src/patches/fcdsl-singlelock.patch

   1 # patch found at http://freiburg.linux.de/~zeisberg/howtos/fritzcarddsl.html
   2 diff -u -r fritz.old/src.drv/driver.c fritz/src.drv/driver.c
   3 --- fritz.old/src.drv/driver.c  Tue Jul  8 00:02:00 2003
   4 +++ fritz/src.drv/driver.c      Fri Nov  7 14:21:49 2003
   5 @@ -18,6 +18,10 @@
   6   * http://www.opensource.org/licenses/lgpl-license.html
   7   *
   8   * Contact: AVM GmbH, Alt-Moabit 95, 10559 Berlin, Germany, email: info@avm.de
   9 + *
  10 + * Mon Oct 20 22:43:31 2003
  11 + * Modified by Joerg Lehrke to improve locking
  12 + *
  13   */
  14
  15  #include <asm/io.h>
  16 @@ -57,6 +61,8 @@
  17  #include "dbgif.h"
  18  #endif
  19
  20 +#undef SINGLE_LOCK
  21 +
  22  #if defined (LOG_MESSAGES)
  23  # define mlog          log
  24  #else
  25 @@ -107,7 +113,11 @@
  26  struct capi_ctr *              capi_controller[2]      = { NULL, NULL } ;
  27  static bundle_t                        ctrl_context[2];
  28  static per_ctrl_t              ctrl_params[2];
  29 +#if defined (SINGLE_LOCK)
  30 +# define stack_lock qt_lock
  31 +#else
  32  static spinlock_t              stack_lock              = SPIN_LOCK_UNLOCKED;
  33 +#endif
  34  static atomic_t                        rx_flag                 = ATOMIC_INIT (0);
  35  static atomic_t                        tx_flag                 = ATOMIC_INIT (0);
  36  static unsigned long           qt_flags;
  37 @@ -1080,7 +1090,7 @@
  38  } /* remove_ctrl */
  39
  40  /*---------------------------------------------------------------------------*\
  41 -\*-L-------------------------------------------------------------------------*/
  42 +\*---------------------------------------------------------------------------*/
  43  void lock (void) {
  44         unsigned long   local_flags;
  45
  46 @@ -1098,7 +1108,7 @@
  47  } /* unlock */
  48
  49  /*---------------------------------------------------------------------------*\
  50 -\*-C-------------------------------------------------------------------------*/
  51 +\*---------------------------------------------------------------------------*/
  52  static inline int in_critical (void) {
  53
  54         return (0 < atomic_read (&crit_count));
  55 @@ -1108,17 +1118,16 @@
  56  \*---------------------------------------------------------------------------*/
  57  static inline void check (void) {
  58         unsigned long   flags;
  59 -       spinlock_t      chk_lock = SPIN_LOCK_UNLOCKED;
  60
  61         if (atomic_xchg (&rx_flag, 0)) {
  62 -               spin_lock_irqsave (&chk_lock, flags);
  63 +               spin_lock_irqsave (&stack_lock, flags);
  64                 rx_handler (capi_card);
  65 -               spin_unlock_irqrestore (&chk_lock, flags);
  66 +               spin_unlock_irqrestore (&stack_lock, flags);
  67         }
  68         if (atomic_xchg (&tx_flag, 0)) {
  69 -               spin_lock_irqsave (&chk_lock, flags);
  70 +               spin_lock_irqsave (&stack_lock, flags);
  71                 tx_handler (capi_card);
  72 -               spin_unlock_irqrestore (&chk_lock, flags);
  73 +               spin_unlock_irqrestore (&stack_lock, flags);
  74         }
  75  } /* check */
  76
  77 @@ -1640,7 +1649,7 @@
  78         return ncci_data_buffer (capi_card->appls, appp, ncci, handle);
  79  } /* data_block */
  80
  81 -/*-S-------------------------------------------------------------------------*\
  82 +/*---------------------------------------------------------------------------*\
  83  \*---------------------------------------------------------------------------*/
  84  static void scheduler_control (unsigned ena) {
  85         int     enabled = (int) ena;
  86 @@ -1662,6 +1671,7 @@
  87  /*---------------------------------------------------------------------------*\
  88  \*---------------------------------------------------------------------------*/
  89  static int sched_thread (void * arg) {
  90 +        unsigned long  flags;
  91
  92         UNUSED_ARG (arg);
  93         daemonize ();
  94 @@ -1692,6 +1702,7 @@
  95                         continue;
  96                 }
  97                 /* Body of thread, invoke scheduler */
  98 +               local_irq_save(flags);
  99                 if (spin_trylock (&stack_lock)) {
 100                         os_timer_poll ();
 101                         assert (capi_lib->cm_schedule);
 102 @@ -1700,6 +1711,7 @@
 103                         }
 104                         spin_unlock (&stack_lock);
 105                 }
 106 +               local_irq_restore(flags);
 107         }
 108         log ("Scheduler thread stopped.\n");
 109         up (&hotplug);
 110 @@ -1802,17 +1814,22 @@
 111  /*---------------------------------------------------------------------------*\
 112  \*---------------------------------------------------------------------------*/
 113  static void tx_task (unsigned long data) {
 114 -
 115 +        unsigned long  flags;
 116 +
 117         UNUSED_ARG (data);
 118         if (in_critical ()) {
 119                 atomic_set (&tx_flag, 1);
 120                 kick_scheduler ();
 121 -       } else if (spin_trylock (&stack_lock)) {
 122 -               tx_handler (capi_card);
 123 -               spin_unlock (&stack_lock);
 124         } else {
 125 -               atomic_set (&tx_flag, 1);
 126 -               kick_scheduler ();
 127 +               local_irq_save(flags);
 128 +               if (spin_trylock (&stack_lock)) {
 129 +                       tx_handler (capi_card);
 130 +                       spin_unlock (&stack_lock);
 131 +               } else {
 132 +                       atomic_set (&tx_flag, 1);
 133 +                       kick_scheduler ();
 134 +               }
 135 +               local_irq_restore(flags);
 136         }
 137  } /* tx_task */
 138
 139 @@ -1865,17 +1882,22 @@
 140  /*---------------------------------------------------------------------------*\
 141  \*---------------------------------------------------------------------------*/
 142  static void rx_task (unsigned long data) {
 143 +        unsigned long  flags;
 144
 145         UNUSED_ARG (data);
 146         if (in_critical ()) {
 147                 atomic_set (&rx_flag, 1);
 148                 kick_scheduler ();
 149 -       } else if (spin_trylock (&stack_lock)) {
 150 -               rx_handler (capi_card);
 151 -               spin_unlock (&stack_lock);
 152         } else {
 153 -               atomic_set (&rx_flag, 1);
 154 -               kick_scheduler ();
 155 +               local_irq_save(flags);
 156 +               if (spin_trylock (&stack_lock)) {
 157 +                       rx_handler (capi_card);
 158 +                       spin_unlock (&stack_lock);
 159 +               } else {
 160 +                       atomic_set (&rx_flag, 1);
 161 +                       kick_scheduler ();
 162 +               }
 163 +               local_irq_restore(flags);
 164         }
 165  } /* rx_task */
 166
 167 @@ -1894,6 +1916,7 @@
 168         if (capi_card != (card_p) args) {
 169                 return;
 170         }
 171 +       spin_lock (&stack_lock);
 172         while (0 != ((flags = PEEK (capi_card->io_base + INT_CTL)) & CARD_PCI_INT_ASSERT)) {
 173  #if !defined (NDEBUG)
 174                 ++count;
 175 @@ -1906,6 +1929,7 @@
 176                 assert ((PEEK (capi_card->io_base + INT_CTL)
 177                                 & ~(CARD_PCI_INT_ASSERT | CARD_PCI_INT_ISASSERTED)) != 0);
 178                 if (!atomic_read (&link_open)) {
 179 +                       spin_unlock (&stack_lock);
 180                         return;
 181                 }
 182                 tx_flag = PEEK (capi_card->io_base + XFER_TOTM_STATUS) == TM_READY;
 183 @@ -1920,6 +1944,7 @@
 184                 }
 185         }
 186         info (0 == (PEEK (capi_card->io_base + INT_CTL) & CARD_PCI_INT_ASSERT));
 187 +       spin_unlock (&stack_lock);
 188  } /* irq_handler */
 189
 190  /*---------------------------------------------------------------------------*\