[PATCH] pcmcia: make config_t independent, add reference counting

Handle config_t structs independent of struct pcmcia_socket, and add
reference counting for them.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

3 files changed, 45 insertions, 29 deletions

diff --git a/drivers/pcmcia/cs.c b/drivers/pcmcia/cs.c
index 613f2f1fbfdd..45cffbf285c2 100644
--- a/drivers/pcmcia/cs.c
+++ b/drivers/pcmcia/cs.c
@@ -406,8 +406,6 @@ static void socket_shutdown(struct pcmcia_socket *s)
         cb_free(s);
 #endif
         s->functions = 0;
-        kfree(s->config);
-        s->config = NULL;
 
         s->ops->get_status(s, &status);
         if (status & SS_POWERON) {
diff --git a/drivers/pcmcia/cs_internal.h b/drivers/pcmcia/cs_internal.h
index 88c96aee0f45..01c32af559bf 100644
--- a/drivers/pcmcia/cs_internal.h
+++ b/drivers/pcmcia/cs_internal.h
@@ -16,6 +16,7 @@
 #define _LINUX_CS_INTERNAL_H
 
 #include <linux/config.h>
+#include <linux/kref.h>
 
 /* Flags in client state */
 #define CLIENT_CONFIG_LOCKED    0x0001
@@ -40,6 +41,7 @@ typedef struct region_t {
 
 /* Each card function gets one of these guys */
 typedef struct config_t {
+        struct kref     ref;
     u_int               state;
     u_int               Attributes;
     u_int               IntType;
diff --git a/drivers/pcmcia/ds.c b/drivers/pcmcia/ds.c
index 5166f00cfe3a..37ba1246c282 100644
--- a/drivers/pcmcia/ds.c
+++ b/drivers/pcmcia/ds.c
@@ -23,6 +23,7 @@
 #include <linux/workqueue.h>
 #include <linux/crc32.h>
 #include <linux/firmware.h>
+#include <linux/kref.h>
 
 #define IN_CARD_SERVICES
 #include <pcmcia/cs_types.h>
@@ -343,12 +344,19 @@ void pcmcia_put_dev(struct pcmcia_device *p_dev)
                 put_device(&p_dev->dev);
 }
 
+static void pcmcia_release_function(struct kref *ref)
+{
+        struct config_t *c = container_of(ref, struct config_t, ref);
+        kfree(c);
+}
+
 static void pcmcia_release_dev(struct device *dev)
 {
         struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
         ds_dbg(1, "releasing dev %p\n", p_dev);
         pcmcia_put_socket(p_dev->socket);
         kfree(p_dev->devname);
+        kref_put(&p_dev->function_config->ref, pcmcia_release_function);
         kfree(p_dev);
 }
 
@@ -377,30 +385,14 @@ static int pcmcia_device_probe(struct device * dev)
         p_drv = to_pcmcia_drv(dev->driver);
         s = p_dev->socket;
 
-        if ((!p_drv->probe) || (!try_module_get(p_drv->owner))) {
+        if ((!p_drv->probe) || (!p_dev->function_config) ||
+            (!try_module_get(p_drv->owner))) {
                 ret = -EINVAL;
                 goto put_dev;
         }
 
         p_dev->state &= ~CLIENT_UNBOUND;
 
-        /* set up the device configuration, if it hasn't been done before */
-        if (!s->functions) {
-                cistpl_longlink_mfc_t mfc;
-                if (pccard_read_tuple(s, p_dev->func, CISTPL_LONGLINK_MFC,
-                                      &mfc) == CS_SUCCESS)
-                        s->functions = mfc.nfn;
-                else
-                        s->functions = 1;
-                s->config = kzalloc(sizeof(config_t) * s->functions,
-                                    GFP_KERNEL);
-                if (!s->config) {
-                        ret = -ENOMEM;
-                        goto put_module;
-                }
-        }
-        p_dev->function_config = &s->config[p_dev->func];
-
         ret = p_drv->probe(p_dev);
         if (ret)
                 goto put_module;
@@ -576,7 +568,7 @@ static DECLARE_MUTEX(device_add_lock);
 
 struct pcmcia_device * pcmcia_device_add(struct pcmcia_socket *s, unsigned int function)
 {
-        struct pcmcia_device *p_dev;
+        struct pcmcia_device *p_dev, *tmp_dev;
         unsigned long flags;
         int bus_id_len;
 
@@ -597,6 +589,8 @@ struct pcmcia_device * pcmcia_device_add(struct pcmcia_socket *s, unsigned int f
         p_dev->socket = s;
         p_dev->device_no = (s->device_count++);
         p_dev->func   = function;
+        if (s->functions < function)
+                s->functions = function;
 
         p_dev->dev.bus = &pcmcia_bus_type;
         p_dev->dev.parent = s->dev.dev;
@@ -611,28 +605,50 @@ struct pcmcia_device * pcmcia_device_add(struct pcmcia_socket *s, unsigned int f
         /* compat */
         p_dev->state = CLIENT_UNBOUND;
 
-        /* Add to the list in pcmcia_bus_socket */
+
         spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+
+        /*
+         * p_dev->function_config must be the same for all card functions.
+         * Note that this is serialized by the device_add_lock, so that
+         * only one such struct will be created.
+         */
+        list_for_each_entry(tmp_dev, &s->devices_list, socket_device_list)
+                if (p_dev->func == tmp_dev->func) {
+                        p_dev->function_config = tmp_dev->function_config;
+                        kref_get(&p_dev->function_config->ref);
+                }
+
+        /* Add to the list in pcmcia_bus_socket */
         list_add_tail(&p_dev->socket_device_list, &s->devices_list);
+
         spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
 
+        if (!p_dev->function_config) {
+                p_dev->function_config = kzalloc(sizeof(struct config_t),
+                                                 GFP_KERNEL);
+                if (!p_dev->function_config)
+                        goto err_unreg;
+                kref_init(&p_dev->function_config->ref);
+        }
+
         printk(KERN_NOTICE "pcmcia: registering new device %s\n",
                p_dev->devname);
 
         pcmcia_device_query(p_dev);
 
-        if (device_register(&p_dev->dev)) {
-                spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
-                list_del(&p_dev->socket_device_list);
-                spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
-
-                goto err_free;
-       }
+        if (device_register(&p_dev->dev))
+                goto err_unreg;
 
         up(&device_add_lock);
 
         return p_dev;
 
+ err_unreg:
+        spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+        list_del(&p_dev->socket_device_list);
+        spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+
  err_free:
         kfree(p_dev->devname);
         kfree(p_dev);