[PATCH] pcmcia: "driver services" socket add/remove abstraction

Dominik Brodowski (linux@brodo.de)
Tue, 25 Mar 2003 20:37:03 +0100


Previously, "Driver Services" could only be called when the socket
drivers were initialized earlier. This caused an awful lot of
problems, especially when modprobe tried to load ds.ko and a pcmcia
card driver at once.

As all socket devices are registered with the driver model core as
being of "class_type pcmcia_socket_class", we can take use of that and
register them with "Driver Services" upon detection or upon
module loading of ds.c.

Also, the "I-need-two-initcalls-in-a-module"-tweak can go away.

Unfortunately, this patch reportedly breaks some RedHat pcmcia init
scritps - they relied on the failed loading of ds.c to detect that no
socket driver was loaded previously. To properly detect this, you
should take a look at the /sys/class/pcmcia_socket/devices directory.

ds.c | 363 +++++++++++++++++++++++++++++++++++++++++--------------------------
1 files changed, 223 insertions(+), 140 deletions(-)

diff -ruN linux-original/drivers/pcmcia/ds.c linux/drivers/pcmcia/ds.c
--- linux-original/drivers/pcmcia/ds.c 2003-03-25 18:26:53.000000000 +0100
+++ linux/drivers/pcmcia/ds.c 2003-03-25 19:48:00.000000000 +0100
@@ -48,6 +48,7 @@
#include <linux/proc_fs.h>
#include <linux/poll.h>
#include <linux/pci.h>
+#include <linux/list.h>

#include <pcmcia/version.h>
#include <pcmcia/cs_types.h>
@@ -55,6 +56,7 @@
#include <pcmcia/bulkmem.h>
#include <pcmcia/cistpl.h>
#include <pcmcia/ds.h>
+#include <pcmcia/ss.h>

/*====================================================================*/

@@ -105,6 +107,9 @@
wait_queue_head_t queue, request;
struct timer_list removal;
socket_bind_t *bind;
+ struct device *socket_dev;
+ struct list_head socket_list;
+ unsigned int socket_no; /* deprecated */
} socket_info_t;

#define SOCKET_PRESENT 0x01
@@ -116,8 +121,11 @@
/* Device driver ID passed to Card Services */
static dev_info_t dev_info = "Driver Services";

-static int sockets = 0, major_dev = -1;
-static socket_info_t *socket_table = NULL;
+static int major_dev = -1;
+
+/* list of all sockets registered with the pcmcia bus driver */
+static DECLARE_RWSEM(bus_socket_list_rwsem);
+static LIST_HEAD(bus_socket_list);

extern struct proc_dir_entry *proc_pccard;

@@ -135,6 +143,7 @@
/*======================================================================*/

static struct pcmcia_driver * get_pcmcia_driver (dev_info_t *dev_info);
+static socket_info_t * get_socket_info_by_nr(unsigned int nr);

/**
* pcmcia_register_driver - register a PCMCIA driver with the bus core
@@ -160,17 +169,19 @@
void pcmcia_unregister_driver(struct pcmcia_driver *driver)
{
socket_bind_t *b;
- int i;
+ socket_info_t *bus_sock;

if (driver->use_count > 0) {
/* Blank out any left-over device instances */
driver->attach = NULL; driver->detach = NULL;
- for (i = 0; i < sockets; i++)
- for (b = socket_table[i].bind; b; b = b->next)
+ down_read(&bus_socket_list_rwsem);
+ list_for_each_entry(bus_sock, &bus_socket_list, socket_list) {
+ for (b = bus_sock->bind; b; b = b->next)
if (b->driver == driver)
b->instance = NULL;
- }
-
+ }
+ up_read(&bus_socket_list_rwsem);
+ }
driver_unregister(&driver->drv);
}
EXPORT_SYMBOL(pcmcia_unregister_driver);
@@ -182,7 +193,7 @@
{
struct pcmcia_driver *driver;
socket_bind_t *b;
- int i;
+ socket_info_t *bus_sock;

DEBUG(0, "ds: register_pccard_driver('%s')\n", (char *)dev_info);
driver = get_pcmcia_driver(dev_info);
@@ -199,15 +210,17 @@
if (driver->use_count == 0) return 0;

/* Instantiate any already-bound devices */
- for (i = 0; i < sockets; i++)
- for (b = socket_table[i].bind; b; b = b->next) {
+ down_read(&bus_socket_list_rwsem);
+ list_for_each_entry(bus_sock, &bus_socket_list, socket_list) {
+ for (b = bus_sock->bind; b; b = b->next) {
if (b->driver != driver) continue;
b->instance = driver->attach();
if (b->instance == NULL)
printk(KERN_NOTICE "ds: unable to create instance "
"of '%s'!\n", driver->drv.name);
}
-
+ }
+ up_read(&bus_socket_list_rwsem);
return 0;
} /* register_pccard_driver */

@@ -309,7 +322,7 @@

static void handle_removal(u_long sn)
{
- socket_info_t *s = &socket_table[sn];
+ socket_info_t *s = get_socket_info_by_nr(sn);
handle_event(s, CS_EVENT_CARD_REMOVAL);
s->state &= ~SOCKET_REMOVAL_PENDING;
}
@@ -329,7 +342,7 @@
DEBUG(1, "ds: ds_event(0x%06x, %d, 0x%p)\n",
event, priority, args->client_handle);
s = args->client_data;
- i = s - socket_table;
+ i = s->socket_no;

switch (event) {

@@ -400,9 +413,12 @@
struct pcmcia_driver *driver;
socket_bind_t *b;
bind_req_t bind_req;
- socket_info_t *s = &socket_table[i];
+ socket_info_t *s = get_socket_info_by_nr(i);
int ret;

+ if (!s)
+ return -EINVAL;
+
DEBUG(2, "bind_request(%d, '%s')\n", i,
(char *)bind_info->dev_info);
driver = get_pcmcia_driver(&bind_info->dev_info);
@@ -464,7 +480,7 @@

static int get_device_info(int i, bind_info_t *bind_info, int first)
{
- socket_info_t *s = &socket_table[i];
+ socket_info_t *s = get_socket_info_by_nr(i);
socket_bind_t *b;
dev_node_t *node;

@@ -534,7 +550,7 @@

static int unbind_request(int i, bind_info_t *bind_info)
{
- socket_info_t *s = &socket_table[i];
+ socket_info_t *s = get_socket_info_by_nr(i);
socket_bind_t **b, *c;

DEBUG(2, "unbind_request(%d, '%s')\n", i,
@@ -572,9 +588,11 @@
user_info_t *user;

DEBUG(0, "ds_open(socket %d)\n", i);
- if ((i >= sockets) || (sockets == 0))
- return -ENODEV;
- s = &socket_table[i];
+
+ s = get_socket_info_by_nr(i);
+ if (!s)
+ return -ENODEV;
+
if ((file->f_flags & O_ACCMODE) != O_RDONLY) {
if (s->state & SOCKET_BUSY)
return -EBUSY;
@@ -604,9 +622,11 @@
user_info_t *user, **link;

DEBUG(0, "ds_release(socket %d)\n", i);
- if ((i >= sockets) || (sockets == 0))
- return 0;
- s = &socket_table[i];
+
+ s = get_socket_info_by_nr(i);
+ if (!s)
+ return 0;
+
user = file->private_data;
if (CHECK_USER(user))
goto out;
@@ -637,11 +657,13 @@

DEBUG(2, "ds_read(socket %d)\n", i);

- if ((i >= sockets) || (sockets == 0))
- return -ENODEV;
if (count < 4)
return -EINVAL;
- s = &socket_table[i];
+
+ s = get_socket_info_by_nr(i);
+ if (!s)
+ return -ENODEV;
+
user = file->private_data;
if (CHECK_USER(user))
return -EIO;
@@ -666,13 +688,15 @@

DEBUG(2, "ds_write(socket %d)\n", i);

- if ((i >= sockets) || (sockets == 0))
- return -ENODEV;
if (count != 4)
return -EINVAL;
if ((file->f_flags & O_ACCMODE) == O_RDONLY)
return -EBADF;
- s = &socket_table[i];
+
+ s = get_socket_info_by_nr(i);
+ if (!s)
+ return -ENODEV;
+
user = file->private_data;
if (CHECK_USER(user))
return -EIO;
@@ -699,9 +723,10 @@

DEBUG(2, "ds_poll(socket %d)\n", i);

- if ((i >= sockets) || (sockets == 0))
- return POLLERR;
- s = &socket_table[i];
+ s = get_socket_info_by_nr(i);
+ if (!s)
+ return POLLERR;
+
user = file->private_data;
if (CHECK_USER(user))
return POLLERR;
@@ -724,9 +749,9 @@

DEBUG(2, "ds_ioctl(socket %d, %#x, %#lx)\n", i, cmd, arg);

- if ((i >= sockets) || (sockets == 0))
- return -ENODEV;
- s = &socket_table[i];
+ s = get_socket_info_by_nr(i);
+ if (!s)
+ return -ENODEV;

size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
if (size > sizeof(ds_ioctl_arg_t)) return -EINVAL;
@@ -889,141 +914,199 @@

/*====================================================================*/

-struct bus_type pcmcia_bus_type = {
- .name = "pcmcia",
-};
-EXPORT_SYMBOL(pcmcia_bus_type);
-
-static int __init init_pcmcia_bus(void)
+static int __devinit pcmcia_bus_add_socket(struct device *dev, unsigned int socket_nr)
{
- bus_register(&pcmcia_bus_type);
- return 0;
-}
+ client_reg_t client_reg;
+ bind_req_t bind;
+ socket_info_t *s, *tmp_s;
+ int ret;
+ int i;

-static int __init init_pcmcia_ds(void)
-{
- client_reg_t client_reg;
- servinfo_t serv;
- bind_req_t bind;
- socket_info_t *s;
- int i, ret;
-
- DEBUG(0, "%s\n", version);
-
- /*
- * Ugly. But we want to wait for the socket threads to have started up.
- * We really should let the drivers themselves drive some of this..
- */
- current->state = TASK_INTERRUPTIBLE;
- schedule_timeout(HZ/4);
+ s = kmalloc(sizeof(socket_info_t), GFP_KERNEL);
+ if(!s)
+ return -ENOMEM;
+ memset(s, 0, sizeof(socket_info_t));
+
+ /*
+ * Ugly. But we want to wait for the socket threads to have started up.
+ * We really should let the drivers themselves drive some of this..
+ */
+ current->state = TASK_INTERRUPTIBLE;
+ schedule_timeout(HZ/4);

- pcmcia_get_card_services_info(&serv);
- if (serv.Revision != CS_RELEASE_CODE) {
- printk(KERN_NOTICE "ds: Card Services release does not match!\n");
- return -1;
- }
- if (serv.Count == 0) {
- printk(KERN_NOTICE "ds: no socket drivers loaded!\n");
- return -1;
- }
-
- sockets = serv.Count;
- socket_table = kmalloc(sockets*sizeof(socket_info_t), GFP_KERNEL);
- if (!socket_table) return -1;
- for (i = 0, s = socket_table; i < sockets; i++, s++) {
- s->state = 0;
- s->user = NULL;
- s->req_pending = 0;
init_waitqueue_head(&s->queue);
init_waitqueue_head(&s->request);
- s->handle = NULL;
- init_timer(&s->removal);
- s->removal.data = i;
+
+ /* find the lowest, unused socket no. Please note that this is a
+ * temporary workaround until "struct pcmcia_socket" is introduced
+ * into cs.c which will include this number, and which will be
+ * accessible to ds.c directly */
+ i = 0;
+ next_try:
+ list_for_each_entry(tmp_s, &bus_socket_list, socket_list) {
+ if (tmp_s->socket_no == i) {
+ i++;
+ goto next_try;
+ }
+ }
+ s->socket_no = i;
+
+ /* initialize data */
+ s->socket_dev = dev;
+ s->removal.data = s->socket_no;
s->removal.function = &handle_removal;
- s->bind = NULL;
- }
+ init_timer(&s->removal);

- /* Set up hotline to Card Services */
- client_reg.dev_info = bind.dev_info = &dev_info;
- client_reg.Attributes = INFO_MASTER_CLIENT;
- client_reg.EventMask =
- CS_EVENT_CARD_INSERTION | CS_EVENT_CARD_REMOVAL |
- CS_EVENT_RESET_PHYSICAL | CS_EVENT_CARD_RESET |
- CS_EVENT_EJECTION_REQUEST | CS_EVENT_INSERTION_REQUEST |
- CS_EVENT_PM_SUSPEND | CS_EVENT_PM_RESUME;
- client_reg.event_handler = &ds_event;
- client_reg.Version = 0x0210;
- for (i = 0; i < sockets; i++) {
- bind.Socket = i;
+ /* Set up hotline to Card Services */
+ client_reg.dev_info = bind.dev_info = &dev_info;
+
+ bind.Socket = s->socket_no;
bind.Function = BIND_FN_ALL;
ret = pcmcia_bind_device(&bind);
if (ret != CS_SUCCESS) {
- cs_error(NULL, BindDevice, ret);
- break;
+ cs_error(NULL, BindDevice, ret);
+ kfree(s);
+ return -EINVAL;
}
- client_reg.event_callback_args.client_data = &socket_table[i];
- ret = pcmcia_register_client(&socket_table[i].handle,
- &client_reg);
+
+ client_reg.Attributes = INFO_MASTER_CLIENT;
+ client_reg.EventMask =
+ CS_EVENT_CARD_INSERTION | CS_EVENT_CARD_REMOVAL |
+ CS_EVENT_RESET_PHYSICAL | CS_EVENT_CARD_RESET |
+ CS_EVENT_EJECTION_REQUEST | CS_EVENT_INSERTION_REQUEST |
+ CS_EVENT_PM_SUSPEND | CS_EVENT_PM_RESUME;
+ client_reg.event_handler = &ds_event;
+ client_reg.Version = 0x0210;
+ client_reg.event_callback_args.client_data = s;
+ ret = pcmcia_register_client(&s->handle, &client_reg);
if (ret != CS_SUCCESS) {
- cs_error(NULL, RegisterClient, ret);
- break;
+ cs_error(NULL, RegisterClient, ret);
+ kfree(s);
+ return -EINVAL;
}
- }
-
- /* Set up character device for user mode clients */
- i = register_chrdev(0, "pcmcia", &ds_fops);
- if (i == -EBUSY)
- printk(KERN_NOTICE "unable to find a free device # for "
- "Driver Services\n");
- else
- major_dev = i;

-#ifdef CONFIG_PROC_FS
- if (proc_pccard)
- create_proc_read_entry("drivers",0,proc_pccard,proc_read_drivers,NULL);
- init_status = 0;
-#endif
- return 0;
+ list_add(&s->socket_list, &bus_socket_list);
+
+ return 0;
}


-static void __exit exit_pcmcia_ds(void)
+static int __devinit pcmcia_bus_add_socket_dev(struct device *dev)
{
- int i;
+ struct pcmcia_socket_class_data *cls_d = dev->class_data;
+ unsigned int i;
+ unsigned int ret = 0;
+
+ if (!cls_d)
+ return -ENODEV;
+
+ down_write(&bus_socket_list_rwsem);
+ for (i = 0; i < cls_d->nsock; i++)
+ ret += pcmcia_bus_add_socket(dev, i);
+ up_write(&bus_socket_list_rwsem);
+
+ return ret;
+}
+
+static int __devexit pcmcia_bus_remove_socket_dev(struct device *dev)
+{
+ struct pcmcia_socket_class_data *cls_d = dev->class_data;
+ struct list_head *list_loop;
+ struct list_head *tmp_storage;
+
+ if (!cls_d)
+ return -ENODEV;
+
+ down_write(&bus_socket_list_rwsem);
+ list_for_each_safe(list_loop, tmp_storage, &bus_socket_list) {
+ socket_info_t *bus_sock = container_of(list_loop, socket_info_t, socket_list);
+ if (bus_sock->socket_dev == dev) {
+ pcmcia_deregister_client(bus_sock->handle);
+ list_del(&bus_sock->socket_list);
+ kfree(bus_sock);
+ }
+ }
+ up_write(&bus_socket_list_rwsem);
+ return 0;
+}
+
+
+/* the pcmcia_bus_interface is used to handle pcmcia socket devices */
+static struct device_interface pcmcia_bus_interface = {
+ .name = "pcmcia-bus",
+ .devclass = &pcmcia_socket_class,
+ .add_device = &pcmcia_bus_add_socket_dev,
+ .remove_device = __devexit_p(&pcmcia_bus_remove_socket_dev),
+ .kset = { .subsys = &pcmcia_socket_class.subsys, },
+ .devnum = 0,
+};
+
+
+struct bus_type pcmcia_bus_type = {
+ .name = "pcmcia",
+};
+EXPORT_SYMBOL(pcmcia_bus_type);
+
+
+static int __init init_pcmcia_bus(void)
+{
+ int i;
+
+ bus_register(&pcmcia_bus_type);
+ interface_register(&pcmcia_bus_interface);
+
+ /* Set up character device for user mode clients */
+ i = register_chrdev(0, "pcmcia", &ds_fops);
+ if (i == -EBUSY)
+ printk(KERN_NOTICE "unable to find a free device # for "
+ "Driver Services\n");
+ else
+ major_dev = i;
+
#ifdef CONFIG_PROC_FS
- if (proc_pccard)
- remove_proc_entry("drivers", proc_pccard);
+ if (proc_pccard)
+ create_proc_read_entry("drivers",0,proc_pccard,proc_read_drivers,NULL);
#endif
- if (major_dev != -1)
- unregister_chrdev(major_dev, "pcmcia");
- for (i = 0; i < sockets; i++)
- pcmcia_deregister_client(socket_table[i].handle);
- sockets = 0;
- kfree(socket_table);
- bus_unregister(&pcmcia_bus_type);
+
+ return 0;
}
+fs_initcall(init_pcmcia_bus); /* one level after subsys_initcall so that
+ * pcmcia_socket_class is already registered */

-#ifdef MODULE

-/* init_pcmcia_bus must be done early, init_pcmcia_ds late. If we load this
- * as a module, we can only specify one initcall, though...
- */
-static int __init init_pcmcia_module(void) {
- init_pcmcia_bus();
- return init_pcmcia_ds();
-}
-module_init(init_pcmcia_module);
-
-#else /* !MODULE */
-subsys_initcall(init_pcmcia_bus);
-late_initcall(init_pcmcia_ds);
+static void __exit exit_pcmcia_bus(void)
+{
+ interface_unregister(&pcmcia_bus_interface);
+
+#ifdef CONFIG_PROC_FS
+ if (proc_pccard)
+ remove_proc_entry("drivers", proc_pccard);
#endif
+ if (major_dev != -1)
+ unregister_chrdev(major_dev, "pcmcia");
+
+ bus_unregister(&pcmcia_bus_type);
+}
+module_exit(exit_pcmcia_bus);

-module_exit(exit_pcmcia_ds);


/* helpers for backwards-compatible functions */

+
+static socket_info_t * get_socket_info_by_nr(unsigned int nr)
+{
+ socket_info_t * s;
+ down_read(&bus_socket_list_rwsem);
+ list_for_each_entry(s, &bus_socket_list, socket_list)
+ if (s->socket_no == nr) {
+ up_read(&bus_socket_list_rwsem);
+ return s;
+ }
+ up_read(&bus_socket_list_rwsem);
+ return NULL;
+}
+
/* backwards-compatible accessing of driver --- by name! */

struct cmp_data {
-
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