[IA64-SGI] SGI Altix cross partition functionality (2nd
This patch contains the shim module (XP) which interfaces between the
communication module (XPC) and the functional support modules (like XPNET).
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index cad8346..ce13ad6 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -217,6 +217,16 @@
If you are compiling a kernel that will run under SGI's IA-64
simulator (Medusa) then say Y, otherwise say N.
+config IA64_SGI_SN_XP
+ tristate "Support communication between SGI SSIs"
+ depends on MSPEC
+ help
+ An SGI machine can be divided into multiple Single System
+ Images which act independently of each other and have
+ hardware based memory protection from the others. Enabling
+ this feature will allow for direct communication between SSIs
+ based on a network adapter and DMA messaging.
+
config FORCE_MAX_ZONEORDER
int
default "18"
diff --git a/arch/ia64/sn/kernel/xp_main.c b/arch/ia64/sn/kernel/xp_main.c
new file mode 100644
index 0000000..3be52a3
--- /dev/null
+++ b/arch/ia64/sn/kernel/xp_main.c
@@ -0,0 +1,289 @@
+/*
+ * 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.
+ */
+
+
+/*
+ * Cross Partition (XP) base.
+ *
+ * XP provides a base from which its users can interact
+ * with XPC, yet not be dependent on XPC.
+ *
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <asm/sn/intr.h>
+#include <asm/sn/sn_sal.h>
+#include <asm/sn/xp.h>
+
+
+/*
+ * Target of nofault PIO read.
+ */
+u64 xp_nofault_PIOR_target;
+
+
+/*
+ * xpc_registrations[] keeps track of xpc_connect()'s done by the kernel-level
+ * users of XPC.
+ */
+struct xpc_registration xpc_registrations[XPC_NCHANNELS];
+
+
+/*
+ * Initialize the XPC interface to indicate that XPC isn't loaded.
+ */
+static enum xpc_retval xpc_notloaded(void) { return xpcNotLoaded; }
+
+struct xpc_interface xpc_interface = {
+ (void (*)(int)) xpc_notloaded,
+ (void (*)(int)) xpc_notloaded,
+ (enum xpc_retval (*)(partid_t, int, u32, void **)) xpc_notloaded,
+ (enum xpc_retval (*)(partid_t, int, void *)) xpc_notloaded,
+ (enum xpc_retval (*)(partid_t, int, void *, xpc_notify_func, void *))
+ xpc_notloaded,
+ (void (*)(partid_t, int, void *)) xpc_notloaded,
+ (enum xpc_retval (*)(partid_t, void *)) xpc_notloaded
+};
+
+
+/*
+ * XPC calls this when it (the XPC module) has been loaded.
+ */
+void
+xpc_set_interface(void (*connect)(int),
+ void (*disconnect)(int),
+ enum xpc_retval (*allocate)(partid_t, int, u32, void **),
+ enum xpc_retval (*send)(partid_t, int, void *),
+ enum xpc_retval (*send_notify)(partid_t, int, void *,
+ xpc_notify_func, void *),
+ void (*received)(partid_t, int, void *),
+ enum xpc_retval (*partid_to_nasids)(partid_t, void *))
+{
+ xpc_interface.connect = connect;
+ xpc_interface.disconnect = disconnect;
+ xpc_interface.allocate = allocate;
+ xpc_interface.send = send;
+ xpc_interface.send_notify = send_notify;
+ xpc_interface.received = received;
+ xpc_interface.partid_to_nasids = partid_to_nasids;
+}
+
+
+/*
+ * XPC calls this when it (the XPC module) is being unloaded.
+ */
+void
+xpc_clear_interface(void)
+{
+ xpc_interface.connect = (void (*)(int)) xpc_notloaded;
+ xpc_interface.disconnect = (void (*)(int)) xpc_notloaded;
+ xpc_interface.allocate = (enum xpc_retval (*)(partid_t, int, u32,
+ void **)) xpc_notloaded;
+ xpc_interface.send = (enum xpc_retval (*)(partid_t, int, void *))
+ xpc_notloaded;
+ xpc_interface.send_notify = (enum xpc_retval (*)(partid_t, int, void *,
+ xpc_notify_func, void *)) xpc_notloaded;
+ xpc_interface.received = (void (*)(partid_t, int, void *))
+ xpc_notloaded;
+ xpc_interface.partid_to_nasids = (enum xpc_retval (*)(partid_t, void *))
+ xpc_notloaded;
+}
+
+
+/*
+ * Register for automatic establishment of a channel connection whenever
+ * a partition comes up.
+ *
+ * Arguments:
+ *
+ * ch_number - channel # to register for connection.
+ * func - function to call for asynchronous notification of channel
+ * state changes (i.e., connection, disconnection, error) and
+ * the arrival of incoming messages.
+ * key - pointer to optional user-defined value that gets passed back
+ * to the user on any callouts made to func.
+ * payload_size - size in bytes of the XPC message's payload area which
+ * contains a user-defined message. The user should make
+ * this large enough to hold their largest message.
+ * nentries - max #of XPC message entries a message queue can contain.
+ * The actual number, which is determined when a connection
+ * is established and may be less then requested, will be
+ * passed to the user via the xpcConnected callout.
+ * assigned_limit - max number of kthreads allowed to be processing
+ * messages (per connection) at any given instant.
+ * idle_limit - max number of kthreads allowed to be idle at any given
+ * instant.
+ */
+enum xpc_retval
+xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
+ u16 nentries, u32 assigned_limit, u32 idle_limit)
+{
+ struct xpc_registration *registration;
+
+
+ DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
+ DBUG_ON(payload_size == 0 || nentries == 0);
+ DBUG_ON(func == NULL);
+ DBUG_ON(assigned_limit == 0 || idle_limit > assigned_limit);
+
+ registration = &xpc_registrations[ch_number];
+
+ if (down_interruptible(®istration->sema) != 0) {
+ return xpcInterrupted;
+ }
+
+ /* if XPC_CHANNEL_REGISTERED(ch_number) */
+ if (registration->func != NULL) {
+ up(®istration->sema);
+ return xpcAlreadyRegistered;
+ }
+
+ /* register the channel for connection */
+ registration->msg_size = XPC_MSG_SIZE(payload_size);
+ registration->nentries = nentries;
+ registration->assigned_limit = assigned_limit;
+ registration->idle_limit = idle_limit;
+ registration->key = key;
+ registration->func = func;
+
+ up(®istration->sema);
+
+ xpc_interface.connect(ch_number);
+
+ return xpcSuccess;
+}
+
+
+/*
+ * Remove the registration for automatic connection of the specified channel
+ * when a partition comes up.
+ *
+ * Before returning this xpc_disconnect() will wait for all connections on the
+ * specified channel have been closed/torndown. So the caller can be assured
+ * that they will not be receiving any more callouts from XPC to their
+ * function registered via xpc_connect().
+ *
+ * Arguments:
+ *
+ * ch_number - channel # to unregister.
+ */
+void
+xpc_disconnect(int ch_number)
+{
+ struct xpc_registration *registration;
+
+
+ DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
+
+ registration = &xpc_registrations[ch_number];
+
+ /*
+ * We've decided not to make this a down_interruptible(), since we
+ * figured XPC's users will just turn around and call xpc_disconnect()
+ * again anyways, so we might as well wait, if need be.
+ */
+ down(®istration->sema);
+
+ /* if !XPC_CHANNEL_REGISTERED(ch_number) */
+ if (registration->func == NULL) {
+ up(®istration->sema);
+ return;
+ }
+
+ /* remove the connection registration for the specified channel */
+ registration->func = NULL;
+ registration->key = NULL;
+ registration->nentries = 0;
+ registration->msg_size = 0;
+ registration->assigned_limit = 0;
+ registration->idle_limit = 0;
+
+ xpc_interface.disconnect(ch_number);
+
+ up(®istration->sema);
+
+ return;
+}
+
+
+int __init
+xp_init(void)
+{
+ int ret, ch_number;
+ u64 func_addr = *(u64 *) xp_nofault_PIOR;
+ u64 err_func_addr = *(u64 *) xp_error_PIOR;
+
+
+ if (!ia64_platform_is("sn2")) {
+ return -ENODEV;
+ }
+
+ /*
+ * Register a nofault code region which performs a cross-partition
+ * PIO read. If the PIO read times out, the MCA handler will consume
+ * the error and return to a kernel-provided instruction to indicate
+ * an error. This PIO read exists because it is guaranteed to timeout
+ * if the destination is down (AMO operations do not timeout on at
+ * least some CPUs on Shubs <= v1.2, which unfortunately we have to
+ * work around).
+ */
+ if ((ret = sn_register_nofault_code(func_addr, err_func_addr,
+ err_func_addr, 1, 1)) != 0) {
+ printk(KERN_ERR "XP: can't register nofault code, error=%d\n",
+ ret);
+ }
+ /*
+ * Setup the nofault PIO read target. (There is no special reason why
+ * SH_IPI_ACCESS was selected.)
+ */
+ if (is_shub2()) {
+ xp_nofault_PIOR_target = SH2_IPI_ACCESS0;
+ } else {
+ xp_nofault_PIOR_target = SH1_IPI_ACCESS;
+ }
+
+ /* initialize the connection registration semaphores */
+ for (ch_number = 0; ch_number < XPC_NCHANNELS; ch_number++) {
+ sema_init(&xpc_registrations[ch_number].sema, 1); /* mutex */
+ }
+
+ return 0;
+}
+module_init(xp_init);
+
+
+void __exit
+xp_exit(void)
+{
+ u64 func_addr = *(u64 *) xp_nofault_PIOR;
+ u64 err_func_addr = *(u64 *) xp_error_PIOR;
+
+
+ /* unregister the PIO read nofault code region */
+ (void) sn_register_nofault_code(func_addr, err_func_addr,
+ err_func_addr, 1, 0);
+}
+module_exit(xp_exit);
+
+
+MODULE_AUTHOR("Silicon Graphics, Inc.");
+MODULE_DESCRIPTION("Cross Partition (XP) base");
+MODULE_LICENSE("GPL");
+
+EXPORT_SYMBOL(xp_nofault_PIOR);
+EXPORT_SYMBOL(xp_nofault_PIOR_target);
+EXPORT_SYMBOL(xpc_registrations);
+EXPORT_SYMBOL(xpc_interface);
+EXPORT_SYMBOL(xpc_clear_interface);
+EXPORT_SYMBOL(xpc_set_interface);
+EXPORT_SYMBOL(xpc_connect);
+EXPORT_SYMBOL(xpc_disconnect);
+
diff --git a/arch/ia64/sn/kernel/xp_nofault.S b/arch/ia64/sn/kernel/xp_nofault.S
new file mode 100644
index 0000000..b772543
--- /dev/null
+++ b/arch/ia64/sn/kernel/xp_nofault.S
@@ -0,0 +1,31 @@
+/*
+ * 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.
+ */
+
+
+/*
+ * The xp_nofault_PIOR function takes a pointer to a remote PIO register
+ * and attempts to load and consume a value from it. This function
+ * will be registered as a nofault code block. In the event that the
+ * PIO read fails, the MCA handler will force the error to look
+ * corrected and vector to the xp_error_PIOR which will return an error.
+ *
+ * extern int xp_nofault_PIOR(void *remote_register);
+ */
+
+ .global xp_nofault_PIOR
+xp_nofault_PIOR:
+ mov r8=r0 // Stage a success return value
+ ld8.acq r9=[r32];; // PIO Read the specified register
+ adds r9=1,r9 // Add to force a consume
+ br.ret.sptk.many b0;; // Return success
+
+ .global xp_error_PIOR
+xp_error_PIOR:
+ mov r8=1 // Return value of 1
+ br.ret.sptk.many b0;; // Return failure
+
diff --git a/include/asm-ia64/sn/xp.h b/include/asm-ia64/sn/xp.h
new file mode 100644
index 0000000..9902185
--- /dev/null
+++ b/include/asm-ia64/sn/xp.h
@@ -0,0 +1,436 @@
+/*
+ * 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/version.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_PHYSNODE_ID / 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 */
+
+ xpcUnknownReason /* 44: unknown reason -- must be last in list */
+};
+
+
+/*
+ * Define the callout function types used by XPC to update the user on
+ * connection activity and state changes (via the user function registered by
+ * xpc_connect()) and to notify them of messages received and delivered (via
+ * the user function registered by xpc_send_notify()).
+ *
+ * The two function types are xpc_channel_func and xpc_notify_func and
+ * both share the following arguments, with the exception of "data", which
+ * only xpc_channel_func has.
+ *
+ * Arguments:
+ *
+ * reason - reason code. (See following table.)
+ * partid - partition ID associated with condition.
+ * ch_number - channel # associated with condition.
+ * data - pointer to optional data. (See following table.)
+ * key - pointer to optional user-defined value provided as the "key"
+ * argument to xpc_connect() or xpc_send_notify().
+ *
+ * In the following table the "Optional Data" column applies to callouts made
+ * to functions registered by xpc_connect(). A "NA" in that column indicates
+ * that this reason code can be passed to functions registered by
+ * xpc_send_notify() (i.e. they don't have data arguments).
+ *
+ * Also, the first three reason codes in the following table indicate
+ * success, whereas the others indicate failure. When a failure reason code
+ * is received, one can assume that the channel is not connected.
+ *
+ *
+ * Reason Code | Cause | Optional Data
+ * =====================+================================+=====================
+ * xpcConnected | connection has been established| max #of entries
+ * | to the specified partition on | allowed in message
+ * | the specified channel | queue
+ * ---------------------+--------------------------------+---------------------
+ * xpcMsgReceived | an XPC message arrived from | address of payload
+ * | the specified partition on the |
+ * | specified channel | [the user must call
+ * | | xpc_received() when
+ * | | finished with the
+ * | | payload]
+ * ---------------------+--------------------------------+---------------------
+ * xpcMsgDelivered | notification that the message | NA
+ * | was delivered to the intended |
+ * | recipient and that they have |
+ * | acknowledged its receipt by |
+ * | calling xpc_received() |
+ * =====================+================================+=====================
+ * xpcUnequalMsgSizes | can't connect to the specified | NULL
+ * | partition on the specified |
+ * | channel because of mismatched |
+ * | message sizes |
+ * ---------------------+--------------------------------+---------------------
+ * xpcNoMemory | insufficient memory avaiable | NULL
+ * | to allocate message queue |
+ * ---------------------+--------------------------------+---------------------
+ * xpcLackOfResources | lack of resources to create | NULL
+ * | the necessary kthreads to |
+ * | support the channel |
+ * ---------------------+--------------------------------+---------------------
+ * xpcUnregistering | this side's user has | NULL or NA
+ * | unregistered by calling |
+ * | xpc_disconnect() |
+ * ---------------------+--------------------------------+---------------------
+ * xpcOtherUnregistering| the other side's user has | NULL or NA
+ * | unregistered by calling |
+ * | xpc_disconnect() |
+ * ---------------------+--------------------------------+---------------------
+ * xpcNoHeartbeat | the other side's XPC is no | NULL or NA
+ * | longer heartbeating |
+ * | |
+ * ---------------------+--------------------------------+---------------------
+ * xpcUnloading | this side's XPC module is | NULL or NA
+ * | being unloaded |
+ * | |
+ * ---------------------+--------------------------------+---------------------
+ * xpcOtherUnloading | the other side's XPC module is | NULL or NA
+ * | is being unloaded |
+ * | |
+ * ---------------------+--------------------------------+---------------------
+ * xpcPioReadError | xp_nofault_PIOR() returned an | NULL or NA
+ * | error while sending an IPI |
+ * | |
+ * ---------------------+--------------------------------+---------------------
+ * xpcInvalidAddress | the address either received or | NULL or NA
+ * | sent by the specified partition|
+ * | is invalid |
+ * ---------------------+--------------------------------+---------------------
+ * xpcBteNotAvailable | attempt to pull data from the | NULL or NA
+ * xpcBtePoisonError | specified partition over the |
+ * xpcBteWriteError | specified channel via a |
+ * xpcBteAccessError | bte_copy() failed |
+ * xpcBteTimeOutError | |
+ * xpcBteXtalkError | |
+ * xpcBteDirectoryError | |
+ * xpcBteGenericError | |
+ * xpcBteUnmappedError | |
+ * ---------------------+--------------------------------+---------------------
+ * xpcUnknownReason | the specified channel to the | NULL or NA
+ * | specified partition was |
+ * | unavailable for unknown reasons|
+ * =====================+================================+=====================
+ */
+
+typedef void (*xpc_channel_func)(enum xpc_retval reason, partid_t partid,
+ int ch_number, void *data, void *key);
+
+typedef void (*xpc_notify_func)(enum xpc_retval reason, partid_t partid,
+ int ch_number, void *key);
+
+
+/*
+ * The following is a registration entry. There is a global array of these,
+ * one per channel. It is used to record the connection registration made
+ * by the users of XPC. As long as a registration entry exists, for any
+ * partition that comes up, XPC will attempt to establish a connection on
+ * that channel. Notification that a connection has been made will occur via
+ * the xpc_channel_func function.
+ *
+ * The 'func' field points to the function to call when aynchronous
+ * notification is required for such events as: a connection established/lost,
+ * or an incomming message received, or an error condition encountered. A
+ * non-NULL 'func' field indicates that there is an active registration for
+ * the channel.
+ */
+struct xpc_registration {
+ struct semaphore sema;
+ xpc_channel_func func; /* function to call */
+ void *key; /* pointer to user's key */
+ u16 nentries; /* #of msg entries in local msg queue */
+ u16 msg_size; /* message queue's message size */
+ u32 assigned_limit; /* limit on #of assigned kthreads */
+ u32 idle_limit; /* limit on #of idle kthreads */
+} ____cacheline_aligned;
+
+
+#define XPC_CHANNEL_REGISTERED(_c) (xpc_registrations[_c].func != NULL)
+
+
+/* the following are valid xpc_allocate() flags */
+#define XPC_WAIT 0 /* wait flag */
+#define XPC_NOWAIT 1 /* no wait flag */
+
+
+struct xpc_interface {
+ void (*connect)(int);
+ void (*disconnect)(int);
+ enum xpc_retval (*allocate)(partid_t, int, u32, void **);
+ enum xpc_retval (*send)(partid_t, int, void *);
+ enum xpc_retval (*send_notify)(partid_t, int, void *,
+ xpc_notify_func, void *);
+ void (*received)(partid_t, int, void *);
+ enum xpc_retval (*partid_to_nasids)(partid_t, void *);
+};
+
+
+extern struct xpc_interface xpc_interface;
+
+extern void xpc_set_interface(void (*)(int),
+ void (*)(int),
+ enum xpc_retval (*)(partid_t, int, u32, void **),
+ enum xpc_retval (*)(partid_t, int, void *),
+ enum xpc_retval (*)(partid_t, int, void *, xpc_notify_func,
+ void *),
+ void (*)(partid_t, int, void *),
+ enum xpc_retval (*)(partid_t, void *));
+extern void xpc_clear_interface(void);
+
+
+extern enum xpc_retval xpc_connect(int, xpc_channel_func, void *, u16,
+ u16, u32, u32);
+extern void xpc_disconnect(int);
+
+static inline enum xpc_retval
+xpc_allocate(partid_t partid, int ch_number, u32 flags, void **payload)
+{
+ return xpc_interface.allocate(partid, ch_number, flags, payload);
+}
+
+static inline enum xpc_retval
+xpc_send(partid_t partid, int ch_number, void *payload)
+{
+ return xpc_interface.send(partid, ch_number, payload);
+}
+
+static inline enum xpc_retval
+xpc_send_notify(partid_t partid, int ch_number, void *payload,
+ xpc_notify_func func, void *key)
+{
+ return xpc_interface.send_notify(partid, ch_number, payload, func, key);
+}
+
+static inline void
+xpc_received(partid_t partid, int ch_number, void *payload)
+{
+ return xpc_interface.received(partid, ch_number, payload);
+}
+
+static inline enum xpc_retval
+xpc_partid_to_nasids(partid_t partid, void *nasids)
+{
+ return xpc_interface.partid_to_nasids(partid, nasids);
+}
+
+
+extern u64 xp_nofault_PIOR_target;
+extern int xp_nofault_PIOR(void *);
+extern int xp_error_PIOR(void);
+
+
+#endif /* _ASM_IA64_SN_XP_H */
+