osfmk/ppc/console_feed.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_FREE_COPYRIGHT@
  24  *
  25  */
  26
  27 /* Intercept mach console output and supply it to a user application */
  28
  29 #include <mach_kdb.h>
  30
  31 #include <types.h>
  32 #include <device/buf.h>
  33 #include <device/conf.h>
  34 #include <device/errno.h>
  35 #include <device/misc_protos.h>
  36 #include <device/ds_routines.h>
  37 #include <device/cirbuf.h>
  38 #include <ppc/console_feed_entries.h>
  39 #include <ppc/serial_io.h>
  40
  41 #if     MACH_KDB
  42 #include <ppc/db_machdep.h>
  43 #endif  /* MACH_KDB */
  44
  45 static struct cirbuf cons_feed_cb;
  46 static int cons_feed_count = 0;
  47 io_req_t   cons_feed_queued = 0;
  48
  49 /* console feed lock should be taken at splhigh */
  50 decl_simple_lock_data(,cons_feed_lock)
  51
  52 boolean_t cons_feed_read_done(io_req_t ior);
  53
  54 io_return_t
  55 console_feed_open(
  56         dev_t           dev,
  57         dev_mode_t      flag,
  58         io_req_t        ior)
  59 {
  60         spl_t   s;
  61
  62         simple_lock_init(&cons_feed_lock, 0);
  63 #if     MACH_KDB
  64         if (console_is_serial()) {
  65                 return D_DEVICE_DOWN;
  66         }
  67 #endif  /* MACH_KDB */
  68         cb_alloc(&cons_feed_cb, CONSOLE_FEED_BUFSIZE);
  69         s = splhigh();
  70         simple_lock(&cons_feed_lock);
  71         cons_feed_count++;
  72         simple_unlock(&cons_feed_lock);
  73         splx(s);
  74         return D_SUCCESS;
  75 }
  76
  77 void
  78 console_feed_close(
  79         dev_t           dev)
  80 {
  81         spl_t   s;
  82
  83         s = splhigh();
  84         simple_lock(&cons_feed_lock);
  85         cons_feed_count--;
  86         simple_unlock(&cons_feed_lock);
  87         splx(s);
  88
  89         console_feed_cancel_and_flush();
  90         cb_free(&cons_feed_cb);
  91
  92         return;
  93 }
  94
  95 /* A routine that can be called from a panic or other problem
  96  * situation. It switches off the console feed and dumps any
  97  * remaining buffered information to the original console
  98  * (usually the screen). It doesn't free up the buffer, since
  99  * it tries to be as minimal as possible
 100  */
 101
 102 void console_feed_cancel_and_flush(void)
 103 {
 104         int     c;
 105         spl_t   s;
 106
 107 #if     NCONSFEED > 0
 108 #if     MACH_KDB
 109         if (console_is_serial()) {
 110                 return;
 111         }
 112 #endif  /* MACH_KDB */
 113
 114         s = splhigh();
 115         simple_lock(&cons_feed_lock);
 116         if (cons_feed_count == 0) {
 117                 simple_unlock(&cons_feed_lock);
 118                 splx(s);
 119                 return;
 120         }
 121         cons_feed_count = 0;
 122         simple_unlock(&cons_feed_lock);
 123         splx(s);
 124
 125         do {
 126                 c = getc(&cons_feed_cb);
 127                 if (c == -1)
 128                         break;
 129                 cnputc(c);
 130         } while (1);
 131 #endif /* NCONSFEED > 0 */
 132 }
 133
 134 io_return_t
 135 console_feed_read(
 136         dev_t           dev,
 137         io_req_t        ior)
 138 {
 139         spl_t           s;
 140         kern_return_t   rc;
 141         int             count;
 142
 143         rc = device_read_alloc(ior, (vm_size_t) ior->io_count);
 144         if (rc != KERN_SUCCESS)
 145                 return rc;
 146
 147         s = splhigh();
 148         simple_lock(&cons_feed_lock);
 149
 150         ior->io_residual = ior->io_count;
 151
 152         count = q_to_b(&cons_feed_cb, (char *) ior->io_data, ior->io_count);
 153         if (count == 0) {
 154                 if (ior->io_mode & D_NOWAIT) {
 155                         rc = D_WOULD_BLOCK;
 156                 }
 157                 if (cons_feed_queued == NULL) {
 158                         ior->io_done = cons_feed_read_done;
 159                         cons_feed_queued = ior;
 160                         rc = D_IO_QUEUED;
 161                 } else {
 162                         /* Can't queue multiple read requests yet */
 163                         rc = D_INVALID_OPERATION;
 164                 }
 165                 simple_unlock(&cons_feed_lock);
 166                 splx(s);
 167                 return rc;
 168         }
 169
 170         simple_unlock(&cons_feed_lock);
 171         splx(s);
 172
 173         ior->io_residual -= count;
 174
 175         iodone(ior);
 176
 177         if (ior->io_op & IO_SYNC) {
 178                 iowait(ior);
 179         }
 180
 181         return D_SUCCESS;
 182 }
 183
 184 /* Called when data is ready and there's a queued-up read waiting */
 185 boolean_t cons_feed_read_done(io_req_t ior)
 186 {
 187         spl_t   s;
 188         int     count;
 189
 190         s = splhigh();
 191         simple_lock(&cons_feed_lock);
 192
 193         count = q_to_b(&cons_feed_cb, (char *) ior->io_data, ior->io_count);
 194         if (count == 0) {
 195                 if (cons_feed_queued == NULL) {
 196                         ior->io_done = cons_feed_read_done;
 197                         cons_feed_queued = ior;
 198                 }
 199                 simple_unlock(&cons_feed_lock);
 200                 splx(s);
 201                 return FALSE;
 202         }
 203
 204         simple_unlock(&cons_feed_lock);
 205         splx(s);
 206
 207         ior->io_residual -= count;
 208         ds_read_done(ior);
 209
 210         return TRUE;
 211 }
 212
 213 /* This routine is called from putc() - it should return TRUE if
 214  * the character should be passed on to a physical console, FALSE
 215  * if the feed has intercepted the character. It may be called from
 216  * under interrupt (even splhigh)
 217  */
 218
 219 boolean_t console_feed_putc(char c)
 220 {
 221         spl_t           s;
 222         io_req_t        ior;
 223         boolean_t       retval;
 224
 225 #if     MACH_KDB
 226         if (db_active) {
 227                 return TRUE;
 228         }
 229 #endif  /* MACH_KDB */
 230
 231         retval=TRUE;    /* TRUE : character should be displayed now */
 232         if (!cons_feed_count) {
 233                 return TRUE;
 234         }
 235         s = splhigh();
 236         simple_lock(&cons_feed_lock);
 237         if (!cons_feed_count) {
 238                 simple_unlock(&cons_feed_lock);
 239                 splx(s);
 240                 return TRUE;
 241         }
 242         /* queue up the data if we can */
 243         if (!putc(c, &cons_feed_cb)) {
 244                 /* able to stock the character */
 245                 retval = FALSE;
 246         }
 247         if (cons_feed_queued != NULL) {
 248                 /* Queued up request - service it */
 249                 ior = cons_feed_queued;
 250                 cons_feed_queued = NULL;
 251                 simple_unlock(&cons_feed_lock);
 252                 splx(s);
 253                 iodone(ior);
 254                 retval=FALSE;
 255         } else {
 256                 simple_unlock(&cons_feed_lock);
 257                 splx(s);
 258         }
 259         return retval;
 260 }