ide: remove hwgroup->hwif and {drive,hwif}->next

* Add 'int port_count' field to ide_hwgroup_t to keep the track of the number of ports in the hwgroup. Then update init_irq() and ide_remove_port_from_hwgroup() to use it. * Remove no longer needed hwgroup->hwif, {drive,hwif}->next, ide_add_drive_to_hwgroup() and ide_remove_drive_from_hwgroup() (hwgroup->drive now only denotes the currently active device in the hwgroup). * Update locking documentation in <linux/ide.h>. While at it: * Rename ->drive field in ide_hwgroup_t to ->cur_dev. * Use __func__ in ide_timer_expiry(). Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

ide: remove hwgroup->hwif and {drive,hwif}->next
* Add 'int port_count' field to ide_hwgroup_t to keep the track of the number of ports in the hwgroup. Then update init_irq() and ide_remove_port_from_hwgroup() to use it. * Remove no longer needed hwgroup->hwif, {drive,hwif}->next, ide_add_drive_to_hwgroup() and ide_remove_drive_from_hwgroup() (hwgroup->drive now only denotes the currently active device in the hwgroup). * Update locking documentation in <linux/ide.h>. While at it: * Rename ->drive field in ide_hwgroup_t to ->cur_dev. * Use __func__ in ide_timer_expiry(). Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Bartlomiej Zolnierkiewicz
1 parent ae86afaee6
Showing 3 changed files with 15 additions and 100 deletions Side-by-side Diff
drivers/ide/ide-io.c
drivers/ide/ide-probe.c
include/linux/ide.h
@@ -742,12 +742,12 @@
 			 * set nIEN for previous port, drives in the
 			 * quirk_list may not like intr setups/cleanups
 			 */
-			if (prev_port && hwgroup->drive->quirk_list == 0)
+			if (prev_port && hwgroup->cur_dev->quirk_list == 0)
 				prev_port->tp_ops->set_irq(prev_port, 0);
  
 			hwif->host->cur_port = hwif;
 		}
-		hwgroup->drive = drive;
+		hwgroup->cur_dev = drive;
 		drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
  
 		spin_unlock_irq(&hwgroup->lock);
  
@@ -913,9 +913,9 @@
 		 * Either way, we don't really want to complain about anything.
 		 */
 	} else {
-		drive = hwgroup->drive;
+		drive = hwgroup->cur_dev;
 		if (!drive) {
-			printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
+			printk(KERN_ERR "%s: ->cur_dev was NULL\n", __func__);
 			hwgroup->handler = NULL;
 		} else {
 			ide_hwif_t *hwif;
@@ -1033,7 +1033,7 @@
  *	places
  *
  *	hwif is the interface in the group currently performing
- *	a command. hwgroup->drive is the drive and hwgroup->handler is
+ *	a command. hwgroup->cur_dev is the drive and hwgroup->handler is
  *	the IRQ handler to call. As we issue a command the handlers
  *	step through multiple states, reassigning the handler to the
  *	next step in the process. Unlike a smart SCSI controller IDE
@@ -1105,7 +1105,7 @@
 		goto out;
 	}
  
-	drive = hwgroup->drive;
+	drive = hwgroup->cur_dev;
 	if (!drive) {
 		/*
 		 * This should NEVER happen, and there isn't much
@@ -918,27 +918,9 @@
 	return 0;
 }
  
-static void ide_add_drive_to_hwgroup(ide_drive_t *drive)
-{
-	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
-
-	spin_lock_irq(&hwgroup->lock);
-	if (!hwgroup->drive) {
-		/* first drive for hwgroup. */
-		drive->next = drive;
-		hwgroup->drive = drive;
-		hwgroup->hwif = HWIF(hwgroup->drive);
-	} else {
-		drive->next = hwgroup->drive->next;
-		hwgroup->drive->next = drive;
-	}
-	spin_unlock_irq(&hwgroup->lock);
-}
-
 /*
  * For any present drive:
  * - allocate the block device queue
- * - link drive into the hwgroup
  */
 static int ide_port_setup_devices(ide_hwif_t *hwif)
 {
@@ -961,8 +943,6 @@
 		}
  
 		j++;
-
-		ide_add_drive_to_hwgroup(drive);
 	}
 	mutex_unlock(&ide_cfg_mtx);
  
  
@@ -978,33 +958,9 @@
 	ide_ports[hwif->index] = NULL;
  
 	spin_lock_irq(&hwgroup->lock);
-	/*
-	 * Remove us from the hwgroup, and free
-	 * the hwgroup if we were the only member
-	 */
-	if (hwif->next == hwif) {
-		BUG_ON(hwgroup->hwif != hwif);
+	/* Free the hwgroup if we were the only member. */
+	if (--hwgroup->port_count == 0)
 		kfree(hwgroup);
-	} else {
-		/* There is another interface in hwgroup.
-		 * Unlink us, and set hwgroup->drive and ->hwif to
-		 * something sane.
-		 */
-		ide_hwif_t *g = hwgroup->hwif;
-
-		while (g->next != hwif)
-			g = g->next;
-		g->next = hwif->next;
-		if (hwgroup->hwif == hwif) {
-			/* Chose a random hwif for hwgroup->hwif.
-			 * It's guaranteed that there are no drives
-			 * left in the hwgroup.
-			 */
-			BUG_ON(hwgroup->drive != NULL);
-			hwgroup->hwif = g;
-		}
-		BUG_ON(hwgroup->hwif == hwif);
-	}
 	spin_unlock_irq(&hwgroup->lock);
 }
  
  
@@ -1044,20 +1000,9 @@
 	if (match) {
 		hwgroup = match->hwgroup;
 		hwif->hwgroup = hwgroup;
-		/*
-		 * Link us into the hwgroup.
-		 * This must be done early, do ensure that unexpected_intr
-		 * can find the hwif and prevent irq storms.
-		 * No drives are attached to the new hwif, choose_drive
-		 * can't do anything stupid (yet).
-		 * Add ourself as the 2nd entry to the hwgroup->hwif
-		 * linked list, the first entry is the hwif that owns
-		 * hwgroup->handler - do not change that.
-		 */
+
 		spin_lock_irq(&hwgroup->lock);
-		hwif->next = hwgroup->hwif->next;
-		hwgroup->hwif->next = hwif;
-		BUG_ON(hwif->next == hwif);
+		hwgroup->port_count++;
 		spin_unlock_irq(&hwgroup->lock);
 	} else {
 		hwgroup = kmalloc_node(sizeof(*hwgroup), GFP_KERNEL|__GFP_ZERO,
  
@@ -1068,8 +1013,9 @@
 		spin_lock_init(&hwgroup->lock);
  
 		hwif->hwgroup = hwgroup;
-		hwgroup->hwif = hwif->next = hwif;
  
+		hwgroup->port_count = 1;
+
 		init_timer(&hwgroup->timer);
 		hwgroup->timer.function = &ide_timer_expiry;
 		hwgroup->timer.data = (unsigned long) hwgroup;
@@ -1191,29 +1137,6 @@
  
 EXPORT_SYMBOL_GPL(ide_init_disk);
  
-static void ide_remove_drive_from_hwgroup(ide_drive_t *drive)
-{
-	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
-
-	if (drive == drive->next) {
-		/* special case: last drive from hwgroup. */
-		BUG_ON(hwgroup->drive != drive);
-		hwgroup->drive = NULL;
-	} else {
-		ide_drive_t *walk;
-
-		walk = hwgroup->drive;
-		while (walk->next != drive)
-			walk = walk->next;
-		walk->next = drive->next;
-		if (hwgroup->drive == drive) {
-			hwgroup->drive = drive->next;
-			hwgroup->hwif = hwgroup->drive->hwif;
-		}
-	}
-	BUG_ON(hwgroup->drive == drive);
-}
-
 static void drive_release_dev (struct device *dev)
 {
 	ide_drive_t *drive = container_of(dev, ide_drive_t, gendev);
@@ -1222,7 +1145,6 @@
 	ide_proc_unregister_device(drive);
  
 	spin_lock_irq(&hwgroup->lock);
-	ide_remove_drive_from_hwgroup(drive);
 	kfree(drive->id);
 	drive->id = NULL;
 	drive->dev_flags &= ~IDE_DFLAG_PRESENT;
@@ -588,7 +588,6 @@
 	struct request_queue	*queue;	/* request queue */
  
 	struct request		*rq;	/* current request */
-	struct ide_drive_s 	*next;	/* circular list of hwgroup drives */
 	void		*driver_data;	/* extra driver data */
 	u16			*id;	/* identification info */
 #ifdef CONFIG_IDE_PROC_FS
@@ -750,7 +749,6 @@
 struct ide_host;
  
 typedef struct hwif_s {
-	struct hwif_s *next;		/* for linked-list in ide_hwgroup_t */
 	struct hwif_s *mate;		/* other hwif from same PCI chip */
 	struct hwgroup_s *hwgroup;	/* actually (ide_hwgroup_t *) */
 	struct proc_dir_entry *proc;	/* /proc/ide/ directory entry */
@@ -874,9 +872,7 @@
 	unsigned int polling	: 1;
  
 		/* current drive */
-	ide_drive_t *drive;
-		/* ptr to current hwif in linked-list */
-	ide_hwif_t *hwif;
+	ide_drive_t *cur_dev;
  
 		/* current request */
 	struct request *rq;
@@ -892,6 +888,8 @@
 	int req_gen_timer;
  
 	spinlock_t lock;
+
+	int port_count;
 } ide_hwgroup_t;
  
 typedef struct ide_driver_s ide_driver_t;
  
@@ -1622,12 +1620,7 @@
 /*
  * Structure locking:
  *
- * ide_cfg_mtx and hwgroup->lock together protect changes to
- * ide_hwif_t->next
- * ide_drive_t->next
- *
  * ide_hwgroup_t->busy: hwgroup->lock
- * ide_hwgroup_t->hwif: hwgroup->lock
  * ide_hwif_t->{hwgroup,mate}: constant, no locking
  * ide_drive_t->hwif: constant, no locking
  */
...	...	@@ -742,12 +742,12 @@
742	742	* set nIEN for previous port, drives in the
743	743	* quirk_list may not like intr setups/cleanups
744	744	*/
745		- if (prev_port && hwgroup->drive->quirk_list == 0)
	745	+ if (prev_port && hwgroup->cur_dev->quirk_list == 0)
746	746	prev_port->tp_ops->set_irq(prev_port, 0);
747	747
748	748	hwif->host->cur_port = hwif;
749	749	}
750		- hwgroup->drive = drive;
	750	+ hwgroup->cur_dev = drive;
751	751	drive->dev_flags &= ~(IDE_DFLAG_SLEEPING \| IDE_DFLAG_PARKED);
752	752
753	753	spin_unlock_irq(&hwgroup->lock);
754	754
...	...	@@ -913,9 +913,9 @@
913	913	* Either way, we don't really want to complain about anything.
914	914	*/
915	915	} else {
916		- drive = hwgroup->drive;
	916	+ drive = hwgroup->cur_dev;
917	917	if (!drive) {
918		- printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
	918	+ printk(KERN_ERR "%s: ->cur_dev was NULL\n", __func__);
919	919	hwgroup->handler = NULL;
920	920	} else {
921	921	ide_hwif_t *hwif;
...	...	@@ -1033,7 +1033,7 @@
1033	1033	* places
1034	1034	*
1035	1035	* hwif is the interface in the group currently performing
1036		- * a command. hwgroup->drive is the drive and hwgroup->handler is
	1036	+ * a command. hwgroup->cur_dev is the drive and hwgroup->handler is
1037	1037	* the IRQ handler to call. As we issue a command the handlers
1038	1038	* step through multiple states, reassigning the handler to the
1039	1039	* next step in the process. Unlike a smart SCSI controller IDE
...	...	@@ -1105,7 +1105,7 @@
1105	1105	goto out;
1106	1106	}
1107	1107
1108		- drive = hwgroup->drive;
	1108	+ drive = hwgroup->cur_dev;
1109	1109	if (!drive) {
1110	1110	/*
1111	1111	* This should NEVER happen, and there isn't much
...	...	@@ -918,27 +918,9 @@
918	918	return 0;
919	919	}
920	920
921		-static void ide_add_drive_to_hwgroup(ide_drive_t *drive)
922		-{
923		- ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
924		-
925		- spin_lock_irq(&hwgroup->lock);
926		- if (!hwgroup->drive) {
927		- /* first drive for hwgroup. */
928		- drive->next = drive;
929		- hwgroup->drive = drive;
930		- hwgroup->hwif = HWIF(hwgroup->drive);
931		- } else {
932		- drive->next = hwgroup->drive->next;
933		- hwgroup->drive->next = drive;
934		- }
935		- spin_unlock_irq(&hwgroup->lock);
936		-}
937		-
938	921	/*
939	922	* For any present drive:
940	923	* - allocate the block device queue
941		- * - link drive into the hwgroup
942	924	*/
943	925	static int ide_port_setup_devices(ide_hwif_t *hwif)
944	926	{
...	...	@@ -961,8 +943,6 @@
961	943	}
962	944
963	945	j++;
964		-
965		- ide_add_drive_to_hwgroup(drive);
966	946	}
967	947	mutex_unlock(&ide_cfg_mtx);
968	948
969	949
...	...	@@ -978,33 +958,9 @@
978	958	ide_ports[hwif->index] = NULL;
979	959
980	960	spin_lock_irq(&hwgroup->lock);
981		- /*
982		- * Remove us from the hwgroup, and free
983		- * the hwgroup if we were the only member
984		- */
985		- if (hwif->next == hwif) {
986		- BUG_ON(hwgroup->hwif != hwif);
	961	+ /* Free the hwgroup if we were the only member. */
	962	+ if (--hwgroup->port_count == 0)
987	963	kfree(hwgroup);
988		- } else {
989		- /* There is another interface in hwgroup.
990		- * Unlink us, and set hwgroup->drive and ->hwif to
991		- * something sane.
992		- */
993		- ide_hwif_t *g = hwgroup->hwif;
994		-
995		- while (g->next != hwif)
996		- g = g->next;
997		- g->next = hwif->next;
998		- if (hwgroup->hwif == hwif) {
999		- /* Chose a random hwif for hwgroup->hwif.
1000		- * It's guaranteed that there are no drives
1001		- * left in the hwgroup.
1002		- */
1003		- BUG_ON(hwgroup->drive != NULL);
1004		- hwgroup->hwif = g;
1005		- }
1006		- BUG_ON(hwgroup->hwif == hwif);
1007		- }
1008	964	spin_unlock_irq(&hwgroup->lock);
1009	965	}
1010	966
1011	967
...	...	@@ -1044,20 +1000,9 @@
1044	1000	if (match) {
1045	1001	hwgroup = match->hwgroup;
1046	1002	hwif->hwgroup = hwgroup;
1047		- /*
1048		- * Link us into the hwgroup.
1049		- * This must be done early, do ensure that unexpected_intr
1050		- * can find the hwif and prevent irq storms.
1051		- * No drives are attached to the new hwif, choose_drive
1052		- * can't do anything stupid (yet).
1053		- * Add ourself as the 2nd entry to the hwgroup->hwif
1054		- * linked list, the first entry is the hwif that owns
1055		- * hwgroup->handler - do not change that.
1056		- */
	1003	+
1057	1004	spin_lock_irq(&hwgroup->lock);
1058		- hwif->next = hwgroup->hwif->next;
1059		- hwgroup->hwif->next = hwif;
1060		- BUG_ON(hwif->next == hwif);
	1005	+ hwgroup->port_count++;
1061	1006	spin_unlock_irq(&hwgroup->lock);
1062	1007	} else {
1063	1008	hwgroup = kmalloc_node(sizeof(*hwgroup), GFP_KERNEL\|__GFP_ZERO,
1064	1009
...	...	@@ -1068,8 +1013,9 @@
1068	1013	spin_lock_init(&hwgroup->lock);
1069	1014
1070	1015	hwif->hwgroup = hwgroup;
1071		- hwgroup->hwif = hwif->next = hwif;
1072	1016
	1017	+ hwgroup->port_count = 1;
	1018	+
1073	1019	init_timer(&hwgroup->timer);
1074	1020	hwgroup->timer.function = &ide_timer_expiry;
1075	1021	hwgroup->timer.data = (unsigned long) hwgroup;
...	...	@@ -1191,29 +1137,6 @@
1191	1137
1192	1138	EXPORT_SYMBOL_GPL(ide_init_disk);
1193	1139
1194		-static void ide_remove_drive_from_hwgroup(ide_drive_t *drive)
1195		-{
1196		- ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
1197		-
1198		- if (drive == drive->next) {
1199		- /* special case: last drive from hwgroup. */
1200		- BUG_ON(hwgroup->drive != drive);
1201		- hwgroup->drive = NULL;
1202		- } else {
1203		- ide_drive_t *walk;
1204		-
1205		- walk = hwgroup->drive;
1206		- while (walk->next != drive)
1207		- walk = walk->next;
1208		- walk->next = drive->next;
1209		- if (hwgroup->drive == drive) {
1210		- hwgroup->drive = drive->next;
1211		- hwgroup->hwif = hwgroup->drive->hwif;
1212		- }
1213		- }
1214		- BUG_ON(hwgroup->drive == drive);
1215		-}
1216		-
1217	1140	static void drive_release_dev (struct device *dev)
1218	1141	{
1219	1142	ide_drive_t *drive = container_of(dev, ide_drive_t, gendev);
...	...	@@ -1222,7 +1145,6 @@
1222	1145	ide_proc_unregister_device(drive);
1223	1146
1224	1147	spin_lock_irq(&hwgroup->lock);
1225		- ide_remove_drive_from_hwgroup(drive);
1226	1148	kfree(drive->id);
1227	1149	drive->id = NULL;
1228	1150	drive->dev_flags &= ~IDE_DFLAG_PRESENT;
...	...	@@ -588,7 +588,6 @@
588	588	struct request_queue queue; / request queue */
589	589
590	590	struct request rq; / current request */
591		- struct ide_drive_s next; / circular list of hwgroup drives */
592	591	void driver_data; / extra driver data */
593	592	u16 id; / identification info */
594	593	#ifdef CONFIG_IDE_PROC_FS
...	...	@@ -750,7 +749,6 @@
750	749	struct ide_host;
751	750
752	751	typedef struct hwif_s {
753		- struct hwif_s next; / for linked-list in ide_hwgroup_t */
754	752	struct hwif_s mate; / other hwif from same PCI chip */
755	753	struct hwgroup_s hwgroup; / actually (ide_hwgroup_t ) /
756	754	struct proc_dir_entry proc; / /proc/ide/ directory entry */
...	...	@@ -874,9 +872,7 @@
874	872	unsigned int polling : 1;
875	873
876	874	/* current drive */
877		- ide_drive_t *drive;
878		- /* ptr to current hwif in linked-list */
879		- ide_hwif_t *hwif;
	875	+ ide_drive_t *cur_dev;
880	876
881	877	/* current request */
882	878	struct request *rq;
...	...	@@ -892,6 +888,8 @@
892	888	int req_gen_timer;
893	889
894	890	spinlock_t lock;
	891	+
	892	+ int port_count;
895	893	} ide_hwgroup_t;
896	894
897	895	typedef struct ide_driver_s ide_driver_t;
898	896
...	...	@@ -1622,12 +1620,7 @@
1622	1620	/*
1623	1621	* Structure locking:
1624	1622	*
1625		- * ide_cfg_mtx and hwgroup->lock together protect changes to
1626		- * ide_hwif_t->next
1627		- * ide_drive_t->next
1628		- *
1629	1623	* ide_hwgroup_t->busy: hwgroup->lock
1630		- * ide_hwgroup_t->hwif: hwgroup->lock
1631	1624	* ide_hwif_t->{hwgroup,mate}: constant, no locking
1632	1625	* ide_drive_t->hwif: constant, no locking
1633	1626	*/