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Diffstat (limited to 'arch/ia64/sn/kernel/xpc_main.c')
| -rw-r--r-- | arch/ia64/sn/kernel/xpc_main.c | 1431 |
1 files changed, 0 insertions, 1431 deletions
diff --git a/arch/ia64/sn/kernel/xpc_main.c b/arch/ia64/sn/kernel/xpc_main.c deleted file mode 100644 index 81785b78bc1e..000000000000 --- a/arch/ia64/sn/kernel/xpc_main.c +++ /dev/null @@ -1,1431 +0,0 @@ -/* - * 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) 2004-2007 Silicon Graphics, Inc. All Rights Reserved. - */ - - -/* - * Cross Partition Communication (XPC) support - standard version. - * - * XPC provides a message passing capability that crosses partition - * boundaries. This module is made up of two parts: - * - * partition This part detects the presence/absence of other - * partitions. It provides a heartbeat and monitors - * the heartbeats of other partitions. - * - * channel This part manages the channels and sends/receives - * messages across them to/from other partitions. - * - * There are a couple of additional functions residing in XP, which - * provide an interface to XPC for its users. - * - * - * Caveats: - * - * . We currently have no way to determine which nasid an IPI came - * from. Thus, xpc_IPI_send() does a remote AMO write followed by - * an IPI. The AMO indicates where data is to be pulled from, so - * after the IPI arrives, the remote partition checks the AMO word. - * The IPI can actually arrive before the AMO however, so other code - * must periodically check for this case. Also, remote AMO operations - * do not reliably time out. Thus we do a remote PIO read solely to - * know whether the remote partition is down and whether we should - * stop sending IPIs to it. This remote PIO read operation is set up - * in a special nofault region so SAL knows to ignore (and cleanup) - * any errors due to the remote AMO write, PIO read, and/or PIO - * write operations. - * - * If/when new hardware solves this IPI problem, we should abandon - * the current approach. - * - */ - - -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/init.h> -#include <linux/sched.h> -#include <linux/syscalls.h> -#include <linux/cache.h> -#include <linux/interrupt.h> -#include <linux/delay.h> -#include <linux/reboot.h> -#include <linux/completion.h> -#include <linux/kdebug.h> -#include <asm/sn/intr.h> -#include <asm/sn/sn_sal.h> -#include <asm/uaccess.h> -#include <asm/sn/xpc.h> - - -/* define two XPC debug device structures to be used with dev_dbg() et al */ - -struct device_driver xpc_dbg_name = { - .name = "xpc" -}; - -struct device xpc_part_dbg_subname = { - .bus_id = {0}, /* set to "part" at xpc_init() time */ - .driver = &xpc_dbg_name -}; - -struct device xpc_chan_dbg_subname = { - .bus_id = {0}, /* set to "chan" at xpc_init() time */ - .driver = &xpc_dbg_name -}; - -struct device *xpc_part = &xpc_part_dbg_subname; -struct device *xpc_chan = &xpc_chan_dbg_subname; - - -static int xpc_kdebug_ignore; - - -/* systune related variables for /proc/sys directories */ - -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_interval = XPC_HB_CHECK_DEFAULT_INTERVAL; -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[] = { - { - .ctl_name = CTL_UNNUMBERED, - .procname = "hb_interval", - .data = &xpc_hb_interval, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = &proc_dointvec_minmax, - .strategy = &sysctl_intvec, - .extra1 = &xpc_hb_min_interval, - .extra2 = &xpc_hb_max_interval - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "hb_check_interval", - .data = &xpc_hb_check_interval, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = &proc_dointvec_minmax, - .strategy = &sysctl_intvec, - .extra1 = &xpc_hb_check_min_interval, - .extra2 = &xpc_hb_check_max_interval - }, - {} -}; -static ctl_table xpc_sys_xpc_dir[] = { - { - .ctl_name = CTL_UNNUMBERED, - .procname = "hb", - .mode = 0555, - .child = xpc_sys_xpc_hb_dir - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "disengage_request_timelimit", - .data = &xpc_disengage_request_timelimit, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = &proc_dointvec_minmax, - .strategy = &sysctl_intvec, - .extra1 = &xpc_disengage_request_min_timelimit, - .extra2 = &xpc_disengage_request_max_timelimit - }, - {} -}; -static ctl_table xpc_sys_dir[] = { - { - .ctl_name = CTL_UNNUMBERED, - .procname = "xpc", - .mode = 0555, - .child = xpc_sys_xpc_dir - }, - {} -}; -static struct ctl_table_header *xpc_sysctl; - -/* non-zero if any remote partition disengage request was timed out */ -int xpc_disengage_request_timedout; - -/* #of IRQs received */ -static atomic_t xpc_act_IRQ_rcvd; - -/* IRQ handler notifies this wait queue on receipt of an IRQ */ -static DECLARE_WAIT_QUEUE_HEAD(xpc_act_IRQ_wq); - -static unsigned long xpc_hb_check_timeout; - -/* notification that the xpc_hb_checker thread has exited */ -static DECLARE_COMPLETION(xpc_hb_checker_exited); - -/* notification that the xpc_discovery thread has exited */ -static DECLARE_COMPLETION(xpc_discovery_exited); - - -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, -}; - -static int xpc_system_die(struct notifier_block *, unsigned long, void *); -static struct notifier_block xpc_die_notifier = { - .notifier_call = xpc_system_die, -}; - - -/* - * 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(jiffies < 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. - */ -static irqreturn_t -xpc_act_IRQ_handler(int irq, void *dev_id) -{ - atomic_inc(&xpc_act_IRQ_rcvd); - wake_up_interruptible(&xpc_act_IRQ_wq); - return IRQ_HANDLED; -} - - -/* - * Timer to produce the heartbeat. The timer structures function is - * already set when this is initially called. A tunable is used to - * specify when the next timeout should occur. - */ -static void -xpc_hb_beater(unsigned long dummy) -{ - xpc_vars->heartbeat++; - - if (jiffies >= xpc_hb_check_timeout) { - wake_up_interruptible(&xpc_act_IRQ_wq); - } - - xpc_hb_timer.expires = jiffies + (xpc_hb_interval * HZ); - add_timer(&xpc_hb_timer); -} - - -/* - * This thread is responsible for nearly all of the partition - * activation/deactivation. - */ -static int -xpc_hb_checker(void *ignore) -{ - int last_IRQ_count = 0; - int new_IRQ_count; - int force_IRQ=0; - - - /* this thread was marked active by xpc_hb_init() */ - - daemonize(XPC_HB_CHECK_THREAD_NAME); - - set_cpus_allowed(current, cpumask_of_cpu(XPC_HB_CHECK_CPU)); - - /* set our heartbeating to other partitions into motion */ - xpc_hb_check_timeout = jiffies + (xpc_hb_check_interval * HZ); - xpc_hb_beater(0); - - while (!(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), - atomic_read(&xpc_act_IRQ_rcvd) - last_IRQ_count); - - - /* checking of remote heartbeats is skewed by IRQ handling */ - if (jiffies >= xpc_hb_check_timeout) { - dev_dbg(xpc_part, "checking remote heartbeats\n"); - xpc_check_remote_hb(); - - /* - * We need to periodically recheck to ensure no - * IPI/AMO pairs have been missed. That check - * must always reset xpc_hb_check_timeout. - */ - force_IRQ = 1; - } - - - /* 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; - - dev_dbg(xpc_part, "found an IRQ to process; will be " - "resetting xpc_hb_check_timeout\n"); - - last_IRQ_count += xpc_identify_act_IRQ_sender(); - if (last_IRQ_count < new_IRQ_count) { - /* retry once to help avoid missing AMO */ - (void) xpc_identify_act_IRQ_sender(); - } - last_IRQ_count = new_IRQ_count; - - 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 having exited */ - complete(&xpc_hb_checker_exited); - return 0; -} - - -/* - * This thread will attempt to discover other partitions to activate - * based on info provided by SAL. This new thread is short lived and - * will exit once discovery is complete. - */ -static int -xpc_initiate_discovery(void *ignore) -{ - daemonize(XPC_DISCOVERY_THREAD_NAME); - - xpc_discovery(); - - dev_dbg(xpc_part, "discovery thread is exiting\n"); - - /* mark this thread as having exited */ - complete(&xpc_discovery_exited); - return 0; -} - - -/* - * Establish first contact with the remote partititon. This involves pulling - * the XPC per partition variables from the remote partition and waiting for - * the remote partition to pull ours. - */ -static enum xpc_retval -xpc_make_first_contact(struct xpc_partition *part) -{ - enum xpc_retval ret; - - - while ((ret = xpc_pull_remote_vars_part(part)) != xpcSuccess) { - if (ret != xpcRetry) { - XPC_DEACTIVATE_PARTITION(part, ret); - return ret; - } - - dev_dbg(xpc_chan, "waiting to make first contact with " - "partition %d\n", XPC_PARTID(part)); - - /* wait a 1/4 of a second or so */ - (void) msleep_interruptible(250); - - if (part->act_state == XPC_P_DEACTIVATING) { - return part->reason; - } - } - - return xpc_mark_partition_active(part); -} - - -/* - * The first kthread assigned to a newly activated partition is the one - * created by XPC HB with which it calls xpc_partition_up(). XPC hangs on to - * that kthread until the partition is brought down, at which time that kthread - * returns back to XPC HB. (The return of that kthread will signify to XPC HB - * that XPC has dismantled all communication infrastructure for the associated - * partition.) This kthread becomes the channel manager for that partition. - * - * Each active partition has a channel manager, who, besides connecting and - * disconnecting channels, will ensure that each of the partition's connected - * channels has the required number of assigned kthreads to get the work done. - */ -static void -xpc_channel_mgr(struct xpc_partition *part) -{ - while (part->act_state != XPC_P_DEACTIVATING || - atomic_read(&part->nchannels_active) > 0 || - !xpc_partition_disengaged(part)) { - - xpc_process_channel_activity(part); - - - /* - * Wait until we've been requested to activate kthreads or - * all of the channel's message queues have been torn down or - * a signal is pending. - * - * The channel_mgr_requests is set to 1 after being awakened, - * This is done to prevent the channel mgr from making one pass - * through the loop for each request, since he will - * be servicing all the requests in one pass. The reason it's - * set to 1 instead of 0 is so that other kthreads will know - * that the channel mgr is running and won't bother trying to - * wake him up. - */ - atomic_dec(&part->channel_mgr_requests); - (void) wait_event_interruptible(part->channel_mgr_wq, - (atomic_read(&part->channel_mgr_requests) > 0 || - (volatile u64) part->local_IPI_amo != 0 || - ((volatile u8) part->act_state == - XPC_P_DEACTIVATING && - 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 - // >>> miscalculated the #of kthreads to wakeup or create? - } -} - - -/* - * When XPC HB determines that a partition has come up, it will create a new - * kthread and that kthread will call this function to attempt to set up the - * basic infrastructure used for Cross Partition Communication with the newly - * upped partition. - * - * The kthread that was created by XPC HB and which setup the XPC - * infrastructure will remain assigned to the partition until the partition - * goes down. At which time the kthread will teardown the XPC infrastructure - * and then exit. - * - * XPC HB will put the remote partition's XPC per partition specific variables - * physical address into xpc_partitions[partid].remote_vars_part_pa prior to - * calling xpc_partition_up(). - */ -static void -xpc_partition_up(struct xpc_partition *part) -{ - DBUG_ON(part->channels != NULL); - - dev_dbg(xpc_chan, "activating partition %d\n", XPC_PARTID(part)); - - if (xpc_setup_infrastructure(part) != xpcSuccess) { - return; - } - - /* - * The kthread that XPC HB called us with will become the - * channel manager for this partition. It will not return - * back to XPC HB until the partition's XPC infrastructure - * has been dismantled. - */ - - (void) xpc_part_ref(part); /* this will always succeed */ - - if (xpc_make_first_contact(part) == xpcSuccess) { - xpc_channel_mgr(part); - } - - xpc_part_deref(part); - - xpc_teardown_infrastructure(part); -} - - -static int -xpc_activating(void *__partid) -{ - partid_t partid = (u64) __partid; - struct xpc_partition *part = &xpc_partitions[partid]; - unsigned long irq_flags; - struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; - int ret; - - - DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); - - spin_lock_irqsave(&part->act_lock, irq_flags); - - if (part->act_state == XPC_P_DEACTIVATING) { - part->act_state = XPC_P_INACTIVE; - spin_unlock_irqrestore(&part->act_lock, irq_flags); - part->remote_rp_pa = 0; - return 0; - } - - /* indicate the thread is activating */ - DBUG_ON(part->act_state != XPC_P_ACTIVATION_REQ); - part->act_state = XPC_P_ACTIVATING; - - XPC_SET_REASON(part, 0, 0); - spin_unlock_irqrestore(&part->act_lock, irq_flags); - - dev_dbg(xpc_part, "bringing partition %d up\n", partid); - - daemonize("xpc%02d", partid); - - /* - * This thread needs to run at a realtime priority to prevent a - * significant performance degradation. - */ - ret = sched_setscheduler(current, SCHED_FIFO, ¶m); - if (ret != 0) { - dev_warn(xpc_part, "unable to set pid %d to a realtime " - "priority, ret=%d\n", current->pid, ret); - } - - /* allow this thread and its children to run on any CPU */ - set_cpus_allowed(current, CPU_MASK_ALL); - - /* - * Register the remote partition's AMOs with SAL so it can handle - * and cleanup errors within that address range should the remote - * partition go down. We don't unregister this range because it is - * difficult to tell when outstanding writes to the remote partition - * are finished and thus when it is safe to unregister. This should - * not result in wasted space in the SAL xp_addr_region table because - * we should get the same page for remote_amos_page_pa after module - * reloads and system reboots. - */ - if (sn_register_xp_addr_region(part->remote_amos_page_pa, - PAGE_SIZE, 1) < 0) { - dev_warn(xpc_part, "xpc_partition_up(%d) failed to register " - "xp_addr region\n", partid); - - spin_lock_irqsave(&part->act_lock, irq_flags); - part->act_state = XPC_P_INACTIVE; - XPC_SET_REASON(part, xpcPhysAddrRegFailed, __LINE__); - spin_unlock_irqrestore(&part->act_lock, irq_flags); - part->remote_rp_pa = 0; - return 0; - } - - xpc_allow_hb(partid, xpc_vars); - xpc_IPI_send_activated(part); - - - /* - * xpc_partition_up() holds this thread and marks this partition as - * XPC_P_ACTIVE by calling xpc_hb_mark_active(). - */ - (void) xpc_partition_up(part); - - xpc_disallow_hb(partid, xpc_vars); - xpc_mark_partition_inactive(part); - - if (part->reason == xpcReactivating) { - /* interrupting ourselves results in activating partition */ - xpc_IPI_send_reactivate(part); - } - - return 0; -} - - -void -xpc_activate_partition(struct xpc_partition *part) -{ - partid_t partid = XPC_PARTID(part); - unsigned long irq_flags; - pid_t pid; - - - spin_lock_irqsave(&part->act_lock, irq_flags); - - DBUG_ON(part->act_state != XPC_P_INACTIVE); - - part->act_state = XPC_P_ACTIVATION_REQ; - XPC_SET_REASON(part, xpcCloneKThread, __LINE__); - - spin_unlock_irqrestore(&part->act_lock, irq_flags); - - pid = kernel_thread(xpc_activating, (void *) ((u64) partid), 0); - - if (unlikely(pid <= 0)) { - spin_lock_irqsave(&part->act_lock, irq_flags); - part->act_state = XPC_P_INACTIVE; - XPC_SET_REASON(part, xpcCloneKThreadFailed, __LINE__); - spin_unlock_irqrestore(&part->act_lock, irq_flags); - } -} - - -/* - * Handle the receipt of a SGI_XPC_NOTIFY IRQ by seeing whether the specified - * partition actually sent it. Since SGI_XPC_NOTIFY IRQs may be shared by more - * than one partition, we use an AMO_t structure per partition to indicate - * whether a partition has sent an IPI or not. >>> If it has, then wake up the - * associated kthread to handle it. - * - * All SGI_XPC_NOTIFY IRQs received by XPC are the result of IPIs sent by XPC - * running on other partitions. - * - * Noteworthy Arguments: - * - * irq - Interrupt ReQuest number. NOT USED. - * - * dev_id - partid of IPI's potential sender. - */ -irqreturn_t -xpc_notify_IRQ_handler(int irq, void *dev_id) -{ - partid_t partid = (partid_t) (u64) dev_id; - struct xpc_partition *part = &xpc_partitions[partid]; - - - DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); - - if (xpc_part_ref(part)) { - xpc_check_for_channel_activity(part); - - xpc_part_deref(part); - } - return IRQ_HANDLED; -} - - -/* - * Check to see if xpc_notify_IRQ_handler() dropped any IPIs on the floor - * because the write to their associated IPI amo completed after the IRQ/IPI - * was received. - */ -void -xpc_dropped_IPI_check(struct xpc_partition *part) -{ - if (xpc_part_ref(part)) { - xpc_check_for_channel_activity(part); - - part->dropped_IPI_timer.expires = jiffies + - XPC_P_DROPPED_IPI_WAIT; - add_timer(&part->dropped_IPI_timer); - xpc_part_deref(part); - } -} - - -void -xpc_activate_kthreads(struct xpc_channel *ch, int needed) -{ - int idle = atomic_read(&ch->kthreads_idle); - int assigned = atomic_read(&ch->kthreads_assigned); - int wakeup; - - - DBUG_ON(needed <= 0); - - if (idle > 0) { - wakeup = (needed > idle) ? idle : needed; - needed -= wakeup; - - dev_dbg(xpc_chan, "wakeup %d idle kthreads, partid=%d, " - "channel=%d\n", wakeup, ch->partid, ch->number); - - /* only wakeup the requested number of kthreads */ - wake_up_nr(&ch->idle_wq, wakeup); - } - - if (needed <= 0) { - return; - } - - if (needed + assigned > ch->kthreads_assigned_limit) { - needed = ch->kthreads_assigned_limit - assigned; - // >>>should never be less than 0 - if (needed <= 0) { - return; - } - } - - dev_dbg(xpc_chan, "create %d new kthreads, partid=%d, channel=%d\n", - needed, ch->partid, ch->number); - - xpc_create_kthreads(ch, needed, 0); -} - - -/* - * This function is where XPC's kthreads wait for messages to deliver. - */ -static void -xpc_kthread_waitmsgs(struct xpc_partition *part, struct xpc_channel *ch) -{ - do { - /* deliver messages to their intended recipients */ - - while ((volatile s64) ch->w_local_GP.get < - (volatile s64) ch->w_remote_GP.put && - !((volatile u32) ch->flags & - XPC_C_DISCONNECTING)) { - xpc_deliver_msg(ch); - } - - if (atomic_inc_return(&ch->kthreads_idle) > - ch->kthreads_idle_limit) { - /* too many idle kthreads on this channel */ - atomic_dec(&ch->kthreads_idle); - break; - } - - dev_dbg(xpc_chan, "idle kthread calling " - "wait_event_interruptible_exclusive()\n"); - - (void) wait_event_interruptible_exclusive(ch->idle_wq, - ((volatile s64) ch->w_local_GP.get < - (volatile s64) ch->w_remote_GP.put || - ((volatile u32) ch->flags & - XPC_C_DISCONNECTING))); - - atomic_dec(&ch->kthreads_idle); - - } while (!((volatile u32) ch->flags & XPC_C_DISCONNECTING)); -} - - -static int -xpc_daemonize_kthread(void *args) -{ - partid_t partid = XPC_UNPACK_ARG1(args); - u16 ch_number = XPC_UNPACK_ARG2(args); - 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); - - dev_dbg(xpc_chan, "kthread starting, partid=%d, channel=%d\n", - partid, ch_number); - - ch = &part->channels[ch_number]; - - if (!(ch->flags & XPC_C_DISCONNECTING)) { - - /* let registerer know that connection has been established */ - - spin_lock_irqsave(&ch->lock, irq_flags); - if (!(ch->flags & XPC_C_CONNECTEDCALLOUT)) { - ch->flags |= XPC_C_CONNECTEDCALLOUT; - spin_unlock_irqrestore(&ch->lock, irq_flags); - - xpc_connected_callout(ch); - - spin_lock_irqsave(&ch->lock, irq_flags); - ch->flags |= XPC_C_CONNECTEDCALLOUT_MADE; - spin_unlock_irqrestore(&ch->lock, irq_flags); - - /* - * It is possible that while the callout was being - * made that the remote partition sent some messages. - * If that is the case, we may need to activate - * additional kthreads to help deliver them. We only - * need one less than total #of messages to deliver. - */ - n_needed = ch->w_remote_GP.put - ch->w_local_GP.get - 1; - if (n_needed > 0 && - !(ch->flags & XPC_C_DISCONNECTING)) { - xpc_activate_kthreads(ch, n_needed); - } - } else { - spin_unlock_irqrestore(&ch->lock, irq_flags); - } - - xpc_kthread_waitmsgs(part, ch); - } - - /* let registerer know that connection is disconnecting */ - - spin_lock_irqsave(&ch->lock, irq_flags); - if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) && - !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) { - ch->flags |= XPC_C_DISCONNECTINGCALLOUT; - spin_unlock_irqrestore(&ch->lock, irq_flags); - - xpc_disconnect_callout(ch, xpcDisconnecting); - - spin_lock_irqsave(&ch->lock, irq_flags); - ch->flags |= XPC_C_DISCONNECTINGCALLOUT_MADE; - } - spin_unlock_irqrestore(&ch->lock, irq_flags); - - if (atomic_dec_return(&ch->kthreads_assigned) == 0) { - if (atomic_dec_return(&part->nchannels_engaged) == 0) { - xpc_mark_partition_disengaged(part); - xpc_IPI_send_disengage(part); - } - } - - xpc_msgqueue_deref(ch); - - dev_dbg(xpc_chan, "kthread exiting, partid=%d, channel=%d\n", - partid, ch_number); - - xpc_part_deref(part); - return 0; -} - - -/* - * For each partition that XPC has established communications with, there is - * a minimum of one kernel thread assigned to perform any operation that - * may potentially sleep or block (basically the callouts to the asynchronous - * functions registered via xpc_connect()). - * - * Additional kthreads are created and destroyed by XPC as the workload - * demands. - * - * A kthread is assigned to one of the active channels that exists for a given - * partition. - */ -void -xpc_create_kthreads(struct xpc_channel *ch, int needed, - int ignore_disconnecting) -{ - 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) { - - /* - * 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. - */ - if (ignore_disconnecting) { - if (!atomic_inc_not_zero(&ch->kthreads_assigned)) { - /* kthreads assigned had gone to zero */ - BUG_ON(!(ch->flags & - XPC_C_DISCONNECTINGCALLOUT_MADE)); - break; - } - - } else if (ch->flags & XPC_C_DISCONNECTING) { - break; - - } else if (atomic_inc_return(&ch->kthreads_assigned) == 1) { - if (atomic_inc_return(&part->nchannels_engaged) == 1) - xpc_mark_partition_engaged(part); - } - (void) xpc_part_ref(part); - xpc_msgqueue_ref(ch); - - pid = kernel_thread(xpc_daemonize_kthread, (void *) args, 0); - if (pid < 0) { - /* the fork failed */ - - /* - * NOTE: if (ignore_disconnecting && - * !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) is true, - * then we'll deadlock if all other kthreads assigned - * to this channel are blocked in the channel's - * registerer, because the only thing that will unblock - * them is the xpcDisconnecting callout that this - * failed kernel_thread would have made. - */ - - 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) { - /* - * Flag this as an error only if we have an - * insufficient #of kthreads for the channel - * to function. - */ - spin_lock_irqsave(&ch->lock, irq_flags); - XPC_DISCONNECT_CHANNEL(ch, xpcLackOfResources, - &irq_flags); - spin_unlock_irqrestore(&ch->lock, irq_flags); - } - break; - } - - ch->kthreads_created++; // >>> temporary debug only!!! - } -} - - -void -xpc_disconnect_wait(int ch_number) -{ - unsigned long irq_flags; - 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)) { - continue; - } - - ch = &part->channels[ch_number]; - - if (!(ch->flags & XPC_C_WDISCONNECT)) { - xpc_part_deref(part); - continue; - } - - wait_for_completion(&ch->wdisconnect_wait); - - 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); - } -} - - -static void -xpc_do_exit(enum xpc_retval reason) -{ - partid_t partid; - int active_part_count, printed_waiting_msg = 0; - struct xpc_partition *part; - unsigned long printmsg_time, disengage_request_timeout = 0; - - - /* a 'rmmod XPC' and a 'reboot' cannot both end up here together */ - DBUG_ON(xpc_exiting == 1); - - /* - * 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); - - /* ignore all incoming interrupts */ - free_irq(SGI_XPC_ACTIVATE, NULL); - - /* wait for the discovery thread to exit */ - wait_for_completion(&xpc_discovery_exited); - - /* wait for the heartbeat checker thread to exit */ - wait_for_completion(&xpc_hb_checker_exited); - - - /* sleep for a 1/3 of a second or so */ - (void) msleep_interruptible(300); - - - /* wait for all partitions to become inactive */ - - printmsg_time = jiffies + (XPC_DISENGAGE_PRINTMSG_INTERVAL * HZ); - xpc_disengage_request_timedout = 0; - - do { - active_part_count = 0; - - for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) { - part = &xpc_partitions[partid]; - - if (xpc_partition_disengaged(part) && - part->act_state == XPC_P_INACTIVE) { - continue; - } - - active_part_count++; - - XPC_DEACTIVATE_PARTITION(part, reason); - - if (part->disengage_request_timeout > - disengage_request_timeout) { - disengage_request_timeout = - part->disengage_request_timeout; - } - } - - if (xpc_partition_engaged(-1UL)) { - if (time_after(jiffies, printmsg_time)) { - dev_info(xpc_part, "waiting for remote " - "partitions to disengage, timeout in " - "%ld seconds\n", - (disengage_request_timeout - jiffies) - / HZ); - printmsg_time = jiffies + - (XPC_DISENGAGE_PRINTMSG_INTERVAL * HZ); - printed_waiting_msg = 1; - } - - } else if (active_part_count > 0) { - if (printed_waiting_msg) { - dev_info(xpc_part, "waiting for local partition" - " to disengage\n"); - printed_waiting_msg = 0; - } - - } else { - if (!xpc_disengage_request_timedout) { - dev_info(xpc_part, "all partitions have " - "disengaged\n"); - } - break; - } - - /* 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); - - if (reason == xpcUnloading) { - /* take ourselves off of the reboot_notifier_list */ - (void) unregister_reboot_notifier(&xpc_reboot_notifier); - - /* take ourselves off of the die_notifier list */ - (void) unregister_die_notifier(&xpc_die_notifier); - } - - /* close down protections for IPI operations */ - xpc_restrict_IPI_ops(); - - - /* clear the interface to XPC's functions */ - xpc_clear_interface(); - - if (xpc_sysctl) { - unregister_sysctl_table(xpc_sysctl); - } - - kfree(xpc_remote_copy_buffer_base); -} - - -/* - * 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; -} - - -/* - * Notify other partitions to disengage from all references to our memory. - */ -static void -xpc_die_disengage(void) -{ - struct xpc_partition *part; - partid_t partid; - unsigned long engaged; - long time, printmsg_time, disengage_request_timeout; - - - /* keep xpc_hb_checker thread from doing anything (just in case) */ - xpc_exiting = 1; - - xpc_vars->heartbeating_to_mask = 0; /* indicate we're deactivated */ - - for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) { - part = &xpc_partitions[partid]; - - if (!XPC_SUPPORTS_DISENGAGE_REQUEST(part-> - remote_vars_version)) { - - /* just in case it was left set by an earlier XPC */ - xpc_clear_partition_engaged(1UL << partid); - continue; - } - - if (xpc_partition_engaged(1UL << partid) || - part->act_state != XPC_P_INACTIVE) { - xpc_request_partition_disengage(part); - xpc_mark_partition_disengaged(part); - xpc_IPI_send_disengage(part); - } - } - - time = rtc_time(); - printmsg_time = time + - (XPC_DISENGAGE_PRINTMSG_INTERVAL * sn_rtc_cycles_per_second); - disengage_request_timeout = time + - (xpc_disengage_request_timelimit * sn_rtc_cycles_per_second); - - /* wait for all other partitions to disengage from us */ - - while (1) { - engaged = xpc_partition_engaged(-1UL); - if (!engaged) { - dev_info(xpc_part, "all partitions have disengaged\n"); - break; - } - - time = rtc_time(); - if (time >= disengage_request_timeout) { - for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) { - if (engaged & (1UL << partid)) { - dev_info(xpc_part, "disengage from " - "remote partition %d timed " - "out\n", partid); - } - } - break; - } - - if (time >= printmsg_time) { - dev_info(xpc_part, "waiting for remote partitions to " - "disengage, timeout in %ld seconds\n", - (disengage_request_timeout - time) / - sn_rtc_cycles_per_second); - printmsg_time = time + - (XPC_DISENGAGE_PRINTMSG_INTERVAL * - sn_rtc_cycles_per_second); - } - } -} - - -/* - * This function is called when the system is being restarted or halted due - * to some sort of system failure. If this is the case we need to notify the - * other partitions to disengage from all references to our memory. - * This function can also be called when our heartbeater could be offlined - * for a time. In this case we need to notify other partitions to not worry - * about the lack of a heartbeat. - */ -static int -xpc_system_die(struct notifier_block *nb, unsigned long event, void *unused) -{ - switch (event) { - case DIE_MACHINE_RESTART: - case DIE_MACHINE_HALT: - xpc_die_disengage(); - break; - - case DIE_KDEBUG_ENTER: - /* Should lack of heartbeat be ignored by other partitions? */ - if (!xpc_kdebug_ignore) { - break; - } - /* fall through */ - case DIE_MCA_MONARCH_ENTER: - case DIE_INIT_MONARCH_ENTER: - xpc_vars->heartbeat++; - xpc_vars->heartbeat_offline = 1; - break; - - case DIE_KDEBUG_LEAVE: - /* Is lack of heartbeat being ignored by other partitions? */ - if (!xpc_kdebug_ignore) { - break; - } - /* fall through */ - case DIE_MCA_MONARCH_LEAVE: - case DIE_INIT_MONARCH_LEAVE: - xpc_vars->heartbeat++; - xpc_vars->heartbeat_offline = 0; - break; - } - - return NOTIFY_DONE; -} - - -int __init -xpc_init(void) -{ - int ret; - partid_t partid; - struct xpc_partition *part; - pid_t pid; - size_t buf_size; - - - if (!ia64_platform_is("sn2")) { - return -ENODEV; - } - - - buf_size = max(XPC_RP_VARS_SIZE, - XPC_RP_HEADER_SIZE + XP_NASID_MASK_BYTES); - xpc_remote_copy_buffer = xpc_kmalloc_cacheline_aligned(buf_size, - GFP_KERNEL, &xpc_remote_copy_buffer_base); - if (xpc_remote_copy_buffer == NULL) - return -ENOMEM; - - snprintf(xpc_part->bus_id, BUS_ID_SIZE, "part"); - snprintf(xpc_chan->bus_id, BUS_ID_SIZE, "chan"); - - xpc_sysctl = register_sysctl_table(xpc_sys_dir); - - /* - * The first few fields of each entry of xpc_partitions[] need to - * be initialized now so that calls to xpc_connect() and - * xpc_disconnect() can be made prior to the activation of any remote - * partition. NOTE THAT NONE OF THE OTHER FIELDS BELONGING TO THESE - * ENTRIES ARE MEANINGFUL UNTIL AFTER AN ENTRY'S CORRESPONDING - * PARTITION HAS BEEN ACTIVATED. - */ - for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) { - part = &xpc_partitions[partid]; - - DBUG_ON((u64) part != L1_CACHE_ALIGN((u64) part)); - - part->act_IRQ_rcvd = 0; - 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); - } - - /* - * Open up protections for IPI operations (and AMO operations on - * Shub 1.1 systems). - */ - xpc_allow_IPI_ops(); - - /* - * Interrupts being processed will increment this atomic variable and - * awaken the heartbeat thread which will process the interrupts. - */ - atomic_set(&xpc_act_IRQ_rcvd, 0); - - /* - * This is safe to do before the xpc_hb_checker thread has started - * because the handler releases a wait queue. If an interrupt is - * received before the thread is waiting, it will not go to sleep, - * but rather immediately process the interrupt. - */ - ret = request_irq(SGI_XPC_ACTIVATE, xpc_act_IRQ_handler, 0, - "xpc hb", NULL); - if (ret != 0) { - dev_err(xpc_part, "can't register ACTIVATE IRQ handler, " - "errno=%d\n", -ret); - - xpc_restrict_IPI_ops(); - - if (xpc_sysctl) { - unregister_sysctl_table(xpc_sysctl); - } - - kfree(xpc_remote_copy_buffer_base); - return -EBUSY; - } - - /* - * Fill the partition reserved page with the information needed by - * other partitions to discover we are alive and establish initial - * communications. - */ - xpc_rsvd_page = xpc_rsvd_page_init(); - if (xpc_rsvd_page == NULL) { - dev_err(xpc_part, "could not setup our reserved page\n"); - - free_irq(SGI_XPC_ACTIVATE, NULL); - xpc_restrict_IPI_ops(); - - if (xpc_sysctl) { - unregister_sysctl_table(xpc_sysctl); - } - - kfree(xpc_remote_copy_buffer_base); - return -EBUSY; - } - - - /* 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"); - } - - /* add ourselves to the die_notifier list */ - ret = register_die_notifier(&xpc_die_notifier); - if (ret != 0) { - dev_warn(xpc_part, "can't register die notifier\n"); - } - - init_timer(&xpc_hb_timer); - xpc_hb_timer.function = xpc_hb_beater; - - /* - * The real work-horse behind xpc. This processes incoming - * interrupts and monitors remote heartbeats. - */ - pid = kernel_thread(xpc_hb_checker, NULL, 0); - if (pid < 0) { - dev_err(xpc_part, "failed while forking hb check thread\n"); - - /* 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); - - /* take ourselves off of the die_notifier list */ - (void) unregister_die_notifier(&xpc_die_notifier); - - del_timer_sync(&xpc_hb_timer); - free_irq(SGI_XPC_ACTIVATE, NULL); - xpc_restrict_IPI_ops(); - - if (xpc_sysctl) { - unregister_sysctl_table(xpc_sysctl); - } - - kfree(xpc_remote_copy_buffer_base); - return -EBUSY; - } - - - /* - * Startup a thread that will attempt to discover other partitions to - * activate based on info provided by SAL. This new thread is short - * lived and will exit once discovery is complete. - */ - pid = kernel_thread(xpc_initiate_discovery, NULL, 0); - if (pid < 0) { - dev_err(xpc_part, "failed while forking discovery thread\n"); - - /* mark this new thread as a non-starter */ - complete(&xpc_discovery_exited); - - xpc_do_exit(xpcUnloading); - return -EBUSY; - } - - - /* set the interface to point at XPC's functions */ - xpc_set_interface(xpc_initiate_connect, xpc_initiate_disconnect, - xpc_initiate_allocate, xpc_initiate_send, - xpc_initiate_send_notify, xpc_initiate_received, - xpc_initiate_partid_to_nasids); - - return 0; -} -module_init(xpc_init); - - -void __exit -xpc_exit(void) -{ - xpc_do_exit(xpcUnloading); -} -module_exit(xpc_exit); - - -MODULE_AUTHOR("Silicon Graphics, Inc."); -MODULE_DESCRIPTION("Cross Partition Communication (XPC) support"); -MODULE_LICENSE("GPL"); - -module_param(xpc_hb_interval, int, 0); -MODULE_PARM_DESC(xpc_hb_interval, "Number of seconds between " - "heartbeat increments."); - -module_param(xpc_hb_check_interval, int, 0); -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."); - -module_param(xpc_kdebug_ignore, int, 0); -MODULE_PARM_DESC(xpc_kdebug_ignore, "Should lack of heartbeat be ignored by " - "other partitions when dropping into kdebug."); - |