sys/dev/xen/console/console.c

   1 #include <sys/cdefs.h>
   2 __FBSDID("$FreeBSD$");
   3
   4 #include <sys/param.h>
   5 #include <sys/module.h>
   6 #include <sys/systm.h>
   7 #include <sys/consio.h>
   8 #include <sys/priv.h>
   9 #include <sys/proc.h>
  10 #include <sys/uio.h>
  11 #include <sys/tty.h>
  12 #include <sys/systm.h>
  13 #include <sys/taskqueue.h>
  14 #include <sys/conf.h>
  15 #include <sys/kernel.h>
  16 #include <sys/bus.h>
  17 #include <machine/stdarg.h>
  18 #include <machine/xen/xen-os.h>
  19 #include <xen/hypervisor.h>
  20 #include <xen/xen_intr.h>
  21 #include <sys/cons.h>
  22 #include <sys/kdb.h>
  23 #include <sys/proc.h>
  24
  25 #include <dev/xen/console/xencons_ring.h>
  26 #include <xen/interface/io/console.h>
  27
  28
  29 #include "opt_ddb.h"
  30 #ifdef DDB
  31 #include <ddb/ddb.h>
  32 #endif
  33
  34 static char driver_name[] = "xc";
  35 devclass_t xc_devclass; /* do not make static */
  36 static void     xcoutwakeup(struct tty *);
  37 static void     xc_timeout(void *);
  38 static void __xencons_tx_flush(void);
  39 static boolean_t xcons_putc(int c);
  40
  41 /* switch console so that shutdown can occur gracefully */
  42 static void xc_shutdown(void *arg, int howto);
  43 static int xc_mute;
  44
  45 static void xcons_force_flush(void);
  46 static void xencons_priv_interrupt(void *);
  47
  48 static cn_probe_t       xccnprobe;
  49 static cn_init_t        xccninit;
  50 static cn_getc_t        xccngetc;
  51 static cn_putc_t        xccnputc;
  52 static cn_putc_t        xccnputc_dom0;
  53 static cn_checkc_t      xccncheckc;
  54
  55 #define XC_POLLTIME     (hz/10)
  56
  57 CONS_DRIVER(xc, xccnprobe, xccninit, NULL, xccngetc,
  58             xccncheckc, xccnputc, NULL);
  59
  60 static int xen_console_up;
  61 static boolean_t xc_start_needed;
  62 static struct callout xc_callout;
  63 struct mtx              cn_mtx;
  64
  65 #define RBUF_SIZE     1024
  66 #define RBUF_MASK(_i) ((_i)&(RBUF_SIZE-1))
  67 #define WBUF_SIZE     4096
  68 #define WBUF_MASK(_i) ((_i)&(WBUF_SIZE-1))
  69 static char wbuf[WBUF_SIZE];
  70 static char rbuf[RBUF_SIZE];
  71 static int rc, rp;
  72 static unsigned int cnsl_evt_reg;
  73 static unsigned int wc, wp; /* write_cons, write_prod */
  74
  75 #define CDEV_MAJOR 12
  76 #define XCUNIT(x)       (dev2unit(x))
  77 #define ISTTYOPEN(tp)   ((tp) && ((tp)->t_state & TS_ISOPEN))
  78 #define CN_LOCK_INIT(x, _name) \
  79         mtx_init(&x, _name, NULL, MTX_SPIN|MTX_RECURSE)
  80
  81 #define CN_LOCK(l)                                                                      \
  82                 do {                                                                                    \
  83                                 if (panicstr == NULL)                                   \
  84                         mtx_lock_spin(&(l));                    \
  85                 } while (0)
  86 #define CN_UNLOCK(l)                                                            \
  87                 do {                                                                                    \
  88                                 if (panicstr == NULL)                                   \
  89                         mtx_unlock_spin(&(l));                  \
  90                 } while (0)
  91 #define CN_LOCK_ASSERT(x)    mtx_assert(&x, MA_OWNED)
  92 #define CN_LOCK_DESTROY(x)   mtx_destroy(&x)
  93
  94
  95 static struct tty *xccons;
  96
  97 static tsw_open_t       xcopen;
  98 static tsw_close_t      xcclose;
  99
 100 static struct ttydevsw xc_ttydevsw = {
 101         .tsw_flags      = TF_NOPREFIX,
 102         .tsw_open       = xcopen,
 103         .tsw_close      = xcclose,
 104         .tsw_outwakeup  = xcoutwakeup,
 105 };
 106
 107 static void
 108 xccnprobe(struct consdev *cp)
 109 {
 110         cp->cn_pri = CN_REMOTE;
 111         sprintf(cp->cn_name, "%s0", driver_name);
 112 }
 113
 114
 115 static void
 116 xccninit(struct consdev *cp)
 117 {
 118         CN_LOCK_INIT(cn_mtx,"XCONS LOCK");
 119
 120 }
 121 int
 122 xccngetc(struct consdev *dev)
 123 {
 124         int c;
 125         if (xc_mute)
 126                 return 0;
 127         do {
 128                 if ((c = xccncheckc(dev)) == -1) {
 129 #ifdef KDB
 130                         if (!kdb_active)
 131 #endif
 132                                 /*
 133                                  * Polling without sleeping in Xen
 134                                  * doesn't work well.  Sleeping gives
 135                                  * other things like clock a chance to
 136                                  * run
 137                                  */
 138                                 tsleep(&cn_mtx, PWAIT | PCATCH,
 139                                     "console sleep", XC_POLLTIME);
 140                 }
 141         } while(c == -1);
 142         return c;
 143 }
 144
 145 int
 146 xccncheckc(struct consdev *dev)
 147 {
 148         int ret = (xc_mute ? 0 : -1);
 149
 150         if (xencons_has_input())
 151                 xencons_handle_input(NULL);
 152
 153         CN_LOCK(cn_mtx);
 154         if ((rp - rc)) {
 155                 /* we need to return only one char */
 156                 ret = (int)rbuf[RBUF_MASK(rc)];
 157                 rc++;
 158         }
 159         CN_UNLOCK(cn_mtx);
 160         return(ret);
 161 }
 162
 163 static void
 164 xccnputc(struct consdev *dev, int c)
 165 {
 166         xcons_putc(c);
 167 }
 168
 169 static void
 170 xccnputc_dom0(struct consdev *dev, int c)
 171 {
 172         HYPERVISOR_console_io(CONSOLEIO_write, 1, (char *)&c);
 173 }
 174
 175 extern int db_active;
 176 static boolean_t
 177 xcons_putc(int c)
 178 {
 179         int force_flush = xc_mute ||
 180 #ifdef DDB
 181                 db_active ||
 182 #endif
 183                 panicstr;       /* we're not gonna recover, so force
 184                                  * flush
 185                                  */
 186
 187         if ((wp-wc) < (WBUF_SIZE-1)) {
 188                 if ((wbuf[WBUF_MASK(wp++)] = c) == '\n') {
 189                         wbuf[WBUF_MASK(wp++)] = '\r';
 190 #ifdef notyet
 191                         if (force_flush)
 192                                 xcons_force_flush();
 193 #endif
 194                 }
 195         } else if (force_flush) {
 196 #ifdef notyet
 197                 xcons_force_flush();
 198 #endif
 199         }
 200         if (cnsl_evt_reg)
 201                 __xencons_tx_flush();
 202
 203         /* inform start path that we're pretty full */
 204         return ((wp - wc) >= WBUF_SIZE - 100) ? TRUE : FALSE;
 205 }
 206
 207 static void
 208 xc_identify(driver_t *driver, device_t parent)
 209 {
 210         device_t child;
 211         child = BUS_ADD_CHILD(parent, 0, driver_name, 0);
 212         device_set_driver(child, driver);
 213         device_set_desc(child, "Xen Console");
 214 }
 215
 216 static int
 217 xc_probe(device_t dev)
 218 {
 219
 220         return (0);
 221 }
 222
 223 static int
 224 xc_attach(device_t dev)
 225 {
 226         int error;
 227
 228         if (xen_start_info->flags & SIF_INITDOMAIN) {
 229                 xc_consdev.cn_putc = xccnputc_dom0;
 230         }
 231
 232         xccons = tty_alloc(&xc_ttydevsw, NULL);
 233         tty_makedev(xccons, NULL, "xc%r", 0);
 234
 235         callout_init(&xc_callout, 0);
 236
 237         xencons_ring_init();
 238
 239         cnsl_evt_reg = 1;
 240         callout_reset(&xc_callout, XC_POLLTIME, xc_timeout, xccons);
 241
 242         if (xen_start_info->flags & SIF_INITDOMAIN) {
 243                         error = bind_virq_to_irqhandler(
 244                                  VIRQ_CONSOLE,
 245                                  0,
 246                                  "console",
 247                                  NULL,
 248                                  xencons_priv_interrupt, NULL,
 249                                  INTR_TYPE_TTY, NULL);
 250
 251                                 KASSERT(error >= 0, ("can't register console interrupt"));
 252         }
 253
 254         /* register handler to flush console on shutdown */
 255         if ((EVENTHANDLER_REGISTER(shutdown_post_sync, xc_shutdown,
 256                                    NULL, SHUTDOWN_PRI_DEFAULT)) == NULL)
 257                 printf("xencons: shutdown event registration failed!\n");
 258
 259         return (0);
 260 }
 261
 262 /*
 263  * return 0 for all console input, force flush all output.
 264  */
 265 static void
 266 xc_shutdown(void *arg, int howto)
 267 {
 268         xc_mute = 1;
 269         xcons_force_flush();
 270 }
 271
 272 void
 273 xencons_rx(char *buf, unsigned len)
 274 {
 275         int           i;
 276         struct tty *tp = xccons;
 277
 278         if (xen_console_up
 279 #ifdef DDB
 280             && !kdb_active
 281 #endif
 282                 ) {
 283                 tty_lock(tp);
 284                 for (i = 0; i < len; i++)
 285                         ttydisc_rint(tp, buf[i], 0);
 286                 ttydisc_rint_done(tp);
 287                 tty_unlock(tp);
 288         } else {
 289                 CN_LOCK(cn_mtx);
 290                 for (i = 0; i < len; i++)
 291                         rbuf[RBUF_MASK(rp++)] = buf[i];
 292                 CN_UNLOCK(cn_mtx);
 293         }
 294 }
 295
 296 static void
 297 __xencons_tx_flush(void)
 298 {
 299         int        sz;
 300
 301         CN_LOCK(cn_mtx);
 302         while (wc != wp) {
 303                 int sent;
 304                 sz = wp - wc;
 305                 if (sz > (WBUF_SIZE - WBUF_MASK(wc)))
 306                         sz = WBUF_SIZE - WBUF_MASK(wc);
 307                 if (xen_start_info->flags & SIF_INITDOMAIN) {
 308                         HYPERVISOR_console_io(CONSOLEIO_write, sz, &wbuf[WBUF_MASK(wc)]);
 309                         wc += sz;
 310                 } else {
 311                         sent = xencons_ring_send(&wbuf[WBUF_MASK(wc)], sz);
 312                         if (sent == 0)
 313                                 break;
 314                         wc += sent;
 315                 }
 316         }
 317         CN_UNLOCK(cn_mtx);
 318 }
 319
 320 void
 321 xencons_tx(void)
 322 {
 323         __xencons_tx_flush();
 324 }
 325
 326 static void
 327 xencons_priv_interrupt(void *arg)
 328 {
 329
 330         static char rbuf[16];
 331         int         l;
 332
 333         while ((l = HYPERVISOR_console_io(CONSOLEIO_read, 16, rbuf)) > 0)
 334                 xencons_rx(rbuf, l);
 335
 336         xencons_tx();
 337 }
 338
 339 static int
 340 xcopen(struct tty *tp)
 341 {
 342
 343         xen_console_up = 1;
 344         return (0);
 345 }
 346
 347 static void
 348 xcclose(struct tty *tp)
 349 {
 350
 351         xen_console_up = 0;
 352 }
 353
 354 static inline int
 355 __xencons_put_char(int ch)
 356 {
 357         char _ch = (char)ch;
 358         if ((wp - wc) == WBUF_SIZE)
 359                 return 0;
 360         wbuf[WBUF_MASK(wp++)] = _ch;
 361         return 1;
 362 }
 363
 364
 365 static void
 366 xcoutwakeup(struct tty *tp)
 367 {
 368         boolean_t cons_full = FALSE;
 369         char c;
 370
 371         while (ttydisc_getc(tp, &c, 1) == 1 && !cons_full)
 372                 cons_full = xcons_putc(c);
 373
 374         if (cons_full) {
 375                 /* let the timeout kick us in a bit */
 376                 xc_start_needed = TRUE;
 377         }
 378
 379 }
 380
 381 static void
 382 xc_timeout(void *v)
 383 {
 384         struct  tty *tp;
 385         int     c;
 386
 387         tp = (struct tty *)v;
 388
 389         tty_lock(tp);
 390         while ((c = xccncheckc(NULL)) != -1)
 391                 ttydisc_rint(tp, c, 0);
 392
 393         if (xc_start_needed) {
 394                 xc_start_needed = FALSE;
 395                 xcoutwakeup(tp);
 396         }
 397         tty_unlock(tp);
 398
 399         callout_reset(&xc_callout, XC_POLLTIME, xc_timeout, tp);
 400 }
 401
 402 static device_method_t xc_methods[] = {
 403         DEVMETHOD(device_identify, xc_identify),
 404         DEVMETHOD(device_probe, xc_probe),
 405         DEVMETHOD(device_attach, xc_attach),
 406         {0, 0}
 407 };
 408
 409 static driver_t xc_driver = {
 410         driver_name,
 411         xc_methods,
 412         0,
 413 };
 414
 415 /*** Forcibly flush console data before dying. ***/
 416 void
 417 xcons_force_flush(void)
 418 {
 419         int        sz;
 420
 421         if (xen_start_info->flags & SIF_INITDOMAIN)
 422                 return;
 423
 424         /* Spin until console data is flushed through to the domain controller. */
 425         while (wc != wp) {
 426                 int sent = 0;
 427                 if ((sz = wp - wc) == 0)
 428                         continue;
 429
 430                 sent = xencons_ring_send(&wbuf[WBUF_MASK(wc)], sz);
 431                 if (sent > 0)
 432                         wc += sent;
 433         }
 434 }
 435
 436 DRIVER_MODULE(xc, nexus, xc_driver, xc_devclass, 0, 0);