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  1. /*
  2.  * Copyright (c) 2006 Ondrej Palkovsky
  3.  * Copyright (c) 2006 Jakub Jermar
  4.  * All rights reserved.
  5.  *
  6.  * Redistribution and use in source and binary forms, with or without
  7.  * modification, are permitted provided that the following conditions
  8.  * are met:
  9.  *
  10.  * - Redistributions of source code must retain the above copyright
  11.  *   notice, this list of conditions and the following disclaimer.
  12.  * - Redistributions in binary form must reproduce the above copyright
  13.  *   notice, this list of conditions and the following disclaimer in the
  14.  *   documentation and/or other materials provided with the distribution.
  15.  * - The name of the author may not be used to endorse or promote products
  16.  *   derived from this software without specific prior written permission.
  17.  *
  18.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28.  */
  29.  
  30. /** @addtogroup genericipc
  31.  * @{
  32.  */
  33. /**
  34.  * @file
  35.  * @brief IRQ notification framework.
  36.  *
  37.  * This framework allows applications to register to receive a notification
  38.  * when interrupt is detected. The application may provide a simple 'top-half'
  39.  * handler as part of its registration, which can perform simple operations
  40.  * (read/write port/memory, add information to notification ipc message).
  41.  *
  42.  * The structure of a notification message is as follows:
  43.  * - METHOD: method as registered by the SYS_IPC_REGISTER_IRQ syscall
  44.  * - ARG1: payload modified by a 'top-half' handler
  45.  * - ARG2: payload modified by a 'top-half' handler
  46.  * - ARG3: payload modified by a 'top-half' handler
  47.  * - ARG4: payload modified by a 'top-half' handler
  48.  * - ARG5: payload modified by a 'top-half' handler
  49.  * - in_phone_hash: interrupt counter (may be needed to assure correct order
  50.  *         in multithreaded drivers)
  51.  *
  52.  * Note on synchronization for ipc_irq_register(), ipc_irq_unregister(),
  53.  * ipc_irq_cleanup() and IRQ handlers:
  54.  *
  55.  *   By always taking all of the uspace IRQ hash table lock, IRQ structure lock
  56.  *   and answerbox lock, we can rule out race conditions between the
  57.  *   registration functions and also the cleanup function. Thus the observer can
  58.  *   either see the IRQ structure present in both the hash table and the
  59.  *   answerbox list or absent in both. Views in which the IRQ structure would be
  60.  *   linked in the hash table but not in the answerbox list, or vice versa, are
  61.  *   not possible.
  62.  *
  63.  *   By always taking the hash table lock and the IRQ structure lock, we can
  64.  *   rule out a scenario in which we would free up an IRQ structure, which is
  65.  *   still referenced by, for example, an IRQ handler. The locking scheme forces
  66.  *   us to lock the IRQ structure only after any progressing IRQs on that
  67.  *   structure are finished. Because we hold the hash table lock, we prevent new
  68.  *   IRQs from taking new references to the IRQ structure.
  69.  */
  70.  
  71. #include <arch.h>
  72. #include <mm/slab.h>
  73. #include <errno.h>
  74. #include <ddi/irq.h>
  75. #include <ipc/ipc.h>
  76. #include <ipc/irq.h>
  77. #include <syscall/copy.h>
  78. #include <console/console.h>
  79. #include <print.h>
  80.  
  81. /** Free the top-half pseudocode.
  82.  *
  83.  * @param code      Pointer to the top-half pseudocode.
  84.  */
  85. static void code_free(irq_code_t *code)
  86. {
  87.     if (code) {
  88.         free(code->cmds);
  89.         free(code);
  90.     }
  91. }
  92.  
  93. /** Copy the top-half pseudocode from userspace into the kernel.
  94.  *
  95.  * @param ucode     Userspace address of the top-half pseudocode.
  96.  *
  97.  * @return      Kernel address of the copied pseudocode.
  98.  */
  99. static irq_code_t *code_from_uspace(irq_code_t *ucode)
  100. {
  101.     irq_code_t *code;
  102.     irq_cmd_t *ucmds;
  103.     int rc;
  104.  
  105.     code = malloc(sizeof(*code), 0);
  106.     rc = copy_from_uspace(code, ucode, sizeof(*code));
  107.     if (rc != 0) {
  108.         free(code);
  109.         return NULL;
  110.     }
  111.    
  112.     if (code->cmdcount > IRQ_MAX_PROG_SIZE) {
  113.         free(code);
  114.         return NULL;
  115.     }
  116.     ucmds = code->cmds;
  117.     code->cmds = malloc(sizeof(code->cmds[0]) * code->cmdcount, 0);
  118.     rc = copy_from_uspace(code->cmds, ucmds,
  119.         sizeof(code->cmds[0]) * code->cmdcount);
  120.     if (rc != 0) {
  121.         free(code->cmds);
  122.         free(code);
  123.         return NULL;
  124.     }
  125.  
  126.     return code;
  127. }
  128.  
  129. /** Register an answerbox as a receiving end for IRQ notifications.
  130.  *
  131.  * @param box       Receiving answerbox.
  132.  * @param inr       IRQ number.
  133.  * @param devno     Device number.
  134.  * @param method    Method to be associated with the notification.
  135.  * @param ucode     Uspace pointer to top-half pseudocode.
  136.  *
  137.  * @return      EBADMEM, ENOENT or EEXISTS on failure or 0 on success.
  138.  */
  139. int ipc_irq_register(answerbox_t *box, inr_t inr, devno_t devno,
  140.     unative_t method, irq_code_t *ucode)
  141. {
  142.     ipl_t ipl;
  143.     irq_code_t *code;
  144.     irq_t *irq;
  145.     link_t *hlp;
  146.     unative_t key[] = {
  147.         (unative_t) inr,
  148.         (unative_t) devno
  149.     };
  150.  
  151.     if (ucode) {
  152.         code = code_from_uspace(ucode);
  153.         if (!code)
  154.             return EBADMEM;
  155.     } else {
  156.         code = NULL;
  157.     }
  158.  
  159.     /*
  160.      * Allocate and populate the IRQ structure.
  161.      */
  162.     irq = malloc(sizeof(irq_t), 0);
  163.     irq_initialize(irq);
  164.     irq->devno = devno;
  165.     irq->inr = inr;
  166.     irq->claim = ipc_irq_top_half_claim;
  167.     irq->handler = ipc_irq_top_half_handler;
  168.     irq->notif_cfg.notify = true;
  169.     irq->notif_cfg.answerbox = box;
  170.     irq->notif_cfg.method = method;
  171.     irq->notif_cfg.code = code;
  172.     irq->notif_cfg.counter = 0;
  173.  
  174.     /*
  175.      * Enlist the IRQ structure in the uspace IRQ hash table and the
  176.      * answerbox's list.
  177.      */
  178.     ipl = interrupts_disable();
  179.     spinlock_lock(&irq_uspace_hash_table_lock);
  180.     hlp = hash_table_find(&irq_uspace_hash_table, key);
  181.     if (hlp) {
  182.         irq_t *hirq = hash_table_get_instance(hlp, irq_t, link);
  183.         /* hirq is locked */
  184.         spinlock_unlock(&hirq->lock);
  185.         code_free(code);
  186.         spinlock_unlock(&irq_uspace_hash_table_lock);
  187.         free(irq);
  188.         interrupts_restore(ipl);
  189.         return EEXISTS;
  190.     }
  191.     spinlock_lock(&irq->lock);  /* not really necessary, but paranoid */
  192.     spinlock_lock(&box->irq_lock);
  193.     hash_table_insert(&irq_uspace_hash_table, key, &irq->link);
  194.     list_append(&irq->notif_cfg.link, &box->irq_head);
  195.     spinlock_unlock(&box->irq_lock);
  196.     spinlock_unlock(&irq->lock);
  197.     spinlock_unlock(&irq_uspace_hash_table_lock);
  198.  
  199.     interrupts_restore(ipl);
  200.     return EOK;
  201. }
  202.  
  203. /** Unregister task from IRQ notification.
  204.  *
  205.  * @param box       Answerbox associated with the notification.
  206.  * @param inr       IRQ number.
  207.  * @param devno     Device number.
  208.  */
  209. int ipc_irq_unregister(answerbox_t *box, inr_t inr, devno_t devno)
  210. {
  211.     ipl_t ipl;
  212.     unative_t key[] = {
  213.         (unative_t) inr,
  214.         (unative_t) devno
  215.     };
  216.     link_t *lnk;
  217.     irq_t *irq;
  218.  
  219.     ipl = interrupts_disable();
  220.     spinlock_lock(&irq_uspace_hash_table_lock);
  221.     lnk = hash_table_find(&irq_uspace_hash_table, key);
  222.     if (!lnk) {
  223.         spinlock_unlock(&irq_uspace_hash_table_lock);
  224.         interrupts_restore(ipl);
  225.         return ENOENT;
  226.     }
  227.     irq = hash_table_get_instance(lnk, irq_t, link);
  228.     /* irq is locked */
  229.     spinlock_lock(&box->irq_lock);
  230.    
  231.     ASSERT(irq->notif_cfg.answerbox == box);
  232.    
  233.     /* Free up the pseudo code and associated structures. */
  234.     code_free(irq->notif_cfg.code);
  235.  
  236.     /* Remove the IRQ from the answerbox's list. */
  237.     list_remove(&irq->notif_cfg.link);
  238.  
  239.     /*
  240.      * We need to drop the IRQ lock now because hash_table_remove() will try
  241.      * to reacquire it. That basically violates the natural locking order,
  242.      * but a deadlock in hash_table_remove() is prevented by the fact that
  243.      * we already held the IRQ lock and didn't drop the hash table lock in
  244.      * the meantime.
  245.      */
  246.     spinlock_unlock(&irq->lock);
  247.  
  248.     /* Remove the IRQ from the uspace IRQ hash table. */
  249.     hash_table_remove(&irq_uspace_hash_table, key, 2);
  250.    
  251.     spinlock_unlock(&irq_uspace_hash_table_lock);
  252.     spinlock_unlock(&box->irq_lock);
  253.    
  254.     /* Free up the IRQ structure. */
  255.     free(irq);
  256.    
  257.     interrupts_restore(ipl);
  258.     return EOK;
  259. }
  260.  
  261.  
  262. /** Disconnect all IRQ notifications from an answerbox.
  263.  *
  264.  * This function is effective because the answerbox contains
  265.  * list of all irq_t structures that are registered to
  266.  * send notifications to it.
  267.  *
  268.  * @param box       Answerbox for which we want to carry out the cleanup.
  269.  */
  270. void ipc_irq_cleanup(answerbox_t *box)
  271. {
  272.     ipl_t ipl;
  273.    
  274. loop:
  275.     ipl = interrupts_disable();
  276.     spinlock_lock(&irq_uspace_hash_table_lock);
  277.     spinlock_lock(&box->irq_lock);
  278.    
  279.     while (box->irq_head.next != &box->irq_head) {
  280.         link_t *cur = box->irq_head.next;
  281.         irq_t *irq;
  282.         DEADLOCK_PROBE_INIT(p_irqlock);
  283.         unative_t key[2];
  284.        
  285.         irq = list_get_instance(cur, irq_t, notif_cfg.link);
  286.         if (!spinlock_trylock(&irq->lock)) {
  287.             /*
  288.              * Avoid deadlock by trying again.
  289.              */
  290.             spinlock_unlock(&box->irq_lock);
  291.             spinlock_unlock(&irq_uspace_hash_table_lock);
  292.             interrupts_restore(ipl);
  293.             DEADLOCK_PROBE(p_irqlock, DEADLOCK_THRESHOLD);
  294.             goto loop;
  295.         }
  296.         key[0] = irq->inr;
  297.         key[1] = irq->devno;
  298.        
  299.        
  300.         ASSERT(irq->notif_cfg.answerbox == box);
  301.        
  302.         /* Unlist from the answerbox. */
  303.         list_remove(&irq->notif_cfg.link);
  304.        
  305.         /* Free up the pseudo code and associated structures. */
  306.         code_free(irq->notif_cfg.code);
  307.        
  308.         /*
  309.          * We need to drop the IRQ lock now because hash_table_remove()
  310.          * will try to reacquire it. That basically violates the natural
  311.          * locking order, but a deadlock in hash_table_remove() is
  312.          * prevented by the fact that we already held the IRQ lock and
  313.          * didn't drop the hash table lock in the meantime.
  314.          */
  315.         spinlock_unlock(&irq->lock);
  316.        
  317.         /* Remove from the hash table. */
  318.         hash_table_remove(&irq_uspace_hash_table, key, 2);
  319.        
  320.         free(irq);
  321.     }
  322.    
  323.     spinlock_unlock(&box->irq_lock);
  324.     spinlock_unlock(&irq_uspace_hash_table_lock);
  325.     interrupts_restore(ipl);
  326. }
  327.  
  328. /** Add a call to the proper answerbox queue.
  329.  *
  330.  * Assume irq->lock is locked.
  331.  *
  332.  * @param irq       IRQ structure referencing the target answerbox.
  333.  * @param call      IRQ notification call.
  334.  */
  335. static void send_call(irq_t *irq, call_t *call)
  336. {
  337.     spinlock_lock(&irq->notif_cfg.answerbox->irq_lock);
  338.     list_append(&call->link, &irq->notif_cfg.answerbox->irq_notifs);
  339.     spinlock_unlock(&irq->notif_cfg.answerbox->irq_lock);
  340.        
  341.     waitq_wakeup(&irq->notif_cfg.answerbox->wq, WAKEUP_FIRST);
  342. }
  343.  
  344. /** Apply the top-half pseudo code to find out whether to accept the IRQ or not.
  345.  *
  346.  * @param irq       IRQ structure.
  347.  *
  348.  * @return      IRQ_ACCEPT if the interrupt is accepted by the
  349.  *          pseudocode. IRQ_DECLINE otherwise.
  350.  */
  351. irq_ownership_t ipc_irq_top_half_claim(irq_t *irq)
  352. {
  353.     unsigned int i;
  354.     unative_t dstval;
  355.     irq_code_t *code = irq->notif_cfg.code;
  356.     unative_t *scratch = irq->notif_cfg.scratch;
  357.  
  358.    
  359.     if (!irq->notif_cfg.notify)
  360.         return IRQ_DECLINE;
  361.    
  362.     if (!code)
  363.         return IRQ_DECLINE;
  364.    
  365.     for (i = 0; i < code->cmdcount; i++) {
  366.         unsigned int srcarg = code->cmds[i].srcarg;
  367.         unsigned int dstarg = code->cmds[i].dstarg;
  368.        
  369.         if (srcarg >= IPC_CALL_LEN)
  370.             break;
  371.         if (dstarg >= IPC_CALL_LEN)
  372.             break;
  373.    
  374.         switch (code->cmds[i].cmd) {
  375.         case CMD_PIO_READ_8:
  376.             dstval = pio_read_8((ioport8_t *) code->cmds[i].addr);
  377.             if (dstarg)
  378.                 scratch[dstarg] = dstval;
  379.             break;
  380.         case CMD_PIO_READ_16:
  381.             dstval = pio_read_16((ioport16_t *) code->cmds[i].addr);
  382.             if (dstarg)
  383.                 scratch[dstarg] = dstval;
  384.             break;
  385.         case CMD_PIO_READ_32:
  386.             dstval = pio_read_32((ioport32_t *) code->cmds[i].addr);
  387.             if (dstarg)
  388.                 scratch[dstarg] = dstval;
  389.             break;
  390.         case CMD_PIO_WRITE_8:
  391.             pio_write_8((ioport8_t *) code->cmds[i].addr,
  392.                 (uint8_t) code->cmds[i].value);
  393.             break;
  394.         case CMD_PIO_WRITE_16:
  395.             pio_write_16((ioport16_t *) code->cmds[i].addr,
  396.                 (uint16_t) code->cmds[i].value);
  397.             break;
  398.         case CMD_PIO_WRITE_32:
  399.             pio_write_32((ioport32_t *) code->cmds[i].addr,
  400.                 (uint32_t) code->cmds[i].value);
  401.             break;
  402.         case CMD_BTEST:
  403.             if (srcarg && dstarg) {
  404.                 dstval = scratch[srcarg] & code->cmds[i].value;
  405.                 scratch[dstarg] = dstval;
  406.             }
  407.             break;
  408.         case CMD_PREDICATE:
  409.             if (srcarg && !scratch[srcarg]) {
  410.                 i += code->cmds[i].value;
  411.                 continue;
  412.             }
  413.             break;
  414.         case CMD_ACCEPT:
  415.             return IRQ_ACCEPT;
  416.             break;
  417.         case CMD_DECLINE:
  418.         default:
  419.             return IRQ_DECLINE;
  420.         }
  421.     }
  422.    
  423.     return IRQ_DECLINE;
  424. }
  425.  
  426.  
  427. /* IRQ top-half handler.
  428.  *
  429.  * We expect interrupts to be disabled and the irq->lock already held.
  430.  *
  431.  * @param irq       IRQ structure.
  432.  */
  433. void ipc_irq_top_half_handler(irq_t *irq)
  434. {
  435.     ASSERT(irq);
  436.  
  437.     if (irq->notif_cfg.answerbox) {
  438.         call_t *call;
  439.  
  440.         call = ipc_call_alloc(FRAME_ATOMIC);
  441.         if (!call)
  442.             return;
  443.        
  444.         call->flags |= IPC_CALL_NOTIF;
  445.         /* Put a counter to the message */
  446.         call->priv = ++irq->notif_cfg.counter;
  447.  
  448.         /* Set up args */
  449.         IPC_SET_METHOD(call->data, irq->notif_cfg.method);
  450.         IPC_SET_ARG1(call->data, irq->notif_cfg.scratch[1]);
  451.         IPC_SET_ARG2(call->data, irq->notif_cfg.scratch[2]);
  452.         IPC_SET_ARG3(call->data, irq->notif_cfg.scratch[3]);
  453.         IPC_SET_ARG4(call->data, irq->notif_cfg.scratch[4]);
  454.         IPC_SET_ARG5(call->data, irq->notif_cfg.scratch[5]);
  455.  
  456.         send_call(irq, call);
  457.     }
  458. }
  459.  
  460. /** Send notification message.
  461.  *
  462.  * @param irq       IRQ structure.
  463.  * @param a1        Driver-specific payload argument.
  464.  * @param a2        Driver-specific payload argument.
  465.  * @param a3        Driver-specific payload argument.
  466.  * @param a4        Driver-specific payload argument.
  467.  * @param a5        Driver-specific payload argument.
  468.  */
  469. void ipc_irq_send_msg(irq_t *irq, unative_t a1, unative_t a2, unative_t a3,
  470.     unative_t a4, unative_t a5)
  471. {
  472.     call_t *call;
  473.  
  474.     spinlock_lock(&irq->lock);
  475.  
  476.     if (irq->notif_cfg.answerbox) {
  477.         call = ipc_call_alloc(FRAME_ATOMIC);
  478.         if (!call) {
  479.             spinlock_unlock(&irq->lock);
  480.             return;
  481.         }
  482.         call->flags |= IPC_CALL_NOTIF;
  483.         /* Put a counter to the message */
  484.         call->priv = ++irq->notif_cfg.counter;
  485.  
  486.         IPC_SET_METHOD(call->data, irq->notif_cfg.method);
  487.         IPC_SET_ARG1(call->data, a1);
  488.         IPC_SET_ARG2(call->data, a2);
  489.         IPC_SET_ARG3(call->data, a3);
  490.         IPC_SET_ARG4(call->data, a4);
  491.         IPC_SET_ARG5(call->data, a5);
  492.        
  493.         send_call(irq, call);
  494.     }
  495.     spinlock_unlock(&irq->lock);
  496. }
  497.  
  498. /** @}
  499.  */
  500.