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/*
* \brief Hardware-interrupt support
* \author Christian Helmuth <ch12@os.inf.tu-dresden.de>
* \date 2007-02-12
*
*
*
* XXX Consider support for IRQ_HANDLED and friends (linux/irqreturn.h)
*/
/* Linux */
#include <linux/interrupt.h>
#include <linux/string.h> /* memset() */
/* local */
#include "dde26.h"
#include "local.h"
/* dummy */
irq_cpustat_t irq_stat[CONFIG_NR_CPUS];
/**
* IRQ handling data
*/
static struct dde_irq
{
unsigned irq; /* IRQ number */
unsigned count; /* usage count */
int shared; /* shared IRQ */
struct ddekit_thread *thread; /* DDEKit interrupt thread */
struct irqaction *action; /* Linux IRQ action */
struct dde_irq *next; /* next DDE IRQ */
} *used_irqs;
static void irq_thread_init(void *p) {
l4dde26_process_add_worker(); }
extern ddekit_sem_t *dde_softirq_sem;
static void irq_handler(void *arg)
{
struct dde_irq *irq = arg;
struct irqaction *action;
#if 0
DEBUG_MSG("irq 0x%x", irq->irq);
#endif
/* interrupt occurred - call all handlers */
for (action = irq->action; action; action = action->next) {
irqreturn_t r = action->handler(action->irq, action->dev_id);
#if 0
DEBUG_MSG("return: %s", r == IRQ_HANDLED ? "IRQ_HANDLED" : r == IRQ_NONE ? "IRQ_NONE" : "??");
#endif
}
/* upon return we check for pending soft irqs */
if (local_softirq_pending())
ddekit_sem_up(dde_softirq_sem);
}
/*****************************
** IRQ handler bookkeeping **
*****************************/
/**
* Claim IRQ
*
* \return usage counter or negative error code
*
* FIXME list locking
* FIXME are there more races?
*/
static int claim_irq(struct irqaction *action)
{
int shared = action->flags & IRQF_SHARED ? 1 : 0;
struct dde_irq *irq;
/* check if IRQ already used */
for (irq = used_irqs; irq; irq = irq->next)
if (irq->irq == action->irq) break;
/* we have to setup IRQ handling */
if (!irq) {
/* allocate and initalize new descriptor */
irq = ddekit_simple_malloc(sizeof(*irq));
if (!irq) return -ENOMEM;
memset(irq, 0, sizeof(*irq));
irq->irq = action->irq;
irq->shared = shared;
irq->next = used_irqs;
used_irqs = irq;
/* attach to interrupt */
irq->thread = ddekit_interrupt_attach(irq->irq,
irq->shared,
irq_thread_init,
irq_handler,
(void *)irq);
if (!irq->thread) {
used_irqs = irq->next;
ddekit_simple_free(irq);
return -EBUSY;
}
}
/* does desciptor allow our new handler? */
if ((!irq->shared || !shared) && irq->action) return -EBUSY;
/* add handler */
irq->count++;
action->next = irq->action;
irq->action = action;
return irq->count;
}
/**
* Free previously claimed IRQ
*
* \return usage counter or negative error code
*/
static struct irqaction *release_irq(unsigned irq_num, void *dev_id)
{
struct dde_irq *prev_irq, *irq;
/* check if IRQ already used */
for (prev_irq = 0, irq = used_irqs; irq;
prev_irq = irq, irq = irq->next)
if (irq->irq == irq_num) break;
if (!irq) return 0;
struct irqaction *prev_action, *action;
for (prev_action = 0, action = irq->action; action;
prev_action = action, action = action->next)
if (action->dev_id == dev_id) break;
if (!action) return 0;
/* dequeue action from irq */
if (prev_action)
prev_action->next = action->next;
else
irq->action = action->next;
/* dequeue irq from used_irqs list and free structure,
if no more actions available */
if (!irq->action) {
if (prev_irq)
prev_irq->next = irq->next;
else
used_irqs = irq->next;
/* detach from interrupt */
ddekit_interrupt_detach(irq->irq);
ddekit_simple_free(irq);
}
return action;
}
/***************
** Linux API **
***************/
/**
* Request interrupt
*
* \param irq interrupt number
* \param handler interrupt handler -> top half
* \param flags interrupt handling flags (SA_SHIRQ, ...)
* \param dev_name device name
* \param dev_id cookie passed back to handler
*
* \return 0 on success; error code otherwise
*
* \todo FIXME consider locking!
*/
int request_irq(unsigned int irq, irq_handler_t handler,
unsigned long flags, const char *dev_name, void *dev_id)
{
if (!handler) return -EINVAL;
/* facilitate Linux irqaction for this handler */
struct irqaction *irq_action = ddekit_simple_malloc(sizeof(*irq_action));
if (!irq_action) return -ENOMEM;
memset(irq_action, 0, sizeof(*irq_action));
irq_action->handler = handler;
irq_action->flags = flags;
irq_action->name = dev_name;
irq_action->dev_id = dev_id;
irq_action->irq = irq;
/* attach to IRQ */
int err = claim_irq(irq_action);
if (err < 0) return err;
return 0;
}
/** Release Interrupt
* \ingroup mod_irq
*
* \param irq interrupt number
* \param dev_id cookie passed back to handler
*
*/
void free_irq(unsigned int irq, void *dev_id)
{
struct irqaction *irq_action = release_irq(irq, dev_id);
if (irq_action)
ddekit_simple_free(irq_action);
}
void disable_irq(unsigned int irq)
{
ddekit_interrupt_disable(irq);
}
void disable_irq_nosync(unsigned int irq)
{
/*
* Note:
* In contrast to the _nosync semantics, DDEKit's
* disable definitely waits until a currently executed
* IRQ handler terminates.
*/
ddekit_interrupt_disable(irq);
}
void enable_irq(unsigned int irq)
{
ddekit_interrupt_enable(irq);
}
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