[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>

1 files changed, 436 insertions, 0 deletions

diff --git a/include/asm-ia64/sn/xp.h b/include/asm-ia64/sn/xp.h
new file mode 100644
index 000000000000..9902185c0288
--- /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 */
+