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 <e...@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npig...@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

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