[IA64-SGI] fixes for XPC disengage and open/close protocol
This patch addresses a few issues with the open/close protocol that
were revealed by the newly added disengage functionality combined
with more extensive testing.
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/sn/kernel/xpc.h b/arch/ia64/sn/kernel/xpc.h
index 565822a..ae51d7b 100644
--- a/arch/ia64/sn/kernel/xpc.h
+++ b/arch/ia64/sn/kernel/xpc.h
@@ -417,6 +417,9 @@
atomic_t n_on_msg_allocate_wq; /* #on msg allocation wait queue */
wait_queue_head_t msg_allocate_wq; /* msg allocation wait queue */
+ u8 delayed_IPI_flags; /* IPI flags received, but delayed */
+ /* action until channel disconnected */
+
/* queue of msg senders who want to be notified when msg received */
atomic_t n_to_notify; /* #of msg senders to notify */
@@ -478,7 +481,8 @@
#define XPC_C_DISCONNECTED 0x00002000 /* channel is disconnected */
#define XPC_C_DISCONNECTING 0x00004000 /* channel is being disconnected */
-#define XPC_C_WDISCONNECT 0x00008000 /* waiting for channel disconnect */
+#define XPC_C_DISCONNECTCALLOUT 0x00008000 /* chan disconnected callout made */
+#define XPC_C_WDISCONNECT 0x00010000 /* waiting for channel disconnect */
@@ -508,13 +512,13 @@
int reason_line; /* line# deactivation initiated from */
int reactivate_nasid; /* nasid in partition to reactivate */
- unsigned long disengage_request_timeout; /* timeout in XPC_TICKS */
+ unsigned long disengage_request_timeout; /* timeout in jiffies */
struct timer_list disengage_request_timer;
/* XPC infrastructure referencing and teardown control */
- volatile u8 setup_state; /* infrastructure setup state */
+ volatile u8 setup_state; /* infrastructure setup state */
wait_queue_head_t teardown_wq; /* kthread waiting to teardown infra */
atomic_t references; /* #of references to infrastructure */
@@ -604,7 +608,7 @@
/* number of seconds to wait for other partitions to disengage */
-#define XPC_DISENGAGE_REQUEST_TIMELIMIT 90
+#define XPC_DISENGAGE_REQUEST_DEFAULT_TIMELIMIT 90
/* interval in seconds to print 'waiting disengagement' messages */
#define XPC_DISENGAGE_PRINTMSG_INTERVAL 10
@@ -618,20 +622,18 @@
extern struct xpc_registration xpc_registrations[];
-/* >>> found in xpc_main.c only */
+/* found in xpc_main.c */
extern struct device *xpc_part;
extern struct device *xpc_chan;
+extern int xpc_disengage_request_timelimit;
extern irqreturn_t xpc_notify_IRQ_handler(int, void *, struct pt_regs *);
extern void xpc_dropped_IPI_check(struct xpc_partition *);
+extern void xpc_activate_partition(struct xpc_partition *);
extern void xpc_activate_kthreads(struct xpc_channel *, int);
extern void xpc_create_kthreads(struct xpc_channel *, int);
extern void xpc_disconnect_wait(int);
-/* found in xpc_main.c and efi-xpc.c */
-extern void xpc_activate_partition(struct xpc_partition *);
-
-
/* found in xpc_partition.c */
extern int xpc_exiting;
extern struct xpc_vars *xpc_vars;
@@ -1077,6 +1079,7 @@
/* given an AMO variable and a channel#, get its associated IPI flags */
#define XPC_GET_IPI_FLAGS(_amo, _c) ((u8) (((_amo) >> ((_c) * 8)) & 0xff))
+#define XPC_SET_IPI_FLAGS(_amo, _c, _f) (_amo) |= ((u64) (_f) << ((_c) * 8))
#define XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(_amo) ((_amo) & 0x0f0f0f0f0f0f0f0f)
#define XPC_ANY_MSG_IPI_FLAGS_SET(_amo) ((_amo) & 0x1010101010101010)
diff --git a/arch/ia64/sn/kernel/xpc_channel.c b/arch/ia64/sn/kernel/xpc_channel.c
index 195ac1b..abf4fc2 100644
--- a/arch/ia64/sn/kernel/xpc_channel.c
+++ b/arch/ia64/sn/kernel/xpc_channel.c
@@ -792,11 +792,20 @@
"reason=%d\n", ch->number, ch->partid, ch->reason);
}
- /* wake the thread that is waiting for this channel to disconnect */
if (ch->flags & XPC_C_WDISCONNECT) {
spin_unlock_irqrestore(&ch->lock, *irq_flags);
up(&ch->wdisconnect_sema);
spin_lock_irqsave(&ch->lock, *irq_flags);
+
+ } else if (ch->delayed_IPI_flags) {
+ if (part->act_state != XPC_P_DEACTIVATING) {
+ /* time to take action on any delayed IPI flags */
+ spin_lock(&part->IPI_lock);
+ XPC_SET_IPI_FLAGS(part->local_IPI_amo, ch->number,
+ ch->delayed_IPI_flags);
+ spin_unlock(&part->IPI_lock);
+ }
+ ch->delayed_IPI_flags = 0;
}
}
@@ -818,6 +827,19 @@
spin_lock_irqsave(&ch->lock, irq_flags);
+again:
+
+ if ((ch->flags & XPC_C_DISCONNECTED) &&
+ (ch->flags & XPC_C_WDISCONNECT)) {
+ /*
+ * Delay processing IPI flags until thread waiting disconnect
+ * has had a chance to see that the channel is disconnected.
+ */
+ ch->delayed_IPI_flags |= IPI_flags;
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+ return;
+ }
+
if (IPI_flags & XPC_IPI_CLOSEREQUEST) {
@@ -843,14 +865,22 @@
/* both sides have finished disconnecting */
xpc_process_disconnect(ch, &irq_flags);
+ DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED));
+ goto again;
}
if (ch->flags & XPC_C_DISCONNECTED) {
- // >>> explain this section
-
if (!(IPI_flags & XPC_IPI_OPENREQUEST)) {
- DBUG_ON(part->act_state !=
- XPC_P_DEACTIVATING);
+ if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo,
+ ch_number) & XPC_IPI_OPENREQUEST)) {
+
+ DBUG_ON(ch->delayed_IPI_flags != 0);
+ spin_lock(&part->IPI_lock);
+ XPC_SET_IPI_FLAGS(part->local_IPI_amo,
+ ch_number,
+ XPC_IPI_CLOSEREQUEST);
+ spin_unlock(&part->IPI_lock);
+ }
spin_unlock_irqrestore(&ch->lock, irq_flags);
return;
}
@@ -880,9 +910,13 @@
}
XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
- } else {
- xpc_process_disconnect(ch, &irq_flags);
+
+ DBUG_ON(IPI_flags & XPC_IPI_CLOSEREPLY);
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+ return;
}
+
+ xpc_process_disconnect(ch, &irq_flags);
}
@@ -898,7 +932,20 @@
}
DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
- DBUG_ON(!(ch->flags & XPC_C_RCLOSEREQUEST));
+
+ if (!(ch->flags & XPC_C_RCLOSEREQUEST)) {
+ if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo, ch_number)
+ & XPC_IPI_CLOSEREQUEST)) {
+
+ DBUG_ON(ch->delayed_IPI_flags != 0);
+ spin_lock(&part->IPI_lock);
+ XPC_SET_IPI_FLAGS(part->local_IPI_amo,
+ ch_number, XPC_IPI_CLOSEREPLY);
+ spin_unlock(&part->IPI_lock);
+ }
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+ return;
+ }
ch->flags |= XPC_C_RCLOSEREPLY;
@@ -916,8 +963,14 @@
"channel=%d\n", args->msg_size, args->local_nentries,
ch->partid, ch->number);
- if ((ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) ||
- part->act_state == XPC_P_DEACTIVATING) {
+ if (part->act_state == XPC_P_DEACTIVATING ||
+ (ch->flags & XPC_C_ROPENREQUEST)) {
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+ return;
+ }
+
+ if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) {
+ ch->delayed_IPI_flags |= XPC_IPI_OPENREQUEST;
spin_unlock_irqrestore(&ch->lock, irq_flags);
return;
}
@@ -931,8 +984,11 @@
* msg_size = size of channel's messages in bytes
* local_nentries = remote partition's local_nentries
*/
- DBUG_ON(args->msg_size == 0);
- DBUG_ON(args->local_nentries == 0);
+ if (args->msg_size == 0 || args->local_nentries == 0) {
+ /* assume OPENREQUEST was delayed by mistake */
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+ return;
+ }
ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING);
ch->remote_nentries = args->local_nentries;
@@ -970,7 +1026,13 @@
spin_unlock_irqrestore(&ch->lock, irq_flags);
return;
}
- DBUG_ON(!(ch->flags & XPC_C_OPENREQUEST));
+ if (!(ch->flags & XPC_C_OPENREQUEST)) {
+ XPC_DISCONNECT_CHANNEL(ch, xpcOpenCloseError,
+ &irq_flags);
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+ return;
+ }
+
DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST));
DBUG_ON(ch->flags & XPC_C_CONNECTED);
@@ -1024,8 +1086,8 @@
struct xpc_registration *registration = &xpc_registrations[ch->number];
- if (down_interruptible(®istration->sema) != 0) {
- return xpcInterrupted;
+ if (down_trylock(®istration->sema) != 0) {
+ return xpcRetry;
}
if (!XPC_CHANNEL_REGISTERED(ch->number)) {
@@ -1445,19 +1507,11 @@
if (xpc_part_ref(part)) {
ch = &part->channels[ch_number];
- if (!(ch->flags & XPC_C_DISCONNECTING)) {
- DBUG_ON(ch->flags & XPC_C_OPENREQUEST);
- DBUG_ON(ch->flags & XPC_C_CONNECTED);
- DBUG_ON(ch->flags & XPC_C_SETUP);
-
- /*
- * Initiate the establishment of a connection
- * on the newly registered channel to the
- * remote partition.
- */
- xpc_wakeup_channel_mgr(part);
- }
-
+ /*
+ * Initiate the establishment of a connection on the
+ * newly registered channel to the remote partition.
+ */
+ xpc_wakeup_channel_mgr(part);
xpc_part_deref(part);
}
}
@@ -1467,9 +1521,6 @@
void
xpc_connected_callout(struct xpc_channel *ch)
{
- unsigned long irq_flags;
-
-
/* let the registerer know that a connection has been established */
if (ch->func != NULL) {
@@ -1482,10 +1533,6 @@
dev_dbg(xpc_chan, "ch->func() returned, reason=xpcConnected, "
"partid=%d, channel=%d\n", ch->partid, ch->number);
}
-
- spin_lock_irqsave(&ch->lock, irq_flags);
- ch->flags |= XPC_C_CONNECTCALLOUT;
- spin_unlock_irqrestore(&ch->lock, irq_flags);
}
diff --git a/arch/ia64/sn/kernel/xpc_main.c b/arch/ia64/sn/kernel/xpc_main.c
index feece20..db349c6 100644
--- a/arch/ia64/sn/kernel/xpc_main.c
+++ b/arch/ia64/sn/kernel/xpc_main.c
@@ -91,6 +91,10 @@
static int xpc_hb_check_min_interval = 10;
static int xpc_hb_check_max_interval = 120;
+int xpc_disengage_request_timelimit = XPC_DISENGAGE_REQUEST_DEFAULT_TIMELIMIT;
+static int xpc_disengage_request_min_timelimit = 0;
+static int xpc_disengage_request_max_timelimit = 120;
+
static ctl_table xpc_sys_xpc_hb_dir[] = {
{
1,
@@ -129,6 +133,19 @@
0555,
xpc_sys_xpc_hb_dir
},
+ {
+ 2,
+ "disengage_request_timelimit",
+ &xpc_disengage_request_timelimit,
+ sizeof(int),
+ 0644,
+ NULL,
+ &proc_dointvec_minmax,
+ &sysctl_intvec,
+ NULL,
+ &xpc_disengage_request_min_timelimit,
+ &xpc_disengage_request_max_timelimit
+ },
{0}
};
static ctl_table xpc_sys_dir[] = {
@@ -153,11 +170,11 @@
static unsigned long xpc_hb_check_timeout;
-/* used as an indication of when the xpc_hb_checker thread is inactive */
-static DECLARE_MUTEX_LOCKED(xpc_hb_checker_inactive);
+/* notification that the xpc_hb_checker thread has exited */
+static DECLARE_MUTEX_LOCKED(xpc_hb_checker_exited);
-/* used as an indication of when the xpc_discovery thread is inactive */
-static DECLARE_MUTEX_LOCKED(xpc_discovery_inactive);
+/* notification that the xpc_discovery thread has exited */
+static DECLARE_MUTEX_LOCKED(xpc_discovery_exited);
static struct timer_list xpc_hb_timer;
@@ -181,7 +198,7 @@
struct xpc_partition *part = (struct xpc_partition *) data;
- DBUG_ON(XPC_TICKS < part->disengage_request_timeout);
+ DBUG_ON(jiffies < part->disengage_request_timeout);
(void) xpc_partition_disengaged(part);
@@ -292,8 +309,8 @@
dev_dbg(xpc_part, "heartbeat checker is exiting\n");
- /* mark this thread as inactive */
- up(&xpc_hb_checker_inactive);
+ /* mark this thread as having exited */
+ up(&xpc_hb_checker_exited);
return 0;
}
@@ -312,8 +329,8 @@
dev_dbg(xpc_part, "discovery thread is exiting\n");
- /* mark this thread as inactive */
- up(&xpc_discovery_inactive);
+ /* mark this thread as having exited */
+ up(&xpc_discovery_exited);
return 0;
}
@@ -703,6 +720,7 @@
struct xpc_partition *part = &xpc_partitions[partid];
struct xpc_channel *ch;
int n_needed;
+ unsigned long irq_flags;
daemonize("xpc%02dc%d", partid, ch_number);
@@ -713,11 +731,14 @@
ch = &part->channels[ch_number];
if (!(ch->flags & XPC_C_DISCONNECTING)) {
- DBUG_ON(!(ch->flags & XPC_C_CONNECTED));
/* let registerer know that connection has been established */
- if (atomic_read(&ch->kthreads_assigned) == 1) {
+ spin_lock_irqsave(&ch->lock, irq_flags);
+ if (!(ch->flags & XPC_C_CONNECTCALLOUT)) {
+ ch->flags |= XPC_C_CONNECTCALLOUT;
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+
xpc_connected_callout(ch);
/*
@@ -732,14 +753,23 @@
!(ch->flags & XPC_C_DISCONNECTING)) {
xpc_activate_kthreads(ch, n_needed);
}
+ } else {
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
}
xpc_kthread_waitmsgs(part, ch);
}
if (atomic_dec_return(&ch->kthreads_assigned) == 0) {
- if (ch->flags & XPC_C_CONNECTCALLOUT) {
+ spin_lock_irqsave(&ch->lock, irq_flags);
+ if ((ch->flags & XPC_C_CONNECTCALLOUT) &&
+ !(ch->flags & XPC_C_DISCONNECTCALLOUT)) {
+ ch->flags |= XPC_C_DISCONNECTCALLOUT;
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+
xpc_disconnecting_callout(ch);
+ } else {
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
}
if (atomic_dec_return(&part->nchannels_engaged) == 0) {
xpc_mark_partition_disengaged(part);
@@ -780,9 +810,29 @@
while (needed-- > 0) {
+
+ /*
+ * The following is done on behalf of the newly created
+ * kthread. That kthread is responsible for doing the
+ * counterpart to the following before it exits.
+ */
+ (void) xpc_part_ref(part);
+ xpc_msgqueue_ref(ch);
+ if (atomic_inc_return(&ch->kthreads_assigned) == 1 &&
+ atomic_inc_return(&part->nchannels_engaged) == 1) {
+ xpc_mark_partition_engaged(part);
+ }
+
pid = kernel_thread(xpc_daemonize_kthread, (void *) args, 0);
if (pid < 0) {
/* the fork failed */
+ if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
+ atomic_dec_return(&part->nchannels_engaged) == 0) {
+ xpc_mark_partition_disengaged(part);
+ xpc_IPI_send_disengage(part);
+ }
+ xpc_msgqueue_deref(ch);
+ xpc_part_deref(part);
if (atomic_read(&ch->kthreads_assigned) <
ch->kthreads_idle_limit) {
@@ -802,18 +852,6 @@
break;
}
- /*
- * The following is done on behalf of the newly created
- * kthread. That kthread is responsible for doing the
- * counterpart to the following before it exits.
- */
- (void) xpc_part_ref(part);
- xpc_msgqueue_ref(ch);
- if (atomic_inc_return(&ch->kthreads_assigned) == 1) {
- if (atomic_inc_return(&part->nchannels_engaged) == 1) {
- xpc_mark_partition_engaged(part);
- }
- }
ch->kthreads_created++; // >>> temporary debug only!!!
}
}
@@ -826,26 +864,49 @@
partid_t partid;
struct xpc_partition *part;
struct xpc_channel *ch;
+ int wakeup_channel_mgr;
/* now wait for all callouts to the caller's function to cease */
for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
part = &xpc_partitions[partid];
- if (xpc_part_ref(part)) {
- ch = &part->channels[ch_number];
-
- if (ch->flags & XPC_C_WDISCONNECT) {
- if (!(ch->flags & XPC_C_DISCONNECTED)) {
- (void) down(&ch->wdisconnect_sema);
- }
- spin_lock_irqsave(&ch->lock, irq_flags);
- ch->flags &= ~XPC_C_WDISCONNECT;
- spin_unlock_irqrestore(&ch->lock, irq_flags);
- }
-
- xpc_part_deref(part);
+ if (!xpc_part_ref(part)) {
+ continue;
}
+
+ ch = &part->channels[ch_number];
+
+ if (!(ch->flags & XPC_C_WDISCONNECT)) {
+ xpc_part_deref(part);
+ continue;
+ }
+
+ (void) down(&ch->wdisconnect_sema);
+
+ spin_lock_irqsave(&ch->lock, irq_flags);
+ DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED));
+ wakeup_channel_mgr = 0;
+
+ if (ch->delayed_IPI_flags) {
+ if (part->act_state != XPC_P_DEACTIVATING) {
+ spin_lock(&part->IPI_lock);
+ XPC_SET_IPI_FLAGS(part->local_IPI_amo,
+ ch->number, ch->delayed_IPI_flags);
+ spin_unlock(&part->IPI_lock);
+ wakeup_channel_mgr = 1;
+ }
+ ch->delayed_IPI_flags = 0;
+ }
+
+ ch->flags &= ~XPC_C_WDISCONNECT;
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+
+ if (wakeup_channel_mgr) {
+ xpc_wakeup_channel_mgr(part);
+ }
+
+ xpc_part_deref(part);
}
}
@@ -873,11 +934,11 @@
/* ignore all incoming interrupts */
free_irq(SGI_XPC_ACTIVATE, NULL);
- /* wait for the discovery thread to mark itself inactive */
- down(&xpc_discovery_inactive);
+ /* wait for the discovery thread to exit */
+ down(&xpc_discovery_exited);
- /* wait for the heartbeat checker thread to mark itself inactive */
- down(&xpc_hb_checker_inactive);
+ /* wait for the heartbeat checker thread to exit */
+ down(&xpc_hb_checker_exited);
/* sleep for a 1/3 of a second or so */
@@ -893,6 +954,7 @@
for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
part = &xpc_partitions[partid];
+
if (xpc_partition_disengaged(part) &&
part->act_state == XPC_P_INACTIVE) {
continue;
@@ -930,7 +992,7 @@
/* now it's time to eliminate our heartbeat */
del_timer_sync(&xpc_hb_timer);
- DBUG_ON(xpc_vars->heartbeating_to_mask == 0);
+ DBUG_ON(xpc_vars->heartbeating_to_mask != 0);
/* take ourselves off of the reboot_notifier_list */
(void) unregister_reboot_notifier(&xpc_reboot_notifier);
@@ -1134,7 +1196,7 @@
dev_err(xpc_part, "failed while forking discovery thread\n");
/* mark this new thread as a non-starter */
- up(&xpc_discovery_inactive);
+ up(&xpc_discovery_exited);
xpc_do_exit(xpcUnloading);
return -EBUSY;
@@ -1172,3 +1234,7 @@
MODULE_PARM_DESC(xpc_hb_check_interval, "Number of seconds between "
"heartbeat checks.");
+module_param(xpc_disengage_request_timelimit, int, 0);
+MODULE_PARM_DESC(xpc_disengage_request_timelimit, "Number of seconds to wait "
+ "for disengage request to complete.");
+
diff --git a/arch/ia64/sn/kernel/xpc_partition.c b/arch/ia64/sn/kernel/xpc_partition.c
index 79a0fc4c..958488f 100644
--- a/arch/ia64/sn/kernel/xpc_partition.c
+++ b/arch/ia64/sn/kernel/xpc_partition.c
@@ -578,7 +578,7 @@
/*
- * Prior code has determine the nasid which generated an IPI. Inspect
+ * Prior code has determined the nasid which generated an IPI. Inspect
* that nasid to determine if its partition needs to be activated or
* deactivated.
*
@@ -942,14 +942,14 @@
/* set a timelimit on the disengage request */
part->disengage_request_timeout = jiffies +
- (XPC_DISENGAGE_REQUEST_TIMELIMIT * HZ);
+ (xpc_disengage_request_timelimit * HZ);
part->disengage_request_timer.expires =
part->disengage_request_timeout;
add_timer(&part->disengage_request_timer);
}
- dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n", partid,
- reason);
+ dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
+ XPC_PARTID(part), reason);
xpc_partition_going_down(part, reason);
}
diff --git a/include/asm-ia64/sn/xp.h b/include/asm-ia64/sn/xp.h
index f3052a5..30312be 100644
--- a/include/asm-ia64/sn/xp.h
+++ b/include/asm-ia64/sn/xp.h
@@ -225,7 +225,9 @@
xpcDisconnecting, /* 49: channel disconnecting (closing) */
- xpcUnknownReason /* 50: unknown reason -- must be last in list */
+ xpcOpenCloseError, /* 50: channel open/close protocol error */
+
+ xpcUnknownReason /* 51: unknown reason -- must be last in list */
};
@@ -350,7 +352,7 @@
*
* 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
+ * or an incoming message received, or an error condition encountered. A
* non-NULL 'func' field indicates that there is an active registration for
* the channel.
*/