1/*
  2 * Definitions used in MIPS MT SMTC "Interprocessor Interrupt" code.
  3 */
  4#ifndef __ASM_SMTC_IPI_H
  5#define __ASM_SMTC_IPI_H
  6
  7#include <linux/spinlock.h>
  8
  9//#define SMTC_IPI_DEBUG
 10
 11#ifdef SMTC_IPI_DEBUG
 12#include <asm/mipsregs.h>
 13#include <asm/mipsmtregs.h>
 14#endif /* SMTC_IPI_DEBUG */
 15
 16/*
 17 * An IPI "message"
 18 */
 19
 20struct smtc_ipi {
 21	struct smtc_ipi *flink;
 22	int type;
 23	void *arg;
 24	int dest;
 25#ifdef	SMTC_IPI_DEBUG
 26	int sender;
 27	long stamp;
 28#endif /* SMTC_IPI_DEBUG */
 29};
 30
 31/*
 32 * Defined IPI Types
 33 */
 34
 35#define LINUX_SMP_IPI 1
 36#define SMTC_CLOCK_TICK 2
 37#define IRQ_AFFINITY_IPI 3
 38
 39/*
 40 * A queue of IPI messages
 41 */
 42
 43struct smtc_ipi_q {
 44	struct smtc_ipi *head;
 45	spinlock_t lock;
 46	struct smtc_ipi *tail;
 47	int depth;
 48	int resched_flag;	/* reschedule already queued */
 49};
 50
 51static inline void smtc_ipi_nq(struct smtc_ipi_q *q, struct smtc_ipi *p)
 52{
 53	unsigned long flags;
 54
 55	spin_lock_irqsave(&q->lock, flags);
 56	if (q->head == NULL)
 57		q->head = q->tail = p;
 58	else
 59		q->tail->flink = p;
 60	p->flink = NULL;
 61	q->tail = p;
 62	q->depth++;
 63#ifdef	SMTC_IPI_DEBUG
 64	p->sender = read_c0_tcbind();
 65	p->stamp = read_c0_count();
 66#endif /* SMTC_IPI_DEBUG */
 67	spin_unlock_irqrestore(&q->lock, flags);
 68}
 69
 70static inline struct smtc_ipi *__smtc_ipi_dq(struct smtc_ipi_q *q)
 71{
 72	struct smtc_ipi *p;
 73
 74	if (q->head == NULL)
 75		p = NULL;
 76	else {
 77		p = q->head;
 78		q->head = q->head->flink;
 79		q->depth--;
 80		/* Arguably unnecessary, but leaves queue cleaner */
 81		if (q->head == NULL)
 82			q->tail = NULL;
 83	}
 84
 85	return p;
 86}
 87
 88static inline struct smtc_ipi *smtc_ipi_dq(struct smtc_ipi_q *q)
 89{
 90	unsigned long flags;
 91	struct smtc_ipi *p;
 92
 93	spin_lock_irqsave(&q->lock, flags);
 94	p = __smtc_ipi_dq(q);
 95	spin_unlock_irqrestore(&q->lock, flags);
 96
 97	return p;
 98}
 99
100static inline void smtc_ipi_req(struct smtc_ipi_q *q, struct smtc_ipi *p)
101{
102	unsigned long flags;
103
104	spin_lock_irqsave(&q->lock, flags);
105	if (q->head == NULL) {
106		q->head = q->tail = p;
107		p->flink = NULL;
108	} else {
109		p->flink = q->head;
110		q->head = p;
111	}
112	q->depth++;
113	spin_unlock_irqrestore(&q->lock, flags);
114}
115
116static inline int smtc_ipi_qdepth(struct smtc_ipi_q *q)
117{
118	unsigned long flags;
119	int retval;
120
121	spin_lock_irqsave(&q->lock, flags);
122	retval = q->depth;
123	spin_unlock_irqrestore(&q->lock, flags);
124	return retval;
125}
126
127extern void smtc_send_ipi(int cpu, int type, unsigned int action);
128
129#endif /* __ASM_SMTC_IPI_H */