xref: /openbmc/linux/drivers/char/ipmi/ipmi_powernv.c (revision c819e2cf)
1 /*
2  * PowerNV OPAL IPMI driver
3  *
4  * Copyright 2014 IBM Corp.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the Free
8  * Software Foundation; either version 2 of the License, or (at your option)
9  * any later version.
10  */
11 
12 #define pr_fmt(fmt)        "ipmi-powernv: " fmt
13 
14 #include <linux/ipmi_smi.h>
15 #include <linux/list.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 
19 #include <asm/opal.h>
20 
21 
22 struct ipmi_smi_powernv {
23 	u64			interface_id;
24 	struct ipmi_device_id	ipmi_id;
25 	ipmi_smi_t		intf;
26 	u64			event;
27 	struct notifier_block	event_nb;
28 
29 	/**
30 	 * We assume that there can only be one outstanding request, so
31 	 * keep the pending message in cur_msg. We protect this from concurrent
32 	 * updates through send & recv calls, (and consequently opal_msg, which
33 	 * is in-use when cur_msg is set) with msg_lock
34 	 */
35 	spinlock_t		msg_lock;
36 	struct ipmi_smi_msg	*cur_msg;
37 	struct opal_ipmi_msg	*opal_msg;
38 };
39 
40 static int ipmi_powernv_start_processing(void *send_info, ipmi_smi_t intf)
41 {
42 	struct ipmi_smi_powernv *smi = send_info;
43 
44 	smi->intf = intf;
45 	return 0;
46 }
47 
48 static void send_error_reply(struct ipmi_smi_powernv *smi,
49 		struct ipmi_smi_msg *msg, u8 completion_code)
50 {
51 	msg->rsp[0] = msg->data[0] | 0x4;
52 	msg->rsp[1] = msg->data[1];
53 	msg->rsp[2] = completion_code;
54 	msg->rsp_size = 3;
55 	ipmi_smi_msg_received(smi->intf, msg);
56 }
57 
58 static void ipmi_powernv_send(void *send_info, struct ipmi_smi_msg *msg)
59 {
60 	struct ipmi_smi_powernv *smi = send_info;
61 	struct opal_ipmi_msg *opal_msg;
62 	unsigned long flags;
63 	int comp, rc;
64 	size_t size;
65 
66 	/* ensure data_len will fit in the opal_ipmi_msg buffer... */
67 	if (msg->data_size > IPMI_MAX_MSG_LENGTH) {
68 		comp = IPMI_REQ_LEN_EXCEEDED_ERR;
69 		goto err;
70 	}
71 
72 	/* ... and that we at least have netfn and cmd bytes */
73 	if (msg->data_size < 2) {
74 		comp = IPMI_REQ_LEN_INVALID_ERR;
75 		goto err;
76 	}
77 
78 	spin_lock_irqsave(&smi->msg_lock, flags);
79 
80 	if (smi->cur_msg) {
81 		comp = IPMI_NODE_BUSY_ERR;
82 		goto err_unlock;
83 	}
84 
85 	/* format our data for the OPAL API */
86 	opal_msg = smi->opal_msg;
87 	opal_msg->version = OPAL_IPMI_MSG_FORMAT_VERSION_1;
88 	opal_msg->netfn = msg->data[0];
89 	opal_msg->cmd = msg->data[1];
90 	if (msg->data_size > 2)
91 		memcpy(opal_msg->data, msg->data + 2, msg->data_size - 2);
92 
93 	/* data_size already includes the netfn and cmd bytes */
94 	size = sizeof(*opal_msg) + msg->data_size - 2;
95 
96 	pr_devel("%s: opal_ipmi_send(0x%llx, %p, %ld)\n", __func__,
97 			smi->interface_id, opal_msg, size);
98 	rc = opal_ipmi_send(smi->interface_id, opal_msg, size);
99 	pr_devel("%s:  -> %d\n", __func__, rc);
100 
101 	if (!rc) {
102 		smi->cur_msg = msg;
103 		spin_unlock_irqrestore(&smi->msg_lock, flags);
104 		return;
105 	}
106 
107 	comp = IPMI_ERR_UNSPECIFIED;
108 err_unlock:
109 	spin_unlock_irqrestore(&smi->msg_lock, flags);
110 err:
111 	send_error_reply(smi, msg, comp);
112 }
113 
114 static int ipmi_powernv_recv(struct ipmi_smi_powernv *smi)
115 {
116 	struct opal_ipmi_msg *opal_msg;
117 	struct ipmi_smi_msg *msg;
118 	unsigned long flags;
119 	uint64_t size;
120 	int rc;
121 
122 	pr_devel("%s: opal_ipmi_recv(%llx, msg, sz)\n", __func__,
123 			smi->interface_id);
124 
125 	spin_lock_irqsave(&smi->msg_lock, flags);
126 
127 	if (!smi->cur_msg) {
128 		pr_warn("no current message?\n");
129 		return 0;
130 	}
131 
132 	msg = smi->cur_msg;
133 	opal_msg = smi->opal_msg;
134 
135 	size = cpu_to_be64(sizeof(*opal_msg) + IPMI_MAX_MSG_LENGTH);
136 
137 	rc = opal_ipmi_recv(smi->interface_id,
138 			opal_msg,
139 			&size);
140 	size = be64_to_cpu(size);
141 	pr_devel("%s:   -> %d (size %lld)\n", __func__,
142 			rc, rc == 0 ? size : 0);
143 	if (rc) {
144 		spin_unlock_irqrestore(&smi->msg_lock, flags);
145 		ipmi_free_smi_msg(msg);
146 		return 0;
147 	}
148 
149 	if (size < sizeof(*opal_msg)) {
150 		spin_unlock_irqrestore(&smi->msg_lock, flags);
151 		pr_warn("unexpected IPMI message size %lld\n", size);
152 		return 0;
153 	}
154 
155 	if (opal_msg->version != OPAL_IPMI_MSG_FORMAT_VERSION_1) {
156 		spin_unlock_irqrestore(&smi->msg_lock, flags);
157 		pr_warn("unexpected IPMI message format (version %d)\n",
158 				opal_msg->version);
159 		return 0;
160 	}
161 
162 	msg->rsp[0] = opal_msg->netfn;
163 	msg->rsp[1] = opal_msg->cmd;
164 	if (size > sizeof(*opal_msg))
165 		memcpy(&msg->rsp[2], opal_msg->data, size - sizeof(*opal_msg));
166 	msg->rsp_size = 2 + size - sizeof(*opal_msg);
167 
168 	smi->cur_msg = NULL;
169 	spin_unlock_irqrestore(&smi->msg_lock, flags);
170 	ipmi_smi_msg_received(smi->intf, msg);
171 	return 0;
172 }
173 
174 static void ipmi_powernv_request_events(void *send_info)
175 {
176 }
177 
178 static void ipmi_powernv_set_run_to_completion(void *send_info,
179 		bool run_to_completion)
180 {
181 }
182 
183 static void ipmi_powernv_poll(void *send_info)
184 {
185 	struct ipmi_smi_powernv *smi = send_info;
186 
187 	ipmi_powernv_recv(smi);
188 }
189 
190 static struct ipmi_smi_handlers ipmi_powernv_smi_handlers = {
191 	.owner			= THIS_MODULE,
192 	.start_processing	= ipmi_powernv_start_processing,
193 	.sender			= ipmi_powernv_send,
194 	.request_events		= ipmi_powernv_request_events,
195 	.set_run_to_completion	= ipmi_powernv_set_run_to_completion,
196 	.poll			= ipmi_powernv_poll,
197 };
198 
199 static int ipmi_opal_event(struct notifier_block *nb,
200 			  unsigned long events, void *change)
201 {
202 	struct ipmi_smi_powernv *smi = container_of(nb,
203 					struct ipmi_smi_powernv, event_nb);
204 
205 	if (events & smi->event)
206 		ipmi_powernv_recv(smi);
207 	return 0;
208 }
209 
210 static int ipmi_powernv_probe(struct platform_device *pdev)
211 {
212 	struct ipmi_smi_powernv *ipmi;
213 	struct device *dev;
214 	u32 prop;
215 	int rc;
216 
217 	if (!pdev || !pdev->dev.of_node)
218 		return -ENODEV;
219 
220 	dev = &pdev->dev;
221 
222 	ipmi = devm_kzalloc(dev, sizeof(*ipmi), GFP_KERNEL);
223 	if (!ipmi)
224 		return -ENOMEM;
225 
226 	spin_lock_init(&ipmi->msg_lock);
227 
228 	rc = of_property_read_u32(dev->of_node, "ibm,ipmi-interface-id",
229 			&prop);
230 	if (rc) {
231 		dev_warn(dev, "No interface ID property\n");
232 		goto err_free;
233 	}
234 	ipmi->interface_id = prop;
235 
236 	rc = of_property_read_u32(dev->of_node, "interrupts", &prop);
237 	if (rc) {
238 		dev_warn(dev, "No interrupts property\n");
239 		goto err_free;
240 	}
241 
242 	ipmi->event = 1ull << prop;
243 	ipmi->event_nb.notifier_call = ipmi_opal_event;
244 
245 	rc = opal_notifier_register(&ipmi->event_nb);
246 	if (rc) {
247 		dev_warn(dev, "OPAL notifier registration failed (%d)\n", rc);
248 		goto err_free;
249 	}
250 
251 	ipmi->opal_msg = devm_kmalloc(dev,
252 			sizeof(*ipmi->opal_msg) + IPMI_MAX_MSG_LENGTH,
253 			GFP_KERNEL);
254 	if (!ipmi->opal_msg) {
255 		rc = -ENOMEM;
256 		goto err_unregister;
257 	}
258 
259 	/* todo: query actual ipmi_device_id */
260 	rc = ipmi_register_smi(&ipmi_powernv_smi_handlers, ipmi,
261 			&ipmi->ipmi_id, dev, 0);
262 	if (rc) {
263 		dev_warn(dev, "IPMI SMI registration failed (%d)\n", rc);
264 		goto err_free_msg;
265 	}
266 
267 	dev_set_drvdata(dev, ipmi);
268 	return 0;
269 
270 err_free_msg:
271 	devm_kfree(dev, ipmi->opal_msg);
272 err_unregister:
273 	opal_notifier_unregister(&ipmi->event_nb);
274 err_free:
275 	devm_kfree(dev, ipmi);
276 	return rc;
277 }
278 
279 static int ipmi_powernv_remove(struct platform_device *pdev)
280 {
281 	struct ipmi_smi_powernv *smi = dev_get_drvdata(&pdev->dev);
282 
283 	ipmi_unregister_smi(smi->intf);
284 	opal_notifier_unregister(&smi->event_nb);
285 	return 0;
286 }
287 
288 static const struct of_device_id ipmi_powernv_match[] = {
289 	{ .compatible = "ibm,opal-ipmi" },
290 	{ },
291 };
292 
293 
294 static struct platform_driver powernv_ipmi_driver = {
295 	.driver = {
296 		.name		= "ipmi-powernv",
297 		.owner		= THIS_MODULE,
298 		.of_match_table	= ipmi_powernv_match,
299 	},
300 	.probe	= ipmi_powernv_probe,
301 	.remove	= ipmi_powernv_remove,
302 };
303 
304 
305 module_platform_driver(powernv_ipmi_driver);
306 
307 MODULE_DEVICE_TABLE(of, ipmi_powernv_match);
308 MODULE_DESCRIPTION("powernv IPMI driver");
309 MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");
310 MODULE_LICENSE("GPL");
311