linux/drivers/pcmcia/ds.c
Russell King 025e4ab3db pcmcia: fix socket refcount decrementing on each resume
This fixes a memory-corrupting bug: not only does it cause the warning,
but as a result of dropping the refcount to zero, it causes the
pcmcia_socket0 device structure to be freed while it still has
references, causing slab caches corruption.  A fatal oops quickly
follows this warning - often even just a 'dmesg' following the warning
causes the kernel to oops.

While testing suspend/resume on an ARM device with PCMCIA support, and a
CF card inserted, I found that after five suspend and resumes, the
kernel would complain, and shortly die after with slab corruption.

  WARNING: at include/linux/kref.h:41 kobject_get+0x28/0x50()

As the message doesn't give a clue about which kobject, and the built-in
debugging in drivers/base/power/main.c happens too late, this was added
right before each get_device():

  printk("%s: %p [%s] %u\n", __func__, dev, kobject_name(&dev->kobj), atomic_read(&dev->kobj.kref.refcount));

and on the 3rd s2ram cycle, the following behaviour observed:

On the 3rd suspend/resume cycle:

  dpm_prepare: c1a0d998 [pcmcia_socket0] 3
  dpm_suspend: c1a0d998 [pcmcia_socket0] 3
  dpm_suspend_noirq: c1a0d998 [pcmcia_socket0] 3
  dpm_resume_noirq: c1a0d998 [pcmcia_socket0] 3
  dpm_resume: c1a0d998 [pcmcia_socket0] 3
  dpm_complete: c1a0d998 [pcmcia_socket0] 2

4th:

  dpm_prepare: c1a0d998 [pcmcia_socket0] 2
  dpm_suspend: c1a0d998 [pcmcia_socket0] 2
  dpm_suspend_noirq: c1a0d998 [pcmcia_socket0] 2
  dpm_resume_noirq: c1a0d998 [pcmcia_socket0] 2
  dpm_resume: c1a0d998 [pcmcia_socket0] 2
  dpm_complete: c1a0d998 [pcmcia_socket0] 1

5th:

  dpm_prepare: c1a0d998 [pcmcia_socket0] 1
  dpm_suspend: c1a0d998 [pcmcia_socket0] 1
  dpm_suspend_noirq: c1a0d998 [pcmcia_socket0] 1
  dpm_resume_noirq: c1a0d998 [pcmcia_socket0] 1
  dpm_resume: c1a0d998 [pcmcia_socket0] 1
  dpm_complete: c1a0d998 [pcmcia_socket0] 0
  ------------[ cut here ]------------
  WARNING: at include/linux/kref.h:41 kobject_get+0x28/0x50()
  Modules linked in: ucb1x00_core
  Backtrace:
  [<c0212090>] (dump_backtrace+0x0/0x110) from [<c04799dc>] (dump_stack+0x18/0x1c)
  [<c04799c4>] (dump_stack+0x0/0x1c) from [<c021cba0>] (warn_slowpath_common+0x50/0x68)
  [<c021cb50>] (warn_slowpath_common+0x0/0x68) from [<c021cbdc>] (warn_slowpath_null+0x24/0x28)
  [<c021cbb8>] (warn_slowpath_null+0x0/0x28) from [<c0335374>] (kobject_get+0x28/0x50)
  [<c033534c>] (kobject_get+0x0/0x50) from [<c03804f4>] (get_device+0x1c/0x24)
  [<c0388c90>] (dpm_complete+0x0/0x1a0) from [<c0389cc0>] (dpm_resume_end+0x1c/0x20)
  ...

Looking at commit 7b24e79882 ("pcmcia: split up central event handler"),
the following change was made to cs.c:

                return 0;
        }
 #endif
-
-       send_event(skt, CS_EVENT_PM_RESUME, CS_EVENT_PRI_LOW);
+       if (!(skt->state & SOCKET_CARDBUS) && (skt->callback))
+               skt->callback->early_resume(skt);
        return 0;
 }

And the corresponding change in ds.c is from:

-static int ds_event(struct pcmcia_socket *skt, event_t event, int priority)
-{
-       struct pcmcia_socket *s = pcmcia_get_socket(skt);
...
-       switch (event) {
...
-       case CS_EVENT_PM_RESUME:
-               if (verify_cis_cache(skt) != 0) {
-                       dev_dbg(&skt->dev, "cis mismatch - different card\n");
-                       /* first, remove the card */
-                       ds_event(skt, CS_EVENT_CARD_REMOVAL, CS_EVENT_PRI_HIGH);
-                       mutex_lock(&s->ops_mutex);
-                       destroy_cis_cache(skt);
-                       kfree(skt->fake_cis);
-                       skt->fake_cis = NULL;
-                       s->functions = 0;
-                       mutex_unlock(&s->ops_mutex);
-                       /* now, add the new card */
-                       ds_event(skt, CS_EVENT_CARD_INSERTION,
-                                CS_EVENT_PRI_LOW);
-               }
-               break;
...
-    }

-    pcmcia_put_socket(s);

-    return 0;
-} /* ds_event */

to:

+static int pcmcia_bus_early_resume(struct pcmcia_socket *skt)
+{
+       if (!verify_cis_cache(skt)) {
+               pcmcia_put_socket(skt);
+               return 0;
+       }

+       dev_dbg(&skt->dev, "cis mismatch - different card\n");

+       /* first, remove the card */
+       pcmcia_bus_remove(skt);
+       mutex_lock(&skt->ops_mutex);
+       destroy_cis_cache(skt);
+       kfree(skt->fake_cis);
+       skt->fake_cis = NULL;
+       skt->functions = 0;
+       mutex_unlock(&skt->ops_mutex);

+       /* now, add the new card */
+       pcmcia_bus_add(skt);
+       return 0;
+}

As can be seen, the original function called pcmcia_get_socket() and
pcmcia_put_socket() around the guts, whereas the replacement code
calls pcmcia_put_socket() only in one path.  This creates an imbalance
in the refcounting.

Testing with pcmcia_put_socket() put removed shows that the bug is gone:

  dpm_suspend: c1a10998 [pcmcia_socket0] 5
  dpm_suspend_noirq: c1a10998 [pcmcia_socket0] 5
  dpm_resume_noirq: c1a10998 [pcmcia_socket0] 5
  dpm_resume: c1a10998 [pcmcia_socket0] 5
  dpm_complete: c1a10998 [pcmcia_socket0] 5

Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-08 19:03:51 -08:00

1441 lines
34 KiB
C

/*
* ds.c -- 16-bit PCMCIA core support
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* The initial developer of the original code is David A. Hinds
* <dahinds@users.sourceforge.net>. Portions created by David A. Hinds
* are Copyright (C) 1999 David A. Hinds. All Rights Reserved.
*
* (C) 1999 David A. Hinds
* (C) 2003 - 2010 Dominik Brodowski
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/crc32.h>
#include <linux/firmware.h>
#include <linux/kref.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <pcmcia/cistpl.h>
#include <pcmcia/ds.h>
#include <pcmcia/ss.h>
#include "cs_internal.h"
/*====================================================================*/
/* Module parameters */
MODULE_AUTHOR("David Hinds <dahinds@users.sourceforge.net>");
MODULE_DESCRIPTION("PCMCIA Driver Services");
MODULE_LICENSE("GPL");
/*====================================================================*/
static void pcmcia_check_driver(struct pcmcia_driver *p_drv)
{
const struct pcmcia_device_id *did = p_drv->id_table;
unsigned int i;
u32 hash;
if (!p_drv->probe || !p_drv->remove)
printk(KERN_DEBUG "pcmcia: %s lacks a requisite callback "
"function\n", p_drv->name);
while (did && did->match_flags) {
for (i = 0; i < 4; i++) {
if (!did->prod_id[i])
continue;
hash = crc32(0, did->prod_id[i], strlen(did->prod_id[i]));
if (hash == did->prod_id_hash[i])
continue;
printk(KERN_DEBUG "pcmcia: %s: invalid hash for "
"product string \"%s\": is 0x%x, should "
"be 0x%x\n", p_drv->name, did->prod_id[i],
did->prod_id_hash[i], hash);
printk(KERN_DEBUG "pcmcia: see "
"Documentation/pcmcia/devicetable.txt for "
"details\n");
}
did++;
}
return;
}
/*======================================================================*/
struct pcmcia_dynid {
struct list_head node;
struct pcmcia_device_id id;
};
/**
* pcmcia_store_new_id - add a new PCMCIA device ID to this driver and re-probe devices
* @driver: target device driver
* @buf: buffer for scanning device ID data
* @count: input size
*
* Adds a new dynamic PCMCIA device ID to this driver,
* and causes the driver to probe for all devices again.
*/
static ssize_t
pcmcia_store_new_id(struct device_driver *driver, const char *buf, size_t count)
{
struct pcmcia_dynid *dynid;
struct pcmcia_driver *pdrv = to_pcmcia_drv(driver);
__u16 match_flags, manf_id, card_id;
__u8 func_id, function, device_no;
__u32 prod_id_hash[4] = {0, 0, 0, 0};
int fields = 0;
int retval = 0;
fields = sscanf(buf, "%hx %hx %hx %hhx %hhx %hhx %x %x %x %x",
&match_flags, &manf_id, &card_id, &func_id, &function, &device_no,
&prod_id_hash[0], &prod_id_hash[1], &prod_id_hash[2], &prod_id_hash[3]);
if (fields < 6)
return -EINVAL;
dynid = kzalloc(sizeof(struct pcmcia_dynid), GFP_KERNEL);
if (!dynid)
return -ENOMEM;
dynid->id.match_flags = match_flags;
dynid->id.manf_id = manf_id;
dynid->id.card_id = card_id;
dynid->id.func_id = func_id;
dynid->id.function = function;
dynid->id.device_no = device_no;
memcpy(dynid->id.prod_id_hash, prod_id_hash, sizeof(__u32) * 4);
mutex_lock(&pdrv->dynids.lock);
list_add_tail(&dynid->node, &pdrv->dynids.list);
mutex_unlock(&pdrv->dynids.lock);
if (get_driver(&pdrv->drv)) {
retval = driver_attach(&pdrv->drv);
put_driver(&pdrv->drv);
}
if (retval)
return retval;
return count;
}
static DRIVER_ATTR(new_id, S_IWUSR, NULL, pcmcia_store_new_id);
static void
pcmcia_free_dynids(struct pcmcia_driver *drv)
{
struct pcmcia_dynid *dynid, *n;
mutex_lock(&drv->dynids.lock);
list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
list_del(&dynid->node);
kfree(dynid);
}
mutex_unlock(&drv->dynids.lock);
}
static int
pcmcia_create_newid_file(struct pcmcia_driver *drv)
{
int error = 0;
if (drv->probe != NULL)
error = driver_create_file(&drv->drv, &driver_attr_new_id);
return error;
}
/**
* pcmcia_register_driver - register a PCMCIA driver with the bus core
* @driver: the &driver being registered
*
* Registers a PCMCIA driver with the PCMCIA bus core.
*/
int pcmcia_register_driver(struct pcmcia_driver *driver)
{
int error;
if (!driver)
return -EINVAL;
pcmcia_check_driver(driver);
/* initialize common fields */
driver->drv.bus = &pcmcia_bus_type;
driver->drv.owner = driver->owner;
driver->drv.name = driver->name;
mutex_init(&driver->dynids.lock);
INIT_LIST_HEAD(&driver->dynids.list);
pr_debug("registering driver %s\n", driver->name);
error = driver_register(&driver->drv);
if (error < 0)
return error;
error = pcmcia_create_newid_file(driver);
if (error)
driver_unregister(&driver->drv);
return error;
}
EXPORT_SYMBOL(pcmcia_register_driver);
/**
* pcmcia_unregister_driver - unregister a PCMCIA driver with the bus core
* @driver: the &driver being unregistered
*/
void pcmcia_unregister_driver(struct pcmcia_driver *driver)
{
pr_debug("unregistering driver %s\n", driver->name);
driver_unregister(&driver->drv);
pcmcia_free_dynids(driver);
}
EXPORT_SYMBOL(pcmcia_unregister_driver);
/* pcmcia_device handling */
static struct pcmcia_device *pcmcia_get_dev(struct pcmcia_device *p_dev)
{
struct device *tmp_dev;
tmp_dev = get_device(&p_dev->dev);
if (!tmp_dev)
return NULL;
return to_pcmcia_dev(tmp_dev);
}
static void pcmcia_put_dev(struct pcmcia_device *p_dev)
{
if (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);
pr_debug("releasing config_t\n");
kfree(c);
}
static void pcmcia_release_dev(struct device *dev)
{
struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
int i;
dev_dbg(dev, "releasing device\n");
pcmcia_put_socket(p_dev->socket);
for (i = 0; i < 4; i++)
kfree(p_dev->prod_id[i]);
kfree(p_dev->devname);
kref_put(&p_dev->function_config->ref, pcmcia_release_function);
kfree(p_dev);
}
static int pcmcia_device_probe(struct device *dev)
{
struct pcmcia_device *p_dev;
struct pcmcia_driver *p_drv;
struct pcmcia_socket *s;
cistpl_config_t cis_config;
int ret = 0;
dev = get_device(dev);
if (!dev)
return -ENODEV;
p_dev = to_pcmcia_dev(dev);
p_drv = to_pcmcia_drv(dev->driver);
s = p_dev->socket;
dev_dbg(dev, "trying to bind to %s\n", p_drv->name);
if ((!p_drv->probe) || (!p_dev->function_config) ||
(!try_module_get(p_drv->owner))) {
ret = -EINVAL;
goto put_dev;
}
/* set up some more device information */
ret = pccard_read_tuple(p_dev->socket, p_dev->func, CISTPL_CONFIG,
&cis_config);
if (!ret) {
p_dev->config_base = cis_config.base;
p_dev->config_regs = cis_config.rmask[0];
dev_dbg(dev, "base %x, regs %x", p_dev->config_base,
p_dev->config_regs);
} else {
dev_printk(KERN_INFO, dev,
"pcmcia: could not parse base and rmask0 of CIS\n");
p_dev->config_base = 0;
p_dev->config_regs = 0;
}
ret = p_drv->probe(p_dev);
if (ret) {
dev_dbg(dev, "binding to %s failed with %d\n",
p_drv->name, ret);
goto put_module;
}
dev_dbg(dev, "%s bound: Vpp %d.%d, idx %x, IRQ %d", p_drv->name,
p_dev->vpp/10, p_dev->vpp%10, p_dev->config_index, p_dev->irq);
dev_dbg(dev, "resources: ioport %pR %pR iomem %pR %pR %pR",
p_dev->resource[0], p_dev->resource[1], p_dev->resource[2],
p_dev->resource[3], p_dev->resource[4]);
mutex_lock(&s->ops_mutex);
if ((s->pcmcia_pfc) &&
(p_dev->socket->device_count == 1) && (p_dev->device_no == 0))
pcmcia_parse_uevents(s, PCMCIA_UEVENT_REQUERY);
mutex_unlock(&s->ops_mutex);
put_module:
if (ret)
module_put(p_drv->owner);
put_dev:
if (ret)
put_device(dev);
return ret;
}
/*
* Removes a PCMCIA card from the device tree and socket list.
*/
static void pcmcia_card_remove(struct pcmcia_socket *s, struct pcmcia_device *leftover)
{
struct pcmcia_device *p_dev;
struct pcmcia_device *tmp;
dev_dbg(leftover ? &leftover->dev : &s->dev,
"pcmcia_card_remove(%d) %s\n", s->sock,
leftover ? leftover->devname : "");
mutex_lock(&s->ops_mutex);
if (!leftover)
s->device_count = 0;
else
s->device_count = 1;
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;
mutex_lock(&s->ops_mutex);
list_del(&p_dev->socket_device_list);
mutex_unlock(&s->ops_mutex);
dev_dbg(&p_dev->dev, "unregistering device\n");
device_unregister(&p_dev->dev);
}
return;
}
static int pcmcia_device_remove(struct device *dev)
{
struct pcmcia_device *p_dev;
struct pcmcia_driver *p_drv;
int i;
p_dev = to_pcmcia_dev(dev);
p_drv = to_pcmcia_drv(dev->driver);
dev_dbg(dev, "removing device\n");
/* If we're removing the primary module driving a
* pseudo multi-function card, we need to unbind
* all devices
*/
if ((p_dev->socket->pcmcia_pfc) &&
(p_dev->socket->device_count > 0) &&
(p_dev->device_no == 0))
pcmcia_card_remove(p_dev->socket, p_dev);
/* detach the "instance" */
if (!p_drv)
return 0;
if (p_drv->remove)
p_drv->remove(p_dev);
/* check for proper unloading */
if (p_dev->_irq || p_dev->_io || p_dev->_locked)
dev_printk(KERN_INFO, dev,
"pcmcia: driver %s did not release config properly\n",
p_drv->name);
for (i = 0; i < MAX_WIN; i++)
if (p_dev->_win & CLIENT_WIN_REQ(i))
dev_printk(KERN_INFO, dev,
"pcmcia: driver %s did not release window properly\n",
p_drv->name);
/* references from pcmcia_probe_device */
pcmcia_put_dev(p_dev);
module_put(p_drv->owner);
return 0;
}
/*
* pcmcia_device_query -- determine information about a pcmcia device
*/
static int pcmcia_device_query(struct pcmcia_device *p_dev)
{
cistpl_manfid_t manf_id;
cistpl_funcid_t func_id;
cistpl_vers_1_t *vers1;
unsigned int i;
vers1 = kmalloc(sizeof(*vers1), GFP_KERNEL);
if (!vers1)
return -ENOMEM;
if (!pccard_read_tuple(p_dev->socket, BIND_FN_ALL,
CISTPL_MANFID, &manf_id)) {
mutex_lock(&p_dev->socket->ops_mutex);
p_dev->manf_id = manf_id.manf;
p_dev->card_id = manf_id.card;
p_dev->has_manf_id = 1;
p_dev->has_card_id = 1;
mutex_unlock(&p_dev->socket->ops_mutex);
}
if (!pccard_read_tuple(p_dev->socket, p_dev->func,
CISTPL_FUNCID, &func_id)) {
mutex_lock(&p_dev->socket->ops_mutex);
p_dev->func_id = func_id.func;
p_dev->has_func_id = 1;
mutex_unlock(&p_dev->socket->ops_mutex);
} else {
/* rule of thumb: cards with no FUNCID, but with
* common memory device geometry information, are
* probably memory cards (from pcmcia-cs) */
cistpl_device_geo_t *devgeo;
devgeo = kmalloc(sizeof(*devgeo), GFP_KERNEL);
if (!devgeo) {
kfree(vers1);
return -ENOMEM;
}
if (!pccard_read_tuple(p_dev->socket, p_dev->func,
CISTPL_DEVICE_GEO, devgeo)) {
dev_dbg(&p_dev->dev,
"mem device geometry probably means "
"FUNCID_MEMORY\n");
mutex_lock(&p_dev->socket->ops_mutex);
p_dev->func_id = CISTPL_FUNCID_MEMORY;
p_dev->has_func_id = 1;
mutex_unlock(&p_dev->socket->ops_mutex);
}
kfree(devgeo);
}
if (!pccard_read_tuple(p_dev->socket, BIND_FN_ALL, CISTPL_VERS_1,
vers1)) {
mutex_lock(&p_dev->socket->ops_mutex);
for (i = 0; i < min_t(unsigned int, 4, vers1->ns); i++) {
char *tmp;
unsigned int length;
char *new;
tmp = vers1->str + vers1->ofs[i];
length = strlen(tmp) + 1;
if ((length < 2) || (length > 255))
continue;
new = kmalloc(sizeof(char) * length, GFP_KERNEL);
if (!new)
continue;
new = strncpy(new, tmp, length);
tmp = p_dev->prod_id[i];
p_dev->prod_id[i] = new;
kfree(tmp);
}
mutex_unlock(&p_dev->socket->ops_mutex);
}
kfree(vers1);
return 0;
}
static struct pcmcia_device *pcmcia_device_add(struct pcmcia_socket *s,
unsigned int function)
{
struct pcmcia_device *p_dev, *tmp_dev;
int i;
s = pcmcia_get_socket(s);
if (!s)
return NULL;
pr_debug("adding device to %d, function %d\n", s->sock, function);
p_dev = kzalloc(sizeof(struct pcmcia_device), GFP_KERNEL);
if (!p_dev)
goto err_put;
mutex_lock(&s->ops_mutex);
p_dev->device_no = (s->device_count++);
mutex_unlock(&s->ops_mutex);
/* max of 2 PFC devices */
if ((p_dev->device_no >= 2) && (function == 0))
goto err_free;
/* max of 4 devices overall */
if (p_dev->device_no >= 4)
goto err_free;
p_dev->socket = s;
p_dev->func = function;
p_dev->dev.bus = &pcmcia_bus_type;
p_dev->dev.parent = s->dev.parent;
p_dev->dev.release = pcmcia_release_dev;
/* by default don't allow DMA */
p_dev->dma_mask = DMA_MASK_NONE;
p_dev->dev.dma_mask = &p_dev->dma_mask;
dev_set_name(&p_dev->dev, "%d.%d", p_dev->socket->sock, p_dev->device_no);
if (!dev_name(&p_dev->dev))
goto err_free;
p_dev->devname = kasprintf(GFP_KERNEL, "pcmcia%s", dev_name(&p_dev->dev));
if (!p_dev->devname)
goto err_free;
dev_dbg(&p_dev->dev, "devname is %s\n", p_dev->devname);
mutex_lock(&s->ops_mutex);
/*
* p_dev->function_config must be the same for all card functions.
* Note that this is serialized by ops_mutex, 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;
p_dev->irq = tmp_dev->irq;
kref_get(&p_dev->function_config->ref);
}
/* Add to the list in pcmcia_bus_socket */
list_add(&p_dev->socket_device_list, &s->devices_list);
if (pcmcia_setup_irq(p_dev))
dev_warn(&p_dev->dev,
"IRQ setup failed -- device might not work\n");
if (!p_dev->function_config) {
config_t *c;
dev_dbg(&p_dev->dev, "creating config_t\n");
c = kzalloc(sizeof(struct config_t), GFP_KERNEL);
if (!c) {
mutex_unlock(&s->ops_mutex);
goto err_unreg;
}
p_dev->function_config = c;
kref_init(&c->ref);
for (i = 0; i < MAX_IO_WIN; i++) {
c->io[i].name = p_dev->devname;
c->io[i].flags = IORESOURCE_IO;
}
for (i = 0; i< MAX_WIN; i++) {
c->mem[i].name = p_dev->devname;
c->mem[i].flags = IORESOURCE_MEM;
}
}
for (i = 0; i < MAX_IO_WIN; i++)
p_dev->resource[i] = &p_dev->function_config->io[i];
for (; i < (MAX_IO_WIN + MAX_WIN); i++)
p_dev->resource[i] = &p_dev->function_config->mem[i-MAX_IO_WIN];
mutex_unlock(&s->ops_mutex);
dev_printk(KERN_NOTICE, &p_dev->dev,
"pcmcia: registering new device %s (IRQ: %d)\n",
p_dev->devname, p_dev->irq);
pcmcia_device_query(p_dev);
if (device_register(&p_dev->dev))
goto err_unreg;
return p_dev;
err_unreg:
mutex_lock(&s->ops_mutex);
list_del(&p_dev->socket_device_list);
mutex_unlock(&s->ops_mutex);
err_free:
mutex_lock(&s->ops_mutex);
s->device_count--;
mutex_unlock(&s->ops_mutex);
for (i = 0; i < 4; i++)
kfree(p_dev->prod_id[i]);
kfree(p_dev->devname);
kfree(p_dev);
err_put:
pcmcia_put_socket(s);
return NULL;
}
static int pcmcia_card_add(struct pcmcia_socket *s)
{
cistpl_longlink_mfc_t mfc;
unsigned int no_funcs, i, no_chains;
int ret = -EAGAIN;
mutex_lock(&s->ops_mutex);
if (!(s->resource_setup_done)) {
dev_dbg(&s->dev,
"no resources available, delaying card_add\n");
mutex_unlock(&s->ops_mutex);
return -EAGAIN; /* try again, but later... */
}
if (pcmcia_validate_mem(s)) {
dev_dbg(&s->dev, "validating mem resources failed, "
"delaying card_add\n");
mutex_unlock(&s->ops_mutex);
return -EAGAIN; /* try again, but later... */
}
mutex_unlock(&s->ops_mutex);
ret = pccard_validate_cis(s, &no_chains);
if (ret || !no_chains) {
dev_dbg(&s->dev, "invalid CIS or invalid resources\n");
return -ENODEV;
}
if (!pccard_read_tuple(s, BIND_FN_ALL, CISTPL_LONGLINK_MFC, &mfc))
no_funcs = mfc.nfn;
else
no_funcs = 1;
s->functions = no_funcs;
for (i = 0; i < no_funcs; i++)
pcmcia_device_add(s, i);
return ret;
}
static int pcmcia_requery_callback(struct device *dev, void * _data)
{
struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
if (!p_dev->dev.driver) {
dev_dbg(dev, "update device information\n");
pcmcia_device_query(p_dev);
}
return 0;
}
static void pcmcia_requery(struct pcmcia_socket *s)
{
int has_pfc;
if (s->functions == 0) {
pcmcia_card_add(s);
return;
}
/* some device information might have changed because of a CIS
* update or because we can finally read it correctly... so
* determine it again, overwriting old values if necessary. */
bus_for_each_dev(&pcmcia_bus_type, NULL, NULL, pcmcia_requery_callback);
/* if the CIS changed, we need to check whether the number of
* functions changed. */
if (s->fake_cis) {
int old_funcs, new_funcs;
cistpl_longlink_mfc_t mfc;
/* does this cis override add or remove functions? */
old_funcs = s->functions;
if (!pccard_read_tuple(s, BIND_FN_ALL, CISTPL_LONGLINK_MFC,
&mfc))
new_funcs = mfc.nfn;
else
new_funcs = 1;
if (old_funcs != new_funcs) {
/* we need to re-start */
pcmcia_card_remove(s, NULL);
s->functions = 0;
pcmcia_card_add(s);
}
}
/* If the PCMCIA device consists of two pseudo devices,
* call pcmcia_device_add() -- which will fail if both
* devices are already registered. */
mutex_lock(&s->ops_mutex);
has_pfc = s->pcmcia_pfc;
mutex_unlock(&s->ops_mutex);
if (has_pfc)
pcmcia_device_add(s, 0);
/* we re-scan all devices, not just the ones connected to this
* socket. This does not matter, though. */
if (bus_rescan_devices(&pcmcia_bus_type))
dev_warn(&s->dev, "rescanning the bus failed\n");
}
#ifdef CONFIG_PCMCIA_LOAD_CIS
/**
* pcmcia_load_firmware - load CIS from userspace if device-provided is broken
* @dev: the pcmcia device which needs a CIS override
* @filename: requested filename in /lib/firmware/
*
* This uses the in-kernel firmware loading mechanism to use a "fake CIS" if
* the one provided by the card is broken. The firmware files reside in
* /lib/firmware/ in userspace.
*/
static int pcmcia_load_firmware(struct pcmcia_device *dev, char * filename)
{
struct pcmcia_socket *s = dev->socket;
const struct firmware *fw;
int ret = -ENOMEM;
cistpl_longlink_mfc_t mfc;
int old_funcs, new_funcs = 1;
if (!filename)
return -EINVAL;
dev_dbg(&dev->dev, "trying to load CIS file %s\n", filename);
if (request_firmware(&fw, filename, &dev->dev) == 0) {
if (fw->size >= CISTPL_MAX_CIS_SIZE) {
ret = -EINVAL;
dev_printk(KERN_ERR, &dev->dev,
"pcmcia: CIS override is too big\n");
goto release;
}
if (!pcmcia_replace_cis(s, fw->data, fw->size))
ret = 0;
else {
dev_printk(KERN_ERR, &dev->dev,
"pcmcia: CIS override failed\n");
goto release;
}
/* we need to re-start if the number of functions changed */
old_funcs = s->functions;
if (!pccard_read_tuple(s, BIND_FN_ALL, CISTPL_LONGLINK_MFC,
&mfc))
new_funcs = mfc.nfn;
if (old_funcs != new_funcs)
ret = -EBUSY;
/* update information */
pcmcia_device_query(dev);
/* requery (as number of functions might have changed) */
pcmcia_parse_uevents(s, PCMCIA_UEVENT_REQUERY);
}
release:
release_firmware(fw);
return ret;
}
#else /* !CONFIG_PCMCIA_LOAD_CIS */
static inline int pcmcia_load_firmware(struct pcmcia_device *dev, char * filename)
{
return -ENODEV;
}
#endif
static inline int pcmcia_devmatch(struct pcmcia_device *dev,
const struct pcmcia_device_id *did)
{
if (did->match_flags & PCMCIA_DEV_ID_MATCH_MANF_ID) {
if ((!dev->has_manf_id) || (dev->manf_id != did->manf_id))
return 0;
}
if (did->match_flags & PCMCIA_DEV_ID_MATCH_CARD_ID) {
if ((!dev->has_card_id) || (dev->card_id != did->card_id))
return 0;
}
if (did->match_flags & PCMCIA_DEV_ID_MATCH_FUNCTION) {
if (dev->func != did->function)
return 0;
}
if (did->match_flags & PCMCIA_DEV_ID_MATCH_PROD_ID1) {
if (!dev->prod_id[0])
return 0;
if (strcmp(did->prod_id[0], dev->prod_id[0]))
return 0;
}
if (did->match_flags & PCMCIA_DEV_ID_MATCH_PROD_ID2) {
if (!dev->prod_id[1])
return 0;
if (strcmp(did->prod_id[1], dev->prod_id[1]))
return 0;
}
if (did->match_flags & PCMCIA_DEV_ID_MATCH_PROD_ID3) {
if (!dev->prod_id[2])
return 0;
if (strcmp(did->prod_id[2], dev->prod_id[2]))
return 0;
}
if (did->match_flags & PCMCIA_DEV_ID_MATCH_PROD_ID4) {
if (!dev->prod_id[3])
return 0;
if (strcmp(did->prod_id[3], dev->prod_id[3]))
return 0;
}
if (did->match_flags & PCMCIA_DEV_ID_MATCH_DEVICE_NO) {
dev_dbg(&dev->dev, "this is a pseudo-multi-function device\n");
mutex_lock(&dev->socket->ops_mutex);
dev->socket->pcmcia_pfc = 1;
mutex_unlock(&dev->socket->ops_mutex);
if (dev->device_no != did->device_no)
return 0;
}
if (did->match_flags & PCMCIA_DEV_ID_MATCH_FUNC_ID) {
int ret;
if ((!dev->has_func_id) || (dev->func_id != did->func_id))
return 0;
/* if this is a pseudo-multi-function device,
* we need explicit matches */
if (dev->socket->pcmcia_pfc)
return 0;
if (dev->device_no)
return 0;
/* also, FUNC_ID matching needs to be activated by userspace
* after it has re-checked that there is no possible module
* with a prod_id/manf_id/card_id match.
*/
mutex_lock(&dev->socket->ops_mutex);
ret = dev->allow_func_id_match;
mutex_unlock(&dev->socket->ops_mutex);
if (!ret) {
dev_dbg(&dev->dev,
"skipping FUNC_ID match until userspace ACK\n");
return 0;
}
}
if (did->match_flags & PCMCIA_DEV_ID_MATCH_FAKE_CIS) {
dev_dbg(&dev->dev, "device needs a fake CIS\n");
if (!dev->socket->fake_cis)
if (pcmcia_load_firmware(dev, did->cisfile))
return 0;
}
if (did->match_flags & PCMCIA_DEV_ID_MATCH_ANONYMOUS) {
int i;
for (i = 0; i < 4; i++)
if (dev->prod_id[i])
return 0;
if (dev->has_manf_id || dev->has_card_id || dev->has_func_id)
return 0;
}
return 1;
}
static int pcmcia_bus_match(struct device *dev, struct device_driver *drv)
{
struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
struct pcmcia_driver *p_drv = to_pcmcia_drv(drv);
const struct pcmcia_device_id *did = p_drv->id_table;
struct pcmcia_dynid *dynid;
/* match dynamic devices first */
mutex_lock(&p_drv->dynids.lock);
list_for_each_entry(dynid, &p_drv->dynids.list, node) {
dev_dbg(dev, "trying to match to %s\n", drv->name);
if (pcmcia_devmatch(p_dev, &dynid->id)) {
dev_dbg(dev, "matched to %s\n", drv->name);
mutex_unlock(&p_drv->dynids.lock);
return 1;
}
}
mutex_unlock(&p_drv->dynids.lock);
while (did && did->match_flags) {
dev_dbg(dev, "trying to match to %s\n", drv->name);
if (pcmcia_devmatch(p_dev, did)) {
dev_dbg(dev, "matched to %s\n", drv->name);
return 1;
}
did++;
}
return 0;
}
#ifdef CONFIG_HOTPLUG
static int pcmcia_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct pcmcia_device *p_dev;
int i;
u32 hash[4] = { 0, 0, 0, 0};
if (!dev)
return -ENODEV;
p_dev = to_pcmcia_dev(dev);
/* calculate hashes */
for (i = 0; i < 4; i++) {
if (!p_dev->prod_id[i])
continue;
hash[i] = crc32(0, p_dev->prod_id[i], strlen(p_dev->prod_id[i]));
}
if (add_uevent_var(env, "SOCKET_NO=%u", p_dev->socket->sock))
return -ENOMEM;
if (add_uevent_var(env, "DEVICE_NO=%02X", p_dev->device_no))
return -ENOMEM;
if (add_uevent_var(env, "MODALIAS=pcmcia:m%04Xc%04Xf%02Xfn%02Xpfn%02X"
"pa%08Xpb%08Xpc%08Xpd%08X",
p_dev->has_manf_id ? p_dev->manf_id : 0,
p_dev->has_card_id ? p_dev->card_id : 0,
p_dev->has_func_id ? p_dev->func_id : 0,
p_dev->func,
p_dev->device_no,
hash[0],
hash[1],
hash[2],
hash[3]))
return -ENOMEM;
return 0;
}
#else
static int pcmcia_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
{
return -ENODEV;
}
#endif
/************************ runtime PM support ***************************/
static int pcmcia_dev_suspend(struct device *dev, pm_message_t state);
static int pcmcia_dev_resume(struct device *dev);
static int runtime_suspend(struct device *dev)
{
int rc;
device_lock(dev);
rc = pcmcia_dev_suspend(dev, PMSG_SUSPEND);
device_unlock(dev);
return rc;
}
static int runtime_resume(struct device *dev)
{
int rc;
device_lock(dev);
rc = pcmcia_dev_resume(dev);
device_unlock(dev);
return rc;
}
/************************ per-device sysfs output ***************************/
#define pcmcia_device_attr(field, test, format) \
static ssize_t field##_show (struct device *dev, struct device_attribute *attr, char *buf) \
{ \
struct pcmcia_device *p_dev = to_pcmcia_dev(dev); \
return p_dev->test ? sprintf(buf, format, p_dev->field) : -ENODEV; \
}
#define pcmcia_device_stringattr(name, field) \
static ssize_t name##_show (struct device *dev, struct device_attribute *attr, char *buf) \
{ \
struct pcmcia_device *p_dev = to_pcmcia_dev(dev); \
return p_dev->field ? sprintf(buf, "%s\n", p_dev->field) : -ENODEV; \
}
pcmcia_device_attr(func, socket, "0x%02x\n");
pcmcia_device_attr(func_id, has_func_id, "0x%02x\n");
pcmcia_device_attr(manf_id, has_manf_id, "0x%04x\n");
pcmcia_device_attr(card_id, has_card_id, "0x%04x\n");
pcmcia_device_stringattr(prod_id1, prod_id[0]);
pcmcia_device_stringattr(prod_id2, prod_id[1]);
pcmcia_device_stringattr(prod_id3, prod_id[2]);
pcmcia_device_stringattr(prod_id4, prod_id[3]);
static ssize_t pcmcia_show_resources(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
char *str = buf;
int i;
for (i = 0; i < PCMCIA_NUM_RESOURCES; i++)
str += sprintf(str, "%pr\n", p_dev->resource[i]);
return str - buf;
}
static ssize_t pcmcia_show_pm_state(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
if (p_dev->suspended)
return sprintf(buf, "off\n");
else
return sprintf(buf, "on\n");
}
static ssize_t pcmcia_store_pm_state(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
int ret = 0;
if (!count)
return -EINVAL;
if ((!p_dev->suspended) && !strncmp(buf, "off", 3))
ret = runtime_suspend(dev);
else if (p_dev->suspended && !strncmp(buf, "on", 2))
ret = runtime_resume(dev);
return ret ? ret : count;
}
static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
int i;
u32 hash[4] = { 0, 0, 0, 0};
/* calculate hashes */
for (i = 0; i < 4; i++) {
if (!p_dev->prod_id[i])
continue;
hash[i] = crc32(0, p_dev->prod_id[i],
strlen(p_dev->prod_id[i]));
}
return sprintf(buf, "pcmcia:m%04Xc%04Xf%02Xfn%02Xpfn%02X"
"pa%08Xpb%08Xpc%08Xpd%08X\n",
p_dev->has_manf_id ? p_dev->manf_id : 0,
p_dev->has_card_id ? p_dev->card_id : 0,
p_dev->has_func_id ? p_dev->func_id : 0,
p_dev->func, p_dev->device_no,
hash[0], hash[1], hash[2], hash[3]);
}
static ssize_t pcmcia_store_allow_func_id_match(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
if (!count)
return -EINVAL;
mutex_lock(&p_dev->socket->ops_mutex);
p_dev->allow_func_id_match = 1;
mutex_unlock(&p_dev->socket->ops_mutex);
pcmcia_parse_uevents(p_dev->socket, PCMCIA_UEVENT_REQUERY);
return count;
}
static struct device_attribute pcmcia_dev_attrs[] = {
__ATTR(function, 0444, func_show, NULL),
__ATTR(pm_state, 0644, pcmcia_show_pm_state, pcmcia_store_pm_state),
__ATTR(resources, 0444, pcmcia_show_resources, NULL),
__ATTR_RO(func_id),
__ATTR_RO(manf_id),
__ATTR_RO(card_id),
__ATTR_RO(prod_id1),
__ATTR_RO(prod_id2),
__ATTR_RO(prod_id3),
__ATTR_RO(prod_id4),
__ATTR_RO(modalias),
__ATTR(allow_func_id_match, 0200, NULL, pcmcia_store_allow_func_id_match),
__ATTR_NULL,
};
/* PM support, also needed for reset */
static int pcmcia_dev_suspend(struct device *dev, pm_message_t state)
{
struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
struct pcmcia_driver *p_drv = NULL;
int ret = 0;
mutex_lock(&p_dev->socket->ops_mutex);
if (p_dev->suspended) {
mutex_unlock(&p_dev->socket->ops_mutex);
return 0;
}
p_dev->suspended = 1;
mutex_unlock(&p_dev->socket->ops_mutex);
dev_dbg(dev, "suspending\n");
if (dev->driver)
p_drv = to_pcmcia_drv(dev->driver);
if (!p_drv)
goto out;
if (p_drv->suspend) {
ret = p_drv->suspend(p_dev);
if (ret) {
dev_printk(KERN_ERR, dev,
"pcmcia: device %s (driver %s) did "
"not want to go to sleep (%d)\n",
p_dev->devname, p_drv->name, ret);
mutex_lock(&p_dev->socket->ops_mutex);
p_dev->suspended = 0;
mutex_unlock(&p_dev->socket->ops_mutex);
goto out;
}
}
if (p_dev->device_no == p_dev->func) {
dev_dbg(dev, "releasing configuration\n");
pcmcia_release_configuration(p_dev);
}
out:
return ret;
}
static int pcmcia_dev_resume(struct device *dev)
{
struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
struct pcmcia_driver *p_drv = NULL;
int ret = 0;
mutex_lock(&p_dev->socket->ops_mutex);
if (!p_dev->suspended) {
mutex_unlock(&p_dev->socket->ops_mutex);
return 0;
}
p_dev->suspended = 0;
mutex_unlock(&p_dev->socket->ops_mutex);
dev_dbg(dev, "resuming\n");
if (dev->driver)
p_drv = to_pcmcia_drv(dev->driver);
if (!p_drv)
goto out;
if (p_dev->device_no == p_dev->func) {
dev_dbg(dev, "requesting configuration\n");
ret = pcmcia_enable_device(p_dev);
if (ret)
goto out;
}
if (p_drv->resume)
ret = p_drv->resume(p_dev);
out:
return ret;
}
static int pcmcia_bus_suspend_callback(struct device *dev, void * _data)
{
struct pcmcia_socket *skt = _data;
struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
if (p_dev->socket != skt || p_dev->suspended)
return 0;
return runtime_suspend(dev);
}
static int pcmcia_bus_resume_callback(struct device *dev, void * _data)
{
struct pcmcia_socket *skt = _data;
struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
if (p_dev->socket != skt || !p_dev->suspended)
return 0;
runtime_resume(dev);
return 0;
}
static int pcmcia_bus_resume(struct pcmcia_socket *skt)
{
dev_dbg(&skt->dev, "resuming socket %d\n", skt->sock);
bus_for_each_dev(&pcmcia_bus_type, NULL, skt, pcmcia_bus_resume_callback);
return 0;
}
static int pcmcia_bus_suspend(struct pcmcia_socket *skt)
{
dev_dbg(&skt->dev, "suspending socket %d\n", skt->sock);
if (bus_for_each_dev(&pcmcia_bus_type, NULL, skt,
pcmcia_bus_suspend_callback)) {
pcmcia_bus_resume(skt);
return -EIO;
}
return 0;
}
static int pcmcia_bus_remove(struct pcmcia_socket *skt)
{
atomic_set(&skt->present, 0);
pcmcia_card_remove(skt, NULL);
mutex_lock(&skt->ops_mutex);
destroy_cis_cache(skt);
pcmcia_cleanup_irq(skt);
mutex_unlock(&skt->ops_mutex);
return 0;
}
static int pcmcia_bus_add(struct pcmcia_socket *skt)
{
atomic_set(&skt->present, 1);
mutex_lock(&skt->ops_mutex);
skt->pcmcia_pfc = 0;
destroy_cis_cache(skt); /* to be on the safe side... */
mutex_unlock(&skt->ops_mutex);
pcmcia_card_add(skt);
return 0;
}
static int pcmcia_bus_early_resume(struct pcmcia_socket *skt)
{
if (!verify_cis_cache(skt))
return 0;
dev_dbg(&skt->dev, "cis mismatch - different card\n");
/* first, remove the card */
pcmcia_bus_remove(skt);
mutex_lock(&skt->ops_mutex);
destroy_cis_cache(skt);
kfree(skt->fake_cis);
skt->fake_cis = NULL;
skt->functions = 0;
mutex_unlock(&skt->ops_mutex);
/* now, add the new card */
pcmcia_bus_add(skt);
return 0;
}
/*
* NOTE: This is racy. There's no guarantee the card will still be
* physically present, even if the call to this function returns
* non-NULL. Furthermore, the device driver most likely is unbound
* almost immediately, so the timeframe where pcmcia_dev_present
* returns NULL is probably really really small.
*/
struct pcmcia_device *pcmcia_dev_present(struct pcmcia_device *_p_dev)
{
struct pcmcia_device *p_dev;
struct pcmcia_device *ret = NULL;
p_dev = pcmcia_get_dev(_p_dev);
if (!p_dev)
return NULL;
if (atomic_read(&p_dev->socket->present) != 0)
ret = p_dev;
pcmcia_put_dev(p_dev);
return ret;
}
EXPORT_SYMBOL(pcmcia_dev_present);
static struct pcmcia_callback pcmcia_bus_callback = {
.owner = THIS_MODULE,
.add = pcmcia_bus_add,
.remove = pcmcia_bus_remove,
.requery = pcmcia_requery,
.validate = pccard_validate_cis,
.suspend = pcmcia_bus_suspend,
.early_resume = pcmcia_bus_early_resume,
.resume = pcmcia_bus_resume,
};
static int __devinit pcmcia_bus_add_socket(struct device *dev,
struct class_interface *class_intf)
{
struct pcmcia_socket *socket = dev_get_drvdata(dev);
int ret;
socket = pcmcia_get_socket(socket);
if (!socket) {
dev_printk(KERN_ERR, dev,
"PCMCIA obtaining reference to socket failed\n");
return -ENODEV;
}
ret = sysfs_create_bin_file(&dev->kobj, &pccard_cis_attr);
if (ret) {
dev_printk(KERN_ERR, dev, "PCMCIA registration failed\n");
pcmcia_put_socket(socket);
return ret;
}
INIT_LIST_HEAD(&socket->devices_list);
socket->pcmcia_pfc = 0;
socket->device_count = 0;
atomic_set(&socket->present, 0);
ret = pccard_register_pcmcia(socket, &pcmcia_bus_callback);
if (ret) {
dev_printk(KERN_ERR, dev, "PCMCIA registration failed\n");
pcmcia_put_socket(socket);
return ret;
}
return 0;
}
static void pcmcia_bus_remove_socket(struct device *dev,
struct class_interface *class_intf)
{
struct pcmcia_socket *socket = dev_get_drvdata(dev);
if (!socket)
return;
pccard_register_pcmcia(socket, NULL);
/* unregister any unbound devices */
mutex_lock(&socket->skt_mutex);
pcmcia_card_remove(socket, NULL);
release_cis_mem(socket);
mutex_unlock(&socket->skt_mutex);
sysfs_remove_bin_file(&dev->kobj, &pccard_cis_attr);
pcmcia_put_socket(socket);
return;
}
/* the pcmcia_bus_interface is used to handle pcmcia socket devices */
static struct class_interface pcmcia_bus_interface __refdata = {
.class = &pcmcia_socket_class,
.add_dev = &pcmcia_bus_add_socket,
.remove_dev = &pcmcia_bus_remove_socket,
};
struct bus_type pcmcia_bus_type = {
.name = "pcmcia",
.uevent = pcmcia_bus_uevent,
.match = pcmcia_bus_match,
.dev_attrs = pcmcia_dev_attrs,
.probe = pcmcia_device_probe,
.remove = pcmcia_device_remove,
.suspend = pcmcia_dev_suspend,
.resume = pcmcia_dev_resume,
};
static int __init init_pcmcia_bus(void)
{
int ret;
ret = bus_register(&pcmcia_bus_type);
if (ret < 0) {
printk(KERN_WARNING "pcmcia: bus_register error: %d\n", ret);
return ret;
}
ret = class_interface_register(&pcmcia_bus_interface);
if (ret < 0) {
printk(KERN_WARNING
"pcmcia: class_interface_register error: %d\n", ret);
bus_unregister(&pcmcia_bus_type);
return ret;
}
return 0;
}
fs_initcall(init_pcmcia_bus); /* one level after subsys_initcall so that
* pcmcia_socket_class is already registered */
static void __exit exit_pcmcia_bus(void)
{
class_interface_unregister(&pcmcia_bus_interface);
bus_unregister(&pcmcia_bus_type);
}
module_exit(exit_pcmcia_bus);
MODULE_ALIAS("ds");