[IA64] run drivers/misc/sgi-xp through scripts/checkpatch.pl

Addressed issues raised by scripts/checkpatch.pl. Removed unnecessary curly
braces. Eliminated uses of volatiles and use of kernel_thread() and daemonize().

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

7 files changed, 268 insertions, 391 deletions

diff --git a/drivers/misc/sgi-xp/xp.h b/drivers/misc/sgi-xp/xp.h
index 87171682664..5515234be86 100644
--- a/drivers/misc/sgi-xp/xp.h
+++ b/drivers/misc/sgi-xp/xp.h
@@ -79,9 +79,9 @@ xp_bte_copy(u64 src, u64 vdst, u64 len, u64 mode, void *notification)
 
 	ret = bte_copy(src, pdst, len, mode, notification);
 	if ((ret != BTE_SUCCESS) && BTE_ERROR_RETRY(ret)) {
-		if (!in_interrupt()) {
+		if (!in_interrupt())
 			cond_resched();
-		}
+
 		ret = bte_copy(src, pdst, len, mode, notification);
 	}
 
@@ -255,7 +255,7 @@ enum xpc_retval {
 				/* 115: BTE end */
 	xpcBteSh2End = xpcBteSh2Start + BTEFAIL_SH2_ALL,
 
-	xpcUnknownReason	/* 116: unknown reason -- must be last in list */
+	xpcUnknownReason	/* 116: unknown reason - must be last in enum */
 };
 
 /*
diff --git a/drivers/misc/sgi-xp/xp_main.c b/drivers/misc/sgi-xp/xp_main.c
index bb9257642fc..1fbf99bae96 100644
--- a/drivers/misc/sgi-xp/xp_main.c
+++ b/drivers/misc/sgi-xp/xp_main.c
@@ -23,15 +23,21 @@
 #include "xp.h"
 
 /*
- * Target of nofault PIO read.
+ * The export of xp_nofault_PIOR needs to happen here since it is defined
+ * in drivers/misc/sgi-xp/xp_nofault.S. The target of the nofault read is
+ * defined here.
  */
+EXPORT_SYMBOL_GPL(xp_nofault_PIOR);
+
 u64 xp_nofault_PIOR_target;
+EXPORT_SYMBOL_GPL(xp_nofault_PIOR_target);
 
 /*
  * xpc_registrations[] keeps track of xpc_connect()'s done by the kernel-level
  * users of XPC.
  */
 struct xpc_registration xpc_registrations[XPC_NCHANNELS];
+EXPORT_SYMBOL_GPL(xpc_registrations);
 
 /*
  * Initialize the XPC interface to indicate that XPC isn't loaded.
@@ -52,6 +58,7 @@ struct xpc_interface xpc_interface = {
 	(void (*)(partid_t, int, void *))xpc_notloaded,
 	(enum xpc_retval(*)(partid_t, void *))xpc_notloaded
 };
+EXPORT_SYMBOL_GPL(xpc_interface);
 
 /*
  * XPC calls this when it (the XPC module) has been loaded.
@@ -74,6 +81,7 @@ xpc_set_interface(void (*connect) (int),
 	xpc_interface.received = received;
 	xpc_interface.partid_to_nasids = partid_to_nasids;
 }
+EXPORT_SYMBOL_GPL(xpc_set_interface);
 
 /*
  * XPC calls this when it (the XPC module) is being unloaded.
@@ -95,6 +103,7 @@ xpc_clear_interface(void)
 	xpc_interface.partid_to_nasids = (enum xpc_retval(*)(partid_t, void *))
 	    xpc_notloaded;
 }
+EXPORT_SYMBOL_GPL(xpc_clear_interface);
 
 /*
  * Register for automatic establishment of a channel connection whenever
@@ -133,9 +142,8 @@ xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
 
 	registration = &xpc_registrations[ch_number];
 
-	if (mutex_lock_interruptible(&registration->mutex) != 0) {
+	if (mutex_lock_interruptible(&registration->mutex) != 0)
 		return xpcInterrupted;
-	}
 
 	/* if XPC_CHANNEL_REGISTERED(ch_number) */
 	if (registration->func != NULL) {
@@ -157,6 +165,7 @@ xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
 
 	return xpcSuccess;
 }
+EXPORT_SYMBOL_GPL(xpc_connect);
 
 /*
  * Remove the registration for automatic connection of the specified channel
@@ -207,6 +216,7 @@ xpc_disconnect(int ch_number)
 
 	return;
 }
+EXPORT_SYMBOL_GPL(xpc_disconnect);
 
 int __init
 xp_init(void)
@@ -215,9 +225,8 @@ xp_init(void)
 	u64 func_addr = *(u64 *)xp_nofault_PIOR;
 	u64 err_func_addr = *(u64 *)xp_error_PIOR;
 
-	if (!ia64_platform_is("sn2")) {
+	if (!ia64_platform_is("sn2"))
 		return -ENODEV;
-	}
 
 	/*
 	 * Register a nofault code region which performs a cross-partition
@@ -228,8 +237,9 @@ xp_init(void)
 	 * least some CPUs on Shubs <= v1.2, which unfortunately we have to
 	 * work around).
 	 */
-	if ((ret = sn_register_nofault_code(func_addr, err_func_addr,
-					    err_func_addr, 1, 1)) != 0) {
+	ret = sn_register_nofault_code(func_addr, err_func_addr, err_func_addr,
+				       1, 1);
+	if (ret != 0) {
 		printk(KERN_ERR "XP: can't register nofault code, error=%d\n",
 		       ret);
 	}
@@ -237,16 +247,14 @@ xp_init(void)
 	 * Setup the nofault PIO read target. (There is no special reason why
 	 * SH_IPI_ACCESS was selected.)
 	 */
-	if (is_shub2()) {
+	if (is_shub2())
 		xp_nofault_PIOR_target = SH2_IPI_ACCESS0;
-	} else {
+	else
 		xp_nofault_PIOR_target = SH1_IPI_ACCESS;
-	}
 
 	/* initialize the connection registration mutex */
-	for (ch_number = 0; ch_number < XPC_NCHANNELS; ch_number++) {
+	for (ch_number = 0; ch_number < XPC_NCHANNELS; ch_number++)
 		mutex_init(&xpc_registrations[ch_number].mutex);
-	}
 
 	return 0;
 }
@@ -269,12 +277,3 @@ module_exit(xp_exit);
 MODULE_AUTHOR("Silicon Graphics, Inc.");
 MODULE_DESCRIPTION("Cross Partition (XP) base");
 MODULE_LICENSE("GPL");
-
-EXPORT_SYMBOL(xp_nofault_PIOR);
-EXPORT_SYMBOL(xp_nofault_PIOR_target);
-EXPORT_SYMBOL(xpc_registrations);
-EXPORT_SYMBOL(xpc_interface);
-EXPORT_SYMBOL(xpc_clear_interface);
-EXPORT_SYMBOL(xpc_set_interface);
-EXPORT_SYMBOL(xpc_connect);
-EXPORT_SYMBOL(xpc_disconnect);
diff --git a/drivers/misc/sgi-xp/xpc.h b/drivers/misc/sgi-xp/xpc.h
index 64368bb8889..9eb6d4a3269 100644
--- a/drivers/misc/sgi-xp/xpc.h
+++ b/drivers/misc/sgi-xp/xpc.h
@@ -110,16 +110,16 @@ struct xpc_rsvd_page {
 	u8 partid;		/* SAL: partition ID */
 	u8 version;
 	u8 pad1[6];		/* align to next u64 in cacheline */
-	volatile u64 vars_pa;
+	u64 vars_pa;		/* physical address of struct xpc_vars */
 	struct timespec stamp;	/* time when reserved page was setup by XPC */
 	u64 pad2[9];		/* align to last u64 in cacheline */
 	u64 nasids_size;	/* SAL: size of each nasid mask in bytes */
 };
 
-#define XPC_RP_VERSION _XPC_VERSION(1,1)	/* version 1.1 of the reserved page */
+#define XPC_RP_VERSION _XPC_VERSION(1, 1) /* version 1.1 of the reserved page */
 
 #define XPC_SUPPORTS_RP_STAMP(_version) \
-			(_version >= _XPC_VERSION(1,1))
+			(_version >= _XPC_VERSION(1, 1))
 
 /*
  * compare stamps - the return value is:
@@ -133,9 +133,10 @@ xpc_compare_stamps(struct timespec *stamp1, struct timespec *stamp2)
 {
 	int ret;
 
-	if ((ret = stamp1->tv_sec - stamp2->tv_sec) == 0) {
+	ret = stamp1->tv_sec - stamp2->tv_sec;
+	if (ret == 0)
 		ret = stamp1->tv_nsec - stamp2->tv_nsec;
-	}
+
 	return ret;
 }
 
@@ -165,10 +166,10 @@ struct xpc_vars {
 	AMO_t *amos_page;	/* vaddr of page of AMOs from MSPEC driver */
 };
 
-#define XPC_V_VERSION _XPC_VERSION(3,1)	/* version 3.1 of the cross vars */
+#define XPC_V_VERSION _XPC_VERSION(3, 1)    /* version 3.1 of the cross vars */
 
 #define XPC_SUPPORTS_DISENGAGE_REQUEST(_version) \
-			(_version >= _XPC_VERSION(3,1))
+			(_version >= _XPC_VERSION(3, 1))
 
 static inline int
 xpc_hb_allowed(partid_t partid, struct xpc_vars *vars)
@@ -224,7 +225,7 @@ xpc_disallow_hb(partid_t partid, struct xpc_vars *vars)
  * occupies half a cacheline.
  */
 struct xpc_vars_part {
-	volatile u64 magic;
+	u64 magic;
 
 	u64 openclose_args_pa;	/* physical address of open and close args */
 	u64 GPs_pa;		/* physical address of Get/Put values */
@@ -247,18 +248,20 @@ struct xpc_vars_part {
  * MAGIC2 indicates that this partition has pulled the remote partititions
  * per partition variables that pertain to this partition.
  */
-#define XPC_VP_MAGIC1	0x0053524156435058L	/* 'XPCVARS\0'L (little endian) */
-#define XPC_VP_MAGIC2	0x0073726176435058L	/* 'XPCvars\0'L (little endian) */
+#define XPC_VP_MAGIC1	0x0053524156435058L   /* 'XPCVARS\0'L (little endian) */
+#define XPC_VP_MAGIC2	0x0073726176435058L   /* 'XPCvars\0'L (little endian) */
 
 /* the reserved page sizes and offsets */
 
 #define XPC_RP_HEADER_SIZE	L1_CACHE_ALIGN(sizeof(struct xpc_rsvd_page))
-#define XPC_RP_VARS_SIZE 	L1_CACHE_ALIGN(sizeof(struct xpc_vars))
+#define XPC_RP_VARS_SIZE	L1_CACHE_ALIGN(sizeof(struct xpc_vars))
 
-#define XPC_RP_PART_NASIDS(_rp) (u64 *) ((u8 *) _rp + XPC_RP_HEADER_SIZE)
+#define XPC_RP_PART_NASIDS(_rp) ((u64 *)((u8 *)(_rp) + XPC_RP_HEADER_SIZE))
 #define XPC_RP_MACH_NASIDS(_rp) (XPC_RP_PART_NASIDS(_rp) + xp_nasid_mask_words)
-#define XPC_RP_VARS(_rp)	((struct xpc_vars *) XPC_RP_MACH_NASIDS(_rp) + xp_nasid_mask_words)
-#define XPC_RP_VARS_PART(_rp)	(struct xpc_vars_part *) ((u8 *) XPC_RP_VARS(rp) + XPC_RP_VARS_SIZE)
+#define XPC_RP_VARS(_rp)	((struct xpc_vars *)(XPC_RP_MACH_NASIDS(_rp) + \
+				    xp_nasid_mask_words))
+#define XPC_RP_VARS_PART(_rp)	((struct xpc_vars_part *) \
+				    ((u8 *)XPC_RP_VARS(_rp) + XPC_RP_VARS_SIZE))
 
 /*
  * Functions registered by add_timer() or called by kernel_thread() only
@@ -277,8 +280,8 @@ struct xpc_vars_part {
  * Define a Get/Put value pair (pointers) used with a message queue.
  */
 struct xpc_gp {
-	volatile s64 get;	/* Get value */
-	volatile s64 put;	/* Put value */
+	s64 get;		/* Get value */
+	s64 put;		/* Put value */
 };
 
 #define XPC_GP_SIZE \
@@ -315,7 +318,7 @@ struct xpc_openclose_args {
  * and consumed by the intended recipient.
  */
 struct xpc_notify {
-	volatile u8 type;	/* type of notification */
+	u8 type;		/* type of notification */
 
 	/* the following two fields are only used if type == XPC_N_CALL */
 	xpc_notify_func func;	/* user's notify function */
@@ -421,8 +424,8 @@ struct xpc_channel {
 	void *local_msgqueue_base;	/* base address of kmalloc'd space */
 	struct xpc_msg *local_msgqueue;	/* local message queue */
 	void *remote_msgqueue_base;	/* base address of kmalloc'd space */
-	struct xpc_msg *remote_msgqueue;	/* cached copy of remote partition's */
-						/* local message queue */
+	struct xpc_msg *remote_msgqueue; /* cached copy of remote partition's */
+					 /* local message queue */
 	u64 remote_msgqueue_pa;	/* phys addr of remote partition's */
 				/* local message queue */
 
@@ -437,16 +440,16 @@ struct xpc_channel {
 	/* queue of msg senders who want to be notified when msg received */
 
 	atomic_t n_to_notify;	/* #of msg senders to notify */
-	struct xpc_notify *notify_queue;	/* notify queue for messages sent */
+	struct xpc_notify *notify_queue;    /* notify queue for messages sent */
 
 	xpc_channel_func func;	/* user's channel function */
 	void *key;		/* pointer to user's key */
 
 	struct mutex msg_to_pull_mutex;	/* next msg to pull serialization */
-	struct completion wdisconnect_wait;	/* wait for channel disconnect */
+	struct completion wdisconnect_wait;    /* wait for channel disconnect */
 
-	struct xpc_openclose_args *local_openclose_args;	/* args passed on */
-								/* opening or closing of channel */
+	struct xpc_openclose_args *local_openclose_args; /* args passed on */
+					     /* opening or closing of channel */
 
 	/* various flavors of local and remote Get/Put values */
 
@@ -458,16 +461,11 @@ struct xpc_channel {
 
 	/* kthread management related fields */
 
-// >>> rethink having kthreads_assigned_limit and kthreads_idle_limit; perhaps
-// >>> allow the assigned limit be unbounded and let the idle limit be dynamic
-// >>> dependent on activity over the last interval of time
 	atomic_t kthreads_assigned;	/* #of kthreads assigned to channel */
 	u32 kthreads_assigned_limit;	/* limit on #of kthreads assigned */
 	atomic_t kthreads_idle;	/* #of kthreads idle waiting for work */
 	u32 kthreads_idle_limit;	/* limit on #of kthreads idle */
 	atomic_t kthreads_active;	/* #of kthreads actively working */
-	// >>> following field is temporary
-	u32 kthreads_created;	/* total #of kthreads created */
 
 	wait_queue_head_t idle_wq;	/* idle kthread wait queue */
 
@@ -479,28 +477,28 @@ struct xpc_channel {
 
 #define	XPC_C_ROPENREPLY	0x00000002	/* remote open channel reply */
 #define	XPC_C_OPENREPLY		0x00000004	/* local open channel reply */
-#define	XPC_C_ROPENREQUEST	0x00000008	/* remote open channel request */
+#define	XPC_C_ROPENREQUEST	0x00000008     /* remote open channel request */
 #define	XPC_C_OPENREQUEST	0x00000010	/* local open channel request */
 
-#define	XPC_C_SETUP		0x00000020	/* channel's msgqueues are alloc'd */
-#define	XPC_C_CONNECTEDCALLOUT	0x00000040	/* connected callout initiated */
+#define	XPC_C_SETUP		0x00000020 /* channel's msgqueues are alloc'd */
+#define	XPC_C_CONNECTEDCALLOUT	0x00000040     /* connected callout initiated */
 #define	XPC_C_CONNECTEDCALLOUT_MADE \
-				0x00000080	/* connected callout completed */
+				0x00000080     /* connected callout completed */
 #define	XPC_C_CONNECTED		0x00000100	/* local channel is connected */
 #define	XPC_C_CONNECTING	0x00000200	/* channel is being connected */
 
 #define	XPC_C_RCLOSEREPLY	0x00000400	/* remote close channel reply */
 #define	XPC_C_CLOSEREPLY	0x00000800	/* local close channel reply */
-#define	XPC_C_RCLOSEREQUEST	0x00001000	/* remote close channel request */
-#define	XPC_C_CLOSEREQUEST	0x00002000	/* local close channel request */
+#define	XPC_C_RCLOSEREQUEST	0x00001000    /* remote close channel request */
+#define	XPC_C_CLOSEREQUEST	0x00002000     /* local close channel request */
 
 #define	XPC_C_DISCONNECTED	0x00004000	/* channel is disconnected */
-#define	XPC_C_DISCONNECTING	0x00008000	/* channel is being disconnected */
+#define	XPC_C_DISCONNECTING	0x00008000   /* channel is being disconnected */
 #define	XPC_C_DISCONNECTINGCALLOUT \
-				0x00010000	/* disconnecting callout initiated */
+				0x00010000 /* disconnecting callout initiated */
 #define	XPC_C_DISCONNECTINGCALLOUT_MADE \
-				0x00020000	/* disconnecting callout completed */
-#define	XPC_C_WDISCONNECT	0x00040000	/* waiting for channel disconnect */
+				0x00020000 /* disconnecting callout completed */
+#define	XPC_C_WDISCONNECT	0x00040000  /* waiting for channel disconnect */
 
 /*
  * Manages channels on a partition basis. There is one of these structures
@@ -512,7 +510,7 @@ struct xpc_partition {
 	/* XPC HB infrastructure */
 
 	u8 remote_rp_version;	/* version# of partition's rsvd pg */
-	struct timespec remote_rp_stamp;	/* time when rsvd pg was initialized */
+	struct timespec remote_rp_stamp; /* time when rsvd pg was initialized */
 	u64 remote_rp_pa;	/* phys addr of partition's rsvd pg */
 	u64 remote_vars_pa;	/* phys addr of partition's vars */
 	u64 remote_vars_part_pa;	/* phys addr of partition's vars part */
@@ -533,7 +531,7 @@ struct xpc_partition {
 
 	/* XPC infrastructure referencing and teardown control */
 
-	volatile u8 setup_state;	/* infrastructure setup state */
+	u8 setup_state;		/* infrastructure setup state */
 	wait_queue_head_t teardown_wq;	/* kthread waiting to teardown infra */
 	atomic_t references;	/* #of references to infrastructure */
 
@@ -545,32 +543,32 @@ struct xpc_partition {
 	 */
 
 	u8 nchannels;		/* #of defined channels supported */
-	atomic_t nchannels_active;	/* #of channels that are not DISCONNECTED */
-	atomic_t nchannels_engaged;	/* #of channels engaged with remote part */
+	atomic_t nchannels_active;  /* #of channels that are not DISCONNECTED */
+	atomic_t nchannels_engaged;  /* #of channels engaged with remote part */
 	struct xpc_channel *channels;	/* array of channel structures */
 
 	void *local_GPs_base;	/* base address of kmalloc'd space */
 	struct xpc_gp *local_GPs;	/* local Get/Put values */
 	void *remote_GPs_base;	/* base address of kmalloc'd space */
-	struct xpc_gp *remote_GPs;	/* copy of remote partition's local Get/Put */
-					/* values */
+	struct xpc_gp *remote_GPs;	/* copy of remote partition's local */
+					/* Get/Put values */
 	u64 remote_GPs_pa;	/* phys address of remote partition's local */
 				/* Get/Put values */
 
 	/* fields used to pass args when opening or closing a channel */
 
-	void *local_openclose_args_base;	/* base address of kmalloc'd space */
-	struct xpc_openclose_args *local_openclose_args;	/* local's args */
-	void *remote_openclose_args_base;	/* base address of kmalloc'd space */
-	struct xpc_openclose_args *remote_openclose_args;	/* copy of remote's */
-								/* args */
+	void *local_openclose_args_base;   /* base address of kmalloc'd space */
+	struct xpc_openclose_args *local_openclose_args;      /* local's args */
+	void *remote_openclose_args_base;  /* base address of kmalloc'd space */
+	struct xpc_openclose_args *remote_openclose_args; /* copy of remote's */
+							  /* args */
 	u64 remote_openclose_args_pa;	/* phys addr of remote's args */
 
 	/* IPI sending, receiving and handling related fields */
 
 	int remote_IPI_nasid;	/* nasid of where to send IPIs */
 	int remote_IPI_phys_cpuid;	/* phys CPU ID of where to send IPIs */
-	AMO_t *remote_IPI_amo_va;	/* address of remote IPI AMO_t structure */
+	AMO_t *remote_IPI_amo_va;    /* address of remote IPI AMO_t structure */
 
 	AMO_t *local_IPI_amo_va;	/* address of IPI AMO_t structure */
 	u64 local_IPI_amo;	/* IPI amo flags yet to be handled */
@@ -678,9 +676,8 @@ extern void xpc_teardown_infrastructure(struct xpc_partition *);
 static inline void
 xpc_wakeup_channel_mgr(struct xpc_partition *part)
 {
-	if (atomic_inc_return(&part->channel_mgr_requests) == 1) {
+	if (atomic_inc_return(&part->channel_mgr_requests) == 1)
 		wake_up(&part->channel_mgr_wq);
-	}
 }
 
 /*
@@ -699,9 +696,8 @@ xpc_msgqueue_deref(struct xpc_channel *ch)
 	s32 refs = atomic_dec_return(&ch->references);
 
 	DBUG_ON(refs < 0);
-	if (refs == 0) {
+	if (refs == 0)
 		xpc_wakeup_channel_mgr(&xpc_partitions[ch->partid]);
-	}
 }
 
 #define XPC_DISCONNECT_CHANNEL(_ch, _reason, _irqflgs) \
@@ -717,9 +713,8 @@ xpc_part_deref(struct xpc_partition *part)
 	s32 refs = atomic_dec_return(&part->references);
 
 	DBUG_ON(refs < 0);
-	if (refs == 0 && part->setup_state == XPC_P_WTEARDOWN) {
+	if (refs == 0 && part->setup_state == XPC_P_WTEARDOWN)
 		wake_up(&part->teardown_wq);
-	}
 }
 
 static inline int
@@ -729,9 +724,9 @@ xpc_part_ref(struct xpc_partition *part)
 
 	atomic_inc(&part->references);
 	setup = (part->setup_state == XPC_P_SETUP);
-	if (!setup) {
+	if (!setup)
 		xpc_part_deref(part);
-	}
+
 	return setup;
 }
 
@@ -1007,13 +1002,11 @@ xpc_notify_IRQ_send(struct xpc_channel *ch, u8 ipi_flag, char *ipi_flag_string,
 		dev_dbg(xpc_chan, "%s sent to partid=%d, channel=%d, ret=%d\n",
 			ipi_flag_string, ch->partid, ch->number, ret);
 		if (unlikely(ret != xpcSuccess)) {
-			if (irq_flags != NULL) {
+			if (irq_flags != NULL)
 				spin_unlock_irqrestore(&ch->lock, *irq_flags);
-			}
 			XPC_DEACTIVATE_PARTITION(part, ret);
-			if (irq_flags != NULL) {
+			if (irq_flags != NULL)
 				spin_lock_irqsave(&ch->lock, *irq_flags);
-			}
 		}
 	}
 }
@@ -1056,8 +1049,8 @@ xpc_notify_IRQ_send_local(struct xpc_channel *ch, u8 ipi_flag,
 #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) & __IA64_UL_CONST(0x0f0f0f0f0f0f0f0f))
-#define XPC_ANY_MSG_IPI_FLAGS_SET(_amo)       ((_amo) & __IA64_UL_CONST(0x1010101010101010))
+#define	XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(_amo) ((_amo) & 0x0f0f0f0f0f0f0f0fUL)
+#define XPC_ANY_MSG_IPI_FLAGS_SET(_amo)       ((_amo) & 0x1010101010101010UL)
 
 static inline void
 xpc_IPI_send_closerequest(struct xpc_channel *ch, unsigned long *irq_flags)
@@ -1178,9 +1171,8 @@ xpc_check_for_channel_activity(struct xpc_partition *part)
 	unsigned long irq_flags;
 
 	IPI_amo = xpc_IPI_receive(part->local_IPI_amo_va);
-	if (IPI_amo == 0) {
+	if (IPI_amo == 0)
 		return;
-	}
 
 	spin_lock_irqsave(&part->IPI_lock, irq_flags);
 	part->local_IPI_amo |= IPI_amo;
diff --git a/drivers/misc/sgi-xp/xpc_channel.c b/drivers/misc/sgi-xp/xpc_channel.c
index 15cb91a8210..bfcb9ea968e 100644
--- a/drivers/misc/sgi-xp/xpc_channel.c
+++ b/drivers/misc/sgi-xp/xpc_channel.c
@@ -33,19 +33,19 @@ xpc_kzalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
 {
 	/* see if kzalloc will give us cachline aligned memory by default */
 	*base = kzalloc(size, flags);
-	if (*base == NULL) {
+	if (*base == NULL)
 		return NULL;
-	}
-	if ((u64)*base == L1_CACHE_ALIGN((u64)*base)) {
+
+	if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
 		return *base;
-	}
+
 	kfree(*base);
 
 	/* nope, we'll have to do it ourselves */
 	*base = kzalloc(size + L1_CACHE_BYTES, flags);
-	if (*base == NULL) {
+	if (*base == NULL)
 		return NULL;
-	}
+
 	return (void *)L1_CACHE_ALIGN((u64)*base);
 }
 
@@ -264,15 +264,13 @@ xpc_pull_remote_cachelines(struct xpc_partition *part, void *dst,
 	DBUG_ON((u64)dst != L1_CACHE_ALIGN((u64)dst));
 	DBUG_ON(cnt != L1_CACHE_ALIGN(cnt));
 
-	if (part->act_state == XPC_P_DEACTIVATING) {
+	if (part->act_state == XPC_P_DEACTIVATING)
 		return part->reason;
-	}
 
 	bte_ret = xp_bte_copy((u64)src, (u64)dst, (u64)cnt,
 			      (BTE_NORMAL | BTE_WACQUIRE), NULL);
-	if (bte_ret == BTE_SUCCESS) {
+	if (bte_ret == BTE_SUCCESS)
 		return xpcSuccess;
-	}
 
 	dev_dbg(xpc_chan, "xp_bte_copy() from partition %d failed, ret=%d\n",
 		XPC_PARTID(part), bte_ret);
@@ -359,18 +357,16 @@ xpc_pull_remote_vars_part(struct xpc_partition *part)
 		part->remote_IPI_nasid = pulled_entry->IPI_nasid;
 		part->remote_IPI_phys_cpuid = pulled_entry->IPI_phys_cpuid;
 
-		if (part->nchannels > pulled_entry->nchannels) {
+		if (part->nchannels > pulled_entry->nchannels)
 			part->nchannels = pulled_entry->nchannels;
-		}
 
 		/* let the other side know that we've pulled their variables */
 
 		xpc_vars_part[partid].magic = XPC_VP_MAGIC2;
 	}
 
-	if (pulled_entry->magic == XPC_VP_MAGIC1) {
+	if (pulled_entry->magic == XPC_VP_MAGIC1)
 		return xpcRetry;
-	}
 
 	return xpcSuccess;
 }
@@ -390,9 +386,10 @@ xpc_get_IPI_flags(struct xpc_partition *part)
 	 */
 
 	spin_lock_irqsave(&part->IPI_lock, irq_flags);
-	if ((IPI_amo = part->local_IPI_amo) != 0) {
+	IPI_amo = part->local_IPI_amo;
+	if (IPI_amo != 0)
 		part->local_IPI_amo = 0;
-	}
+
 	spin_unlock_irqrestore(&part->IPI_lock, irq_flags);
 
 	if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_amo)) {
@@ -441,20 +438,14 @@ xpc_allocate_local_msgqueue(struct xpc_channel *ch)
 	int nentries;
 	size_t nbytes;
 
-	// >>> may want to check for ch->flags & XPC_C_DISCONNECTING between
-	// >>> iterations of the for-loop, bail if set?
-
-	// >>> should we impose a minimum #of entries? like 4 or 8?
 	for (nentries = ch->local_nentries; nentries > 0; nentries--) {
 
 		nbytes = nentries * ch->msg_size;
 		ch->local_msgqueue = xpc_kzalloc_cacheline_aligned(nbytes,
 								   GFP_KERNEL,
-								   &ch->
-								   local_msgqueue_base);
-		if (ch->local_msgqueue == NULL) {
+						      &ch->local_msgqueue_base);
+		if (ch->local_msgqueue == NULL)
 			continue;
-		}
 
 		nbytes = nentries * sizeof(struct xpc_notify);
 		ch->notify_queue = kzalloc(nbytes, GFP_KERNEL);
@@ -493,20 +484,14 @@ xpc_allocate_remote_msgqueue(struct xpc_channel *ch)
 
 	DBUG_ON(ch->remote_nentries <= 0);
 
-	// >>> may want to check for ch->flags & XPC_C_DISCONNECTING between
-	// >>> iterations of the for-loop, bail if set?
-
-	// >>> should we impose a minimum #of entries? like 4 or 8?
 	for (nentries = ch->remote_nentries; nentries > 0; nentries--) {
 
 		nbytes = nentries * ch->msg_size;
 		ch->remote_msgqueue = xpc_kzalloc_cacheline_aligned(nbytes,
 								    GFP_KERNEL,
-								    &ch->
-								    remote_msgqueue_base);
-		if (ch->remote_msgqueue == NULL) {
+						     &ch->remote_msgqueue_base);
+		if (ch->remote_msgqueue == NULL)
 			continue;
-		}
 
 		spin_lock_irqsave(&ch->lock, irq_flags);
 		if (nentries < ch->remote_nentries) {
@@ -538,11 +523,12 @@ xpc_allocate_msgqueues(struct xpc_channel *ch)
 
 	DBUG_ON(ch->flags & XPC_C_SETUP);
 
-	if ((ret = xpc_allocate_local_msgqueue(ch)) != xpcSuccess) {
+	ret = xpc_allocate_local_msgqueue(ch);
+	if (ret != xpcSuccess)
 		return ret;
-	}
 
-	if ((ret = xpc_allocate_remote_msgqueue(ch)) != xpcSuccess) {
+	ret = xpc_allocate_remote_msgqueue(ch);
+	if (ret != xpcSuccess) {
 		kfree(ch->local_msgqueue_base);
 		ch->local_msgqueue = NULL;
 		kfree(ch->notify_queue);
@@ -582,12 +568,11 @@ xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
 		ret = xpc_allocate_msgqueues(ch);
 		spin_lock_irqsave(&ch->lock, *irq_flags);
 
-		if (ret != xpcSuccess) {
+		if (ret != xpcSuccess)
 			XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags);
-		}
-		if (ch->flags & (XPC_C_CONNECTED | XPC_C_DISCONNECTING)) {
+
+		if (ch->flags & (XPC_C_CONNECTED | XPC_C_DISCONNECTING))
 			return;
-		}
 
 		DBUG_ON(!(ch->flags & XPC_C_SETUP));
 		DBUG_ON(ch->local_msgqueue == NULL);
@@ -599,9 +584,8 @@ xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
 		xpc_IPI_send_openreply(ch, irq_flags);
 	}
 
-	if (!(ch->flags & XPC_C_ROPENREPLY)) {
+	if (!(ch->flags & XPC_C_ROPENREPLY))
 		return;
-	}
 
 	DBUG_ON(ch->remote_msgqueue_pa == 0);
 
@@ -719,9 +703,8 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 
 	DBUG_ON(!spin_is_locked(&ch->lock));
 
-	if (!(ch->flags & XPC_C_DISCONNECTING)) {
+	if (!(ch->flags & XPC_C_DISCONNECTING))
 		return;
-	}
 
 	DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
 
@@ -736,26 +719,23 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 
 	if (part->act_state == XPC_P_DEACTIVATING) {
 		/* can't proceed until the other side disengages from us */
-		if (xpc_partition_engaged(1UL << ch->partid)) {
+		if (xpc_partition_engaged(1UL << ch->partid))
 			return;
-		}
 
 	} else {
 
 		/* as long as the other side is up do the full protocol */
 
-		if (!(ch->flags & XPC_C_RCLOSEREQUEST)) {
+		if (!(ch->flags & XPC_C_RCLOSEREQUEST))
 			return;
-		}
 
 		if (!(ch->flags & XPC_C_CLOSEREPLY)) {
 			ch->flags |= XPC_C_CLOSEREPLY;
 			xpc_IPI_send_closereply(ch, irq_flags);
 		}
 
-		if (!(ch->flags & XPC_C_RCLOSEREPLY)) {
+		if (!(ch->flags & XPC_C_RCLOSEREPLY))
 			return;
-		}
 	}
 
 	/* wake those waiting for notify completion */
@@ -815,9 +795,10 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
 
 	spin_lock_irqsave(&ch->lock, irq_flags);
 
-      again:
+again:
 
-	if ((ch->flags & XPC_C_DISCONNECTED) && (ch->flags & XPC_C_WDISCONNECT)) {
+	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.
@@ -890,11 +871,10 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
 
 		if (!(ch->flags & XPC_C_DISCONNECTING)) {
 			reason = args->reason;
-			if (reason <= xpcSuccess || reason > xpcUnknownReason) {
+			if (reason <= xpcSuccess || reason > xpcUnknownReason)
 				reason = xpcUnknownReason;
-			} else if (reason == xpcUnregistering) {
+			else if (reason == xpcUnregistering)
 				reason = xpcOtherUnregistering;
-			}
 
 			XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
 
@@ -1068,9 +1048,8 @@ xpc_connect_channel(struct xpc_channel *ch)
 	unsigned long irq_flags;
 	struct xpc_registration *registration = &xpc_registrations[ch->number];
 
-	if (mutex_trylock(&registration->mutex) == 0) {
+	if (mutex_trylock(&registration->mutex) == 0)
 		return xpcRetry;
-	}
 
 	if (!XPC_CHANNEL_REGISTERED(ch->number)) {
 		mutex_unlock(&registration->mutex);
@@ -1159,7 +1138,7 @@ xpc_clear_local_msgqueue_flags(struct xpc_channel *ch)
 					 (get % ch->local_nentries) *
 					 ch->msg_size);
 		msg->flags = 0;
-	} while (++get < (volatile s64)ch->remote_GP.get);
+	} while (++get < ch->remote_GP.get);
 }
 
 /*
@@ -1177,7 +1156,7 @@ xpc_clear_remote_msgqueue_flags(struct xpc_channel *ch)
 					 (put % ch->remote_nentries) *
 					 ch->msg_size);
 		msg->flags = 0;
-	} while (++put < (volatile s64)ch->remote_GP.put);
+	} while (++put < ch->remote_GP.put);
 }
 
 static void
@@ -1244,9 +1223,8 @@ xpc_process_msg_IPI(struct xpc_partition *part, int ch_number)
 		 * If anyone was waiting for message queue entries to become
 		 * available, wake them up.
 		 */
-		if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) {
+		if (atomic_read(&ch->n_on_msg_allocate_wq) > 0)
 			wake_up(&ch->msg_allocate_wq);
-		}
 	}
 
 	/*
@@ -1273,9 +1251,8 @@ xpc_process_msg_IPI(struct xpc_partition *part, int ch_number)
 				"delivered=%d, partid=%d, channel=%d\n",
 				nmsgs_sent, ch->partid, ch->number);
 
-			if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) {
+			if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE)
 				xpc_activate_kthreads(ch, nmsgs_sent);
-			}
 		}
 	}
 
@@ -1310,9 +1287,8 @@ xpc_process_channel_activity(struct xpc_partition *part)
 
 		IPI_flags = XPC_GET_IPI_FLAGS(IPI_amo, ch_number);
 
-		if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_flags)) {
+		if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_flags))
 			xpc_process_openclose_IPI(part, ch_number, IPI_flags);
-		}
 
 		ch_flags = ch->flags;	/* need an atomic snapshot of flags */
 
@@ -1323,9 +1299,8 @@ xpc_process_channel_activity(struct xpc_partition *part)
 			continue;
 		}
 
-		if (part->act_state == XPC_P_DEACTIVATING) {
+		if (part->act_state == XPC_P_DEACTIVATING)
 			continue;
-		}
 
 		if (!(ch_flags & XPC_C_CONNECTED)) {
 			if (!(ch_flags & XPC_C_OPENREQUEST)) {
@@ -1345,9 +1320,8 @@ xpc_process_channel_activity(struct xpc_partition *part)
 		 * from the other partition.
 		 */
 
-		if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_flags)) {
+		if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_flags))
 			xpc_process_msg_IPI(part, ch_number);
-		}
 	}
 }
 
@@ -1560,9 +1534,9 @@ xpc_disconnect_channel(const int line, struct xpc_channel *ch,
 
 	DBUG_ON(!spin_is_locked(&ch->lock));
 
-	if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) {
+	if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED))
 		return;
-	}
+
 	DBUG_ON(!(ch->flags & (XPC_C_CONNECTING | XPC_C_CONNECTED)));
 
 	dev_dbg(xpc_chan, "reason=%d, line=%d, partid=%d, channel=%d\n",
@@ -1578,9 +1552,8 @@ xpc_disconnect_channel(const int line, struct xpc_channel *ch,
 
 	xpc_IPI_send_closerequest(ch, irq_flags);
 
-	if (channel_was_connected) {
+	if (channel_was_connected)
 		ch->flags |= XPC_C_WASCONNECTED;
-	}
 
 	spin_unlock_irqrestore(&ch->lock, *irq_flags);
 
@@ -1595,9 +1568,8 @@ xpc_disconnect_channel(const int line, struct xpc_channel *ch,
 	}
 
 	/* wake those waiting to allocate an entry from the local msg queue */
-	if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) {
+	if (atomic_read(&ch->n_on_msg_allocate_wq) > 0)
 		wake_up(&ch->msg_allocate_wq);
-	}
 
 	spin_lock_irqsave(&ch->lock, *irq_flags);
 }
@@ -1632,7 +1604,7 @@ xpc_allocate_msg_wait(struct xpc_channel *ch)
 	enum xpc_retval ret;
 
 	if (ch->flags & XPC_C_DISCONNECTING) {
-		DBUG_ON(ch->reason == xpcInterrupted);	// >>> Is this true?
+		DBUG_ON(ch->reason == xpcInterrupted);
 		return ch->reason;
 	}
 
@@ -1642,7 +1614,7 @@ xpc_allocate_msg_wait(struct xpc_channel *ch)
 
 	if (ch->flags & XPC_C_DISCONNECTING) {
 		ret = ch->reason;
-		DBUG_ON(ch->reason == xpcInterrupted);	// >>> Is this true?
+		DBUG_ON(ch->reason == xpcInterrupted);
 	} else if (ret == 0) {
 		ret = xpcTimeout;
 	} else {
@@ -1685,9 +1657,9 @@ xpc_allocate_msg(struct xpc_channel *ch, u32 flags,
 
 	while (1) {
 
-		put = (volatile s64)ch->w_local_GP.put;
-		if (put - (volatile s64)ch->w_remote_GP.get <
-		    ch->local_nentries) {
+		put = ch->w_local_GP.put;
+		rmb();	/* guarantee that .put loads before .get */
+		if (put - ch->w_remote_GP.get < ch->local_nentries) {
 
 			/* There are available message entries. We need to try
 			 * to secure one for ourselves. We'll do this by trying
@@ -1711,9 +1683,8 @@ xpc_allocate_msg(struct xpc_channel *ch, u32 flags,
 		 * that will cause the IPI handler to fetch the latest
 		 * GP values as if an IPI was sent by the other side.
 		 */
-		if (ret == xpcTimeout) {
+		if (ret == xpcTimeout)
 			xpc_IPI_send_local_msgrequest(ch);
-		}
 
 		if (flags & XPC_NOWAIT) {
 			xpc_msgqueue_deref(ch);
@@ -1772,9 +1743,8 @@ xpc_initiate_allocate(partid_t partid, int ch_number, u32 flags, void **payload)
 		ret = xpc_allocate_msg(&part->channels[ch_number], flags, &msg);
 		xpc_part_deref(part);
 
-		if (msg != NULL) {
+		if (msg != NULL)
 			*payload = &msg->payload;
-		}
 	}
 
 	return ret;
@@ -1795,17 +1765,15 @@ xpc_send_msgs(struct xpc_channel *ch, s64 initial_put)
 	while (1) {
 
 		while (1) {
-			if (put == (volatile s64)ch->w_local_GP.put) {
+			if (put == ch->w_local_GP.put)
 				break;
-			}
 
 			msg = (struct xpc_msg *)((u64)ch->local_msgqueue +
 						 (put % ch->local_nentries) *
 						 ch->msg_size);
 
-			if (!(msg->flags & XPC_M_READY)) {
+			if (!(msg->flags & XPC_M_READY))
 				break;
-			}
 
 			put++;
 		}
@@ -1818,7 +1786,7 @@ xpc_send_msgs(struct xpc_channel *ch, s64 initial_put)
 		if (cmpxchg_rel(&ch->local_GP->put, initial_put, put) !=
 		    initial_put) {
 			/* someone else beat us to it */
-			DBUG_ON((volatile s64)ch->local_GP->put < initial_put);
+			DBUG_ON(ch->local_GP->put < initial_put);
 			break;
 		}
 
@@ -1837,9 +1805,8 @@ xpc_send_msgs(struct xpc_channel *ch, s64 initial_put)
 		initial_put = put;
 	}
 
-	if (send_IPI) {
+	if (send_IPI)
 		xpc_IPI_send_msgrequest(ch);
-	}
 }
 
 /*
@@ -1880,7 +1847,7 @@ xpc_send_msg(struct xpc_channel *ch, struct xpc_msg *msg, u8 notify_type,
 		notify->key = key;
 		notify->type = notify_type;
 
-		// >>> is a mb() needed here?
+		/* >>> is a mb() needed here? */
 
 		if (ch->flags & XPC_C_DISCONNECTING) {
 			/*
@@ -1913,9 +1880,8 @@ xpc_send_msg(struct xpc_channel *ch, struct xpc_msg *msg, u8 notify_type,
 	/* see if the message is next in line to be sent, if so send it */
 
 	put = ch->local_GP->put;
-	if (put == msg_number) {
+	if (put == msg_number)
 		xpc_send_msgs(ch, put);
-	}
 
 	/* drop the reference grabbed in xpc_allocate_msg() */
 	xpc_msgqueue_deref(ch);
@@ -2032,10 +1998,8 @@ xpc_pull_remote_msg(struct xpc_channel *ch, s64 get)
 
 		msg_index = ch->next_msg_to_pull % ch->remote_nentries