| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * This file contains the power_save function for 6xx & 7xxx CPUs |
| 3 | * rewritten in assembler |
| 4 | * |
| 5 | * Warning ! This code assumes that if your machine has a 750fx |
| 6 | * it will have PLL 1 set to low speed mode (used during NAP/DOZE). |
| 7 | * if this is not the case some additional changes will have to |
| 8 | * be done to check a runtime var (a bit like powersave-nap) |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public License |
| 12 | * as published by the Free Software Foundation; either version |
| 13 | * 2 of the License, or (at your option) any later version. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/config.h> |
| 17 | #include <linux/threads.h> |
| 18 | #include <asm/processor.h> |
| 19 | #include <asm/page.h> |
| 20 | #include <asm/cputable.h> |
| 21 | #include <asm/thread_info.h> |
| 22 | #include <asm/ppc_asm.h> |
| 23 | #include <asm/offsets.h> |
| 24 | |
| 25 | #undef DEBUG |
| 26 | |
| 27 | .text |
| 28 | |
| 29 | /* |
| 30 | * Init idle, called at early CPU setup time from head.S for each CPU |
| 31 | * So nothing for now. Called with r24 containing CPU number and r3 |
| 32 | * reloc offset |
| 33 | */ |
| 34 | .globl init_idle_power4 |
| 35 | init_idle_power4: |
| 36 | blr |
| 37 | |
| 38 | /* |
| 39 | * Here is the power_save_6xx function. This could eventually be |
| 40 | * split into several functions & changing the function pointer |
| 41 | * depending on the various features. |
| 42 | */ |
| 43 | .globl power4_idle |
| 44 | power4_idle: |
| 45 | BEGIN_FTR_SECTION |
| 46 | blr |
| 47 | END_FTR_SECTION_IFCLR(CPU_FTR_CAN_NAP) |
| 48 | /* We must dynamically check for the NAP feature as it |
| 49 | * can be cleared by CPU init after the fixups are done |
| 50 | */ |
| 51 | lis r4,cur_cpu_spec@ha |
| 52 | lwz r4,cur_cpu_spec@l(r4) |
| 53 | lwz r4,CPU_SPEC_FEATURES(r4) |
| 54 | andi. r0,r4,CPU_FTR_CAN_NAP |
| 55 | beqlr |
| 56 | /* Now check if user or arch enabled NAP mode */ |
| 57 | lis r4,powersave_nap@ha |
| 58 | lwz r4,powersave_nap@l(r4) |
| 59 | cmpwi 0,r4,0 |
| 60 | beqlr |
| 61 | |
| 62 | /* Clear MSR:EE */ |
| 63 | mfmsr r7 |
| 64 | rlwinm r0,r7,0,17,15 |
| 65 | mtmsr r0 |
| 66 | |
| 67 | /* Check current_thread_info()->flags */ |
| 68 | rlwinm r4,r1,0,0,18 |
| 69 | lwz r4,TI_FLAGS(r4) |
| 70 | andi. r0,r4,_TIF_NEED_RESCHED |
| 71 | beq 1f |
| 72 | mtmsr r7 /* out of line this ? */ |
| 73 | blr |
| 74 | 1: |
| 75 | /* Go to NAP now */ |
| 76 | BEGIN_FTR_SECTION |
| 77 | DSSALL |
| 78 | sync |
| 79 | END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) |
| 80 | ori r7,r7,MSR_EE /* Could be ommited (already set) */ |
| 81 | oris r7,r7,MSR_POW@h |
| 82 | sync |
| 83 | isync |
| 84 | mtmsr r7 |
| 85 | isync |
| 86 | sync |
| 87 | blr |
| 88 | |
| 89 | .globl powersave_nap |
| 90 | powersave_nap: |
| 91 | .long 0 |