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Commit c0cefebc0b6ae1bc4c92672223a54e1ee96ea7f0

Authored by Amit Shah
Committed by Benjamin Herrenschmidt
1 parent 529586dc39
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

hvc_console: Export (GPL'ed) hvc_remove 

The virtio console, which uses hvc, will get the ability to hot-unplug
ports. Export hvc_remove so that virtio_console can disassociate with
hvc.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Cc: linuxppc-dev@ozlabs.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Showing 1 changed file with 1 additions and 0 deletions Inline Diff

drivers/char/hvc_console.c
Diff comments   View file @ c0cefeb
1 /* 1 /*
2 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM 2 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
3 * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM 3 * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
4 * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp. 4 * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
5 * Copyright (C) 2004 IBM Corporation 5 * Copyright (C) 2004 IBM Corporation
6 * 6 *
7 * Additional Author(s): 7 * Additional Author(s):
8 * Ryan S. Arnold <rsa@us.ibm.com> 8 * Ryan S. Arnold <rsa@us.ibm.com>
9 * 9 *
10 * This program is free software; you can redistribute it and/or modify 10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by 11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or 12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version. 13 * (at your option) any later version.
14 * 14 *
15 * This program is distributed in the hope that it will be useful, 15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details. 18 * GNU General Public License for more details.
19 * 19 *
20 * You should have received a copy of the GNU General Public License 20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software 21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */ 23 */
24 24
25 #include <linux/console.h> 25 #include <linux/console.h>
26 #include <linux/cpumask.h> 26 #include <linux/cpumask.h>
27 #include <linux/init.h> 27 #include <linux/init.h>
28 #include <linux/kbd_kern.h> 28 #include <linux/kbd_kern.h>
29 #include <linux/kernel.h> 29 #include <linux/kernel.h>
30 #include <linux/kthread.h> 30 #include <linux/kthread.h>
31 #include <linux/list.h> 31 #include <linux/list.h>
32 #include <linux/module.h> 32 #include <linux/module.h>
33 #include <linux/major.h> 33 #include <linux/major.h>
34 #include <linux/sysrq.h> 34 #include <linux/sysrq.h>
35 #include <linux/tty.h> 35 #include <linux/tty.h>
36 #include <linux/tty_flip.h> 36 #include <linux/tty_flip.h>
37 #include <linux/sched.h> 37 #include <linux/sched.h>
38 #include <linux/spinlock.h> 38 #include <linux/spinlock.h>
39 #include <linux/delay.h> 39 #include <linux/delay.h>
40 #include <linux/freezer.h> 40 #include <linux/freezer.h>
41 41
42 #include <asm/uaccess.h> 42 #include <asm/uaccess.h>
43 43
44 #include "hvc_console.h" 44 #include "hvc_console.h"
45 45
46 #define HVC_MAJOR 229 46 #define HVC_MAJOR 229
47 #define HVC_MINOR 0 47 #define HVC_MINOR 0
48 48
49 /* 49 /*
50 * Wait this long per iteration while trying to push buffered data to the 50 * Wait this long per iteration while trying to push buffered data to the
51 * hypervisor before allowing the tty to complete a close operation. 51 * hypervisor before allowing the tty to complete a close operation.
52 */ 52 */
53 #define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */ 53 #define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */
54 54
55 /* 55 /*
56 * These sizes are most efficient for vio, because they are the 56 * These sizes are most efficient for vio, because they are the
57 * native transfer size. We could make them selectable in the 57 * native transfer size. We could make them selectable in the
58 * future to better deal with backends that want other buffer sizes. 58 * future to better deal with backends that want other buffer sizes.
59 */ 59 */
60 #define N_OUTBUF 16 60 #define N_OUTBUF 16
61 #define N_INBUF 16 61 #define N_INBUF 16
62 62
63 #define __ALIGNED__ __attribute__((__aligned__(sizeof(long)))) 63 #define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
64 64
65 static struct tty_driver *hvc_driver; 65 static struct tty_driver *hvc_driver;
66 static struct task_struct *hvc_task; 66 static struct task_struct *hvc_task;
67 67
68 /* Picks up late kicks after list walk but before schedule() */ 68 /* Picks up late kicks after list walk but before schedule() */
69 static int hvc_kicked; 69 static int hvc_kicked;
70 70
71 static int hvc_init(void); 71 static int hvc_init(void);
72 72
73 #ifdef CONFIG_MAGIC_SYSRQ 73 #ifdef CONFIG_MAGIC_SYSRQ
74 static int sysrq_pressed; 74 static int sysrq_pressed;
75 #endif 75 #endif
76 76
77 /* dynamic list of hvc_struct instances */ 77 /* dynamic list of hvc_struct instances */
78 static LIST_HEAD(hvc_structs); 78 static LIST_HEAD(hvc_structs);
79 79
80 /* 80 /*
81 * Protect the list of hvc_struct instances from inserts and removals during 81 * Protect the list of hvc_struct instances from inserts and removals during
82 * list traversal. 82 * list traversal.
83 */ 83 */
84 static DEFINE_SPINLOCK(hvc_structs_lock); 84 static DEFINE_SPINLOCK(hvc_structs_lock);
85 85
86 /* 86 /*
87 * This value is used to assign a tty->index value to a hvc_struct based 87 * This value is used to assign a tty->index value to a hvc_struct based
88 * upon order of exposure via hvc_probe(), when we can not match it to 88 * upon order of exposure via hvc_probe(), when we can not match it to
89 * a console candidate registered with hvc_instantiate(). 89 * a console candidate registered with hvc_instantiate().
90 */ 90 */
91 static int last_hvc = -1; 91 static int last_hvc = -1;
92 92
93 /* 93 /*
94 * Do not call this function with either the hvc_structs_lock or the hvc_struct 94 * Do not call this function with either the hvc_structs_lock or the hvc_struct
95 * lock held. If successful, this function increments the kref reference 95 * lock held. If successful, this function increments the kref reference
96 * count against the target hvc_struct so it should be released when finished. 96 * count against the target hvc_struct so it should be released when finished.
97 */ 97 */
98 static struct hvc_struct *hvc_get_by_index(int index) 98 static struct hvc_struct *hvc_get_by_index(int index)
99 { 99 {
100 struct hvc_struct *hp; 100 struct hvc_struct *hp;
101 unsigned long flags; 101 unsigned long flags;
102 102
103 spin_lock(&hvc_structs_lock); 103 spin_lock(&hvc_structs_lock);
104 104
105 list_for_each_entry(hp, &hvc_structs, next) { 105 list_for_each_entry(hp, &hvc_structs, next) {
106 spin_lock_irqsave(&hp->lock, flags); 106 spin_lock_irqsave(&hp->lock, flags);
107 if (hp->index == index) { 107 if (hp->index == index) {
108 kref_get(&hp->kref); 108 kref_get(&hp->kref);
109 spin_unlock_irqrestore(&hp->lock, flags); 109 spin_unlock_irqrestore(&hp->lock, flags);
110 spin_unlock(&hvc_structs_lock); 110 spin_unlock(&hvc_structs_lock);
111 return hp; 111 return hp;
112 } 112 }
113 spin_unlock_irqrestore(&hp->lock, flags); 113 spin_unlock_irqrestore(&hp->lock, flags);
114 } 114 }
115 hp = NULL; 115 hp = NULL;
116 116
117 spin_unlock(&hvc_structs_lock); 117 spin_unlock(&hvc_structs_lock);
118 return hp; 118 return hp;
119 } 119 }
120 120
121 121
122 /* 122 /*
123 * Initial console vtermnos for console API usage prior to full console 123 * Initial console vtermnos for console API usage prior to full console
124 * initialization. Any vty adapter outside this range will not have usable 124 * initialization. Any vty adapter outside this range will not have usable
125 * console interfaces but can still be used as a tty device. This has to be 125 * console interfaces but can still be used as a tty device. This has to be
126 * static because kmalloc will not work during early console init. 126 * static because kmalloc will not work during early console init.
127 */ 127 */
128 static struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES]; 128 static struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES];
129 static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] = 129 static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] =
130 {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1}; 130 {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1};
131 131
132 /* 132 /*
133 * Console APIs, NOT TTY. These APIs are available immediately when 133 * Console APIs, NOT TTY. These APIs are available immediately when
134 * hvc_console_setup() finds adapters. 134 * hvc_console_setup() finds adapters.
135 */ 135 */
136 136
137 static void hvc_console_print(struct console *co, const char *b, 137 static void hvc_console_print(struct console *co, const char *b,
138 unsigned count) 138 unsigned count)
139 { 139 {
140 char c[N_OUTBUF] __ALIGNED__; 140 char c[N_OUTBUF] __ALIGNED__;
141 unsigned i = 0, n = 0; 141 unsigned i = 0, n = 0;
142 int r, donecr = 0, index = co->index; 142 int r, donecr = 0, index = co->index;
143 143
144 /* Console access attempt outside of acceptable console range. */ 144 /* Console access attempt outside of acceptable console range. */
145 if (index >= MAX_NR_HVC_CONSOLES) 145 if (index >= MAX_NR_HVC_CONSOLES)
146 return; 146 return;
147 147
148 /* This console adapter was removed so it is not usable. */ 148 /* This console adapter was removed so it is not usable. */
149 if (vtermnos[index] < 0) 149 if (vtermnos[index] < 0)
150 return; 150 return;
151 151
152 while (count > 0 || i > 0) { 152 while (count > 0 || i > 0) {
153 if (count > 0 && i < sizeof(c)) { 153 if (count > 0 && i < sizeof(c)) {
154 if (b[n] == '\n' && !donecr) { 154 if (b[n] == '\n' && !donecr) {
155 c[i++] = '\r'; 155 c[i++] = '\r';
156 donecr = 1; 156 donecr = 1;
157 } else { 157 } else {
158 c[i++] = b[n++]; 158 c[i++] = b[n++];
159 donecr = 0; 159 donecr = 0;
160 --count; 160 --count;
161 } 161 }
162 } else { 162 } else {
163 r = cons_ops[index]->put_chars(vtermnos[index], c, i); 163 r = cons_ops[index]->put_chars(vtermnos[index], c, i);
164 if (r <= 0) { 164 if (r <= 0) {
165 /* throw away chars on error */ 165 /* throw away chars on error */
166 i = 0; 166 i = 0;
167 } else if (r > 0) { 167 } else if (r > 0) {
168 i -= r; 168 i -= r;
169 if (i > 0) 169 if (i > 0)
170 memmove(c, c+r, i); 170 memmove(c, c+r, i);
171 } 171 }
172 } 172 }
173 } 173 }
174 } 174 }
175 175
176 static struct tty_driver *hvc_console_device(struct console *c, int *index) 176 static struct tty_driver *hvc_console_device(struct console *c, int *index)
177 { 177 {
178 if (vtermnos[c->index] == -1) 178 if (vtermnos[c->index] == -1)
179 return NULL; 179 return NULL;
180 180
181 *index = c->index; 181 *index = c->index;
182 return hvc_driver; 182 return hvc_driver;
183 } 183 }
184 184
185 static int __init hvc_console_setup(struct console *co, char *options) 185 static int __init hvc_console_setup(struct console *co, char *options)
186 { 186 {
187 if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES) 187 if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES)
188 return -ENODEV; 188 return -ENODEV;
189 189
190 if (vtermnos[co->index] == -1) 190 if (vtermnos[co->index] == -1)
191 return -ENODEV; 191 return -ENODEV;
192 192
193 return 0; 193 return 0;
194 } 194 }
195 195
196 static struct console hvc_con_driver = { 196 static struct console hvc_con_driver = {
197 .name = "hvc", 197 .name = "hvc",
198 .write = hvc_console_print, 198 .write = hvc_console_print,
199 .device = hvc_console_device, 199 .device = hvc_console_device,
200 .setup = hvc_console_setup, 200 .setup = hvc_console_setup,
201 .flags = CON_PRINTBUFFER, 201 .flags = CON_PRINTBUFFER,
202 .index = -1, 202 .index = -1,
203 }; 203 };
204 204
205 /* 205 /*
206 * Early console initialization. Precedes driver initialization. 206 * Early console initialization. Precedes driver initialization.
207 * 207 *
208 * (1) we are first, and the user specified another driver 208 * (1) we are first, and the user specified another driver
209 * -- index will remain -1 209 * -- index will remain -1
210 * (2) we are first and the user specified no driver 210 * (2) we are first and the user specified no driver
211 * -- index will be set to 0, then we will fail setup. 211 * -- index will be set to 0, then we will fail setup.
212 * (3) we are first and the user specified our driver 212 * (3) we are first and the user specified our driver
213 * -- index will be set to user specified driver, and we will fail 213 * -- index will be set to user specified driver, and we will fail
214 * (4) we are after driver, and this initcall will register us 214 * (4) we are after driver, and this initcall will register us
215 * -- if the user didn't specify a driver then the console will match 215 * -- if the user didn't specify a driver then the console will match
216 * 216 *
217 * Note that for cases 2 and 3, we will match later when the io driver 217 * Note that for cases 2 and 3, we will match later when the io driver
218 * calls hvc_instantiate() and call register again. 218 * calls hvc_instantiate() and call register again.
219 */ 219 */
220 static int __init hvc_console_init(void) 220 static int __init hvc_console_init(void)
221 { 221 {
222 register_console(&hvc_con_driver); 222 register_console(&hvc_con_driver);
223 return 0; 223 return 0;
224 } 224 }
225 console_initcall(hvc_console_init); 225 console_initcall(hvc_console_init);
226 226
227 /* callback when the kboject ref count reaches zero. */ 227 /* callback when the kboject ref count reaches zero. */
228 static void destroy_hvc_struct(struct kref *kref) 228 static void destroy_hvc_struct(struct kref *kref)
229 { 229 {
230 struct hvc_struct *hp = container_of(kref, struct hvc_struct, kref); 230 struct hvc_struct *hp = container_of(kref, struct hvc_struct, kref);
231 unsigned long flags; 231 unsigned long flags;
232 232
233 spin_lock(&hvc_structs_lock); 233 spin_lock(&hvc_structs_lock);
234 234
235 spin_lock_irqsave(&hp->lock, flags); 235 spin_lock_irqsave(&hp->lock, flags);
236 list_del(&(hp->next)); 236 list_del(&(hp->next));
237 spin_unlock_irqrestore(&hp->lock, flags); 237 spin_unlock_irqrestore(&hp->lock, flags);
238 238
239 spin_unlock(&hvc_structs_lock); 239 spin_unlock(&hvc_structs_lock);
240 240
241 kfree(hp); 241 kfree(hp);
242 } 242 }
243 243
244 /* 244 /*
245 * hvc_instantiate() is an early console discovery method which locates 245 * hvc_instantiate() is an early console discovery method which locates
246 * consoles * prior to the vio subsystem discovering them. Hotplugged 246 * consoles * prior to the vio subsystem discovering them. Hotplugged
247 * vty adapters do NOT get an hvc_instantiate() callback since they 247 * vty adapters do NOT get an hvc_instantiate() callback since they
248 * appear after early console init. 248 * appear after early console init.
249 */ 249 */
250 int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops) 250 int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops)
251 { 251 {
252 struct hvc_struct *hp; 252 struct hvc_struct *hp;
253 253
254 if (index < 0 || index >= MAX_NR_HVC_CONSOLES) 254 if (index < 0 || index >= MAX_NR_HVC_CONSOLES)
255 return -1; 255 return -1;
256 256
257 if (vtermnos[index] != -1) 257 if (vtermnos[index] != -1)
258 return -1; 258 return -1;
259 259
260 /* make sure no no tty has been registered in this index */ 260 /* make sure no no tty has been registered in this index */
261 hp = hvc_get_by_index(index); 261 hp = hvc_get_by_index(index);
262 if (hp) { 262 if (hp) {
263 kref_put(&hp->kref, destroy_hvc_struct); 263 kref_put(&hp->kref, destroy_hvc_struct);
264 return -1; 264 return -1;
265 } 265 }
266 266
267 vtermnos[index] = vtermno; 267 vtermnos[index] = vtermno;
268 cons_ops[index] = ops; 268 cons_ops[index] = ops;
269 269
270 /* reserve all indices up to and including this index */ 270 /* reserve all indices up to and including this index */
271 if (last_hvc < index) 271 if (last_hvc < index)
272 last_hvc = index; 272 last_hvc = index;
273 273
274 /* if this index is what the user requested, then register 274 /* if this index is what the user requested, then register
275 * now (setup won't fail at this point). It's ok to just 275 * now (setup won't fail at this point). It's ok to just
276 * call register again if previously .setup failed. 276 * call register again if previously .setup failed.
277 */ 277 */
278 if (index == hvc_con_driver.index) 278 if (index == hvc_con_driver.index)
279 register_console(&hvc_con_driver); 279 register_console(&hvc_con_driver);
280 280
281 return 0; 281 return 0;
282 } 282 }
283 EXPORT_SYMBOL_GPL(hvc_instantiate); 283 EXPORT_SYMBOL_GPL(hvc_instantiate);
284 284
285 /* Wake the sleeping khvcd */ 285 /* Wake the sleeping khvcd */
286 void hvc_kick(void) 286 void hvc_kick(void)
287 { 287 {
288 hvc_kicked = 1; 288 hvc_kicked = 1;
289 wake_up_process(hvc_task); 289 wake_up_process(hvc_task);
290 } 290 }
291 EXPORT_SYMBOL_GPL(hvc_kick); 291 EXPORT_SYMBOL_GPL(hvc_kick);
292 292
293 static void hvc_unthrottle(struct tty_struct *tty) 293 static void hvc_unthrottle(struct tty_struct *tty)
294 { 294 {
295 hvc_kick(); 295 hvc_kick();
296 } 296 }
297 297
298 /* 298 /*
299 * The TTY interface won't be used until after the vio layer has exposed the vty 299 * The TTY interface won't be used until after the vio layer has exposed the vty
300 * adapter to the kernel. 300 * adapter to the kernel.
301 */ 301 */
302 static int hvc_open(struct tty_struct *tty, struct file * filp) 302 static int hvc_open(struct tty_struct *tty, struct file * filp)
303 { 303 {
304 struct hvc_struct *hp; 304 struct hvc_struct *hp;
305 unsigned long flags; 305 unsigned long flags;
306 int rc = 0; 306 int rc = 0;
307 307
308 /* Auto increments kref reference if found. */ 308 /* Auto increments kref reference if found. */
309 if (!(hp = hvc_get_by_index(tty->index))) 309 if (!(hp = hvc_get_by_index(tty->index)))
310 return -ENODEV; 310 return -ENODEV;
311 311
312 spin_lock_irqsave(&hp->lock, flags); 312 spin_lock_irqsave(&hp->lock, flags);
313 /* Check and then increment for fast path open. */ 313 /* Check and then increment for fast path open. */
314 if (hp->count++ > 0) { 314 if (hp->count++ > 0) {
315 spin_unlock_irqrestore(&hp->lock, flags); 315 spin_unlock_irqrestore(&hp->lock, flags);
316 hvc_kick(); 316 hvc_kick();
317 return 0; 317 return 0;
318 } /* else count == 0 */ 318 } /* else count == 0 */
319 319
320 tty->driver_data = hp; 320 tty->driver_data = hp;
321 321
322 hp->tty = tty; 322 hp->tty = tty;
323 323
324 spin_unlock_irqrestore(&hp->lock, flags); 324 spin_unlock_irqrestore(&hp->lock, flags);
325 325
326 if (hp->ops->notifier_add) 326 if (hp->ops->notifier_add)
327 rc = hp->ops->notifier_add(hp, hp->data); 327 rc = hp->ops->notifier_add(hp, hp->data);
328 328
329 /* 329 /*
330 * If the notifier fails we return an error. The tty layer 330 * If the notifier fails we return an error. The tty layer
331 * will call hvc_close() after a failed open but we don't want to clean 331 * will call hvc_close() after a failed open but we don't want to clean
332 * up there so we'll clean up here and clear out the previously set 332 * up there so we'll clean up here and clear out the previously set
333 * tty fields and return the kref reference. 333 * tty fields and return the kref reference.
334 */ 334 */
335 if (rc) { 335 if (rc) {
336 spin_lock_irqsave(&hp->lock, flags); 336 spin_lock_irqsave(&hp->lock, flags);
337 hp->tty = NULL; 337 hp->tty = NULL;
338 spin_unlock_irqrestore(&hp->lock, flags); 338 spin_unlock_irqrestore(&hp->lock, flags);
339 tty->driver_data = NULL; 339 tty->driver_data = NULL;
340 kref_put(&hp->kref, destroy_hvc_struct); 340 kref_put(&hp->kref, destroy_hvc_struct);
341 printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc); 341 printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc);
342 } 342 }
343 /* Force wakeup of the polling thread */ 343 /* Force wakeup of the polling thread */
344 hvc_kick(); 344 hvc_kick();
345 345
346 return rc; 346 return rc;
347 } 347 }
348 348
349 static void hvc_close(struct tty_struct *tty, struct file * filp) 349 static void hvc_close(struct tty_struct *tty, struct file * filp)
350 { 350 {
351 struct hvc_struct *hp; 351 struct hvc_struct *hp;
352 unsigned long flags; 352 unsigned long flags;
353 353
354 if (tty_hung_up_p(filp)) 354 if (tty_hung_up_p(filp))
355 return; 355 return;
356 356
357 /* 357 /*
358 * No driver_data means that this close was issued after a failed 358 * No driver_data means that this close was issued after a failed
359 * hvc_open by the tty layer's release_dev() function and we can just 359 * hvc_open by the tty layer's release_dev() function and we can just
360 * exit cleanly because the kref reference wasn't made. 360 * exit cleanly because the kref reference wasn't made.
361 */ 361 */
362 if (!tty->driver_data) 362 if (!tty->driver_data)
363 return; 363 return;
364 364
365 hp = tty->driver_data; 365 hp = tty->driver_data;
366 spin_lock_irqsave(&hp->lock, flags); 366 spin_lock_irqsave(&hp->lock, flags);
367 367
368 if (--hp->count == 0) { 368 if (--hp->count == 0) {
369 /* We are done with the tty pointer now. */ 369 /* We are done with the tty pointer now. */
370 hp->tty = NULL; 370 hp->tty = NULL;
371 spin_unlock_irqrestore(&hp->lock, flags); 371 spin_unlock_irqrestore(&hp->lock, flags);
372 372
373 if (hp->ops->notifier_del) 373 if (hp->ops->notifier_del)
374 hp->ops->notifier_del(hp, hp->data); 374 hp->ops->notifier_del(hp, hp->data);
375 375
376 /* cancel pending tty resize work */ 376 /* cancel pending tty resize work */
377 cancel_work_sync(&hp->tty_resize); 377 cancel_work_sync(&hp->tty_resize);
378 378
379 /* 379 /*
380 * Chain calls chars_in_buffer() and returns immediately if 380 * Chain calls chars_in_buffer() and returns immediately if
381 * there is no buffered data otherwise sleeps on a wait queue 381 * there is no buffered data otherwise sleeps on a wait queue
382 * waking periodically to check chars_in_buffer(). 382 * waking periodically to check chars_in_buffer().
383 */ 383 */
384 tty_wait_until_sent(tty, HVC_CLOSE_WAIT); 384 tty_wait_until_sent(tty, HVC_CLOSE_WAIT);
385 } else { 385 } else {
386 if (hp->count < 0) 386 if (hp->count < 0)
387 printk(KERN_ERR "hvc_close %X: oops, count is %d\n", 387 printk(KERN_ERR "hvc_close %X: oops, count is %d\n",
388 hp->vtermno, hp->count); 388 hp->vtermno, hp->count);
389 spin_unlock_irqrestore(&hp->lock, flags); 389 spin_unlock_irqrestore(&hp->lock, flags);
390 } 390 }
391 391
392 kref_put(&hp->kref, destroy_hvc_struct); 392 kref_put(&hp->kref, destroy_hvc_struct);
393 } 393 }
394 394
395 static void hvc_hangup(struct tty_struct *tty) 395 static void hvc_hangup(struct tty_struct *tty)
396 { 396 {
397 struct hvc_struct *hp = tty->driver_data; 397 struct hvc_struct *hp = tty->driver_data;
398 unsigned long flags; 398 unsigned long flags;
399 int temp_open_count; 399 int temp_open_count;
400 400
401 if (!hp) 401 if (!hp)
402 return; 402 return;
403 403
404 /* cancel pending tty resize work */ 404 /* cancel pending tty resize work */
405 cancel_work_sync(&hp->tty_resize); 405 cancel_work_sync(&hp->tty_resize);
406 406
407 spin_lock_irqsave(&hp->lock, flags); 407 spin_lock_irqsave(&hp->lock, flags);
408 408
409 /* 409 /*
410 * The N_TTY line discipline has problems such that in a close vs 410 * The N_TTY line discipline has problems such that in a close vs
411 * open->hangup case this can be called after the final close so prevent 411 * open->hangup case this can be called after the final close so prevent
412 * that from happening for now. 412 * that from happening for now.
413 */ 413 */
414 if (hp->count <= 0) { 414 if (hp->count <= 0) {
415 spin_unlock_irqrestore(&hp->lock, flags); 415 spin_unlock_irqrestore(&hp->lock, flags);
416 return; 416 return;
417 } 417 }
418 418
419 temp_open_count = hp->count; 419 temp_open_count = hp->count;
420 hp->count = 0; 420 hp->count = 0;
421 hp->n_outbuf = 0; 421 hp->n_outbuf = 0;
422 hp->tty = NULL; 422 hp->tty = NULL;
423 423
424 spin_unlock_irqrestore(&hp->lock, flags); 424 spin_unlock_irqrestore(&hp->lock, flags);
425 425
426 if (hp->ops->notifier_hangup) 426 if (hp->ops->notifier_hangup)
427 hp->ops->notifier_hangup(hp, hp->data); 427 hp->ops->notifier_hangup(hp, hp->data);
428 428
429 while(temp_open_count) { 429 while(temp_open_count) {
430 --temp_open_count; 430 --temp_open_count;
431 kref_put(&hp->kref, destroy_hvc_struct); 431 kref_put(&hp->kref, destroy_hvc_struct);
432 } 432 }
433 } 433 }
434 434
435 /* 435 /*
436 * Push buffered characters whether they were just recently buffered or waiting 436 * Push buffered characters whether they were just recently buffered or waiting
437 * on a blocked hypervisor. Call this function with hp->lock held. 437 * on a blocked hypervisor. Call this function with hp->lock held.
438 */ 438 */
439 static int hvc_push(struct hvc_struct *hp) 439 static int hvc_push(struct hvc_struct *hp)
440 { 440 {
441 int n; 441 int n;
442 442
443 n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf); 443 n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf);
444 if (n <= 0) { 444 if (n <= 0) {
445 if (n == 0) { 445 if (n == 0) {
446 hp->do_wakeup = 1; 446 hp->do_wakeup = 1;
447 return 0; 447 return 0;
448 } 448 }
449 /* throw away output on error; this happens when 449 /* throw away output on error; this happens when
450 there is no session connected to the vterm. */ 450 there is no session connected to the vterm. */
451 hp->n_outbuf = 0; 451 hp->n_outbuf = 0;
452 } else 452 } else
453 hp->n_outbuf -= n; 453 hp->n_outbuf -= n;
454 if (hp->n_outbuf > 0) 454 if (hp->n_outbuf > 0)
455 memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf); 455 memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf);
456 else 456 else
457 hp->do_wakeup = 1; 457 hp->do_wakeup = 1;
458 458
459 return n; 459 return n;
460 } 460 }
461 461
462 static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count) 462 static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count)
463 { 463 {
464 struct hvc_struct *hp = tty->driver_data; 464 struct hvc_struct *hp = tty->driver_data;
465 unsigned long flags; 465 unsigned long flags;
466 int rsize, written = 0; 466 int rsize, written = 0;
467 467
468 /* This write was probably executed during a tty close. */ 468 /* This write was probably executed during a tty close. */
469 if (!hp) 469 if (!hp)
470 return -EPIPE; 470 return -EPIPE;
471 471
472 if (hp->count <= 0) 472 if (hp->count <= 0)
473 return -EIO; 473 return -EIO;
474 474
475 spin_lock_irqsave(&hp->lock, flags); 475 spin_lock_irqsave(&hp->lock, flags);
476 476
477 /* Push pending writes */ 477 /* Push pending writes */
478 if (hp->n_outbuf > 0) 478 if (hp->n_outbuf > 0)
479 hvc_push(hp); 479 hvc_push(hp);
480 480
481 while (count > 0 && (rsize = hp->outbuf_size - hp->n_outbuf) > 0) { 481 while (count > 0 && (rsize = hp->outbuf_size - hp->n_outbuf) > 0) {
482 if (rsize > count) 482 if (rsize > count)
483 rsize = count; 483 rsize = count;
484 memcpy(hp->outbuf + hp->n_outbuf, buf, rsize); 484 memcpy(hp->outbuf + hp->n_outbuf, buf, rsize);
485 count -= rsize; 485 count -= rsize;
486 buf += rsize; 486 buf += rsize;
487 hp->n_outbuf += rsize; 487 hp->n_outbuf += rsize;
488 written += rsize; 488 written += rsize;
489 hvc_push(hp); 489 hvc_push(hp);
490 } 490 }
491 spin_unlock_irqrestore(&hp->lock, flags); 491 spin_unlock_irqrestore(&hp->lock, flags);
492 492
493 /* 493 /*
494 * Racy, but harmless, kick thread if there is still pending data. 494 * Racy, but harmless, kick thread if there is still pending data.
495 */ 495 */
496 if (hp->n_outbuf) 496 if (hp->n_outbuf)
497 hvc_kick(); 497 hvc_kick();
498 498
499 return written; 499 return written;
500 } 500 }
501 501
502 /** 502 /**
503 * hvc_set_winsz() - Resize the hvc tty terminal window. 503 * hvc_set_winsz() - Resize the hvc tty terminal window.
504 * @work: work structure. 504 * @work: work structure.
505 * 505 *
506 * The routine shall not be called within an atomic context because it 506 * The routine shall not be called within an atomic context because it
507 * might sleep. 507 * might sleep.
508 * 508 *
509 * Locking: hp->lock 509 * Locking: hp->lock
510 */ 510 */
511 static void hvc_set_winsz(struct work_struct *work) 511 static void hvc_set_winsz(struct work_struct *work)
512 { 512 {
513 struct hvc_struct *hp; 513 struct hvc_struct *hp;
514 unsigned long hvc_flags; 514 unsigned long hvc_flags;
515 struct tty_struct *tty; 515 struct tty_struct *tty;
516 struct winsize ws; 516 struct winsize ws;
517 517
518 hp = container_of(work, struct hvc_struct, tty_resize); 518 hp = container_of(work, struct hvc_struct, tty_resize);
519 519
520 spin_lock_irqsave(&hp->lock, hvc_flags); 520 spin_lock_irqsave(&hp->lock, hvc_flags);
521 if (!hp->tty) { 521 if (!hp->tty) {
522 spin_unlock_irqrestore(&hp->lock, hvc_flags); 522 spin_unlock_irqrestore(&hp->lock, hvc_flags);
523 return; 523 return;
524 } 524 }
525 ws = hp->ws; 525 ws = hp->ws;
526 tty = tty_kref_get(hp->tty); 526 tty = tty_kref_get(hp->tty);
527 spin_unlock_irqrestore(&hp->lock, hvc_flags); 527 spin_unlock_irqrestore(&hp->lock, hvc_flags);
528 528
529 tty_do_resize(tty, &ws); 529 tty_do_resize(tty, &ws);
530 tty_kref_put(tty); 530 tty_kref_put(tty);
531 } 531 }
532 532
533 /* 533 /*
534 * This is actually a contract between the driver and the tty layer outlining 534 * This is actually a contract between the driver and the tty layer outlining
535 * how much write room the driver can guarantee will be sent OR BUFFERED. This 535 * how much write room the driver can guarantee will be sent OR BUFFERED. This
536 * driver MUST honor the return value. 536 * driver MUST honor the return value.
537 */ 537 */
538 static int hvc_write_room(struct tty_struct *tty) 538 static int hvc_write_room(struct tty_struct *tty)
539 { 539 {
540 struct hvc_struct *hp = tty->driver_data; 540 struct hvc_struct *hp = tty->driver_data;
541 541
542 if (!hp) 542 if (!hp)
543 return -1; 543 return -1;
544 544
545 return hp->outbuf_size - hp->n_outbuf; 545 return hp->outbuf_size - hp->n_outbuf;
546 } 546 }
547 547
548 static int hvc_chars_in_buffer(struct tty_struct *tty) 548 static int hvc_chars_in_buffer(struct tty_struct *tty)
549 { 549 {
550 struct hvc_struct *hp = tty->driver_data; 550 struct hvc_struct *hp = tty->driver_data;
551 551
552 if (!hp) 552 if (!hp)
553 return 0; 553 return 0;
554 return hp->n_outbuf; 554 return hp->n_outbuf;
555 } 555 }
556 556
557 /* 557 /*
558 * timeout will vary between the MIN and MAX values defined here. By default 558 * timeout will vary between the MIN and MAX values defined here. By default
559 * and during console activity we will use a default MIN_TIMEOUT of 10. When 559 * and during console activity we will use a default MIN_TIMEOUT of 10. When
560 * the console is idle, we increase the timeout value on each pass through 560 * the console is idle, we increase the timeout value on each pass through
561 * msleep until we reach the max. This may be noticeable as a brief (average 561 * msleep until we reach the max. This may be noticeable as a brief (average
562 * one second) delay on the console before the console responds to input when 562 * one second) delay on the console before the console responds to input when
563 * there has been no input for some time. 563 * there has been no input for some time.
564 */ 564 */
565 #define MIN_TIMEOUT (10) 565 #define MIN_TIMEOUT (10)
566 #define MAX_TIMEOUT (2000) 566 #define MAX_TIMEOUT (2000)
567 static u32 timeout = MIN_TIMEOUT; 567 static u32 timeout = MIN_TIMEOUT;
568 568
569 #define HVC_POLL_READ 0x00000001 569 #define HVC_POLL_READ 0x00000001
570 #define HVC_POLL_WRITE 0x00000002 570 #define HVC_POLL_WRITE 0x00000002
571 571
572 int hvc_poll(struct hvc_struct *hp) 572 int hvc_poll(struct hvc_struct *hp)
573 { 573 {
574 struct tty_struct *tty; 574 struct tty_struct *tty;
575 int i, n, poll_mask = 0; 575 int i, n, poll_mask = 0;
576 char buf[N_INBUF] __ALIGNED__; 576 char buf[N_INBUF] __ALIGNED__;
577 unsigned long flags; 577 unsigned long flags;
578 int read_total = 0; 578 int read_total = 0;
579 int written_total = 0; 579 int written_total = 0;
580 580
581 spin_lock_irqsave(&hp->lock, flags); 581 spin_lock_irqsave(&hp->lock, flags);
582 582
583 /* Push pending writes */ 583 /* Push pending writes */
584 if (hp->n_outbuf > 0) 584 if (hp->n_outbuf > 0)
585 written_total = hvc_push(hp); 585 written_total = hvc_push(hp);
586 586
587 /* Reschedule us if still some write pending */ 587 /* Reschedule us if still some write pending */
588 if (hp->n_outbuf > 0) { 588 if (hp->n_outbuf > 0) {
589 poll_mask |= HVC_POLL_WRITE; 589 poll_mask |= HVC_POLL_WRITE;
590 /* If hvc_push() was not able to write, sleep a few msecs */ 590 /* If hvc_push() was not able to write, sleep a few msecs */
591 timeout = (written_total) ? 0 : MIN_TIMEOUT; 591 timeout = (written_total) ? 0 : MIN_TIMEOUT;
592 } 592 }
593 593
594 /* No tty attached, just skip */ 594 /* No tty attached, just skip */
595 tty = hp->tty; 595 tty = hp->tty;
596 if (tty == NULL) 596 if (tty == NULL)
597 goto bail; 597 goto bail;
598 598
599 /* Now check if we can get data (are we throttled ?) */ 599 /* Now check if we can get data (are we throttled ?) */
600 if (test_bit(TTY_THROTTLED, &tty->flags)) 600 if (test_bit(TTY_THROTTLED, &tty->flags))
601 goto throttled; 601 goto throttled;
602 602
603 /* If we aren't notifier driven and aren't throttled, we always 603 /* If we aren't notifier driven and aren't throttled, we always
604 * request a reschedule 604 * request a reschedule
605 */ 605 */
606 if (!hp->irq_requested) 606 if (!hp->irq_requested)
607 poll_mask |= HVC_POLL_READ; 607 poll_mask |= HVC_POLL_READ;
608 608
609 /* Read data if any */ 609 /* Read data if any */
610 for (;;) { 610 for (;;) {
611 int count = tty_buffer_request_room(tty, N_INBUF); 611 int count = tty_buffer_request_room(tty, N_INBUF);
612 612
613 /* If flip is full, just reschedule a later read */ 613 /* If flip is full, just reschedule a later read */
614 if (count == 0) { 614 if (count == 0) {
615 poll_mask |= HVC_POLL_READ; 615 poll_mask |= HVC_POLL_READ;
616 break; 616 break;
617 } 617 }
618 618
619 n = hp->ops->get_chars(hp->vtermno, buf, count); 619 n = hp->ops->get_chars(hp->vtermno, buf, count);
620 if (n <= 0) { 620 if (n <= 0) {
621 /* Hangup the tty when disconnected from host */ 621 /* Hangup the tty when disconnected from host */
622 if (n == -EPIPE) { 622 if (n == -EPIPE) {
623 spin_unlock_irqrestore(&hp->lock, flags); 623 spin_unlock_irqrestore(&hp->lock, flags);
624 tty_hangup(tty); 624 tty_hangup(tty);
625 spin_lock_irqsave(&hp->lock, flags); 625 spin_lock_irqsave(&hp->lock, flags);
626 } else if ( n == -EAGAIN ) { 626 } else if ( n == -EAGAIN ) {
627 /* 627 /*
628 * Some back-ends can only ensure a certain min 628 * Some back-ends can only ensure a certain min
629 * num of bytes read, which may be > 'count'. 629 * num of bytes read, which may be > 'count'.
630 * Let the tty clear the flip buff to make room. 630 * Let the tty clear the flip buff to make room.
631 */ 631 */
632 poll_mask |= HVC_POLL_READ; 632 poll_mask |= HVC_POLL_READ;
633 } 633 }
634 break; 634 break;
635 } 635 }
636 for (i = 0; i < n; ++i) { 636 for (i = 0; i < n; ++i) {
637 #ifdef CONFIG_MAGIC_SYSRQ 637 #ifdef CONFIG_MAGIC_SYSRQ
638 if (hp->index == hvc_con_driver.index) { 638 if (hp->index == hvc_con_driver.index) {
639 /* Handle the SysRq Hack */ 639 /* Handle the SysRq Hack */
640 /* XXX should support a sequence */ 640 /* XXX should support a sequence */
641 if (buf[i] == '\x0f') { /* ^O */ 641 if (buf[i] == '\x0f') { /* ^O */
642 /* if ^O is pressed again, reset 642 /* if ^O is pressed again, reset
643 * sysrq_pressed and flip ^O char */ 643 * sysrq_pressed and flip ^O char */
644 sysrq_pressed = !sysrq_pressed; 644 sysrq_pressed = !sysrq_pressed;
645 if (sysrq_pressed) 645 if (sysrq_pressed)
646 continue; 646 continue;
647 } else if (sysrq_pressed) { 647 } else if (sysrq_pressed) {
648 handle_sysrq(buf[i], tty); 648 handle_sysrq(buf[i], tty);
649 sysrq_pressed = 0; 649 sysrq_pressed = 0;
650 continue; 650 continue;
651 } 651 }
652 } 652 }
653 #endif /* CONFIG_MAGIC_SYSRQ */ 653 #endif /* CONFIG_MAGIC_SYSRQ */
654 tty_insert_flip_char(tty, buf[i], 0); 654 tty_insert_flip_char(tty, buf[i], 0);
655 } 655 }
656 656
657 read_total += n; 657 read_total += n;
658 } 658 }
659 throttled: 659 throttled:
660 /* Wakeup write queue if necessary */ 660 /* Wakeup write queue if necessary */
661 if (hp->do_wakeup) { 661 if (hp->do_wakeup) {
662 hp->do_wakeup = 0; 662 hp->do_wakeup = 0;
663 tty_wakeup(tty); 663 tty_wakeup(tty);
664 } 664 }
665 bail: 665 bail:
666 spin_unlock_irqrestore(&hp->lock, flags); 666 spin_unlock_irqrestore(&hp->lock, flags);
667 667
668 if (read_total) { 668 if (read_total) {
669 /* Activity is occurring, so reset the polling backoff value to 669 /* Activity is occurring, so reset the polling backoff value to
670 a minimum for performance. */ 670 a minimum for performance. */
671 timeout = MIN_TIMEOUT; 671 timeout = MIN_TIMEOUT;
672 672
673 tty_flip_buffer_push(tty); 673 tty_flip_buffer_push(tty);
674 } 674 }
675 675
676 return poll_mask; 676 return poll_mask;
677 } 677 }
678 EXPORT_SYMBOL_GPL(hvc_poll); 678 EXPORT_SYMBOL_GPL(hvc_poll);
679 679
680 /** 680 /**
681 * __hvc_resize() - Update terminal window size information. 681 * __hvc_resize() - Update terminal window size information.
682 * @hp: HVC console pointer 682 * @hp: HVC console pointer
683 * @ws: Terminal window size structure 683 * @ws: Terminal window size structure
684 * 684 *
685 * Stores the specified window size information in the hvc structure of @hp. 685 * Stores the specified window size information in the hvc structure of @hp.
686 * The function schedule the tty resize update. 686 * The function schedule the tty resize update.
687 * 687 *
688 * Locking: Locking free; the function MUST be called holding hp->lock 688 * Locking: Locking free; the function MUST be called holding hp->lock
689 */ 689 */
690 void __hvc_resize(struct hvc_struct *hp, struct winsize ws) 690 void __hvc_resize(struct hvc_struct *hp, struct winsize ws)
691 { 691 {
692 hp->ws = ws; 692 hp->ws = ws;
693 schedule_work(&hp->tty_resize); 693 schedule_work(&hp->tty_resize);
694 } 694 }
695 EXPORT_SYMBOL_GPL(__hvc_resize); 695 EXPORT_SYMBOL_GPL(__hvc_resize);
696 696
697 /* 697 /*
698 * This kthread is either polling or interrupt driven. This is determined by 698 * This kthread is either polling or interrupt driven. This is determined by
699 * calling hvc_poll() who determines whether a console adapter support 699 * calling hvc_poll() who determines whether a console adapter support
700 * interrupts. 700 * interrupts.
701 */ 701 */
702 static int khvcd(void *unused) 702 static int khvcd(void *unused)
703 { 703 {
704 int poll_mask; 704 int poll_mask;
705 struct hvc_struct *hp; 705 struct hvc_struct *hp;
706 706
707 set_freezable(); 707 set_freezable();
708 __set_current_state(TASK_RUNNING); 708 __set_current_state(TASK_RUNNING);
709 do { 709 do {
710 poll_mask = 0; 710 poll_mask = 0;
711 hvc_kicked = 0; 711 hvc_kicked = 0;
712 try_to_freeze(); 712 try_to_freeze();
713 wmb(); 713 wmb();
714 if (!cpus_are_in_xmon()) { 714 if (!cpus_are_in_xmon()) {
715 spin_lock(&hvc_structs_lock); 715 spin_lock(&hvc_structs_lock);
716 list_for_each_entry(hp, &hvc_structs, next) { 716 list_for_each_entry(hp, &hvc_structs, next) {
717 poll_mask |= hvc_poll(hp); 717 poll_mask |= hvc_poll(hp);
718 } 718 }
719 spin_unlock(&hvc_structs_lock); 719 spin_unlock(&hvc_structs_lock);
720 } else 720 } else
721 poll_mask |= HVC_POLL_READ; 721 poll_mask |= HVC_POLL_READ;
722 if (hvc_kicked) 722 if (hvc_kicked)
723 continue; 723 continue;
724 set_current_state(TASK_INTERRUPTIBLE); 724 set_current_state(TASK_INTERRUPTIBLE);
725 if (!hvc_kicked) { 725 if (!hvc_kicked) {
726 if (poll_mask == 0) 726 if (poll_mask == 0)
727 schedule(); 727 schedule();
728 else { 728 else {
729 if (timeout < MAX_TIMEOUT) 729 if (timeout < MAX_TIMEOUT)
730 timeout += (timeout >> 6) + 1; 730 timeout += (timeout >> 6) + 1;
731 731
732 msleep_interruptible(timeout); 732 msleep_interruptible(timeout);
733 } 733 }
734 } 734 }
735 __set_current_state(TASK_RUNNING); 735 __set_current_state(TASK_RUNNING);
736 } while (!kthread_should_stop()); 736 } while (!kthread_should_stop());
737 737
738 return 0; 738 return 0;
739 } 739 }
740 740
741 static const struct tty_operations hvc_ops = { 741 static const struct tty_operations hvc_ops = {
742 .open = hvc_open, 742 .open = hvc_open,
743 .close = hvc_close, 743 .close = hvc_close,
744 .write = hvc_write, 744 .write = hvc_write,
745 .hangup = hvc_hangup, 745 .hangup = hvc_hangup,
746 .unthrottle = hvc_unthrottle, 746 .unthrottle = hvc_unthrottle,
747 .write_room = hvc_write_room, 747 .write_room = hvc_write_room,
748 .chars_in_buffer = hvc_chars_in_buffer, 748 .chars_in_buffer = hvc_chars_in_buffer,
749 }; 749 };
750 750
751 struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int data, 751 struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int data,
752 struct hv_ops *ops, int outbuf_size) 752 struct hv_ops *ops, int outbuf_size)
753 { 753 {
754 struct hvc_struct *hp; 754 struct hvc_struct *hp;
755 int i; 755 int i;
756 756
757 /* We wait until a driver actually comes along */ 757 /* We wait until a driver actually comes along */
758 if (!hvc_driver) { 758 if (!hvc_driver) {
759 int err = hvc_init(); 759 int err = hvc_init();
760 if (err) 760 if (err)
761 return ERR_PTR(err); 761 return ERR_PTR(err);
762 } 762 }
763 763
764 hp = kzalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size, 764 hp = kzalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size,
765 GFP_KERNEL); 765 GFP_KERNEL);
766 if (!hp) 766 if (!hp)
767 return ERR_PTR(-ENOMEM); 767 return ERR_PTR(-ENOMEM);
768 768
769 hp->vtermno = vtermno; 769 hp->vtermno = vtermno;
770 hp->data = data; 770 hp->data = data;
771 hp->ops = ops; 771 hp->ops = ops;
772 hp->outbuf_size = outbuf_size; 772 hp->outbuf_size = outbuf_size;
773 hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))]; 773 hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))];
774 774
775 kref_init(&hp->kref); 775 kref_init(&hp->kref);
776 776
777 INIT_WORK(&hp->tty_resize, hvc_set_winsz); 777 INIT_WORK(&hp->tty_resize, hvc_set_winsz);
778 spin_lock_init(&hp->lock); 778 spin_lock_init(&hp->lock);
779 spin_lock(&hvc_structs_lock); 779 spin_lock(&hvc_structs_lock);
780 780
781 /* 781 /*
782 * find index to use: 782 * find index to use:
783 * see if this vterm id matches one registered for console. 783 * see if this vterm id matches one registered for console.
784 */ 784 */
785 for (i=0; i < MAX_NR_HVC_CONSOLES; i++) 785 for (i=0; i < MAX_NR_HVC_CONSOLES; i++)
786 if (vtermnos[i] == hp->vtermno && 786 if (vtermnos[i] == hp->vtermno &&
787 cons_ops[i] == hp->ops) 787 cons_ops[i] == hp->ops)
788 break; 788 break;
789 789
790 /* no matching slot, just use a counter */ 790 /* no matching slot, just use a counter */
791 if (i >= MAX_NR_HVC_CONSOLES) 791 if (i >= MAX_NR_HVC_CONSOLES)
792 i = ++last_hvc; 792 i = ++last_hvc;
793 793
794 hp->index = i; 794 hp->index = i;
795 795
796 list_add_tail(&(hp->next), &hvc_structs); 796 list_add_tail(&(hp->next), &hvc_structs);
797 spin_unlock(&hvc_structs_lock); 797 spin_unlock(&hvc_structs_lock);
798 798
799 return hp; 799 return hp;
800 } 800 }
801 EXPORT_SYMBOL_GPL(hvc_alloc); 801 EXPORT_SYMBOL_GPL(hvc_alloc);
802 802
803 int hvc_remove(struct hvc_struct *hp) 803 int hvc_remove(struct hvc_struct *hp)
804 { 804 {
805 unsigned long flags; 805 unsigned long flags;
806 struct tty_struct *tty; 806 struct tty_struct *tty;
807 807
808 spin_lock_irqsave(&hp->lock, flags); 808 spin_lock_irqsave(&hp->lock, flags);
809 tty = hp->tty; 809 tty = hp->tty;
810 810
811 if (hp->index < MAX_NR_HVC_CONSOLES) 811 if (hp->index < MAX_NR_HVC_CONSOLES)
812 vtermnos[hp->index] = -1; 812 vtermnos[hp->index] = -1;
813 813
814 /* Don't whack hp->irq because tty_hangup() will need to free the irq. */ 814 /* Don't whack hp->irq because tty_hangup() will need to free the irq. */
815 815
816 spin_unlock_irqrestore(&hp->lock, flags); 816 spin_unlock_irqrestore(&hp->lock, flags);
817 817
818 /* 818 /*
819 * We 'put' the instance that was grabbed when the kref instance 819 * We 'put' the instance that was grabbed when the kref instance
820 * was initialized using kref_init(). Let the last holder of this 820 * was initialized using kref_init(). Let the last holder of this
821 * kref cause it to be removed, which will probably be the tty_hangup 821 * kref cause it to be removed, which will probably be the tty_hangup
822 * below. 822 * below.
823 */ 823 */
824 kref_put(&hp->kref, destroy_hvc_struct); 824 kref_put(&hp->kref, destroy_hvc_struct);
825 825
826 /* 826 /*
827 * This function call will auto chain call hvc_hangup. The tty should 827 * This function call will auto chain call hvc_hangup. The tty should
828 * always be valid at this time unless a simultaneous tty close already 828 * always be valid at this time unless a simultaneous tty close already
829 * cleaned up the hvc_struct. 829 * cleaned up the hvc_struct.
830 */ 830 */
831 if (tty) 831 if (tty)
832 tty_hangup(tty); 832 tty_hangup(tty);
833 return 0; 833 return 0;
834 } 834 }
835 EXPORT_SYMBOL_GPL(hvc_remove);
835 836
836 /* Driver initialization: called as soon as someone uses hvc_alloc(). */ 837 /* Driver initialization: called as soon as someone uses hvc_alloc(). */
837 static int hvc_init(void) 838 static int hvc_init(void)
838 { 839 {
839 struct tty_driver *drv; 840 struct tty_driver *drv;
840 int err; 841 int err;
841 842
842 /* We need more than hvc_count adapters due to hotplug additions. */ 843 /* We need more than hvc_count adapters due to hotplug additions. */
843 drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS); 844 drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS);
844 if (!drv) { 845 if (!drv) {
845 err = -ENOMEM; 846 err = -ENOMEM;
846 goto out; 847 goto out;
847 } 848 }
848 849
849 drv->owner = THIS_MODULE; 850 drv->owner = THIS_MODULE;
850 drv->driver_name = "hvc"; 851 drv->driver_name = "hvc";
851 drv->name = "hvc"; 852 drv->name = "hvc";
852 drv->major = HVC_MAJOR; 853 drv->major = HVC_MAJOR;
853 drv->minor_start = HVC_MINOR; 854 drv->minor_start = HVC_MINOR;
854 drv->type = TTY_DRIVER_TYPE_SYSTEM; 855 drv->type = TTY_DRIVER_TYPE_SYSTEM;
855 drv->init_termios = tty_std_termios; 856 drv->init_termios = tty_std_termios;
856 drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS; 857 drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
857 tty_set_operations(drv, &hvc_ops); 858 tty_set_operations(drv, &hvc_ops);
858 859
859 /* Always start the kthread because there can be hotplug vty adapters 860 /* Always start the kthread because there can be hotplug vty adapters
860 * added later. */ 861 * added later. */
861 hvc_task = kthread_run(khvcd, NULL, "khvcd"); 862 hvc_task = kthread_run(khvcd, NULL, "khvcd");
862 if (IS_ERR(hvc_task)) { 863 if (IS_ERR(hvc_task)) {
863 printk(KERN_ERR "Couldn't create kthread for console.\n"); 864 printk(KERN_ERR "Couldn't create kthread for console.\n");
864 err = PTR_ERR(hvc_task); 865 err = PTR_ERR(hvc_task);
865 goto put_tty; 866 goto put_tty;
866 } 867 }
867 868
868 err = tty_register_driver(drv); 869 err = tty_register_driver(drv);
869 if (err) { 870 if (err) {
870 printk(KERN_ERR "Couldn't register hvc console driver\n"); 871 printk(KERN_ERR "Couldn't register hvc console driver\n");
871 goto stop_thread; 872 goto stop_thread;
872 } 873 }
873 874
874 /* 875 /*
875 * Make sure tty is fully registered before allowing it to be 876 * Make sure tty is fully registered before allowing it to be
876 * found by hvc_console_device. 877 * found by hvc_console_device.
877 */ 878 */
878 smp_mb(); 879 smp_mb();
879 hvc_driver = drv; 880 hvc_driver = drv;
880 return 0; 881 return 0;
881 882
882 stop_thread: 883 stop_thread:
883 kthread_stop(hvc_task); 884 kthread_stop(hvc_task);
884 hvc_task = NULL; 885 hvc_task = NULL;
885 put_tty: 886 put_tty:
886 put_tty_driver(drv); 887 put_tty_driver(drv);
887 out: 888 out:
888 return err; 889 return err;
889 } 890 }
890 891
891 /* This isn't particularly necessary due to this being a console driver 892 /* This isn't particularly necessary due to this being a console driver
892 * but it is nice to be thorough. 893 * but it is nice to be thorough.
893 */ 894 */
894 static void __exit hvc_exit(void) 895 static void __exit hvc_exit(void)
895 { 896 {
896 if (hvc_driver) { 897 if (hvc_driver) {
897 kthread_stop(hvc_task); 898 kthread_stop(hvc_task);
898 899
899 tty_unregister_driver(hvc_driver); 900 tty_unregister_driver(hvc_driver);
900 /* return tty_struct instances allocated in hvc_init(). */ 901 /* return tty_struct instances allocated in hvc_init(). */
901 put_tty_driver(hvc_driver); 902 put_tty_driver(hvc_driver);
902 unregister_console(&hvc_con_driver); 903 unregister_console(&hvc_con_driver);
903 } 904 }
904 } 905 }
905 module_exit(hvc_exit); 906 module_exit(hvc_exit);
906 907