release/src-rt-6.x.4708/linux/linux-2.6.36/arch/mips/include/asm/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         int resched_flag;       /* reschedule already queued */
  49 };
  50
  51 static 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
  70 static 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
  88 static 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
 100 static 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
 116 static 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
 127 extern void smtc_send_ipi(int cpu, int type, unsigned int action);
 128
 129 #endif /* __ASM_SMTC_IPI_H */