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       xc_cnprobe;
  49 static cn_init_t        xc_cninit;
  50 static cn_term_t        xc_cnterm;
  51 static cn_getc_t        xc_cngetc;
  52 static cn_putc_t        xc_cnputc;
  53 static cn_grab_t        xc_cngrab;
  54 static cn_ungrab_t      xc_cnungrab;
  55
  56 #define XC_POLLTIME     (hz/10)
  57
  58 CONSOLE_DRIVER(xc);
  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 #ifdef KDB
  76 static int      xc_altbrk;
  77 #endif
  78
  79 #define CDEV_MAJOR 12
  80 #define XCUNIT(x)       (dev2unit(x))
  81 #define ISTTYOPEN(tp)   ((tp) && ((tp)->t_state & TS_ISOPEN))
  82 #define CN_LOCK_INIT(x, _name) \
  83         mtx_init(&x, _name, NULL, MTX_SPIN|MTX_RECURSE)
  84
  85 #define CN_LOCK(l)                                                                      \
  86                 do {                                                                                    \
  87                                 if (panicstr == NULL)                                   \
  88                         mtx_lock_spin(&(l));                    \
  89                 } while (0)
  90 #define CN_UNLOCK(l)                                                            \
  91                 do {                                                                                    \
  92                                 if (panicstr == NULL)                                   \
  93                         mtx_unlock_spin(&(l));                  \
  94                 } while (0)
  95 #define CN_LOCK_ASSERT(x)    mtx_assert(&x, MA_OWNED)
  96 #define CN_LOCK_DESTROY(x)   mtx_destroy(&x)
  97
  98
  99 static struct tty *xccons;
 100
 101 static tsw_open_t       xcopen;
 102 static tsw_close_t      xcclose;
 103
 104 static struct ttydevsw xc_ttydevsw = {
 105         .tsw_flags      = TF_NOPREFIX,
 106         .tsw_open       = xcopen,
 107         .tsw_close      = xcclose,
 108         .tsw_outwakeup  = xcoutwakeup,
 109 };
 110
 111 static void
 112 xc_cnprobe(struct consdev *cp)
 113 {
 114         cp->cn_pri = CN_REMOTE;
 115         sprintf(cp->cn_name, "%s0", driver_name);
 116 }
 117
 118
 119 static void
 120 xc_cninit(struct consdev *cp)
 121 {
 122         CN_LOCK_INIT(cn_mtx,"XCONS LOCK");
 123
 124 }
 125
 126 static void
 127 xc_cnterm(struct consdev *cp)
 128 {
 129 }
 130
 131 static void
 132 xc_cngrab(struct consdev *cp)
 133 {
 134 }
 135
 136 static void
 137 xc_cnungrab(struct consdev *cp)
 138 {
 139 }
 140
 141 static int
 142 xc_cngetc(struct consdev *dev)
 143 {
 144         int ret;
 145
 146         if (xencons_has_input())
 147                 xencons_handle_input(NULL);
 148
 149         CN_LOCK(cn_mtx);
 150         if ((rp - rc) && !xc_mute) {
 151                 /* we need to return only one char */
 152                 ret = (int)rbuf[RBUF_MASK(rc)];
 153                 rc++;
 154         } else
 155                 ret = -1;
 156         CN_UNLOCK(cn_mtx);
 157         return(ret);
 158 }
 159
 160 static void
 161 xc_cnputc_domu(struct consdev *dev, int c)
 162 {
 163         xcons_putc(c);
 164 }
 165
 166 static void
 167 xc_cnputc_dom0(struct consdev *dev, int c)
 168 {
 169         HYPERVISOR_console_io(CONSOLEIO_write, 1, (char *)&c);
 170 }
 171
 172 static void
 173 xc_cnputc(struct consdev *dev, int c)
 174 {
 175
 176         if (xen_start_info->flags & SIF_INITDOMAIN)
 177                 xc_cnputc_dom0(dev, c);
 178         else
 179                 xc_cnputc_domu(dev, c);
 180 }
 181
 182 extern int db_active;
 183 static boolean_t
 184 xcons_putc(int c)
 185 {
 186         int force_flush = xc_mute ||
 187 #ifdef DDB
 188                 db_active ||
 189 #endif
 190                 panicstr;       /* we're not gonna recover, so force
 191                                  * flush
 192                                  */
 193
 194         if ((wp-wc) < (WBUF_SIZE-1)) {
 195                 if ((wbuf[WBUF_MASK(wp++)] = c) == '\n') {
 196                         wbuf[WBUF_MASK(wp++)] = '\r';
 197 #ifdef notyet
 198                         if (force_flush)
 199                                 xcons_force_flush();
 200 #endif
 201                 }
 202         } else if (force_flush) {
 203 #ifdef notyet
 204                 xcons_force_flush();
 205 #endif
 206         }
 207         if (cnsl_evt_reg)
 208                 __xencons_tx_flush();
 209
 210         /* inform start path that we're pretty full */
 211         return ((wp - wc) >= WBUF_SIZE - 100) ? TRUE : FALSE;
 212 }
 213
 214 static void
 215 xc_identify(driver_t *driver, device_t parent)
 216 {
 217         device_t child;
 218         child = BUS_ADD_CHILD(parent, 0, driver_name, 0);
 219         device_set_driver(child, driver);
 220         device_set_desc(child, "Xen Console");
 221 }
 222
 223 static int
 224 xc_probe(device_t dev)
 225 {
 226
 227         return (0);
 228 }
 229
 230 static int
 231 xc_attach(device_t dev)
 232 {
 233         int error;
 234
 235         xccons = tty_alloc(&xc_ttydevsw, NULL);
 236         tty_makedev(xccons, NULL, "xc%r", 0);
 237
 238         callout_init(&xc_callout, 0);
 239
 240         xencons_ring_init();
 241
 242         cnsl_evt_reg = 1;
 243         callout_reset(&xc_callout, XC_POLLTIME, xc_timeout, xccons);
 244
 245         if (xen_start_info->flags & SIF_INITDOMAIN) {
 246                         error = bind_virq_to_irqhandler(
 247                                  VIRQ_CONSOLE,
 248                                  0,
 249                                  "console",
 250                                  NULL,
 251                                  xencons_priv_interrupt, NULL,
 252                                  INTR_TYPE_TTY, NULL);
 253
 254                                 KASSERT(error >= 0, ("can't register console interrupt"));
 255         }
 256
 257         /* register handler to flush console on shutdown */
 258         if ((EVENTHANDLER_REGISTER(shutdown_post_sync, xc_shutdown,
 259                                    NULL, SHUTDOWN_PRI_DEFAULT)) == NULL)
 260                 printf("xencons: shutdown event registration failed!\n");
 261
 262         return (0);
 263 }
 264
 265 /*
 266  * return 0 for all console input, force flush all output.
 267  */
 268 static void
 269 xc_shutdown(void *arg, int howto)
 270 {
 271         xc_mute = 1;
 272         xcons_force_flush();
 273 }
 274
 275 void
 276 xencons_rx(char *buf, unsigned len)
 277 {
 278         int           i;
 279         struct tty *tp = xccons;
 280
 281         if (xen_console_up
 282 #ifdef DDB
 283             && !kdb_active
 284 #endif
 285                 ) {
 286                 tty_lock(tp);
 287                 for (i = 0; i < len; i++) {
 288 #ifdef KDB
 289                         kdb_alt_break(buf[i], &xc_altbrk);
 290 #endif
 291                         ttydisc_rint(tp, buf[i], 0);
 292                 }
 293                 ttydisc_rint_done(tp);
 294                 tty_unlock(tp);
 295         } else {
 296                 CN_LOCK(cn_mtx);
 297                 for (i = 0; i < len; i++)
 298                         rbuf[RBUF_MASK(rp++)] = buf[i];
 299                 CN_UNLOCK(cn_mtx);
 300         }
 301 }
 302
 303 static void
 304 __xencons_tx_flush(void)
 305 {
 306         int        sz;
 307
 308         CN_LOCK(cn_mtx);
 309         while (wc != wp) {
 310                 int sent;
 311                 sz = wp - wc;
 312                 if (sz > (WBUF_SIZE - WBUF_MASK(wc)))
 313                         sz = WBUF_SIZE - WBUF_MASK(wc);
 314                 if (xen_start_info->flags & SIF_INITDOMAIN) {
 315                         HYPERVISOR_console_io(CONSOLEIO_write, sz, &wbuf[WBUF_MASK(wc)]);
 316                         wc += sz;
 317                 } else {
 318                         sent = xencons_ring_send(&wbuf[WBUF_MASK(wc)], sz);
 319                         if (sent == 0)
 320                                 break;
 321                         wc += sent;
 322                 }
 323         }
 324         CN_UNLOCK(cn_mtx);
 325 }
 326
 327 void
 328 xencons_tx(void)
 329 {
 330         __xencons_tx_flush();
 331 }
 332
 333 static void
 334 xencons_priv_interrupt(void *arg)
 335 {
 336
 337         static char rbuf[16];
 338         int         l;
 339
 340         while ((l = HYPERVISOR_console_io(CONSOLEIO_read, 16, rbuf)) > 0)
 341                 xencons_rx(rbuf, l);
 342
 343         xencons_tx();
 344 }
 345
 346 static int
 347 xcopen(struct tty *tp)
 348 {
 349
 350         xen_console_up = 1;
 351         return (0);
 352 }
 353
 354 static void
 355 xcclose(struct tty *tp)
 356 {
 357
 358         xen_console_up = 0;
 359 }
 360
 361 static inline int
 362 __xencons_put_char(int ch)
 363 {
 364         char _ch = (char)ch;
 365         if ((wp - wc) == WBUF_SIZE)
 366                 return 0;
 367         wbuf[WBUF_MASK(wp++)] = _ch;
 368         return 1;
 369 }
 370
 371
 372 static void
 373 xcoutwakeup(struct tty *tp)
 374 {
 375         boolean_t cons_full = FALSE;
 376         char c;
 377
 378         while (ttydisc_getc(tp, &c, 1) == 1 && !cons_full)
 379                 cons_full = xcons_putc(c);
 380
 381         if (cons_full) {
 382                 /* let the timeout kick us in a bit */
 383                 xc_start_needed = TRUE;
 384         }
 385
 386 }
 387
 388 static void
 389 xc_timeout(void *v)
 390 {
 391         struct  tty *tp;
 392         int     c;
 393
 394         tp = (struct tty *)v;
 395
 396         tty_lock(tp);
 397         while ((c = xc_cngetc(NULL)) != -1)
 398                 ttydisc_rint(tp, c, 0);
 399
 400         if (xc_start_needed) {
 401                 xc_start_needed = FALSE;
 402                 xcoutwakeup(tp);
 403         }
 404         tty_unlock(tp);
 405
 406         callout_reset(&xc_callout, XC_POLLTIME, xc_timeout, tp);
 407 }
 408
 409 static device_method_t xc_methods[] = {
 410         DEVMETHOD(device_identify, xc_identify),
 411         DEVMETHOD(device_probe, xc_probe),
 412         DEVMETHOD(device_attach, xc_attach),
 413         {0, 0}
 414 };
 415
 416 static driver_t xc_driver = {
 417         driver_name,
 418         xc_methods,
 419         0,
 420 };
 421
 422 /*** Forcibly flush console data before dying. ***/
 423 void
 424 xcons_force_flush(void)
 425 {
 426         int        sz;
 427
 428         if (xen_start_info->flags & SIF_INITDOMAIN)
 429                 return;
 430
 431         /* Spin until console data is flushed through to the domain controller. */
 432         while (wc != wp) {
 433                 int sent = 0;
 434                 if ((sz = wp - wc) == 0)
 435                         continue;
 436
 437                 sent = xencons_ring_send(&wbuf[WBUF_MASK(wc)], sz);
 438                 if (sent > 0)
 439                         wc += sent;
 440         }
 441 }
 442
 443 DRIVER_MODULE(xc, nexus, xc_driver, xc_devclass, 0, 0);