[PATCH 34/49] pcmcia: simplify locking
Dominik Brodowski
linux at dominikbrodowski.net
Sat Feb 27 05:42:29 EST 2010
replace pcmcia_socket->lock and pcmcia_dev_list_lock by using the
per-socket "ops_mutex", as we do neither need different locks
nor a spinlock here.
Tested-by: Wolfram Sang <w.sang at pengutronix.de>
Signed-off-by: Dominik Brodowski <linux at dominikbrodowski.net>
---
drivers/pcmcia/cs.c | 2 -
drivers/pcmcia/cs_internal.h | 2 -
drivers/pcmcia/ds.c | 70 ++++++++++++++++-------------------------
drivers/pcmcia/pcmcia_ioctl.c | 36 +++++++++------------
drivers/pcmcia/rsrc_mgr.c | 6 +--
drivers/pcmcia/socket_sysfs.c | 5 +--
include/pcmcia/ss.h | 7 ++--
7 files changed, 51 insertions(+), 77 deletions(-)
diff --git a/drivers/pcmcia/cs.c b/drivers/pcmcia/cs.c
index cc0ba8a..13277ee 100644
--- a/drivers/pcmcia/cs.c
+++ b/drivers/pcmcia/cs.c
@@ -175,8 +175,6 @@ int pcmcia_register_socket(struct pcmcia_socket *socket)
dev_dbg(&socket->dev, "pcmcia_register_socket(0x%p)\n", socket->ops);
- spin_lock_init(&socket->lock);
-
/* try to obtain a socket number [yes, it gets ugly if we
* register more than 2^sizeof(unsigned int) pcmcia
* sockets... but the socket number is deprecated
diff --git a/drivers/pcmcia/cs_internal.h b/drivers/pcmcia/cs_internal.h
index 76ac444..bd386d7 100644
--- a/drivers/pcmcia/cs_internal.h
+++ b/drivers/pcmcia/cs_internal.h
@@ -182,8 +182,6 @@ int pccard_get_tuple_data(struct pcmcia_socket *s, tuple_t *tuple);
#ifdef CONFIG_PCMCIA_IOCTL
/* ds.c */
-extern spinlock_t pcmcia_dev_list_lock;
-
extern struct pcmcia_device *pcmcia_get_dev(struct pcmcia_device *p_dev);
extern void pcmcia_put_dev(struct pcmcia_device *p_dev);
diff --git a/drivers/pcmcia/ds.c b/drivers/pcmcia/ds.c
index 0eb242c..4c40db8 100644
--- a/drivers/pcmcia/ds.c
+++ b/drivers/pcmcia/ds.c
@@ -42,8 +42,6 @@ MODULE_DESCRIPTION("PCMCIA Driver Services");
MODULE_LICENSE("GPL");
-spinlock_t pcmcia_dev_list_lock;
-
/*====================================================================*/
static void pcmcia_check_driver(struct pcmcia_driver *p_drv)
@@ -265,7 +263,6 @@ static int pcmcia_device_probe(struct device *dev)
struct pcmcia_device_id *did;
struct pcmcia_socket *s;
cistpl_config_t cis_config;
- unsigned long flags;
int ret = 0;
dev = get_device(dev);
@@ -316,11 +313,11 @@ static int pcmcia_device_probe(struct device *dev)
goto put_module;
}
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
if (did && (did->match_flags & PCMCIA_DEV_ID_MATCH_DEVICE_NO) &&
(p_dev->socket->device_count == 1) && (p_dev->device_no == 0))
pcmcia_add_device_later(p_dev->socket, 0);
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
put_module:
if (ret)
@@ -339,28 +336,27 @@ static void pcmcia_card_remove(struct pcmcia_socket *s, struct pcmcia_device *le
{
struct pcmcia_device *p_dev;
struct pcmcia_device *tmp;
- unsigned long flags;
dev_dbg(leftover ? &leftover->dev : &s->dev,
"pcmcia_card_remove(%d) %s\n", s->sock,
leftover ? leftover->devname : "");
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
if (!leftover)
s->device_count = 0;
else
s->device_count = 1;
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
/* unregister all pcmcia_devices registered with this socket, except leftover */
list_for_each_entry_safe(p_dev, tmp, &s->devices_list, socket_device_list) {
if (p_dev == leftover)
continue;
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
list_del(&p_dev->socket_device_list);
p_dev->_removed = 1;
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
dev_dbg(&p_dev->dev, "unregistering device\n");
device_unregister(&p_dev->dev);
@@ -507,7 +503,6 @@ static DEFINE_MUTEX(device_add_lock);
struct pcmcia_device *pcmcia_device_add(struct pcmcia_socket *s, unsigned int function)
{
struct pcmcia_device *p_dev, *tmp_dev;
- unsigned long flags;
s = pcmcia_get_socket(s);
if (!s)
@@ -521,9 +516,9 @@ struct pcmcia_device *pcmcia_device_add(struct pcmcia_socket *s, unsigned int fu
if (!p_dev)
goto err_put;
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
p_dev->device_no = (s->device_count++);
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
/* max of 4 devices per card */
if (p_dev->device_no >= 4)
@@ -546,7 +541,7 @@ struct pcmcia_device *pcmcia_device_add(struct pcmcia_socket *s, unsigned int fu
goto err_free;
dev_dbg(&p_dev->dev, "devname is %s\n", p_dev->devname);
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
/*
* p_dev->function_config must be the same for all card functions.
@@ -564,7 +559,7 @@ struct pcmcia_device *pcmcia_device_add(struct pcmcia_socket *s, unsigned int fu
/* Add to the list in pcmcia_bus_socket */
list_add(&p_dev->socket_device_list, &s->devices_list);
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
if (!p_dev->function_config) {
dev_dbg(&p_dev->dev, "creating config_t\n");
@@ -589,14 +584,14 @@ struct pcmcia_device *pcmcia_device_add(struct pcmcia_socket *s, unsigned int fu
return p_dev;
err_unreg:
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
list_del(&p_dev->socket_device_list);
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
err_free:
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
s->device_count--;
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
kfree(p_dev->devname);
kfree(p_dev);
@@ -650,13 +645,12 @@ static void pcmcia_delayed_add_device(struct work_struct *work)
struct pcmcia_socket *s =
container_of(work, struct pcmcia_socket, device_add);
u8 mfc_pfc;
- unsigned long flags;
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
mfc_pfc = s->pcmcia_state.mfc_pfc;
s->pcmcia_state.device_add_pending = 0;
s->pcmcia_state.mfc_pfc = 0;
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
dev_dbg(&s->dev, "adding additional device to %d\n", s->sock);
pcmcia_device_add(s, mfc_pfc);
@@ -677,15 +671,14 @@ static void pcmcia_bus_rescan(struct pcmcia_socket *skt, int new_cis)
{
int no_devices = 0;
int ret = 0;
- unsigned long flags;
/* must be called with skt_mutex held */
dev_dbg(&skt->dev, "re-scanning socket %d\n", skt->sock);
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&skt->ops_mutex);
if (list_empty(&skt->devices_list))
no_devices = 1;
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&skt->ops_mutex);
/* If this is because of a CIS override, start over */
if (new_cis && !no_devices)
@@ -769,11 +762,9 @@ static int pcmcia_load_firmware(struct pcmcia_device *dev, char * filename)
if (old_funcs > no_funcs)
pcmcia_card_remove(s, dev);
else if (no_funcs > old_funcs) {
- unsigned long flags;
-
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
pcmcia_add_device_later(s, 1);
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
}
}
release:
@@ -1248,7 +1239,6 @@ static int pcmcia_bus_suspend(struct pcmcia_socket *skt)
static int ds_event(struct pcmcia_socket *skt, event_t event, int priority)
{
struct pcmcia_socket *s = pcmcia_get_socket(skt);
- unsigned long flags;
if (!s) {
dev_printk(KERN_ERR, &skt->dev,
@@ -1262,9 +1252,9 @@ static int ds_event(struct pcmcia_socket *skt, event_t event, int priority)
switch (event) {
case CS_EVENT_CARD_REMOVAL:
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
s->pcmcia_state.present = 0;
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
pcmcia_card_remove(skt, NULL);
handle_event(skt, event);
mutex_lock(&s->ops_mutex);
@@ -1273,10 +1263,8 @@ static int ds_event(struct pcmcia_socket *skt, event_t event, int priority)
break;
case CS_EVENT_CARD_INSERTION:
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
- s->pcmcia_state.present = 1;
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
mutex_lock(&s->ops_mutex);
+ s->pcmcia_state.present = 1;
destroy_cis_cache(s); /* to be on the safe side... */
mutex_unlock(&s->ops_mutex);
pcmcia_card_add(skt);
@@ -1321,13 +1309,12 @@ struct pcmcia_device *pcmcia_dev_present(struct pcmcia_device *_p_dev)
{
struct pcmcia_device *p_dev;
struct pcmcia_device *ret = NULL;
- unsigned long flags;
p_dev = pcmcia_get_dev(_p_dev);
if (!p_dev)
return NULL;
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&p_dev->socket->ops_mutex);
if (!p_dev->socket->pcmcia_state.present)
goto out;
@@ -1342,7 +1329,7 @@ struct pcmcia_device *pcmcia_dev_present(struct pcmcia_device *_p_dev)
ret = p_dev;
out:
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&p_dev->socket->ops_mutex);
pcmcia_put_dev(p_dev);
return ret;
}
@@ -1406,14 +1393,13 @@ static void pcmcia_bus_remove_socket(struct device *dev,
struct class_interface *class_intf)
{
struct pcmcia_socket *socket = dev_get_drvdata(dev);
- unsigned long flags;
if (!socket)
return;
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&socket->ops_mutex);
socket->pcmcia_state.dead = 1;
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&socket->ops_mutex);
pccard_register_pcmcia(socket, NULL);
@@ -1455,8 +1441,6 @@ static int __init init_pcmcia_bus(void)
{
int ret;
- spin_lock_init(&pcmcia_dev_list_lock);
-
ret = bus_register(&pcmcia_bus_type);
if (ret < 0) {
printk(KERN_WARNING "pcmcia: bus_register error: %d\n", ret);
diff --git a/drivers/pcmcia/pcmcia_ioctl.c b/drivers/pcmcia/pcmcia_ioctl.c
index f73fd5b..db2e3db 100644
--- a/drivers/pcmcia/pcmcia_ioctl.c
+++ b/drivers/pcmcia/pcmcia_ioctl.c
@@ -62,16 +62,15 @@ static struct pcmcia_device *get_pcmcia_device(struct pcmcia_socket *s,
unsigned int function)
{
struct pcmcia_device *p_dev = NULL;
- unsigned long flags;
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
list_for_each_entry(p_dev, &s->devices_list, socket_device_list) {
if (p_dev->func == function) {
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
return pcmcia_get_dev(p_dev);
}
}
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
return NULL;
}
@@ -169,7 +168,6 @@ static int pcmcia_adjust_resource_info(adjust_t *adj)
{
struct pcmcia_socket *s;
int ret = -ENOSYS;
- unsigned long flags;
down_read(&pcmcia_socket_list_rwsem);
list_for_each_entry(s, &pcmcia_socket_list, socket_list) {
@@ -182,14 +180,14 @@ static int pcmcia_adjust_resource_info(adjust_t *adj)
/* you can't use the old interface if the new
* one was used before */
- spin_lock_irqsave(&s->lock, flags);
+ mutex_lock(&s->ops_mutex);
if ((s->resource_setup_new) &&
!(s->resource_setup_old)) {
- spin_unlock_irqrestore(&s->lock, flags);
+ mutex_unlock(&s->ops_mutex);
continue;
} else if (!(s->resource_setup_old))
s->resource_setup_old = 1;
- spin_unlock_irqrestore(&s->lock, flags);
+ mutex_unlock(&s->ops_mutex);
switch (adj->Resource) {
case RES_MEMORY_RANGE:
@@ -208,9 +206,9 @@ static int pcmcia_adjust_resource_info(adjust_t *adj)
* last call to adjust_resource_info, we
* always need to assume this is the latest
* one... */
- spin_lock_irqsave(&s->lock, flags);
+ mutex_lock(&s->ops_mutex);
s->resource_setup_done = 1;
- spin_unlock_irqrestore(&s->lock, flags);
+ mutex_unlock(&s->ops_mutex);
}
}
}
@@ -470,7 +468,6 @@ static int bind_request(struct pcmcia_socket *s, bind_info_t *bind_info)
struct pcmcia_driver *p_drv;
struct pcmcia_device *p_dev;
int ret = 0;
- unsigned long flags;
s = pcmcia_get_socket(s);
if (!s)
@@ -490,7 +487,7 @@ static int bind_request(struct pcmcia_socket *s, bind_info_t *bind_info)
goto err_put_driver;
}
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
list_for_each_entry(p_dev, &s->devices_list, socket_device_list) {
if (p_dev->func == bind_info->function) {
if ((p_dev->dev.driver == &p_drv->drv)) {
@@ -499,7 +496,7 @@ static int bind_request(struct pcmcia_socket *s, bind_info_t *bind_info)
* registered, and it was registered
* by userspace before, we need to
* return the "instance". */
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
bind_info->instance = p_dev;
ret = -EBUSY;
goto err_put_module;
@@ -507,7 +504,7 @@ static int bind_request(struct pcmcia_socket *s, bind_info_t *bind_info)
/* the correct driver managed to bind
* itself magically to the correct
* device. */
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
p_dev->cardmgr = p_drv;
ret = 0;
goto err_put_module;
@@ -516,12 +513,12 @@ static int bind_request(struct pcmcia_socket *s, bind_info_t *bind_info)
/* there's already a device available where
* no device has been bound to yet. So we don't
* need to register a device! */
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
goto rescan;
}
}
}
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
p_dev = pcmcia_device_add(s, bind_info->function);
if (!p_dev) {
@@ -578,7 +575,6 @@ static int get_device_info(struct pcmcia_socket *s, bind_info_t *bind_info, int
dev_node_t *node;
struct pcmcia_device *p_dev;
struct pcmcia_driver *p_drv;
- unsigned long flags;
int ret = 0;
#ifdef CONFIG_CARDBUS
@@ -617,7 +613,7 @@ static int get_device_info(struct pcmcia_socket *s, bind_info_t *bind_info, int
}
#endif
- spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+ mutex_lock(&s->ops_mutex);
list_for_each_entry(p_dev, &s->devices_list, socket_device_list) {
if (p_dev->func == bind_info->function) {
p_dev = pcmcia_get_dev(p_dev);
@@ -626,11 +622,11 @@ static int get_device_info(struct pcmcia_socket *s, bind_info_t *bind_info, int
goto found;
}
}
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
return -ENODEV;
found:
- spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+ mutex_unlock(&s->ops_mutex);
p_drv = to_pcmcia_drv(p_dev->dev.driver);
if (p_drv && !p_dev->_locked) {
diff --git a/drivers/pcmcia/rsrc_mgr.c b/drivers/pcmcia/rsrc_mgr.c
index cdd30c1..b815866 100644
--- a/drivers/pcmcia/rsrc_mgr.c
+++ b/drivers/pcmcia/rsrc_mgr.c
@@ -23,14 +23,12 @@
static int static_init(struct pcmcia_socket *s)
{
- unsigned long flags;
-
/* the good thing about SS_CAP_STATIC_MAP sockets is
* that they don't need a resource database */
- spin_lock_irqsave(&s->lock, flags);
+ mutex_lock(&s->ops_mutex);
s->resource_setup_done = 1;
- spin_unlock_irqrestore(&s->lock, flags);
+ mutex_unlock(&s->ops_mutex);
return 0;
}
diff --git a/drivers/pcmcia/socket_sysfs.c b/drivers/pcmcia/socket_sysfs.c
index 1cba9d3..e8826df 100644
--- a/drivers/pcmcia/socket_sysfs.c
+++ b/drivers/pcmcia/socket_sysfs.c
@@ -189,16 +189,15 @@ static ssize_t pccard_store_resource(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
- unsigned long flags;
struct pcmcia_socket *s = to_socket(dev);
if (!count)
return -EINVAL;
- spin_lock_irqsave(&s->lock, flags);
+ mutex_lock(&s->ops_mutex);
if (!s->resource_setup_done)
s->resource_setup_done = 1;
- spin_unlock_irqrestore(&s->lock, flags);
+ mutex_unlock(&s->ops_mutex);
mutex_lock(&s->skt_mutex);
if ((s->callback) &&
diff --git a/include/pcmcia/ss.h b/include/pcmcia/ss.h
index e756069..cfaccc2 100644
--- a/include/pcmcia/ss.h
+++ b/include/pcmcia/ss.h
@@ -134,7 +134,6 @@ struct pccard_operations {
struct pcmcia_socket {
struct module *owner;
- spinlock_t lock;
socket_state_t socket;
u_int state;
u_int suspended_state; /* state before suspend */
@@ -201,10 +200,12 @@ struct pcmcia_socket {
struct task_struct *thread;
struct completion thread_done;
unsigned int thread_events;
- /* protects socket h/w state */
+
+ /* For the non-trivial interaction between these locks,
+ * see Documentation/pcmcia/locking.txt */
struct mutex skt_mutex;
- /* protects PCMCIA state */
struct mutex ops_mutex;
+
/* protects thread_events */
spinlock_t thread_lock;
--
1.6.3.3
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