xp_main.c

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/*
 * 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) 2004-2008 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/module.h>
#include <linux/device.h>
#include "xp.h"

/* define the XP debug device structures to be used with dev_dbg() et al */

struct device_driver xp_dbg_name = {
    .name = "xp"
};

struct device xp_dbg_subname = {
    .init_name = "",        /* set to "" */
    .driver = &xp_dbg_name
};

struct device *xp = &xp_dbg_subname;

/* max #of partitions possible */
short xp_max_npartitions;
EXPORT_SYMBOL_GPL(xp_max_npartitions);

short xp_partition_id;
EXPORT_SYMBOL_GPL(xp_partition_id);

u8 xp_region_size;
EXPORT_SYMBOL_GPL(xp_region_size);

unsigned long (*xp_pa) (void *addr);
EXPORT_SYMBOL_GPL(xp_pa);

unsigned long (*xp_socket_pa) (unsigned long gpa);
EXPORT_SYMBOL_GPL(xp_socket_pa);

enum xp_retval (*xp_remote_memcpy) (unsigned long dst_gpa,
                    const unsigned long src_gpa, size_t len);
EXPORT_SYMBOL_GPL(xp_remote_memcpy);

int (*xp_cpu_to_nasid) (int cpuid);
EXPORT_SYMBOL_GPL(xp_cpu_to_nasid);

enum xp_retval (*xp_expand_memprotect) (unsigned long phys_addr,
                    unsigned long size);
EXPORT_SYMBOL_GPL(xp_expand_memprotect);
enum xp_retval (*xp_restrict_memprotect) (unsigned long phys_addr,
                      unsigned long size);
EXPORT_SYMBOL_GPL(xp_restrict_memprotect);

/*
 * xpc_registrations[] keeps track of xpc_connect()'s done by the kernel-level
 * users of XPC.
 */
struct xpc_registration xpc_registrations[XPC_MAX_NCHANNELS];
EXPORT_SYMBOL_GPL(xpc_registrations);

/*
 * Initialize the XPC interface to indicate that XPC isn't loaded.
 */
static enum xp_retval
xpc_notloaded(void)
{
    return xpNotLoaded;
}

struct xpc_interface xpc_interface = {
    (void (*)(int))xpc_notloaded,
    (void (*)(int))xpc_notloaded,
    (enum xp_retval(*)(short, int, u32, void *, u16))xpc_notloaded,
    (enum xp_retval(*)(short, int, u32, void *, u16, xpc_notify_func,
               void *))xpc_notloaded,
    (void (*)(short, int, void *))xpc_notloaded,
    (enum xp_retval(*)(short, void *))xpc_notloaded
};
EXPORT_SYMBOL_GPL(xpc_interface);

/*
 * XPC calls this when it (the XPC module) has been loaded.
 */
void
xpc_set_interface(void (*connect) (int),
          void (*disconnect) (int),
          enum xp_retval (*send) (short, int, u32, void *, u16),
          enum xp_retval (*send_notify) (short, int, u32, void *, u16,
                          xpc_notify_func, void *),
          void (*received) (short, int, void *),
          enum xp_retval (*partid_to_nasids) (short, void *))
{
    xpc_interface.connect = connect;
    xpc_interface.disconnect = disconnect;
    xpc_interface.send = send;
    xpc_interface.send_notify = send_notify;
    xpc_interface.received = received;
    xpc_interface.partid_to_nasids = partid_to_nasids;
}
EXPORT_SYMBOL_GPL(xpc_set_interface);

/*
 * 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.send = (enum xp_retval(*)(short, int, u32, void *, u16))
        xpc_notloaded;
    xpc_interface.send_notify = (enum xp_retval(*)(short, int, u32, void *,
                               u16, xpc_notify_func,
                               void *))xpc_notloaded;
    xpc_interface.received = (void (*)(short, int, void *))
        xpc_notloaded;
    xpc_interface.partid_to_nasids = (enum xp_retval(*)(short, void *))
        xpc_notloaded;
}
EXPORT_SYMBOL_GPL(xpc_clear_interface);

/*
 * 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 xpConnected 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 xp_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_MAX_NCHANNELS);
    DBUG_ON(payload_size == 0 || nentries == 0);
    DBUG_ON(func == NULL);
    DBUG_ON(assigned_limit == 0 || idle_limit > assigned_limit);

    if (XPC_MSG_SIZE(payload_size) > XPC_MSG_MAX_SIZE)
        return xpPayloadTooBig;

    registration = &xpc_registrations[ch_number];

    if (mutex_lock_interruptible(&registration->mutex) != 0)
        return xpInterrupted;

    /* if XPC_CHANNEL_REGISTERED(ch_number) */
    if (registration->func != NULL) {
        mutex_unlock(&registration->mutex);
        return xpAlreadyRegistered;
    }

    /* register the channel for connection */
    registration->entry_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;

    mutex_unlock(&registration->mutex);

    xpc_interface.connect(ch_number);

    return xpSuccess;
}
EXPORT_SYMBOL_GPL(xpc_connect);

/*
 * 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_MAX_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.
     */
    mutex_lock(&registration->mutex);

    /* if !XPC_CHANNEL_REGISTERED(ch_number) */
    if (registration->func == NULL) {
        mutex_unlock(&registration->mutex);
        return;
    }

    /* remove the connection registration for the specified channel */
    registration->func = NULL;
    registration->key = NULL;
    registration->nentries = 0;
    registration->entry_size = 0;
    registration->assigned_limit = 0;
    registration->idle_limit = 0;

    xpc_interface.disconnect(ch_number);

    mutex_unlock(&registration->mutex);

    return;
}
EXPORT_SYMBOL_GPL(xpc_disconnect);

int __init
xp_init(void)
{
    enum xp_retval ret;
    int ch_number;

    /* initialize the connection registration mutex */
    for (ch_number = 0; ch_number < XPC_MAX_NCHANNELS; ch_number++)
        mutex_init(&xpc_registrations[ch_number].mutex);

    if (is_shub())
        ret = xp_init_sn2();
    else if (is_uv())
        ret = xp_init_uv();
    else
        ret = 0;

    if (ret != xpSuccess)
        return ret;

    return 0;
}

module_init(xp_init);

void __exit
xp_exit(void)
{
    if (is_shub())
        xp_exit_sn2();
    else if (is_uv())
        xp_exit_uv();
}

module_exit(xp_exit);

MODULE_AUTHOR("Silicon Graphics, Inc.");
MODULE_DESCRIPTION("Cross Partition (XP) base");
MODULE_LICENSE("GPL");