release/src-rt-6.x/linux/linux-2.6/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
  38 /*
  39  * A queue of IPI messages
  40  */
  41
  42 struct smtc_ipi_q {
  43         struct smtc_ipi *head;
  44         spinlock_t lock;
  45         struct smtc_ipi *tail;
  46         int depth;
  47 };
  48
  49 static inline void smtc_ipi_nq(struct smtc_ipi_q *q, struct smtc_ipi *p)
  50 {
  51         long flags;
  52
  53         spin_lock_irqsave(&q->lock, flags);
  54         if (q->head == NULL)
  55                 q->head = q->tail = p;
  56         else
  57                 q->tail->flink = p;
  58         p->flink = NULL;
  59         q->tail = p;
  60         q->depth++;
  61 #ifdef  SMTC_IPI_DEBUG
  62         p->sender = read_c0_tcbind();
  63         p->stamp = read_c0_count();
  64 #endif /* SMTC_IPI_DEBUG */
  65         spin_unlock_irqrestore(&q->lock, flags);
  66 }
  67
  68 static inline struct smtc_ipi *__smtc_ipi_dq(struct smtc_ipi_q *q)
  69 {
  70         struct smtc_ipi *p;
  71
  72         if (q->head == NULL)
  73                 p = NULL;
  74         else {
  75                 p = q->head;
  76                 q->head = q->head->flink;
  77                 q->depth--;
  78                 /* Arguably unnecessary, but leaves queue cleaner */
  79                 if (q->head == NULL)
  80                         q->tail = NULL;
  81         }
  82
  83         return p;
  84 }
  85
  86 static inline struct smtc_ipi *smtc_ipi_dq(struct smtc_ipi_q *q)
  87 {
  88         unsigned long flags;
  89         struct smtc_ipi *p;
  90
  91         spin_lock_irqsave(&q->lock, flags);
  92         p = __smtc_ipi_dq(q);
  93         spin_unlock_irqrestore(&q->lock, flags);
  94
  95         return p;
  96 }
  97
  98 static inline void smtc_ipi_req(struct smtc_ipi_q *q, struct smtc_ipi *p)
  99 {
 100         long flags;
 101
 102         spin_lock_irqsave(&q->lock, flags);
 103         if (q->head == NULL) {
 104                 q->head = q->tail = p;
 105                 p->flink = NULL;
 106         } else {
 107                 p->flink = q->head;
 108                 q->head = p;
 109         }
 110         q->depth++;
 111         spin_unlock_irqrestore(&q->lock, flags);
 112 }
 113
 114 static inline int smtc_ipi_qdepth(struct smtc_ipi_q *q)
 115 {
 116         long flags;
 117         int retval;
 118
 119         spin_lock_irqsave(&q->lock, flags);
 120         retval = q->depth;
 121         spin_unlock_irqrestore(&q->lock, flags);
 122         return retval;
 123 }
 124
 125 extern void smtc_send_ipi(int cpu, int type, unsigned int action);
 126
 127 #endif /* __ASM_SMTC_IPI_H */