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
20struct 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
36static 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
44static 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
54static 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;
104err_unlock:
105	spin_unlock_irqrestore(&smi->msg_lock, flags);
106err:
107	send_error_reply(smi, msg, comp);
108}
109
110static 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
178static void ipmi_powernv_request_events(void *send_info)
179{
180}
181
182static void ipmi_powernv_set_run_to_completion(void *send_info,
183		bool run_to_completion)
184{
185}
186
187static void ipmi_powernv_poll(void *send_info)
188{
189	struct ipmi_smi_powernv *smi = send_info;
190
191	ipmi_powernv_recv(smi);
192}
193
194static 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
203static 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
211static 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
273err_free_msg:
274	devm_kfree(dev, ipmi->opal_msg);
275err_unregister:
276	free_irq(ipmi->irq, ipmi);
277err_dispose:
278	irq_dispose_mapping(ipmi->irq);
279err_free:
280	devm_kfree(dev, ipmi);
281	return rc;
282}
283
284static 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
295static const struct of_device_id ipmi_powernv_match[] = {
296	{ .compatible = "ibm,opal-ipmi" },
297	{ },
298};
299
300
301static 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
311module_platform_driver(powernv_ipmi_driver);
312
313MODULE_DEVICE_TABLE(of, ipmi_powernv_match);
314MODULE_DESCRIPTION("powernv IPMI driver");
315MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");
316MODULE_LICENSE("GPL");
317