include/asm-mips/smtc_ipi.h

   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
  20 struct 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
  43 struct smtc_ipi_q {
  44         struct smtc_ipi *head;
  45         spinlock_t lock;
  46         struct smtc_ipi *tail;
  47         int depth;
  48 };
  49
  50 static inline void smtc_ipi_nq(struct smtc_ipi_q *q, struct smtc_ipi *p)
  51 {
  52         unsigned long flags;
  53
  54         spin_lock_irqsave(&q->lock, flags);
  55         if (q->head == NULL)
  56                 q->head = q->tail = p;
  57         else
  58                 q->tail->flink = p;
  59         p->flink = NULL;
  60         q->tail = p;
  61         q->depth++;
  62 #ifdef  SMTC_IPI_DEBUG
  63         p->sender = read_c0_tcbind();
  64         p->stamp = read_c0_count();
  65 #endif /* SMTC_IPI_DEBUG */
  66         spin_unlock_irqrestore(&q->lock, flags);
  67 }
  68
  69 static inline struct smtc_ipi *__smtc_ipi_dq(struct smtc_ipi_q *q)
  70 {
  71         struct smtc_ipi *p;
  72
  73         if (q->head == NULL)
  74                 p = NULL;
  75         else {
  76                 p = q->head;
  77                 q->head = q->head->flink;
  78                 q->depth--;
  79                 /* Arguably unnecessary, but leaves queue cleaner */
  80                 if (q->head == NULL)
  81                         q->tail = NULL;
  82         }
  83
  84         return p;
  85 }
  86
  87 static inline struct smtc_ipi *smtc_ipi_dq(struct smtc_ipi_q *q)
  88 {
  89         unsigned long flags;
  90         struct smtc_ipi *p;
  91
  92         spin_lock_irqsave(&q->lock, flags);
  93         p = __smtc_ipi_dq(q);
  94         spin_unlock_irqrestore(&q->lock, flags);
  95
  96         return p;
  97 }
  98
  99 static inline void smtc_ipi_req(struct smtc_ipi_q *q, struct smtc_ipi *p)
 100 {
 101         unsigned long flags;
 102
 103         spin_lock_irqsave(&q->lock, flags);
 104         if (q->head == NULL) {
 105                 q->head = q->tail = p;
 106                 p->flink = NULL;
 107         } else {
 108                 p->flink = q->head;
 109                 q->head = p;
 110         }
 111         q->depth++;
 112         spin_unlock_irqrestore(&q->lock, flags);
 113 }
 114
 115 static inline int smtc_ipi_qdepth(struct smtc_ipi_q *q)
 116 {
 117         unsigned long flags;
 118         int retval;
 119
 120         spin_lock_irqsave(&q->lock, flags);
 121         retval = q->depth;
 122         spin_unlock_irqrestore(&q->lock, flags);
 123         return retval;
 124 }
 125
 126 extern void smtc_send_ipi(int cpu, int type, unsigned int action);
 127
 128 #endif /* __ASM_SMTC_IPI_H */