[IA64-SGI] sn2 mutex conversion

Migrate sn2 code to use mutex and completion events rather than
semaphores.

Signed-off-by: Jes Sorensen <jes@sgi.com>
Acked-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

4 files changed, 36 insertions, 39 deletions

diff --git a/arch/ia64/sn/kernel/mca.c b/arch/ia64/sn/kernel/mca.c
index 6546db6abdba..9ab684d1bb55 100644
--- a/arch/ia64/sn/kernel/mca.c
+++ b/arch/ia64/sn/kernel/mca.c
@@ -10,6 +10,7 @@
 #include <linux/kernel.h>
 #include <linux/timer.h>
 #include <linux/vmalloc.h>
+#include <linux/mutex.h>
 #include <asm/mca.h>
 #include <asm/sal.h>
 #include <asm/sn/sn_sal.h>
@@ -27,7 +28,7 @@ void sn_init_cpei_timer(void);
 /* Printing oemdata from mca uses data that is not passed through SAL, it is
  * global.  Only one user at a time.
  */
-static DECLARE_MUTEX(sn_oemdata_mutex);
+static DEFINE_MUTEX(sn_oemdata_mutex);
 static u8 **sn_oemdata;
 static u64 *sn_oemdata_size, sn_oemdata_bufsize;
 
@@ -89,7 +90,7 @@ static int
 sn_platform_plat_specific_err_print(const u8 * sect_header, u8 ** oemdata,
                                     u64 * oemdata_size)
 {
-        down(&sn_oemdata_mutex);
+        mutex_lock(&sn_oemdata_mutex);
         sn_oemdata = oemdata;
         sn_oemdata_size = oemdata_size;
         sn_oemdata_bufsize = 0;
@@ -107,7 +108,7 @@ sn_platform_plat_specific_err_print(const u8 * sect_header, u8 ** oemdata,
                 *sn_oemdata_size = 0;
                 ia64_sn_plat_specific_err_print(print_hook, (char *)sect_header);
         }
-        up(&sn_oemdata_mutex);
+        mutex_unlock(&sn_oemdata_mutex);
         return 0;
 }
 
diff --git a/arch/ia64/sn/kernel/xp_main.c b/arch/ia64/sn/kernel/xp_main.c
index 3be52a34c80f..b7ea46645e12 100644
--- a/arch/ia64/sn/kernel/xp_main.c
+++ b/arch/ia64/sn/kernel/xp_main.c
@@ -19,6 +19,7 @@
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <asm/sn/intr.h>
 #include <asm/sn/sn_sal.h>
 #include <asm/sn/xp.h>
@@ -136,13 +137,13 @@ xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
 
         registration = &xpc_registrations[ch_number];
 
-        if (down_interruptible(&registration->sema) != 0) {
+        if (mutex_lock_interruptible(&registration->mutex) != 0) {
                 return xpcInterrupted;
         }
 
         /* if XPC_CHANNEL_REGISTERED(ch_number) */
         if (registration->func != NULL) {
-                up(&registration->sema);
+                mutex_unlock(&registration->mutex);
                 return xpcAlreadyRegistered;
         }
 
@@ -154,7 +155,7 @@ xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
         registration->key = key;
         registration->func = func;
 
-        up(&registration->sema);
+        mutex_unlock(&registration->mutex);
 
         xpc_interface.connect(ch_number);
 
@@ -190,11 +191,11 @@ xpc_disconnect(int ch_number)
          * figured XPC's users will just turn around and call xpc_disconnect()
          * again anyways, so we might as well wait, if need be.
          */
-        down(&registration->sema);
+        mutex_lock(&registration->mutex);
 
         /* if !XPC_CHANNEL_REGISTERED(ch_number) */
         if (registration->func == NULL) {
-                up(&registration->sema);
+                mutex_unlock(&registration->mutex);
                 return;
         }
 
@@ -208,7 +209,7 @@ xpc_disconnect(int ch_number)
 
         xpc_interface.disconnect(ch_number);
 
-        up(&registration->sema);
+        mutex_unlock(&registration->mutex);
 
         return;
 }
@@ -250,9 +251,9 @@ xp_init(void)
                 xp_nofault_PIOR_target = SH1_IPI_ACCESS;
         }
 
-        /* initialize the connection registration semaphores */
+        /* initialize the connection registration mutex */
         for (ch_number = 0; ch_number < XPC_NCHANNELS; ch_number++) {
-                sema_init(&xpc_registrations[ch_number].sema, 1);  /* mutex */
+                mutex_init(&xpc_registrations[ch_number].mutex);
         }
 
         return 0;
diff --git a/arch/ia64/sn/kernel/xpc_channel.c b/arch/ia64/sn/kernel/xpc_channel.c
index 0c0a68902409..8d950c778bb6 100644
--- a/arch/ia64/sn/kernel/xpc_channel.c
+++ b/arch/ia64/sn/kernel/xpc_channel.c
@@ -22,6 +22,8 @@
 #include <linux/cache.h>
 #include <linux/interrupt.h>
 #include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/completion.h>
 #include <asm/sn/bte.h>
 #include <asm/sn/sn_sal.h>
 #include <asm/sn/xpc.h>
@@ -56,8 +58,8 @@ xpc_initialize_channels(struct xpc_partition *part, partid_t partid)
                 atomic_set(&ch->n_to_notify, 0);
 
                 spin_lock_init(&ch->lock);
-                sema_init(&ch->msg_to_pull_sema, 1);    /* mutex */
-                sema_init(&ch->wdisconnect_sema, 0);    /* event wait */
+                mutex_init(&ch->msg_to_pull_mutex);
+                init_completion(&ch->wdisconnect_wait);
 
                 atomic_set(&ch->n_on_msg_allocate_wq, 0);
                 init_waitqueue_head(&ch->msg_allocate_wq);
@@ -534,7 +536,6 @@ static enum xpc_retval
 xpc_allocate_msgqueues(struct xpc_channel *ch)
 {
         unsigned long irq_flags;
-        int i;
         enum xpc_retval ret;
 
 
@@ -552,11 +553,6 @@ xpc_allocate_msgqueues(struct xpc_channel *ch)
                 return ret;
         }
 
-        for (i = 0; i < ch->local_nentries; i++) {
-                /* use a semaphore as an event wait queue */
-                sema_init(&ch->notify_queue[i].sema, 0);
-        }
-
         spin_lock_irqsave(&ch->lock, irq_flags);
         ch->flags |= XPC_C_SETUP;
         spin_unlock_irqrestore(&ch->lock, irq_flags);
@@ -799,10 +795,8 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
         }
 
         if (ch->flags & XPC_C_WDISCONNECT) {
-                spin_unlock_irqrestore(&ch->lock, *irq_flags);
-                up(&ch->wdisconnect_sema);
-                spin_lock_irqsave(&ch->lock, *irq_flags);
-
+                /* we won't lose the CPU since we're holding ch->lock */
+                complete(&ch->wdisconnect_wait);
         } else if (ch->delayed_IPI_flags) {
                 if (part->act_state != XPC_P_DEACTIVATING) {
                         /* time to take action on any delayed IPI flags */
@@ -1092,12 +1086,12 @@ xpc_connect_channel(struct xpc_channel *ch)
         struct xpc_registration *registration = &xpc_registrations[ch->number];
 
 
-        if (down_trylock(&registration->sema) != 0) {
+        if (mutex_trylock(&registration->mutex) == 0) {
                 return xpcRetry;
         }
 
         if (!XPC_CHANNEL_REGISTERED(ch->number)) {
-                up(&registration->sema);
+                mutex_unlock(&registration->mutex);
                 return xpcUnregistered;
         }
 
@@ -1108,7 +1102,7 @@ xpc_connect_channel(struct xpc_channel *ch)
 
         if (ch->flags & XPC_C_DISCONNECTING) {
                 spin_unlock_irqrestore(&ch->lock, irq_flags);
-                up(&registration->sema);
+                mutex_unlock(&registration->mutex);
                 return ch->reason;
         }
 
@@ -1140,7 +1134,7 @@ xpc_connect_channel(struct xpc_channel *ch)
                          * channel lock be locked and will unlock and relock
                          * the channel lock as needed.
                          */
-                        up(&registration->sema);
+                        mutex_unlock(&registration->mutex);
                         XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes,
                                                                 &irq_flags);
                         spin_unlock_irqrestore(&ch->lock, irq_flags);
@@ -1155,7 +1149,7 @@ xpc_connect_channel(struct xpc_channel *ch)
                 atomic_inc(&xpc_partitions[ch->partid].nchannels_active);
         }
 
-        up(&registration->sema);
+        mutex_unlock(&registration->mutex);
 
 
         /* initiate the connection */
@@ -2089,7 +2083,7 @@ xpc_pull_remote_msg(struct xpc_channel *ch, s64 get)
         enum xpc_retval ret;
 
 
-        if (down_interruptible(&ch->msg_to_pull_sema) != 0) {
+        if (mutex_lock_interruptible(&ch->msg_to_pull_mutex) != 0) {
                 /* we were interrupted by a signal */
                 return NULL;
         }
@@ -2125,7 +2119,7 @@ xpc_pull_remote_msg(struct xpc_channel *ch, s64 get)
 
                         XPC_DEACTIVATE_PARTITION(part, ret);
 
-                        up(&ch->msg_to_pull_sema);
+                        mutex_unlock(&ch->msg_to_pull_mutex);
                         return NULL;
                 }
 
@@ -2134,7 +2128,7 @@ xpc_pull_remote_msg(struct xpc_channel *ch, s64 get)
                 ch->next_msg_to_pull += nmsgs;
         }
 
-        up(&ch->msg_to_pull_sema);
+        mutex_unlock(&ch->msg_to_pull_mutex);
 
         /* return the message we were looking for */
         msg_offset = (get % ch->remote_nentries) * ch->msg_size;
diff --git a/arch/ia64/sn/kernel/xpc_main.c b/arch/ia64/sn/kernel/xpc_main.c
index 8930586e0eb4..c75f8aeefc2b 100644
--- a/arch/ia64/sn/kernel/xpc_main.c
+++ b/arch/ia64/sn/kernel/xpc_main.c
@@ -55,6 +55,7 @@
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/reboot.h>
+#include <linux/completion.h>
 #include <asm/sn/intr.h>
 #include <asm/sn/sn_sal.h>
 #include <asm/kdebug.h>
@@ -177,10 +178,10 @@ 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_MUTEX_LOCKED(xpc_hb_checker_exited);
+static DECLARE_COMPLETION(xpc_hb_checker_exited);
 
 /* notification that the xpc_discovery thread has exited */
-static DECLARE_MUTEX_LOCKED(xpc_discovery_exited);
+static DECLARE_COMPLETION(xpc_discovery_exited);
 
 
 static struct timer_list xpc_hb_timer;
@@ -321,7 +322,7 @@ xpc_hb_checker(void *ignore)
 
 
         /* mark this thread as having exited */
-        up(&xpc_hb_checker_exited);
+        complete(&xpc_hb_checker_exited);
         return 0;
 }
 
@@ -341,7 +342,7 @@ xpc_initiate_discovery(void *ignore)
         dev_dbg(xpc_part, "discovery thread is exiting\n");
 
         /* mark this thread as having exited */
-        up(&xpc_discovery_exited);
+        complete(&xpc_discovery_exited);
         return 0;
 }
 
@@ -893,7 +894,7 @@ xpc_disconnect_wait(int ch_number)
                         continue;
                 }
 
-                (void) down(&ch->wdisconnect_sema);
+                wait_for_completion(&ch->wdisconnect_wait);
 
                 spin_lock_irqsave(&ch->lock, irq_flags);
                 DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED));
@@ -946,10 +947,10 @@ xpc_do_exit(enum xpc_retval reason)
         free_irq(SGI_XPC_ACTIVATE, NULL);
 
         /* wait for the discovery thread to exit */
-        down(&xpc_discovery_exited);
+        wait_for_completion(&xpc_discovery_exited);
 
         /* wait for the heartbeat checker thread to exit */
-        down(&xpc_hb_checker_exited);
+        wait_for_completion(&xpc_hb_checker_exited);
 
 
         /* sleep for a 1/3 of a second or so */
@@ -1367,7 +1368,7 @@ 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);
+                complete(&xpc_discovery_exited);
 
                 xpc_do_exit(xpcUnloading);
                 return -EBUSY;