--- /dev/null
+/*
+ * This file contains the power_save function for Power7 CPUs.
+ *
+ * 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.
+ */
+
+#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/mmu-hash64.h>
+
+#undef DEBUG
+
+/*
+ * Use unused space in the interrupt stack to save and restore
+ * registers for winkle support.
+ */
+#define _SDR1 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
+
+/* Idle state entry routines */
+
+#define IDLE_STATE_ENTER_SEQ(IDLE_INST) \
+ /* Magic NAP/SLEEP/WINKLE mode enter sequence */ \
+ std r0,0(r1); \
+ ptesync; \
+ ld r0,0(r1); \
+1: cmp cr0,r0,r0; \
+ bne 1b; \
+ IDLE_INST; \
+ b .
+
+ .text
+
+/*
+ * Pass requested state in r3:
+ * r3 - PNV_THREAD_NAP/SLEEP/WINKLE
+ *
+ * To check IRQ_HAPPENED in r4
+ * 0 - don't check
+ * 1 - check
+ */
+_GLOBAL(power7_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.
+ */
+ mflr r0
+ std r0,16(r1)
+ stdu r1,-INT_FRAME_SIZE(r1)
+ std r0,_LINK(r1)
+ std r0,_NIP(r1)
+
+#ifndef CONFIG_SMP
+ /* Make sure FPU, VSX etc... are flushed as we may lose
+ * state when going to nap mode
+ */
+ bl discard_lazy_cpu_state
+#endif /* CONFIG_SMP */
+
+ /* Hard disable interrupts */
+ mfmsr r9
+ rldicl r9,r9,48,1
+ rotldi r9,r9,16
+ mtmsrd r9,1 /* hard-disable interrupts */
+
+ /* Check if something happened while soft-disabled */
+ lbz r0,PACAIRQHAPPENED(r13)
+ andi. r0,r0,~PACA_IRQ_HARD_DIS@l
+ beq 1f
+ cmpwi cr0,r4,0
+ beq 1f
+ addi r1,r1,INT_FRAME_SIZE
+ ld r0,16(r1)
+ li r3,0 /* Return 0 (no nap) */
+ mtlr r0
+ blr
+
+1: /* We mark irqs hard disabled as this is the state we'll
+ * be in when returning and we need to tell arch_local_irq_restore()
+ * about it
+ */
+ li r0,PACA_IRQ_HARD_DIS
+ stb r0,PACAIRQHAPPENED(r13)
+
+ /* We haven't lost state ... yet */
+ li r0,0
+ stb r0,PACA_NAPSTATELOST(r13)
+
+ /* Continue saving state */
+ SAVE_GPR(2, r1)
+ SAVE_NVGPRS(r1)
+ mfcr r4
+ std r4,_CCR(r1)
+ std r9,_MSR(r1)
+ std r1,PACAR1(r13)
+
+ /*
+ * 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(r5, MSR_IDLE)
+ li r6, MSR_RI
+ andc r6, r9, r6
+ LOAD_REG_ADDR(r7, power7_enter_nap_mode)
+ mtmsrd r6, 1 /* clear RI before setting SRR0/1 */
+ mtspr SPRN_SRR0, r7
+ mtspr SPRN_SRR1, r5
+ rfid
+
+ .globl power7_enter_nap_mode
+power7_enter_nap_mode:
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+ /* Tell KVM we're napping */
+ li r4,KVM_HWTHREAD_IN_NAP
+ 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(PPC_NAP)
+ /* No return */
+2:
+ /* Sleep or winkle */
+ lbz r7,PACA_THREAD_MASK(r13)
+ ld r14,PACA_CORE_IDLE_STATE_PTR(r13)
+lwarx_loop1:
+ lwarx r15,0,r14
+ andc r15,r15,r7 /* Clear thread bit */
+
+ andi. r15,r15,PNV_CORE_IDLE_THREAD_BITS
+
+/*
+ * If cr0 = 0, then current thread is the last thread of the core entering
+ * sleep. Last thread needs to execute the hardware bug workaround code if
+ * required by the platform.
+ * Make the workaround call unconditionally here. The below branch call is
+ * patched out when the idle states are discovered if the platform does not
+ * require it.
+ */
+.global pnv_fastsleep_workaround_at_entry
+pnv_fastsleep_workaround_at_entry:
+ beq fastsleep_workaround_at_entry
+
+ stwcx. r15,0,r14
+ bne- lwarx_loop1
+ isync
+
+common_enter: /* common code for all the threads entering sleep or winkle */
+ bgt cr3,enter_winkle
+ IDLE_STATE_ENTER_SEQ(PPC_SLEEP)
+
+fastsleep_workaround_at_entry:
+ ori r15,r15,PNV_CORE_IDLE_LOCK_BIT
+ stwcx. r15,0,r14
+ bne- lwarx_loop1
+ isync
+
+ /* Fast sleep workaround */
+ li r3,1
+ li r4,1
+ li r0,OPAL_CONFIG_CPU_IDLE_STATE
+ bl opal_call_realmode
+
+ /* Clear Lock bit */
+ li r0,0
+ lwsync
+ stw r0,0(r14)
+ b common_enter
+
+enter_winkle:
+ /*
+ * 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
+ */
+ mfspr r3,SPRN_SDR1
+ std r3,_SDR1(r1)
+ 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)
+ IDLE_STATE_ENTER_SEQ(PPC_WINKLE)
+
+_GLOBAL(power7_idle)
+ /* Now check if user or arch enabled NAP mode */
+ LOAD_REG_ADDRBASE(r3,powersave_nap)
+ lwz r4,ADDROFF(powersave_nap)(r3)
+ cmpwi 0,r4,0
+ beqlr
+ li r3, 1
+ /* fall through */
+
+_GLOBAL(power7_nap)
+ mr r4,r3
+ li r3,PNV_THREAD_NAP
+ b power7_powersave_common
+ /* No return */
+
+_GLOBAL(power7_sleep)
+ li r3,PNV_THREAD_SLEEP
+ li r4,1
+ b power7_powersave_common
+ /* No return */
+
+_GLOBAL(power7_winkle)
+ li r3,3
+ li r4,1
+ b power7_powersave_common
+ /* No return */
+
+#define CHECK_HMI_INTERRUPT \
+ mfspr r0,SPRN_SRR1; \
+BEGIN_FTR_SECTION_NESTED(66); \
+ rlwinm r0,r0,45-31,0xf; /* extract wake reason field (P8) */ \
+FTR_SECTION_ELSE_NESTED(66); \
+ rlwinm r0,r0,45-31,0xe; /* 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 r0,OPAL_HANDLE_HMI; /* Pass opal token argument*/ \
+ bl opal_call_realmode; \
+ ld r3,ORIG_GPR3(r1); /* Restore original r3 */ \
+20: nop;
+
+
+_GLOBAL(power7_wakeup_tb_loss)
+ ld r2,PACATOC(r13);
+ ld r1,PACAR1(r13)
+ /*
+ * Before entering any idle state, the NVGPRs are saved in the stack
+ * and they are restored before switching to the process context. Hence
+ * until they are restored, they are free to be used.
+ *
+ * Save SRR1 in a NVGPR as it might be clobbered in opal_call_realmode
+ * (called in CHECK_HMI_INTERRUPT). SRR1 is required to determine the
+ * wakeup reason if we branch to kvm_start_guest.
+ */
+
+ mfspr r16,SPRN_SRR1
+BEGIN_FTR_SECTION
+ CHECK_HMI_INTERRUPT
+END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
+
+ lbz r7,PACA_THREAD_MASK(r13)
+ ld r14,PACA_CORE_IDLE_STATE_PTR(r13)
+lwarx_loop2:
+ lwarx r15,0,r14
+ andi. r9,r15,PNV_CORE_IDLE_LOCK_BIT
+ /*
+ * Lock bit is set in one of the 2 cases-
+ * a. In the sleep/winkle enter path, the last thread is executing
+ * fastsleep workaround code.
+ * b. In the wake up path, another thread is executing fastsleep
+ * workaround undo code or resyncing timebase or restoring context
+ * In either case loop until the lock bit is cleared.
+ */
+ bne core_idle_lock_held
+
+ cmpwi cr2,r15,0
+ lbz r4,PACA_SUBCORE_SIBLING_MASK(r13)
+ and r4,r4,r15
+ cmpwi cr1,r4,0 /* Check if first in subcore */
+
+ /*
+ * At this stage
+ * cr1 - 0b0100 if first thread to wakeup in subcore
+ * cr2 - 0b0100 if first thread to wakeup in core
+ * cr3- 0b0010 if waking up from sleep or winkle
+ * cr4 - 0b0100 if waking up from winkle
+ */
+
+ or r15,r15,r7 /* Set thread bit */
+
+ beq cr1,first_thread_in_subcore
+
+ /* Not first thread in subcore to wake up */
+ stwcx. r15,0,r14
+ bne- lwarx_loop2
+ isync
+ b common_exit
+
+core_idle_lock_held:
+ HMT_LOW
+core_idle_lock_loop:
+ lwz r15,0(14)
+ andi. r9,r15,PNV_CORE_IDLE_LOCK_BIT
+ bne core_idle_lock_loop
+ HMT_MEDIUM
+ b lwarx_loop2
+
+first_thread_in_subcore:
+ /* First thread in subcore to wakeup */
+ ori r15,r15,PNV_CORE_IDLE_LOCK_BIT
+ stwcx. r15,0,r14
+ bne- lwarx_loop2
+ isync
+
+ /*
+ * If waking up from sleep, subcore state is not lost. Hence
+ * skip subcore state restore
+ */
+ bne 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 fastsleep. It needs to
+ * call the fastsleep workaround code if the platform requires it.
+ * Call it unconditionally here. The below branch instruction will
+ * be patched out when the idle states are discovered if platform
+ * does not require workaround.
+ */
+.global pnv_fastsleep_workaround_at_exit
+pnv_fastsleep_workaround_at_exit:
+ b fastsleep_workaround_at_exit
+
+timebase_resync:
+ /* Do timebase resync if we are waking up from sleep. Use cr3 value
+ * set in exceptions-64s.S */
+ ble cr3,clear_lock
+ /* Time base re-sync */
+ li r0,OPAL_RESYNC_TIMEBASE
+ bl opal_call_realmode;
+ /* TODO: Check r3 for failure */
+
+ /*
+ * If waking up from sleep, per core state is not lost, skip to
+ * clear_lock.
+ */
+ bne cr4,clear_lock
+
+ /* Restore per core state */
+ ld r4,_TSCR(r1)
+ mtspr SPRN_TSCR,r4
+ ld r4,_WORC(r1)
+ mtspr SPRN_WORC,r4
+
+clear_lock:
+ andi. r15,r15,PNV_CORE_IDLE_THREAD_BITS
+ 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.
+ */
+ bne cr4,hypervisor_state_restored
+
+ /* Waking up from winkle */
+
+ /* Restore per thread state */
+ bl __restore_cpu_power8
+
+ /* 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
+
+ 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
+
+hypervisor_state_restored:
+
+ li r5,PNV_THREAD_RUNNING
+ stb r5,PACA_THREAD_IDLE_STATE(r13)
+
+ mtspr SPRN_SRR1,r16
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+ li r0,KVM_HWTHREAD_IN_KERNEL
+ stb r0,HSTATE_HWTHREAD_STATE(r13)
+ /* Order setting hwthread_state vs. testing hwthread_req */
+ sync
+ lbz r0,HSTATE_HWTHREAD_REQ(r13)
+ cmpwi r0,0
+ beq 6f
+ b kvm_start_guest
+6:
+#endif
+
+ REST_NVGPRS(r1)
+ REST_GPR(2, r1)
+ ld r3,_CCR(r1)
+ ld r4,_MSR(r1)
+ ld r5,_NIP(r1)
+ addi r1,r1,INT_FRAME_SIZE
+ mtcr r3
+ mfspr r3,SPRN_SRR1 /* Return SRR1 */
+ mtspr SPRN_SRR1,r4
+ mtspr SPRN_SRR0,r5
+ rfid
+
+fastsleep_workaround_at_exit:
+ li r3,1
+ li r4,0
+ li r0,OPAL_CONFIG_CPU_IDLE_STATE
+ bl opal_call_realmode
+ b timebase_resync
+
+/*
+ * R3 here contains the value that will be returned to the caller
+ * of power7_nap.
+ */
+_GLOBAL(power7_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)
+ ld r6,_CCR(r1)
+ ld r4,_MSR(r1)
+ ld r5,_NIP(r1)
+ addi r1,r1,INT_FRAME_SIZE
+ mtcr r6
+ mtspr SPRN_SRR1,r4
+ mtspr SPRN_SRR0,r5
+ rfid
+
+/*
+ * R3 here contains the value that will be returned to the caller
+ * of power7_nap.
+ */
+_GLOBAL(power7_wakeup_noloss)
+ lbz r0,PACA_NAPSTATELOST(r13)
+ cmpwi r0,0
+ bne power7_wakeup_loss
+BEGIN_FTR_SECTION
+ CHECK_HMI_INTERRUPT
+END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
+ ld r1,PACAR1(r13)
+ ld r6,_CCR(r1)
+ ld r4,_MSR(r1)
+ ld r5,_NIP(r1)
+ addi r1,r1,INT_FRAME_SIZE
+ mtcr r6
+ mtspr SPRN_SRR1,r4
+ mtspr SPRN_SRR0,r5
+ rfid
Code Review / kvmfornfv.git / blobdiff