diff options
Diffstat (limited to 'arch/ppc/kernel/idle_6xx.S')
-rw-r--r-- | arch/ppc/kernel/idle_6xx.S | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/arch/ppc/kernel/idle_6xx.S b/arch/ppc/kernel/idle_6xx.S new file mode 100644 index 000000000000..25d009c75f7b --- /dev/null +++ b/arch/ppc/kernel/idle_6xx.S | |||
@@ -0,0 +1,233 @@ | |||
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 | * Make sure no rest of NAP mode remains in HID0, save default | ||
32 | * values for some CPU specific registers. Called with r24 | ||
33 | * containing CPU number and r3 reloc offset | ||
34 | */ | ||
35 | _GLOBAL(init_idle_6xx) | ||
36 | BEGIN_FTR_SECTION | ||
37 | mfspr r4,SPRN_HID0 | ||
38 | rlwinm r4,r4,0,10,8 /* Clear NAP */ | ||
39 | mtspr SPRN_HID0, r4 | ||
40 | b 1f | ||
41 | END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP) | ||
42 | blr | ||
43 | 1: | ||
44 | slwi r5,r24,2 | ||
45 | add r5,r5,r3 | ||
46 | BEGIN_FTR_SECTION | ||
47 | mfspr r4,SPRN_MSSCR0 | ||
48 | addis r6,r5, nap_save_msscr0@ha | ||
49 | stw r4,nap_save_msscr0@l(r6) | ||
50 | END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR) | ||
51 | BEGIN_FTR_SECTION | ||
52 | mfspr r4,SPRN_HID1 | ||
53 | addis r6,r5,nap_save_hid1@ha | ||
54 | stw r4,nap_save_hid1@l(r6) | ||
55 | END_FTR_SECTION_IFSET(CPU_FTR_DUAL_PLL_750FX) | ||
56 | blr | ||
57 | |||
58 | /* | ||
59 | * Here is the power_save_6xx function. This could eventually be | ||
60 | * split into several functions & changing the function pointer | ||
61 | * depending on the various features. | ||
62 | */ | ||
63 | _GLOBAL(ppc6xx_idle) | ||
64 | /* Check if we can nap or doze, put HID0 mask in r3 | ||
65 | */ | ||
66 | lis r3, 0 | ||
67 | BEGIN_FTR_SECTION | ||
68 | lis r3,HID0_DOZE@h | ||
69 | END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE) | ||
70 | BEGIN_FTR_SECTION | ||
71 | /* We must dynamically check for the NAP feature as it | ||
72 | * can be cleared by CPU init after the fixups are done | ||
73 | */ | ||
74 | lis r4,cur_cpu_spec@ha | ||
75 | lwz r4,cur_cpu_spec@l(r4) | ||
76 | lwz r4,CPU_SPEC_FEATURES(r4) | ||
77 | andi. r0,r4,CPU_FTR_CAN_NAP | ||
78 | beq 1f | ||
79 | /* Now check if user or arch enabled NAP mode */ | ||
80 | lis r4,powersave_nap@ha | ||
81 | lwz r4,powersave_nap@l(r4) | ||
82 | cmpwi 0,r4,0 | ||
83 | beq 1f | ||
84 | lis r3,HID0_NAP@h | ||
85 | 1: | ||
86 | END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP) | ||
87 | cmpwi 0,r3,0 | ||
88 | beqlr | ||
89 | |||
90 | /* Clear MSR:EE */ | ||
91 | mfmsr r7 | ||
92 | rlwinm r0,r7,0,17,15 | ||
93 | mtmsr r0 | ||
94 | |||
95 | /* Check current_thread_info()->flags */ | ||
96 | rlwinm r4,r1,0,0,18 | ||
97 | lwz r4,TI_FLAGS(r4) | ||
98 | andi. r0,r4,_TIF_NEED_RESCHED | ||
99 | beq 1f | ||
100 | mtmsr r7 /* out of line this ? */ | ||
101 | blr | ||
102 | 1: | ||
103 | /* Some pre-nap cleanups needed on some CPUs */ | ||
104 | andis. r0,r3,HID0_NAP@h | ||
105 | beq 2f | ||
106 | BEGIN_FTR_SECTION | ||
107 | /* Disable L2 prefetch on some 745x and try to ensure | ||
108 | * L2 prefetch engines are idle. As explained by errata | ||
109 | * text, we can't be sure they are, we just hope very hard | ||
110 | * that well be enough (sic !). At least I noticed Apple | ||
111 | * doesn't even bother doing the dcbf's here... | ||
112 | */ | ||
113 | mfspr r4,SPRN_MSSCR0 | ||
114 | rlwinm r4,r4,0,0,29 | ||
115 | sync | ||
116 | mtspr SPRN_MSSCR0,r4 | ||
117 | sync | ||
118 | isync | ||
119 | lis r4,KERNELBASE@h | ||
120 | dcbf 0,r4 | ||
121 | dcbf 0,r4 | ||
122 | dcbf 0,r4 | ||
123 | dcbf 0,r4 | ||
124 | END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR) | ||
125 | #ifdef DEBUG | ||
126 | lis r6,nap_enter_count@ha | ||
127 | lwz r4,nap_enter_count@l(r6) | ||
128 | addi r4,r4,1 | ||
129 | stw r4,nap_enter_count@l(r6) | ||
130 | #endif | ||
131 | 2: | ||
132 | BEGIN_FTR_SECTION | ||
133 | /* Go to low speed mode on some 750FX */ | ||
134 | lis r4,powersave_lowspeed@ha | ||
135 | lwz r4,powersave_lowspeed@l(r4) | ||
136 | cmpwi 0,r4,0 | ||
137 | beq 1f | ||
138 | mfspr r4,SPRN_HID1 | ||
139 | oris r4,r4,0x0001 | ||
140 | mtspr SPRN_HID1,r4 | ||
141 | 1: | ||
142 | END_FTR_SECTION_IFSET(CPU_FTR_DUAL_PLL_750FX) | ||
143 | |||
144 | /* Go to NAP or DOZE now */ | ||
145 | mfspr r4,SPRN_HID0 | ||
146 | lis r5,(HID0_NAP|HID0_SLEEP)@h | ||
147 | BEGIN_FTR_SECTION | ||
148 | oris r5,r5,HID0_DOZE@h | ||
149 | END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE) | ||
150 | andc r4,r4,r5 | ||
151 | or r4,r4,r3 | ||
152 | BEGIN_FTR_SECTION | ||
153 | oris r4,r4,HID0_DPM@h /* that should be done once for all */ | ||
154 | END_FTR_SECTION_IFCLR(CPU_FTR_NO_DPM) | ||
155 | mtspr SPRN_HID0,r4 | ||
156 | BEGIN_FTR_SECTION | ||
157 | DSSALL | ||
158 | sync | ||
159 | END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) | ||
160 | ori r7,r7,MSR_EE /* Could be ommited (already set) */ | ||
161 | oris r7,r7,MSR_POW@h | ||
162 | sync | ||
163 | isync | ||
164 | mtmsr r7 | ||
165 | isync | ||
166 | sync | ||
167 | blr | ||
168 | |||
169 | /* | ||
170 | * Return from NAP/DOZE mode, restore some CPU specific registers, | ||
171 | * we are called with DR/IR still off and r2 containing physical | ||
172 | * address of current. | ||
173 | */ | ||
174 | _GLOBAL(power_save_6xx_restore) | ||
175 | mfspr r11,SPRN_HID0 | ||
176 | rlwinm. r11,r11,0,10,8 /* Clear NAP & copy NAP bit !state to cr1 EQ */ | ||
177 | cror 4*cr1+eq,4*cr0+eq,4*cr0+eq | ||
178 | BEGIN_FTR_SECTION | ||
179 | rlwinm r11,r11,0,9,7 /* Clear DOZE */ | ||
180 | END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE) | ||
181 | mtspr SPRN_HID0, r11 | ||
182 | |||
183 | #ifdef DEBUG | ||
184 | beq cr1,1f | ||
185 | lis r11,(nap_return_count-KERNELBASE)@ha | ||
186 | lwz r9,nap_return_count@l(r11) | ||
187 | addi r9,r9,1 | ||
188 | stw r9,nap_return_count@l(r11) | ||
189 | 1: | ||
190 | #endif | ||
191 | |||
192 | rlwinm r9,r1,0,0,18 | ||
193 | tophys(r9,r9) | ||
194 | lwz r11,TI_CPU(r9) | ||
195 | slwi r11,r11,2 | ||
196 | /* Todo make sure all these are in the same page | ||
197 | * and load r22 (@ha part + CPU offset) only once | ||
198 | */ | ||
199 | BEGIN_FTR_SECTION | ||
200 | beq cr1,1f | ||
201 | addis r9,r11,(nap_save_msscr0-KERNELBASE)@ha | ||
202 | lwz r9,nap_save_msscr0@l(r9) | ||
203 | mtspr SPRN_MSSCR0, r9 | ||
204 | sync | ||
205 | isync | ||
206 | 1: | ||
207 | END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR) | ||
208 | BEGIN_FTR_SECTION | ||
209 | addis r9,r11,(nap_save_hid1-KERNELBASE)@ha | ||
210 | lwz r9,nap_save_hid1@l(r9) | ||
211 | mtspr SPRN_HID1, r9 | ||
212 | END_FTR_SECTION_IFSET(CPU_FTR_DUAL_PLL_750FX) | ||
213 | b transfer_to_handler_cont | ||
214 | |||
215 | .data | ||
216 | |||
217 | _GLOBAL(nap_save_msscr0) | ||
218 | .space 4*NR_CPUS | ||
219 | |||
220 | _GLOBAL(nap_save_hid1) | ||
221 | .space 4*NR_CPUS | ||
222 | |||
223 | _GLOBAL(powersave_nap) | ||
224 | .long 0 | ||
225 | _GLOBAL(powersave_lowspeed) | ||
226 | .long 0 | ||
227 | |||
228 | #ifdef DEBUG | ||
229 | _GLOBAL(nap_enter_count) | ||
230 | .space 4 | ||
231 | _GLOBAL(nap_return_count) | ||
232 | .space 4 | ||
233 | #endif | ||