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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.  */
  140. int ipc_irq_register(answerbox_t *box, inr_t inr, devno_t devno,
  141.     unative_t method, irq_code_t *ucode)
  142. {
  143.     ipl_t ipl;
  144.     irq_code_t *code;
  145.     irq_t *irq;
  146.     link_t *hlp;
  147.     unative_t key[] = {
  148.         (unative_t) inr,
  149.         (unative_t) devno
  150.     };
  151.    
  152.     if (ucode) {
  153.         code = code_from_uspace(ucode);
  154.         if (!code)
  155.             return EBADMEM;
  156.     } else {
  157.         code = NULL;
  158.     }
  159.    
  160.     /*
  161.      * Allocate and populate the IRQ structure.
  162.      */
  163.     irq = malloc(sizeof(irq_t), 0);
  164.     irq_initialize(irq);
  165.     irq->devno = devno;
  166.     irq->inr = inr;
  167.     irq->claim = ipc_irq_top_half_claim;
  168.     irq->handler = ipc_irq_top_half_handler;
  169.     irq->notif_cfg.notify = true;
  170.     irq->notif_cfg.answerbox = box;
  171.     irq->notif_cfg.method = method;
  172.     irq->notif_cfg.code = code;
  173.     irq->notif_cfg.counter = 0;
  174.    
  175.     /*
  176.      * Enlist the IRQ structure in the uspace IRQ hash table and the
  177.      * answerbox's list.
  178.      */
  179.     ipl = interrupts_disable();
  180.     spinlock_lock(&irq_uspace_hash_table_lock);
  181.     hlp = hash_table_find(&irq_uspace_hash_table, key);
  182.     if (hlp) {
  183.         irq_t *hirq __attribute__((unused))
  184.             = hash_table_get_instance(hlp, irq_t, link);
  185.        
  186.         /* hirq is locked */
  187.         spinlock_unlock(&hirq->lock);
  188.         code_free(code);
  189.         spinlock_unlock(&irq_uspace_hash_table_lock);
  190.         free(irq);
  191.         interrupts_restore(ipl);
  192.         return EEXISTS;
  193.     }
  194.    
  195.     spinlock_lock(&irq->lock);  /* Not really necessary, but paranoid */
  196.     spinlock_lock(&box->irq_lock);
  197.     hash_table_insert(&irq_uspace_hash_table, key, &irq->link);
  198.     list_append(&irq->notif_cfg.link, &box->irq_head);
  199.     spinlock_unlock(&box->irq_lock);
  200.     spinlock_unlock(&irq->lock);
  201.     spinlock_unlock(&irq_uspace_hash_table_lock);
  202.    
  203.     interrupts_restore(ipl);
  204.     return EOK;
  205. }
  206.  
  207. /** Unregister task from IRQ notification.
  208.  *
  209.  * @param box       Answerbox associated with the notification.
  210.  * @param inr       IRQ number.
  211.  * @param devno     Device number.
  212.  */
  213. int ipc_irq_unregister(answerbox_t *box, inr_t inr, devno_t devno)
  214. {
  215.     ipl_t ipl;
  216.     unative_t key[] = {
  217.         (unative_t) inr,
  218.         (unative_t) devno
  219.     };
  220.     link_t *lnk;
  221.     irq_t *irq;
  222.  
  223.     ipl = interrupts_disable();
  224.     spinlock_lock(&irq_uspace_hash_table_lock);
  225.     lnk = hash_table_find(&irq_uspace_hash_table, key);
  226.     if (!lnk) {
  227.         spinlock_unlock(&irq_uspace_hash_table_lock);
  228.         interrupts_restore(ipl);
  229.         return ENOENT;
  230.     }
  231.     irq = hash_table_get_instance(lnk, irq_t, link);
  232.     /* irq is locked */
  233.     spinlock_lock(&box->irq_lock);
  234.    
  235.     ASSERT(irq->notif_cfg.answerbox == box);
  236.    
  237.     /* Free up the pseudo code and associated structures. */
  238.     code_free(irq->notif_cfg.code);
  239.  
  240.     /* Remove the IRQ from the answerbox's list. */
  241.     list_remove(&irq->notif_cfg.link);
  242.  
  243.     /*
  244.      * We need to drop the IRQ lock now because hash_table_remove() will try
  245.      * to reacquire it. That basically violates the natural locking order,
  246.      * but a deadlock in hash_table_remove() is prevented by the fact that
  247.      * we already held the IRQ lock and didn't drop the hash table lock in
  248.      * the meantime.
  249.      */
  250.     spinlock_unlock(&irq->lock);
  251.  
  252.     /* Remove the IRQ from the uspace IRQ hash table. */
  253.     hash_table_remove(&irq_uspace_hash_table, key, 2);
  254.    
  255.     spinlock_unlock(&irq_uspace_hash_table_lock);
  256.     spinlock_unlock(&box->irq_lock);
  257.    
  258.     /* Free up the IRQ structure. */
  259.     free(irq);
  260.    
  261.     interrupts_restore(ipl);
  262.     return EOK;
  263. }
  264.  
  265.  
  266. /** Disconnect all IRQ notifications from an answerbox.
  267.  *
  268.  * This function is effective because the answerbox contains
  269.  * list of all irq_t structures that are registered to
  270.  * send notifications to it.
  271.  *
  272.  * @param box       Answerbox for which we want to carry out the cleanup.
  273.  */
  274. void ipc_irq_cleanup(answerbox_t *box)
  275. {
  276.     ipl_t ipl;
  277.    
  278. loop:
  279.     ipl = interrupts_disable();
  280.     spinlock_lock(&irq_uspace_hash_table_lock);
  281.     spinlock_lock(&box->irq_lock);
  282.    
  283.     while (box->irq_head.next != &box->irq_head) {
  284.         link_t *cur = box->irq_head.next;
  285.         irq_t *irq;
  286.         DEADLOCK_PROBE_INIT(p_irqlock);
  287.         unative_t key[2];
  288.        
  289.         irq = list_get_instance(cur, irq_t, notif_cfg.link);
  290.         if (!spinlock_trylock(&irq->lock)) {
  291.             /*
  292.              * Avoid deadlock by trying again.
  293.              */
  294.             spinlock_unlock(&box->irq_lock);
  295.             spinlock_unlock(&irq_uspace_hash_table_lock);
  296.             interrupts_restore(ipl);
  297.             DEADLOCK_PROBE(p_irqlock, DEADLOCK_THRESHOLD);
  298.             goto loop;
  299.         }
  300.         key[0] = irq->inr;
  301.         key[1] = irq->devno;
  302.        
  303.        
  304.         ASSERT(irq->notif_cfg.answerbox == box);
  305.        
  306.         /* Unlist from the answerbox. */
  307.         list_remove(&irq->notif_cfg.link);
  308.        
  309.         /* Free up the pseudo code and associated structures. */
  310.         code_free(irq->notif_cfg.code);
  311.        
  312.         /*
  313.          * We need to drop the IRQ lock now because hash_table_remove()
  314.          * will try to reacquire it. That basically violates the natural
  315.          * locking order, but a deadlock in hash_table_remove() is
  316.          * prevented by the fact that we already held the IRQ lock and
  317.          * didn't drop the hash table lock in the meantime.
  318.          */
  319.         spinlock_unlock(&irq->lock);
  320.        
  321.         /* Remove from the hash table. */
  322.         hash_table_remove(&irq_uspace_hash_table, key, 2);
  323.        
  324.         free(irq);
  325.     }
  326.    
  327.     spinlock_unlock(&box->irq_lock);
  328.     spinlock_unlock(&irq_uspace_hash_table_lock);
  329.     interrupts_restore(ipl);
  330. }
  331.  
  332. /** Add a call to the proper answerbox queue.
  333.  *
  334.  * Assume irq->lock is locked.
  335.  *
  336.  * @param irq       IRQ structure referencing the target answerbox.
  337.  * @param call      IRQ notification call.
  338.  */
  339. static void send_call(irq_t *irq, call_t *call)
  340. {
  341.     spinlock_lock(&irq->notif_cfg.answerbox->irq_lock);
  342.     list_append(&call->link, &irq->notif_cfg.answerbox->irq_notifs);
  343.     spinlock_unlock(&irq->notif_cfg.answerbox->irq_lock);
  344.        
  345.     waitq_wakeup(&irq->notif_cfg.answerbox->wq, WAKEUP_FIRST);
  346. }
  347.  
  348. /** Apply the top-half pseudo code to find out whether to accept the IRQ or not.
  349.  *
  350.  * @param irq       IRQ structure.
  351.  *
  352.  * @return      IRQ_ACCEPT if the interrupt is accepted by the
  353.  *          pseudocode. IRQ_DECLINE otherwise.
  354.  */
  355. irq_ownership_t ipc_irq_top_half_claim(irq_t *irq)
  356. {
  357.     unsigned int i;
  358.     unative_t dstval;
  359.     irq_code_t *code = irq->notif_cfg.code;
  360.     unative_t *scratch = irq->notif_cfg.scratch;
  361.  
  362.    
  363.     if (!irq->notif_cfg.notify)
  364.         return IRQ_DECLINE;
  365.    
  366.     if (!code)
  367.         return IRQ_DECLINE;
  368.    
  369.     for (i = 0; i < code->cmdcount; i++) {
  370.         unsigned int srcarg = code->cmds[i].srcarg;
  371.         unsigned int dstarg = code->cmds[i].dstarg;
  372.        
  373.         if (srcarg >= IPC_CALL_LEN)
  374.             break;
  375.         if (dstarg >= IPC_CALL_LEN)
  376.             break;
  377.    
  378.         switch (code->cmds[i].cmd) {
  379.         case CMD_PIO_READ_8:
  380.             dstval = pio_read_8((ioport8_t *) code->cmds[i].addr);
  381.             if (dstarg)
  382.                 scratch[dstarg] = dstval;
  383.             break;
  384.         case CMD_PIO_READ_16:
  385.             dstval = pio_read_16((ioport16_t *) code->cmds[i].addr);
  386.             if (dstarg)
  387.                 scratch[dstarg] = dstval;
  388.             break;
  389.         case CMD_PIO_READ_32:
  390.             dstval = pio_read_32((ioport32_t *) code->cmds[i].addr);
  391.             if (dstarg)
  392.                 scratch[dstarg] = dstval;
  393.             break;
  394.         case CMD_PIO_WRITE_8:
  395.             pio_write_8((ioport8_t *) code->cmds[i].addr,
  396.                 (uint8_t) code->cmds[i].value);
  397.             break;
  398.         case CMD_PIO_WRITE_16:
  399.             pio_write_16((ioport16_t *) code->cmds[i].addr,
  400.                 (uint16_t) code->cmds[i].value);
  401.             break;
  402.         case CMD_PIO_WRITE_32:
  403.             pio_write_32((ioport32_t *) code->cmds[i].addr,
  404.                 (uint32_t) code->cmds[i].value);
  405.             break;
  406.         case CMD_BTEST:
  407.             if (srcarg && dstarg) {
  408.                 dstval = scratch[srcarg] & code->cmds[i].value;
  409.                 scratch[dstarg] = dstval;
  410.             }
  411.             break;
  412.         case CMD_PREDICATE:
  413.             if (srcarg && !scratch[srcarg]) {
  414.                 i += code->cmds[i].value;
  415.                 continue;
  416.             }
  417.             break;
  418.         case CMD_ACCEPT:
  419.             return IRQ_ACCEPT;
  420.             break;
  421.         case CMD_DECLINE:
  422.         default:
  423.             return IRQ_DECLINE;
  424.         }
  425.     }
  426.    
  427.     return IRQ_DECLINE;
  428. }
  429.  
  430.  
  431. /* IRQ top-half handler.
  432.  *
  433.  * We expect interrupts to be disabled and the irq->lock already held.
  434.  *
  435.  * @param irq       IRQ structure.
  436.  */
  437. void ipc_irq_top_half_handler(irq_t *irq)
  438. {
  439.     ASSERT(irq);
  440.  
  441.     if (irq->notif_cfg.answerbox) {
  442.         call_t *call;
  443.  
  444.         call = ipc_call_alloc(FRAME_ATOMIC);
  445.         if (!call)
  446.             return;
  447.        
  448.         call->flags |= IPC_CALL_NOTIF;
  449.         /* Put a counter to the message */
  450.         call->priv = ++irq->notif_cfg.counter;
  451.  
  452.         /* Set up args */
  453.         IPC_SET_METHOD(call->data, irq->notif_cfg.method);
  454.         IPC_SET_ARG1(call->data, irq->notif_cfg.scratch[1]);
  455.         IPC_SET_ARG2(call->data, irq->notif_cfg.scratch[2]);
  456.         IPC_SET_ARG3(call->data, irq->notif_cfg.scratch[3]);
  457.         IPC_SET_ARG4(call->data, irq->notif_cfg.scratch[4]);
  458.         IPC_SET_ARG5(call->data, irq->notif_cfg.scratch[5]);
  459.  
  460.         send_call(irq, call);
  461.     }
  462. }
  463.  
  464. /** Send notification message.
  465.  *
  466.  * @param irq       IRQ structure.
  467.  * @param a1        Driver-specific payload argument.
  468.  * @param a2        Driver-specific payload argument.
  469.  * @param a3        Driver-specific payload argument.
  470.  * @param a4        Driver-specific payload argument.
  471.  * @param a5        Driver-specific payload argument.
  472.  */
  473. void ipc_irq_send_msg(irq_t *irq, unative_t a1, unative_t a2, unative_t a3,
  474.     unative_t a4, unative_t a5)
  475. {
  476.     call_t *call;
  477.  
  478.     spinlock_lock(&irq->lock);
  479.  
  480.     if (irq->notif_cfg.answerbox) {
  481.         call = ipc_call_alloc(FRAME_ATOMIC);
  482.         if (!call) {
  483.             spinlock_unlock(&irq->lock);
  484.             return;
  485.         }
  486.         call->flags |= IPC_CALL_NOTIF;
  487.         /* Put a counter to the message */
  488.         call->priv = ++irq->notif_cfg.counter;
  489.  
  490.         IPC_SET_METHOD(call->data, irq->notif_cfg.method);
  491.         IPC_SET_ARG1(call->data, a1);
  492.         IPC_SET_ARG2(call->data, a2);
  493.         IPC_SET_ARG3(call->data, a3);
  494.         IPC_SET_ARG4(call->data, a4);
  495.         IPC_SET_ARG5(call->data, a5);
  496.        
  497.         send_call(irq, call);
  498.     }
  499.     spinlock_unlock(&irq->lock);
  500. }
  501.  
  502. /** @}
  503.  */
  504.