summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms/cell/pervasive.c
blob: e0e051c675dd129d1116cb7a43db71c819a805b7 (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
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
/*
 * 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/config.h>
#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"

static DEFINE_SPINLOCK(cbe_pervasive_lock);
struct cbe_pervasive {
	struct pmd_regs __iomem *regs;
	unsigned int thread;
};

/* can't use per_cpu from setup_arch */
static struct cbe_pervasive cbe_pervasive[NR_CPUS];

static void __init cbe_enable_pause_zero(void)
{
	unsigned long thread_switch_control;
	unsigned long temp_register;
	struct cbe_pervasive *p;
	int thread;

	spin_lock_irq(&cbe_pervasive_lock);
	p = &cbe_pervasive[smp_processor_id()];

	if (!cbe_pervasive->regs)
		goto out;

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

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

	out_be64(&p->regs->pm_control,
		 temp_register|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;
		thread = 0;
		break;
	case CTRL_CT1:
		thread_switch_control |= TSC_CELL_DEC_ENABLE_1;
		thread = 1;
		break;
	default:
		printk(KERN_WARNING "%s: unknown configuration\n",
			__FUNCTION__);
		thread = -1;
		break;
	}

	if (p->thread != thread)
		printk(KERN_WARNING "%s: device tree inconsistant, "
				     "cpu %i: %d/%d\n", __FUNCTION__,
				     smp_processor_id(),
				     p->thread, thread);

	mtspr(SPRN_TSC_CELL, thread_switch_control);

out:
	spin_unlock_irq(&cbe_pervasive_lock);
}

static void cbe_idle(void)
{
	unsigned long ctrl;

	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:
		/* no action required */
		break;
	default:
		/* do system reset */
		return 0;
	}
	/* everything handled */
	return 1;
}

static int __init cbe_find_pmd_mmio(int cpu, struct cbe_pervasive *p)
{
	struct device_node *node;
	unsigned int *int_servers;
	char *addr;
	unsigned long real_address;
	unsigned int size;

	struct pmd_regs __iomem *pmd_mmio_area;
	int hardid, thread;
	int proplen;

	pmd_mmio_area = NULL;
	hardid = get_hard_smp_processor_id(cpu);
	for (node = NULL; (node = of_find_node_by_type(node, "cpu"));) {
		int_servers = (void *) get_property(node,
				"ibm,ppc-interrupt-server#s", &proplen);
		if (!int_servers) {
			printk(KERN_WARNING "%s misses "
				"ibm,ppc-interrupt-server#s property",
				node->full_name);
			continue;
		}
		for (thread = 0; thread < proplen / sizeof (int); thread++) {
			if (hardid == int_servers[thread]) {
				addr = get_property(node, "pervasive", NULL);
				goto found;
			}
		}
	}

	printk(KERN_WARNING "%s: CPU %d not found\n", __FUNCTION__, cpu);
	return -EINVAL;

found:
	real_address = *(unsigned long*) addr;
	addr += sizeof (unsigned long);
	size = *(unsigned int*) addr;

	pr_debug("pervasive area for CPU %d at %lx, size %x\n",
			cpu, real_address, size);
	p->regs = __ioremap(real_address, size, _PAGE_NO_CACHE);
	p->thread = thread;
	return 0;
}

void __init cell_pervasive_init(void)
{
	struct cbe_pervasive *p;
	int cpu;
	int ret;

	if (!cpu_has_feature(CPU_FTR_PAUSE_ZERO))
		return;

	for_each_cpu(cpu) {
		p = &cbe_pervasive[cpu];
		ret = cbe_find_pmd_mmio(cpu, p);
		if (ret)
			return;
	}

	ppc_md.idle_loop = cbe_idle;
	ppc_md.system_reset_exception = cbe_system_reset_exception;
}
OpenPOWER on IntegriCloud