1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * pmi backend for the cbe_cpufreq driver
4 *
5 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
6 *
7 * Author: Christian Krafft <krafft@de.ibm.com>
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/types.h>
12 #include <linux/timer.h>
13 #include <linux/init.h>
14 #include <linux/pm_qos.h>
15 #include <linux/slab.h>
16
17 #include <asm/processor.h>
18 #include <asm/pmi.h>
19 #include <asm/cell-regs.h>
20
21 #ifdef DEBUG
22 #include <asm/time.h>
23 #endif
24
25 #include "ppc_cbe_cpufreq.h"
26
27 bool cbe_cpufreq_has_pmi = false;
28 EXPORT_SYMBOL_GPL(cbe_cpufreq_has_pmi);
29
30 /*
31 * hardware specific functions
32 */
33
cbe_cpufreq_set_pmode_pmi(int cpu,unsigned int pmode)34 int cbe_cpufreq_set_pmode_pmi(int cpu, unsigned int pmode)
35 {
36 int ret;
37 pmi_message_t pmi_msg;
38 #ifdef DEBUG
39 long time;
40 #endif
41 pmi_msg.type = PMI_TYPE_FREQ_CHANGE;
42 pmi_msg.data1 = cbe_cpu_to_node(cpu);
43 pmi_msg.data2 = pmode;
44
45 #ifdef DEBUG
46 time = jiffies;
47 #endif
48 pmi_send_message(pmi_msg);
49
50 #ifdef DEBUG
51 time = jiffies - time;
52 time = jiffies_to_msecs(time);
53 pr_debug("had to wait %lu ms for a transition using " \
54 "PMI\n", time);
55 #endif
56 ret = pmi_msg.data2;
57 pr_debug("PMI returned slow mode %d\n", ret);
58
59 return ret;
60 }
61 EXPORT_SYMBOL_GPL(cbe_cpufreq_set_pmode_pmi);
62
63
cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg)64 static void cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg)
65 {
66 struct cpufreq_policy *policy;
67 struct freq_qos_request *req;
68 u8 node, slow_mode;
69 int cpu, ret;
70
71 BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE);
72
73 node = pmi_msg.data1;
74 slow_mode = pmi_msg.data2;
75
76 cpu = cbe_node_to_cpu(node);
77
78 pr_debug("cbe_handle_pmi: node: %d max_freq: %d\n", node, slow_mode);
79
80 policy = cpufreq_cpu_get(cpu);
81 if (!policy) {
82 pr_warn("cpufreq policy not found cpu%d\n", cpu);
83 return;
84 }
85
86 req = policy->driver_data;
87
88 ret = freq_qos_update_request(req,
89 policy->freq_table[slow_mode].frequency);
90 if (ret < 0)
91 pr_warn("Failed to update freq constraint: %d\n", ret);
92 else
93 pr_debug("limiting node %d to slow mode %d\n", node, slow_mode);
94
95 cpufreq_cpu_put(policy);
96 }
97
98 static struct pmi_handler cbe_pmi_handler = {
99 .type = PMI_TYPE_FREQ_CHANGE,
100 .handle_pmi_message = cbe_cpufreq_handle_pmi,
101 };
102
cbe_cpufreq_pmi_policy_init(struct cpufreq_policy * policy)103 void cbe_cpufreq_pmi_policy_init(struct cpufreq_policy *policy)
104 {
105 struct freq_qos_request *req;
106 int ret;
107
108 if (!cbe_cpufreq_has_pmi)
109 return;
110
111 req = kzalloc(sizeof(*req), GFP_KERNEL);
112 if (!req)
113 return;
114
115 ret = freq_qos_add_request(&policy->constraints, req, FREQ_QOS_MAX,
116 policy->freq_table[0].frequency);
117 if (ret < 0) {
118 pr_err("Failed to add freq constraint (%d)\n", ret);
119 kfree(req);
120 return;
121 }
122
123 policy->driver_data = req;
124 }
125 EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_policy_init);
126
cbe_cpufreq_pmi_policy_exit(struct cpufreq_policy * policy)127 void cbe_cpufreq_pmi_policy_exit(struct cpufreq_policy *policy)
128 {
129 struct freq_qos_request *req = policy->driver_data;
130
131 if (cbe_cpufreq_has_pmi) {
132 freq_qos_remove_request(req);
133 kfree(req);
134 }
135 }
136 EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_policy_exit);
137
cbe_cpufreq_pmi_init(void)138 void cbe_cpufreq_pmi_init(void)
139 {
140 if (!pmi_register_handler(&cbe_pmi_handler))
141 cbe_cpufreq_has_pmi = true;
142 }
143 EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_init);
144
cbe_cpufreq_pmi_exit(void)145 void cbe_cpufreq_pmi_exit(void)
146 {
147 pmi_unregister_handler(&cbe_pmi_handler);
148 cbe_cpufreq_has_pmi = false;
149 }
150 EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_exit);
151
