ia64/linux-2.6.18-xen.hg

view drivers/char/snsc_event.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
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 */
11 /*
12 * System controller event handler
13 *
14 * These routines deal with environmental events arriving from the
15 * system controllers.
16 */
18 #include <linux/interrupt.h>
19 #include <linux/sched.h>
20 #include <linux/byteorder/generic.h>
21 #include <asm/sn/sn_sal.h>
22 #include <asm/unaligned.h>
23 #include "snsc.h"
25 static struct subch_data_s *event_sd;
27 void scdrv_event(unsigned long);
28 DECLARE_TASKLET(sn_sysctl_event, scdrv_event, 0);
30 /*
31 * scdrv_event_interrupt
32 *
33 * Pull incoming environmental events off the physical link to the
34 * system controller and put them in a temporary holding area in SAL.
35 * Schedule scdrv_event() to move them along to their ultimate
36 * destination.
37 */
38 static irqreturn_t
39 scdrv_event_interrupt(int irq, void *subch_data, struct pt_regs *regs)
40 {
41 struct subch_data_s *sd = subch_data;
42 unsigned long flags;
43 int status;
45 spin_lock_irqsave(&sd->sd_rlock, flags);
46 status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch);
48 if ((status > 0) && (status & SAL_IROUTER_INTR_RECV)) {
49 tasklet_schedule(&sn_sysctl_event);
50 }
51 spin_unlock_irqrestore(&sd->sd_rlock, flags);
52 return IRQ_HANDLED;
53 }
56 /*
57 * scdrv_parse_event
58 *
59 * Break an event (as read from SAL) into useful pieces so we can decide
60 * what to do with it.
61 */
62 static int
63 scdrv_parse_event(char *event, int *src, int *code, int *esp_code, char *desc)
64 {
65 char *desc_end;
66 __be32 from_buf;
68 /* record event source address */
69 from_buf = get_unaligned((__be32 *)event);
70 *src = be32_to_cpup(&from_buf);
71 event += 4; /* move on to event code */
73 /* record the system controller's event code */
74 from_buf = get_unaligned((__be32 *)event);
75 *code = be32_to_cpup(&from_buf);
76 event += 4; /* move on to event arguments */
78 /* how many arguments are in the packet? */
79 if (*event++ != 2) {
80 /* if not 2, give up */
81 return -1;
82 }
84 /* parse out the ESP code */
85 if (*event++ != IR_ARG_INT) {
86 /* not an integer argument, so give up */
87 return -1;
88 }
89 from_buf = get_unaligned((__be32 *)event);
90 *esp_code = be32_to_cpup(&from_buf);
91 event += 4;
93 /* parse out the event description */
94 if (*event++ != IR_ARG_ASCII) {
95 /* not an ASCII string, so give up */
96 return -1;
97 }
98 event[CHUNKSIZE-1] = '\0'; /* ensure this string ends! */
99 event += 2; /* skip leading CR/LF */
100 desc_end = desc + sprintf(desc, "%s", event);
102 /* strip trailing CR/LF (if any) */
103 for (desc_end--;
104 (desc_end != desc) && ((*desc_end == 0xd) || (*desc_end == 0xa));
105 desc_end--) {
106 *desc_end = '\0';
107 }
109 return 0;
110 }
113 /*
114 * scdrv_event_severity
115 *
116 * Figure out how urgent a message we should write to the console/syslog
117 * via printk.
118 */
119 static char *
120 scdrv_event_severity(int code)
121 {
122 int ev_class = (code & EV_CLASS_MASK);
123 int ev_severity = (code & EV_SEVERITY_MASK);
124 char *pk_severity = KERN_NOTICE;
126 switch (ev_class) {
127 case EV_CLASS_POWER:
128 switch (ev_severity) {
129 case EV_SEVERITY_POWER_LOW_WARNING:
130 case EV_SEVERITY_POWER_HIGH_WARNING:
131 pk_severity = KERN_WARNING;
132 break;
133 case EV_SEVERITY_POWER_HIGH_FAULT:
134 case EV_SEVERITY_POWER_LOW_FAULT:
135 pk_severity = KERN_ALERT;
136 break;
137 }
138 break;
139 case EV_CLASS_FAN:
140 switch (ev_severity) {
141 case EV_SEVERITY_FAN_WARNING:
142 pk_severity = KERN_WARNING;
143 break;
144 case EV_SEVERITY_FAN_FAULT:
145 pk_severity = KERN_CRIT;
146 break;
147 }
148 break;
149 case EV_CLASS_TEMP:
150 switch (ev_severity) {
151 case EV_SEVERITY_TEMP_ADVISORY:
152 pk_severity = KERN_WARNING;
153 break;
154 case EV_SEVERITY_TEMP_CRITICAL:
155 pk_severity = KERN_CRIT;
156 break;
157 case EV_SEVERITY_TEMP_FAULT:
158 pk_severity = KERN_ALERT;
159 break;
160 }
161 break;
162 case EV_CLASS_ENV:
163 pk_severity = KERN_ALERT;
164 break;
165 case EV_CLASS_TEST_FAULT:
166 pk_severity = KERN_ALERT;
167 break;
168 case EV_CLASS_TEST_WARNING:
169 pk_severity = KERN_WARNING;
170 break;
171 case EV_CLASS_PWRD_NOTIFY:
172 pk_severity = KERN_ALERT;
173 break;
174 }
176 return pk_severity;
177 }
180 /*
181 * scdrv_dispatch_event
182 *
183 * Do the right thing with an incoming event. That's often nothing
184 * more than printing it to the system log. For power-down notifications
185 * we start a graceful shutdown.
186 */
187 static void
188 scdrv_dispatch_event(char *event, int len)
189 {
190 static int snsc_shutting_down = 0;
191 int code, esp_code, src, class;
192 char desc[CHUNKSIZE];
193 char *severity;
195 if (scdrv_parse_event(event, &src, &code, &esp_code, desc) < 0) {
196 /* ignore uninterpretible event */
197 return;
198 }
200 /* how urgent is the message? */
201 severity = scdrv_event_severity(code);
203 class = (code & EV_CLASS_MASK);
205 if (class == EV_CLASS_PWRD_NOTIFY || code == ENV_PWRDN_PEND) {
206 struct task_struct *p;
208 if (snsc_shutting_down)
209 return;
211 snsc_shutting_down = 1;
213 /* give a message for each type of event */
214 if (class == EV_CLASS_PWRD_NOTIFY)
215 printk(KERN_NOTICE "Power off indication received."
216 " Sending SIGPWR to init...\n");
217 else if (code == ENV_PWRDN_PEND)
218 printk(KERN_CRIT "WARNING: Shutting down the system"
219 " due to a critical environmental condition."
220 " Sending SIGPWR to init...\n");
222 /* give a SIGPWR signal to init proc */
223 kill_proc(1, SIGPWR, 0);
224 } else {
225 /* print to system log */
226 printk("%s|$(0x%x)%s\n", severity, esp_code, desc);
227 }
228 }
231 /*
232 * scdrv_event
233 *
234 * Called as a tasklet when an event arrives from the L1. Read the event
235 * from where it's temporarily stored in SAL and call scdrv_dispatch_event()
236 * to send it on its way. Keep trying to read events until SAL indicates
237 * that there are no more immediately available.
238 */
239 void
240 scdrv_event(unsigned long dummy)
241 {
242 int status;
243 int len;
244 unsigned long flags;
245 struct subch_data_s *sd = event_sd;
247 /* anything to read? */
248 len = CHUNKSIZE;
249 spin_lock_irqsave(&sd->sd_rlock, flags);
250 status = ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch,
251 sd->sd_rb, &len);
253 while (!(status < 0)) {
254 spin_unlock_irqrestore(&sd->sd_rlock, flags);
255 scdrv_dispatch_event(sd->sd_rb, len);
256 len = CHUNKSIZE;
257 spin_lock_irqsave(&sd->sd_rlock, flags);
258 status = ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch,
259 sd->sd_rb, &len);
260 }
261 spin_unlock_irqrestore(&sd->sd_rlock, flags);
262 }
265 /*
266 * scdrv_event_init
267 *
268 * Sets up a system controller subchannel to begin receiving event
269 * messages. This is sort of a specialized version of scdrv_open()
270 * in drivers/char/sn_sysctl.c.
271 */
272 void
273 scdrv_event_init(struct sysctl_data_s *scd)
274 {
275 int rv;
277 event_sd = kzalloc(sizeof (struct subch_data_s), GFP_KERNEL);
278 if (event_sd == NULL) {
279 printk(KERN_WARNING "%s: couldn't allocate subchannel info"
280 " for event monitoring\n", __FUNCTION__);
281 return;
282 }
284 /* initialize subch_data_s fields */
285 event_sd->sd_nasid = scd->scd_nasid;
286 spin_lock_init(&event_sd->sd_rlock);
288 /* ask the system controllers to send events to this node */
289 event_sd->sd_subch = ia64_sn_sysctl_event_init(scd->scd_nasid);
291 if (event_sd->sd_subch < 0) {
292 kfree(event_sd);
293 printk(KERN_WARNING "%s: couldn't open event subchannel\n",
294 __FUNCTION__);
295 return;
296 }
298 /* hook event subchannel up to the system controller interrupt */
299 rv = request_irq(SGI_UART_VECTOR, scdrv_event_interrupt,
300 IRQF_SHARED | IRQF_DISABLED,
301 "system controller events", event_sd);
302 if (rv) {
303 printk(KERN_WARNING "%s: irq request failed (%d)\n",
304 __FUNCTION__, rv);
305 ia64_sn_irtr_close(event_sd->sd_nasid, event_sd->sd_subch);
306 kfree(event_sd);
307 return;
308 }
309 }