1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * PowerNV OPAL IPMI driver
4  *
5  * Copyright 2014 IBM Corp.
6  */
7 
8 #define pr_fmt(fmt)        "ipmi-powernv: " fmt
9 
10 #include <linux/ipmi_smi.h>
11 #include <linux/list.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_irq.h>
15 #include <linux/interrupt.h>
16 
17 #include <asm/opal.h>
18 
19 
20 struct ipmi_smi_powernv {
21 	u64			interface_id;
22 	struct ipmi_smi		*intf;
23 	unsigned int		irq;
24 
25 	/**
26 	 * We assume that there can only be one outstanding request, so
27 	 * keep the pending message in cur_msg. We protect this from concurrent
28 	 * updates through send & recv calls, (and consequently opal_msg, which
29 	 * is in-use when cur_msg is set) with msg_lock
30 	 */
31 	spinlock_t		msg_lock;
32 	struct ipmi_smi_msg	*cur_msg;
33 	struct opal_ipmi_msg	*opal_msg;
34 };
35 
ipmi_powernv_start_processing(void * send_info,struct ipmi_smi * intf)36 static int ipmi_powernv_start_processing(void *send_info, struct ipmi_smi *intf)
37 {
38 	struct ipmi_smi_powernv *smi = send_info;
39 
40 	smi->intf = intf;
41 	return 0;
42 }
43 
send_error_reply(struct ipmi_smi_powernv * smi,struct ipmi_smi_msg * msg,u8 completion_code)44 static void send_error_reply(struct ipmi_smi_powernv *smi,
45 		struct ipmi_smi_msg *msg, u8 completion_code)
46 {
47 	msg->rsp[0] = msg->data[0] | 0x4;
48 	msg->rsp[1] = msg->data[1];
49 	msg->rsp[2] = completion_code;
50 	msg->rsp_size = 3;
51 	ipmi_smi_msg_received(smi->intf, msg);
52 }
53 
ipmi_powernv_send(void * send_info,struct ipmi_smi_msg * msg)54 static void ipmi_powernv_send(void *send_info, struct ipmi_smi_msg *msg)
55 {
56 	struct ipmi_smi_powernv *smi = send_info;
57 	struct opal_ipmi_msg *opal_msg;
58 	unsigned long flags;
59 	int comp, rc;
60 	size_t size;
61 
62 	/* ensure data_len will fit in the opal_ipmi_msg buffer... */
63 	if (msg->data_size > IPMI_MAX_MSG_LENGTH) {
64 		comp = IPMI_REQ_LEN_EXCEEDED_ERR;
65 		goto err;
66 	}
67 
68 	/* ... and that we at least have netfn and cmd bytes */
69 	if (msg->data_size < 2) {
70 		comp = IPMI_REQ_LEN_INVALID_ERR;
71 		goto err;
72 	}
73 
74 	spin_lock_irqsave(&smi->msg_lock, flags);
75 
76 	if (smi->cur_msg) {
77 		comp = IPMI_NODE_BUSY_ERR;
78 		goto err_unlock;
79 	}
80 
81 	/* format our data for the OPAL API */
82 	opal_msg = smi->opal_msg;
83 	opal_msg->version = OPAL_IPMI_MSG_FORMAT_VERSION_1;
84 	opal_msg->netfn = msg->data[0];
85 	opal_msg->cmd = msg->data[1];
86 	if (msg->data_size > 2)
87 		memcpy(opal_msg->data, msg->data + 2, msg->data_size - 2);
88 
89 	/* data_size already includes the netfn and cmd bytes */
90 	size = sizeof(*opal_msg) + msg->data_size - 2;
91 
92 	pr_devel("%s: opal_ipmi_send(0x%llx, %p, %ld)\n", __func__,
93 			smi->interface_id, opal_msg, size);
94 	rc = opal_ipmi_send(smi->interface_id, opal_msg, size);
95 	pr_devel("%s:  -> %d\n", __func__, rc);
96 
97 	if (!rc) {
98 		smi->cur_msg = msg;
99 		spin_unlock_irqrestore(&smi->msg_lock, flags);
100 		return;
101 	}
102 
103 	comp = IPMI_ERR_UNSPECIFIED;
104 err_unlock:
105 	spin_unlock_irqrestore(&smi->msg_lock, flags);
106 err:
107 	send_error_reply(smi, msg, comp);
108 }
109 
ipmi_powernv_recv(struct ipmi_smi_powernv * smi)110 static int ipmi_powernv_recv(struct ipmi_smi_powernv *smi)
111 {
112 	struct opal_ipmi_msg *opal_msg;
113 	struct ipmi_smi_msg *msg;
114 	unsigned long flags;
115 	uint64_t size;
116 	int rc;
117 
118 	pr_devel("%s: opal_ipmi_recv(%llx, msg, sz)\n", __func__,
119 			smi->interface_id);
120 
121 	spin_lock_irqsave(&smi->msg_lock, flags);
122 
123 	if (!smi->cur_msg) {
124 		spin_unlock_irqrestore(&smi->msg_lock, flags);
125 		pr_warn("no current message?\n");
126 		return 0;
127 	}
128 
129 	msg = smi->cur_msg;
130 	opal_msg = smi->opal_msg;
131 
132 	size = cpu_to_be64(sizeof(*opal_msg) + IPMI_MAX_MSG_LENGTH);
133 
134 	rc = opal_ipmi_recv(smi->interface_id,
135 			opal_msg,
136 			&size);
137 	size = be64_to_cpu(size);
138 	pr_devel("%s:   -> %d (size %lld)\n", __func__,
139 			rc, rc == 0 ? size : 0);
140 	if (rc) {
141 		/* If came via the poll, and response was not yet ready */
142 		if (rc == OPAL_EMPTY) {
143 			spin_unlock_irqrestore(&smi->msg_lock, flags);
144 			return 0;
145 		}
146 
147 		smi->cur_msg = NULL;
148 		spin_unlock_irqrestore(&smi->msg_lock, flags);
149 		send_error_reply(smi, msg, IPMI_ERR_UNSPECIFIED);
150 		return 0;
151 	}
152 
153 	if (size < sizeof(*opal_msg)) {
154 		spin_unlock_irqrestore(&smi->msg_lock, flags);
155 		pr_warn("unexpected IPMI message size %lld\n", size);
156 		return 0;
157 	}
158 
159 	if (opal_msg->version != OPAL_IPMI_MSG_FORMAT_VERSION_1) {
160 		spin_unlock_irqrestore(&smi->msg_lock, flags);
161 		pr_warn("unexpected IPMI message format (version %d)\n",
162 				opal_msg->version);
163 		return 0;
164 	}
165 
166 	msg->rsp[0] = opal_msg->netfn;
167 	msg->rsp[1] = opal_msg->cmd;
168 	if (size > sizeof(*opal_msg))
169 		memcpy(&msg->rsp[2], opal_msg->data, size - sizeof(*opal_msg));
170 	msg->rsp_size = 2 + size - sizeof(*opal_msg);
171 
172 	smi->cur_msg = NULL;
173 	spin_unlock_irqrestore(&smi->msg_lock, flags);
174 	ipmi_smi_msg_received(smi->intf, msg);
175 	return 0;
176 }
177 
ipmi_powernv_request_events(void * send_info)178 static void ipmi_powernv_request_events(void *send_info)
179 {
180 }
181 
ipmi_powernv_set_run_to_completion(void * send_info,bool run_to_completion)182 static void ipmi_powernv_set_run_to_completion(void *send_info,
183 		bool run_to_completion)
184 {
185 }
186 
ipmi_powernv_poll(void * send_info)187 static void ipmi_powernv_poll(void *send_info)
188 {
189 	struct ipmi_smi_powernv *smi = send_info;
190 
191 	ipmi_powernv_recv(smi);
192 }
193 
194 static const struct ipmi_smi_handlers ipmi_powernv_smi_handlers = {
195 	.owner			= THIS_MODULE,
196 	.start_processing	= ipmi_powernv_start_processing,
197 	.sender			= ipmi_powernv_send,
198 	.request_events		= ipmi_powernv_request_events,
199 	.set_run_to_completion	= ipmi_powernv_set_run_to_completion,
200 	.poll			= ipmi_powernv_poll,
201 };
202 
ipmi_opal_event(int irq,void * data)203 static irqreturn_t ipmi_opal_event(int irq, void *data)
204 {
205 	struct ipmi_smi_powernv *smi = data;
206 
207 	ipmi_powernv_recv(smi);
208 	return IRQ_HANDLED;
209 }
210 
ipmi_powernv_probe(struct platform_device * pdev)211 static int ipmi_powernv_probe(struct platform_device *pdev)
212 {
213 	struct ipmi_smi_powernv *ipmi;
214 	struct device *dev;
215 	u32 prop;
216 	int rc;
217 
218 	if (!pdev || !pdev->dev.of_node)
219 		return -ENODEV;
220 
221 	dev = &pdev->dev;
222 
223 	ipmi = devm_kzalloc(dev, sizeof(*ipmi), GFP_KERNEL);
224 	if (!ipmi)
225 		return -ENOMEM;
226 
227 	spin_lock_init(&ipmi->msg_lock);
228 
229 	rc = of_property_read_u32(dev->of_node, "ibm,ipmi-interface-id",
230 			&prop);
231 	if (rc) {
232 		dev_warn(dev, "No interface ID property\n");
233 		goto err_free;
234 	}
235 	ipmi->interface_id = prop;
236 
237 	rc = of_property_read_u32(dev->of_node, "interrupts", &prop);
238 	if (rc) {
239 		dev_warn(dev, "No interrupts property\n");
240 		goto err_free;
241 	}
242 
243 	ipmi->irq = irq_of_parse_and_map(dev->of_node, 0);
244 	if (!ipmi->irq) {
245 		dev_info(dev, "Unable to map irq from device tree\n");
246 		ipmi->irq = opal_event_request(prop);
247 	}
248 
249 	rc = request_irq(ipmi->irq, ipmi_opal_event, IRQ_TYPE_LEVEL_HIGH,
250 			 "opal-ipmi", ipmi);
251 	if (rc) {
252 		dev_warn(dev, "Unable to request irq\n");
253 		goto err_dispose;
254 	}
255 
256 	ipmi->opal_msg = devm_kmalloc(dev,
257 			sizeof(*ipmi->opal_msg) + IPMI_MAX_MSG_LENGTH,
258 			GFP_KERNEL);
259 	if (!ipmi->opal_msg) {
260 		rc = -ENOMEM;
261 		goto err_unregister;
262 	}
263 
264 	rc = ipmi_register_smi(&ipmi_powernv_smi_handlers, ipmi, dev, 0);
265 	if (rc) {
266 		dev_warn(dev, "IPMI SMI registration failed (%d)\n", rc);
267 		goto err_free_msg;
268 	}
269 
270 	dev_set_drvdata(dev, ipmi);
271 	return 0;
272 
273 err_free_msg:
274 	devm_kfree(dev, ipmi->opal_msg);
275 err_unregister:
276 	free_irq(ipmi->irq, ipmi);
277 err_dispose:
278 	irq_dispose_mapping(ipmi->irq);
279 err_free:
280 	devm_kfree(dev, ipmi);
281 	return rc;
282 }
283 
ipmi_powernv_remove(struct platform_device * pdev)284 static int ipmi_powernv_remove(struct platform_device *pdev)
285 {
286 	struct ipmi_smi_powernv *smi = dev_get_drvdata(&pdev->dev);
287 
288 	ipmi_unregister_smi(smi->intf);
289 	free_irq(smi->irq, smi);
290 	irq_dispose_mapping(smi->irq);
291 
292 	return 0;
293 }
294 
295 static const struct of_device_id ipmi_powernv_match[] = {
296 	{ .compatible = "ibm,opal-ipmi" },
297 	{ },
298 };
299 
300 
301 static struct platform_driver powernv_ipmi_driver = {
302 	.driver = {
303 		.name		= "ipmi-powernv",
304 		.of_match_table	= ipmi_powernv_match,
305 	},
306 	.probe	= ipmi_powernv_probe,
307 	.remove	= ipmi_powernv_remove,
308 };
309 
310 
311 module_platform_driver(powernv_ipmi_driver);
312 
313 MODULE_DEVICE_TABLE(of, ipmi_powernv_match);
314 MODULE_DESCRIPTION("powernv IPMI driver");
315 MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");
316 MODULE_LICENSE("GPL");
317