release/src-rt-6.x.4708/linux/linux-2.6.36/arch/powerpc/include/asm/iseries/it_lp_queue.h

   1 /*
   2  * Copyright (C) 2001  Mike Corrigan IBM Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  17  */
  18 #ifndef _ASM_POWERPC_ISERIES_IT_LP_QUEUE_H
  19 #define _ASM_POWERPC_ISERIES_IT_LP_QUEUE_H
  20
  21 /*
  22  *      This control block defines the simple LP queue structure that is
  23  *      shared between the hypervisor (PLIC) and the OS in order to send
  24  *      events to an LP.
  25  */
  26
  27 #include <asm/types.h>
  28 #include <asm/ptrace.h>
  29
  30 #define IT_LP_MAX_QUEUES        8
  31
  32 #define IT_LP_NOT_USED          0       /* Queue will not be used by PLIC */
  33 #define IT_LP_DEDICATED_IO      1       /* Queue dedicated to IO processor specified */
  34 #define IT_LP_DEDICATED_LP      2       /* Queue dedicated to LP specified */
  35 #define IT_LP_SHARED            3       /* Queue shared for both IO and LP */
  36
  37 #define IT_LP_EVENT_STACK_SIZE  4096
  38 #define IT_LP_EVENT_MAX_SIZE    256
  39 #define IT_LP_EVENT_ALIGN       64
  40
  41 struct hvlpevent_queue {
  42 /*
  43  * The hq_current_event is the pointer to the next event stack entry
  44  * that will become valid.  The OS must peek at this entry to determine
  45  * if it is valid.  PLIC will set the valid indicator as the very last
  46  * store into that entry.
  47  *
  48  * When the OS has completed processing of the event then it will mark
  49  * the event as invalid so that PLIC knows it can store into that event
  50  * location again.
  51  *
  52  * If the event stack fills and there are overflow events, then PLIC
  53  * will set the hq_overflow_pending flag in which case the OS will
  54  * have to fetch the additional LP events once they have drained the
  55  * event stack.
  56  *
  57  * The first 16-bytes are known by both the OS and PLIC.  The remainder
  58  * of the cache line is for use by the OS.
  59  */
  60         u8              hq_overflow_pending;    /* 0x00 Overflow events are pending */
  61         u8              hq_status;              /* 0x01 DedicatedIo or DedicatedLp or NotUsed */
  62         u16             hq_proc_index;          /* 0x02 Logical Proc Index for correlation */
  63         u8              hq_reserved1[12];       /* 0x04 */
  64         char            *hq_current_event;      /* 0x10 */
  65         char            *hq_last_event;         /* 0x18 */
  66         char            *hq_event_stack;        /* 0x20 */
  67         u8              hq_index;               /* 0x28 unique sequential index. */
  68         u8              hq_reserved2[3];        /* 0x29-2b */
  69         spinlock_t      hq_lock;
  70 };
  71
  72 extern struct hvlpevent_queue hvlpevent_queue;
  73
  74 extern int hvlpevent_is_pending(void);
  75 extern void process_hvlpevents(void);
  76 extern void setup_hvlpevent_queue(void);
  77
  78 #endif /* _ASM_POWERPC_ISERIES_IT_LP_QUEUE_H */