3: - * r3 - PNV_THREAD_NAP/SLEEP/WINKLE in POWER8 - * - Requested PSSCR value in POWER9 + * Desired PSSCR in r3 + * + * GPRs may be lost, so they are saved here. Wakeup is by interrupt only. + * The SRESET wakeup returns to this function's caller by calling + * idle_return_gpr_loss with r3 set to desired return value. + * + * A wakeup without GPR loss may alteratively be handled as in + * isa300_idle_stop_noloss and blr directly, as an optimisation. * - * Address of idle handler to branch to in realmode in r4 + * The caller is responsible for saving/restoring SPRs, MSR, timebase, + * etc. */ -pnv_powersave_common: - /* Use r3 to pass state nap/sleep/winkle */ - /* NAP is a state loss, we create a regs frame on the - * stack, fill it up with the state we care about and - * stick a pointer to it in PACAR1. We really only - * need to save PC, some CR bits and the NV GPRs, - * but for now an interrupt frame will do. - */ - mtctr r4 - - mflr r0 - std r0,16(r1) - stdu r1,-INT_FRAME_SIZE(r1) - std r0,_LINK(r1) - std r0,_NIP(r1) - - /* We haven't lost state ... yet */ - li r0,0 - stb r0,PACA_NAPSTATELOST(r13) - - /* Continue saving state */ - SAVE_GPR(2, r1) - SAVE_NVGPRS(r1) - -BEGIN_FTR_SECTION - mfspr r4, SPRN_AMR - mfspr r5, SPRN_IAMR - mfspr r6, SPRN_UAMOR - std r4, PNV_POWERSAVE_AMR(r1) - std r5, PNV_POWERSAVE_IAMR(r1) - std r6, PNV_POWERSAVE_UAMOR(r1) -BEGIN_FTR_SECTION_NESTED(42) - mfspr r7, SPRN_AMOR - std r7, PNV_POWERSAVE_AMOR(r1) -END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE, 42) -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) - - mfcr r5 - std r5,_CCR(r1) +_GLOBAL(isa300_idle_stop_mayloss) + mtspr SPRN_PSSCR,r3 std r1,PACAR1(r13) - -BEGIN_FTR_SECTION - /* - * POWER9 does not require real mode to stop, and presently does not - * set hwthread_state for KVM (threads don't share MMU context), so - * we can remain in virtual mode for this. - */ - bctr -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) - /* - * POWER8 - * Go to real mode to do the nap, as required by the architecture. - * Also, we need to be in real mode before setting hwthread_state, - * because as soon as we do that, another thread can switch - * the MMU context to the guest. - */ - LOAD_REG_IMMEDIATE(r7, MSR_IDLE) - mtmsrd r7,0 - bctr - -/* - * This is the sequence required to execute idle instructions, as - * specified in ISA v2.07 (and earlier). MSR[IR] and MSR[DR] must be 0. - */ -#define IDLE_STATE_ENTER_SEQ_NORET(IDLE_INST) \ - /* Magic NAP/SLEEP/WINKLE mode enter sequence */ \ - std r0,0(r1); \ - ptesync; \ - ld r0,0(r1); \ -236: cmpd cr0,r0,r0; \ - bne 236b; \ - IDLE_INST; - - - .globl pnv_enter_arch207_idle_mode -pnv_enter_arch207_idle_mode: -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE - /* Tell KVM we're entering idle */ - li r4,KVM_HWTHREAD_IN_IDLE - /******************************************************/ - /* N O T E W E L L ! ! ! N O T E W E L L */ - /* The following store to HSTATE_HWTHREAD_STATE(r13) */ - /* MUST occur in real mode, i.e. with the MMU off, */ - /* and the MMU must stay off until we clear this flag */ - /* and test HSTATE_HWTHREAD_REQ(r13) in */ - /* pnv_powersave_wakeup in this file. */ - /* The reason is that another thread can switch the */ - /* MMU to a guest context whenever this flag is set */ - /* to KVM_HWTHREAD_IN_IDLE, and if the MMU was on, */ - /* that would potentially cause this thread to start */ - /* executing instructions from guest memory in */ - /* hypervisor mode, leading to a host crash or data */ - /* corruption, or worse. */ - /******************************************************/ - stb r4,HSTATE_HWTHREAD_STATE(r13) -#endif - stb r3,PACA_THREAD_IDLE_STATE(r13) - cmpwi cr3,r3,PNV_THREAD_SLEEP - bge cr3,2f - IDLE_STATE_ENTER_SEQ_NORET(PPC_NAP) - /* No return */ -2: - /* Sleep or winkle */ - lbz r7,PACA_THREAD_MASK(r13) - ld r14,PACA_CORE_IDLE_STATE_PTR(r13) - li r5,0 - beq cr3,3f - lis r5,PNV_CORE_IDLE_WINKLE_COUNT@h -3: -lwarx_loop1: - lwarx r15,0,r14 - - andis. r9,r15,PNV_CORE_IDLE_LOCK_BIT@h - bnel- core_idle_lock_held - - add r15,r15,r5 /* Add if winkle */ - andc r15,r15,r7 /* Clear thread bit */ - - andi. r9,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 or winkle */ - bgt cr3,enter_winkle - IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP) - -fastsleep_workaround_at_entry: - oris r15,r15,PNV_CORE_IDLE_LOCK_BIT@h - stwcx. r15,0,r14 - bne- lwarx_loop1 - isync - - /* Fast sleep workaround */ - li r3,1 - li r4,1 - bl opal_config_cpu_idle_state - - /* Unlock */ - xoris r15,r15,PNV_CORE_IDLE_LOCK_BIT@h - lwsync - stw r15,0(r14) - b common_enter - -enter_winkle: - bl save_sprs_to_stack - - IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE) - -/* - * r3 - PSSCR value corresponding to the requested stop state. - */ -power_enter_stop: -/* - * Check if we are executing the lite variant with ESLì=0 - */ - andis. r4,r3,PSSCR_EC_ESL_MASK_SHIFTED - clrldi r3,r3,60 /* r3 = Bits[60:63] = Requested Level (RL) */ - bne .Lhandle_esl_ec_set + mflr r4 + mfcr r5 + /* use stack red zone rather than a new frame for saving regs */ + std r2,-8*0(r1) + std r14,-8*1(r1) + std r15,-8*2(r1) + std r16,-8*3(r1) + std r17,-8*4(r1) + std r18,-8*5(r1) + std r19,-8*6(r1) + std r20,-8*7(r1) + std r21,-8*8(r1) + std r22,-8*9(r1) + std r23,-8*10(r1) + std r24,-8*11(r1) + std r25,-8*12(r1) + std r26,-8*13(r1) + std r27,-8*14(r1) + std r28,-8*15(r1) + std r29,-8*16(r1) + std r30,-8*17(r1) + std r31,-8*18(r1) + std r4,-8*19(r1) + std r5,-8*20(r1) + /* 168 bytes */ PPC_STOP - li r3,0 /* Since we didn't lose state, return 0 */ - std r3, PACA_REQ_PSSCR(r13) - - /* - * pnv_wakeup_noloss() expects r12 to contain the SRR1 value so - * it can determine if the wakeup reason is an HMI in - * CHECK_HMI_INTERRUPT. - * - * However, when we wakeup with ESL=0, SRR1 will not contain the wakeup - * reason, so there is no point setting r12 to SRR1. - * - * Further, we clear r12 here, so that we don't accidentally enter the - * HMI in pnv_wakeup_noloss() if the value of r12[42:45] = WAKE_HMI. - */ - li r12, 0 - b pnv_wakeup_noloss - -.Lhandle_esl_ec_set: -BEGIN_FTR_SECTION - /* - * POWER9 DD2.0 or earlier can incorrectly set PMAO when waking up after - * a state-loss idle. Saving and restoring MMCR0 over idle is a - * workaround. - */ - mfspr r4,SPRN_MMCR0 - std r4,_MMCR0(r1) -END_FTR_SECTION_IFCLR(CPU_FTR_POWER9_DD2_1) + b . /* catch bugs */ /* - * Check if the requested state is a deep idle state. - */ - LOAD_REG_ADDRBASE(r5,pnv_first_deep_stop_state) - ld r4,ADDROFF(pnv_first_deep_stop_state)(r5) - cmpd r3,r4 - bge .Lhandle_deep_stop - PPC_STOP /* Does not return (system reset interrupt) */ - -.Lhandle_deep_stop: -/* - * Entering deep idle state. - * Clear thread bit in PACA_CORE_IDLE_STATE, save SPRs to - * stack and enter stop - */ - lbz r7,PACA_THREAD_MASK(r13) - ld r14,PACA_CORE_IDLE_STATE_PTR(r13) - -lwarx_loop_stop: - lwarx r15,0,r14 - andis. r9,r15,PNV_CORE_IDLE_LOCK_BIT@h - bnel- core_idle_lock_held - andc r15,r15,r7 /* Clear thread bit */ - - stwcx. r15,0,r14 - bne- lwarx_loop_stop - isync - - bl save_sprs_to_stack - - PPC_STOP /* Does not return (system reset interrupt) */ - -/* - * Entered with MSR[EE]=0 and no soft-masked interrupts pending. - * r3 contains desired idle state (PNV_THREAD_NAP/SLEEP/WINKLE). - */ -_GLOBAL(power7_idle_insn) - /* Now check if user or arch enabled NAP mode */ - LOAD_REG_ADDR(r4, pnv_enter_arch207_idle_mode) - b pnv_powersave_common - -#define CHECK_HMI_INTERRUPT \ -BEGIN_FTR_SECTION_NESTED(66); \ - rlwinm r0,r12,45-31,0xf; /* extract wake reason field (P8) */ \ -FTR_SECTION_ELSE_NESTED(66); \ - rlwinm r0,r12,45-31,0xe; /* P7 wake reason field is 3 bits */ \ -ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 66); \ - cmpwi r0,0xa; /* Hypervisor maintenance ? */ \ - bne+ 20f; \ - /* Invoke opal call to handle hmi */ \ - ld r2,PACATOC(r13); \ - ld r1,PACAR1(r13); \ - std r3,ORIG_GPR3(r1); /* Save original r3 */ \ - li r3,0; /* NULL argument */ \ - bl hmi_exception_realmode; \ - nop; \ - ld r3,ORIG_GPR3(r1); /* Restore original r3 */ \ -20: nop; - -/* - * Entered with MSR[EE]=0 and no soft-masked interrupts pending. - * r3 contains desired PSSCR register value. + * Desired return value in r3 * - * Offline (CPU unplug) case also must notify KVM that the CPU is - * idle. - */ -_GLOBAL(power9_offline_stop) -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE - /* - * Tell KVM we're entering idle. - * This does not have to be done in real mode because the P9 MMU - * is independent per-thread. Some steppings share radix/hash mode - * between threads, but in that case KVM has a barrier sync in real - * mode before and after switching between radix and hash. - */ - li r4,KVM_HWTHREAD_IN_IDLE - stb r4,HSTATE_HWTHREAD_STATE(r13) -#endif - /* fall through */ - -_GLOBAL(power9_idle_stop) - std r3, PACA_REQ_PSSCR(r13) -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE -BEGIN_FTR_SECTION - sync - lwz r5, PACA_DONT_STOP(r13) - cmpwi r5, 0 - bne 1f -END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_XER_SO_BUG) -#endif - mtspr SPRN_PSSCR,r3 - LOAD_REG_ADDR(r4,power_enter_stop) - b pnv_powersave_common - /* No return */ -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE -1: - /* - * We get here when TM / thread reconfiguration bug workaround - * code wants to get the CPU into SMT4 mode, and therefore - * we are being asked not to stop. - */ - li r3, 0 - std r3, PACA_REQ_PSSCR(r13) - blr /* return 0 for wakeup cause / SRR1 value */ -#endif - -/* - * Called from machine check handler for powersave wakeups. - * Low level machine check processing has already been done. Now just - * go through the wake up path to get everything in order. + * The idle wakeup SRESET interrupt can call this after calling + * to return to the idle sleep function caller with r3 as the return code. * - * r3 - The original SRR1 value. - * Original SRR[01] have been clobbered. - * MSR_RI is clear. - */ -.global pnv_powersave_wakeup_mce -pnv_powersave_wakeup_mce: - /* Set cr3 for pnv_powersave_wakeup */ - rlwinm r11,r3,47-31,30,31 - cmpwi cr3,r11,2 - - /* - * Now put the original SRR1 with SRR1_WAKEMCE_RESVD as the wake - * reason into r12, which allows reuse of the system reset wakeup - * code without being mistaken for another type of wakeup. - */ - oris r12,r3,SRR1_WAKEMCE_RESVD@h - - b pnv_powersave_wakeup - -/* - * Called from reset vector for powersave wakeups. - * cr3 - set to gt if waking up with partial/complete hypervisor state loss - * r12 - SRR1 + * This must not be used if idle was entered via a _noloss function (use + * a simple blr instead). */ -.global pnv_powersave_wakeup -pnv_powersave_wakeup: - ld r2, PACATOC(r13) - -BEGIN_FTR_SECTION - bl pnv_restore_hyp_resource_arch300 -FTR_SECTION_ELSE - bl pnv_restore_hyp_resource_arch207 -ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300) - - li r0,PNV_THREAD_RUNNING - stb r0,PACA_THREAD_IDLE_STATE(r13) /* Clear thread state */ - - mr r3,r12 - +_GLOBAL(idle_return_gpr_loss) #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE lbz r0,HSTATE_HWTHREAD_STATE(r13) cmpwi r0,KVM_HWTHREAD_IN_KERNEL @@ -547,449 +106,105 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300) beq 1f b kvm_start_guest 1: + lbz r0,PACA_NAPSTATELOST(r13) + cmpwi r0,0 + bne 2f + bltlr cr1 +2: #endif - - /* Return SRR1 from power7_nap() */ - blt cr3,pnv_wakeup_noloss - b pnv_wakeup_loss + ld r1,PACAR1(r13) + ld r4,-8*19(r1) + ld r5,-8*20(r1) + mtlr r4 + mtcr r5 + /* + * KVM nap requires r2 to be saved, rather than just restoring it + * from PACATOC. This could be avoided for that less common case + * if KVM saved its r2. + */ + ld r2,-8*0(r1) + ld r14,-8*1(r1) + ld r15,-8*2(r1) + ld r16,-8*3(r1) + ld r17,-8*4(r1) + ld r18,-8*5(r1) + ld r19,-8*6(r1) + ld r20,-8*7(r1) + ld r21,-8*8(r1) + ld r22,-8*9(r1) + ld r23,-8*10(r1) + ld r24,-8*11(r1) + ld r25,-8*12(r1) + ld r26,-8*13(r1) + ld r27,-8*14(r1) + ld r28,-8*15(r1) + ld r29,-8*16(r1) + ld r30,-8*17(r1) + ld r31,-8*18(r1) + blr /* - * Check whether we have woken up with hypervisor state loss. - * If yes, restore hypervisor state and return back to link. + * This is the sequence required to execute idle instructions, as + * specified in ISA v2.07 (and earlier). MSR[IR] and MSR[DR] must be 0. * - * cr3 - set to gt if waking up with partial/complete hypervisor state loss + * The 0(r1) slot is used to save r2 in isa206, so use that here. */ -pnv_restore_hyp_resource_arch300: - /* - * Workaround for POWER9, if we lost resources, the ERAT - * might have been mixed up and needs flushing. We also need - * to reload MMCR0 (see comment above). We also need to set - * then clear bit 60 in MMCRA to ensure the PMU starts running. - */ - blt cr3,1f -BEGIN_FTR_SECTION - PPC_INVALIDATE_ERAT - ld r1,PACAR1(r13) - ld r4,_MMCR0(r1) - mtspr SPRN_MMCR0,r4 -END_FTR_SECTION_IFCLR(CPU_FTR_POWER9_DD2_1) - mfspr r4,SPRN_MMCRA - ori r4,r4,(1 << (63-60)) - mtspr SPRN_MMCRA,r4 - xori r4,r4,(1 << (63-60)) - mtspr SPRN_MMCRA,r4 -1: - /* - * POWER ISA 3. Use PSSCR to determine if we - * are waking up from deep idle state - */ - LOAD_REG_ADDRBASE(r5,pnv_first_deep_stop_state) - ld r4,ADDROFF(pnv_first_deep_stop_state)(r5) - - /* - * 0-3 bits correspond to Power-Saving Level Status - * which indicates the idle state we are waking up from - */ - mfspr r5, SPRN_PSSCR - rldicl r5,r5,4,60 - li r0, 0 /* clear requested_psscr to say we're awake */ - std r0, PACA_REQ_PSSCR(r13) - cmpd cr4,r5,r4 - bge cr4,pnv_wakeup_tb_loss /* returns to caller */ - - blr /* Waking up without hypervisor state loss. */ - -/* Same calling convention as arch300 */ -pnv_restore_hyp_resource_arch207: - /* - * POWER ISA 2.07 or less. - * Check if we slept with sleep or winkle. - */ - lbz r4,PACA_THREAD_IDLE_STATE(r13) - cmpwi cr2,r4,PNV_THREAD_NAP - bgt cr2,pnv_wakeup_tb_loss /* Either sleep or Winkle */ - - /* - * We fall through here if PACA_THREAD_IDLE_STATE shows we are waking - * up from nap. At this stage CR3 shouldn't contains 'gt' since that - * indicates we are waking with hypervisor state loss from nap. - */ - bgt cr3,. - - blr /* Waking up without hypervisor state loss */ +#define IDLE_STATE_ENTER_SEQ_NORET(IDLE_INST) \ + /* Magic NAP/SLEEP/WINKLE mode enter sequence */ \ + std r2,0(r1); \ + ptesync; \ + ld r2,0(r1); \ +236: cmpd cr0,r2,r2; \ + bne 236b; \ + IDLE_INST; \ + b . /* catch bugs */ /* - * Called if waking up from idle state which can cause either partial or - * complete hyp state loss. - * In POWER8, called if waking up from fastsleep or winkle - * In POWER9, called if waking up from stop state >= pnv_first_deep_stop_state + * Desired instruction type in r3 * - * r13 - PACA - * cr3 - gt if waking up with partial/complete hypervisor state loss + * GPRs may be lost, so they are saved here. Wakeup is by interrupt only. + * The SRESET wakeup returns to this function's caller by calling + * idle_return_gpr_loss with r3 set to desired return value. * - * If ISA300: - * cr4 - gt or eq if waking up from complete hypervisor state loss. + * A wakeup without GPR loss may alteratively be handled as in + * isa300_idle_stop_noloss and blr directly, as an optimisation. * - * If ISA207: - * r4 - PACA_THREAD_IDLE_STATE - */ -pnv_wakeup_tb_loss: - ld r1,PACAR1(r13) - /* - * Before entering any idle state, the NVGPRs are saved in the stack. - * If there was a state loss, or PACA_NAPSTATELOST was set, then the - * NVGPRs are restored. If we are here, it is likely that state is lost, - * but not guaranteed -- neither ISA207 nor ISA300 tests to reach - * here are the same as the test to restore NVGPRS: - * PACA_THREAD_IDLE_STATE test for ISA207, PSSCR test for ISA300, - * and SRR1 test for restoring NVGPRs. - * - * We are about to clobber NVGPRs now, so set NAPSTATELOST to - * guarantee they will always be restored. This might be tightened - * with careful reading of specs (particularly for ISA300) but this - * is already a slow wakeup path and it's simpler to be safe. - */ - li r0,1 - stb r0,PACA_NAPSTATELOST(r13) - - /* - * - * Save SRR1 and LR in NVGPRs as they might be clobbered in - * opal_call() (called in CHECK_HMI_INTERRUPT). SRR1 is required - * to determine the wakeup reason if we branch to kvm_start_guest. LR - * is required to return back to reset vector after hypervisor state - * restore is complete. - */ - mr r19,r12 - mr r18,r4 - mflr r17 -BEGIN_FTR_SECTION - CHECK_HMI_INTERRUPT -END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) - - ld r14,PACA_CORE_IDLE_STATE_PTR(r13) - lbz r7,PACA_THREAD_MASK(r13) - - /* - * Take the core lock to synchronize against other threads. - * - * 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. - */ -1: - lwarx r15,0,r14 - andis. r9,r15,PNV_CORE_IDLE_LOCK_BIT@h - bnel- core_idle_lock_held - oris r15,r15,PNV_CORE_IDLE_LOCK_BIT@h - stwcx. r15,0,r14 - bne- 1b - isync - - andi. r9,r15,PNV_CORE_IDLE_THREAD_BITS - cmpwi cr2,r9,0 - - /* - * At this stage - * cr2 - eq if first thread to wakeup in core - * cr3- gt if waking up with partial/complete hypervisor state loss - * ISA300: - * cr4 - gt or eq if waking up from complete hypervisor state loss. - */ - -BEGIN_FTR_SECTION - /* - * Were we in winkle? - * If yes, check if all threads were in winkle, decrement our - * winkle count, set all thread winkle bits if all were in winkle. - * Check if our thread has a winkle bit set, and set cr4 accordingly - * (to match ISA300, above). Pseudo-code for core idle state - * transitions for ISA207 is as follows (everything happens atomically - * due to store conditional and/or lock bit): - * - * nap_idle() { } - * nap_wake() { } - * - * sleep_idle() - * { - * core_idle_state &= ~thread_in_core - * } - * - * sleep_wake() - * { - * bool first_in_core, first_in_subcore; - * - * first_in_core = (core_idle_state & IDLE_THREAD_BITS) = 0; - * first_in_subcore = (core_idle_state & SUBCORE_SIBLING_MASK) = 0; - * - * core_idle_state |= thread_in_core; - * } - * - * winkle_idle() - * { - * core_idle_state &= ~thread_in_core; - * core_idle_state += 1 << WINKLE_COUNT_SHIFT; - * } - * - * winkle_wake() - * { - * bool first_in_core, first_in_subcore, winkle_state_lost; - * - * first_in_core = (core_idle_state & IDLE_THREAD_BITS) = 0; - * first_in_subcore = (core_idle_state & SUBCORE_SIBLING_MASK) = 0; - * - * core_idle_state |= thread_in_core; - * - * if ((core_idle_state & WINKLE_MASK) = (8 << WINKLE_COUNT_SIHFT)) - * core_idle_state |= THREAD_WINKLE_BITS; - * core_idle_state -= 1 << WINKLE_COUNT_SHIFT; - * - * winkle_state_lost = core_idle_state & - * (thread_in_core << WINKLE_THREAD_SHIFT); - * core_idle_state &= ~(thread_in_core << WINKLE_THREAD_SHIFT); - * } - * - */ - cmpwi r18,PNV_THREAD_WINKLE - bne 2f - andis. r9,r15,PNV_CORE_IDLE_WINKLE_COUNT_ALL_BIT@h - subis r15,r15,PNV_CORE_IDLE_WINKLE_COUNT@h - beq 2f - ori r15,r15,PNV_CORE_IDLE_THREAD_WINKLE_BITS /* all were winkle */ -2: - /* Shift thread bit to winkle mask, then test if this thread is set, - * and remove it from the winkle bits */ - slwi r8,r7,8 - and r8,r8,r15 - andc r15,r15,r8 - cmpwi cr4,r8,1 /* cr4 will be gt if our bit is set, lt if not */ - - lbz r4,PACA_SUBCORE_SIBLING_MASK(r13) - and r4,r4,r15 - cmpwi r4,0 /* Check if first in subcore */ - - or r15,r15,r7 /* Set thread bit */ - beq first_thread_in_subcore -END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) - - or r15,r15,r7 /* Set thread bit */ - beq cr2,first_thread_in_core - - /* Not first thread in core or subcore to wake up */ - b clear_lock - -first_thread_in_subcore: - /* - * If waking up from sleep, subcore state is not lost. Hence - * skip subcore state restore - */ - blt cr4,subcore_state_restored - - /* Restore per-subcore state */ - ld r4,_SDR1(r1) - mtspr SPRN_SDR1,r4 - - ld r4,_RPR(r1) - mtspr SPRN_RPR,r4 - ld r4,_AMOR(r1) - mtspr SPRN_AMOR,r4 - -subcore_state_restored: - /* - * Check if the thread is also the first thread in the core. If not, - * skip to clear_lock. - */ - bne cr2,clear_lock - -first_thread_in_core: - - /* - * First thread in the core waking up from any state which can cause - * partial or complete hypervisor state loss. 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 if the platform does not have fastsleep or does not - * require the workaround. Patching will be performed during the - * discovery of idle-states. - */ -.global pnv_fastsleep_workaround_at_exit -pnv_fastsleep_workaround_at_exit: - b fastsleep_workaround_at_exit - -timebase_resync: - /* - * Use cr3 which indicates that we are waking up with atleast partial - * hypervisor state loss to determine if TIMEBASE RESYNC is needed. - */ - ble cr3,.Ltb_resynced - /* Time base re-sync */ - bl opal_resync_timebase; - /* - * If waking up from sleep (POWER8), per core state - * is not lost, skip to clear_lock. - */ -.Ltb_resynced: - blt cr4,clear_lock - - /* - * First thread in the core to wake up and its waking up with - * complete hypervisor state loss. Restore per core hypervisor - * state. - */ -BEGIN_FTR_SECTION - ld r4,_PTCR(r1) - mtspr SPRN_PTCR,r4 - ld r4,_RPR(r1) - mtspr SPRN_RPR,r4 - ld r4,_AMOR(r1) - mtspr SPRN_AMOR,r4 -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) - - ld r4,_TSCR(r1) - mtspr SPRN_TSCR,r4 - ld r4,_WORC(r1) - mtspr SPRN_WORC,r4 - -clear_lock: - xoris r15,r15,PNV_CORE_IDLE_LOCK_BIT@h - lwsync - stw r15,0(r14) - -common_exit: - /* - * Common to all threads. - * - * If waking up from sleep, hypervisor state is not lost. Hence - * skip hypervisor state restore. - */ - blt cr4,hypervisor_state_restored - - /* Waking up from winkle */ - -BEGIN_MMU_FTR_SECTION - b no_segments -END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX) - /* Restore SLB from PACA */ - ld r8,PACA_SLBSHADOWPTR(r13) - - .rept SLB_NUM_BOLTED - li r3, SLBSHADOW_SAVEAREA - LDX_BE r5, r8, r3 - addi r3, r3, 8 - LDX_BE r6, r8, r3 - andis. r7,r5,SLB_ESID_V@h - beq 1f - slbmte r6,r5 -1: addi r8,r8,16 - .endr -no_segments: - - /* Restore per thread state */ - - ld r4,_SPURR(r1) - mtspr SPRN_SPURR,r4 - ld r4,_PURR(r1) - mtspr SPRN_PURR,r4 - ld r4,_DSCR(r1) - mtspr SPRN_DSCR,r4 - ld r4,_WORT(r1) - mtspr SPRN_WORT,r4 - - /* Call cur_cpu_spec->cpu_restore() */ - LOAD_REG_ADDR(r4, cur_cpu_spec) - ld r4,0(r4) - ld r12,CPU_SPEC_RESTORE(r4) -#ifdef PPC64_ELF_ABI_v1 - ld r12,0(r12) -#endif - mtctr r12 - bctrl - -/* - * On POWER9, we can come here on wakeup from a cpuidle stop state. - * Hence restore the additional SPRs to the saved value. + * The caller is responsible for saving/restoring SPRs, MSR, timebase, + * etc. * - * On POWER8, we come here only on winkle. Since winkle is used - * only in the case of CPU-Hotplug, we don't need to restore - * the additional SPRs. + * This must be called in real-mode (MSR_IDLE). */ -BEGIN_FTR_SECTION - bl power9_restore_additional_sprs -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) -hypervisor_state_restored: - - mr r12,r19 - mtlr r17 - blr /* return to pnv_powersave_wakeup */ - -fastsleep_workaround_at_exit: - li r3,1 - li r4,0 - bl opal_config_cpu_idle_state - b timebase_resync - -/* - * R3 here contains the value that will be returned to the caller - * of power7_nap. - * R12 contains SRR1 for CHECK_HMI_INTERRUPT. - */ -.global pnv_wakeup_loss -pnv_wakeup_loss: - ld r1,PACAR1(r13) -BEGIN_FTR_SECTION - CHECK_HMI_INTERRUPT -END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) - REST_NVGPRS(r1) - REST_GPR(2, r1) - -BEGIN_FTR_SECTION - /* These regs were saved in pnv_powersave_common() */ - ld r4, PNV_POWERSAVE_AMR(r1) - ld r5, PNV_POWERSAVE_IAMR(r1) - ld r6, PNV_POWERSAVE_UAMOR(r1) - mtspr SPRN_AMR, r4 - mtspr SPRN_IAMR, r5 - mtspr SPRN_UAMOR, r6 -BEGIN_FTR_SECTION_NESTED(42) - ld r7, PNV_POWERSAVE_AMOR(r1) - mtspr SPRN_AMOR, r7 -END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE, 42) - /* - * We don't need an isync here after restoring IAMR because the upcoming - * mtmsrd is execution synchronizing. - */ -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) - - ld r4,PACAKMSR(r13) - ld r5,_LINK(r1) - ld r6,_CCR(r1) - addi r1,r1,INT_FRAME_SIZE - mtlr r5 - mtcr r6 - mtmsrd r4 - blr +_GLOBAL(isa206_idle_insn_mayloss) + std r1,PACAR1(r13) + mflr r4 + mfcr r5 + /* use stack red zone rather than a new frame for saving regs */ + std r2,-8*0(r1) + std r14,-8*1(r1) + std r15,-8*2(r1) + std r16,-8*3(r1) + std r17,-8*4(r1) + std r18,-8*5(r1) + std r19,-8*6(r1) + std r20,-8*7(r1) + std r21,-8*8(r1) + std r22,-8*9(r1) + std r23,-8*10(r1) + std r24,-8*11(r1) + std r25,-8*12(r1) + std r26,-8*13(r1) + std r27,-8*14(r1) + std r28,-8*15(r1) + std r29,-8*16(r1) + std r30,-8*17(r1) + std r31,-8*18(r1) + std r4,-8*19(r1) + std r5,-8*20(r1) + cmpwi r3,PNV_THREAD_NAP + bne 1f + IDLE_STATE_ENTER_SEQ_NORET(PPC_NAP) +1: cmpwi r3,PNV_THREAD_SLEEP + bne 2f + IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP) +2: IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE) -/* - * R3 here contains the value that will be returned to the caller - * of power7_nap. - * R12 contains SRR1 for CHECK_HMI_INTERRUPT. - */ -pnv_wakeup_noloss: - lbz r0,PACA_NAPSTATELOST(r13) - cmpwi r0,0 - bne pnv_wakeup_loss - ld r1,PACAR1(r13) -BEGIN_FTR_SECTION - CHECK_HMI_INTERRUPT -END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) - ld r4,PACAKMSR(r13) - ld r5,_NIP(r1) - ld r6,_CCR(r1) - addi r1,r1,INT_FRAME_SIZE - mtlr r5 - mtcr r6 - mtmsrd r4 - blr diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 1729bf409562..70dc10aa0ccf 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -401,8 +401,8 @@ void __init check_for_initrd(void) #ifdef CONFIG_SMP -int threads_per_core, threads_per_subcore, threads_shift; -cpumask_t threads_core_mask; +int threads_per_core, threads_per_subcore, threads_shift __read_mostly; +cpumask_t threads_core_mask __read_mostly; EXPORT_SYMBOL_GPL(threads_per_core); EXPORT_SYMBOL_GPL(threads_per_subcore); EXPORT_SYMBOL_GPL(threads_shift); diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 3a5e719ef032..58d0f1ba845d 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -448,8 +448,10 @@ kvm_no_guest: rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1 mtspr SPRN_LPCR, r4 li r3, 0 - mfspr r12,SPRN_SRR1 - b pnv_wakeup_loss + /* set up cr3 and r3 for return */ + cmpdi cr3, r3, 0 + mfspr r3,SPRN_SRR1 + b idle_return_gpr_loss 53: HMT_LOW ld r5, HSTATE_KVM_VCORE(r13) diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c index e52f9b06dd9c..182112fd845a 100644 --- a/arch/powerpc/platforms/powernv/idle.c +++ b/arch/powerpc/platforms/powernv/idle.c @@ -16,6 +16,7 @@ #include <linux/device.h> #include <linux/cpu.h> +#include <asm/asm-prototypes.h> #include <asm/firmware.h> #include <asm/machdep.h> #include <asm/opal.h> @@ -48,10 +49,10 @@ static u64 pnv_default_stop_mask; static bool default_stop_found; /* - * First deep stop state. Used to figure out when to save/restore - * hypervisor context. + * First stop state levels when SPR and TB loss can occur. */ -u64 pnv_first_deep_stop_state = MAX_STOP_STATE; +static u64 pnv_first_tb_loss_level = MAX_STOP_STATE + 1; +static u64 pnv_first_spr_loss_level = MAX_STOP_STATE + 1; /* * psscr value and mask of the deepest stop idle state. @@ -62,6 +63,8 @@ static u64 pnv_deepest_stop_psscr_mask; static u64 pnv_deepest_stop_flag; static bool deepest_stop_found; +static unsigned long power7_offline_type; + static int pnv_save_sprs_for_deep_states(void) { int cpu; @@ -72,12 +75,12 @@ static int pnv_save_sprs_for_deep_states(void) * all cpus at boot. Get these reg values of current cpu and use the * same across all cpus. */ - uint64_t lpcr_val = mfspr(SPRN_LPCR); - uint64_t hid0_val = mfspr(SPRN_HID0); - uint64_t hid1_val = mfspr(SPRN_HID1); - uint64_t hid4_val = mfspr(SPRN_HID4); - uint64_t hid5_val = mfspr(SPRN_HID5); - uint64_t hmeer_val = mfspr(SPRN_HMEER); + uint64_t lpcr_val = mfspr(SPRN_LPCR); + uint64_t hid0_val = mfspr(SPRN_HID0); + uint64_t hid1_val = mfspr(SPRN_HID1); + uint64_t hid4_val = mfspr(SPRN_HID4); + uint64_t hid5_val = mfspr(SPRN_HID5); + uint64_t hmeer_val = mfspr(SPRN_HMEER); uint64_t msr_val = MSR_IDLE; uint64_t psscr_val = pnv_deepest_stop_psscr_val; @@ -137,89 +140,6 @@ static int pnv_save_sprs_for_deep_states(void) return 0; } -static void pnv_alloc_idle_core_states(void) -{ - int i, j; - int nr_cores = cpu_nr_cores(); - u32 *core_idle_state; - - /* - * core_idle_state - The lower 8 bits track the idle state of - * each thread of the core. - * - * The most significant bit is the lock bit. - * - * Initially all the bits corresponding to threads_per_core - * are set. They are cleared when the thread enters deep idle - * state like sleep and winkle/stop. - * - * Initially the lock bit is cleared. The lock bit has 2 - * purposes: - * a. While the first thread in the core waking up from - * idle is restoring core state, it prevents other - * threads in the core from switching to process - * context. - * b. While the last thread in the core is saving the - * core state, it prevents a different thread from - * waking up. - */ - for (i = 0; i < nr_cores; i++) { - int first_cpu = i * threads_per_core; - int node = cpu_to_node(first_cpu); - size_t paca_ptr_array_size; - - core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, node); - *core_idle_state = (1 << threads_per_core) - 1; - paca_ptr_array_size = (threads_per_core * - sizeof(struct paca_struct *)); - - for (j = 0; j < threads_per_core; j++) { - int cpu = first_cpu + j; - - paca_ptrs[cpu]->core_idle_state_ptr = core_idle_state; - paca_ptrs[cpu]->thread_idle_state = PNV_THREAD_RUNNING; - paca_ptrs[cpu]->thread_mask = 1 << j; - } - } - - update_subcore_sibling_mask(); - - if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT) { - int rc = pnv_save_sprs_for_deep_states(); - - if (likely(!rc)) - return; - - /* - * The stop-api is unable to restore hypervisor - * resources on wakeup from platform idle states which - * lose full context. So disable such states. - */ - supported_cpuidle_states &= ~OPAL_PM_LOSE_FULL_CONTEXT; - pr_warn("cpuidle-powernv: Disabling idle states that lose full context\n"); - pr_warn("cpuidle-powernv: Idle power-savings, CPU-Hotplug affected\n"); - - if (cpu_has_feature(CPU_FTR_ARCH_300) && - (pnv_deepest_stop_flag & OPAL_PM_LOSE_FULL_CONTEXT)) { - /* - * Use the default stop state for CPU-Hotplug - * if available. - */ - if (default_stop_found) { - pnv_deepest_stop_psscr_val - pnv_default_stop_val; - pnv_deepest_stop_psscr_mask - pnv_default_stop_mask; - pr_warn("cpuidle-powernv: Offlined CPUs will stop with psscr = 0x%016llx\n", - pnv_deepest_stop_psscr_val); - } else { /* Fallback to snooze loop for CPU-Hotplug */ - deepest_stop_found = false; - pr_warn("cpuidle-powernv: Offlined CPUs will busy wait\n"); - } - } - } -} - u32 pnv_get_supported_cpuidle_states(void) { return supported_cpuidle_states; @@ -238,6 +158,9 @@ static void pnv_fastsleep_workaround_apply(void *info) *err = 1; } +static bool power7_fastsleep_workaround_entry = true; +static bool power7_fastsleep_workaround_exit = true; + /* * Used to store fastsleep workaround state * 0 - Workaround applied/undone at fastsleep entry/exit path (Default) @@ -269,21 +192,15 @@ static ssize_t store_fastsleep_workaround_applyonce(struct device *dev, * fastsleep_workaround_applyonce = 1 implies * fastsleep workaround needs to be left in 'applied' state on all * the cores. Do this by- - * 1. Patching out the call to 'undo' workaround in fastsleep exit path - * 2. Sending ipi to all the cores which have at least one online thread - * 3. Patching out the call to 'apply' workaround in fastsleep entry - * path + * 1. Disable the 'undo' workaround in fastsleep exit path + * 2. Sendi IPIs to all the cores which have at least one online thread + * 3. Disable the 'apply' workaround in fastsleep entry path + * * There is no need to send ipi to cores which have all threads * offlined, as last thread of the core entering fastsleep or deeper * state would have applied workaround. */ - err = patch_instruction( - (unsigned int *)pnv_fastsleep_workaround_at_exit, - PPC_INST_NOP); - if (err) { - pr_err("fastsleep_workaround_applyonce change failed while patching pnv_fastsleep_workaround_at_exit"); - goto fail; - } + power7_fastsleep_workaround_exit = false; get_online_cpus(); primary_thread_mask = cpu_online_cores_map(); @@ -296,13 +213,7 @@ static ssize_t store_fastsleep_workaround_applyonce(struct device *dev, goto fail; } - err = patch_instruction( - (unsigned int *)pnv_fastsleep_workaround_at_entry, - PPC_INST_NOP); - if (err) { - pr_err("fastsleep_workaround_applyonce change failed while patching pnv_fastsleep_workaround_at_entry"); - goto fail; - } + power7_fastsleep_workaround_entry = false; fastsleep_workaround_applyonce = 1; @@ -315,27 +226,336 @@ static DEVICE_ATTR(fastsleep_workaround_applyonce, 0600, show_fastsleep_workaround_applyonce, store_fastsleep_workaround_applyonce); -static unsigned long __power7_idle_type(unsigned long type) +static inline void atomic_start_thread_idle(void) { + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + int thread_nr = cpu_thread_in_core(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + + clear_bit(thread_nr, state); +} + +static inline void atomic_stop_thread_idle(void) +{ + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + int thread_nr = cpu_thread_in_core(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + + set_bit(thread_nr, state); +} + +static inline void atomic_lock_thread_idle(void) +{ + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + + while (unlikely(test_and_set_bit_lock(NR_PNV_CORE_IDLE_LOCK_BIT, state))) + barrier(); +} + +static inline void atomic_unlock_and_stop_thread_idle(void) +{ + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + unsigned long thread = 1UL << cpu_thread_in_core(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + u64 s = READ_ONCE(*state); + u64 new, tmp; + + BUG_ON(!(s & PNV_CORE_IDLE_LOCK_BIT)); + BUG_ON(s & thread); + +again: + new = (s | thread) & ~PNV_CORE_IDLE_LOCK_BIT; + tmp = cmpxchg(state, s, new); + if (unlikely(tmp != s)) { + s = tmp; + goto again; + } +} + +static inline void atomic_unlock_thread_idle(void) +{ + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + + BUG_ON(!test_bit(NR_PNV_CORE_IDLE_LOCK_BIT, state)); + clear_bit_unlock(NR_PNV_CORE_IDLE_LOCK_BIT, state); +} + +/* P7 and P8 */ +struct p7_sprs { + /* per core */ + u64 tscr; + u64 worc; + + /* per subcore */ + u64 sdr1; + u64 rpr; + + /* per thread */ + u64 lpcr; + u64 hfscr; + u64 fscr; + u64 purr; + u64 spurr; + u64 dscr; + u64 wort; + + /* per thread SPRs that get lost in shallow states */ + u64 amr; + u64 iamr; + u64 amor; + u64 uamor; +}; + +static unsigned long power7_idle_insn(unsigned long type) +{ + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + unsigned long thread = 1UL << cpu_thread_in_core(cpu); + unsigned long core_thread_mask = (1UL << threads_per_core) - 1; unsigned long srr1; + bool full_winkle; + struct p7_sprs sprs = {}; /* avoid false use-uninitialised */ + bool sprs_saved = false; + int rc; - if (!prep_irq_for_idle_irqsoff()) - return 0; + if (unlikely(type != PNV_THREAD_NAP)) { + atomic_lock_thread_idle(); + + BUG_ON(!(*state & thread)); + *state &= ~thread; + + if (power7_fastsleep_workaround_entry) { + if ((*state & core_thread_mask) = 0) { + rc = opal_config_cpu_idle_state( + OPAL_CONFIG_IDLE_FASTSLEEP, + OPAL_CONFIG_IDLE_APPLY); + BUG_ON(rc); + } + } + + if (type = PNV_THREAD_WINKLE) { + sprs.tscr = mfspr(SPRN_TSCR); + sprs.worc = mfspr(SPRN_WORC); + + sprs.sdr1 = mfspr(SPRN_SDR1); + sprs.rpr = mfspr(SPRN_RPR); + + sprs.lpcr = mfspr(SPRN_LPCR); + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + sprs.hfscr = mfspr(SPRN_HFSCR); + sprs.fscr = mfspr(SPRN_FSCR); + } + sprs.purr = mfspr(SPRN_PURR); + sprs.spurr = mfspr(SPRN_SPURR); + sprs.dscr = mfspr(SPRN_DSCR); + sprs.wort = mfspr(SPRN_WORT); + + sprs_saved = true; + + /* + * Increment winkle counter and set all winkle bits if + * all threads are winkling. This allows wakeup side to + * distinguish between fast sleep and winkle state + * loss. Fast sleep still has to resync the timebase so + * this may not be a really big win. + */ + *state += 1 << PNV_CORE_IDLE_WINKLE_COUNT_SHIFT; + if ((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) + >> PNV_CORE_IDLE_WINKLE_COUNT_SHIFT + = threads_per_core) + *state |= PNV_CORE_IDLE_THREAD_WINKLE_BITS; + WARN_ON((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) = 0); + } + + atomic_unlock_thread_idle(); + } + + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + sprs.amr = mfspr(SPRN_AMR); + sprs.iamr = mfspr(SPRN_IAMR); + sprs.amor = mfspr(SPRN_AMOR); + sprs.uamor = mfspr(SPRN_UAMOR); + } + + local_paca->thread_idle_state = type; + srr1 = isa206_idle_insn_mayloss(type); /* go idle */ + local_paca->thread_idle_state = PNV_THREAD_RUNNING; + + WARN_ON_ONCE(!srr1); + WARN_ON_ONCE(mfmsr() & (MSR_IR|MSR_DR)); + + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + if ((srr1 & SRR1_WAKESTATE) != SRR1_WS_NOLOSS) { + /* + * We don't need an isync after the mtsprs here because + * the upcoming mtmsrd is execution synchronizing. + */ + mtspr(SPRN_AMR, sprs.amr); + mtspr(SPRN_IAMR, sprs.iamr); + mtspr(SPRN_AMOR, sprs.amor); + mtspr(SPRN_UAMOR, sprs.uamor); + } + } + + if (unlikely((srr1 & SRR1_WAKEMASK_P8) = SRR1_WAKEHMI)) + hmi_exception_realmode(NULL); + + if (likely((srr1 & SRR1_WAKESTATE) != SRR1_WS_HVLOSS)) { + if (unlikely(type != PNV_THREAD_NAP)) { + atomic_lock_thread_idle(); + if (type = PNV_THREAD_WINKLE) { + WARN_ON((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) = 0); + *state -= 1 << PNV_CORE_IDLE_WINKLE_COUNT_SHIFT; + *state &= ~(thread << PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT); + } + atomic_unlock_and_stop_thread_idle(); + } + return srr1; + } + + /* HV state loss */ + BUG_ON(type = PNV_THREAD_NAP); + + atomic_lock_thread_idle(); + + full_winkle = false; + if (type = PNV_THREAD_WINKLE) { + WARN_ON((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) = 0); + *state -= 1 << PNV_CORE_IDLE_WINKLE_COUNT_SHIFT; + if (*state & (thread << PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT)) { + *state &= ~(thread << PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT); + full_winkle = true; + BUG_ON(!sprs_saved); + } + } + + WARN_ON(*state & thread); + + if ((*state & core_thread_mask) != 0) + goto core_woken; + + /* Per-core SPRs */ + if (full_winkle) { + mtspr(SPRN_TSCR, sprs.tscr); + mtspr(SPRN_WORC, sprs.worc); + } + + if (power7_fastsleep_workaround_exit) { + rc = opal_config_cpu_idle_state(OPAL_CONFIG_IDLE_FASTSLEEP, + OPAL_CONFIG_IDLE_UNDO); + BUG_ON(rc); + } + + /* TB */ + if (opal_resync_timebase() != OPAL_SUCCESS) + BUG(); + +core_woken: + if (!full_winkle) + goto subcore_woken; + + if ((*state & local_paca->subcore_sibling_mask) != 0) + goto subcore_woken; + + /* Per-subcore SPRs */ + mtspr(SPRN_SDR1, sprs.sdr1); + mtspr(SPRN_RPR, sprs.rpr); + +subcore_woken: + /* + * isync after restoring shared SPRs and before unlocking. Unlock + * only contains hwsync which does not necessarily do the right + * thing for SPRs. + */ + isync(); + atomic_unlock_and_stop_thread_idle(); + + /* Fast sleep does not lose SPRs */ + if (!full_winkle) + return srr1; + + /* Per-thread SPRs */ + mtspr(SPRN_LPCR, sprs.lpcr); + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + mtspr(SPRN_HFSCR, sprs.hfscr); + mtspr(SPRN_FSCR, sprs.fscr); + } + mtspr(SPRN_PURR, sprs.purr); + mtspr(SPRN_SPURR, sprs.spurr); + mtspr(SPRN_DSCR, sprs.dscr); + mtspr(SPRN_WORT, sprs.wort); + + mtspr(SPRN_SPRG3, local_paca->sprg_vdso); + + /* + * The SLB has to be restored here, but it sometimes still + * contains entries, so the __ variant must be used to prevent + * multi hits. + */ + __slb_restore_bolted_realmode(); + + return srr1; +} + +#ifdef CONFIG_HOTPLUG_CPU +static unsigned long power7_offline(void) +{ + unsigned long srr1; + + mtmsr(MSR_IDLE); + +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + /* Tell KVM we're entering idle. */ + /******************************************************/ + /* N O T E W E L L ! ! ! N O T E W E L L */ + /* The following store to HSTATE_HWTHREAD_STATE(r13) */ + /* MUST occur in real mode, i.e. with the MMU off, */ + /* and the MMU must stay off until we clear this flag */ + /* and test HSTATE_HWTHREAD_REQ(r13) in */ + /* pnv_powersave_wakeup in this file. */ + /* The reason is that another thread can switch the */ + /* MMU to a guest context whenever this flag is set */ + /* to KVM_HWTHREAD_IN_IDLE, and if the MMU was on, */ + /* that would potentially cause this thread to start */ + /* executing instructions from guest memory in */ + /* hypervisor mode, leading to a host crash or data */ + /* corruption, or worse. */ + /******************************************************/ + local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_IDLE; +#endif __ppc64_runlatch_off(); - srr1 = power7_idle_insn(type); + srr1 = power7_idle_insn(power7_offline_type); __ppc64_runlatch_on(); - fini_irq_for_idle_irqsoff(); + mtmsr(MSR_KERNEL); return srr1; } +#endif void power7_idle_type(unsigned long type) { unsigned long srr1; - srr1 = __power7_idle_type(type); + if (!prep_irq_for_idle_irqsoff()) + return; + + mtmsr(MSR_IDLE); + __ppc64_runlatch_off(); + srr1 = power7_idle_insn(type); + __ppc64_runlatch_on(); + mtmsr(MSR_KERNEL); + + fini_irq_for_idle_irqsoff(); irq_set_pending_from_srr1(srr1); } @@ -347,33 +567,287 @@ void power7_idle(void) power7_idle_type(PNV_THREAD_NAP); } -static unsigned long __power9_idle_type(unsigned long stop_psscr_val, - unsigned long stop_psscr_mask) +struct p9_sprs { + /* per core */ + u64 ptcr; + u64 rpr; + u64 tscr; + u64 ldbar; + + /* per thread */ + u64 lpcr; + u64 hfscr; + u64 fscr; + u64 pid; + u64 purr; + u64 spurr; + u64 dscr; + u64 wort; + + u64 mmcra; + u32 mmcr0; + u32 mmcr1; + u64 mmcr2; + + /* per thread SPRs that get lost in shallow states */ + u64 amr; + u64 iamr; + u64 amor; + u64 uamor; +}; + +static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on) { - unsigned long psscr; + int cpu = raw_smp_processor_id(); + int first = cpu_first_thread_sibling(cpu); + unsigned long *state = &paca_ptrs[first]->idle_state; + unsigned long core_thread_mask = (1UL << threads_per_core) - 1; unsigned long srr1; + unsigned long pls; + unsigned long mmcr0 = 0; + struct p9_sprs sprs = {}; /* avoid false used-uninitialised */ + bool sprs_saved = false; - if (!prep_irq_for_idle_irqsoff()) - return 0; + if (!(psscr & (PSSCR_EC|PSSCR_ESL))) { + /* EC=ESL=0 case */ + + BUG_ON(!mmu_on); + + /* + * Wake synchronously. SRESET via xscom may still cause + * a 0x100 powersave wakeup with SRR1 reason! + */ + srr1 = isa300_idle_stop_noloss(psscr); /* go idle */ + if (likely(!srr1)) + return 0; + + /* + * Registers not saved, can't recover! + * This would be a hardware bug + */ + BUG_ON((srr1 & SRR1_WAKESTATE) != SRR1_WS_NOLOSS); + + goto out; + } + + /* EC=ESL=1 case */ +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + if (cpu_has_feature(CPU_FTR_P9_TM_XER_SO_BUG)) { + local_paca->requested_psscr = psscr; + /* order setting requested_psscr vs testing dont_stop */ + smp_mb(); + if (atomic_read(&local_paca->dont_stop)) { + local_paca->requested_psscr = 0; + return 0; + } + } +#endif + + if (!cpu_has_feature(CPU_FTR_POWER9_DD2_1)) { + /* + * POWER9 DD2 can incorrectly set PMAO when waking up + * after a state-loss idle. Saving and restoring MMCR0 + * over idle is a workaround. + */ + mmcr0 = mfspr(SPRN_MMCR0); + } + if ((psscr & PSSCR_RL_MASK) >= pnv_first_spr_loss_level) { + sprs.lpcr = mfspr(SPRN_LPCR); + sprs.hfscr = mfspr(SPRN_HFSCR); + sprs.fscr = mfspr(SPRN_FSCR); + sprs.pid = mfspr(SPRN_PID); + sprs.purr = mfspr(SPRN_PURR); + sprs.spurr = mfspr(SPRN_SPURR); + sprs.dscr = mfspr(SPRN_DSCR); + sprs.wort = mfspr(SPRN_WORT); + + sprs.mmcra = mfspr(SPRN_MMCRA); + sprs.mmcr0 = mfspr(SPRN_MMCR0); + sprs.mmcr1 = mfspr(SPRN_MMCR1); + sprs.mmcr2 = mfspr(SPRN_MMCR2); + + sprs.ptcr = mfspr(SPRN_PTCR); + sprs.rpr = mfspr(SPRN_RPR); + sprs.tscr = mfspr(SPRN_TSCR); + sprs.ldbar = mfspr(SPRN_LDBAR); + + sprs_saved = true; + + atomic_start_thread_idle(); + } + + sprs.amr = mfspr(SPRN_AMR); + sprs.iamr = mfspr(SPRN_IAMR); + sprs.amor = mfspr(SPRN_AMOR); + sprs.uamor = mfspr(SPRN_UAMOR); + + srr1 = isa300_idle_stop_mayloss(psscr); /* go idle */ + +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + local_paca->requested_psscr = 0; +#endif psscr = mfspr(SPRN_PSSCR); - psscr = (psscr & ~stop_psscr_mask) | stop_psscr_val; + WARN_ON_ONCE(!srr1); + WARN_ON_ONCE(mfmsr() & (MSR_IR|MSR_DR)); + + if ((srr1 & SRR1_WAKESTATE) != SRR1_WS_NOLOSS) { + unsigned long mmcra; + + /* + * We don't need an isync after the mtsprs here because the + * upcoming mtmsrd is execution synchronizing. + */ + mtspr(SPRN_AMR, sprs.amr); + mtspr(SPRN_IAMR, sprs.iamr); + mtspr(SPRN_AMOR, sprs.amor); + mtspr(SPRN_UAMOR, sprs.uamor); + + /* + * Workaround for POWER9 DD2.0, if we lost resources, the ERAT + * might have been corrupted and needs flushing. We also need + * to reload MMCR0 (see mmcr0 comment above). + */ + if (!cpu_has_feature(CPU_FTR_POWER9_DD2_1)) { + asm volatile(PPC_INVALIDATE_ERAT); + mtspr(SPRN_MMCR0, mmcr0); + } + + /* + * DD2.2 and earlier need to set then clear bit 60 in MMCRA + * to ensure the PMU starts running. + */ + mmcra = mfspr(SPRN_MMCRA); + mmcra |= PPC_BIT(60); + mtspr(SPRN_MMCRA, mmcra); + mmcra &= ~PPC_BIT(60); + mtspr(SPRN_MMCRA, mmcra); + } + + if (unlikely((srr1 & SRR1_WAKEMASK_P8) = SRR1_WAKEHMI)) + hmi_exception_realmode(NULL); + + /* + * On POWER9, SRR1 bits do not match exactly as expected. + * SRR1_WS_GPRLOSS (10b) can also result in SPR loss, so + * just always test PSSCR for SPR/TB state loss. + */ + pls = (psscr & PSSCR_PLS) >> PSSCR_PLS_SHIFT; + if (likely(pls < pnv_first_spr_loss_level)) { + if (sprs_saved) + atomic_stop_thread_idle(); + goto out; + } + + /* HV state loss */ + BUG_ON(!sprs_saved); + + atomic_lock_thread_idle(); + + if ((*state & core_thread_mask) != 0) + goto core_woken; + + /* Per-core SPRs */ + mtspr(SPRN_PTCR, sprs.ptcr); + mtspr(SPRN_RPR, sprs.rpr); + mtspr(SPRN_TSCR, sprs.tscr); + mtspr(SPRN_LDBAR, sprs.ldbar); + + if (pls >= pnv_first_tb_loss_level) { + /* TB loss */ + if (opal_resync_timebase() != OPAL_SUCCESS) + BUG(); + } + + /* + * isync after restoring shared SPRs and before unlocking. Unlock + * only contains hwsync which does not necessarily do the right + * thing for SPRs. + */ + isync(); + +core_woken: + atomic_unlock_and_stop_thread_idle(); + + /* Per-thread SPRs */ + mtspr(SPRN_LPCR, sprs.lpcr); + mtspr(SPRN_HFSCR, sprs.hfscr); + mtspr(SPRN_FSCR, sprs.fscr); + mtspr(SPRN_PID, sprs.pid); + mtspr(SPRN_PURR, sprs.purr); + mtspr(SPRN_SPURR, sprs.spurr); + mtspr(SPRN_DSCR, sprs.dscr); + mtspr(SPRN_WORT, sprs.wort); + + mtspr(SPRN_MMCRA, sprs.mmcra); + mtspr(SPRN_MMCR0, sprs.mmcr0); + mtspr(SPRN_MMCR1, sprs.mmcr1); + mtspr(SPRN_MMCR2, sprs.mmcr2); + + mtspr(SPRN_SPRG3, local_paca->sprg_vdso); + + if (!radix_enabled()) + __slb_restore_bolted_realmode(); + +out: + if (mmu_on) + mtmsr(MSR_KERNEL); + + return srr1; +} + +#ifdef CONFIG_HOTPLUG_CPU +static unsigned long power9_offline_stop(unsigned long psscr) +{ + unsigned long srr1; + +#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE __ppc64_runlatch_off(); - srr1 = power9_idle_stop(psscr); + srr1 = power9_idle_stop(psscr, true); __ppc64_runlatch_on(); +#else + /* + * Tell KVM we're entering idle. + * This does not have to be done in real mode because the P9 MMU + * is independent per-thread. Some steppings share radix/hash mode + * between threads, but in that case KVM has a barrier sync in real + * mode before and after switching between radix and hash. + * + * kvm_start_guest must still be called in real mode though, hence + * the false argument. + */ + local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_IDLE; - fini_irq_for_idle_irqsoff(); + __ppc64_runlatch_off(); + srr1 = power9_idle_stop(psscr, false); + __ppc64_runlatch_on(); + + mtmsr(MSR_KERNEL); +#endif return srr1; } +#endif void power9_idle_type(unsigned long stop_psscr_val, unsigned long stop_psscr_mask) { + unsigned long psscr; unsigned long srr1; - srr1 = __power9_idle_type(stop_psscr_val, stop_psscr_mask); + if (!prep_irq_for_idle_irqsoff()) + return; + + psscr = mfspr(SPRN_PSSCR); + psscr = (psscr & ~stop_psscr_mask) | stop_psscr_val; + + __ppc64_runlatch_off(); + srr1 = power9_idle_stop(psscr, true); + __ppc64_runlatch_on(); + + fini_irq_for_idle_irqsoff(); + irq_set_pending_from_srr1(srr1); } @@ -409,7 +883,7 @@ void pnv_power9_force_smt4_catch(void) atomic_inc(&paca_ptrs[cpu0+thr]->dont_stop); } /* order setting dont_stop vs testing requested_psscr */ - mb(); + smp_mb(); for (thr = 0; thr < threads_per_core; ++thr) { if (!paca_ptrs[cpu0+thr]->requested_psscr) ++awake_threads; @@ -481,7 +955,6 @@ void pnv_program_cpu_hotplug_lpcr(unsigned int cpu, u64 lpcr_val) unsigned long pnv_cpu_offline(unsigned int cpu) { unsigned long srr1; - u32 idle_states = pnv_get_supported_cpuidle_states(); __ppc64_runlatch_off(); @@ -492,15 +965,8 @@ unsigned long pnv_cpu_offline(unsigned int cpu) psscr = (psscr & ~pnv_deepest_stop_psscr_mask) | pnv_deepest_stop_psscr_val; srr1 = power9_offline_stop(psscr); - - } else if ((idle_states & OPAL_PM_WINKLE_ENABLED) && - (idle_states & OPAL_PM_LOSE_FULL_CONTEXT)) { - srr1 = power7_idle_insn(PNV_THREAD_WINKLE); - } else if ((idle_states & OPAL_PM_SLEEP_ENABLED) || - (idle_states & OPAL_PM_SLEEP_ENABLED_ER1)) { - srr1 = power7_idle_insn(PNV_THREAD_SLEEP); - } else if (idle_states & OPAL_PM_NAP_ENABLED) { - srr1 = power7_idle_insn(PNV_THREAD_NAP); + } else if (cpu_has_feature(CPU_FTR_ARCH_206) && power7_offline_type) { + srr1 = power7_offline(); } else { /* This is the fallback method. We emulate snooze */ while (!generic_check_cpu_restart(cpu)) { @@ -596,33 +1062,44 @@ int validate_psscr_val_mask(u64 *psscr_val, u64 *psscr_mask, u32 flags) * @dt_idle_states: Number of idle state entries * Returns 0 on success */ -static int __init pnv_power9_idle_init(void) +static void __init pnv_power9_idle_init(void) { u64 max_residency_ns = 0; int i; /* - * Set pnv_first_deep_stop_state, pnv_deepest_stop_psscr_{val,mask}, - * and the pnv_default_stop_{val,mask}. - * - * pnv_first_deep_stop_state should be set to the first stop - * level to cause hypervisor state loss. - * * pnv_deepest_stop_{val,mask} should be set to values corresponding to * the deepest stop state. * * pnv_default_stop_{val,mask} should be set to values corresponding to - * the shallowest (OPAL_PM_STOP_INST_FAST) loss-less stop state. + * the deepest loss-less (OPAL_PM_STOP_INST_FAST) stop state. */ - pnv_first_deep_stop_state = MAX_STOP_STATE; + pnv_first_tb_loss_level = MAX_STOP_STATE + 1; + pnv_first_spr_loss_level = MAX_STOP_STATE + 1; for (i = 0; i < nr_pnv_idle_states; i++) { int err; struct pnv_idle_states_t *state = &pnv_idle_states[i]; u64 psscr_rl = state->psscr_val & PSSCR_RL_MASK; + if ((state->flags & OPAL_PM_TIMEBASE_STOP) && + (pnv_first_tb_loss_level > psscr_rl)) + pnv_first_tb_loss_level = psscr_rl; + if ((state->flags & OPAL_PM_LOSE_FULL_CONTEXT) && - pnv_first_deep_stop_state > psscr_rl) - pnv_first_deep_stop_state = psscr_rl; + (pnv_first_spr_loss_level > psscr_rl)) + pnv_first_spr_loss_level = psscr_rl; + + /* + * The idle code does not deal with TB loss occurring + * in a shallower state than SPR loss, so force it to + * behave like SPRs are lost if TB is lost. POWER9 would + * never encouter this, but a POWER8 core would if it + * implemented the stop instruction. So this is for forward + * compatibility. + */ + if ((state->flags & OPAL_PM_TIMEBASE_STOP) && + (pnv_first_spr_loss_level > psscr_rl)) + pnv_first_spr_loss_level = psscr_rl; err = validate_psscr_val_mask(&state->psscr_val, &state->psscr_mask, @@ -647,6 +1124,7 @@ static int __init pnv_power9_idle_init(void) pnv_default_stop_val = state->psscr_val; pnv_default_stop_mask = state->psscr_mask; default_stop_found = true; + WARN_ON(state->flags & OPAL_PM_LOSE_FULL_CONTEXT); } } @@ -666,10 +1144,40 @@ static int __init pnv_power9_idle_init(void) pnv_deepest_stop_psscr_mask); } - pr_info("cpuidle-powernv: Requested Level (RL) value of first deep stop = 0x%llx\n", - pnv_first_deep_stop_state); + pr_info("cpuidle-powernv: First stop level that may lose SPRs = 0x%lld\n", + pnv_first_spr_loss_level); - return 0; + pr_info("cpuidle-powernv: First stop level that may lose timebase = 0x%lld\n", + pnv_first_tb_loss_level); +} + +static void __init pnv_disable_deep_states(void) +{ + /* + * The stop-api is unable to restore hypervisor + * resources on wakeup from platform idle states which + * lose full context. So disable such states. + */ + supported_cpuidle_states &= ~OPAL_PM_LOSE_FULL_CONTEXT; + pr_warn("cpuidle-powernv: Disabling idle states that lose full context\n"); + pr_warn("cpuidle-powernv: Idle power-savings, CPU-Hotplug affected\n"); + + if (cpu_has_feature(CPU_FTR_ARCH_300) && + (pnv_deepest_stop_flag & OPAL_PM_LOSE_FULL_CONTEXT)) { + /* + * Use the default stop state for CPU-Hotplug + * if available. + */ + if (default_stop_found) { + pnv_deepest_stop_psscr_val = pnv_default_stop_val; + pnv_deepest_stop_psscr_mask = pnv_default_stop_mask; + pr_warn("cpuidle-powernv: Offlined CPUs will stop with psscr = 0x%016llx\n", + pnv_deepest_stop_psscr_val); + } else { /* Fallback to snooze loop for CPU-Hotplug */ + deepest_stop_found = false; + pr_warn("cpuidle-powernv: Offlined CPUs will busy wait\n"); + } + } } /* @@ -684,10 +1192,8 @@ static void __init pnv_probe_idle_states(void) return; } - if (cpu_has_feature(CPU_FTR_ARCH_300)) { - if (pnv_power9_idle_init()) - return; - } + if (cpu_has_feature(CPU_FTR_ARCH_300)) + pnv_power9_idle_init(); for (i = 0; i < nr_pnv_idle_states; i++) supported_cpuidle_states |= pnv_idle_states[i].flags; @@ -807,11 +1313,33 @@ static int pnv_parse_cpuidle_dt(void) static int __init pnv_init_idle_states(void) { + int cpu; int rc = 0; - supported_cpuidle_states = 0; + + /* Set up PACA fields */ + for_each_present_cpu(cpu) { + struct paca_struct *p = paca_ptrs[cpu]; + + p->idle_state = 0; + if (cpu = cpu_first_thread_sibling(cpu)) + p->idle_state = (1 << threads_per_core) - 1; + + if (!cpu_has_feature(CPU_FTR_ARCH_300)) { + /* P7/P8 nap */ + p->thread_idle_state = PNV_THREAD_RUNNING; + } else { + /* P9 stop */ +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + p->requested_psscr = 0; + atomic_set(&p->dont_stop, 0); +#endif + } + } /* In case we error out nr_pnv_idle_states will be zero */ nr_pnv_idle_states = 0; + supported_cpuidle_states = 0; + if (cpuidle_disable != IDLE_NO_OVERRIDE) goto out; rc = pnv_parse_cpuidle_dt(); @@ -819,27 +1347,40 @@ static int __init pnv_init_idle_states(void) return rc; pnv_probe_idle_states(); - if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) { - patch_instruction( - (unsigned int *)pnv_fastsleep_workaround_at_entry, - PPC_INST_NOP); - patch_instruction( - (unsigned int *)pnv_fastsleep_workaround_at_exit, - PPC_INST_NOP); - } else { - /* - * OPAL_PM_SLEEP_ENABLED_ER1 is set. It indicates that - * workaround is needed to use fastsleep. Provide sysfs - * control to choose how this workaround has to be applied. - */ - device_create_file(cpu_subsys.dev_root, + if (!cpu_has_feature(CPU_FTR_ARCH_300)) { + if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) { + power7_fastsleep_workaround_entry = false; + power7_fastsleep_workaround_exit = false; + } else { + /* + * OPAL_PM_SLEEP_ENABLED_ER1 is set. It indicates that + * workaround is needed to use fastsleep. Provide sysfs + * control to choose how this workaround has to be + * applied. + */ + device_create_file(cpu_subsys.dev_root, &dev_attr_fastsleep_workaround_applyonce); - } + } + + update_subcore_sibling_mask(); + + if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED) { + ppc_md.power_save = power7_idle; + power7_offline_type = PNV_THREAD_NAP; + } - pnv_alloc_idle_core_states(); + if ((supported_cpuidle_states & OPAL_PM_WINKLE_ENABLED) && + (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT)) + power7_offline_type = PNV_THREAD_WINKLE; + else if ((supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED) || + (supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) + power7_offline_type = PNV_THREAD_SLEEP; + } - if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED) - ppc_md.power_save = power7_idle; + if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT) { + if (pnv_save_sprs_for_deep_states()) + pnv_disable_deep_states(); + } out: return 0; diff --git a/arch/powerpc/platforms/powernv/subcore.c b/arch/powerpc/platforms/powernv/subcore.c index 45563004feda..1d7a9fd30dd1 100644 --- a/arch/powerpc/platforms/powernv/subcore.c +++ b/arch/powerpc/platforms/powernv/subcore.c @@ -183,7 +183,7 @@ static void unsplit_core(void) cpu = smp_processor_id(); if (cpu_thread_in_core(cpu) != 0) { while (mfspr(SPRN_HID0) & mask) - power7_idle_insn(PNV_THREAD_NAP); + power7_idle_type(PNV_THREAD_NAP); per_cpu(split_state, cpu).step = SYNC_STEP_UNSPLIT; return; diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index a0f44f992360..77197110e900 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -2431,7 +2431,9 @@ static void dump_one_paca(int cpu) DUMP(p, irq_happened, "%#-*x"); DUMP(p, io_sync, "%#-*x"); DUMP(p, irq_work_pending, "%#-*x"); +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE DUMP(p, nap_state_lost, "%#-*x"); +#endif DUMP(p, sprg_vdso, "%#-*llx"); #ifdef CONFIG_PPC_TRANSACTIONAL_MEM @@ -2439,19 +2441,16 @@ static void dump_one_paca(int cpu) #endif #ifdef CONFIG_PPC_POWERNV - DUMP(p, core_idle_state_ptr, "%-*px"); - DUMP(p, thread_idle_state, "%#-*x"); - DUMP(p, thread_mask, "%#-*x"); - DUMP(p, subcore_sibling_mask, "%#-*x"); - DUMP(p, requested_psscr, "%#-*llx"); - DUMP(p, stop_sprs.pid, "%#-*llx"); - DUMP(p, stop_sprs.ldbar, "%#-*llx"); - DUMP(p, stop_sprs.fscr, "%#-*llx"); - DUMP(p, stop_sprs.hfscr, "%#-*llx"); - DUMP(p, stop_sprs.mmcr1, "%#-*llx"); - DUMP(p, stop_sprs.mmcr2, "%#-*llx"); - DUMP(p, stop_sprs.mmcra, "%#-*llx"); - DUMP(p, dont_stop.counter, "%#-*x"); + DUMP(p, idle_state, "%#-*lx"); + if (!early_cpu_has_feature(CPU_FTR_ARCH_300)) { + DUMP(p, thread_idle_state, "%#-*x"); + DUMP(p, subcore_sibling_mask, "%#-*x"); + } else { +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + DUMP(p, requested_psscr, "%#-*llx"); + DUMP(p, dont_stop.counter, "%#-*x"); +#endif + } #endif DUMP(p, accounting.utime, "%#-*lx"); -- 2.20.1 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v10 2/2] powerpc/64s: KVM update for reimplement book3s idle code in C 2019-04-28 11:45 ` Nicholas Piggin @ 2019-04-28 11:45 ` Nicholas Piggin -1 siblings, 0 replies; 10+ messages in thread From: Nicholas Piggin @ 2019-04-28 11:45 UTC (permalink / raw) To: linuxppc-dev; +Cc: Gautham R . Shenoy, kvm-ppc, Nicholas Piggin This is the KVM update to the new idle code. A few improvements: - Idle sleepers now always return to caller rather than branch out to KVM first. - This allows optimisations like very fast return to caller when no state has been lost. - KVM no longer requires nap_state_lost because it controls NVGPR save/restore itself on the way in and out. - The heavy idle wakeup KVM request check can be moved out of the normal host idle code and into the not-performance-critical offline code. - KVM nap code now returns from where it is called, which makes the flow a bit easier to follow. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/include/asm/paca.h | 1 - arch/powerpc/kernel/asm-offsets.c | 1 - arch/powerpc/kernel/exceptions-64s.S | 14 ++- arch/powerpc/kernel/idle_book3s.S | 22 ----- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 118 ++++++++++++++---------- arch/powerpc/platforms/powernv/idle.c | 15 +++ arch/powerpc/xmon/xmon.c | 3 - 7 files changed, 92 insertions(+), 82 deletions(-) diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index e55dedd7ee3e..245d11a71784 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -174,7 +174,6 @@ struct paca_struct { u8 io_sync; /* writel() needs spin_unlock sync */ u8 irq_work_pending; /* IRQ_WORK interrupt while soft-disable */ #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE - u8 nap_state_lost; /* NV GPR values lost in power7_idle */ u8 pmcregs_in_use; /* pseries puts this in lppaca */ #endif u64 sprg_vdso; /* Saved user-visible sprg */ diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index a14a77bc4243..8e02444e9d3d 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -271,7 +271,6 @@ int main(void) OFFSET(ACCOUNT_USER_TIME, paca_struct, accounting.utime); OFFSET(ACCOUNT_SYSTEM_TIME, paca_struct, accounting.stime); OFFSET(PACA_TRAP_SAVE, paca_struct, trap_save); - OFFSET(PACA_NAPSTATELOST, paca_struct, nap_state_lost); OFFSET(PACA_SPRG_VDSO, paca_struct, sprg_vdso); #else /* CONFIG_PPC64 */ #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 671c256da167..6b86055e5251 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -122,6 +122,8 @@ EXC_VIRT_NONE(0x4000, 0x100) rlwinm. r10,r10,47-31,30,31 ; \ beq- 1f ; \ cmpwi cr1,r10,2 ; \ + mfspr r3,SPRN_SRR1 ; \ + bltlr cr1 ; /* no state loss, return to idle caller */ \ BRANCH_TO_C000(r10, system_reset_idle_common) ; \ 1: \ KVMTEST_PR(n) ; \ @@ -145,12 +147,10 @@ TRAMP_KVM(PACA_EXNMI, 0x100) #ifdef CONFIG_PPC_P7_NAP EXC_COMMON_BEGIN(system_reset_idle_common) - mfspr r3,SPRN_SRR1 -#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE - /* this bltlr could be moved before the branch_to, and the - * branch_to could maybe go straight to idle_return */ - bltlr cr1 /* no state loss, return to idle caller */ -#endif + /* + * This must be a direct branch (without linker branch stub) because + * we can not use TOC at this point as r2 may not be restored yet. + */ b idle_return_gpr_loss #endif @@ -443,9 +443,7 @@ EXC_COMMON_BEGIN(machine_check_idle_common) mtlr r4 rlwinm r10,r3,47-31,30,31 cmpwi cr1,r10,2 -#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE bltlr cr1 /* no state loss, return to idle caller */ -#endif b idle_return_gpr_loss #endif /* diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index 0fb2eb731a29..2dfbd5d5b932 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -19,9 +19,6 @@ #include <asm/asm-offsets.h> #include <asm/ppc-opcode.h> #include <asm/cpuidle.h> -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE -#include <asm/kvm_book3s_asm.h> -#endif /* * Desired PSSCR in r3 @@ -93,25 +90,6 @@ _GLOBAL(isa300_idle_stop_mayloss) * a simple blr instead). */ _GLOBAL(idle_return_gpr_loss) -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE - lbz r0,HSTATE_HWTHREAD_STATE(r13) - cmpwi r0,KVM_HWTHREAD_IN_KERNEL - beq 0f - li r0,KVM_HWTHREAD_IN_KERNEL - stb r0,HSTATE_HWTHREAD_STATE(r13) - /* Order setting hwthread_state vs. testing hwthread_req */ - sync -0: lbz r0,HSTATE_HWTHREAD_REQ(r13) - cmpwi r0,0 - beq 1f - b kvm_start_guest -1: - lbz r0,PACA_NAPSTATELOST(r13) - cmpwi r0,0 - bne 2f - bltlr cr1 -2: -#endif ld r1,PACAR1(r13) ld r4,-8*19(r1) ld r5,-8*20(r1) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 58d0f1ba845d..f66191d8f841 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -35,6 +35,7 @@ #include <asm/thread_info.h> #include <asm/asm-compat.h> #include <asm/feature-fixups.h> +#include <asm/cpuidle.h> /* Sign-extend HDEC if not on POWER9 */ #define EXTEND_HDEC(reg) \ @@ -45,6 +46,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) /* Values in HSTATE_NAPPING(r13) */ #define NAPPING_CEDE 1 #define NAPPING_NOVCPU 2 +#define NAPPING_UNSPLIT 3 /* Stack frame offsets for kvmppc_hv_entry */ #define SFS 208 @@ -290,17 +292,19 @@ kvm_novcpu_exit: b kvmhv_switch_to_host /* - * We come in here when wakened from nap mode. - * Relocation is off and most register values are lost. - * r13 points to the PACA. + * We come in here when wakened from Linux offline idle code. + * Relocation is off * r3 contains the SRR1 wakeup value, SRR1 is trashed. */ - .globl kvm_start_guest -kvm_start_guest: - /* Set runlatch bit the minute you wake up from nap */ - mfspr r0, SPRN_CTRLF - ori r0, r0, 1 - mtspr SPRN_CTRLT, r0 +_GLOBAL(idle_kvm_start_guest) + ld r4,PACAEMERGSP(r13) + mfcr r5 + mflr r0 + std r1,0(r4) + std r5,8(r4) + std r0,16(r4) + subi r1,r4,STACK_FRAME_OVERHEAD + SAVE_NVGPRS(r1) /* * Could avoid this and pass it through in r3. For now, @@ -308,27 +312,23 @@ kvm_start_guest: */ mtspr SPRN_SRR1,r3 - ld r2,PACATOC(r13) - li r0,0 stb r0,PACA_FTRACE_ENABLED(r13) li r0,KVM_HWTHREAD_IN_KVM stb r0,HSTATE_HWTHREAD_STATE(r13) - /* NV GPR values from power7_idle() will no longer be valid */ - li r0,1 - stb r0,PACA_NAPSTATELOST(r13) - - /* were we napping due to cede? */ + /* kvm cede / napping does not come through here */ lbz r0,HSTATE_NAPPING(r13) - cmpwi r0,NAPPING_CEDE - beq kvm_end_cede - cmpwi r0,NAPPING_NOVCPU - beq kvm_novcpu_wakeup + twnei r0,0 + + b 1f - ld r1,PACAEMERGSP(r13) - subi r1,r1,STACK_FRAME_OVERHEAD +kvm_unsplit_wakeup: + li r0, 0 + stb r0, HSTATE_NAPPING(r13) + +1: /* * We weren't napping due to cede, so this must be a secondary @@ -437,21 +437,25 @@ kvm_no_guest: lbz r3, HSTATE_HWTHREAD_REQ(r13) cmpwi r3, 0 bne 54f -/* - * We jump to pnv_wakeup_loss, which will return to the caller - * of power7_nap in the powernv cpu offline loop. The value we - * put in r3 becomes the return value for power7_nap. pnv_wakeup_loss - * requires SRR1 in r12. - */ + + /* + * Jump to idle_return_gpr_loss, which returns to the + * idle_kvm_start_guest caller. + */ li r3, LPCR_PECE0 mfspr r4, SPRN_LPCR rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1 mtspr SPRN_LPCR, r4 - li r3, 0 - /* set up cr3 and r3 for return */ - cmpdi cr3, r3, 0 + /* set up r3 for return */ mfspr r3,SPRN_SRR1 - b idle_return_gpr_loss + REST_NVGPRS(r1) + addi r1, r1, STACK_FRAME_OVERHEAD + ld r0, 16(r1) + ld r5, 8(r1) + ld r1, 0(r1) + mtlr r0 + mtcr r5 + blr 53: HMT_LOW ld r5, HSTATE_KVM_VCORE(r13) @@ -536,6 +540,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) lbz r0, KVM_SPLIT_DO_NAP(r3) cmpwi r0, 0 beq 57f + li r3, NAPPING_UNSPLIT + stb r3, HSTATE_NAPPING(r13) li r3, (LPCR_PECEDH | LPCR_PECE0) >> 4 mfspr r5, SPRN_LPCR rlwimi r5, r3, 4, (LPCR_PECEDP | LPCR_PECEDH | LPCR_PECE0 | LPCR_PECE1) @@ -2656,6 +2662,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) lis r3, LPCR_PECEDP@h /* Do wake on privileged doorbell */ + /* Go back to host stack */ + ld r1, HSTATE_HOST_R1(r13) + /* * Take a nap until a decrementer or external or doobell interrupt * occurs, with PECE1 and PECE0 set in LPCR. @@ -2684,26 +2693,42 @@ BEGIN_FTR_SECTION * requested level = 0 (just stop dispatching) */ lis r3, (PSSCR_EC | PSSCR_ESL)@h - mtspr SPRN_PSSCR, r3 /* Set LPCR_PECE_HVEE bit to enable wakeup by HV interrupts */ li r4, LPCR_PECE_HVEE@higher sldi r4, r4, 32 or r5, r5, r4 -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) +FTR_SECTION_ELSE + li r3, PNV_THREAD_NAP +ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300) mtspr SPRN_LPCR,r5 isync - li r0, 0 - std r0, HSTATE_SCRATCH0(r13) - ptesync - ld r0, HSTATE_SCRATCH0(r13) -1: cmpd r0, r0 - bne 1b + BEGIN_FTR_SECTION - nap + bl isa300_idle_stop_mayloss FTR_SECTION_ELSE - PPC_STOP -ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300) - b . + bl isa206_idle_insn_mayloss +ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300) + + mfspr r0, SPRN_CTRLF + ori r0, r0, 1 + mtspr SPRN_CTRLT, r0 + + mtspr SPRN_SRR1, r3 + + li r0, 0 + stb r0, PACA_FTRACE_ENABLED(r13) + + li r0, KVM_HWTHREAD_IN_KVM + stb r0, HSTATE_HWTHREAD_STATE(r13) + + lbz r0, HSTATE_NAPPING(r13) + cmpwi r0, NAPPING_CEDE + beq kvm_end_cede + cmpwi r0, NAPPING_NOVCPU + beq kvm_novcpu_wakeup + cmpwi r0, NAPPING_UNSPLIT + beq kvm_unsplit_wakeup + twi 31,0,0 /* Nap state must not be zero */ 33: mr r4, r3 li r3, 0 @@ -2711,12 +2736,11 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300) b 34f kvm_end_cede: + /* Woken by external or decrementer interrupt */ + /* get vcpu pointer */ ld r4, HSTATE_KVM_VCPU(r13) - /* Woken by external or decrementer interrupt */ - ld r1, HSTATE_HOST_R1(r13) - #ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING addi r3, r4, VCPU_TB_RMINTR bl kvmhv_accumulate_time diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c index 182112fd845a..c9133f7908ca 100644 --- a/arch/powerpc/platforms/powernv/idle.c +++ b/arch/powerpc/platforms/powernv/idle.c @@ -505,6 +505,8 @@ static unsigned long power7_idle_insn(unsigned long type) return srr1; } +extern unsigned long idle_kvm_start_guest(unsigned long srr1); + #ifdef CONFIG_HOTPLUG_CPU static unsigned long power7_offline(void) { @@ -536,6 +538,14 @@ static unsigned long power7_offline(void) srr1 = power7_idle_insn(power7_offline_type); __ppc64_runlatch_on(); +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_KERNEL; + /* Order setting hwthread_state vs. testing hwthread_req */ + smp_mb(); + if (local_paca->kvm_hstate.hwthread_req) + srr1 = idle_kvm_start_guest(srr1); +#endif + mtmsr(MSR_KERNEL); return srr1; @@ -823,6 +833,11 @@ static unsigned long power9_offline_stop(unsigned long psscr) srr1 = power9_idle_stop(psscr, false); __ppc64_runlatch_on(); + local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_KERNEL; + /* Order setting hwthread_state vs. testing hwthread_req */ + smp_mb(); + if (local_paca->kvm_hstate.hwthread_req) + srr1 = idle_kvm_start_guest(srr1); mtmsr(MSR_KERNEL); #endif diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 77197110e900..e583ed3f6b93 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -2431,9 +2431,6 @@ static void dump_one_paca(int cpu) DUMP(p, irq_happened, "%#-*x"); DUMP(p, io_sync, "%#-*x"); DUMP(p, irq_work_pending, "%#-*x"); -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE - DUMP(p, nap_state_lost, "%#-*x"); -#endif DUMP(p, sprg_vdso, "%#-*llx"); #ifdef CONFIG_PPC_TRANSACTIONAL_MEM -- 2.20.1 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v10 2/2] powerpc/64s: KVM update for reimplement book3s idle code in C @ 2019-04-28 11:45 ` Nicholas Piggin 0 siblings, 0 replies; 10+ messages in thread From: Nicholas Piggin @ 2019-04-28 11:45 UTC (permalink / raw) To: linuxppc-dev; +Cc: Gautham R . Shenoy, kvm-ppc, Nicholas Piggin This is the KVM update to the new idle code. A few improvements: - Idle sleepers now always return to caller rather than branch out to KVM first. - This allows optimisations like very fast return to caller when no state has been lost. - KVM no longer requires nap_state_lost because it controls NVGPR save/restore itself on the way in and out. - The heavy idle wakeup KVM request check can be moved out of the normal host idle code and into the not-performance-critical offline code. - KVM nap code now returns from where it is called, which makes the flow a bit easier to follow. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/include/asm/paca.h | 1 - arch/powerpc/kernel/asm-offsets.c | 1 - arch/powerpc/kernel/exceptions-64s.S | 14 ++- arch/powerpc/kernel/idle_book3s.S | 22 ----- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 118 ++++++++++++++---------- arch/powerpc/platforms/powernv/idle.c | 15 +++ arch/powerpc/xmon/xmon.c | 3 - 7 files changed, 92 insertions(+), 82 deletions(-) diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index e55dedd7ee3e..245d11a71784 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -174,7 +174,6 @@ struct paca_struct { u8 io_sync; /* writel() needs spin_unlock sync */ u8 irq_work_pending; /* IRQ_WORK interrupt while soft-disable */ #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE - u8 nap_state_lost; /* NV GPR values lost in power7_idle */ u8 pmcregs_in_use; /* pseries puts this in lppaca */ #endif u64 sprg_vdso; /* Saved user-visible sprg */ diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index a14a77bc4243..8e02444e9d3d 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -271,7 +271,6 @@ int main(void) OFFSET(ACCOUNT_USER_TIME, paca_struct, accounting.utime); OFFSET(ACCOUNT_SYSTEM_TIME, paca_struct, accounting.stime); OFFSET(PACA_TRAP_SAVE, paca_struct, trap_save); - OFFSET(PACA_NAPSTATELOST, paca_struct, nap_state_lost); OFFSET(PACA_SPRG_VDSO, paca_struct, sprg_vdso); #else /* CONFIG_PPC64 */ #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 671c256da167..6b86055e5251 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -122,6 +122,8 @@ EXC_VIRT_NONE(0x4000, 0x100) rlwinm. r10,r10,47-31,30,31 ; \ beq- 1f ; \ cmpwi cr1,r10,2 ; \ + mfspr r3,SPRN_SRR1 ; \ + bltlr cr1 ; /* no state loss, return to idle caller */ \ BRANCH_TO_C000(r10, system_reset_idle_common) ; \ 1: \ KVMTEST_PR(n) ; \ @@ -145,12 +147,10 @@ TRAMP_KVM(PACA_EXNMI, 0x100) #ifdef CONFIG_PPC_P7_NAP EXC_COMMON_BEGIN(system_reset_idle_common) - mfspr r3,SPRN_SRR1 -#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE - /* this bltlr could be moved before the branch_to, and the - * branch_to could maybe go straight to idle_return */ - bltlr cr1 /* no state loss, return to idle caller */ -#endif + /* + * This must be a direct branch (without linker branch stub) because + * we can not use TOC at this point as r2 may not be restored yet. + */ b idle_return_gpr_loss #endif @@ -443,9 +443,7 @@ EXC_COMMON_BEGIN(machine_check_idle_common) mtlr r4 rlwinm r10,r3,47-31,30,31 cmpwi cr1,r10,2 -#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE bltlr cr1 /* no state loss, return to idle caller */ -#endif b idle_return_gpr_loss #endif /* diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index 0fb2eb731a29..2dfbd5d5b932 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -19,9 +19,6 @@ #include <asm/asm-offsets.h> #include <asm/ppc-opcode.h> #include <asm/cpuidle.h> -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE -#include <asm/kvm_book3s_asm.h> -#endif /* * Desired PSSCR in r3 @@ -93,25 +90,6 @@ _GLOBAL(isa300_idle_stop_mayloss) * a simple blr instead). */ _GLOBAL(idle_return_gpr_loss) -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE - lbz r0,HSTATE_HWTHREAD_STATE(r13) - cmpwi r0,KVM_HWTHREAD_IN_KERNEL - beq 0f - li r0,KVM_HWTHREAD_IN_KERNEL - stb r0,HSTATE_HWTHREAD_STATE(r13) - /* Order setting hwthread_state vs. testing hwthread_req */ - sync -0: lbz r0,HSTATE_HWTHREAD_REQ(r13) - cmpwi r0,0 - beq 1f - b kvm_start_guest -1: - lbz r0,PACA_NAPSTATELOST(r13) - cmpwi r0,0 - bne 2f - bltlr cr1 -2: -#endif ld r1,PACAR1(r13) ld r4,-8*19(r1) ld r5,-8*20(r1) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 58d0f1ba845d..f66191d8f841 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -35,6 +35,7 @@ #include <asm/thread_info.h> #include <asm/asm-compat.h> #include <asm/feature-fixups.h> +#include <asm/cpuidle.h> /* Sign-extend HDEC if not on POWER9 */ #define EXTEND_HDEC(reg) \ @@ -45,6 +46,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) /* Values in HSTATE_NAPPING(r13) */ #define NAPPING_CEDE 1 #define NAPPING_NOVCPU 2 +#define NAPPING_UNSPLIT 3 /* Stack frame offsets for kvmppc_hv_entry */ #define SFS 208 @@ -290,17 +292,19 @@ kvm_novcpu_exit: b kvmhv_switch_to_host /* - * We come in here when wakened from nap mode. - * Relocation is off and most register values are lost. - * r13 points to the PACA. + * We come in here when wakened from Linux offline idle code. + * Relocation is off * r3 contains the SRR1 wakeup value, SRR1 is trashed. */ - .globl kvm_start_guest -kvm_start_guest: - /* Set runlatch bit the minute you wake up from nap */ - mfspr r0, SPRN_CTRLF - ori r0, r0, 1 - mtspr SPRN_CTRLT, r0 +_GLOBAL(idle_kvm_start_guest) + ld r4,PACAEMERGSP(r13) + mfcr r5 + mflr r0 + std r1,0(r4) + std r5,8(r4) + std r0,16(r4) + subi r1,r4,STACK_FRAME_OVERHEAD + SAVE_NVGPRS(r1) /* * Could avoid this and pass it through in r3. For now, @@ -308,27 +312,23 @@ kvm_start_guest: */ mtspr SPRN_SRR1,r3 - ld r2,PACATOC(r13) - li r0,0 stb r0,PACA_FTRACE_ENABLED(r13) li r0,KVM_HWTHREAD_IN_KVM stb r0,HSTATE_HWTHREAD_STATE(r13) - /* NV GPR values from power7_idle() will no longer be valid */ - li r0,1 - stb r0,PACA_NAPSTATELOST(r13) - - /* were we napping due to cede? */ + /* kvm cede / napping does not come through here */ lbz r0,HSTATE_NAPPING(r13) - cmpwi r0,NAPPING_CEDE - beq kvm_end_cede - cmpwi r0,NAPPING_NOVCPU - beq kvm_novcpu_wakeup + twnei r0,0 + + b 1f - ld r1,PACAEMERGSP(r13) - subi r1,r1,STACK_FRAME_OVERHEAD +kvm_unsplit_wakeup: + li r0, 0 + stb r0, HSTATE_NAPPING(r13) + +1: /* * We weren't napping due to cede, so this must be a secondary @@ -437,21 +437,25 @@ kvm_no_guest: lbz r3, HSTATE_HWTHREAD_REQ(r13) cmpwi r3, 0 bne 54f -/* - * We jump to pnv_wakeup_loss, which will return to the caller - * of power7_nap in the powernv cpu offline loop. The value we - * put in r3 becomes the return value for power7_nap. pnv_wakeup_loss - * requires SRR1 in r12. - */ + + /* + * Jump to idle_return_gpr_loss, which returns to the + * idle_kvm_start_guest caller. + */ li r3, LPCR_PECE0 mfspr r4, SPRN_LPCR rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1 mtspr SPRN_LPCR, r4 - li r3, 0 - /* set up cr3 and r3 for return */ - cmpdi cr3, r3, 0 + /* set up r3 for return */ mfspr r3,SPRN_SRR1 - b idle_return_gpr_loss + REST_NVGPRS(r1) + addi r1, r1, STACK_FRAME_OVERHEAD + ld r0, 16(r1) + ld r5, 8(r1) + ld r1, 0(r1) + mtlr r0 + mtcr r5 + blr 53: HMT_LOW ld r5, HSTATE_KVM_VCORE(r13) @@ -536,6 +540,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) lbz r0, KVM_SPLIT_DO_NAP(r3) cmpwi r0, 0 beq 57f + li r3, NAPPING_UNSPLIT + stb r3, HSTATE_NAPPING(r13) li r3, (LPCR_PECEDH | LPCR_PECE0) >> 4 mfspr r5, SPRN_LPCR rlwimi r5, r3, 4, (LPCR_PECEDP | LPCR_PECEDH | LPCR_PECE0 | LPCR_PECE1) @@ -2656,6 +2662,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) lis r3, LPCR_PECEDP@h /* Do wake on privileged doorbell */ + /* Go back to host stack */ + ld r1, HSTATE_HOST_R1(r13) + /* * Take a nap until a decrementer or external or doobell interrupt * occurs, with PECE1 and PECE0 set in LPCR. @@ -2684,26 +2693,42 @@ BEGIN_FTR_SECTION * requested level = 0 (just stop dispatching) */ lis r3, (PSSCR_EC | PSSCR_ESL)@h - mtspr SPRN_PSSCR, r3 /* Set LPCR_PECE_HVEE bit to enable wakeup by HV interrupts */ li r4, LPCR_PECE_HVEE@higher sldi r4, r4, 32 or r5, r5, r4 -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) +FTR_SECTION_ELSE + li r3, PNV_THREAD_NAP +ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300) mtspr SPRN_LPCR,r5 isync - li r0, 0 - std r0, HSTATE_SCRATCH0(r13) - ptesync - ld r0, HSTATE_SCRATCH0(r13) -1: cmpd r0, r0 - bne 1b + BEGIN_FTR_SECTION - nap + bl isa300_idle_stop_mayloss FTR_SECTION_ELSE - PPC_STOP -ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300) - b . + bl isa206_idle_insn_mayloss +ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300) + + mfspr r0, SPRN_CTRLF + ori r0, r0, 1 + mtspr SPRN_CTRLT, r0 + + mtspr SPRN_SRR1, r3 + + li r0, 0 + stb r0, PACA_FTRACE_ENABLED(r13) + + li r0, KVM_HWTHREAD_IN_KVM + stb r0, HSTATE_HWTHREAD_STATE(r13) + + lbz r0, HSTATE_NAPPING(r13) + cmpwi r0, NAPPING_CEDE + beq kvm_end_cede + cmpwi r0, NAPPING_NOVCPU + beq kvm_novcpu_wakeup + cmpwi r0, NAPPING_UNSPLIT + beq kvm_unsplit_wakeup + twi 31,0,0 /* Nap state must not be zero */ 33: mr r4, r3 li r3, 0 @@ -2711,12 +2736,11 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300) b 34f kvm_end_cede: + /* Woken by external or decrementer interrupt */ + /* get vcpu pointer */ ld r4, HSTATE_KVM_VCPU(r13) - /* Woken by external or decrementer interrupt */ - ld r1, HSTATE_HOST_R1(r13) - #ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING addi r3, r4, VCPU_TB_RMINTR bl kvmhv_accumulate_time diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c index 182112fd845a..c9133f7908ca 100644 --- a/arch/powerpc/platforms/powernv/idle.c +++ b/arch/powerpc/platforms/powernv/idle.c @@ -505,6 +505,8 @@ static unsigned long power7_idle_insn(unsigned long type) return srr1; } +extern unsigned long idle_kvm_start_guest(unsigned long srr1); + #ifdef CONFIG_HOTPLUG_CPU static unsigned long power7_offline(void) { @@ -536,6 +538,14 @@ static unsigned long power7_offline(void) srr1 = power7_idle_insn(power7_offline_type); __ppc64_runlatch_on(); +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_KERNEL; + /* Order setting hwthread_state vs. testing hwthread_req */ + smp_mb(); + if (local_paca->kvm_hstate.hwthread_req) + srr1 = idle_kvm_start_guest(srr1); +#endif + mtmsr(MSR_KERNEL); return srr1; @@ -823,6 +833,11 @@ static unsigned long power9_offline_stop(unsigned long psscr) srr1 = power9_idle_stop(psscr, false); __ppc64_runlatch_on(); + local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_KERNEL; + /* Order setting hwthread_state vs. testing hwthread_req */ + smp_mb(); + if (local_paca->kvm_hstate.hwthread_req) + srr1 = idle_kvm_start_guest(srr1); mtmsr(MSR_KERNEL); #endif diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 77197110e900..e583ed3f6b93 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -2431,9 +2431,6 @@ static void dump_one_paca(int cpu) DUMP(p, irq_happened, "%#-*x"); DUMP(p, io_sync, "%#-*x"); DUMP(p, irq_work_pending, "%#-*x"); -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE - DUMP(p, nap_state_lost, "%#-*x"); -#endif DUMP(p, sprg_vdso, "%#-*llx"); #ifdef CONFIG_PPC_TRANSACTIONAL_MEM -- 2.20.1 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v10 2/2] powerpc/64s: KVM update for reimplement book3s idle code in C 2019-04-28 11:45 ` Nicholas Piggin @ 2019-05-13 6:42 ` Paul Mackerras -1 siblings, 0 replies; 10+ messages in thread From: Paul Mackerras @ 2019-05-13 6:42 UTC (permalink / raw) To: Nicholas Piggin; +Cc: Gautham R . Shenoy, linuxppc-dev, kvm-ppc On Sun, Apr 28, 2019 at 09:45:15PM +1000, Nicholas Piggin wrote: > This is the KVM update to the new idle code. A few improvements: > > - Idle sleepers now always return to caller rather than branch out > to KVM first. > - This allows optimisations like very fast return to caller when no > state has been lost. > - KVM no longer requires nap_state_lost because it controls NVGPR > save/restore itself on the way in and out. > - The heavy idle wakeup KVM request check can be moved out of the > normal host idle code and into the not-performance-critical offline > code. > - KVM nap code now returns from where it is called, which makes the > flow a bit easier to follow. One question below... > diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S > index 58d0f1ba845d..f66191d8f841 100644 > --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S > +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S ... > @@ -2656,6 +2662,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) > > lis r3, LPCR_PECEDP@h /* Do wake on privileged doorbell */ > > + /* Go back to host stack */ > + ld r1, HSTATE_HOST_R1(r13) At this point we are in kvmppc_h_cede, which we branched to from hcall_try_real_mode, which came from the guest exit path, where we have already loaded r1 from HSTATE_HOST_R1(r13). So if there is a path to get here with r1 not already set to HSTATE_HOST_R1(r13), then I missed it - please point it out to me. Otherwise this statement seems superfluous. Paul. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v10 2/2] powerpc/64s: KVM update for reimplement book3s idle code in C @ 2019-05-13 6:42 ` Paul Mackerras 0 siblings, 0 replies; 10+ messages in thread From: Paul Mackerras @ 2019-05-13 6:42 UTC (permalink / raw) To: Nicholas Piggin; +Cc: Gautham R . Shenoy, linuxppc-dev, kvm-ppc On Sun, Apr 28, 2019 at 09:45:15PM +1000, Nicholas Piggin wrote: > This is the KVM update to the new idle code. A few improvements: > > - Idle sleepers now always return to caller rather than branch out > to KVM first. > - This allows optimisations like very fast return to caller when no > state has been lost. > - KVM no longer requires nap_state_lost because it controls NVGPR > save/restore itself on the way in and out. > - The heavy idle wakeup KVM request check can be moved out of the > normal host idle code and into the not-performance-critical offline > code. > - KVM nap code now returns from where it is called, which makes the > flow a bit easier to follow. One question below... > diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S > index 58d0f1ba845d..f66191d8f841 100644 > --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S > +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S ... > @@ -2656,6 +2662,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) > > lis r3, LPCR_PECEDP@h /* Do wake on privileged doorbell */ > > + /* Go back to host stack */ > + ld r1, HSTATE_HOST_R1(r13) At this point we are in kvmppc_h_cede, which we branched to from hcall_try_real_mode, which came from the guest exit path, where we have already loaded r1 from HSTATE_HOST_R1(r13). So if there is a path to get here with r1 not already set to HSTATE_HOST_R1(r13), then I missed it - please point it out to me. Otherwise this statement seems superfluous. Paul. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v10 2/2] powerpc/64s: KVM update for reimplement book3s idle code in C 2019-05-13 6:42 ` Paul Mackerras @ 2019-05-16 4:43 ` Nicholas Piggin -1 siblings, 0 replies; 10+ messages in thread From: Nicholas Piggin @ 2019-05-16 4:43 UTC (permalink / raw) To: Paul Mackerras; +Cc: Gautham R . Shenoy, linuxppc-dev, kvm-ppc Paul Mackerras's on May 13, 2019 4:42 pm: > On Sun, Apr 28, 2019 at 09:45:15PM +1000, Nicholas Piggin wrote: >> This is the KVM update to the new idle code. A few improvements: >> >> - Idle sleepers now always return to caller rather than branch out >> to KVM first. >> - This allows optimisations like very fast return to caller when no >> state has been lost. >> - KVM no longer requires nap_state_lost because it controls NVGPR >> save/restore itself on the way in and out. >> - The heavy idle wakeup KVM request check can be moved out of the >> normal host idle code and into the not-performance-critical offline >> code. >> - KVM nap code now returns from where it is called, which makes the >> flow a bit easier to follow. > > One question below... > >> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S >> index 58d0f1ba845d..f66191d8f841 100644 >> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S >> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S > ... >> @@ -2656,6 +2662,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) >> >> lis r3, LPCR_PECEDP@h /* Do wake on privileged doorbell */ >> >> + /* Go back to host stack */ >> + ld r1, HSTATE_HOST_R1(r13) > > At this point we are in kvmppc_h_cede, which we branched to from > hcall_try_real_mode, which came from the guest exit path, where we > have already loaded r1 from HSTATE_HOST_R1(r13). So if there is a > path to get here with r1 not already set to HSTATE_HOST_R1(r13), then > I missed it - please point it out to me. Otherwise this statement > seems superfluous. I'm not sure why I put that there. I think you're right it could be removed. Thanks, Nick ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v10 2/2] powerpc/64s: KVM update for reimplement book3s idle code in C @ 2019-05-16 4:43 ` Nicholas Piggin 0 siblings, 0 replies; 10+ messages in thread From: Nicholas Piggin @ 2019-05-16 4:43 UTC (permalink / raw) To: Paul Mackerras; +Cc: Gautham R . Shenoy, linuxppc-dev, kvm-ppc Paul Mackerras's on May 13, 2019 4:42 pm: > On Sun, Apr 28, 2019 at 09:45:15PM +1000, Nicholas Piggin wrote: >> This is the KVM update to the new idle code. A few improvements: >> >> - Idle sleepers now always return to caller rather than branch out >> to KVM first. >> - This allows optimisations like very fast return to caller when no >> state has been lost. >> - KVM no longer requires nap_state_lost because it controls NVGPR >> save/restore itself on the way in and out. >> - The heavy idle wakeup KVM request check can be moved out of the >> normal host idle code and into the not-performance-critical offline >> code. >> - KVM nap code now returns from where it is called, which makes the >> flow a bit easier to follow. > > One question below... > >> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S >> index 58d0f1ba845d..f66191d8f841 100644 >> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S >> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S > ... >> @@ -2656,6 +2662,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) >> >> lis r3, LPCR_PECEDP@h /* Do wake on privileged doorbell */ >> >> + /* Go back to host stack */ >> + ld r1, HSTATE_HOST_R1(r13) > > At this point we are in kvmppc_h_cede, which we branched to from > hcall_try_real_mode, which came from the guest exit path, where we > have already loaded r1 from HSTATE_HOST_R1(r13). So if there is a > path to get here with r1 not already set to HSTATE_HOST_R1(r13), then > I missed it - please point it out to me. Otherwise this statement > seems superfluous. I'm not sure why I put that there. I think you're right it could be removed. Thanks, Nick ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2019-05-16 4:45 UTC | newest] Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-04-28 11:45 [PATCH v10 0/2] powerpc/64s: reimplement book3s idle code in C Nicholas Piggin 2019-04-28 11:45 ` Nicholas Piggin 2019-04-28 11:45 ` [PATCH v10 1/2] " Nicholas Piggin 2019-04-28 11:45 ` Nicholas Piggin 2019-04-28 11:45 ` [PATCH v10 2/2] powerpc/64s: KVM update for " Nicholas Piggin 2019-04-28 11:45 ` Nicholas Piggin 2019-05-13 6:42 ` Paul Mackerras 2019-05-13 6:42 ` Paul Mackerras 2019-05-16 4:43 ` Nicholas Piggin 2019-05-16 4:43 ` Nicholas Piggin
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