Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2001 Anton Blanchard <anton@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. |
| 5 | * Copyright (C) 2004 IBM Corporation |
| 6 | * |
| 7 | * Additional Author(s): |
| 8 | * Ryan S. Arnold <rsa@us.ibm.com> |
| 9 | * |
| 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 |
| 12 | * the Free Software Foundation; either version 2 of the License, or |
| 13 | * (at your option) any later version. |
| 14 | * |
| 15 | * This program is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | * GNU General Public License for more details. |
| 19 | * |
| 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 |
| 22 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 23 | */ |
| 24 | |
| 25 | #include <linux/console.h> |
| 26 | #include <linux/cpumask.h> |
| 27 | #include <linux/init.h> |
| 28 | #include <linux/kbd_kern.h> |
| 29 | #include <linux/kernel.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | #include <linux/kthread.h> |
| 31 | #include <linux/list.h> |
| 32 | #include <linux/module.h> |
| 33 | #include <linux/major.h> |
| 34 | #include <linux/sysrq.h> |
| 35 | #include <linux/tty.h> |
| 36 | #include <linux/tty_flip.h> |
| 37 | #include <linux/sched.h> |
| 38 | #include <linux/spinlock.h> |
| 39 | #include <linux/delay.h> |
Nigel Cunningham | 7dfb710 | 2006-12-06 20:34:23 -0800 | [diff] [blame] | 40 | #include <linux/freezer.h> |
Ryan S. Arnold | 45d607e | 2006-03-27 21:25:16 +0200 | [diff] [blame] | 41 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | #include <asm/uaccess.h> |
Ryan S. Arnold | 45d607e | 2006-03-27 21:25:16 +0200 | [diff] [blame] | 43 | |
| 44 | #include "hvc_console.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | |
| 46 | #define HVC_MAJOR 229 |
| 47 | #define HVC_MINOR 0 |
| 48 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | /* |
| 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. |
| 52 | */ |
| 53 | #define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */ |
| 54 | |
| 55 | /* |
Ryan S. Arnold | 45d607e | 2006-03-27 21:25:16 +0200 | [diff] [blame] | 56 | * These sizes are most efficient for vio, because they are the |
| 57 | * native transfer size. We could make them selectable in the |
| 58 | * future to better deal with backends that want other buffer sizes. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | #define N_OUTBUF 16 |
| 61 | #define N_INBUF 16 |
| 62 | |
Ryan S. Arnold | 45d607e | 2006-03-27 21:25:16 +0200 | [diff] [blame] | 63 | #define __ALIGNED__ __attribute__((__aligned__(sizeof(long)))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 65 | static struct tty_driver *hvc_driver; |
| 66 | static struct task_struct *hvc_task; |
| 67 | |
| 68 | /* Picks up late kicks after list walk but before schedule() */ |
| 69 | static int hvc_kicked; |
| 70 | |
Rusty Russell | 3e6c6f6 | 2007-10-16 23:30:13 -0700 | [diff] [blame] | 71 | static int hvc_init(void); |
| 72 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 73 | #ifdef CONFIG_MAGIC_SYSRQ |
| 74 | static int sysrq_pressed; |
| 75 | #endif |
| 76 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | /* dynamic list of hvc_struct instances */ |
Denis Cheng | bed9759 | 2008-02-06 01:37:35 -0800 | [diff] [blame] | 78 | static LIST_HEAD(hvc_structs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
| 80 | /* |
| 81 | * Protect the list of hvc_struct instances from inserts and removals during |
| 82 | * list traversal. |
| 83 | */ |
| 84 | static DEFINE_SPINLOCK(hvc_structs_lock); |
| 85 | |
| 86 | /* |
Milton Miller | 6f24808 | 2005-07-07 17:56:17 -0700 | [diff] [blame] | 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 |
will schmidt | c3ea692 | 2007-04-18 00:54:51 +1000 | [diff] [blame] | 89 | * a console candidate registered with hvc_instantiate(). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | */ |
Milton Miller | 6f24808 | 2005-07-07 17:56:17 -0700 | [diff] [blame] | 91 | static int last_hvc = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | /* |
will schmidt | c3ea692 | 2007-04-18 00:54:51 +1000 | [diff] [blame] | 94 | * Do not call this function with either the hvc_structs_lock or the hvc_struct |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 95 | * lock held. If successful, this function increments the kref reference |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | * count against the target hvc_struct so it should be released when finished. |
| 97 | */ |
Adrian Bunk | 4fa156e | 2007-05-08 00:24:24 -0700 | [diff] [blame] | 98 | static struct hvc_struct *hvc_get_by_index(int index) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | { |
| 100 | struct hvc_struct *hp; |
| 101 | unsigned long flags; |
| 102 | |
| 103 | spin_lock(&hvc_structs_lock); |
| 104 | |
| 105 | list_for_each_entry(hp, &hvc_structs, next) { |
| 106 | spin_lock_irqsave(&hp->lock, flags); |
| 107 | if (hp->index == index) { |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 108 | kref_get(&hp->kref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | spin_unlock_irqrestore(&hp->lock, flags); |
| 110 | spin_unlock(&hvc_structs_lock); |
| 111 | return hp; |
| 112 | } |
| 113 | spin_unlock_irqrestore(&hp->lock, flags); |
| 114 | } |
| 115 | hp = NULL; |
| 116 | |
| 117 | spin_unlock(&hvc_structs_lock); |
| 118 | return hp; |
| 119 | } |
| 120 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 121 | |
| 122 | /* |
| 123 | * Initial console vtermnos for console API usage prior to full console |
| 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 |
| 126 | * static because kmalloc will not work during early console init. |
| 127 | */ |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 128 | static struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES]; |
Milton Miller | 64e4da5 | 2005-07-07 17:56:22 -0700 | [diff] [blame] | 129 | static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] = |
| 130 | {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1}; |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 131 | |
| 132 | /* |
| 133 | * Console APIs, NOT TTY. These APIs are available immediately when |
| 134 | * hvc_console_setup() finds adapters. |
| 135 | */ |
| 136 | |
Adrian Bunk | 4fa156e | 2007-05-08 00:24:24 -0700 | [diff] [blame] | 137 | static void hvc_console_print(struct console *co, const char *b, |
| 138 | unsigned count) |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 139 | { |
Ryan S. Arnold | 45d607e | 2006-03-27 21:25:16 +0200 | [diff] [blame] | 140 | char c[N_OUTBUF] __ALIGNED__; |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 141 | unsigned i = 0, n = 0; |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 142 | int r, donecr = 0, index = co->index; |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 143 | |
| 144 | /* Console access attempt outside of acceptable console range. */ |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 145 | if (index >= MAX_NR_HVC_CONSOLES) |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 146 | return; |
| 147 | |
will schmidt | c3ea692 | 2007-04-18 00:54:51 +1000 | [diff] [blame] | 148 | /* This console adapter was removed so it is not usable. */ |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 149 | if (vtermnos[index] < 0) |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 150 | return; |
| 151 | |
| 152 | while (count > 0 || i > 0) { |
| 153 | if (count > 0 && i < sizeof(c)) { |
| 154 | if (b[n] == '\n' && !donecr) { |
| 155 | c[i++] = '\r'; |
| 156 | donecr = 1; |
| 157 | } else { |
| 158 | c[i++] = b[n++]; |
| 159 | donecr = 0; |
| 160 | --count; |
| 161 | } |
| 162 | } else { |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 163 | r = cons_ops[index]->put_chars(vtermnos[index], c, i); |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 164 | if (r < 0) { |
| 165 | /* throw away chars on error */ |
| 166 | i = 0; |
| 167 | } else if (r > 0) { |
| 168 | i -= r; |
| 169 | if (i > 0) |
| 170 | memmove(c, c+r, i); |
| 171 | } |
| 172 | } |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | static struct tty_driver *hvc_console_device(struct console *c, int *index) |
| 177 | { |
Milton Miller | 7805b1b | 2005-07-07 17:56:23 -0700 | [diff] [blame] | 178 | if (vtermnos[c->index] == -1) |
| 179 | return NULL; |
| 180 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 181 | *index = c->index; |
| 182 | return hvc_driver; |
| 183 | } |
| 184 | |
| 185 | static int __init hvc_console_setup(struct console *co, char *options) |
| 186 | { |
Milton Miller | 7805b1b | 2005-07-07 17:56:23 -0700 | [diff] [blame] | 187 | if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES) |
| 188 | return -ENODEV; |
| 189 | |
| 190 | if (vtermnos[co->index] == -1) |
| 191 | return -ENODEV; |
| 192 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 193 | return 0; |
| 194 | } |
| 195 | |
Adrian Bunk | 4fa156e | 2007-05-08 00:24:24 -0700 | [diff] [blame] | 196 | static struct console hvc_con_driver = { |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 197 | .name = "hvc", |
| 198 | .write = hvc_console_print, |
| 199 | .device = hvc_console_device, |
| 200 | .setup = hvc_console_setup, |
| 201 | .flags = CON_PRINTBUFFER, |
| 202 | .index = -1, |
| 203 | }; |
| 204 | |
Milton Miller | d5ee257 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 205 | /* |
will schmidt | c3ea692 | 2007-04-18 00:54:51 +1000 | [diff] [blame] | 206 | * Early console initialization. Precedes driver initialization. |
Milton Miller | d5ee257 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 207 | * |
| 208 | * (1) we are first, and the user specified another driver |
| 209 | * -- index will remain -1 |
| 210 | * (2) we are first and the user specified no driver |
| 211 | * -- index will be set to 0, then we will fail setup. |
| 212 | * (3) we are first and the user specified our driver |
| 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 |
| 215 | * -- if the user didn't specify a driver then the console will match |
| 216 | * |
| 217 | * Note that for cases 2 and 3, we will match later when the io driver |
| 218 | * calls hvc_instantiate() and call register again. |
| 219 | */ |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 220 | static int __init hvc_console_init(void) |
| 221 | { |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 222 | register_console(&hvc_con_driver); |
| 223 | return 0; |
| 224 | } |
| 225 | console_initcall(hvc_console_init); |
| 226 | |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 227 | /* callback when the kboject ref count reaches zero. */ |
| 228 | static void destroy_hvc_struct(struct kref *kref) |
| 229 | { |
| 230 | struct hvc_struct *hp = container_of(kref, struct hvc_struct, kref); |
| 231 | unsigned long flags; |
| 232 | |
| 233 | spin_lock(&hvc_structs_lock); |
| 234 | |
| 235 | spin_lock_irqsave(&hp->lock, flags); |
| 236 | list_del(&(hp->next)); |
| 237 | spin_unlock_irqrestore(&hp->lock, flags); |
| 238 | |
| 239 | spin_unlock(&hvc_structs_lock); |
| 240 | |
| 241 | kfree(hp); |
| 242 | } |
| 243 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 244 | /* |
Milton Miller | 6f24808 | 2005-07-07 17:56:17 -0700 | [diff] [blame] | 245 | * hvc_instantiate() is an early console discovery method which locates |
| 246 | * consoles * prior to the vio subsystem discovering them. Hotplugged |
| 247 | * vty adapters do NOT get an hvc_instantiate() callback since they |
| 248 | * appear after early console init. |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 249 | */ |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 250 | int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops) |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 251 | { |
Milton Miller | 7805b1b | 2005-07-07 17:56:23 -0700 | [diff] [blame] | 252 | struct hvc_struct *hp; |
| 253 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 254 | if (index < 0 || index >= MAX_NR_HVC_CONSOLES) |
| 255 | return -1; |
| 256 | |
| 257 | if (vtermnos[index] != -1) |
| 258 | return -1; |
| 259 | |
will schmidt | c3ea692 | 2007-04-18 00:54:51 +1000 | [diff] [blame] | 260 | /* make sure no no tty has been registered in this index */ |
Milton Miller | 7805b1b | 2005-07-07 17:56:23 -0700 | [diff] [blame] | 261 | hp = hvc_get_by_index(index); |
| 262 | if (hp) { |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 263 | kref_put(&hp->kref, destroy_hvc_struct); |
Milton Miller | 7805b1b | 2005-07-07 17:56:23 -0700 | [diff] [blame] | 264 | return -1; |
| 265 | } |
| 266 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 267 | vtermnos[index] = vtermno; |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 268 | cons_ops[index] = ops; |
Milton Miller | 6f24808 | 2005-07-07 17:56:17 -0700 | [diff] [blame] | 269 | |
will schmidt | c3ea692 | 2007-04-18 00:54:51 +1000 | [diff] [blame] | 270 | /* reserve all indices up to and including this index */ |
Milton Miller | 6f24808 | 2005-07-07 17:56:17 -0700 | [diff] [blame] | 271 | if (last_hvc < index) |
| 272 | last_hvc = index; |
| 273 | |
Milton Miller | d5ee257 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 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 |
| 276 | * call register again if previously .setup failed. |
| 277 | */ |
| 278 | if (index == hvc_con_driver.index) |
| 279 | register_console(&hvc_con_driver); |
| 280 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 281 | return 0; |
| 282 | } |
Christian Borntraeger | 7721c49 | 2008-07-25 12:06:06 -0500 | [diff] [blame] | 283 | EXPORT_SYMBOL_GPL(hvc_instantiate); |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 284 | |
| 285 | /* Wake the sleeping khvcd */ |
Christian Borntraeger | 611e097 | 2008-06-20 15:24:08 +0200 | [diff] [blame] | 286 | void hvc_kick(void) |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 287 | { |
| 288 | hvc_kicked = 1; |
| 289 | wake_up_process(hvc_task); |
| 290 | } |
Christian Borntraeger | 7721c49 | 2008-07-25 12:06:06 -0500 | [diff] [blame] | 291 | EXPORT_SYMBOL_GPL(hvc_kick); |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 292 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 293 | static void hvc_unthrottle(struct tty_struct *tty) |
| 294 | { |
| 295 | hvc_kick(); |
| 296 | } |
| 297 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | /* |
| 299 | * The TTY interface won't be used until after the vio layer has exposed the vty |
| 300 | * adapter to the kernel. |
| 301 | */ |
| 302 | static int hvc_open(struct tty_struct *tty, struct file * filp) |
| 303 | { |
| 304 | struct hvc_struct *hp; |
| 305 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 306 | int rc = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 308 | /* Auto increments kref reference if found. */ |
Olof Johansson | 87fd772 | 2006-09-07 15:18:08 -0500 | [diff] [blame] | 309 | if (!(hp = hvc_get_by_index(tty->index))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | return -ENODEV; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | |
| 312 | spin_lock_irqsave(&hp->lock, flags); |
| 313 | /* Check and then increment for fast path open. */ |
| 314 | if (hp->count++ > 0) { |
| 315 | spin_unlock_irqrestore(&hp->lock, flags); |
| 316 | hvc_kick(); |
| 317 | return 0; |
| 318 | } /* else count == 0 */ |
| 319 | |
| 320 | tty->driver_data = hp; |
Michal Ostrowski | fb5c594 | 2006-02-18 09:29:59 -0500 | [diff] [blame] | 321 | tty->low_latency = 1; /* Makes flushes to ldisc synchronous. */ |
| 322 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | hp->tty = tty; |
Christian Borntraeger | 611e097 | 2008-06-20 15:24:08 +0200 | [diff] [blame] | 324 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | spin_unlock_irqrestore(&hp->lock, flags); |
Christian Borntraeger | 611e097 | 2008-06-20 15:24:08 +0200 | [diff] [blame] | 326 | |
Christian Borntraeger | b1b135c | 2008-08-07 09:18:34 +0200 | [diff] [blame] | 327 | if (hp->ops->notifier_add) |
| 328 | rc = hp->ops->notifier_add(hp, hp->data); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | |
| 330 | /* |
Christian Borntraeger | 611e097 | 2008-06-20 15:24:08 +0200 | [diff] [blame] | 331 | * If the notifier fails we return an error. The tty layer |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | * will call hvc_close() after a failed open but we don't want to clean |
| 333 | * up there so we'll clean up here and clear out the previously set |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 334 | * tty fields and return the kref reference. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | */ |
| 336 | if (rc) { |
| 337 | spin_lock_irqsave(&hp->lock, flags); |
| 338 | hp->tty = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | spin_unlock_irqrestore(&hp->lock, flags); |
| 340 | tty->driver_data = NULL; |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 341 | kref_put(&hp->kref, destroy_hvc_struct); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc); |
| 343 | } |
| 344 | /* Force wakeup of the polling thread */ |
| 345 | hvc_kick(); |
| 346 | |
| 347 | return rc; |
| 348 | } |
| 349 | |
| 350 | static void hvc_close(struct tty_struct *tty, struct file * filp) |
| 351 | { |
| 352 | struct hvc_struct *hp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | unsigned long flags; |
| 354 | |
| 355 | if (tty_hung_up_p(filp)) |
| 356 | return; |
| 357 | |
| 358 | /* |
| 359 | * No driver_data means that this close was issued after a failed |
| 360 | * hvc_open by the tty layer's release_dev() function and we can just |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 361 | * exit cleanly because the kref reference wasn't made. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | */ |
| 363 | if (!tty->driver_data) |
| 364 | return; |
| 365 | |
| 366 | hp = tty->driver_data; |
| 367 | spin_lock_irqsave(&hp->lock, flags); |
| 368 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | if (--hp->count == 0) { |
Christian Borntraeger | 611e097 | 2008-06-20 15:24:08 +0200 | [diff] [blame] | 370 | if (hp->ops->notifier_del) |
| 371 | hp->ops->notifier_del(hp, hp->data); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | |
| 373 | /* We are done with the tty pointer now. */ |
| 374 | hp->tty = NULL; |
| 375 | spin_unlock_irqrestore(&hp->lock, flags); |
| 376 | |
| 377 | /* |
| 378 | * Chain calls chars_in_buffer() and returns immediately if |
| 379 | * there is no buffered data otherwise sleeps on a wait queue |
| 380 | * waking periodically to check chars_in_buffer(). |
| 381 | */ |
| 382 | tty_wait_until_sent(tty, HVC_CLOSE_WAIT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | } else { |
| 384 | if (hp->count < 0) |
| 385 | printk(KERN_ERR "hvc_close %X: oops, count is %d\n", |
| 386 | hp->vtermno, hp->count); |
| 387 | spin_unlock_irqrestore(&hp->lock, flags); |
| 388 | } |
| 389 | |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 390 | kref_put(&hp->kref, destroy_hvc_struct); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | } |
| 392 | |
| 393 | static void hvc_hangup(struct tty_struct *tty) |
| 394 | { |
| 395 | struct hvc_struct *hp = tty->driver_data; |
| 396 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 397 | int temp_open_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | |
| 399 | if (!hp) |
| 400 | return; |
| 401 | |
| 402 | spin_lock_irqsave(&hp->lock, flags); |
| 403 | |
| 404 | /* |
| 405 | * The N_TTY line discipline has problems such that in a close vs |
| 406 | * open->hangup case this can be called after the final close so prevent |
| 407 | * that from happening for now. |
| 408 | */ |
| 409 | if (hp->count <= 0) { |
| 410 | spin_unlock_irqrestore(&hp->lock, flags); |
| 411 | return; |
| 412 | } |
| 413 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 414 | temp_open_count = hp->count; |
| 415 | hp->count = 0; |
| 416 | hp->n_outbuf = 0; |
| 417 | hp->tty = NULL; |
Christian Borntraeger | 611e097 | 2008-06-20 15:24:08 +0200 | [diff] [blame] | 418 | |
| 419 | if (hp->ops->notifier_del) |
| 420 | hp->ops->notifier_del(hp, hp->data); |
| 421 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 422 | spin_unlock_irqrestore(&hp->lock, flags); |
Christian Borntraeger | 611e097 | 2008-06-20 15:24:08 +0200 | [diff] [blame] | 423 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 424 | while(temp_open_count) { |
| 425 | --temp_open_count; |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 426 | kref_put(&hp->kref, destroy_hvc_struct); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | } |
| 428 | } |
| 429 | |
| 430 | /* |
| 431 | * Push buffered characters whether they were just recently buffered or waiting |
| 432 | * on a blocked hypervisor. Call this function with hp->lock held. |
| 433 | */ |
| 434 | static void hvc_push(struct hvc_struct *hp) |
| 435 | { |
| 436 | int n; |
| 437 | |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 438 | n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | if (n <= 0) { |
Ryan S. Arnold | 45d607e | 2006-03-27 21:25:16 +0200 | [diff] [blame] | 440 | if (n == 0) { |
| 441 | hp->do_wakeup = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | return; |
Ryan S. Arnold | 45d607e | 2006-03-27 21:25:16 +0200 | [diff] [blame] | 443 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 444 | /* throw away output on error; this happens when |
| 445 | there is no session connected to the vterm. */ |
| 446 | hp->n_outbuf = 0; |
| 447 | } else |
| 448 | hp->n_outbuf -= n; |
| 449 | if (hp->n_outbuf > 0) |
| 450 | memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf); |
| 451 | else |
| 452 | hp->do_wakeup = 1; |
| 453 | } |
| 454 | |
Ryan S. Arnold | 45d607e | 2006-03-27 21:25:16 +0200 | [diff] [blame] | 455 | static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | { |
Ryan S. Arnold | 45d607e | 2006-03-27 21:25:16 +0200 | [diff] [blame] | 457 | struct hvc_struct *hp = tty->driver_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | unsigned long flags; |
| 459 | int rsize, written = 0; |
| 460 | |
Ryan S. Arnold | 45d607e | 2006-03-27 21:25:16 +0200 | [diff] [blame] | 461 | /* This write was probably executed during a tty close. */ |
| 462 | if (!hp) |
| 463 | return -EPIPE; |
| 464 | |
| 465 | if (hp->count <= 0) |
| 466 | return -EIO; |
| 467 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | spin_lock_irqsave(&hp->lock, flags); |
| 469 | |
| 470 | /* Push pending writes */ |
| 471 | if (hp->n_outbuf > 0) |
| 472 | hvc_push(hp); |
| 473 | |
Stephen Rothwell | 4e9e95a | 2006-07-13 18:53:32 +1000 | [diff] [blame] | 474 | while (count > 0 && (rsize = hp->outbuf_size - hp->n_outbuf) > 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | if (rsize > count) |
| 476 | rsize = count; |
| 477 | memcpy(hp->outbuf + hp->n_outbuf, buf, rsize); |
| 478 | count -= rsize; |
| 479 | buf += rsize; |
| 480 | hp->n_outbuf += rsize; |
| 481 | written += rsize; |
| 482 | hvc_push(hp); |
| 483 | } |
| 484 | spin_unlock_irqrestore(&hp->lock, flags); |
| 485 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | /* |
| 487 | * Racy, but harmless, kick thread if there is still pending data. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | */ |
| 489 | if (hp->n_outbuf) |
| 490 | hvc_kick(); |
| 491 | |
| 492 | return written; |
| 493 | } |
| 494 | |
| 495 | /* |
| 496 | * This is actually a contract between the driver and the tty layer outlining |
will schmidt | c3ea692 | 2007-04-18 00:54:51 +1000 | [diff] [blame] | 497 | * how much write room the driver can guarantee will be sent OR BUFFERED. This |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | * driver MUST honor the return value. |
| 499 | */ |
| 500 | static int hvc_write_room(struct tty_struct *tty) |
| 501 | { |
| 502 | struct hvc_struct *hp = tty->driver_data; |
| 503 | |
| 504 | if (!hp) |
| 505 | return -1; |
| 506 | |
Stephen Rothwell | 4e9e95a | 2006-07-13 18:53:32 +1000 | [diff] [blame] | 507 | return hp->outbuf_size - hp->n_outbuf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | } |
| 509 | |
| 510 | static int hvc_chars_in_buffer(struct tty_struct *tty) |
| 511 | { |
| 512 | struct hvc_struct *hp = tty->driver_data; |
| 513 | |
| 514 | if (!hp) |
| 515 | return -1; |
| 516 | return hp->n_outbuf; |
| 517 | } |
| 518 | |
Will Schmidt | b791072 | 2007-04-18 00:44:46 +1000 | [diff] [blame] | 519 | /* |
| 520 | * timeout will vary between the MIN and MAX values defined here. By default |
| 521 | * and during console activity we will use a default MIN_TIMEOUT of 10. When |
| 522 | * the console is idle, we increase the timeout value on each pass through |
| 523 | * msleep until we reach the max. This may be noticeable as a brief (average |
| 524 | * one second) delay on the console before the console responds to input when |
| 525 | * there has been no input for some time. |
| 526 | */ |
| 527 | #define MIN_TIMEOUT (10) |
| 528 | #define MAX_TIMEOUT (2000) |
| 529 | static u32 timeout = MIN_TIMEOUT; |
| 530 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | #define HVC_POLL_READ 0x00000001 |
| 532 | #define HVC_POLL_WRITE 0x00000002 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | |
Christian Borntraeger | 611e097 | 2008-06-20 15:24:08 +0200 | [diff] [blame] | 534 | int hvc_poll(struct hvc_struct *hp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | { |
| 536 | struct tty_struct *tty; |
| 537 | int i, n, poll_mask = 0; |
| 538 | char buf[N_INBUF] __ALIGNED__; |
| 539 | unsigned long flags; |
| 540 | int read_total = 0; |
| 541 | |
| 542 | spin_lock_irqsave(&hp->lock, flags); |
| 543 | |
| 544 | /* Push pending writes */ |
| 545 | if (hp->n_outbuf > 0) |
| 546 | hvc_push(hp); |
Michael Ellerman | b537446 | 2006-06-07 17:10:03 +1000 | [diff] [blame] | 547 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | /* Reschedule us if still some write pending */ |
| 549 | if (hp->n_outbuf > 0) |
| 550 | poll_mask |= HVC_POLL_WRITE; |
| 551 | |
| 552 | /* No tty attached, just skip */ |
| 553 | tty = hp->tty; |
| 554 | if (tty == NULL) |
| 555 | goto bail; |
| 556 | |
| 557 | /* Now check if we can get data (are we throttled ?) */ |
| 558 | if (test_bit(TTY_THROTTLED, &tty->flags)) |
| 559 | goto throttled; |
| 560 | |
Christian Borntraeger | 611e097 | 2008-06-20 15:24:08 +0200 | [diff] [blame] | 561 | /* If we aren't notifier driven and aren't throttled, we always |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | * request a reschedule |
| 563 | */ |
Christian Borntraeger | 611e097 | 2008-06-20 15:24:08 +0200 | [diff] [blame] | 564 | if (!hp->irq_requested) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | poll_mask |= HVC_POLL_READ; |
| 566 | |
| 567 | /* Read data if any */ |
| 568 | for (;;) { |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 569 | int count = tty_buffer_request_room(tty, N_INBUF); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | |
| 571 | /* If flip is full, just reschedule a later read */ |
| 572 | if (count == 0) { |
| 573 | poll_mask |= HVC_POLL_READ; |
| 574 | break; |
| 575 | } |
| 576 | |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 577 | n = hp->ops->get_chars(hp->vtermno, buf, count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | if (n <= 0) { |
| 579 | /* Hangup the tty when disconnected from host */ |
| 580 | if (n == -EPIPE) { |
| 581 | spin_unlock_irqrestore(&hp->lock, flags); |
| 582 | tty_hangup(tty); |
| 583 | spin_lock_irqsave(&hp->lock, flags); |
Ryan S. Arnold | 45d607e | 2006-03-27 21:25:16 +0200 | [diff] [blame] | 584 | } else if ( n == -EAGAIN ) { |
| 585 | /* |
| 586 | * Some back-ends can only ensure a certain min |
| 587 | * num of bytes read, which may be > 'count'. |
| 588 | * Let the tty clear the flip buff to make room. |
| 589 | */ |
| 590 | poll_mask |= HVC_POLL_READ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | } |
| 592 | break; |
| 593 | } |
| 594 | for (i = 0; i < n; ++i) { |
| 595 | #ifdef CONFIG_MAGIC_SYSRQ |
Milton Miller | 2b9e0ba | 2005-07-07 17:56:19 -0700 | [diff] [blame] | 596 | if (hp->index == hvc_con_driver.index) { |
| 597 | /* Handle the SysRq Hack */ |
| 598 | /* XXX should support a sequence */ |
| 599 | if (buf[i] == '\x0f') { /* ^O */ |
| 600 | sysrq_pressed = 1; |
| 601 | continue; |
| 602 | } else if (sysrq_pressed) { |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 603 | handle_sysrq(buf[i], tty); |
Milton Miller | 2b9e0ba | 2005-07-07 17:56:19 -0700 | [diff] [blame] | 604 | sysrq_pressed = 0; |
| 605 | continue; |
| 606 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | } |
| 608 | #endif /* CONFIG_MAGIC_SYSRQ */ |
| 609 | tty_insert_flip_char(tty, buf[i], 0); |
| 610 | } |
| 611 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | read_total += n; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | } |
| 614 | throttled: |
| 615 | /* Wakeup write queue if necessary */ |
| 616 | if (hp->do_wakeup) { |
| 617 | hp->do_wakeup = 0; |
| 618 | tty_wakeup(tty); |
| 619 | } |
| 620 | bail: |
| 621 | spin_unlock_irqrestore(&hp->lock, flags); |
| 622 | |
Will Schmidt | b791072 | 2007-04-18 00:44:46 +1000 | [diff] [blame] | 623 | if (read_total) { |
| 624 | /* Activity is occurring, so reset the polling backoff value to |
| 625 | a minimum for performance. */ |
| 626 | timeout = MIN_TIMEOUT; |
| 627 | |
Michal Ostrowski | fb5c594 | 2006-02-18 09:29:59 -0500 | [diff] [blame] | 628 | tty_flip_buffer_push(tty); |
Will Schmidt | b791072 | 2007-04-18 00:44:46 +1000 | [diff] [blame] | 629 | } |
| 630 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | return poll_mask; |
| 632 | } |
Christian Borntraeger | 7721c49 | 2008-07-25 12:06:06 -0500 | [diff] [blame] | 633 | EXPORT_SYMBOL_GPL(hvc_poll); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 634 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 635 | /* |
| 636 | * This kthread is either polling or interrupt driven. This is determined by |
| 637 | * calling hvc_poll() who determines whether a console adapter support |
| 638 | * interrupts. |
| 639 | */ |
Adrian Bunk | 5605d4d | 2007-07-09 11:37:38 -0700 | [diff] [blame] | 640 | static int khvcd(void *unused) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | { |
| 642 | int poll_mask; |
| 643 | struct hvc_struct *hp; |
| 644 | |
Rafael J. Wysocki | 8314418 | 2007-07-17 04:03:35 -0700 | [diff] [blame] | 645 | set_freezable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 646 | __set_current_state(TASK_RUNNING); |
| 647 | do { |
| 648 | poll_mask = 0; |
| 649 | hvc_kicked = 0; |
Andrew Morton | b64074e | 2006-09-16 12:15:38 -0700 | [diff] [blame] | 650 | try_to_freeze(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | wmb(); |
Michael Ellerman | 1c8950f | 2008-05-08 14:27:17 +1000 | [diff] [blame] | 652 | if (!cpus_are_in_xmon()) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | spin_lock(&hvc_structs_lock); |
| 654 | list_for_each_entry(hp, &hvc_structs, next) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | poll_mask |= hvc_poll(hp); |
| 656 | } |
| 657 | spin_unlock(&hvc_structs_lock); |
| 658 | } else |
| 659 | poll_mask |= HVC_POLL_READ; |
| 660 | if (hvc_kicked) |
| 661 | continue; |
Michael Ellerman | b537446 | 2006-06-07 17:10:03 +1000 | [diff] [blame] | 662 | if (poll_mask & HVC_POLL_WRITE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | yield(); |
| 664 | continue; |
| 665 | } |
| 666 | set_current_state(TASK_INTERRUPTIBLE); |
| 667 | if (!hvc_kicked) { |
| 668 | if (poll_mask == 0) |
| 669 | schedule(); |
Will Schmidt | b791072 | 2007-04-18 00:44:46 +1000 | [diff] [blame] | 670 | else { |
| 671 | if (timeout < MAX_TIMEOUT) |
| 672 | timeout += (timeout >> 6) + 1; |
| 673 | |
| 674 | msleep_interruptible(timeout); |
| 675 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 676 | } |
| 677 | __set_current_state(TASK_RUNNING); |
| 678 | } while (!kthread_should_stop()); |
| 679 | |
| 680 | return 0; |
| 681 | } |
| 682 | |
Jeff Dike | b68e31d | 2006-10-02 02:17:18 -0700 | [diff] [blame] | 683 | static const struct tty_operations hvc_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 684 | .open = hvc_open, |
| 685 | .close = hvc_close, |
| 686 | .write = hvc_write, |
| 687 | .hangup = hvc_hangup, |
| 688 | .unthrottle = hvc_unthrottle, |
| 689 | .write_room = hvc_write_room, |
| 690 | .chars_in_buffer = hvc_chars_in_buffer, |
| 691 | }; |
| 692 | |
Christian Borntraeger | 611e097 | 2008-06-20 15:24:08 +0200 | [diff] [blame] | 693 | struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int data, |
Stephen Rothwell | 4e9e95a | 2006-07-13 18:53:32 +1000 | [diff] [blame] | 694 | struct hv_ops *ops, int outbuf_size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | { |
| 696 | struct hvc_struct *hp; |
Milton Miller | 6f24808 | 2005-07-07 17:56:17 -0700 | [diff] [blame] | 697 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | |
Rusty Russell | 3e6c6f6 | 2007-10-16 23:30:13 -0700 | [diff] [blame] | 699 | /* We wait until a driver actually comes along */ |
| 700 | if (!hvc_driver) { |
| 701 | int err = hvc_init(); |
| 702 | if (err) |
| 703 | return ERR_PTR(err); |
| 704 | } |
| 705 | |
Stephen Rothwell | 4e9e95a | 2006-07-13 18:53:32 +1000 | [diff] [blame] | 706 | hp = kmalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size, |
| 707 | GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | if (!hp) |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 709 | return ERR_PTR(-ENOMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 710 | |
| 711 | memset(hp, 0x00, sizeof(*hp)); |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 712 | |
| 713 | hp->vtermno = vtermno; |
Christian Borntraeger | 611e097 | 2008-06-20 15:24:08 +0200 | [diff] [blame] | 714 | hp->data = data; |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 715 | hp->ops = ops; |
Stephen Rothwell | 4e9e95a | 2006-07-13 18:53:32 +1000 | [diff] [blame] | 716 | hp->outbuf_size = outbuf_size; |
| 717 | hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 718 | |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 719 | kref_init(&hp->kref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | |
| 721 | spin_lock_init(&hp->lock); |
| 722 | spin_lock(&hvc_structs_lock); |
Milton Miller | 6f24808 | 2005-07-07 17:56:17 -0700 | [diff] [blame] | 723 | |
| 724 | /* |
| 725 | * find index to use: |
| 726 | * see if this vterm id matches one registered for console. |
| 727 | */ |
| 728 | for (i=0; i < MAX_NR_HVC_CONSOLES; i++) |
Ryan S. Arnold | 45d607e | 2006-03-27 21:25:16 +0200 | [diff] [blame] | 729 | if (vtermnos[i] == hp->vtermno && |
| 730 | cons_ops[i] == hp->ops) |
Milton Miller | 6f24808 | 2005-07-07 17:56:17 -0700 | [diff] [blame] | 731 | break; |
| 732 | |
| 733 | /* no matching slot, just use a counter */ |
| 734 | if (i >= MAX_NR_HVC_CONSOLES) |
| 735 | i = ++last_hvc; |
| 736 | |
| 737 | hp->index = i; |
| 738 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | list_add_tail(&(hp->next), &hvc_structs); |
| 740 | spin_unlock(&hvc_structs_lock); |
| 741 | |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 742 | return hp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | } |
Christian Borntraeger | 7721c49 | 2008-07-25 12:06:06 -0500 | [diff] [blame] | 744 | EXPORT_SYMBOL_GPL(hvc_alloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 746 | int __devexit hvc_remove(struct hvc_struct *hp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 749 | struct tty_struct *tty; |
| 750 | |
| 751 | spin_lock_irqsave(&hp->lock, flags); |
| 752 | tty = hp->tty; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | |
| 754 | if (hp->index < MAX_NR_HVC_CONSOLES) |
| 755 | vtermnos[hp->index] = -1; |
| 756 | |
| 757 | /* Don't whack hp->irq because tty_hangup() will need to free the irq. */ |
| 758 | |
| 759 | spin_unlock_irqrestore(&hp->lock, flags); |
| 760 | |
| 761 | /* |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 762 | * We 'put' the instance that was grabbed when the kref instance |
| 763 | * was initialized using kref_init(). Let the last holder of this |
| 764 | * kref cause it to be removed, which will probably be the tty_hangup |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | * below. |
| 766 | */ |
Greg Kroah-Hartman | 12b20de | 2007-11-28 10:46:22 -0800 | [diff] [blame] | 767 | kref_put(&hp->kref, destroy_hvc_struct); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | |
| 769 | /* |
| 770 | * This function call will auto chain call hvc_hangup. The tty should |
| 771 | * always be valid at this time unless a simultaneous tty close already |
| 772 | * cleaned up the hvc_struct. |
| 773 | */ |
| 774 | if (tty) |
| 775 | tty_hangup(tty); |
| 776 | return 0; |
| 777 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | |
Rusty Russell | 3e6c6f6 | 2007-10-16 23:30:13 -0700 | [diff] [blame] | 779 | /* Driver initialization: called as soon as someone uses hvc_alloc(). */ |
| 780 | static int hvc_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 781 | { |
Michael Neuling | 55aab8c | 2006-03-25 17:30:00 +1100 | [diff] [blame] | 782 | struct tty_driver *drv; |
Rusty Russell | 3e6c6f6 | 2007-10-16 23:30:13 -0700 | [diff] [blame] | 783 | int err; |
Michael Neuling | 55aab8c | 2006-03-25 17:30:00 +1100 | [diff] [blame] | 784 | |
Milton Miller | 5f6d9c0 | 2005-07-07 17:56:21 -0700 | [diff] [blame] | 785 | /* We need more than hvc_count adapters due to hotplug additions. */ |
Michael Neuling | 55aab8c | 2006-03-25 17:30:00 +1100 | [diff] [blame] | 786 | drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS); |
Rusty Russell | 3e6c6f6 | 2007-10-16 23:30:13 -0700 | [diff] [blame] | 787 | if (!drv) { |
| 788 | err = -ENOMEM; |
| 789 | goto out; |
| 790 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 791 | |
Michael Neuling | 55aab8c | 2006-03-25 17:30:00 +1100 | [diff] [blame] | 792 | drv->owner = THIS_MODULE; |
Michael Neuling | 55aab8c | 2006-03-25 17:30:00 +1100 | [diff] [blame] | 793 | drv->driver_name = "hvc"; |
| 794 | drv->name = "hvc"; |
| 795 | drv->major = HVC_MAJOR; |
| 796 | drv->minor_start = HVC_MINOR; |
| 797 | drv->type = TTY_DRIVER_TYPE_SYSTEM; |
| 798 | drv->init_termios = tty_std_termios; |
| 799 | drv->flags = TTY_DRIVER_REAL_RAW; |
| 800 | tty_set_operations(drv, &hvc_ops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 801 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 802 | /* Always start the kthread because there can be hotplug vty adapters |
| 803 | * added later. */ |
| 804 | hvc_task = kthread_run(khvcd, NULL, "khvcd"); |
| 805 | if (IS_ERR(hvc_task)) { |
Rusty Russell | 3e6c6f6 | 2007-10-16 23:30:13 -0700 | [diff] [blame] | 806 | printk(KERN_ERR "Couldn't create kthread for console.\n"); |
| 807 | err = PTR_ERR(hvc_task); |
| 808 | goto put_tty; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 809 | } |
| 810 | |
Rusty Russell | 3e6c6f6 | 2007-10-16 23:30:13 -0700 | [diff] [blame] | 811 | err = tty_register_driver(drv); |
| 812 | if (err) { |
| 813 | printk(KERN_ERR "Couldn't register hvc console driver\n"); |
| 814 | goto stop_thread; |
| 815 | } |
Anton Blanchard | ef4cbee | 2005-09-14 14:19:18 -0700 | [diff] [blame] | 816 | |
Rusty Russell | 3e6c6f6 | 2007-10-16 23:30:13 -0700 | [diff] [blame] | 817 | /* FIXME: This mb() seems completely random. Remove it. */ |
Michael Neuling | 55aab8c | 2006-03-25 17:30:00 +1100 | [diff] [blame] | 818 | mb(); |
| 819 | hvc_driver = drv; |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 820 | return 0; |
Rusty Russell | 3e6c6f6 | 2007-10-16 23:30:13 -0700 | [diff] [blame] | 821 | |
| 822 | put_tty: |
| 823 | put_tty_driver(hvc_driver); |
| 824 | stop_thread: |
| 825 | kthread_stop(hvc_task); |
| 826 | hvc_task = NULL; |
| 827 | out: |
| 828 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | } |
| 830 | |
will schmidt | c3ea692 | 2007-04-18 00:54:51 +1000 | [diff] [blame] | 831 | /* This isn't particularly necessary due to this being a console driver |
Milton Miller | 320da0d | 2005-07-07 17:56:20 -0700 | [diff] [blame] | 832 | * but it is nice to be thorough. |
| 833 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 834 | static void __exit hvc_exit(void) |
| 835 | { |
Rusty Russell | 3e6c6f6 | 2007-10-16 23:30:13 -0700 | [diff] [blame] | 836 | if (hvc_driver) { |
| 837 | kthread_stop(hvc_task); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 838 | |
Rusty Russell | 3e6c6f6 | 2007-10-16 23:30:13 -0700 | [diff] [blame] | 839 | tty_unregister_driver(hvc_driver); |
| 840 | /* return tty_struct instances allocated in hvc_init(). */ |
| 841 | put_tty_driver(hvc_driver); |
| 842 | unregister_console(&hvc_con_driver); |
| 843 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 845 | module_exit(hvc_exit); |