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 | |
Milton Miller | e51d8c9 | 2005-07-07 17:56:21 -0700 | [diff] [blame] | 25 | #include <linux/config.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | #include <linux/console.h> |
| 27 | #include <linux/cpumask.h> |
| 28 | #include <linux/init.h> |
| 29 | #include <linux/kbd_kern.h> |
| 30 | #include <linux/kernel.h> |
| 31 | #include <linux/kobject.h> |
| 32 | #include <linux/kthread.h> |
| 33 | #include <linux/list.h> |
| 34 | #include <linux/module.h> |
| 35 | #include <linux/major.h> |
| 36 | #include <linux/sysrq.h> |
| 37 | #include <linux/tty.h> |
| 38 | #include <linux/tty_flip.h> |
| 39 | #include <linux/sched.h> |
| 40 | #include <linux/spinlock.h> |
| 41 | #include <linux/delay.h> |
| 42 | #include <asm/uaccess.h> |
| 43 | #include <asm/hvconsole.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | |
| 45 | #define HVC_MAJOR 229 |
| 46 | #define HVC_MINOR 0 |
| 47 | |
| 48 | #define TIMEOUT (10) |
| 49 | |
| 50 | /* |
| 51 | * Wait this long per iteration while trying to push buffered data to the |
| 52 | * hypervisor before allowing the tty to complete a close operation. |
| 53 | */ |
| 54 | #define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */ |
| 55 | |
| 56 | /* |
| 57 | * The Linux TTY code does not support dynamic addition of tty derived devices |
| 58 | * so we need to know how many tty devices we might need when space is allocated |
| 59 | * for the tty device. Since this driver supports hotplug of vty adapters we |
| 60 | * need to make sure we have enough allocated. |
| 61 | */ |
| 62 | #define HVC_ALLOC_TTY_ADAPTERS 8 |
| 63 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | #define N_OUTBUF 16 |
| 65 | #define N_INBUF 16 |
| 66 | |
| 67 | #define __ALIGNED__ __attribute__((__aligned__(8))) |
| 68 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 69 | static struct tty_driver *hvc_driver; |
| 70 | static struct task_struct *hvc_task; |
| 71 | |
| 72 | /* Picks up late kicks after list walk but before schedule() */ |
| 73 | static int hvc_kicked; |
| 74 | |
| 75 | #ifdef CONFIG_MAGIC_SYSRQ |
| 76 | static int sysrq_pressed; |
| 77 | #endif |
| 78 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | struct hvc_struct { |
| 80 | spinlock_t lock; |
| 81 | int index; |
| 82 | struct tty_struct *tty; |
| 83 | unsigned int count; |
| 84 | int do_wakeup; |
| 85 | char outbuf[N_OUTBUF] __ALIGNED__; |
| 86 | int n_outbuf; |
| 87 | uint32_t vtermno; |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 88 | struct hv_ops *ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | int irq_requested; |
| 90 | int irq; |
| 91 | struct list_head next; |
| 92 | struct kobject kobj; /* ref count & hvc_struct lifetime */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | }; |
| 94 | |
| 95 | /* dynamic list of hvc_struct instances */ |
| 96 | static struct list_head hvc_structs = LIST_HEAD_INIT(hvc_structs); |
| 97 | |
| 98 | /* |
| 99 | * Protect the list of hvc_struct instances from inserts and removals during |
| 100 | * list traversal. |
| 101 | */ |
| 102 | static DEFINE_SPINLOCK(hvc_structs_lock); |
| 103 | |
| 104 | /* |
Milton Miller | 6f24808 | 2005-07-07 17:56:17 -0700 | [diff] [blame] | 105 | * This value is used to assign a tty->index value to a hvc_struct based |
| 106 | * upon order of exposure via hvc_probe(), when we can not match it to |
| 107 | * a console canidate registered with hvc_instantiate(). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | */ |
Milton Miller | 6f24808 | 2005-07-07 17:56:17 -0700 | [diff] [blame] | 109 | static int last_hvc = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | /* |
| 112 | * Do not call this function with either the hvc_strucst_lock or the hvc_struct |
| 113 | * lock held. If successful, this function increments the kobject reference |
| 114 | * count against the target hvc_struct so it should be released when finished. |
| 115 | */ |
| 116 | struct hvc_struct *hvc_get_by_index(int index) |
| 117 | { |
| 118 | struct hvc_struct *hp; |
| 119 | unsigned long flags; |
| 120 | |
| 121 | spin_lock(&hvc_structs_lock); |
| 122 | |
| 123 | list_for_each_entry(hp, &hvc_structs, next) { |
| 124 | spin_lock_irqsave(&hp->lock, flags); |
| 125 | if (hp->index == index) { |
| 126 | kobject_get(&hp->kobj); |
| 127 | spin_unlock_irqrestore(&hp->lock, flags); |
| 128 | spin_unlock(&hvc_structs_lock); |
| 129 | return hp; |
| 130 | } |
| 131 | spin_unlock_irqrestore(&hp->lock, flags); |
| 132 | } |
| 133 | hp = NULL; |
| 134 | |
| 135 | spin_unlock(&hvc_structs_lock); |
| 136 | return hp; |
| 137 | } |
| 138 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 139 | |
| 140 | /* |
| 141 | * Initial console vtermnos for console API usage prior to full console |
| 142 | * initialization. Any vty adapter outside this range will not have usable |
| 143 | * console interfaces but can still be used as a tty device. This has to be |
| 144 | * static because kmalloc will not work during early console init. |
| 145 | */ |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 146 | static struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES]; |
Milton Miller | 64e4da5 | 2005-07-07 17:56:22 -0700 | [diff] [blame] | 147 | static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] = |
| 148 | {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1}; |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 149 | |
| 150 | /* |
| 151 | * Console APIs, NOT TTY. These APIs are available immediately when |
| 152 | * hvc_console_setup() finds adapters. |
| 153 | */ |
| 154 | |
| 155 | void hvc_console_print(struct console *co, const char *b, unsigned count) |
| 156 | { |
| 157 | char c[16] __ALIGNED__; |
| 158 | unsigned i = 0, n = 0; |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 159 | int r, donecr = 0, index = co->index; |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 160 | |
| 161 | /* Console access attempt outside of acceptable console range. */ |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 162 | if (index >= MAX_NR_HVC_CONSOLES) |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 163 | return; |
| 164 | |
| 165 | /* This console adapter was removed so it is not useable. */ |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 166 | if (vtermnos[index] < 0) |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 167 | return; |
| 168 | |
| 169 | while (count > 0 || i > 0) { |
| 170 | if (count > 0 && i < sizeof(c)) { |
| 171 | if (b[n] == '\n' && !donecr) { |
| 172 | c[i++] = '\r'; |
| 173 | donecr = 1; |
| 174 | } else { |
| 175 | c[i++] = b[n++]; |
| 176 | donecr = 0; |
| 177 | --count; |
| 178 | } |
| 179 | } else { |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 180 | r = cons_ops[index]->put_chars(vtermnos[index], c, i); |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 181 | if (r < 0) { |
| 182 | /* throw away chars on error */ |
| 183 | i = 0; |
| 184 | } else if (r > 0) { |
| 185 | i -= r; |
| 186 | if (i > 0) |
| 187 | memmove(c, c+r, i); |
| 188 | } |
| 189 | } |
| 190 | } |
| 191 | } |
| 192 | |
| 193 | static struct tty_driver *hvc_console_device(struct console *c, int *index) |
| 194 | { |
Milton Miller | 7805b1b | 2005-07-07 17:56:23 -0700 | [diff] [blame] | 195 | if (vtermnos[c->index] == -1) |
| 196 | return NULL; |
| 197 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 198 | *index = c->index; |
| 199 | return hvc_driver; |
| 200 | } |
| 201 | |
| 202 | static int __init hvc_console_setup(struct console *co, char *options) |
| 203 | { |
Milton Miller | 7805b1b | 2005-07-07 17:56:23 -0700 | [diff] [blame] | 204 | if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES) |
| 205 | return -ENODEV; |
| 206 | |
| 207 | if (vtermnos[co->index] == -1) |
| 208 | return -ENODEV; |
| 209 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 210 | return 0; |
| 211 | } |
| 212 | |
| 213 | struct console hvc_con_driver = { |
| 214 | .name = "hvc", |
| 215 | .write = hvc_console_print, |
| 216 | .device = hvc_console_device, |
| 217 | .setup = hvc_console_setup, |
| 218 | .flags = CON_PRINTBUFFER, |
| 219 | .index = -1, |
| 220 | }; |
| 221 | |
Milton Miller | d5ee257 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 222 | /* |
| 223 | * Early console initialization. Preceeds driver initialization. |
| 224 | * |
| 225 | * (1) we are first, and the user specified another driver |
| 226 | * -- index will remain -1 |
| 227 | * (2) we are first and the user specified no driver |
| 228 | * -- index will be set to 0, then we will fail setup. |
| 229 | * (3) we are first and the user specified our driver |
| 230 | * -- index will be set to user specified driver, and we will fail |
| 231 | * (4) we are after driver, and this initcall will register us |
| 232 | * -- if the user didn't specify a driver then the console will match |
| 233 | * |
| 234 | * Note that for cases 2 and 3, we will match later when the io driver |
| 235 | * calls hvc_instantiate() and call register again. |
| 236 | */ |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 237 | static int __init hvc_console_init(void) |
| 238 | { |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 239 | register_console(&hvc_con_driver); |
| 240 | return 0; |
| 241 | } |
| 242 | console_initcall(hvc_console_init); |
| 243 | |
| 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 | |
Milton Miller | 7805b1b | 2005-07-07 17:56:23 -0700 | [diff] [blame] | 260 | /* make sure no no tty has been registerd in this index */ |
| 261 | hp = hvc_get_by_index(index); |
| 262 | if (hp) { |
| 263 | kobject_put(&hp->kobj); |
| 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 | |
| 270 | /* reserve all indices upto and including this index */ |
| 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 | } |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 283 | EXPORT_SYMBOL(hvc_instantiate); |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 284 | |
| 285 | /* Wake the sleeping khvcd */ |
| 286 | static void hvc_kick(void) |
| 287 | { |
| 288 | hvc_kicked = 1; |
| 289 | wake_up_process(hvc_task); |
| 290 | } |
| 291 | |
Milton Miller | 8b67f8c | 2005-07-07 17:56:18 -0700 | [diff] [blame] | 292 | static int hvc_poll(struct hvc_struct *hp); |
| 293 | |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 294 | /* |
| 295 | * NOTE: This API isn't used if the console adapter doesn't support interrupts. |
| 296 | * In this case the console is poll driven. |
| 297 | */ |
| 298 | static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance, struct pt_regs *regs) |
| 299 | { |
Milton Miller | 8b67f8c | 2005-07-07 17:56:18 -0700 | [diff] [blame] | 300 | /* if hvc_poll request a repoll, then kick the hvcd thread */ |
| 301 | if (hvc_poll(dev_instance)) |
| 302 | hvc_kick(); |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 303 | return IRQ_HANDLED; |
| 304 | } |
| 305 | |
| 306 | static void hvc_unthrottle(struct tty_struct *tty) |
| 307 | { |
| 308 | hvc_kick(); |
| 309 | } |
| 310 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | /* |
| 312 | * The TTY interface won't be used until after the vio layer has exposed the vty |
| 313 | * adapter to the kernel. |
| 314 | */ |
| 315 | static int hvc_open(struct tty_struct *tty, struct file * filp) |
| 316 | { |
| 317 | struct hvc_struct *hp; |
| 318 | unsigned long flags; |
| 319 | int irq = NO_IRQ; |
| 320 | int rc = 0; |
| 321 | struct kobject *kobjp; |
| 322 | |
| 323 | /* Auto increments kobject reference if found. */ |
| 324 | if (!(hp = hvc_get_by_index(tty->index))) { |
| 325 | printk(KERN_WARNING "hvc_console: tty open failed, no vty associated with tty.\n"); |
| 326 | return -ENODEV; |
| 327 | } |
| 328 | |
| 329 | spin_lock_irqsave(&hp->lock, flags); |
| 330 | /* Check and then increment for fast path open. */ |
| 331 | if (hp->count++ > 0) { |
| 332 | spin_unlock_irqrestore(&hp->lock, flags); |
| 333 | hvc_kick(); |
| 334 | return 0; |
| 335 | } /* else count == 0 */ |
| 336 | |
| 337 | tty->driver_data = hp; |
| 338 | hp->tty = tty; |
| 339 | /* Save for request_irq outside of spin_lock. */ |
| 340 | irq = hp->irq; |
| 341 | if (irq != NO_IRQ) |
| 342 | hp->irq_requested = 1; |
| 343 | |
| 344 | kobjp = &hp->kobj; |
| 345 | |
| 346 | spin_unlock_irqrestore(&hp->lock, flags); |
| 347 | /* check error, fallback to non-irq */ |
| 348 | if (irq != NO_IRQ) |
| 349 | rc = request_irq(irq, hvc_handle_interrupt, SA_INTERRUPT, "hvc_console", hp); |
| 350 | |
| 351 | /* |
| 352 | * If the request_irq() fails and we return an error. The tty layer |
| 353 | * will call hvc_close() after a failed open but we don't want to clean |
| 354 | * up there so we'll clean up here and clear out the previously set |
| 355 | * tty fields and return the kobject reference. |
| 356 | */ |
| 357 | if (rc) { |
| 358 | spin_lock_irqsave(&hp->lock, flags); |
| 359 | hp->tty = NULL; |
| 360 | hp->irq_requested = 0; |
| 361 | spin_unlock_irqrestore(&hp->lock, flags); |
| 362 | tty->driver_data = NULL; |
| 363 | kobject_put(kobjp); |
| 364 | printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc); |
| 365 | } |
| 366 | /* Force wakeup of the polling thread */ |
| 367 | hvc_kick(); |
| 368 | |
| 369 | return rc; |
| 370 | } |
| 371 | |
| 372 | static void hvc_close(struct tty_struct *tty, struct file * filp) |
| 373 | { |
| 374 | struct hvc_struct *hp; |
| 375 | struct kobject *kobjp; |
| 376 | int irq = NO_IRQ; |
| 377 | unsigned long flags; |
| 378 | |
| 379 | if (tty_hung_up_p(filp)) |
| 380 | return; |
| 381 | |
| 382 | /* |
| 383 | * No driver_data means that this close was issued after a failed |
| 384 | * hvc_open by the tty layer's release_dev() function and we can just |
| 385 | * exit cleanly because the kobject reference wasn't made. |
| 386 | */ |
| 387 | if (!tty->driver_data) |
| 388 | return; |
| 389 | |
| 390 | hp = tty->driver_data; |
| 391 | spin_lock_irqsave(&hp->lock, flags); |
| 392 | |
| 393 | kobjp = &hp->kobj; |
| 394 | if (--hp->count == 0) { |
| 395 | if (hp->irq_requested) |
| 396 | irq = hp->irq; |
| 397 | hp->irq_requested = 0; |
| 398 | |
| 399 | /* We are done with the tty pointer now. */ |
| 400 | hp->tty = NULL; |
| 401 | spin_unlock_irqrestore(&hp->lock, flags); |
| 402 | |
| 403 | /* |
| 404 | * Chain calls chars_in_buffer() and returns immediately if |
| 405 | * there is no buffered data otherwise sleeps on a wait queue |
| 406 | * waking periodically to check chars_in_buffer(). |
| 407 | */ |
| 408 | tty_wait_until_sent(tty, HVC_CLOSE_WAIT); |
| 409 | |
| 410 | if (irq != NO_IRQ) |
| 411 | free_irq(irq, hp); |
| 412 | |
| 413 | } else { |
| 414 | if (hp->count < 0) |
| 415 | printk(KERN_ERR "hvc_close %X: oops, count is %d\n", |
| 416 | hp->vtermno, hp->count); |
| 417 | spin_unlock_irqrestore(&hp->lock, flags); |
| 418 | } |
| 419 | |
| 420 | kobject_put(kobjp); |
| 421 | } |
| 422 | |
| 423 | static void hvc_hangup(struct tty_struct *tty) |
| 424 | { |
| 425 | struct hvc_struct *hp = tty->driver_data; |
| 426 | unsigned long flags; |
| 427 | int irq = NO_IRQ; |
| 428 | int temp_open_count; |
| 429 | struct kobject *kobjp; |
| 430 | |
| 431 | if (!hp) |
| 432 | return; |
| 433 | |
| 434 | spin_lock_irqsave(&hp->lock, flags); |
| 435 | |
| 436 | /* |
| 437 | * The N_TTY line discipline has problems such that in a close vs |
| 438 | * open->hangup case this can be called after the final close so prevent |
| 439 | * that from happening for now. |
| 440 | */ |
| 441 | if (hp->count <= 0) { |
| 442 | spin_unlock_irqrestore(&hp->lock, flags); |
| 443 | return; |
| 444 | } |
| 445 | |
| 446 | kobjp = &hp->kobj; |
| 447 | temp_open_count = hp->count; |
| 448 | hp->count = 0; |
| 449 | hp->n_outbuf = 0; |
| 450 | hp->tty = NULL; |
| 451 | if (hp->irq_requested) |
| 452 | /* Saved for use outside of spin_lock. */ |
| 453 | irq = hp->irq; |
| 454 | hp->irq_requested = 0; |
| 455 | spin_unlock_irqrestore(&hp->lock, flags); |
| 456 | if (irq != NO_IRQ) |
| 457 | free_irq(irq, hp); |
| 458 | while(temp_open_count) { |
| 459 | --temp_open_count; |
| 460 | kobject_put(kobjp); |
| 461 | } |
| 462 | } |
| 463 | |
| 464 | /* |
| 465 | * Push buffered characters whether they were just recently buffered or waiting |
| 466 | * on a blocked hypervisor. Call this function with hp->lock held. |
| 467 | */ |
| 468 | static void hvc_push(struct hvc_struct *hp) |
| 469 | { |
| 470 | int n; |
| 471 | |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 472 | n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | if (n <= 0) { |
| 474 | if (n == 0) |
| 475 | return; |
| 476 | /* throw away output on error; this happens when |
| 477 | there is no session connected to the vterm. */ |
| 478 | hp->n_outbuf = 0; |
| 479 | } else |
| 480 | hp->n_outbuf -= n; |
| 481 | if (hp->n_outbuf > 0) |
| 482 | memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf); |
| 483 | else |
| 484 | hp->do_wakeup = 1; |
| 485 | } |
| 486 | |
| 487 | static inline int __hvc_write_kernel(struct hvc_struct *hp, |
| 488 | const unsigned char *buf, int count) |
| 489 | { |
| 490 | unsigned long flags; |
| 491 | int rsize, written = 0; |
| 492 | |
| 493 | spin_lock_irqsave(&hp->lock, flags); |
| 494 | |
| 495 | /* Push pending writes */ |
| 496 | if (hp->n_outbuf > 0) |
| 497 | hvc_push(hp); |
| 498 | |
| 499 | while (count > 0 && (rsize = N_OUTBUF - hp->n_outbuf) > 0) { |
| 500 | if (rsize > count) |
| 501 | rsize = count; |
| 502 | memcpy(hp->outbuf + hp->n_outbuf, buf, rsize); |
| 503 | count -= rsize; |
| 504 | buf += rsize; |
| 505 | hp->n_outbuf += rsize; |
| 506 | written += rsize; |
| 507 | hvc_push(hp); |
| 508 | } |
| 509 | spin_unlock_irqrestore(&hp->lock, flags); |
| 510 | |
| 511 | return written; |
| 512 | } |
| 513 | static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count) |
| 514 | { |
| 515 | struct hvc_struct *hp = tty->driver_data; |
| 516 | int written; |
| 517 | |
| 518 | /* This write was probably executed during a tty close. */ |
| 519 | if (!hp) |
| 520 | return -EPIPE; |
| 521 | |
| 522 | if (hp->count <= 0) |
| 523 | return -EIO; |
| 524 | |
| 525 | written = __hvc_write_kernel(hp, buf, count); |
| 526 | |
| 527 | /* |
| 528 | * Racy, but harmless, kick thread if there is still pending data. |
| 529 | * There really is nothing wrong with kicking the thread, even if there |
| 530 | * is no buffered data. |
| 531 | */ |
| 532 | if (hp->n_outbuf) |
| 533 | hvc_kick(); |
| 534 | |
| 535 | return written; |
| 536 | } |
| 537 | |
| 538 | /* |
| 539 | * This is actually a contract between the driver and the tty layer outlining |
| 540 | * how much write room the driver can guarentee will be sent OR BUFFERED. This |
| 541 | * driver MUST honor the return value. |
| 542 | */ |
| 543 | static int hvc_write_room(struct tty_struct *tty) |
| 544 | { |
| 545 | struct hvc_struct *hp = tty->driver_data; |
| 546 | |
| 547 | if (!hp) |
| 548 | return -1; |
| 549 | |
| 550 | return N_OUTBUF - hp->n_outbuf; |
| 551 | } |
| 552 | |
| 553 | static int hvc_chars_in_buffer(struct tty_struct *tty) |
| 554 | { |
| 555 | struct hvc_struct *hp = tty->driver_data; |
| 556 | |
| 557 | if (!hp) |
| 558 | return -1; |
| 559 | return hp->n_outbuf; |
| 560 | } |
| 561 | |
| 562 | #define HVC_POLL_READ 0x00000001 |
| 563 | #define HVC_POLL_WRITE 0x00000002 |
| 564 | #define HVC_POLL_QUICK 0x00000004 |
| 565 | |
| 566 | static int hvc_poll(struct hvc_struct *hp) |
| 567 | { |
| 568 | struct tty_struct *tty; |
| 569 | int i, n, poll_mask = 0; |
| 570 | char buf[N_INBUF] __ALIGNED__; |
| 571 | unsigned long flags; |
| 572 | int read_total = 0; |
| 573 | |
| 574 | spin_lock_irqsave(&hp->lock, flags); |
| 575 | |
| 576 | /* Push pending writes */ |
| 577 | if (hp->n_outbuf > 0) |
| 578 | hvc_push(hp); |
| 579 | /* Reschedule us if still some write pending */ |
| 580 | if (hp->n_outbuf > 0) |
| 581 | poll_mask |= HVC_POLL_WRITE; |
| 582 | |
| 583 | /* No tty attached, just skip */ |
| 584 | tty = hp->tty; |
| 585 | if (tty == NULL) |
| 586 | goto bail; |
| 587 | |
| 588 | /* Now check if we can get data (are we throttled ?) */ |
| 589 | if (test_bit(TTY_THROTTLED, &tty->flags)) |
| 590 | goto throttled; |
| 591 | |
| 592 | /* If we aren't interrupt driven and aren't throttled, we always |
| 593 | * request a reschedule |
| 594 | */ |
| 595 | if (hp->irq == NO_IRQ) |
| 596 | poll_mask |= HVC_POLL_READ; |
| 597 | |
| 598 | /* Read data if any */ |
| 599 | for (;;) { |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 600 | int count = tty_buffer_request_room(tty, N_INBUF); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | |
| 602 | /* If flip is full, just reschedule a later read */ |
| 603 | if (count == 0) { |
| 604 | poll_mask |= HVC_POLL_READ; |
| 605 | break; |
| 606 | } |
| 607 | |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 608 | n = hp->ops->get_chars(hp->vtermno, buf, count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 609 | if (n <= 0) { |
| 610 | /* Hangup the tty when disconnected from host */ |
| 611 | if (n == -EPIPE) { |
| 612 | spin_unlock_irqrestore(&hp->lock, flags); |
| 613 | tty_hangup(tty); |
| 614 | spin_lock_irqsave(&hp->lock, flags); |
| 615 | } |
| 616 | break; |
| 617 | } |
| 618 | for (i = 0; i < n; ++i) { |
| 619 | #ifdef CONFIG_MAGIC_SYSRQ |
Milton Miller | 2b9e0ba | 2005-07-07 17:56:19 -0700 | [diff] [blame] | 620 | if (hp->index == hvc_con_driver.index) { |
| 621 | /* Handle the SysRq Hack */ |
| 622 | /* XXX should support a sequence */ |
| 623 | if (buf[i] == '\x0f') { /* ^O */ |
| 624 | sysrq_pressed = 1; |
| 625 | continue; |
| 626 | } else if (sysrq_pressed) { |
| 627 | handle_sysrq(buf[i], NULL, tty); |
| 628 | sysrq_pressed = 0; |
| 629 | continue; |
| 630 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | } |
| 632 | #endif /* CONFIG_MAGIC_SYSRQ */ |
| 633 | tty_insert_flip_char(tty, buf[i], 0); |
| 634 | } |
| 635 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 636 | if (count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 637 | tty_schedule_flip(tty); |
| 638 | |
| 639 | /* |
| 640 | * Account for the total amount read in one loop, and if above |
Milton Miller | 8b67f8c | 2005-07-07 17:56:18 -0700 | [diff] [blame] | 641 | * 64 bytes, we do a quick schedule loop to let the tty grok |
| 642 | * the data and eventually throttle us. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 643 | */ |
| 644 | read_total += n; |
| 645 | if (read_total >= 64) { |
| 646 | poll_mask |= HVC_POLL_QUICK; |
| 647 | break; |
| 648 | } |
| 649 | } |
| 650 | throttled: |
| 651 | /* Wakeup write queue if necessary */ |
| 652 | if (hp->do_wakeup) { |
| 653 | hp->do_wakeup = 0; |
| 654 | tty_wakeup(tty); |
| 655 | } |
| 656 | bail: |
| 657 | spin_unlock_irqrestore(&hp->lock, flags); |
| 658 | |
| 659 | return poll_mask; |
| 660 | } |
| 661 | |
| 662 | #if defined(CONFIG_XMON) && defined(CONFIG_SMP) |
| 663 | extern cpumask_t cpus_in_xmon; |
| 664 | #else |
| 665 | static const cpumask_t cpus_in_xmon = CPU_MASK_NONE; |
| 666 | #endif |
| 667 | |
| 668 | /* |
| 669 | * This kthread is either polling or interrupt driven. This is determined by |
| 670 | * calling hvc_poll() who determines whether a console adapter support |
| 671 | * interrupts. |
| 672 | */ |
| 673 | int khvcd(void *unused) |
| 674 | { |
| 675 | int poll_mask; |
| 676 | struct hvc_struct *hp; |
| 677 | |
| 678 | __set_current_state(TASK_RUNNING); |
| 679 | do { |
| 680 | poll_mask = 0; |
| 681 | hvc_kicked = 0; |
| 682 | wmb(); |
| 683 | if (cpus_empty(cpus_in_xmon)) { |
| 684 | spin_lock(&hvc_structs_lock); |
| 685 | list_for_each_entry(hp, &hvc_structs, next) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 686 | poll_mask |= hvc_poll(hp); |
| 687 | } |
| 688 | spin_unlock(&hvc_structs_lock); |
| 689 | } else |
| 690 | poll_mask |= HVC_POLL_READ; |
| 691 | if (hvc_kicked) |
| 692 | continue; |
| 693 | if (poll_mask & HVC_POLL_QUICK) { |
| 694 | yield(); |
| 695 | continue; |
| 696 | } |
| 697 | set_current_state(TASK_INTERRUPTIBLE); |
| 698 | if (!hvc_kicked) { |
| 699 | if (poll_mask == 0) |
| 700 | schedule(); |
| 701 | else |
| 702 | msleep_interruptible(TIMEOUT); |
| 703 | } |
| 704 | __set_current_state(TASK_RUNNING); |
| 705 | } while (!kthread_should_stop()); |
| 706 | |
| 707 | return 0; |
| 708 | } |
| 709 | |
| 710 | static struct tty_operations hvc_ops = { |
| 711 | .open = hvc_open, |
| 712 | .close = hvc_close, |
| 713 | .write = hvc_write, |
| 714 | .hangup = hvc_hangup, |
| 715 | .unthrottle = hvc_unthrottle, |
| 716 | .write_room = hvc_write_room, |
| 717 | .chars_in_buffer = hvc_chars_in_buffer, |
| 718 | }; |
| 719 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | /* callback when the kboject ref count reaches zero. */ |
| 721 | static void destroy_hvc_struct(struct kobject *kobj) |
| 722 | { |
| 723 | struct hvc_struct *hp = container_of(kobj, struct hvc_struct, kobj); |
| 724 | unsigned long flags; |
| 725 | |
| 726 | spin_lock(&hvc_structs_lock); |
| 727 | |
| 728 | spin_lock_irqsave(&hp->lock, flags); |
| 729 | list_del(&(hp->next)); |
| 730 | spin_unlock_irqrestore(&hp->lock, flags); |
| 731 | |
| 732 | spin_unlock(&hvc_structs_lock); |
| 733 | |
| 734 | kfree(hp); |
| 735 | } |
| 736 | |
| 737 | static struct kobj_type hvc_kobj_type = { |
| 738 | .release = destroy_hvc_struct, |
| 739 | }; |
| 740 | |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 741 | struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int irq, |
| 742 | struct hv_ops *ops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | { |
| 744 | struct hvc_struct *hp; |
Milton Miller | 6f24808 | 2005-07-07 17:56:17 -0700 | [diff] [blame] | 745 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 746 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | hp = kmalloc(sizeof(*hp), GFP_KERNEL); |
| 748 | if (!hp) |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 749 | return ERR_PTR(-ENOMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 750 | |
| 751 | memset(hp, 0x00, sizeof(*hp)); |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 752 | |
| 753 | hp->vtermno = vtermno; |
| 754 | hp->irq = irq; |
Milton Miller | 030ffad | 2005-07-07 17:56:25 -0700 | [diff] [blame] | 755 | hp->ops = ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 756 | |
| 757 | kobject_init(&hp->kobj); |
| 758 | hp->kobj.ktype = &hvc_kobj_type; |
| 759 | |
| 760 | spin_lock_init(&hp->lock); |
| 761 | spin_lock(&hvc_structs_lock); |
Milton Miller | 6f24808 | 2005-07-07 17:56:17 -0700 | [diff] [blame] | 762 | |
| 763 | /* |
| 764 | * find index to use: |
| 765 | * see if this vterm id matches one registered for console. |
| 766 | */ |
| 767 | for (i=0; i < MAX_NR_HVC_CONSOLES; i++) |
| 768 | if (vtermnos[i] == hp->vtermno) |
| 769 | break; |
| 770 | |
| 771 | /* no matching slot, just use a counter */ |
| 772 | if (i >= MAX_NR_HVC_CONSOLES) |
| 773 | i = ++last_hvc; |
| 774 | |
| 775 | hp->index = i; |
| 776 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | list_add_tail(&(hp->next), &hvc_structs); |
| 778 | spin_unlock(&hvc_structs_lock); |
| 779 | |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 780 | return hp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 781 | } |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 782 | EXPORT_SYMBOL(hvc_alloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 783 | |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 784 | int __devexit hvc_remove(struct hvc_struct *hp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 785 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | unsigned long flags; |
| 787 | struct kobject *kobjp; |
| 788 | struct tty_struct *tty; |
| 789 | |
| 790 | spin_lock_irqsave(&hp->lock, flags); |
| 791 | tty = hp->tty; |
| 792 | kobjp = &hp->kobj; |
| 793 | |
| 794 | if (hp->index < MAX_NR_HVC_CONSOLES) |
| 795 | vtermnos[hp->index] = -1; |
| 796 | |
| 797 | /* Don't whack hp->irq because tty_hangup() will need to free the irq. */ |
| 798 | |
| 799 | spin_unlock_irqrestore(&hp->lock, flags); |
| 800 | |
| 801 | /* |
| 802 | * We 'put' the instance that was grabbed when the kobject instance |
| 803 | * was intialized using kobject_init(). Let the last holder of this |
| 804 | * kobject cause it to be removed, which will probably be the tty_hangup |
| 805 | * below. |
| 806 | */ |
| 807 | kobject_put(kobjp); |
| 808 | |
| 809 | /* |
| 810 | * This function call will auto chain call hvc_hangup. The tty should |
| 811 | * always be valid at this time unless a simultaneous tty close already |
| 812 | * cleaned up the hvc_struct. |
| 813 | */ |
| 814 | if (tty) |
| 815 | tty_hangup(tty); |
| 816 | return 0; |
| 817 | } |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 818 | EXPORT_SYMBOL(hvc_remove); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | |
| 820 | /* Driver initialization. Follow console initialization. This is where the TTY |
| 821 | * interfaces start to become available. */ |
| 822 | int __init hvc_init(void) |
| 823 | { |
Milton Miller | 5f6d9c0 | 2005-07-07 17:56:21 -0700 | [diff] [blame] | 824 | /* We need more than hvc_count adapters due to hotplug additions. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 825 | hvc_driver = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 826 | if (!hvc_driver) |
| 827 | return -ENOMEM; |
| 828 | |
| 829 | hvc_driver->owner = THIS_MODULE; |
| 830 | hvc_driver->devfs_name = "hvc/"; |
| 831 | hvc_driver->driver_name = "hvc"; |
| 832 | hvc_driver->name = "hvc"; |
| 833 | hvc_driver->major = HVC_MAJOR; |
| 834 | hvc_driver->minor_start = HVC_MINOR; |
| 835 | hvc_driver->type = TTY_DRIVER_TYPE_SYSTEM; |
| 836 | hvc_driver->init_termios = tty_std_termios; |
| 837 | hvc_driver->flags = TTY_DRIVER_REAL_RAW; |
| 838 | tty_set_operations(hvc_driver, &hvc_ops); |
| 839 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 840 | /* Always start the kthread because there can be hotplug vty adapters |
| 841 | * added later. */ |
| 842 | hvc_task = kthread_run(khvcd, NULL, "khvcd"); |
| 843 | if (IS_ERR(hvc_task)) { |
| 844 | panic("Couldn't create kthread for console.\n"); |
| 845 | put_tty_driver(hvc_driver); |
| 846 | return -EIO; |
| 847 | } |
| 848 | |
Anton Blanchard | ef4cbee | 2005-09-14 14:19:18 -0700 | [diff] [blame] | 849 | if (tty_register_driver(hvc_driver)) |
| 850 | panic("Couldn't register hvc console driver\n"); |
| 851 | |
Milton Miller | acad955 | 2005-07-07 17:56:24 -0700 | [diff] [blame] | 852 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | } |
Milton Miller | 837dcfa | 2005-07-07 17:56:16 -0700 | [diff] [blame] | 854 | module_init(hvc_init); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 855 | |
Milton Miller | 320da0d | 2005-07-07 17:56:20 -0700 | [diff] [blame] | 856 | /* This isn't particularily necessary due to this being a console driver |
| 857 | * but it is nice to be thorough. |
| 858 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 859 | static void __exit hvc_exit(void) |
| 860 | { |
| 861 | kthread_stop(hvc_task); |
| 862 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 863 | tty_unregister_driver(hvc_driver); |
| 864 | /* return tty_struct instances allocated in hvc_init(). */ |
| 865 | put_tty_driver(hvc_driver); |
Milton Miller | 320da0d | 2005-07-07 17:56:20 -0700 | [diff] [blame] | 866 | unregister_console(&hvc_con_driver); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 867 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 868 | module_exit(hvc_exit); |