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-rw-r--r--drivers/char/hvcs.c78
1 files changed, 25 insertions, 53 deletions
diff --git a/drivers/char/hvcs.c b/drivers/char/hvcs.c
index 69d8866de783..fd7559084b82 100644
--- a/drivers/char/hvcs.c
+++ b/drivers/char/hvcs.c
@@ -57,11 +57,7 @@
57 * rescanning partner information upon a user's request. 57 * rescanning partner information upon a user's request.
58 * 58 *
59 * Each vty-server, prior to being exposed to this driver is reference counted 59 * Each vty-server, prior to being exposed to this driver is reference counted
60 * using the 2.6 Linux kernel kobject construct. This kobject is also used by 60 * using the 2.6 Linux kernel kref construct.
61 * the vio bus to provide a vio device sysfs entry that this driver attaches
62 * device specific attributes to, including partner information. The vio bus
63 * framework also provides a sysfs entry for each vio driver. The hvcs driver
64 * provides driver attributes in this entry.
65 * 61 *
66 * For direction on installation and usage of this driver please reference 62 * For direction on installation and usage of this driver please reference
67 * Documentation/powerpc/hvcs.txt. 63 * Documentation/powerpc/hvcs.txt.
@@ -71,7 +67,7 @@
71#include <linux/init.h> 67#include <linux/init.h>
72#include <linux/interrupt.h> 68#include <linux/interrupt.h>
73#include <linux/kernel.h> 69#include <linux/kernel.h>
74#include <linux/kobject.h> 70#include <linux/kref.h>
75#include <linux/kthread.h> 71#include <linux/kthread.h>
76#include <linux/list.h> 72#include <linux/list.h>
77#include <linux/major.h> 73#include <linux/major.h>
@@ -293,12 +289,12 @@ struct hvcs_struct {
293 int chars_in_buffer; 289 int chars_in_buffer;
294 290
295 /* 291 /*
296 * Any variable below the kobject is valid before a tty is connected and 292 * Any variable below the kref is valid before a tty is connected and
297 * stays valid after the tty is disconnected. These shouldn't be 293 * stays valid after the tty is disconnected. These shouldn't be
298 * whacked until the koject refcount reaches zero though some entries 294 * whacked until the koject refcount reaches zero though some entries
299 * may be changed via sysfs initiatives. 295 * may be changed via sysfs initiatives.
300 */ 296 */
301 struct kobject kobj; /* ref count & hvcs_struct lifetime */ 297 struct kref kref; /* ref count & hvcs_struct lifetime */
302 int connected; /* is the vty-server currently connected to a vty? */ 298 int connected; /* is the vty-server currently connected to a vty? */
303 uint32_t p_unit_address; /* partner unit address */ 299 uint32_t p_unit_address; /* partner unit address */
304 uint32_t p_partition_ID; /* partner partition ID */ 300 uint32_t p_partition_ID; /* partner partition ID */
@@ -307,8 +303,8 @@ struct hvcs_struct {
307 struct vio_dev *vdev; 303 struct vio_dev *vdev;
308}; 304};
309 305
310/* Required to back map a kobject to its containing object */ 306/* Required to back map a kref to its containing object */
311#define from_kobj(kobj) container_of(kobj, struct hvcs_struct, kobj) 307#define from_kref(k) container_of(k, struct hvcs_struct, kref)
312 308
313static struct list_head hvcs_structs = LIST_HEAD_INIT(hvcs_structs); 309static struct list_head hvcs_structs = LIST_HEAD_INIT(hvcs_structs);
314static DEFINE_SPINLOCK(hvcs_structs_lock); 310static DEFINE_SPINLOCK(hvcs_structs_lock);
@@ -334,7 +330,6 @@ static void hvcs_partner_free(struct hvcs_struct *hvcsd);
334static int hvcs_enable_device(struct hvcs_struct *hvcsd, 330static int hvcs_enable_device(struct hvcs_struct *hvcsd,
335 uint32_t unit_address, unsigned int irq, struct vio_dev *dev); 331 uint32_t unit_address, unsigned int irq, struct vio_dev *dev);
336 332
337static void destroy_hvcs_struct(struct kobject *kobj);
338static int hvcs_open(struct tty_struct *tty, struct file *filp); 333static int hvcs_open(struct tty_struct *tty, struct file *filp);
339static void hvcs_close(struct tty_struct *tty, struct file *filp); 334static void hvcs_close(struct tty_struct *tty, struct file *filp);
340static void hvcs_hangup(struct tty_struct * tty); 335static void hvcs_hangup(struct tty_struct * tty);
@@ -703,10 +698,10 @@ static void hvcs_return_index(int index)
703 hvcs_index_list[index] = -1; 698 hvcs_index_list[index] = -1;
704} 699}
705 700
706/* callback when the kboject ref count reaches zero */ 701/* callback when the kref ref count reaches zero */
707static void destroy_hvcs_struct(struct kobject *kobj) 702static void destroy_hvcs_struct(struct kref *kref)
708{ 703{
709 struct hvcs_struct *hvcsd = from_kobj(kobj); 704 struct hvcs_struct *hvcsd = from_kref(kref);
710 struct vio_dev *vdev; 705 struct vio_dev *vdev;
711 unsigned long flags; 706 unsigned long flags;
712 707
@@ -743,10 +738,6 @@ static void destroy_hvcs_struct(struct kobject *kobj)
743 kfree(hvcsd); 738 kfree(hvcsd);
744} 739}
745 740
746static struct kobj_type hvcs_kobj_type = {
747 .release = destroy_hvcs_struct,
748};
749
750static int hvcs_get_index(void) 741static int hvcs_get_index(void)
751{ 742{
752 int i; 743 int i;
@@ -791,9 +782,7 @@ static int __devinit hvcs_probe(
791 782
792 spin_lock_init(&hvcsd->lock); 783 spin_lock_init(&hvcsd->lock);
793 /* Automatically incs the refcount the first time */ 784 /* Automatically incs the refcount the first time */
794 kobject_init(&hvcsd->kobj); 785 kref_init(&hvcsd->kref);
795 /* Set up the callback for terminating the hvcs_struct's life */
796 hvcsd->kobj.ktype = &hvcs_kobj_type;
797 786
798 hvcsd->vdev = dev; 787 hvcsd->vdev = dev;
799 dev->dev.driver_data = hvcsd; 788 dev->dev.driver_data = hvcsd;
@@ -844,7 +833,6 @@ static int __devexit hvcs_remove(struct vio_dev *dev)
844{ 833{
845 struct hvcs_struct *hvcsd = dev->dev.driver_data; 834 struct hvcs_struct *hvcsd = dev->dev.driver_data;
846 unsigned long flags; 835 unsigned long flags;
847 struct kobject *kobjp;
848 struct tty_struct *tty; 836 struct tty_struct *tty;
849 837
850 if (!hvcsd) 838 if (!hvcsd)
@@ -856,15 +844,13 @@ static int __devexit hvcs_remove(struct vio_dev *dev)
856 844
857 tty = hvcsd->tty; 845 tty = hvcsd->tty;
858 846
859 kobjp = &hvcsd->kobj;
860
861 spin_unlock_irqrestore(&hvcsd->lock, flags); 847 spin_unlock_irqrestore(&hvcsd->lock, flags);
862 848
863 /* 849 /*
864 * Let the last holder of this object cause it to be removed, which 850 * Let the last holder of this object cause it to be removed, which
865 * would probably be tty_hangup below. 851 * would probably be tty_hangup below.
866 */ 852 */
867 kobject_put (kobjp); 853 kref_put(&hvcsd->kref, destroy_hvcs_struct);
868 854
869 /* 855 /*
870 * The hangup is a scheduled function which will auto chain call 856 * The hangup is a scheduled function which will auto chain call
@@ -1086,7 +1072,7 @@ static int hvcs_enable_device(struct hvcs_struct *hvcsd, uint32_t unit_address,
1086} 1072}
1087 1073
1088/* 1074/*
1089 * This always increments the kobject ref count if the call is successful. 1075 * This always increments the kref ref count if the call is successful.
1090 * Please remember to dec when you are done with the instance. 1076 * Please remember to dec when you are done with the instance.
1091 * 1077 *
1092 * NOTICE: Do NOT hold either the hvcs_struct.lock or hvcs_structs_lock when 1078 * NOTICE: Do NOT hold either the hvcs_struct.lock or hvcs_structs_lock when
@@ -1103,7 +1089,7 @@ static struct hvcs_struct *hvcs_get_by_index(int index)
1103 list_for_each_entry(hvcsd, &hvcs_structs, next) { 1089 list_for_each_entry(hvcsd, &hvcs_structs, next) {
1104 spin_lock_irqsave(&hvcsd->lock, flags); 1090 spin_lock_irqsave(&hvcsd->lock, flags);
1105 if (hvcsd->index == index) { 1091 if (hvcsd->index == index) {
1106 kobject_get(&hvcsd->kobj); 1092 kref_get(&hvcsd->kref);
1107 spin_unlock_irqrestore(&hvcsd->lock, flags); 1093 spin_unlock_irqrestore(&hvcsd->lock, flags);
1108 spin_unlock(&hvcs_structs_lock); 1094 spin_unlock(&hvcs_structs_lock);
1109 return hvcsd; 1095 return hvcsd;
@@ -1129,14 +1115,13 @@ static int hvcs_open(struct tty_struct *tty, struct file *filp)
1129 unsigned int irq; 1115 unsigned int irq;
1130 struct vio_dev *vdev; 1116 struct vio_dev *vdev;
1131 unsigned long unit_address; 1117 unsigned long unit_address;
1132 struct kobject *kobjp;
1133 1118
1134 if (tty->driver_data) 1119 if (tty->driver_data)
1135 goto fast_open; 1120 goto fast_open;
1136 1121
1137 /* 1122 /*
1138 * Is there a vty-server that shares the same index? 1123 * Is there a vty-server that shares the same index?
1139 * This function increments the kobject index. 1124 * This function increments the kref index.
1140 */ 1125 */
1141 if (!(hvcsd = hvcs_get_by_index(tty->index))) { 1126 if (!(hvcsd = hvcs_get_by_index(tty->index))) {
1142 printk(KERN_WARNING "HVCS: open failed, no device associated" 1127 printk(KERN_WARNING "HVCS: open failed, no device associated"
@@ -1181,7 +1166,7 @@ static int hvcs_open(struct tty_struct *tty, struct file *filp)
1181 * and will grab the spinlock and free the connection if it fails. 1166 * and will grab the spinlock and free the connection if it fails.
1182 */ 1167 */
1183 if (((rc = hvcs_enable_device(hvcsd, unit_address, irq, vdev)))) { 1168 if (((rc = hvcs_enable_device(hvcsd, unit_address, irq, vdev)))) {
1184 kobject_put(&hvcsd->kobj); 1169 kref_put(&hvcsd->kref, destroy_hvcs_struct);
1185 printk(KERN_WARNING "HVCS: enable device failed.\n"); 1170 printk(KERN_WARNING "HVCS: enable device failed.\n");
1186 return rc; 1171 return rc;
1187 } 1172 }
@@ -1192,17 +1177,11 @@ fast_open:
1192 hvcsd = tty->driver_data; 1177 hvcsd = tty->driver_data;
1193 1178
1194 spin_lock_irqsave(&hvcsd->lock, flags); 1179 spin_lock_irqsave(&hvcsd->lock, flags);
1195 if (!kobject_get(&hvcsd->kobj)) { 1180 kref_get(&hvcsd->kref);
1196 spin_unlock_irqrestore(&hvcsd->lock, flags);
1197 printk(KERN_ERR "HVCS: Kobject of open"
1198 " hvcs doesn't exist.\n");
1199 return -EFAULT; /* Is this the right return value? */
1200 }
1201
1202 hvcsd->open_count++; 1181 hvcsd->open_count++;
1203
1204 hvcsd->todo_mask |= HVCS_SCHED_READ; 1182 hvcsd->todo_mask |= HVCS_SCHED_READ;
1205 spin_unlock_irqrestore(&hvcsd->lock, flags); 1183 spin_unlock_irqrestore(&hvcsd->lock, flags);
1184
1206open_success: 1185open_success:
1207 hvcs_kick(); 1186 hvcs_kick();
1208 1187
@@ -1212,9 +1191,8 @@ open_success:
1212 return 0; 1191 return 0;
1213 1192
1214error_release: 1193error_release:
1215 kobjp = &hvcsd->kobj;
1216 spin_unlock_irqrestore(&hvcsd->lock, flags); 1194 spin_unlock_irqrestore(&hvcsd->lock, flags);
1217 kobject_put(&hvcsd->kobj); 1195 kref_put(&hvcsd->kref, destroy_hvcs_struct);
1218 1196
1219 printk(KERN_WARNING "HVCS: partner connect failed.\n"); 1197 printk(KERN_WARNING "HVCS: partner connect failed.\n");
1220 return retval; 1198 return retval;
@@ -1224,7 +1202,6 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
1224{ 1202{
1225 struct hvcs_struct *hvcsd; 1203 struct hvcs_struct *hvcsd;
1226 unsigned long flags; 1204 unsigned long flags;
1227 struct kobject *kobjp;
1228 int irq = NO_IRQ; 1205 int irq = NO_IRQ;
1229 1206
1230 /* 1207 /*
@@ -1245,7 +1222,6 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
1245 hvcsd = tty->driver_data; 1222 hvcsd = tty->driver_data;
1246 1223
1247 spin_lock_irqsave(&hvcsd->lock, flags); 1224 spin_lock_irqsave(&hvcsd->lock, flags);
1248 kobjp = &hvcsd->kobj;
1249 if (--hvcsd->open_count == 0) { 1225 if (--hvcsd->open_count == 0) {
1250 1226
1251 vio_disable_interrupts(hvcsd->vdev); 1227 vio_disable_interrupts(hvcsd->vdev);
@@ -1270,7 +1246,7 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
1270 tty->driver_data = NULL; 1246 tty->driver_data = NULL;
1271 1247
1272 free_irq(irq, hvcsd); 1248 free_irq(irq, hvcsd);
1273 kobject_put(kobjp); 1249 kref_put(&hvcsd->kref, destroy_hvcs_struct);
1274 return; 1250 return;
1275 } else if (hvcsd->open_count < 0) { 1251 } else if (hvcsd->open_count < 0) {
1276 printk(KERN_ERR "HVCS: vty-server@%X open_count: %d" 1252 printk(KERN_ERR "HVCS: vty-server@%X open_count: %d"
@@ -1279,7 +1255,7 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
1279 } 1255 }
1280 1256
1281 spin_unlock_irqrestore(&hvcsd->lock, flags); 1257 spin_unlock_irqrestore(&hvcsd->lock, flags);
1282 kobject_put(kobjp); 1258 kref_put(&hvcsd->kref, destroy_hvcs_struct);
1283} 1259}
1284 1260
1285static void hvcs_hangup(struct tty_struct * tty) 1261static void hvcs_hangup(struct tty_struct * tty)
@@ -1287,21 +1263,17 @@ static void hvcs_hangup(struct tty_struct * tty)
1287 struct hvcs_struct *hvcsd = tty->driver_data; 1263 struct hvcs_struct *hvcsd = tty->driver_data;
1288 unsigned long flags; 1264 unsigned long flags;
1289 int temp_open_count; 1265 int temp_open_count;
1290 struct kobject *kobjp;
1291 int irq = NO_IRQ; 1266 int irq = NO_IRQ;
1292 1267
1293 spin_lock_irqsave(&hvcsd->lock, flags); 1268 spin_lock_irqsave(&hvcsd->lock, flags);
1294 /* Preserve this so that we know how many kobject refs to put */ 1269 /* Preserve this so that we know how many kref refs to put */
1295 temp_open_count = hvcsd->open_count; 1270 temp_open_count = hvcsd->open_count;
1296 1271
1297 /* 1272 /*
1298 * Don't kobject put inside the spinlock because the destruction 1273 * Don't kref put inside the spinlock because the destruction
1299 * callback may use the spinlock and it may get called before the 1274 * callback may use the spinlock and it may get called before the
1300 * spinlock has been released. Get a pointer to the kobject and 1275 * spinlock has been released.
1301 * kobject_put on that after releasing the spinlock.
1302 */ 1276 */
1303 kobjp = &hvcsd->kobj;
1304
1305 vio_disable_interrupts(hvcsd->vdev); 1277 vio_disable_interrupts(hvcsd->vdev);
1306 1278
1307 hvcsd->todo_mask = 0; 1279 hvcsd->todo_mask = 0;
@@ -1324,7 +1296,7 @@ static void hvcs_hangup(struct tty_struct * tty)
1324 free_irq(irq, hvcsd); 1296 free_irq(irq, hvcsd);
1325 1297
1326 /* 1298 /*
1327 * We need to kobject_put() for every open_count we have since the 1299 * We need to kref_put() for every open_count we have since the
1328 * tty_hangup() function doesn't invoke a close per open connection on a 1300 * tty_hangup() function doesn't invoke a close per open connection on a
1329 * non-console device. 1301 * non-console device.
1330 */ 1302 */
@@ -1335,7 +1307,7 @@ static void hvcs_hangup(struct tty_struct * tty)
1335 * NOTE: If this hangup was signaled from user space then the 1307 * NOTE: If this hangup was signaled from user space then the
1336 * final put will never happen. 1308 * final put will never happen.
1337 */ 1309 */
1338 kobject_put(kobjp); 1310 kref_put(&hvcsd->kref, destroy_hvcs_struct);
1339 } 1311 }
1340} 1312}
1341 1313