1/*
2 * SN Platform system controller communication support
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License.  See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (C) 2004-2006 Silicon Graphics, Inc. All rights reserved.
9 */
10
11/*
12 * System controller event handler
13 *
14 * These routines deal with environmental events arriving from the
15 * system controllers.
16 */
17
18#include <linux/interrupt.h>
19#include <linux/sched.h>
20#include <linux/slab.h>
21#include <asm/byteorder.h>
22#include <asm/sn/sn_sal.h>
23#include <asm/unaligned.h>
24#include "snsc.h"
25
26static struct subch_data_s *event_sd;
27
28void scdrv_event(unsigned long);
29DECLARE_TASKLET(sn_sysctl_event, scdrv_event, 0);
30
31/*
32 * scdrv_event_interrupt
33 *
34 * Pull incoming environmental events off the physical link to the
35 * system controller and put them in a temporary holding area in SAL.
36 * Schedule scdrv_event() to move them along to their ultimate
37 * destination.
38 */
39static irqreturn_t
40scdrv_event_interrupt(int irq, void *subch_data)
41{
42	struct subch_data_s *sd = subch_data;
43	unsigned long flags;
44	int status;
45
46	spin_lock_irqsave(&sd->sd_rlock, flags);
47	status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch);
48
49	if ((status > 0) && (status & SAL_IROUTER_INTR_RECV)) {
50		tasklet_schedule(&sn_sysctl_event);
51	}
52	spin_unlock_irqrestore(&sd->sd_rlock, flags);
53	return IRQ_HANDLED;
54}
55
56
57/*
58 * scdrv_parse_event
59 *
60 * Break an event (as read from SAL) into useful pieces so we can decide
61 * what to do with it.
62 */
63static int
64scdrv_parse_event(char *event, int *src, int *code, int *esp_code, char *desc)
65{
66	char *desc_end;
67
68	/* record event source address */
69	*src = get_unaligned_be32(event);
70	event += 4; 			/* move on to event code */
71
72	/* record the system controller's event code */
73	*code = get_unaligned_be32(event);
74	event += 4;			/* move on to event arguments */
75
76	/* how many arguments are in the packet? */
77	if (*event++ != 2) {
78		/* if not 2, give up */
79		return -1;
80	}
81
82	/* parse out the ESP code */
83	if (*event++ != IR_ARG_INT) {
84		/* not an integer argument, so give up */
85		return -1;
86	}
87	*esp_code = get_unaligned_be32(event);
88	event += 4;
89
90	/* parse out the event description */
91	if (*event++ != IR_ARG_ASCII) {
92		/* not an ASCII string, so give up */
93		return -1;
94	}
95	event[CHUNKSIZE-1] = '\0';	/* ensure this string ends! */
96	event += 2; 			/* skip leading CR/LF */
97	desc_end = desc + sprintf(desc, "%s", event);
98
99	/* strip trailing CR/LF (if any) */
100	for (desc_end--;
101	     (desc_end != desc) && ((*desc_end == 0xd) || (*desc_end == 0xa));
102	     desc_end--) {
103		*desc_end = '\0';
104	}
105
106	return 0;
107}
108
109
110/*
111 * scdrv_event_severity
112 *
113 * Figure out how urgent a message we should write to the console/syslog
114 * via printk.
115 */
116static char *
117scdrv_event_severity(int code)
118{
119	int ev_class = (code & EV_CLASS_MASK);
120	int ev_severity = (code & EV_SEVERITY_MASK);
121	char *pk_severity = KERN_NOTICE;
122
123	switch (ev_class) {
124	case EV_CLASS_POWER:
125		switch (ev_severity) {
126		case EV_SEVERITY_POWER_LOW_WARNING:
127		case EV_SEVERITY_POWER_HIGH_WARNING:
128			pk_severity = KERN_WARNING;
129			break;
130		case EV_SEVERITY_POWER_HIGH_FAULT:
131		case EV_SEVERITY_POWER_LOW_FAULT:
132			pk_severity = KERN_ALERT;
133			break;
134		}
135		break;
136	case EV_CLASS_FAN:
137		switch (ev_severity) {
138		case EV_SEVERITY_FAN_WARNING:
139			pk_severity = KERN_WARNING;
140			break;
141		case EV_SEVERITY_FAN_FAULT:
142			pk_severity = KERN_CRIT;
143			break;
144		}
145		break;
146	case EV_CLASS_TEMP:
147		switch (ev_severity) {
148		case EV_SEVERITY_TEMP_ADVISORY:
149			pk_severity = KERN_WARNING;
150			break;
151		case EV_SEVERITY_TEMP_CRITICAL:
152			pk_severity = KERN_CRIT;
153			break;
154		case EV_SEVERITY_TEMP_FAULT:
155			pk_severity = KERN_ALERT;
156			break;
157		}
158		break;
159	case EV_CLASS_ENV:
160		pk_severity = KERN_ALERT;
161		break;
162	case EV_CLASS_TEST_FAULT:
163		pk_severity = KERN_ALERT;
164		break;
165	case EV_CLASS_TEST_WARNING:
166		pk_severity = KERN_WARNING;
167		break;
168	case EV_CLASS_PWRD_NOTIFY:
169		pk_severity = KERN_ALERT;
170		break;
171	}
172
173	return pk_severity;
174}
175
176
177/*
178 * scdrv_dispatch_event
179 *
180 * Do the right thing with an incoming event.  That's often nothing
181 * more than printing it to the system log.  For power-down notifications
182 * we start a graceful shutdown.
183 */
184static void
185scdrv_dispatch_event(char *event, int len)
186{
187	static int snsc_shutting_down = 0;
188	int code, esp_code, src, class;
189	char desc[CHUNKSIZE];
190	char *severity;
191
192	if (scdrv_parse_event(event, &src, &code, &esp_code, desc) < 0) {
193		/* ignore uninterpretible event */
194		return;
195	}
196
197	/* how urgent is the message? */
198	severity = scdrv_event_severity(code);
199
200	class = (code & EV_CLASS_MASK);
201
202	if (class == EV_CLASS_PWRD_NOTIFY || code == ENV_PWRDN_PEND) {
203		if (snsc_shutting_down)
204			return;
205
206		snsc_shutting_down = 1;
207
208		/* give a message for each type of event */
209		if (class == EV_CLASS_PWRD_NOTIFY)
210			printk(KERN_NOTICE "Power off indication received."
211			       " Sending SIGPWR to init...\n");
212		else if (code == ENV_PWRDN_PEND)
213			printk(KERN_CRIT "WARNING: Shutting down the system"
214			       " due to a critical environmental condition."
215			       " Sending SIGPWR to init...\n");
216
217		/* give a SIGPWR signal to init proc */
218		kill_cad_pid(SIGPWR, 0);
219	} else {
220		/* print to system log */
221		printk("%s|$(0x%x)%s\n", severity, esp_code, desc);
222	}
223}
224
225
226/*
227 * scdrv_event
228 *
229 * Called as a tasklet when an event arrives from the L1.  Read the event
230 * from where it's temporarily stored in SAL and call scdrv_dispatch_event()
231 * to send it on its way.  Keep trying to read events until SAL indicates
232 * that there are no more immediately available.
233 */
234void
235scdrv_event(unsigned long dummy)
236{
237	int status;
238	int len;
239	unsigned long flags;
240	struct subch_data_s *sd = event_sd;
241
242	/* anything to read? */
243	len = CHUNKSIZE;
244	spin_lock_irqsave(&sd->sd_rlock, flags);
245	status = ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch,
246				   sd->sd_rb, &len);
247
248	while (!(status < 0)) {
249		spin_unlock_irqrestore(&sd->sd_rlock, flags);
250		scdrv_dispatch_event(sd->sd_rb, len);
251		len = CHUNKSIZE;
252		spin_lock_irqsave(&sd->sd_rlock, flags);
253		status = ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch,
254					   sd->sd_rb, &len);
255	}
256	spin_unlock_irqrestore(&sd->sd_rlock, flags);
257}
258
259
260/*
261 * scdrv_event_init
262 *
263 * Sets up a system controller subchannel to begin receiving event
264 * messages. This is sort of a specialized version of scdrv_open()
265 * in drivers/char/sn_sysctl.c.
266 */
267void
268scdrv_event_init(struct sysctl_data_s *scd)
269{
270	int rv;
271
272	event_sd = kzalloc(sizeof (struct subch_data_s), GFP_KERNEL);
273	if (event_sd == NULL) {
274		printk(KERN_WARNING "%s: couldn't allocate subchannel info"
275		       " for event monitoring\n", __func__);
276		return;
277	}
278
279	/* initialize subch_data_s fields */
280	event_sd->sd_nasid = scd->scd_nasid;
281	spin_lock_init(&event_sd->sd_rlock);
282
283	/* ask the system controllers to send events to this node */
284	event_sd->sd_subch = ia64_sn_sysctl_event_init(scd->scd_nasid);
285
286	if (event_sd->sd_subch < 0) {
287		kfree(event_sd);
288		printk(KERN_WARNING "%s: couldn't open event subchannel\n",
289		       __func__);
290		return;
291	}
292
293	/* hook event subchannel up to the system controller interrupt */
294	rv = request_irq(SGI_UART_VECTOR, scdrv_event_interrupt,
295			 IRQF_SHARED, "system controller events", event_sd);
296	if (rv) {
297		printk(KERN_WARNING "%s: irq request failed (%d)\n",
298		       __func__, rv);
299		ia64_sn_irtr_close(event_sd->sd_nasid, event_sd->sd_subch);
300		kfree(event_sd);
301		return;
302	}
303}
304