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pcmcia: simplify locking
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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 <[email protected]>
Signed-off-by: Dominik Brodowski <[email protected]>
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Dominik Brodowski committed Feb 17, 2010
1 parent 3d3de32 commit 00ce99f
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Showing 7 changed files with 51 additions and 77 deletions.
2 changes: 0 additions & 2 deletions drivers/pcmcia/cs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down
2 changes: 0 additions & 2 deletions drivers/pcmcia/cs_internal.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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);

Expand Down
70 changes: 27 additions & 43 deletions drivers/pcmcia/ds.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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)
Expand All @@ -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);
Expand Down Expand Up @@ -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)
Expand All @@ -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)
Expand All @@ -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.
Expand All @@ -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");
Expand All @@ -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);
Expand Down Expand Up @@ -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);
Expand All @@ -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)
Expand Down Expand Up @@ -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:
Expand Down Expand Up @@ -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,
Expand All @@ -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);
Expand All @@ -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);
Expand Down Expand Up @@ -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;

Expand All @@ -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;
}
Expand Down Expand Up @@ -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);

Expand Down Expand Up @@ -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);
Expand Down
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