[MIPS] MT: Improved multithreading support.

    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 118 insertions, 0 deletions

diff --git a/include/asm-mips/smtc_ipi.h b/include/asm-mips/smtc_ipi.h
new file mode 100644
index 0000000..f22c3e2
--- /dev/null
+++ b/include/asm-mips/smtc_ipi.h
@@ -0,0 +1,118 @@
+/*
+ * Definitions used in MIPS MT SMTC "Interprocessor Interrupt" code.
+ */
+#ifndef __ASM_SMTC_IPI_H
+#define __ASM_SMTC_IPI_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
+
+/*
+ * A queue of IPI messages
+ */
+
+struct smtc_ipi_q {
+	struct smtc_ipi *head;
+	spinlock_t lock;
+	struct smtc_ipi *tail;
+	int depth;
+};
+
+extern struct smtc_ipi_q IPIQ[NR_CPUS];
+extern struct smtc_ipi_q freeIPIq;
+
+static inline void smtc_ipi_nq(struct smtc_ipi_q *q, struct smtc_ipi *p)
+{
+	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;
+	long flags;
+
+	spin_lock_irqsave(&q->lock, flags);
+	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;
+	}
+	spin_unlock_irqrestore(&q->lock, flags);
+	return p;
+}
+
+static inline void smtc_ipi_req(struct smtc_ipi_q *q, struct smtc_ipi *p)
+{
+	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)
+{
+	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 */