1 files changed, 56 insertions, 111 deletions

diff --git a/drivers/misc/sgi-xp/xpc_main.c b/drivers/misc/sgi-xp/xpc_main.c
index d81a2dd787ac..f673ba90eb0e 100644
--- a/drivers/misc/sgi-xp/xpc_main.c
+++ b/drivers/misc/sgi-xp/xpc_main.c
@@ -46,17 +46,16 @@
 #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 <linux/kthread.h>
+#include <linux/uaccess.h>
 #include <asm/sn/intr.h>
 #include <asm/sn/sn_sal.h>
-#include <asm/uaccess.h>
 #include "xpc.h"
 
 /* define two XPC debug device structures to be used with dev_dbg() et al */
@@ -91,7 +90,7 @@ 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_min_timelimit; /* = 0 */
 static int xpc_disengage_request_max_timelimit = 120;
 
 static ctl_table xpc_sys_xpc_hb_dir[] = {
@@ -213,9 +212,8 @@ xpc_hb_beater(unsigned long dummy)
 {
         xpc_vars->heartbeat++;
 
-        if (time_after_eq(jiffies, xpc_hb_check_timeout)) {
+        if (time_after_eq(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);
@@ -234,15 +232,13 @@ xpc_hb_checker(void *ignore)
 
         /* 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) {
+        while (!xpc_exiting) {
 
                 dev_dbg(xpc_part, "woke up with %d ticks rem; %d IRQs have "
                         "been received\n",
@@ -287,7 +283,7 @@ xpc_hb_checker(void *ignore)
                                                 atomic_read(&xpc_act_IRQ_rcvd)
                                                 || time_after_eq(jiffies,
                                                         xpc_hb_check_timeout) ||
-                                                (volatile int)xpc_exiting));
+                                                xpc_exiting));
         }
 
         dev_dbg(xpc_part, "heartbeat checker is exiting\n");
@@ -305,8 +301,6 @@ xpc_hb_checker(void *ignore)
 static int
 xpc_initiate_discovery(void *ignore)
 {
-        daemonize(XPC_DISCOVERY_THREAD_NAME);
-
         xpc_discovery();
 
         dev_dbg(xpc_part, "discovery thread is exiting\n");
@@ -338,9 +332,8 @@ xpc_make_first_contact(struct xpc_partition *part)
                 /* wait a 1/4 of a second or so */
                 (void)msleep_interruptible(250);
 
-                if (part->act_state == XPC_P_DEACTIVATING) {
+                if (part->act_state == XPC_P_DEACTIVATING)
                         return part->reason;
-                }
         }
 
         return xpc_mark_partition_active(part);
@@ -382,22 +375,12 @@ xpc_channel_mgr(struct xpc_partition *part)
                  */
                 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_read(&part->channel_mgr_requests) > 0 ||
+                                 part->local_IPI_amo != 0 ||
+                                 (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?
         }
 }
 
@@ -423,9 +406,8 @@ xpc_partition_up(struct xpc_partition *part)
 
         dev_dbg(xpc_chan, "activating partition %d\n", XPC_PARTID(part));
 
-        if (xpc_setup_infrastructure(part) != xpcSuccess) {
+        if (xpc_setup_infrastructure(part) != xpcSuccess)
                 return;
-        }
 
         /*
          * The kthread that XPC HB called us with will become the
@@ -436,9 +418,8 @@ xpc_partition_up(struct xpc_partition *part)
 
         (void)xpc_part_ref(part);       /* this will always succeed */
 
-        if (xpc_make_first_contact(part) == xpcSuccess) {
+        if (xpc_make_first_contact(part) == xpcSuccess)
                 xpc_channel_mgr(part);
-        }
 
         xpc_part_deref(part);
 
@@ -451,8 +432,6 @@ 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);
 
@@ -474,21 +453,6 @@ xpc_activating(void *__partid)
 
         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, &param);
-        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
@@ -537,7 +501,7 @@ xpc_activate_partition(struct xpc_partition *part)
 {
         partid_t partid = XPC_PARTID(part);
         unsigned long irq_flags;
-        pid_t pid;
+        struct task_struct *kthread;
 
         spin_lock_irqsave(&part->act_lock, irq_flags);
 
@@ -548,9 +512,9 @@ xpc_activate_partition(struct xpc_partition *part)
 
         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 
-        pid = kernel_thread(xpc_activating, (void *)((u64)partid), 0);
-
-        if (unlikely(pid <= 0)) {
+        kthread = kthread_run(xpc_activating, (void *)((u64)partid), "xpc%02d",
+                              partid);
+        if (IS_ERR(kthread)) {
                 spin_lock_irqsave(&part->act_lock, irq_flags);
                 part->act_state = XPC_P_INACTIVE;
                 XPC_SET_REASON(part, xpcCloneKThreadFailed, __LINE__);
@@ -562,7 +526,7 @@ xpc_activate_partition(struct xpc_partition *part)
  * 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
+ * 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
@@ -628,16 +592,13 @@ xpc_activate_kthreads(struct xpc_channel *ch, int needed)
                 wake_up_nr(&ch->idle_wq, wakeup);
         }
 
-        if (needed <= 0) {
+        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) {
+                if (needed <= 0)
                         return;
-                }
         }
 
         dev_dbg(xpc_chan, "create %d new kthreads, partid=%d, channel=%d\n",
@@ -655,9 +616,8 @@ 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)) {
+                while (ch->w_local_GP.get < ch->w_remote_GP.put &&
+                       !(ch->flags & XPC_C_DISCONNECTING)) {
                         xpc_deliver_msg(ch);
                 }
 
@@ -672,21 +632,16 @@ xpc_kthread_waitmsgs(struct xpc_partition *part, struct xpc_channel *ch)
                         "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)));
+                                (ch->w_local_GP.get < ch->w_remote_GP.put ||
+                                 (ch->flags & XPC_C_DISCONNECTING)));
 
                 atomic_dec(&ch->kthreads_idle);
 
-        } while (!((volatile u32)ch->flags & XPC_C_DISCONNECTING));
+        } while (!(ch->flags & XPC_C_DISCONNECTING));
 }
 
 static int
-xpc_daemonize_kthread(void *args)
+xpc_kthread_start(void *args)
 {
         partid_t partid = XPC_UNPACK_ARG1(args);
         u16 ch_number = XPC_UNPACK_ARG2(args);
@@ -695,8 +650,6 @@ xpc_daemonize_kthread(void *args)
         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);
 
@@ -725,9 +678,9 @@ xpc_daemonize_kthread(void *args)
                          * 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)) {
+                        if (n_needed > 0 && !(ch->flags & XPC_C_DISCONNECTING))
                                 xpc_activate_kthreads(ch, n_needed);
-                        }
+
                 } else {
                         spin_unlock_irqrestore(&ch->lock, irq_flags);
                 }
@@ -783,9 +736,9 @@ 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];
+        struct task_struct *kthread;
 
         while (needed-- > 0) {
 
@@ -812,8 +765,9 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed,
                 (void)xpc_part_ref(part);
                 xpc_msgqueue_ref(ch);
 
-                pid = kernel_thread(xpc_daemonize_kthread, (void *)args, 0);
-                if (pid < 0) {
+                kthread = kthread_run(xpc_kthread_start, (void *)args,
+                                      "xpc%02dc%d", ch->partid, ch->number);
+                if (IS_ERR(kthread)) {
                         /* the fork failed */
 
                         /*
@@ -823,7 +777,7 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed,
                          * 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.
+                         * failed kthread_run() would have made.
                          */
 
                         if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
@@ -848,8 +802,6 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed,
                         }
                         break;
                 }
-
-                ch->kthreads_created++; // >>> temporary debug only!!!
         }
 }
 
@@ -866,9 +818,8 @@ xpc_disconnect_wait(int ch_number)
         for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
                 part = &xpc_partitions[partid];
 
-                if (!xpc_part_ref(part)) {
+                if (!xpc_part_ref(part))
                         continue;
-                }
 
                 ch = &part->channels[ch_number];
 
@@ -898,9 +849,8 @@ xpc_disconnect_wait(int ch_number)
                 ch->flags &= ~XPC_C_WDISCONNECT;
                 spin_unlock_irqrestore(&ch->lock, irq_flags);
 
-                if (wakeup_channel_mgr) {
+                if (wakeup_channel_mgr)
                         xpc_wakeup_channel_mgr(part);
-                }
 
                 xpc_part_deref(part);
         }
@@ -1019,9 +969,8 @@ xpc_do_exit(enum xpc_retval reason)
         /* clear the interface to XPC's functions */
         xpc_clear_interface();
 
-        if (xpc_sysctl) {
+        if (xpc_sysctl)
                 unregister_sysctl_table(xpc_sysctl);
-        }
 
         kfree(xpc_remote_copy_buffer_base);
 }
@@ -1071,7 +1020,8 @@ xpc_die_disengage(void)
         for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
                 part = &xpc_partitions[partid];
 
-                if (!XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
+                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);
@@ -1144,9 +1094,9 @@ xpc_system_die(struct notifier_block *nb, unsigned long event, void *unused)
 
         case DIE_KDEBUG_ENTER:
                 /* Should lack of heartbeat be ignored by other partitions? */
-                if (!xpc_kdebug_ignore) {
+                if (!xpc_kdebug_ignore)
                         break;
-                }
+
                 /* fall through */
         case DIE_MCA_MONARCH_ENTER:
         case DIE_INIT_MONARCH_ENTER:
@@ -1156,9 +1106,9 @@ xpc_system_die(struct notifier_block *nb, unsigned long event, void *unused)
 
         case DIE_KDEBUG_LEAVE:
                 /* Is lack of heartbeat being ignored by other partitions? */
-                if (!xpc_kdebug_ignore) {
+                if (!xpc_kdebug_ignore)
                         break;
-                }
+
                 /* fall through */
         case DIE_MCA_MONARCH_LEAVE:
         case DIE_INIT_MONARCH_LEAVE:
@@ -1176,18 +1126,17 @@ xpc_init(void)
         int ret;
         partid_t partid;
         struct xpc_partition *part;
-        pid_t pid;
+        struct task_struct *kthread;
         size_t buf_size;
 
-        if (!ia64_platform_is("sn2")) {
+        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);
+                                                  &xpc_remote_copy_buffer_base);
         if (xpc_remote_copy_buffer == NULL)
                 return -ENOMEM;
 
@@ -1250,9 +1199,8 @@ xpc_init(void)
 
                 xpc_restrict_IPI_ops();
 
-                if (xpc_sysctl) {
+                if (xpc_sysctl)
                         unregister_sysctl_table(xpc_sysctl);
-                }
 
                 kfree(xpc_remote_copy_buffer_base);
                 return -EBUSY;
@@ -1270,9 +1218,8 @@ xpc_init(void)
                 free_irq(SGI_XPC_ACTIVATE, NULL);
                 xpc_restrict_IPI_ops();
 
-                if (xpc_sysctl) {
+                if (xpc_sysctl)
                         unregister_sysctl_table(xpc_sysctl);
-                }
 
                 kfree(xpc_remote_copy_buffer_base);
                 return -EBUSY;
@@ -1280,15 +1227,13 @@ xpc_init(void)
 
         /* add ourselves to the reboot_notifier_list */
         ret = register_reboot_notifier(&xpc_reboot_notifier);
-        if (ret != 0) {
+        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) {
+        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;
@@ -1297,8 +1242,8 @@ xpc_init(void)
          * 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) {
+        kthread = kthread_run(xpc_hb_checker, NULL, XPC_HB_CHECK_THREAD_NAME);
+        if (IS_ERR(kthread)) {
                 dev_err(xpc_part, "failed while forking hb check thread\n");
 
                 /* indicate to others that our reserved page is uninitialized */
@@ -1314,9 +1259,8 @@ xpc_init(void)
                 free_irq(SGI_XPC_ACTIVATE, NULL);
                 xpc_restrict_IPI_ops();
 
-                if (xpc_sysctl) {
+                if (xpc_sysctl)
                         unregister_sysctl_table(xpc_sysctl);
-                }
 
                 kfree(xpc_remote_copy_buffer_base);
                 return -EBUSY;
@@ -1327,8 +1271,9 @@ xpc_init(void)
          * 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) {
+        kthread = kthread_run(xpc_initiate_discovery, NULL,
+                              XPC_DISCOVERY_THREAD_NAME);
+        if (IS_ERR(kthread)) {
                 dev_err(xpc_part, "failed while forking discovery thread\n");
 
                 /* mark this new thread as a non-starter */