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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 redirector. |
| * |
| * 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. |
| */ |
| |
| #include <ddi/irq.h> |
| #include <adt/hash_table.h> |
| #include <arch/types.h> |
| #include <typedefs.h> |
| #include <synch/spinlock.h> |
| #include <arch.h> |
| |
| /** |
| * 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, 1, &irq_lin_ops); |
| else |
| hash_table_create(&irq_hash_table, chains, 1, &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); |
| irq->inr = -1; |
| irq->devno = -1; |
| irq->notif = 0; |
| irq->trigger = 0; |
| irq->claim = NULL; |
| irq->handler = NULL; |
| irq->arg = NULL; |
| } |
| |
| /** 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; |
| |
| ipl = interrupts_disable(); |
| spinlock_lock(&irq_hash_table_lock); |
| hash_table_insert(&irq_hash_table, (void *) &irq->inr, &irq->link); |
| spinlock_unlock(&irq_hash_table_lock); |
| interrupts_restore(ipl); |
| } |
| |
| /** Dispatch the IRQ. |
| * |
| * @param inr Interrupt number (aka inr or irq). |
| * |
| * @return IRQ structure of the respective device or NULL. |
| */ |
| irq_t *irq_dispatch(inr_t inr) |
| { |
| ipl_t ipl; |
| link_t *lnk; |
| |
| ipl = interrupts_disable(); |
| spinlock_lock(&irq_hash_table_lock); |
| |
| lnk = hash_table_find(&irq_hash_table, (void *) &inr); |
| if (lnk) { |
| irq_t *irq; |
| |
| irq = hash_table_get_instance(lnk, irq_t, link); |
| |
| spinlock_unlock(&irq_hash_table_lock); |
| interrupts_restore(ipl); |
| return irq; |
| } |
| |
| spinlock_unlock(&irq_hash_table_lock); |
| interrupts_restore(ipl); |
| |
| 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. |
| * |
| * @param key Pointer to INR. |
| * |
| * @return Index into the hash table. |
| */ |
| index_t irq_ht_hash(unative_t *key) |
| { |
| inr_t *inr = (inr_t *) key; |
| return *inr % irq_hash_table.entries; |
| } |
| |
| /** Compare hash table element with a key. |
| * |
| * As usually, we do sort of a hack here. |
| * Even when the key matches the inr member, |
| * we ask the device to either accept |
| * or decline to service the interrupt. |
| * |
| * @param key Pointer to key (i.e. inr). |
| * @param keys This is 1. |
| * @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; |
| |
| return ((irq->inr == *inr) && (irq->claim() == IRQ_ACCEPT)); |
| } |
| |
| /** 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 INR. |
| * |
| * @return Index into the hash table. |
| */ |
| index_t irq_lin_hash(unative_t *key) |
| { |
| inr_t *inr = (inr_t *) key; |
| return *inr; |
| } |
| |
| /** Compare hash table element with a key. |
| * |
| * As usually, we do sort of a hack here. |
| * We don't compare the inr member with |
| * the key because we know that there are |
| * no collision between different keys. |
| * We only ask the device to either accept |
| * or decline to service the interrupt. |
| * |
| * @param key Pointer to key (i.e. inr). |
| * @param keys This is 1. |
| * @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); |
| |
| return (irq->claim() == IRQ_ACCEPT); |
| } |
| |
| /** @} |
| */ |