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Commit | Line | Data |
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1da177e4 LT |
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 |