1 files changed, 179 insertions, 63 deletions

diff --git a/arch/ia64/sn/kernel/xpc_main.c b/arch/ia64/sn/kernel/xpc_main.c
index bb1d5cf30440..feece200b3c3 100644
--- a/arch/ia64/sn/kernel/xpc_main.c
+++ b/arch/ia64/sn/kernel/xpc_main.c
@@ -54,6 +54,7 @@
 #include <linux/interrupt.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
+#include <linux/reboot.h>
 #include <asm/sn/intr.h>
 #include <asm/sn/sn_sal.h>
 #include <asm/uaccess.h>
@@ -82,11 +83,13 @@ struct device *xpc_chan = &xpc_chan_dbg_subname;
 
 /* systune related variables for /proc/sys directories */
 
-static int xpc_hb_min = 1;
-static int xpc_hb_max = 10;
+static int xpc_hb_interval = XPC_HB_DEFAULT_INTERVAL;
+static int xpc_hb_min_interval = 1;
+static int xpc_hb_max_interval = 10;
 
-static int xpc_hb_check_min = 10;
-static int xpc_hb_check_max = 120;
+static int xpc_hb_check_interval = XPC_HB_CHECK_DEFAULT_INTERVAL;
+static int xpc_hb_check_min_interval = 10;
+static int xpc_hb_check_max_interval = 120;
 
 static ctl_table xpc_sys_xpc_hb_dir[] = {
         {
@@ -99,7 +102,8 @@ static ctl_table xpc_sys_xpc_hb_dir[] = {
                 &proc_dointvec_minmax,
                 &sysctl_intvec,
                 NULL,
-                &xpc_hb_min, &xpc_hb_max
+                &xpc_hb_min_interval,
+                &xpc_hb_max_interval
         },
         {
                 2,
@@ -111,7 +115,8 @@ static ctl_table xpc_sys_xpc_hb_dir[] = {
                 &proc_dointvec_minmax,
                 &sysctl_intvec,
                 NULL,
-                &xpc_hb_check_min, &xpc_hb_check_max
+                &xpc_hb_check_min_interval,
+                &xpc_hb_check_max_interval
         },
         {0}
 };
@@ -148,11 +153,11 @@ static DECLARE_WAIT_QUEUE_HEAD(xpc_act_IRQ_wq);
 
 static unsigned long xpc_hb_check_timeout;
 
-/* xpc_hb_checker thread exited notification */
-static DECLARE_MUTEX_LOCKED(xpc_hb_checker_exited);
+/* used as an indication of when the xpc_hb_checker thread is inactive */
+static DECLARE_MUTEX_LOCKED(xpc_hb_checker_inactive);
 
-/* xpc_discovery thread exited notification */
-static DECLARE_MUTEX_LOCKED(xpc_discovery_exited);
+/* used as an indication of when the xpc_discovery thread is inactive */
+static DECLARE_MUTEX_LOCKED(xpc_discovery_inactive);
 
 
 static struct timer_list xpc_hb_timer;
@@ -161,6 +166,30 @@ static struct timer_list xpc_hb_timer;
 static void xpc_kthread_waitmsgs(struct xpc_partition *, struct xpc_channel *);
 
 
+static int xpc_system_reboot(struct notifier_block *, unsigned long, void *);
+static struct notifier_block xpc_reboot_notifier = {
+        .notifier_call = xpc_system_reboot,
+};
+
+
+/*
+ * Timer function to enforce the timelimit on the partition disengage request.
+ */
+static void
+xpc_timeout_partition_disengage_request(unsigned long data)
+{
+        struct xpc_partition *part = (struct xpc_partition *) data;
+
+
+        DBUG_ON(XPC_TICKS < part->disengage_request_timeout);
+
+        (void) xpc_partition_disengaged(part);
+
+        DBUG_ON(part->disengage_request_timeout != 0);
+        DBUG_ON(xpc_partition_engaged(1UL << XPC_PARTID(part)) != 0);
+}
+
+
 /*
  * Notify the heartbeat check thread that an IRQ has been received.
  */
@@ -214,12 +243,6 @@ xpc_hb_checker(void *ignore)
 
         while (!(volatile int) xpc_exiting) {
 
-                /* wait for IRQ or timeout */
-                (void) wait_event_interruptible(xpc_act_IRQ_wq,
-                            (last_IRQ_count < atomic_read(&xpc_act_IRQ_rcvd) ||
-                                        jiffies >= xpc_hb_check_timeout ||
-                                                (volatile int) xpc_exiting));
-
                 dev_dbg(xpc_part, "woke up with %d ticks rem; %d IRQs have "
                         "been received\n",
                         (int) (xpc_hb_check_timeout - jiffies),
@@ -240,6 +263,7 @@ xpc_hb_checker(void *ignore)
                 }
 
 
+                /* check for outstanding IRQs */
                 new_IRQ_count = atomic_read(&xpc_act_IRQ_rcvd);
                 if (last_IRQ_count < new_IRQ_count || force_IRQ != 0) {
                         force_IRQ = 0;
@@ -257,13 +281,19 @@ xpc_hb_checker(void *ignore)
                         xpc_hb_check_timeout = jiffies +
                                            (xpc_hb_check_interval * HZ);
                 }
+
+                /* wait for IRQ or timeout */
+                (void) wait_event_interruptible(xpc_act_IRQ_wq,
+                            (last_IRQ_count < atomic_read(&xpc_act_IRQ_rcvd) ||
+                                        jiffies >= xpc_hb_check_timeout ||
+                                                (volatile int) xpc_exiting));
         }
 
         dev_dbg(xpc_part, "heartbeat checker is exiting\n");
 
 
         /* mark this thread as inactive */
-        up(&xpc_hb_checker_exited);
+        up(&xpc_hb_checker_inactive);
         return 0;
 }
 
@@ -283,7 +313,7 @@ xpc_initiate_discovery(void *ignore)
         dev_dbg(xpc_part, "discovery thread is exiting\n");
 
         /* mark this thread as inactive */
-        up(&xpc_discovery_exited);
+        up(&xpc_discovery_inactive);
         return 0;
 }
 
@@ -309,7 +339,7 @@ xpc_make_first_contact(struct xpc_partition *part)
                         "partition %d\n", XPC_PARTID(part));
 
                 /* wait a 1/4 of a second or so */
-                msleep_interruptible(250);
+                (void) msleep_interruptible(250);
 
                 if (part->act_state == XPC_P_DEACTIVATING) {
                         return part->reason;
@@ -336,7 +366,8 @@ static void
 xpc_channel_mgr(struct xpc_partition *part)
 {
         while (part->act_state != XPC_P_DEACTIVATING ||
-                                atomic_read(&part->nchannels_active) > 0) {
+                        atomic_read(&part->nchannels_active) > 0 ||
+                                        !xpc_partition_disengaged(part)) {
 
                 xpc_process_channel_activity(part);
 
@@ -360,7 +391,8 @@ xpc_channel_mgr(struct xpc_partition *part)
                                 (volatile u64) part->local_IPI_amo != 0 ||
                                 ((volatile u8) part->act_state ==
                                                         XPC_P_DEACTIVATING &&
-                                atomic_read(&part->nchannels_active) == 0)));
+                                atomic_read(&part->nchannels_active) == 0 &&
+                                xpc_partition_disengaged(part))));
                 atomic_set(&part->channel_mgr_requests, 1);
 
                 // >>> Does it need to wakeup periodically as well? In case we
@@ -482,7 +514,7 @@ xpc_activating(void *__partid)
                 return 0;
         }
 
-        XPC_ALLOW_HB(partid, xpc_vars);
+        xpc_allow_hb(partid, xpc_vars);
         xpc_IPI_send_activated(part);
 
 
@@ -492,6 +524,7 @@ xpc_activating(void *__partid)
          */
         (void) xpc_partition_up(part);
 
+        xpc_disallow_hb(partid, xpc_vars);
         xpc_mark_partition_inactive(part);
 
         if (part->reason == xpcReactivating) {
@@ -704,11 +737,14 @@ xpc_daemonize_kthread(void *args)
                 xpc_kthread_waitmsgs(part, ch);
         }
 
-        if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
-                        ((ch->flags & XPC_C_CONNECTCALLOUT) ||
-                                (ch->reason != xpcUnregistering &&
-                                        ch->reason != xpcOtherUnregistering))) {
-                xpc_disconnected_callout(ch);
+        if (atomic_dec_return(&ch->kthreads_assigned) == 0) {
+                if (ch->flags & XPC_C_CONNECTCALLOUT) {
+                        xpc_disconnecting_callout(ch);
+                }
+                if (atomic_dec_return(&part->nchannels_engaged) == 0) {
+                        xpc_mark_partition_disengaged(part);
+                        xpc_IPI_send_disengage(part);
+                }
         }
 
 
@@ -740,6 +776,7 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed)
         unsigned long irq_flags;
         pid_t pid;
         u64 args = XPC_PACK_ARGS(ch->partid, ch->number);
+        struct xpc_partition *part = &xpc_partitions[ch->partid];
 
 
         while (needed-- > 0) {
@@ -770,9 +807,13 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed)
                  * kthread. That kthread is responsible for doing the
                  * counterpart to the following before it exits.
                  */
-                (void) xpc_part_ref(&xpc_partitions[ch->partid]);
+                (void) xpc_part_ref(part);
                 xpc_msgqueue_ref(ch);
-                atomic_inc(&ch->kthreads_assigned);
+                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!!!
         }
 }
@@ -781,6 +822,7 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed)
 void
 xpc_disconnect_wait(int ch_number)
 {
+        unsigned long irq_flags;
         partid_t partid;
         struct xpc_partition *part;
         struct xpc_channel *ch;
@@ -793,10 +835,13 @@ xpc_disconnect_wait(int ch_number)
                 if (xpc_part_ref(part)) {
                         ch = &part->channels[ch_number];
 
-// >>> how do we keep from falling into the window between our check and going
-// >>> down and coming back up where sema is re-inited?
-                        if (ch->flags & XPC_C_SETUP) {
-                                (void) down(&ch->teardown_sema);
+                        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);
@@ -806,62 +851,89 @@ xpc_disconnect_wait(int ch_number)
 
 
 static void
-xpc_do_exit(void)
+xpc_do_exit(enum xpc_retval reason)
 {
         partid_t partid;
         int active_part_count;
         struct xpc_partition *part;
+        unsigned long printmsg_time;
 
 
-        /* now it's time to eliminate our heartbeat */
-        del_timer_sync(&xpc_hb_timer);
-        xpc_vars->heartbeating_to_mask = 0;
-
-        /* indicate to others that our reserved page is uninitialized */
-        xpc_rsvd_page->vars_pa = 0;
+        /* a 'rmmod XPC' and a 'reboot' cannot both end up here together */
+        DBUG_ON(xpc_exiting == 1);
 
         /*
-         * Ignore all incoming interrupts. Without interupts the heartbeat
-         * checker won't activate any new partitions that may come up.
-         */
-        free_irq(SGI_XPC_ACTIVATE, NULL);
-
-        /*
-         * Cause the heartbeat checker and the discovery threads to exit.
-         * We don't want them attempting to activate new partitions as we
-         * try to deactivate the existing ones.
+         * Let the heartbeat checker thread and the discovery thread
+         * (if one is running) know that they should exit. Also wake up
+         * the heartbeat checker thread in case it's sleeping.
          */
         xpc_exiting = 1;
         wake_up_interruptible(&xpc_act_IRQ_wq);
 
-        /* wait for the heartbeat checker thread to mark itself inactive */
-        down(&xpc_hb_checker_exited);
+        /* ignore all incoming interrupts */
+        free_irq(SGI_XPC_ACTIVATE, NULL);
 
         /* wait for the discovery thread to mark itself inactive */
-        down(&xpc_discovery_exited);
+        down(&xpc_discovery_inactive);
+
+        /* wait for the heartbeat checker thread to mark itself inactive */
+        down(&xpc_hb_checker_inactive);
 
 
-        msleep_interruptible(300);
+        /* sleep for a 1/3 of a second or so */
+        (void) msleep_interruptible(300);
 
 
         /* wait for all partitions to become inactive */
 
+        printmsg_time = jiffies;
+
         do {
                 active_part_count = 0;
 
                 for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
                         part = &xpc_partitions[partid];
-                        if (part->act_state != XPC_P_INACTIVE) {
-                                active_part_count++;
-
-                                XPC_DEACTIVATE_PARTITION(part, xpcUnloading);
+                        if (xpc_partition_disengaged(part) &&
+                                        part->act_state == XPC_P_INACTIVE) {
+                                continue;
                         }
+
+                        active_part_count++;
+
+                        XPC_DEACTIVATE_PARTITION(part, reason);
+                }
+
+                if (active_part_count == 0) {
+                        break;
+                }
+
+                if (jiffies >= printmsg_time) {
+                        dev_info(xpc_part, "waiting for partitions to "
+                                "deactivate/disengage, active count=%d, remote "
+                                "engaged=0x%lx\n", active_part_count,
+                                xpc_partition_engaged(1UL << partid));
+
+                        printmsg_time = jiffies +
+                                        (XPC_DISENGAGE_PRINTMSG_INTERVAL * HZ);
                 }
 
-                if (active_part_count)
-                        msleep_interruptible(300);
-        } while (active_part_count > 0);
+                /* sleep for a 1/3 of a second or so */
+                (void) msleep_interruptible(300);
+
+        } while (1);
+
+        DBUG_ON(xpc_partition_engaged(-1UL));
+
+
+        /* indicate to others that our reserved page is uninitialized */
+        xpc_rsvd_page->vars_pa = 0;
+
+        /* now it's time to eliminate our heartbeat */
+        del_timer_sync(&xpc_hb_timer);
+        DBUG_ON(xpc_vars->heartbeating_to_mask == 0);
 
+        /* take ourselves off of the reboot_notifier_list */
+        (void) unregister_reboot_notifier(&xpc_reboot_notifier);
 
         /* close down protections for IPI operations */
         xpc_restrict_IPI_ops();
@@ -876,6 +948,34 @@ xpc_do_exit(void)
 }
 
 
+/*
+ * This function is called when the system is being rebooted.
+ */
+static int
+xpc_system_reboot(struct notifier_block *nb, unsigned long event, void *unused)
+{
+        enum xpc_retval reason;
+
+
+        switch (event) {
+        case SYS_RESTART:
+                reason = xpcSystemReboot;
+                break;
+        case SYS_HALT:
+                reason = xpcSystemHalt;
+                break;
+        case SYS_POWER_OFF:
+                reason = xpcSystemPoweroff;
+                break;
+        default:
+                reason = xpcSystemGoingDown;
+        }
+
+        xpc_do_exit(reason);
+        return NOTIFY_DONE;
+}
+
+
 int __init
 xpc_init(void)
 {
@@ -920,6 +1020,12 @@ xpc_init(void)
                 spin_lock_init(&part->act_lock);
                 part->act_state = XPC_P_INACTIVE;
                 XPC_SET_REASON(part, 0, 0);
+
+                init_timer(&part->disengage_request_timer);
+                part->disengage_request_timer.function =
+                                xpc_timeout_partition_disengage_request;
+                part->disengage_request_timer.data = (unsigned long) part;
+
                 part->setup_state = XPC_P_UNSET;
                 init_waitqueue_head(&part->teardown_wq);
                 atomic_set(&part->references, 0);
@@ -976,6 +1082,13 @@ xpc_init(void)
         }
 
 
+        /* add ourselves to the reboot_notifier_list */
+        ret = register_reboot_notifier(&xpc_reboot_notifier);
+        if (ret != 0) {
+                dev_warn(xpc_part, "can't register reboot notifier\n");
+        }
+
+
         /*
          * Set the beating to other partitions into motion.  This is
          * the last requirement for other partitions' discovery to
@@ -997,6 +1110,9 @@ xpc_init(void)
                 /* indicate to others that our reserved page is uninitialized */
                 xpc_rsvd_page->vars_pa = 0;
 
+                /* take ourselves off of the reboot_notifier_list */
+                (void) unregister_reboot_notifier(&xpc_reboot_notifier);
+
                 del_timer_sync(&xpc_hb_timer);
                 free_irq(SGI_XPC_ACTIVATE, NULL);
                 xpc_restrict_IPI_ops();
@@ -1018,9 +1134,9 @@ xpc_init(void)
                 dev_err(xpc_part, "failed while forking discovery thread\n");
 
                 /* mark this new thread as a non-starter */
-                up(&xpc_discovery_exited);
+                up(&xpc_discovery_inactive);
 
-                xpc_do_exit();
+                xpc_do_exit(xpcUnloading);
                 return -EBUSY;
         }
 
@@ -1039,7 +1155,7 @@ module_init(xpc_init);
 void __exit
 xpc_exit(void)
 {
-        xpc_do_exit();
+        xpc_do_exit(xpcUnloading);
 }
 module_exit(xpc_exit);