/*
* 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 kernel_generic_ddi
* @{
*/
/**
* @file
* @brief IRQ dispatcher
*
* This file provides means of connecting IRQs with respective device drivers
* and logic for dispatching interrupts to IRQ handlers defined by those
* drivers.
*/
#include <ddi/irq.h>
#include <adt/hash.h>
#include <adt/hash_table.h>
#include <mm/slab.h>
#include <typedefs.h>
#include <synch/spinlock.h>
#include <console/console.h>
#include <interrupt.h>
#include <memw.h>
#include <arch.h>
slab_cache_t *irq_cache = NULL;
/** Spinlock protecting the kernel IRQ hash table
*
* This lock must be taken only when interrupts are disabled.
*
*/
IRQ_SPINLOCK_STATIC_INITIALIZE(irq_kernel_hash_table_lock);
/** The kernel IRQ hash table. */
static hash_table_t irq_kernel_hash_table;
/** Spinlock protecting the uspace IRQ hash table
*
* This lock must be taken only when interrupts are disabled.
*
*/
IRQ_SPINLOCK_INITIALIZE(irq_uspace_hash_table_lock);
/** The uspace IRQ hash table */
hash_table_t irq_uspace_hash_table;
static size_t irq_ht_hash(const ht_link_t *);
static size_t irq_ht_key_hash(const void *);
static bool irq_ht_equal(const ht_link_t *, const ht_link_t *);
static bool irq_ht_key_equal(const void *, const ht_link_t *);
static const hash_table_ops_t irq_ht_ops = {
.hash = irq_ht_hash,
.key_hash = irq_ht_key_hash,
.equal = irq_ht_equal,
.key_equal = irq_ht_key_equal
};
/** Last valid INR */
inr_t last_inr = 0;
/** Initialize IRQ subsystem
*
* @param inrs Numbers of unique IRQ numbers or INRs.
* @param chains Number of buckets in the hash table.
*
*/
void irq_init(size_t inrs, size_t chains)
{
last_inr = inrs - 1;
irq_cache = slab_cache_create("irq_t", sizeof(irq_t), 0, NULL, NULL,
FRAME_ATOMIC);
assert(irq_cache);
hash_table_create(&irq_uspace_hash_table, chains, 0, &irq_ht_ops);
hash_table_create(&irq_kernel_hash_table, chains, 0, &irq_ht_ops);
}
/** Initialize one IRQ structure
*
* @param irq Pointer to the IRQ structure to be initialized.
*
*/
void irq_initialize(irq_t *irq)
{
memsetb(irq, sizeof(irq_t), 0);
irq_spinlock_initialize(&irq->lock, "irq.lock");
irq->inr = -1;
irq_initialize_arch(irq);
}
/** Register IRQ for device
*
* The irq structure must be filled with information about the interrupt source
* and with the claim() function pointer and handler() function pointer.
*
* @param irq IRQ structure belonging to a device.
*
*/
void irq_register(irq_t *irq)
{
irq_spinlock_lock(&irq_kernel_hash_table_lock, true);
irq_spinlock_lock(&irq->lock, false);
hash_table_insert(&irq_kernel_hash_table, &irq->link);
irq_spinlock_unlock(&irq->lock, false);
irq_spinlock_unlock(&irq_kernel_hash_table_lock, true);
}
/** Search and lock an IRQ hash table */
static irq_t *
irq_dispatch_and_lock_table(hash_table_t *h, irq_spinlock_t *l, inr_t inr)
{
irq_spinlock_lock(l, false);
ht_link_t *first = hash_table_find(h, &inr);
for (ht_link_t *lnk = first; lnk;
lnk = hash_table_find_next(h, first, lnk)) {
irq_t *irq = hash_table_get_inst(lnk, irq_t, link);
irq_spinlock_lock(&irq->lock, false);
if (irq->claim(irq) == IRQ_ACCEPT) {
/* leave irq locked */
irq_spinlock_unlock(l, false);
return irq;
}
irq_spinlock_unlock(&irq->lock, false);
}
irq_spinlock_unlock(l, false);
return NULL;
}
/** 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
* @return NULL if no IRQ structure found
*
*/
irq_t *irq_dispatch_and_lock(inr_t inr)
{
/*
* If the kernel console override is on, then try first the kernel
* handlers and eventually fall back to uspace handlers.
*
* In the usual case the uspace handlers have precedence.
*/
if (console_override) {
irq_t *irq = irq_dispatch_and_lock_table(&irq_kernel_hash_table,
&irq_kernel_hash_table_lock, inr);
if (irq)
return irq;
return irq_dispatch_and_lock_table(&irq_uspace_hash_table,
&irq_uspace_hash_table_lock, inr);
}
irq_t *irq = irq_dispatch_and_lock_table(&irq_uspace_hash_table,
&irq_uspace_hash_table_lock, inr);
if (irq)
return irq;
return irq_dispatch_and_lock_table(&irq_kernel_hash_table,
&irq_kernel_hash_table_lock, inr);
}
/** Return the hash of the key stored in the item. */
size_t irq_ht_hash(const ht_link_t *item)
{
irq_t *irq = hash_table_get_inst(item, irq_t, link);
return hash_mix(irq->inr);
}
/** Return the hash of the key. */
size_t irq_ht_key_hash(const void *key)
{
const inr_t *inr = key;
return hash_mix(*inr);
}
/** Return true if the items have the same lookup key. */
bool irq_ht_equal(const ht_link_t *item1, const ht_link_t *item2)
{
irq_t *irq1 = hash_table_get_inst(item1, irq_t, link);
irq_t *irq2 = hash_table_get_inst(item2, irq_t, link);
return irq1->inr == irq2->inr;
}
/** Return true if the key is equal to the item's lookup key. */
bool irq_ht_key_equal(const void *key, const ht_link_t *item)
{
const inr_t *inr = key;
irq_t *irq = hash_table_get_inst(item, irq_t, link);
return irq->inr == *inr;
}
/** @}
*/