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| /* |
| * Copyright (c) 2006 Jakub Jermar |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** @addtogroup genericddi |
| * @{ |
| */ |
| /** |
| * @file |
| * @brief IRQ dispatcher. |
| * |
| * This file provides means of connecting IRQs with particular |
| * devices and logic for dispatching interrupts to IRQ handlers |
| * defined by those devices. |
| * |
| * This code is designed to support: |
| * - multiple devices sharing single IRQ |
| * - multiple IRQs per signle device |
| * |
| * |
| * Note about architectures. |
| * |
| * Some architectures has the term IRQ well defined. Examples |
| * of such architectures include amd64, ia32 and mips32. Some |
| * other architectures, such as sparc64, don't use the term |
| * at all. In those cases, we boldly step forward and define what |
| * an IRQ is. |
| * |
| * The implementation is generic enough and still allows the |
| * architectures to use the hardware layout effectively. |
| * For instance, on amd64 and ia32, where there is only 16 |
| * IRQs, the irq_hash_table can be optimized to a one-dimensional |
| * array. Next, when it is known that the IRQ numbers (aka INR's) |
| * are unique, the claim functions can always return IRQ_ACCEPT. |
| * |
| * |
| * Note about the irq_hash_table. |
| * |
| * The hash table is configured to use two keys: inr and devno. |
| * However, the hash index is computed only from inr. Moreover, |
| * if devno is -1, the match is based on the return value of |
| * the claim() function instead of on devno. |
| */ |
| |
| #include <ddi/irq.h> |
| #include <adt/hash_table.h> |
| #include <arch/types.h> |
| #include <synch/spinlock.h> |
| #include <arch.h> |
| |
| #define KEY_INR 0 |
| #define KEY_DEVNO 1 |
| |
| /** |
| * Spinlock protecting the hash table. |
| * This lock must be taken only when interrupts are disabled. |
| */ |
| SPINLOCK_INITIALIZE(irq_hash_table_lock); |
| static hash_table_t irq_hash_table; |
| |
| /** |
| * Hash table operations for cases when we know that |
| * there will be collisions between different keys. |
| */ |
| static index_t irq_ht_hash(unative_t *key); |
| static bool irq_ht_compare(unative_t *key, count_t keys, link_t *item); |
| |
| static hash_table_operations_t irq_ht_ops = { |
| .hash = irq_ht_hash, |
| .compare = irq_ht_compare, |
| .remove_callback = NULL /* not used */ |
| }; |
| |
| /** |
| * Hash table operations for cases when we know that |
| * there will be no collisions between different keys. |
| * However, there might be still collisions among |
| * elements with single key (sharing of one IRQ). |
| */ |
| static index_t irq_lin_hash(unative_t *key); |
| static bool irq_lin_compare(unative_t *key, count_t keys, link_t *item); |
| |
| static hash_table_operations_t irq_lin_ops = { |
| .hash = irq_lin_hash, |
| .compare = irq_lin_compare, |
| .remove_callback = NULL /* not used */ |
| }; |
| |
| /** Initialize IRQ subsystem. |
| * |
| * @param inrs Numbers of unique IRQ numbers or INRs. |
| * @param chains Number of chains in the hash table. |
| */ |
| void irq_init(count_t inrs, count_t chains) |
| { |
| /* |
| * Be smart about the choice of the hash table operations. |
| * In cases in which inrs equals the requested number of |
| * chains (i.e. where there is no collision between |
| * different keys), we can use optimized set of operations. |
| */ |
| if (inrs == chains) |
| hash_table_create(&irq_hash_table, chains, 2, &irq_lin_ops); |
| else |
| hash_table_create(&irq_hash_table, chains, 2, &irq_ht_ops); |
| } |
| |
| /** Initialize one IRQ structure. |
| * |
| * @param irq Pointer to the IRQ structure to be initialized. |
| * |
| */ |
| void irq_initialize(irq_t *irq) |
| { |
| link_initialize(&irq->link); |
| spinlock_initialize(&irq->lock, "irq.lock"); |
| irq->preack = false; |
| irq->inr = -1; |
| irq->devno = -1; |
| irq->trigger = (irq_trigger_t) 0; |
| irq->claim = NULL; |
| irq->handler = NULL; |
| irq->arg = NULL; |
| irq->notif_cfg.notify = false; |
| irq->notif_cfg.answerbox = NULL; |
| irq->notif_cfg.code = NULL; |
| irq->notif_cfg.method = 0; |
| irq->notif_cfg.counter = 0; |
| link_initialize(&irq->notif_cfg.link); |
| } |
| |
| /** Register IRQ for device. |
| * |
| * The irq structure must be filled with information |
| * about the interrupt source and with the claim() |
| * function pointer and irq_handler() function pointer. |
| * |
| * @param irq IRQ structure belonging to a device. |
| */ |
| void irq_register(irq_t *irq) |
| { |
| ipl_t ipl; |
| unative_t key[] = { |
| (unative_t) irq->inr, |
| (unative_t) irq->devno |
| }; |
| |
| ipl = interrupts_disable(); |
| spinlock_lock(&irq_hash_table_lock); |
| hash_table_insert(&irq_hash_table, key, &irq->link); |
| spinlock_unlock(&irq_hash_table_lock); |
| interrupts_restore(ipl); |
| } |
| |
| /** Dispatch the IRQ. |
| * |
| * We assume this function is only called from interrupt |
| * context (i.e. that interrupts are disabled prior to |
| * this call). |
| * |
| * This function attempts to lookup a fitting IRQ |
| * structure. In case of success, return with interrupts |
| * disabled and holding the respective structure. |
| * |
| * @param inr Interrupt number (aka inr or irq). |
| * |
| * @return IRQ structure of the respective device or NULL. |
| */ |
| irq_t *irq_dispatch_and_lock(inr_t inr) |
| { |
| link_t *lnk; |
| unative_t key[] = { |
| (unative_t) inr, |
| (unative_t) -1 /* search will use claim() instead of devno */ |
| }; |
| |
| spinlock_lock(&irq_hash_table_lock); |
| |
| lnk = hash_table_find(&irq_hash_table, key); |
| if (lnk) { |
| irq_t *irq; |
| |
| irq = hash_table_get_instance(lnk, irq_t, link); |
| |
| spinlock_unlock(&irq_hash_table_lock); |
| return irq; |
| } |
| |
| spinlock_unlock(&irq_hash_table_lock); |
| |
| return NULL; |
| } |
| |
| /** Find the IRQ structure corresponding to inr and devno. |
| * |
| * This functions attempts to lookup the IRQ structure |
| * corresponding to its arguments. On success, this |
| * function returns with interrups disabled, holding |
| * the lock of the respective IRQ structure. |
| * |
| * This function assumes interrupts are already disabled. |
| * |
| * @param inr INR being looked up. |
| * @param devno Devno being looked up. |
| * |
| * @return Locked IRQ structure on success or NULL on failure. |
| */ |
| irq_t *irq_find_and_lock(inr_t inr, devno_t devno) |
| { |
| link_t *lnk; |
| unative_t keys[] = { |
| (unative_t) inr, |
| (unative_t) devno |
| }; |
| |
| spinlock_lock(&irq_hash_table_lock); |
| |
| lnk = hash_table_find(&irq_hash_table, keys); |
| if (lnk) { |
| irq_t *irq; |
| |
| irq = hash_table_get_instance(lnk, irq_t, link); |
| |
| spinlock_unlock(&irq_hash_table_lock); |
| return irq; |
| } |
| |
| spinlock_unlock(&irq_hash_table_lock); |
| |
| return NULL; |
| } |
| |
| /** Compute hash index for the key. |
| * |
| * This function computes hash index into |
| * the IRQ hash table for which there |
| * can be collisions between different |
| * INRs. |
| * |
| * The devno is not used to compute the hash. |
| * |
| * @param key The first of the keys is inr and the second is devno or -1. |
| * |
| * @return Index into the hash table. |
| */ |
| index_t irq_ht_hash(unative_t key[]) |
| { |
| inr_t inr = (inr_t) key[KEY_INR]; |
| return inr % irq_hash_table.entries; |
| } |
| |
| /** Compare hash table element with a key. |
| * |
| * There are two things to note about this function. |
| * First, it is used for the more complex architecture setup |
| * in which there are way too many interrupt numbers (i.e. inr's) |
| * to arrange the hash table so that collisions occur only |
| * among same inrs of different devnos. So the explicit check |
| * for inr match must be done. |
| * Second, if devno is -1, the second key (i.e. devno) is not |
| * used for the match and the result of the claim() function |
| * is used instead. |
| * |
| * This function assumes interrupts are already disabled. |
| * |
| * @param key Keys (i.e. inr and devno). |
| * @param keys This is 2. |
| * @param item The item to compare the key with. |
| * |
| * @return True on match or false otherwise. |
| */ |
| bool irq_ht_compare(unative_t key[], count_t keys, link_t *item) |
| { |
| irq_t *irq = hash_table_get_instance(item, irq_t, link); |
| inr_t inr = (inr_t) key[KEY_INR]; |
| devno_t devno = (devno_t) key[KEY_DEVNO]; |
| |
| bool rv; |
| |
| spinlock_lock(&irq->lock); |
| if (devno == -1) { |
| /* Invoked by irq_dispatch_and_lock(). */ |
| rv = ((irq->inr == inr) && (irq->claim() == IRQ_ACCEPT)); |
| } else { |
| /* Invoked by irq_find_and_lock(). */ |
| rv = ((irq->inr == inr) && (irq->devno == devno)); |
| } |
| |
| /* unlock only on non-match */ |
| if (!rv) |
| spinlock_unlock(&irq->lock); |
| |
| return rv; |
| } |
| |
| /** Compute hash index for the key. |
| * |
| * This function computes hash index into |
| * the IRQ hash table for which there |
| * are no collisions between different |
| * INRs. |
| * |
| * @param key The first of the keys is inr and the second is devno or -1. |
| * |
| * @return Index into the hash table. |
| */ |
| index_t irq_lin_hash(unative_t key[]) |
| { |
| inr_t inr = (inr_t) key[KEY_INR]; |
| return inr; |
| } |
| |
| /** Compare hash table element with a key. |
| * |
| * There are two things to note about this function. |
| * First, it is used for the less complex architecture setup |
| * in which there are not too many interrupt numbers (i.e. inr's) |
| * to arrange the hash table so that collisions occur only |
| * among same inrs of different devnos. So the explicit check |
| * for inr match is not done. |
| * Second, if devno is -1, the second key (i.e. devno) is not |
| * used for the match and the result of the claim() function |
| * is used instead. |
| * |
| * This function assumes interrupts are already disabled. |
| * |
| * @param key Keys (i.e. inr and devno). |
| * @param keys This is 2. |
| * @param item The item to compare the key with. |
| * |
| * @return True on match or false otherwise. |
| */ |
| bool irq_lin_compare(unative_t key[], count_t keys, link_t *item) |
| { |
| irq_t *irq = list_get_instance(item, irq_t, link); |
| devno_t devno = (devno_t) key[KEY_DEVNO]; |
| bool rv; |
| |
| spinlock_lock(&irq->lock); |
| if (devno == -1) { |
| /* Invoked by irq_dispatch_and_lock() */ |
| rv = (irq->claim() == IRQ_ACCEPT); |
| } else { |
| /* Invoked by irq_find_and_lock() */ |
| rv = (irq->devno == devno); |
| } |
| |
| /* unlock only on non-match */ |
| if (!rv) |
| spinlock_unlock(&irq->lock); |
| |
| return rv; |
| } |
| |
| /** @} |
| */ |