path: root/drivers/misc/sgi-xp/xpc.h

/*
 * 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) 2004-2009 Silicon Graphics, Inc.  All Rights Reserved.
 */

/*
 * Cross Partition Communication (XPC) structures and macros.
 */

#ifndef _DRIVERS_MISC_SGIXP_XPC_H
#define _DRIVERS_MISC_SGIXP_XPC_H

#include <linux/wait.h>
#include <linux/completion.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include "xp.h"

/*
 * XPC Version numbers consist of a major and minor number. XPC can always
 * talk to versions with same major #, and never talk to versions with a
 * different major #.
 */
#define _XPC_VERSION(_maj, _min)	(((_maj) << 4) | ((_min) & 0xf))
#define XPC_VERSION_MAJOR(_v)		((_v) >> 4)
#define XPC_VERSION_MINOR(_v)		((_v) & 0xf)

/* define frequency of the heartbeat and frequency how often it's checked */
#define XPC_HB_DEFAULT_INTERVAL		5	/* incr HB every x secs */
#define XPC_HB_CHECK_DEFAULT_INTERVAL	20	/* check HB every x secs */

/* define the process name of HB checker and the CPU it is pinned to */
#define XPC_HB_CHECK_THREAD_NAME	"xpc_hb"
#define XPC_HB_CHECK_CPU		0

/* define the process name of the discovery thread */
#define XPC_DISCOVERY_THREAD_NAME	"xpc_discovery"

/*
 * the reserved page
 *
 *   SAL reserves one page of memory per partition for XPC. Though a full page
 *   in length (16384 bytes), its starting address is not page aligned, but it
 *   is cacheline aligned. The reserved page consists of the following:
 *
 *   reserved page header
 *
 *     The first two 64-byte cachelines of the reserved page contain the
 *     header (struct xpc_rsvd_page). Before SAL initialization has completed,
 *     SAL has set up the following fields of the reserved page header:
 *     SAL_signature, SAL_version, SAL_partid, and SAL_nasids_size. The
 *     other fields are set up by XPC. (xpc_rsvd_page points to the local
 *     partition's reserved page.)
 *
 *   part_nasids mask
 *   mach_nasids mask
 *
 *     SAL also sets up two bitmaps (or masks), one that reflects the actual
 *     nasids in this partition (part_nasids), and the other that reflects
 *     the actual nasids in the entire machine (mach_nasids). We're only
 *     interested in the even numbered nasids (which contain the processors
 *     and/or memory), so we only need half as many bits to represent the
 *     nasids. When mapping nasid to bit in a mask (or bit to nasid) be sure
 *     to either divide or multiply by 2. The part_nasids mask is located
 *     starting at the first cacheline following the reserved page header. The
 *     mach_nasids mask follows right after the part_nasids mask. The size in
 *     bytes of each mask is reflected by the reserved page header field
 *     'SAL_nasids_size'. (Local partition's mask pointers are xpc_part_nasids
 *     and xpc_mach_nasids.)
 *
 *     Immediately following the mach_nasids mask are the XPC variables
 *     required by other partitions. First are those that are generic to all
 *     partitions (vars), followed on the next available cacheline by those
 *     which are partition specific (vars part). These are setup by XPC.
 *
 * Note: Until 'ts_jiffies' is set non-zero, the partition XPC code has not been
 *       initialized.
 */
struct xpc_rsvd_page {
	u64 SAL_signature;	/* SAL: unique signature */
	u64 SAL_version;	/* SAL: version */
	short SAL_partid;	/* SAL: partition ID */
	short max_npartitions;	/* value of XPC_MAX_PARTITIONS */
	u8 version;
	u8 pad1[3];		/* align to next u64 in 1st 64-byte cacheline */
	unsigned long ts_jiffies; /* timestamp when rsvd pg was setup by XPC */
	union {
		struct {
			unsigned long heartbeat_gpa; /* phys addr */
			unsigned long activate_gru_mq_desc_gpa; /* phys addr */
		} uv;
	} sn;
	u64 pad2[9];		/* align to last u64 in 2nd 64-byte cacheline */
	u64 SAL_nasids_size;	/* SAL: size of each nasid mask in bytes */
};

#define XPC_RP_VERSION _XPC_VERSION(3, 0) /* version 3.0 of the reserved page */

/* the reserved page sizes and offsets */

#define XPC_RP_HEADER_SIZE	L1_CACHE_ALIGN(sizeof(struct xpc_rsvd_page))

#define XPC_RP_PART_NASIDS(_rp) ((unsigned long *)((u8 *)(_rp) + \
				 XPC_RP_HEADER_SIZE))
#define XPC_RP_MACH_NASIDS(_rp) (XPC_RP_PART_NASIDS(_rp) + \
				 xpc_nasid_mask_nlongs)


/*
 * The following structure describes the partition's heartbeat info which
 * will be periodically read by other partitions to determine whether this
 * XPC is still 'alive'.
 */
struct xpc_heartbeat_uv {
	unsigned long value;
	unsigned long offline;	/* if 0, heartbeat should be changing */
};

/*
 * Info pertinent to a GRU message queue using a watch list for irq generation.
 */
struct xpc_gru_mq_uv {
	void *address;		/* address of GRU message queue */
	unsigned int order;	/* size of GRU message queue as a power of 2 */
	int irq;		/* irq raised when message is received in mq */
	int mmr_blade;		/* blade where watchlist was allocated from */
	unsigned long mmr_offset; /* offset of irq mmr located on mmr_blade */
	unsigned long mmr_value; /* value of irq mmr located on mmr_blade */
	int watchlist_num;	/* number of watchlist allocatd by BIOS */
	void *gru_mq_desc;	/* opaque structure used by the GRU driver */
};

/*
 * The activate_mq is used to send/receive GRU messages that affect XPC's
 * partition active state and channel state. This is uv only.
 */
struct xpc_activate_mq_msghdr_uv {
	unsigned int gru_msg_hdr; /* FOR GRU INTERNAL USE ONLY */
	short partid;		/* sender's partid */
	u8 act_state;		/* sender's act_state at time msg sent */
	u8 type;		/* message's type */
	unsigned long rp_ts_jiffies; /* timestamp of sender's rp setup by XPC */
};

/* activate_mq defined message types */
#define XPC_ACTIVATE_MQ_MSG_SYNC_ACT_STATE_UV		0

#define XPC_ACTIVATE_MQ_MSG_ACTIVATE_REQ_UV		1
#define XPC_ACTIVATE_MQ_MSG_DEACTIVATE_REQ_UV		2

#define XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREQUEST_UV	3
#define XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREPLY_UV		4
#define XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREQUEST_UV	5
#define XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREPLY_UV		6
#define XPC_ACTIVATE_MQ_MSG_CHCTL_OPENCOMPLETE_UV	7

#define XPC_ACTIVATE_MQ_MSG_MARK_ENGAGED_UV		8
#define XPC_ACTIVATE_MQ_MSG_MARK_DISENGAGED_UV		9

struct xpc_activate_mq_msg_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
};

struct xpc_activate_mq_msg_activate_req_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	unsigned long rp_gpa;
	unsigned long heartbeat_gpa;
	unsigned long activate_gru_mq_desc_gpa;
};

struct xpc_activate_mq_msg_deactivate_req_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	enum xp_retval reason;
};

struct xpc_activate_mq_msg_chctl_closerequest_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	short ch_number;
	enum xp_retval reason;
};

struct xpc_activate_mq_msg_chctl_closereply_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	short ch_number;
};

struct xpc_activate_mq_msg_chctl_openrequest_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	short ch_number;
	short entry_size;	/* size of notify_mq's GRU messages */
	short local_nentries;	/* ??? Is this needed? What is? */
};

struct xpc_activate_mq_msg_chctl_openreply_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	short ch_number;
	short remote_nentries;	/* ??? Is this needed? What is? */
	short local_nentries;	/* ??? Is this needed? What is? */
	unsigned long notify_gru_mq_desc_gpa;
};

struct xpc_activate_mq_msg_chctl_opencomplete_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	short ch_number;
};

/*
 * Functions registered by add_timer() or called by kernel_thread() only
 * allow for a single 64-bit argument. The following macros can be used to
 * pack and unpack two (32-bit, 16-bit or 8-bit) arguments into or out from
 * the passed argument.
 */
#define XPC_PACK_ARGS(_arg1, _arg2) \
			((((u64)_arg1) & 0xffffffff) | \
			((((u64)_arg2) & 0xffffffff) << 32))

#define XPC_UNPACK_ARG1(_args)	(((u64)_args) & 0xffffffff)
#define XPC_UNPACK_ARG2(_args)	((((u64)_args) >> 32) & 0xffffffff)

/*
 * Define a structure that contains arguments associated with opening and
 * closing a channel.
 */
struct xpc_openclose_args {
	u16 reason;		/* reason why channel is closing */
	u16 entry_size;		/* sizeof each message entry */
	u16 remote_nentries;	/* #of message entries in remote msg queue */
	u16 local_nentries;	/* #of message entries in local msg queue */
	unsigned long local_msgqueue_pa; /* phys addr of local message queue */
};

#define XPC_OPENCLOSE_ARGS_SIZE \
	      L1_CACHE_ALIGN(sizeof(struct xpc_openclose_args) * \
	      XPC_MAX_NCHANNELS)


/*
 * Structures to define a fifo singly-linked list.
 */

struct xpc_fifo_entry_uv {
	struct xpc_fifo_entry_uv *next;
};

struct xpc_fifo_head_uv {
	struct xpc_fifo_entry_uv *first;
	struct xpc_fifo_entry_uv *last;
	spinlock_t lock;
	int n_entries;
};

/*
 * The format of a uv XPC notify_mq GRU message is as follows:
 *
 * A user-defined message resides in the payload area. The max size of the
 * payload is defined by the user via xpc_connect().
 *
 * The size of a message (payload and header) sent via the GRU must be either 1
 * or 2 GRU_CACHE_LINE_BYTES in length.
 */

struct xpc_notify_mq_msghdr_uv {
	union {
		unsigned int gru_msg_hdr;	/* FOR GRU INTERNAL USE ONLY */
		struct xpc_fifo_entry_uv next;	/* FOR XPC INTERNAL USE ONLY */
	} u;
	short partid;		/* FOR XPC INTERNAL USE ONLY */
	u8 ch_number;		/* FOR XPC INTERNAL USE ONLY */
	u8 size;		/* FOR XPC INTERNAL USE ONLY */
	unsigned int msg_slot_number;	/* FOR XPC INTERNAL USE ONLY */
};

struct xpc_notify_mq_msg_uv {
	struct xpc_notify_mq_msghdr_uv hdr;
	unsigned long payload;
};

/* struct xpc_notify_sn2 type of notification */

#define	XPC_N_CALL	0x01	/* notify function provided by user */

/*
 * Define uv's version of the notify entry. It additionally is used to allocate
 * a msg slot on the remote partition into which is copied a sent message.
 */
struct xpc_send_msg_slot_uv {
	struct xpc_fifo_entry_uv next;
	unsigned int msg_slot_number;
	xpc_notify_func func;	/* user's notify function */
	void *key;		/* pointer to user's key */
};

/*
 * Define the structure that manages all the stuff required by a channel. In
 * particular, they are used to manage the messages sent across the channel.
 *
 * This structure is private to a partition, and is NOT shared across the
 * partition boundary.
 *
 * There is an array of these structures for each remote partition. It is
 * allocated at the time a partition becomes active. The array contains one
 * of these structures for each potential channel connection to that partition.
 */

struct xpc_channel_uv {
	void *cached_notify_gru_mq_desc; /* remote partition's notify mq's */
					 /* gru mq descriptor */

	struct xpc_send_msg_slot_uv *send_msg_slots;
	void *recv_msg_slots;	/* each slot will hold a xpc_notify_mq_msg_uv */
				/* structure plus the user's payload */

	struct xpc_fifo_head_uv msg_slot_free_list;
	struct xpc_fifo_head_uv recv_msg_list;	/* deliverable payloads */
};

struct xpc_channel {
	short partid;		/* ID of remote partition connected */
	spinlock_t lock;	/* lock for updating this structure */
	unsigned int