/*
* Definitions used in MIPS MT SMTC "Interprocessor Interrupt" code.
*/
#ifndef __ASM_SMTC_IPI_H
#define __ASM_SMTC_IPI_H

#include <linux/spinlock.h>

//#define SMTC_IPI_DEBUG

#ifdef SMTC_IPI_DEBUG
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#endif /* SMTC_IPI_DEBUG */

/*
* An IPI "message"
*/

struct smtc_ipi {
struct smtc_ipi *flink;
int type;
void *arg;
int dest;
#ifdef SMTC_IPI_DEBUG
int sender;
long stamp;
#endif /* SMTC_IPI_DEBUG */
};

/*
* Defined IPI Types
*/

#define LINUX_SMP_IPI 1
#define SMTC_CLOCK_TICK 2
#define IRQ_AFFINITY_IPI 3

/*
* A queue of IPI messages
*/

struct smtc_ipi_q {
struct smtc_ipi *head;
spinlock_t lock;
struct smtc_ipi *tail;
int depth;
int resched_flag; /* reschedule already queued */
};

static inline void smtc_ipi_nq(struct smtc_ipi_q *q, struct smtc_ipi *p)
{
unsigned long flags;

spin_lock_irqsave(&q->lock, flags);
if (q->head == NULL)
q->head = q->tail = p;
else
q->tail->flink = p;
p->flink = NULL;
q->tail = p;
q->depth++;
#ifdef SMTC_IPI_DEBUG
p->sender = read_c0_tcbind();
p->stamp = read_c0_count();
#endif /* SMTC_IPI_DEBUG */
spin_unlock_irqrestore(&q->lock, flags);
}

static inline struct smtc_ipi *__smtc_ipi_dq(struct smtc_ipi_q *q)
{
struct smtc_ipi *p;

if (q->head == NULL)
p = NULL;
else {
p = q->head;
q->head = q->head->flink;
q->depth--;
/* Arguably unnecessary, but leaves queue cleaner */
if (q->head == NULL)
q->tail = NULL;
}

return p;
}

static inline struct smtc_ipi *smtc_ipi_dq(struct smtc_ipi_q *q)
{
unsigned long flags;
struct smtc_ipi *p;

spin_lock_irqsave(&q->lock, flags);
p = __smtc_ipi_dq(q);
spin_unlock_irqrestore(&q->lock, flags);

return p;
}

static inline void smtc_ipi_req(struct smtc_ipi_q *q, struct smtc_ipi *p)
{
unsigned long flags;

spin_lock_irqsave(&q->lock, flags);
if (q->head == NULL) {
q->head = q->tail = p;
p->flink = NULL;
} else {
p->flink = q->head;
q->head = p;
}
q->depth++;
spin_unlock_irqrestore(&q->lock, flags);
}

static inline int smtc_ipi_qdepth(struct smtc_ipi_q *q)
{
unsigned long flags;
int retval;

spin_lock_irqsave(&q->lock, flags);
retval = q->depth;
spin_unlock_irqrestore(&q->lock, flags);
return retval;
}

extern void smtc_send_ipi(int cpu, int type, unsigned int action);

#endif /* __ASM_SMTC_IPI_H */