tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * pmi backend for the cbe_cpufreq driver
3 *
4 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
5 *
6 * Author: Christian Krafft <krafft@de.ibm.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
11 * any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 */
22
23#include <linux/kernel.h>
24#include <linux/types.h>
25#include <linux/timer.h>
26#include <linux/init.h>
27#include <linux/of_platform.h>
28
29#include <asm/processor.h>
30#include <asm/prom.h>
31#include <asm/pmi.h>
32#include <asm/cell-regs.h>
33
34#ifdef DEBUG
35#include <asm/time.h>
36#endif
37
38#include "ppc_cbe_cpufreq.h"
39
40static u8 pmi_slow_mode_limit[MAX_CBE];
41
42bool cbe_cpufreq_has_pmi = false;
43EXPORT_SYMBOL_GPL(cbe_cpufreq_has_pmi);
44
45/*
46 * hardware specific functions
47 */
48
49int cbe_cpufreq_set_pmode_pmi(int cpu, unsigned int pmode)
50{
51 int ret;
52 pmi_message_t pmi_msg;
53#ifdef DEBUG
54 long time;
55#endif
56 pmi_msg.type = PMI_TYPE_FREQ_CHANGE;
57 pmi_msg.data1 = cbe_cpu_to_node(cpu);
58 pmi_msg.data2 = pmode;
59
60#ifdef DEBUG
61 time = jiffies;
62#endif
63 pmi_send_message(pmi_msg);
64
65#ifdef DEBUG
66 time = jiffies - time;
67 time = jiffies_to_msecs(time);
68 pr_debug("had to wait %lu ms for a transition using " \
69 "PMI\n", time);
70#endif
71 ret = pmi_msg.data2;
72 pr_debug("PMI returned slow mode %d\n", ret);
73
74 return ret;
75}
76EXPORT_SYMBOL_GPL(cbe_cpufreq_set_pmode_pmi);
77
78
79static void cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg)
80{
81 u8 node, slow_mode;
82
83 BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE);
84
85 node = pmi_msg.data1;
86 slow_mode = pmi_msg.data2;
87
88 pmi_slow_mode_limit[node] = slow_mode;
89
90 pr_debug("cbe_handle_pmi: node: %d max_freq: %d\n", node, slow_mode);
91}
92
93static int pmi_notifier(struct notifier_block *nb,
94 unsigned long event, void *data)
95{
96 struct cpufreq_policy *policy = data;
97 struct cpufreq_frequency_table *cbe_freqs = policy->freq_table;
98 u8 node;
99
100 /* Should this really be called for CPUFREQ_ADJUST and CPUFREQ_NOTIFY
101 * policy events?)
102 */
103 if (event == CPUFREQ_START)
104 return 0;
105
106 node = cbe_cpu_to_node(policy->cpu);
107
108 pr_debug("got notified, event=%lu, node=%u\n", event, node);
109
110 if (pmi_slow_mode_limit[node] != 0) {
111 pr_debug("limiting node %d to slow mode %d\n",
112 node, pmi_slow_mode_limit[node]);
113
114 cpufreq_verify_within_limits(policy, 0,
115
116 cbe_freqs[pmi_slow_mode_limit[node]].frequency);
117 }
118
119 return 0;
120}
121
122static struct notifier_block pmi_notifier_block = {
123 .notifier_call = pmi_notifier,
124};
125
126static struct pmi_handler cbe_pmi_handler = {
127 .type = PMI_TYPE_FREQ_CHANGE,
128 .handle_pmi_message = cbe_cpufreq_handle_pmi,
129};
130
131
132
133static int __init cbe_cpufreq_pmi_init(void)
134{
135 cbe_cpufreq_has_pmi = pmi_register_handler(&cbe_pmi_handler) == 0;
136
137 if (!cbe_cpufreq_has_pmi)
138 return -ENODEV;
139
140 cpufreq_register_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);
141
142 return 0;
143}
144device_initcall(cbe_cpufreq_pmi_init);