xp.h

linux-2.6.15.6

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2004-2005 Silicon Graphics, Inc. All rights reserved.
 */


/*
 * External Cross Partition (XP) structures and defines.
 */


#ifndef _ASM_IA64_SN_XP_H
#define _ASM_IA64_SN_XP_H


#include <linux/cache.h>
#include <linux/hardirq.h>
#include <asm/sn/types.h>
#include <asm/sn/bte.h>


#ifdef USE_DBUG_ON
#define DBUG_ON(condition)	BUG_ON(condition)
#else
#define DBUG_ON(condition)
#endif


/*
 * Define the maximum number of logically defined partitions the system
 * can support. It is constrained by the maximum number of hardware
 * partitionable regions. The term 'region' in this context refers to the
 * minimum number of nodes that can comprise an access protection grouping.
 * The access protection is in regards to memory, IPI and IOI.
 *
 * The maximum number of hardware partitionable regions is equal to the
 * maximum number of nodes in the entire system divided by the minimum number
 * of nodes that comprise an access protection grouping.
 */
#define XP_MAX_PARTITIONS	64


/*
 * Define the number of u64s required to represent all the C-brick nasids
 * as a bitmap.  The cross-partition kernel modules deal only with
 * C-brick nasids, thus the need for bitmaps which don't account for
 * odd-numbered (non C-brick) nasids.
 */
#define XP_MAX_PHYSNODE_ID	(MAX_NUMALINK_NODES / 2)
#define XP_NASID_MASK_BYTES	((XP_MAX_PHYSNODE_ID + 7) / 8)
#define XP_NASID_MASK_WORDS	((XP_MAX_PHYSNODE_ID + 63) / 64)


/*
 * Wrapper for bte_copy() that should it return a failure status will retry
 * the bte_copy() once in the hope that the failure was due to a temporary
 * aberration (i.e., the link going down temporarily).
 *
 * See bte_copy for definition of the input parameters.
 *
 * Note: xp_bte_copy() should never be called while holding a spinlock.
 */
static inline bte_result_t
xp_bte_copy(u64 src, u64 dest, u64 len, u64 mode, void *notification)
{
	bte_result_t ret;


	ret = bte_copy(src, dest, len, mode, notification);

	if (ret != BTE_SUCCESS) {
		if (!in_interrupt()) {
			cond_resched();
		}
		ret = bte_copy(src, dest, len, mode, notification);
	}

	return ret;
}


/*
 * XPC establishes channel connections between the local partition and any
 * other partition that is currently up. Over these channels, kernel-level
 * `users' can communicate with their counterparts on the other partitions.
 *
 * The maxinum number of channels is limited to eight. For performance reasons,
 * the internal cross partition structures require sixteen bytes per channel,
 * and eight allows all of this interface-shared info to fit in one cache line.
 *
 * XPC_NCHANNELS reflects the total number of channels currently defined.
 * If the need for additional channels arises, one can simply increase
 * XPC_NCHANNELS accordingly. If the day should come where that number
 * exceeds the MAXIMUM number of channels allowed (eight), then one will need
 * to make changes to the XPC code to allow for this.
 */
#define XPC_MEM_CHANNEL		0	/* memory channel number */
#define	XPC_NET_CHANNEL		1	/* network channel number */

#define	XPC_NCHANNELS		2	/* #of defined channels */
#define XPC_MAX_NCHANNELS	8	/* max #of channels allowed */

#if XPC_NCHANNELS > XPC_MAX_NCHANNELS
#error	XPC_NCHANNELS exceeds MAXIMUM allowed.
#endif


/*
 * The format of an XPC message is as follows:
 *
 *      +-------+--------------------------------+
 *      | flags |////////////////////////////////|
 *      +-------+--------------------------------+
 *      |             message #                  |
 *      +----------------------------------------+
 *      |     payload (user-defined message)     |
 *      |                                        |
 *         		:
 *      |                                        |
 *      +----------------------------------------+
 *
 * The size of the payload is defined by the user via xpc_connect(). A user-
 * defined message resides in the payload area.
 *
 * The user should have no dealings with the message header, but only the
 * message's payload. When a message entry is allocated (via xpc_allocate())
 * a pointer to the payload area is returned and not the actual beginning of
 * the XPC message. The user then constructs a message in the payload area
 * and passes that pointer as an argument on xpc_send() or xpc_send_notify().
 *
 * The size of a message entry (within a message queue) must be a cacheline
 * sized multiple in order to facilitate the BTE transfer of messages from one
 * message queue to another. A macro, XPC_MSG_SIZE(), is provided for the user
 * that wants to fit as many msg entries as possible in a given memory size
 * (e.g. a memory page).
 */
struct xpc_msg {
	u8 flags;		/* FOR XPC INTERNAL USE ONLY */
	u8 reserved[7];		/* FOR XPC INTERNAL USE ONLY */
	s64 number;		/* FOR XPC INTERNAL USE ONLY */

	u64 payload;		/* user defined portion of message */
};


#define XPC_MSG_PAYLOAD_OFFSET	(u64) (&((struct xpc_msg *)0)->payload)
#define XPC_MSG_SIZE(_payload_size) \
		L1_CACHE_ALIGN(XPC_MSG_PAYLOAD_OFFSET + (_payload_size))


/*
 * Define the return values and values passed to user's callout functions.
 * (It is important to add new value codes at the end just preceding
 * xpcUnknownReason, which must have the highest numerical value.)
 */
enum xpc_retval {
	xpcSuccess = 0,

	xpcNotConnected,	/*  1: channel is not connected */
	xpcConnected,		/*  2: channel connected (opened) */
	xpcRETIRED1,		/*  3: (formerly xpcDisconnected) */

	xpcMsgReceived,		/*  4: message received */
	xpcMsgDelivered,	/*  5: message delivered and acknowledged */

	xpcRETIRED2,		/*  6: (formerly xpcTransferFailed) */

	xpcNoWait,		/*  7: operation would require wait */
	xpcRetry,		/*  8: retry operation */
	xpcTimeout,		/*  9: timeout in xpc_allocate_msg_wait() */
	xpcInterrupted,		/* 10: interrupted wait */

	xpcUnequalMsgSizes,	/* 11: message size disparity between sides */
	xpcInvalidAddress,	/* 12: invalid address */

	xpcNoMemory,		/* 13: no memory available for XPC structures */
	xpcLackOfResources,	/* 14: insufficient resources for operation */
	xpcUnregistered,	/* 15: channel is not registered */
	xpcAlreadyRegistered,	/* 16: channel is already registered */

	xpcPartitionDown,	/* 17: remote partition is down */
	xpcNotLoaded,		/* 18: XPC module is not loaded */
	xpcUnloading,		/* 19: this side is unloading XPC module */

	xpcBadMagic,		/* 20: XPC MAGIC string not found */

	xpcReactivating,	/* 21: remote partition was reactivated */

	xpcUnregistering,	/* 22: this side is unregistering channel */
	xpcOtherUnregistering,	/* 23: other side is unregistering channel */

	xpcCloneKThread,	/* 24: cloning kernel thread */
	xpcCloneKThreadFailed,	/* 25: cloning kernel thread failed */

	xpcNoHeartbeat,		/* 26: remote partition has no heartbeat */

	xpcPioReadError,	/* 27: PIO read error */
	xpcPhysAddrRegFailed,	/* 28: registration of phys addr range failed */

	xpcBteDirectoryError,	/* 29: maps to BTEFAIL_DIR */
	xpcBtePoisonError,	/* 30: maps to BTEFAIL_POISON */
	xpcBteWriteError,	/* 31: maps to BTEFAIL_WERR */
	xpcBteAccessError,	/* 32: maps to BTEFAIL_ACCESS */
	xpcBtePWriteError,	/* 33: maps to BTEFAIL_PWERR */
	xpcBtePReadError,	/* 34: maps to BTEFAIL_PRERR */
	xpcBteTimeOutError,	/* 35: maps to BTEFAIL_TOUT */
	xpcBteXtalkError,	/* 36: maps to BTEFAIL_XTERR */
	xpcBteNotAvailable,	/* 37: maps to BTEFAIL_NOTAVAIL */
	xpcBteUnmappedError,	/* 38: unmapped BTEFAIL_ error */

	xpcBadVersion,		/* 39: bad version number */
	xpcVarsNotSet,		/* 40: the XPC variables are not set up */
	xpcNoRsvdPageAddr,	/* 41: unable to get rsvd page's phys addr */
	xpcInvalidPartid,	/* 42: invalid partition ID */
	xpcLocalPartid,		/* 43: local partition ID */

	xpcOtherGoingDown,	/* 44: other side going down, reason unknown */
	xpcSystemGoingDown,	/* 45: system is going down, reason unknown */
	xpcSystemHalt,		/* 46: system is being halted */
	xpcSystemReboot,	/* 47: system is being rebooted */