/*
* 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 <linux/mutex.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 (mutex_lock_interruptible(®istration->mutex) != 0) {
return xpcInterrupted;
}
/* if XPC_CHANNEL_REGISTERED(ch_number) */
if (registration->func != NULL) {
mutex_unlock(®istration->mutex);
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;
mutex_unlock(®istration->mutex);
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.
*/
mutex_lock(®istration->mutex);
/* if !XPC_CHANNEL_REGISTERED(ch_number) */
if (registration->func == NULL) {
mutex_unlock(®istration->mutex);
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);
mutex_unlock(®istration->mutex);
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 mutex */
for (ch_number = 0; ch_number < XPC_NCHANNELS; ch_number++) {
mutex_init(&xpc_registrations[ch_number].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);
