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9#include <linux/kmod.h>
10#include <linux/console.h>
11#include <linux/init.h>
12#include <linux/timer.h>
13#include <linux/jiffies.h>
14#include <linux/termios.h>
15#include <linux/err.h>
16#include <linux/reboot.h>
17#include <linux/gfp.h>
18
19#include "sclp.h"
20#include "sclp_rw.h"
21#include "sclp_tty.h"
22
23#define sclp_console_major 4
24#define sclp_console_minor 64
25#define sclp_console_name "ttyS"
26
27
28static spinlock_t sclp_con_lock;
29
30static struct list_head sclp_con_pages;
31
32static struct list_head sclp_con_outqueue;
33
34static struct sclp_buffer *sclp_conbuf;
35
36static struct timer_list sclp_con_timer;
37
38static int sclp_con_suspended;
39
40static int sclp_con_queue_running;
41
42
43static unsigned short sclp_con_columns;
44static unsigned short sclp_con_width_htab;
45
46static void
47sclp_conbuf_callback(struct sclp_buffer *buffer, int rc)
48{
49 unsigned long flags;
50 void *page;
51
52 do {
53 page = sclp_unmake_buffer(buffer);
54 spin_lock_irqsave(&sclp_con_lock, flags);
55
56
57 list_del(&buffer->list);
58 list_add_tail((struct list_head *) page, &sclp_con_pages);
59
60
61 buffer = NULL;
62 if (!list_empty(&sclp_con_outqueue))
63 buffer = list_first_entry(&sclp_con_outqueue,
64 struct sclp_buffer, list);
65 if (!buffer || sclp_con_suspended) {
66 sclp_con_queue_running = 0;
67 spin_unlock_irqrestore(&sclp_con_lock, flags);
68 break;
69 }
70 spin_unlock_irqrestore(&sclp_con_lock, flags);
71 } while (sclp_emit_buffer(buffer, sclp_conbuf_callback));
72}
73
74
75
76
77static void sclp_conbuf_emit(void)
78{
79 struct sclp_buffer* buffer;
80 unsigned long flags;
81 int rc;
82
83 spin_lock_irqsave(&sclp_con_lock, flags);
84 if (sclp_conbuf)
85 list_add_tail(&sclp_conbuf->list, &sclp_con_outqueue);
86 sclp_conbuf = NULL;
87 if (sclp_con_queue_running || sclp_con_suspended)
88 goto out_unlock;
89 if (list_empty(&sclp_con_outqueue))
90 goto out_unlock;
91 buffer = list_first_entry(&sclp_con_outqueue, struct sclp_buffer,
92 list);
93 sclp_con_queue_running = 1;
94 spin_unlock_irqrestore(&sclp_con_lock, flags);
95
96 rc = sclp_emit_buffer(buffer, sclp_conbuf_callback);
97 if (rc)
98 sclp_conbuf_callback(buffer, rc);
99 return;
100out_unlock:
101 spin_unlock_irqrestore(&sclp_con_lock, flags);
102}
103
104
105
106
107static void sclp_console_sync_queue(void)
108{
109 unsigned long flags;
110
111 spin_lock_irqsave(&sclp_con_lock, flags);
112 if (timer_pending(&sclp_con_timer))
113 del_timer(&sclp_con_timer);
114 while (sclp_con_queue_running) {
115 spin_unlock_irqrestore(&sclp_con_lock, flags);
116 sclp_sync_wait();
117 spin_lock_irqsave(&sclp_con_lock, flags);
118 }
119 spin_unlock_irqrestore(&sclp_con_lock, flags);
120}
121
122
123
124
125
126static void
127sclp_console_timeout(unsigned long data)
128{
129 sclp_conbuf_emit();
130}
131
132
133
134
135static int
136sclp_console_drop_buffer(void)
137{
138 struct list_head *list;
139 struct sclp_buffer *buffer;
140 void *page;
141
142 if (!sclp_console_drop)
143 return 0;
144 list = sclp_con_outqueue.next;
145 if (sclp_con_queue_running)
146
147 list = list->next;
148 if (list == &sclp_con_outqueue)
149 return 0;
150 list_del(list);
151 buffer = list_entry(list, struct sclp_buffer, list);
152 page = sclp_unmake_buffer(buffer);
153 list_add_tail((struct list_head *) page, &sclp_con_pages);
154 return 1;
155}
156
157
158
159
160static void
161sclp_console_write(struct console *console, const char *message,
162 unsigned int count)
163{
164 unsigned long flags;
165 void *page;
166 int written;
167
168 if (count == 0)
169 return;
170 spin_lock_irqsave(&sclp_con_lock, flags);
171
172
173
174
175 do {
176
177 if (sclp_conbuf == NULL) {
178 if (list_empty(&sclp_con_pages))
179 sclp_console_full++;
180 while (list_empty(&sclp_con_pages)) {
181 if (sclp_con_suspended)
182 goto out;
183 if (sclp_console_drop_buffer())
184 break;
185 spin_unlock_irqrestore(&sclp_con_lock, flags);
186 sclp_sync_wait();
187 spin_lock_irqsave(&sclp_con_lock, flags);
188 }
189 page = sclp_con_pages.next;
190 list_del((struct list_head *) page);
191 sclp_conbuf = sclp_make_buffer(page, sclp_con_columns,
192 sclp_con_width_htab);
193 }
194
195 written = sclp_write(sclp_conbuf, (const unsigned char *)
196 message, count);
197 if (written == count)
198 break;
199
200
201
202
203
204 spin_unlock_irqrestore(&sclp_con_lock, flags);
205 sclp_conbuf_emit();
206 spin_lock_irqsave(&sclp_con_lock, flags);
207 message += written;
208 count -= written;
209 } while (count > 0);
210
211 if (sclp_conbuf != NULL && sclp_chars_in_buffer(sclp_conbuf) != 0 &&
212 !timer_pending(&sclp_con_timer)) {
213 init_timer(&sclp_con_timer);
214 sclp_con_timer.function = sclp_console_timeout;
215 sclp_con_timer.data = 0UL;
216 sclp_con_timer.expires = jiffies + HZ/10;
217 add_timer(&sclp_con_timer);
218 }
219out:
220 spin_unlock_irqrestore(&sclp_con_lock, flags);
221}
222
223static struct tty_driver *
224sclp_console_device(struct console *c, int *index)
225{
226 *index = c->index;
227 return sclp_tty_driver;
228}
229
230
231
232
233static void
234sclp_console_flush(void)
235{
236 sclp_conbuf_emit();
237 sclp_console_sync_queue();
238}
239
240
241
242
243static void sclp_console_resume(void)
244{
245 unsigned long flags;
246
247 spin_lock_irqsave(&sclp_con_lock, flags);
248 sclp_con_suspended = 0;
249 spin_unlock_irqrestore(&sclp_con_lock, flags);
250 sclp_conbuf_emit();
251}
252
253
254
255
256static void sclp_console_suspend(void)
257{
258 unsigned long flags;
259
260 spin_lock_irqsave(&sclp_con_lock, flags);
261 sclp_con_suspended = 1;
262 spin_unlock_irqrestore(&sclp_con_lock, flags);
263 sclp_console_flush();
264}
265
266static int sclp_console_notify(struct notifier_block *self,
267 unsigned long event, void *data)
268{
269 sclp_console_flush();
270 return NOTIFY_OK;
271}
272
273static struct notifier_block on_panic_nb = {
274 .notifier_call = sclp_console_notify,
275 .priority = SCLP_PANIC_PRIO_CLIENT,
276};
277
278static struct notifier_block on_reboot_nb = {
279 .notifier_call = sclp_console_notify,
280 .priority = 1,
281};
282
283
284
285
286
287static struct console sclp_console =
288{
289 .name = sclp_console_name,
290 .write = sclp_console_write,
291 .device = sclp_console_device,
292 .flags = CON_PRINTBUFFER,
293 .index = 0
294};
295
296
297
298
299void sclp_console_pm_event(enum sclp_pm_event sclp_pm_event)
300{
301 switch (sclp_pm_event) {
302 case SCLP_PM_EVENT_FREEZE:
303 sclp_console_suspend();
304 break;
305 case SCLP_PM_EVENT_RESTORE:
306 case SCLP_PM_EVENT_THAW:
307 sclp_console_resume();
308 break;
309 }
310}
311
312
313
314
315static int __init
316sclp_console_init(void)
317{
318 void *page;
319 int i;
320 int rc;
321
322 if (!CONSOLE_IS_SCLP)
323 return 0;
324 rc = sclp_rw_init();
325 if (rc)
326 return rc;
327
328 INIT_LIST_HEAD(&sclp_con_pages);
329 for (i = 0; i < sclp_console_pages; i++) {
330 page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
331 list_add_tail(page, &sclp_con_pages);
332 }
333 INIT_LIST_HEAD(&sclp_con_outqueue);
334 spin_lock_init(&sclp_con_lock);
335 sclp_conbuf = NULL;
336 init_timer(&sclp_con_timer);
337
338
339 if (MACHINE_IS_VM)
340
341
342
343
344 sclp_con_columns = 76;
345 else
346 sclp_con_columns = 80;
347 sclp_con_width_htab = 8;
348
349
350 atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
351 register_reboot_notifier(&on_reboot_nb);
352 register_console(&sclp_console);
353 return 0;
354}
355
356console_initcall(sclp_console_init);
357