aboutsummaryrefslogtreecommitdiff
path: root/arch/powerpc/platforms/cell/pervasive.c
blob: 9f2e4ed20a57d8af2af6cc76ca4586ce7e793681 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
/*
 * CBE Pervasive Monitor and Debug
 *
 * (C) Copyright IBM Corporation 2005
 *
 * Authors: Maximino Aguilar (maguilar@us.ibm.com)
 *          Michael N. Day (mnday@us.ibm.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#undef DEBUG

#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/percpu.h>
#include <linux/types.h>
#include <linux/kallsyms.h>

#include <asm/io.h>
#include <asm/machdep.h>
#include <asm/prom.h>
#include <asm/pgtable.h>
#include <asm/reg.h>

#include "pervasive.h"
#include "cbe_regs.h"

static DEFINE_SPINLOCK(cbe_pervasive_lock);

static void __init cbe_enable_pause_zero(void)
{
	unsigned long thread_switch_control;
	unsigned long temp_register;
	struct cbe_pmd_regs __iomem *pregs;

	spin_lock_irq(&cbe_pervasive_lock);
	pregs = cbe_get_cpu_pmd_regs(smp_processor_id());
	if (pregs == NULL)
		goto out;

	pr_debug("Power Management: CPU %d\n", smp_processor_id());

	 /* Enable Pause(0) control bit */
	temp_register = in_be64(&pregs->pm_control);

	out_be64(&pregs->pm_control,
		 temp_register | CBE_PMD_PAUSE_ZERO_CONTROL);

	/* Enable DEC and EE interrupt request */
	thread_switch_control  = mfspr(SPRN_TSC_CELL);
	thread_switch_control |= TSC_CELL_EE_ENABLE | TSC_CELL_EE_BOOST;

	switch ((mfspr(SPRN_CTRLF) & CTRL_CT)) {
	case CTRL_CT0:
		thread_switch_control |= TSC_CELL_DEC_ENABLE_0;
		break;
	case CTRL_CT1:
		thread_switch_control |= TSC_CELL_DEC_ENABLE_1;
		break;
	default:
		printk(KERN_WARNING "%s: unknown configuration\n",
			__FUNCTION__);
		break;
	}

	mtspr(SPRN_TSC_CELL, thread_switch_control);

out:
	spin_unlock_irq(&cbe_pervasive_lock);
}

static void cbe_idle(void)
{
	unsigned long ctrl;

	/* Why do we do that on every idle ? Couldn't that be done once for
	 * all or do we lose the state some way ? Also, the pm_control
	 * register setting, that can't be set once at boot ? We really want
	 * to move that away in order to implement a simple powersave
	 */
	cbe_enable_pause_zero();

	while (1) {
		if (!need_resched()) {
			local_irq_disable();
			while (!need_resched()) {
				/* go into low thread priority */
				HMT_low();

				/*
				 * atomically disable thread execution
				 * and runlatch.
				 * External and Decrementer exceptions
				 * are still handled when the thread
				 * is disabled but now enter in
				 * cbe_system_reset_exception()
				 */
				ctrl = mfspr(SPRN_CTRLF);
				ctrl &= ~(CTRL_RUNLATCH | CTRL_TE);
				mtspr(SPRN_CTRLT, ctrl);
			}
			/* restore thread prio */
			HMT_medium();
			local_irq_enable();
		}

		/*
		 * turn runlatch on again before scheduling the
		 * process we just woke up
		 */
		ppc64_runlatch_on();

		preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}

static int cbe_system_reset_exception(struct pt_regs *regs)
{
	switch (regs->msr & SRR1_WAKEMASK) {
	case SRR1_WAKEEE:
		do_IRQ(regs);
		break;
	case SRR1_WAKEDEC:
		timer_interrupt(regs);
		break;
	case SRR1_WAKEMT:
		break;
#ifdef CONFIG_CBE_RAS
	case SRR1_WAKESYSERR:
		cbe_system_error_exception(regs);
		break;
	case SRR1_WAKETHERM:
		cbe_thermal_exception(regs);
		break;
#endif /* CONFIG_CBE_RAS */
	default:
		/* do system reset */
		return 0;
	}
	/* everything handled */
	return 1;
}

void __init cbe_pervasive_init(void)
{
	if (!cpu_has_feature(CPU_FTR_PAUSE_ZERO))
		return;

	ppc_md.idle_loop = cbe_idle;
	ppc_md.system_reset_exception = cbe_system_reset_exception;
}