[PATCH] w1: Use mutexes instead of semaphores.

Use mutexes instead of semaphores.
Patch tested on x86_64 and i386 with test bus master driver.

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

8 files changed, 70 insertions, 127 deletions

diff --git a/drivers/w1/masters/ds2482.c b/drivers/w1/masters/ds2482.c
index d1cacd23576b..af492cc48db2 100644
--- a/drivers/w1/masters/ds2482.c
+++ b/drivers/w1/masters/ds2482.c
@@ -125,7 +125,7 @@ struct ds2482_w1_chan {
 
 struct ds2482_data {
         struct i2c_client       client;
-        struct semaphore        access_lock;
+        struct mutex            access_lock;
 
         /* 1-wire interface(s) */
         int                     w1_count;       /* 1 or 8 */
@@ -265,7 +265,7 @@ static u8 ds2482_w1_touch_bit(void *data, u8 bit)
         struct ds2482_data    *pdev = pchan->pdev;
         int status = -1;
 
-        down(&pdev->access_lock);
+        mutex_lock(&pdev->access_lock);
 
         /* Select the channel */
         ds2482_wait_1wire_idle(pdev);
@@ -277,7 +277,7 @@ static u8 ds2482_w1_touch_bit(void *data, u8 bit)
                                   bit ? 0xFF : 0))
                 status = ds2482_wait_1wire_idle(pdev);
 
-        up(&pdev->access_lock);
+        mutex_unlock(&pdev->access_lock);
 
         return (status & DS2482_REG_STS_SBR) ? 1 : 0;
 }
@@ -297,7 +297,7 @@ static u8 ds2482_w1_triplet(void *data, u8 dbit)
         struct ds2482_data    *pdev = pchan->pdev;
         int status = (3 << 5);
 
-        down(&pdev->access_lock);
+        mutex_lock(&pdev->access_lock);
 
         /* Select the channel */
         ds2482_wait_1wire_idle(pdev);
@@ -309,7 +309,7 @@ static u8 ds2482_w1_triplet(void *data, u8 dbit)
                                   dbit ? 0xFF : 0))
                 status = ds2482_wait_1wire_idle(pdev);
 
-        up(&pdev->access_lock);
+        mutex_unlock(&pdev->access_lock);
 
         /* Decode the status */
         return (status >> 5);
@@ -326,7 +326,7 @@ static void ds2482_w1_write_byte(void *data, u8 byte)
         struct ds2482_w1_chan *pchan = data;
         struct ds2482_data    *pdev = pchan->pdev;
 
-        down(&pdev->access_lock);
+        mutex_lock(&pdev->access_lock);
 
         /* Select the channel */
         ds2482_wait_1wire_idle(pdev);
@@ -336,7 +336,7 @@ static void ds2482_w1_write_byte(void *data, u8 byte)
         /* Send the write byte command */
         ds2482_send_cmd_data(pdev, DS2482_CMD_1WIRE_WRITE_BYTE, byte);
 
-        up(&pdev->access_lock);
+        mutex_unlock(&pdev->access_lock);
 }
 
 /**
@@ -351,7 +351,7 @@ static u8 ds2482_w1_read_byte(void *data)
         struct ds2482_data    *pdev = pchan->pdev;
         int result;
 
-        down(&pdev->access_lock);
+        mutex_lock(&pdev->access_lock);
 
         /* Select the channel */
         ds2482_wait_1wire_idle(pdev);
@@ -370,7 +370,7 @@ static u8 ds2482_w1_read_byte(void *data)
         /* Read the data byte */
         result = i2c_smbus_read_byte(&pdev->client);
 
-        up(&pdev->access_lock);
+        mutex_unlock(&pdev->access_lock);
 
         return result;
 }
@@ -389,7 +389,7 @@ static u8 ds2482_w1_reset_bus(void *data)
         int err;
         u8 retval = 1;
 
-        down(&pdev->access_lock);
+        mutex_lock(&pdev->access_lock);
 
         /* Select the channel */
         ds2482_wait_1wire_idle(pdev);
@@ -409,7 +409,7 @@ static u8 ds2482_w1_reset_bus(void *data)
                                              0xF0);
         }
 
-        up(&pdev->access_lock);
+        mutex_unlock(&pdev->access_lock);
 
         return retval;
 }
@@ -482,7 +482,7 @@ static int ds2482_detect(struct i2c_adapter *adapter, int address, int kind)
         snprintf(new_client->name, sizeof(new_client->name), "ds2482-%d00",
                  data->w1_count);
 
-        init_MUTEX(&data->access_lock);
+        mutex_init(&data->access_lock);
 
         /* Tell the I2C layer a new client has arrived */
         if ((err = i2c_attach_client(new_client)))
diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c
index 637677833da5..299e274d241a 100644
--- a/drivers/w1/masters/ds2490.c
+++ b/drivers/w1/masters/ds2490.c
@@ -169,7 +169,7 @@ static int ds_send_control(struct ds_device *, u16, u16);
 static int ds_send_control_cmd(struct ds_device *, u16, u16);
 
 static LIST_HEAD(ds_devices);
-static DECLARE_MUTEX(ds_mutex);
+static DEFINE_MUTEX(ds_mutex);
 
 static struct usb_driver ds_driver = {
         .name =         "DS9490R",
@@ -887,9 +887,9 @@ static int ds_probe(struct usb_interface *intf,
         if (err)
                 goto err_out_clear;
 
-        down(&ds_mutex);
+        mutex_lock(&ds_mutex);
         list_add_tail(&dev->ds_entry, &ds_devices);
-        up(&ds_mutex);
+        mutex_unlock(&ds_mutex);
 
         return 0;
 
@@ -909,9 +909,9 @@ static void ds_disconnect(struct usb_interface *intf)
         if (!dev)
                 return;
 
-        down(&ds_mutex);
+        mutex_lock(&ds_mutex);
         list_del(&dev->ds_entry);
-        up(&ds_mutex);
+        mutex_unlock(&ds_mutex);
 
         ds_w1_fini(dev);
 
diff --git a/drivers/w1/slaves/w1_ds2433.c b/drivers/w1/slaves/w1_ds2433.c
index ddd01e6fc2c9..2ac238f1480e 100644
--- a/drivers/w1/slaves/w1_ds2433.c
+++ b/drivers/w1/slaves/w1_ds2433.c
@@ -105,11 +105,7 @@ static ssize_t w1_f23_read_bin(struct kobject *kobj, char *buf, loff_t off,
         if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
                 return 0;
 
-        atomic_inc(&sl->refcnt);
-        if (down_interruptible(&sl->master->mutex)) {
-                count = 0;
-                goto out_dec;
-        }
+        mutex_lock(&sl->master->mutex);
 
 #ifdef CONFIG_W1_F23_CRC
 
@@ -140,9 +136,7 @@ static ssize_t w1_f23_read_bin(struct kobject *kobj, char *buf, loff_t off,
 #endif  /* CONFIG_W1_F23_CRC */
 
 out_up:
-        up(&sl->master->mutex);
-out_dec:
-        atomic_dec(&sl->refcnt);
+        mutex_unlock(&sl->master->mutex);
 
         return count;
 }
@@ -231,11 +225,7 @@ static ssize_t w1_f23_write_bin(struct kobject *kobj, char *buf, loff_t off,
         }
 #endif  /* CONFIG_W1_F23_CRC */
 
-        atomic_inc(&sl->refcnt);
-        if (down_interruptible(&sl->master->mutex)) {
-                count = 0;
-                goto out_dec;
-        }
+        mutex_lock(&sl->master->mutex);
 
         /* Can only write data to one page at a time */
         idx = 0;
@@ -253,9 +243,7 @@ static ssize_t w1_f23_write_bin(struct kobject *kobj, char *buf, loff_t off,
         }
 
 out_up:
-        up(&sl->master->mutex);
-out_dec:
-        atomic_dec(&sl->refcnt);
+        mutex_unlock(&sl->master->mutex);
 
         return count;
 }
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index 44afdffe3c8b..5372cfcbd054 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -165,12 +165,7 @@ static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, si
         u8 rom[9], crc, verdict;
         int i, max_trying = 10;
 
-        atomic_inc(&sl->refcnt);
-        smp_mb__after_atomic_inc();
-        if (down_interruptible(&sl->master->mutex)) {
-                count = 0;
-                goto out_dec;
-        }
+        mutex_lock(&sl->master->mutex);
 
         if (off > W1_SLAVE_DATA_SIZE) {
                 count = 0;
@@ -233,10 +228,7 @@ static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, si
 
         count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid));
 out:
-        up(&dev->mutex);
-out_dec:
-        smp_mb__before_atomic_inc();
-        atomic_dec(&sl->refcnt);
+        mutex_unlock(&dev->mutex);
 
         return count;
 }
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index 32d8de881f11..420be14c2f8e 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -54,7 +54,7 @@ module_param_named(control_timeout, w1_control_timeout, int, 0);
 module_param_named(max_slave_count, w1_max_slave_count, int, 0);
 module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
 
-DECLARE_MUTEX(w1_mlock);
+DEFINE_MUTEX(w1_mlock);
 LIST_HEAD(w1_masters);
 
 static struct task_struct *w1_control_thread;
@@ -139,11 +139,7 @@ static ssize_t w1_default_write(struct kobject *kobj, char *buf, loff_t off, siz
 {
         struct w1_slave *sl = kobj_to_w1_slave(kobj);
 
-        if (down_interruptible(&sl->master->mutex)) {
-                count = 0;
-                goto out;
-        }
-
+        mutex_lock(&sl->master->mutex);
         if (w1_reset_select_slave(sl)) {
                 count = 0;
                 goto out_up;
@@ -152,8 +148,7 @@ static ssize_t w1_default_write(struct kobject *kobj, char *buf, loff_t off, siz
         w1_write_block(sl->master, buf, count);
 
 out_up:
-        up(&sl->master->mutex);
-out:
+        mutex_unlock(&sl->master->mutex);
         return count;
 }
 
@@ -161,15 +156,9 @@ static ssize_t w1_default_read(struct kobject *kobj, char *buf, loff_t off, size
 {
         struct w1_slave *sl = kobj_to_w1_slave(kobj);
 
-        if (down_interruptible(&sl->master->mutex)) {
-                count = 0;
-                goto out;
-        }
-
+        mutex_lock(&sl->master->mutex);
         w1_read_block(sl->master, buf, count);
-
-        up(&sl->master->mutex);
-out:
+        mutex_unlock(&sl->master->mutex);
         return count;
 }
 
@@ -243,12 +232,9 @@ static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_a
         struct w1_master *md = dev_to_w1_master(dev);
         ssize_t count;
 
-        if (down_interruptible (&md->mutex))
-                return -EBUSY;
-
+        mutex_lock(&md->mutex);
         count = sprintf(buf, "%s\n", md->name);
-
-        up(&md->mutex);
+        mutex_unlock(&md->mutex);
 
         return count;
 }
@@ -259,12 +245,9 @@ static ssize_t w1_master_attribute_store_search(struct device * dev,
 {
         struct w1_master *md = dev_to_w1_master(dev);
 
-        if (down_interruptible (&md->mutex))
-                return -EBUSY;
-
+        mutex_lock(&md->mutex);
         md->search_count = simple_strtol(buf, NULL, 0);
-
-        up(&md->mutex);
+        mutex_unlock(&md->mutex);
 
         return count;
 }
@@ -276,12 +259,9 @@ static ssize_t w1_master_attribute_show_search(struct device *dev,
         struct w1_master *md = dev_to_w1_master(dev);
         ssize_t count;
 
-        if (down_interruptible (&md->mutex))
-                return -EBUSY;
-
+        mutex_lock(&md->mutex);
         count = sprintf(buf, "%d\n", md->search_count);
-
-        up(&md->mutex);
+        mutex_unlock(&md->mutex);
 
         return count;
 }
@@ -291,12 +271,9 @@ static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct devic
         struct w1_master *md = dev_to_w1_master(dev);
         ssize_t count;
 
-        if (down_interruptible(&md->mutex))
-                return -EBUSY;
-
+        mutex_lock(&md->mutex);
         count = sprintf(buf, "0x%p\n", md->bus_master);
-
-        up(&md->mutex);
+        mutex_unlock(&md->mutex);
         return count;
 }
 
@@ -312,12 +289,9 @@ static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, stru
         struct w1_master *md = dev_to_w1_master(dev);
         ssize_t count;
 
-        if (down_interruptible(&md->mutex))
-                return -EBUSY;
-
+        mutex_lock(&md->mutex);
         count = sprintf(buf, "%d\n", md->max_slave_count);
-
-        up(&md->mutex);
+        mutex_unlock(&md->mutex);
         return count;
 }
 
@@ -326,12 +300,9 @@ static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct devi
         struct w1_master *md = dev_to_w1_master(dev);
         ssize_t count;
 
-        if (down_interruptible(&md->mutex))
-                return -EBUSY;
-
+        mutex_lock(&md->mutex);
         count = sprintf(buf, "%lu\n", md->attempts);
-
-        up(&md->mutex);
+        mutex_unlock(&md->mutex);
         return count;
 }
 
@@ -340,12 +311,9 @@ static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct d
         struct w1_master *md = dev_to_w1_master(dev);
         ssize_t count;
 
-        if (down_interruptible(&md->mutex))
-                return -EBUSY;
-
+        mutex_lock(&md->mutex);
         count = sprintf(buf, "%d\n", md->slave_count);
-
-        up(&md->mutex);
+        mutex_unlock(&md->mutex);
         return count;
 }
 
@@ -354,8 +322,7 @@ static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device
         struct w1_master *md = dev_to_w1_master(dev);
         int c = PAGE_SIZE;
 
-        if (down_interruptible(&md->mutex))
-                return -EBUSY;
+        mutex_lock(&md->mutex);
 
         if (md->slave_count == 0)
                 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
@@ -370,7 +337,7 @@ static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device
                 }
         }
 
-        up(&md->mutex);
+        mutex_unlock(&md->mutex);
 
         return PAGE_SIZE - c;
 }
@@ -620,7 +587,7 @@ static struct w1_master *w1_search_master(void *data)
         struct w1_master *dev;
         int found = 0;
 
-        down(&w1_mlock);
+        mutex_lock(&w1_mlock);
         list_for_each_entry(dev, &w1_masters, w1_master_entry) {
                 if (dev->bus_master->data == data) {
                         found = 1;
@@ -628,7 +595,7 @@ static struct w1_master *w1_search_master(void *data)
                         break;
                 }
         }
-        up(&w1_mlock);
+        mutex_unlock(&w1_mlock);
 
         return (found)?dev:NULL;
 }
@@ -638,7 +605,7 @@ struct w1_master *w1_search_master_id(u32 id)
         struct w1_master *dev;
         int found = 0;
 
-        down(&w1_mlock);
+        mutex_lock(&w1_mlock);
         list_for_each_entry(dev, &w1_masters, w1_master_entry) {
                 if (dev->id == id) {
                         found = 1;
@@ -646,7 +613,7 @@ struct w1_master *w1_search_master_id(u32 id)
                         break;
                 }
         }
-        up(&w1_mlock);
+        mutex_unlock(&w1_mlock);
 
         return (found)?dev:NULL;
 }
@@ -657,9 +624,9 @@ struct w1_slave *w1_search_slave(struct w1_reg_num *id)
         struct w1_slave *sl = NULL;
         int found = 0;
 
-        down(&w1_mlock);
+        mutex_lock(&w1_mlock);
         list_for_each_entry(dev, &w1_masters, w1_master_entry) {
-                down(&dev->mutex);
+                mutex_lock(&dev->mutex);
                 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
                         if (sl->reg_num.family == id->family &&
                                         sl->reg_num.id == id->id &&
@@ -670,12 +637,12 @@ struct w1_slave *w1_search_slave(struct w1_reg_num *id)
                                 break;
                         }
                 }
-                up(&dev->mutex);
+                mutex_unlock(&dev->mutex);
 
                 if (found)
                         break;
         }
-        up(&w1_mlock);
+        mutex_unlock(&w1_mlock);
 
         return (found)?sl:NULL;
 }
@@ -684,13 +651,13 @@ void w1_reconnect_slaves(struct w1_family *f)
 {
         struct w1_master *dev;
 
-        down(&w1_mlock);
+        mutex_lock(&w1_mlock);
         list_for_each_entry(dev, &w1_masters, w1_master_entry) {
                 dev_dbg(&dev->dev, "Reconnecting slaves in %s into new family %02x.\n",
                                 dev->name, f->fid);
                 set_bit(W1_MASTER_NEED_RECONNECT, &dev->flags);
         }
-        up(&w1_mlock);
+        mutex_unlock(&w1_mlock);
 }
 
 static void w1_slave_found(void *data, u64 rn)
@@ -845,23 +812,23 @@ static int w1_control(void *data)
                         if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
                                 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
 
-                                down(&w1_mlock);
+                                mutex_lock(&w1_mlock);
                                 list_del(&dev->w1_master_entry);
-                                up(&w1_mlock);
+                                mutex_unlock(&w1_mlock);
 
-                                down(&dev->mutex);
+                                mutex_lock(&dev->mutex);
                                 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
                                         w1_slave_detach(sl);
                                 }
                                 w1_destroy_master_attributes(dev);
-                                up(&dev->mutex);
+                                mutex_unlock(&dev->mutex);
                                 atomic_dec(&dev->refcnt);
                                 continue;
                         }
 
                         if (test_bit(W1_MASTER_NEED_RECONNECT, &dev->flags)) {
                                 dev_dbg(&dev->dev, "Reconnecting slaves in device %s.\n", dev->name);
-                                down(&dev->mutex);
+                                mutex_lock(&dev->mutex);
                                 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
                                         if (sl->family->fid == W1_FAMILY_DEFAULT) {
                                                 struct w1_reg_num rn;
@@ -874,7 +841,7 @@ static int w1_control(void *data)
                                 }
                                 dev_dbg(&dev->dev, "Reconnecting slaves in device %s has been finished.\n", dev->name);
                                 clear_bit(W1_MASTER_NEED_RECONNECT, &dev->flags);
-                                up(&dev->mutex);
+                                mutex_unlock(&dev->mutex);
                         }
                 }
         }
@@ -921,12 +888,9 @@ int w1_process(void *data)
                 if (dev->search_count == 0)
                         continue;
 
-                if (down_interruptible(&dev->mutex))
-                        continue;
-
+                mutex_lock(&dev->mutex);
                 w1_search_process(dev, W1_SEARCH);
-
-                up(&dev->mutex);
+                mutex_unlock(&dev->mutex);
         }
 
         atomic_dec(&dev->refcnt);
diff --git a/drivers/w1/w1.h b/drivers/w1/w1.h
index e8c96e6e7418..6caccfc97cdf 100644
--- a/drivers/w1/w1.h
+++ b/drivers/w1/w1.h
@@ -41,8 +41,7 @@ struct w1_reg_num
 
 #include <linux/completion.h>
 #include <linux/device.h>
-
-#include <asm/semaphore.h>
+#include <linux/mutex.h>
 
 #include "w1_family.h"
 
@@ -171,7 +170,7 @@ struct w1_master
         long                    flags;
 
         struct task_struct      *thread;
-        struct semaphore        mutex;
+        struct mutex            mutex;
 
         struct device_driver    *driver;
         struct device           dev;
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index ae78473d11f9..24e7c102fa75 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -36,7 +36,7 @@ extern struct device w1_master_device;
 extern int w1_max_slave_count;
 extern int w1_max_slave_ttl;
 extern struct list_head w1_masters;
-extern struct semaphore w1_mlock;
+extern struct mutex w1_mlock;
 
 extern int w1_process(void *);
 
@@ -74,7 +74,7 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
         atomic_set(&dev->refcnt, 2);
 
         INIT_LIST_HEAD(&dev->slist);
-        init_MUTEX(&dev->mutex);
+        mutex_init(&dev->mutex);
 
         memcpy(&dev->dev, device, sizeof(struct device));
         snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id),
@@ -135,9 +135,9 @@ int w1_add_master_device(struct w1_bus_master *master)
 
         dev->initialized = 1;
 
-        down(&w1_mlock);
+        mutex_lock(&w1_mlock);
         list_add(&dev->w1_master_entry, &w1_masters);
-        up(&w1_mlock);
+        mutex_unlock(&w1_mlock);
 
         memset(&msg, 0, sizeof(msg));
         msg.id.mst.id = dev->id;
diff --git a/drivers/w1/w1_netlink.c b/drivers/w1/w1_netlink.c
index d539e09aad37..65c5ebd0787e 100644
--- a/drivers/w1/w1_netlink.c
+++ b/drivers/w1/w1_netlink.c
@@ -171,7 +171,7 @@ static void w1_cn_callback(void *data)
                         goto out_cont;
                 }
 
-                down(&dev->mutex);
+                mutex_lock(&dev->mutex);
 
                 if (sl && w1_reset_select_slave(sl)) {
                         err = -ENODEV;
@@ -198,7 +198,7 @@ out_up:
                 atomic_dec(&dev->refcnt);
                 if (sl)
                         atomic_dec(&sl->refcnt);
-                up(&dev->mutex);
+                mutex_unlock(&dev->mutex);
 out_cont:
                 msg->len -= sizeof(struct w1_netlink_msg) + m->len;
                 m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);