arch/powerpc/kernel/idle_power7.S

   1 /*
   2  *  This file contains the power_save function for Power7 CPUs.
   3  *
   4  *  This program is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU General Public License
   6  *  as published by the Free Software Foundation; either version
   7  *  2 of the License, or (at your option) any later version.
   8  */
   9
  10 #include <linux/threads.h>
  11 #include <asm/processor.h>
  12 #include <asm/page.h>
  13 #include <asm/cputable.h>
  14 #include <asm/thread_info.h>
  15 #include <asm/ppc_asm.h>
  16 #include <asm/asm-offsets.h>
  17 #include <asm/ppc-opcode.h>
  18 #include <asm/hw_irq.h>
  19 #include <asm/kvm_book3s_asm.h>
  20 #include <asm/opal.h>
  21
  22 #undef DEBUG
  23
  24 /* Idle state entry routines */
  25
  26 #define IDLE_STATE_ENTER_SEQ(IDLE_INST)                         \
  27         /* Magic NAP/SLEEP/WINKLE mode enter sequence */        \
  28         std     r0,0(r1);                                       \
  29         ptesync;                                                \
  30         ld      r0,0(r1);                                       \
  31 1:      cmp     cr0,r0,r0;                                      \
  32         bne     1b;                                             \
  33         IDLE_INST;                                              \
  34         b       .
  35
  36         .text
  37
  38 /*
  39  * Pass requested state in r3:
  40  *      0 - nap
  41  *      1 - sleep
  42  *
  43  * To check IRQ_HAPPENED in r4
  44  *      0 - don't check
  45  *      1 - check
  46  */
  47 _GLOBAL(power7_powersave_common)
  48         /* Use r3 to pass state nap/sleep/winkle */
  49         /* NAP is a state loss, we create a regs frame on the
  50          * stack, fill it up with the state we care about and
  51          * stick a pointer to it in PACAR1. We really only
  52          * need to save PC, some CR bits and the NV GPRs,
  53          * but for now an interrupt frame will do.
  54          */
  55         mflr    r0
  56         std     r0,16(r1)
  57         stdu    r1,-INT_FRAME_SIZE(r1)
  58         std     r0,_LINK(r1)
  59         std     r0,_NIP(r1)
  60
  61 #ifndef CONFIG_SMP
  62         /* Make sure FPU, VSX etc... are flushed as we may lose
  63          * state when going to nap mode
  64          */
  65         bl      discard_lazy_cpu_state
  66 #endif /* CONFIG_SMP */
  67
  68         /* Hard disable interrupts */
  69         mfmsr   r9
  70         rldicl  r9,r9,48,1
  71         rotldi  r9,r9,16
  72         mtmsrd  r9,1                    /* hard-disable interrupts */
  73
  74         /* Check if something happened while soft-disabled */
  75         lbz     r0,PACAIRQHAPPENED(r13)
  76         andi.   r0,r0,~PACA_IRQ_HARD_DIS@l
  77         beq     1f
  78         cmpwi   cr0,r4,0
  79         beq     1f
  80         addi    r1,r1,INT_FRAME_SIZE
  81         ld      r0,16(r1)
  82         mtlr    r0
  83         blr
  84
  85 1:      /* We mark irqs hard disabled as this is the state we'll
  86          * be in when returning and we need to tell arch_local_irq_restore()
  87          * about it
  88          */
  89         li      r0,PACA_IRQ_HARD_DIS
  90         stb     r0,PACAIRQHAPPENED(r13)
  91
  92         /* We haven't lost state ... yet */
  93         li      r0,0
  94         stb     r0,PACA_NAPSTATELOST(r13)
  95
  96         /* Continue saving state */
  97         SAVE_GPR(2, r1)
  98         SAVE_NVGPRS(r1)
  99         mfcr    r4
 100         std     r4,_CCR(r1)
 101         std     r9,_MSR(r1)
 102         std     r1,PACAR1(r13)
 103
 104 _GLOBAL(power7_enter_nap_mode)
 105 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 106         /* Tell KVM we're napping */
 107         li      r4,KVM_HWTHREAD_IN_NAP
 108         stb     r4,HSTATE_HWTHREAD_STATE(r13)
 109 #endif
 110         cmpwi   cr0,r3,1
 111         beq     2f
 112         IDLE_STATE_ENTER_SEQ(PPC_NAP)
 113         /* No return */
 114 2:      IDLE_STATE_ENTER_SEQ(PPC_SLEEP)
 115         /* No return */
 116
 117 _GLOBAL(power7_idle)
 118         /* Now check if user or arch enabled NAP mode */
 119         LOAD_REG_ADDRBASE(r3,powersave_nap)
 120         lwz     r4,ADDROFF(powersave_nap)(r3)
 121         cmpwi   0,r4,0
 122         beqlr
 123         li      r3, 1
 124         /* fall through */
 125
 126 _GLOBAL(power7_nap)
 127         mr      r4,r3
 128         li      r3,0
 129         b       power7_powersave_common
 130         /* No return */
 131
 132 _GLOBAL(power7_sleep)
 133         li      r3,1
 134         li      r4,1
 135         b       power7_powersave_common
 136         /* No return */
 137
 138 /*
 139  * Make opal call in realmode. This is a generic function to be called
 140  * from realmode from reset vector. It handles endianess.
 141  *
 142  * r13 - paca pointer
 143  * r1  - stack pointer
 144  * r3  - opal token
 145  */
 146 opal_call_realmode:
 147         mflr    r12
 148         std     r12,_LINK(r1)
 149         ld      r2,PACATOC(r13)
 150         /* Set opal return address */
 151         LOAD_REG_ADDR(r0,return_from_opal_call)
 152         mtlr    r0
 153         /* Handle endian-ness */
 154         li      r0,MSR_LE
 155         mfmsr   r12
 156         andc    r12,r12,r0
 157         mtspr   SPRN_HSRR1,r12
 158         mr      r0,r3                   /* Move opal token to r0 */
 159         LOAD_REG_ADDR(r11,opal)
 160         ld      r12,8(r11)
 161         ld      r2,0(r11)
 162         mtspr   SPRN_HSRR0,r12
 163         hrfid
 164
 165 return_from_opal_call:
 166         FIXUP_ENDIAN
 167         ld      r0,_LINK(r1)
 168         mtlr    r0
 169         blr
 170
 171 #define CHECK_HMI_INTERRUPT                                             \
 172         mfspr   r0,SPRN_SRR1;                                           \
 173 BEGIN_FTR_SECTION_NESTED(66);                                           \
 174         rlwinm  r0,r0,45-31,0xf;  /* extract wake reason field (P8) */  \
 175 FTR_SECTION_ELSE_NESTED(66);                                            \
 176         rlwinm  r0,r0,45-31,0xe;  /* P7 wake reason field is 3 bits */  \
 177 ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 66);                \
 178         cmpwi   r0,0xa;                 /* Hypervisor maintenance ? */  \
 179         bne     20f;                                                    \
 180         /* Invoke opal call to handle hmi */                            \
 181         ld      r2,PACATOC(r13);                                        \
 182         ld      r1,PACAR1(r13);                                         \
 183         std     r3,ORIG_GPR3(r1);       /* Save original r3 */          \
 184         li      r3,OPAL_HANDLE_HMI;     /* Pass opal token argument*/   \
 185         bl      opal_call_realmode;                                     \
 186         ld      r3,ORIG_GPR3(r1);       /* Restore original r3 */       \
 187 20:     nop;
 188
 189
 190 _GLOBAL(power7_wakeup_tb_loss)
 191         ld      r2,PACATOC(r13);
 192         ld      r1,PACAR1(r13)
 193
 194 BEGIN_FTR_SECTION
 195         CHECK_HMI_INTERRUPT
 196 END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
 197         /* Time base re-sync */
 198         li      r3,OPAL_RESYNC_TIMEBASE
 199         bl      opal_call_realmode;
 200
 201         /* TODO: Check r3 for failure */
 202
 203         REST_NVGPRS(r1)
 204         REST_GPR(2, r1)
 205         ld      r3,_CCR(r1)
 206         ld      r4,_MSR(r1)
 207         ld      r5,_NIP(r1)
 208         addi    r1,r1,INT_FRAME_SIZE
 209         mtcr    r3
 210         mfspr   r3,SPRN_SRR1            /* Return SRR1 */
 211         mtspr   SPRN_SRR1,r4
 212         mtspr   SPRN_SRR0,r5
 213         rfid
 214
 215 /*
 216  * R3 here contains the value that will be returned to the caller
 217  * of power7_nap.
 218  */
 219 _GLOBAL(power7_wakeup_loss)
 220         ld      r1,PACAR1(r13)
 221 BEGIN_FTR_SECTION
 222         CHECK_HMI_INTERRUPT
 223 END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
 224         REST_NVGPRS(r1)
 225         REST_GPR(2, r1)
 226         ld      r6,_CCR(r1)
 227         ld      r4,_MSR(r1)
 228         ld      r5,_NIP(r1)
 229         addi    r1,r1,INT_FRAME_SIZE
 230         mtcr    r6
 231         mtspr   SPRN_SRR1,r4
 232         mtspr   SPRN_SRR0,r5
 233         rfid
 234
 235 /*
 236  * R3 here contains the value that will be returned to the caller
 237  * of power7_nap.
 238  */
 239 _GLOBAL(power7_wakeup_noloss)
 240         lbz     r0,PACA_NAPSTATELOST(r13)
 241         cmpwi   r0,0
 242         bne     power7_wakeup_loss
 243 BEGIN_FTR_SECTION
 244         CHECK_HMI_INTERRUPT
 245 END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
 246         ld      r1,PACAR1(r13)
 247         ld      r4,_MSR(r1)
 248         ld      r5,_NIP(r1)
 249         addi    r1,r1,INT_FRAME_SIZE
 250         mtspr   SPRN_SRR1,r4
 251         mtspr   SPRN_SRR0,r5
 252         rfid