Merge rsync://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6] / arch / powerpc / platforms / cell / pervasive.c
1 /*
2  * CBE Pervasive Monitor and Debug
3  *
4  * (C) Copyright IBM Corporation 2005
5  *
6  * Authors: Maximino Aguilar (maguilar@us.ibm.com)
7  *          Michael N. Day (mnday@us.ibm.com)
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2, or (at your option)
12  * any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22  */
23
24 #undef DEBUG
25
26 #include <linux/interrupt.h>
27 #include <linux/irq.h>
28 #include <linux/percpu.h>
29 #include <linux/types.h>
30 #include <linux/kallsyms.h>
31
32 #include <asm/io.h>
33 #include <asm/machdep.h>
34 #include <asm/prom.h>
35 #include <asm/pgtable.h>
36 #include <asm/reg.h>
37
38 #include "pervasive.h"
39 #include "cbe_regs.h"
40
41 static DEFINE_SPINLOCK(cbe_pervasive_lock);
42
43 static void __init cbe_enable_pause_zero(void)
44 {
45         unsigned long thread_switch_control;
46         unsigned long temp_register;
47         struct cbe_pmd_regs __iomem *pregs;
48
49         spin_lock_irq(&cbe_pervasive_lock);
50         pregs = cbe_get_cpu_pmd_regs(smp_processor_id());
51         if (pregs == NULL)
52                 goto out;
53
54         pr_debug("Power Management: CPU %d\n", smp_processor_id());
55
56          /* Enable Pause(0) control bit */
57         temp_register = in_be64(&pregs->pm_control);
58
59         out_be64(&pregs->pm_control,
60                  temp_register | CBE_PMD_PAUSE_ZERO_CONTROL);
61
62         /* Enable DEC and EE interrupt request */
63         thread_switch_control  = mfspr(SPRN_TSC_CELL);
64         thread_switch_control |= TSC_CELL_EE_ENABLE | TSC_CELL_EE_BOOST;
65
66         switch ((mfspr(SPRN_CTRLF) & CTRL_CT)) {
67         case CTRL_CT0:
68                 thread_switch_control |= TSC_CELL_DEC_ENABLE_0;
69                 break;
70         case CTRL_CT1:
71                 thread_switch_control |= TSC_CELL_DEC_ENABLE_1;
72                 break;
73         default:
74                 printk(KERN_WARNING "%s: unknown configuration\n",
75                         __FUNCTION__);
76                 break;
77         }
78
79         mtspr(SPRN_TSC_CELL, thread_switch_control);
80
81 out:
82         spin_unlock_irq(&cbe_pervasive_lock);
83 }
84
85 static void cbe_idle(void)
86 {
87         unsigned long ctrl;
88
89         /* Why do we do that on every idle ? Couldn't that be done once for
90          * all or do we lose the state some way ? Also, the pm_control
91          * register setting, that can't be set once at boot ? We really want
92          * to move that away in order to implement a simple powersave
93          */
94         cbe_enable_pause_zero();
95
96         while (1) {
97                 if (!need_resched()) {
98                         local_irq_disable();
99                         while (!need_resched()) {
100                                 /* go into low thread priority */
101                                 HMT_low();
102
103                                 /*
104                                  * atomically disable thread execution
105                                  * and runlatch.
106                                  * External and Decrementer exceptions
107                                  * are still handled when the thread
108                                  * is disabled but now enter in
109                                  * cbe_system_reset_exception()
110                                  */
111                                 ctrl = mfspr(SPRN_CTRLF);
112                                 ctrl &= ~(CTRL_RUNLATCH | CTRL_TE);
113                                 mtspr(SPRN_CTRLT, ctrl);
114                         }
115                         /* restore thread prio */
116                         HMT_medium();
117                         local_irq_enable();
118                 }
119
120                 /*
121                  * turn runlatch on again before scheduling the
122                  * process we just woke up
123                  */
124                 ppc64_runlatch_on();
125
126                 preempt_enable_no_resched();
127                 schedule();
128                 preempt_disable();
129         }
130 }
131
132 static int cbe_system_reset_exception(struct pt_regs *regs)
133 {
134         switch (regs->msr & SRR1_WAKEMASK) {
135         case SRR1_WAKEEE:
136                 do_IRQ(regs);
137                 break;
138         case SRR1_WAKEDEC:
139                 timer_interrupt(regs);
140                 break;
141         case SRR1_WAKEMT:
142                 break;
143 #ifdef CONFIG_CBE_RAS
144         case SRR1_WAKESYSERR:
145                 cbe_system_error_exception(regs);
146                 break;
147         case SRR1_WAKETHERM:
148                 cbe_thermal_exception(regs);
149                 break;
150 #endif /* CONFIG_CBE_RAS */
151         default:
152                 /* do system reset */
153                 return 0;
154         }
155         /* everything handled */
156         return 1;
157 }
158
159 void __init cbe_pervasive_init(void)
160 {
161         if (!cpu_has_feature(CPU_FTR_PAUSE_ZERO))
162                 return;
163
164         ppc_md.idle_loop = cbe_idle;
165         ppc_md.system_reset_exception = cbe_system_reset_exception;
166 }