arch/powerpc/include/asm/mpic_msgr.h

   1 /*
   2  * Copyright 2011-2012, Meador Inge, Mentor Graphics Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; version 2 of the
   7  * License.
   8  *
   9  */
  10
  11 #ifndef _ASM_MPIC_MSGR_H
  12 #define _ASM_MPIC_MSGR_H
  13
  14 #include <linux/types.h>
  15 #include <linux/spinlock.h>
  16 #include <asm/smp.h>
  17 #include <asm/io.h>
  18
  19 struct mpic_msgr {
  20         u32 __iomem *base;
  21         u32 __iomem *mer;
  22         int irq;
  23         unsigned char in_use;
  24         raw_spinlock_t lock;
  25         int num;
  26 };
  27
  28 /* Get a message register
  29  *
  30  * @reg_num:    the MPIC message register to get
  31  *
  32  * A pointer to the message register is returned.  If
  33  * the message register asked for is already in use, then
  34  * EBUSY is returned.  If the number given is not associated
  35  * with an actual message register, then ENODEV is returned.
  36  * Successfully getting the register marks it as in use.
  37  */
  38 extern struct mpic_msgr *mpic_msgr_get(unsigned int reg_num);
  39
  40 /* Relinquish a message register
  41  *
  42  * @msgr:       the message register to return
  43  *
  44  * Disables the given message register and marks it as free.
  45  * After this call has completed successully the message
  46  * register is available to be acquired by a call to
  47  * mpic_msgr_get.
  48  */
  49 extern void mpic_msgr_put(struct mpic_msgr *msgr);
  50
  51 /* Enable a message register
  52  *
  53  * @msgr:       the message register to enable
  54  *
  55  * The given message register is enabled for sending
  56  * messages.
  57  */
  58 extern void mpic_msgr_enable(struct mpic_msgr *msgr);
  59
  60 /* Disable a message register
  61  *
  62  * @msgr:       the message register to disable
  63  *
  64  * The given message register is disabled for sending
  65  * messages.
  66  */
  67 extern void mpic_msgr_disable(struct mpic_msgr *msgr);
  68
  69 /* Write a message to a message register
  70  *
  71  * @msgr:       the message register to write to
  72  * @message:    the message to write
  73  *
  74  * The given 32-bit message is written to the given message
  75  * register.  Writing to an enabled message registers fires
  76  * an interrupt.
  77  */
  78 static inline void mpic_msgr_write(struct mpic_msgr *msgr, u32 message)
  79 {
  80         out_be32(msgr->base, message);
  81 }
  82
  83 /* Read a message from a message register
  84  *
  85  * @msgr:       the message register to read from
  86  *
  87  * Returns the 32-bit value currently in the given message register.
  88  * Upon reading the register any interrupts for that register are
  89  * cleared.
  90  */
  91 static inline u32 mpic_msgr_read(struct mpic_msgr *msgr)
  92 {
  93         return in_be32(msgr->base);
  94 }
  95
  96 /* Clear a message register
  97  *
  98  * @msgr:       the message register to clear
  99  *
 100  * Clears any interrupts associated with the given message register.
 101  */
 102 static inline void mpic_msgr_clear(struct mpic_msgr *msgr)
 103 {
 104         (void) mpic_msgr_read(msgr);
 105 }
 106
 107 /* Set the destination CPU for the message register
 108  *
 109  * @msgr:       the message register whose destination is to be set
 110  * @cpu_num:    the Linux CPU number to bind the message register to
 111  *
 112  * Note that the CPU number given is the CPU number used by the kernel
 113  * and *not* the actual hardware CPU number.
 114  */
 115 static inline void mpic_msgr_set_destination(struct mpic_msgr *msgr,
 116                                              u32 cpu_num)
 117 {
 118         out_be32(msgr->base, 1 << get_hard_smp_processor_id(cpu_num));
 119 }
 120
 121 /* Get the IRQ number for the message register
 122  * @msgr:       the message register whose IRQ is to be returned
 123  *
 124  * Returns the IRQ number associated with the given message register.
 125  * NO_IRQ is returned if this message register is not capable of
 126  * receiving interrupts.  What message register can and cannot receive
 127  * interrupts is specified in the device tree for the system.
 128  */
 129 static inline int mpic_msgr_get_irq(struct mpic_msgr *msgr)
 130 {
 131         return msgr->irq;
 132 }
 133
 134 #endif