[PATCH] pnpbios #12

Thomas Hood (jdthood@mail.com)
15 Nov 2001 09:54:55 -0500


Patch #12
- Put more of pnp_bios.h inside #ifdef __KERNEL__ ... #endif
- Remove unused pnpbios_module_init stuff from pnp_bios.h
- Make locking coarser. This is a first step toward making
the driver ready for hotplug. This is a non-trivial change.

In addition to #11:
- Minor formatting changes
- Use spin_lock_init() instead of "= SPIN_LOCK_UNLOCKED"
- Add some comments
- Don't export pnpbios_announce_device, which isn't
used by outsiders
- Don't spinlock when accessing info that doesn't change
- Update Christian Schmidt's e-mail address

The patch:
--- linux-2.4.13-ac8_ORIG/include/linux/pnp_bios.h Thu Nov 8 19:42:17 2001
+++ linux-2.4.13-ac8/include/linux/pnp_bios.h Wed Nov 14 10:59:44 2001
@@ -18,14 +18,13 @@
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * $Original Id: pnp-bios.h,v 0.1 1998/03/19 23:00:00 cs Exp $
- * pnp_bios.h,v 1.1 1999/08/04 15:56:03 root Exp
*/

#ifndef _LINUX_PNP_BIOS_H
#define _LINUX_PNP_BIOS_H

+#ifdef __KERNEL__
+
#include <linux/types.h>
#include <linux/pci.h>

@@ -109,8 +108,6 @@
};
#pragma pack()

-#ifdef __KERNEL__
-
struct pnpbios_device_id
{
char id[8];
@@ -125,24 +122,26 @@
void (*remove) (struct pci_dev *dev); /* Device removed, either due to hotplug remove or module remove */
};

-#define pnpbios_dev_g(n) list_entry(n, struct pci_dev, global_list)
-
-static __inline struct pnpbios_driver *pnpbios_dev_driver(const struct pci_dev *dev)
-{
- return (struct pnpbios_driver *)dev->driver;
-}
-
#ifdef CONFIG_PNPBIOS
-#define pnpbios_for_each_dev(dev) \
- for(dev = pnpbios_dev_g(pnpbios_devices.next); dev != pnpbios_dev_g(&pnpbios_devices); dev = pnpbios_dev_g(dev->global_list.next))

-/* exported functions */
+/* exported */
extern struct pci_dev *pnpbios_find_device(char *pnpid, struct pci_dev *prevdev);
extern int pnpbios_get_device(char *pnpid, int prevnodenum, struct pci_dev *dev);
extern int pnpbios_register_driver(struct pnpbios_driver *drv);
extern void pnpbios_unregister_driver(struct pnpbios_driver *drv);

-/* non-exported functions */
+/* non-exported */
+#define pnpbios_for_each_dev(dev) \
+ for(dev = pnpbios_dev_g(pnpbios_devices.next); dev != pnpbios_dev_g(&pnpbios_devices); dev = pnpbios_dev_g(dev->global_list.next))
+
+
+#define pnpbios_dev_g(n) list_entry(n, struct pci_dev, global_list)
+
+static __inline struct pnpbios_driver *pnpbios_dev_driver(const struct pci_dev *dev)
+{
+ return (struct pnpbios_driver *)dev->driver;
+}
+
extern int pnpbios_dont_use_current_config;
extern void *pnpbios_kmalloc(size_t size, int f);
extern void pnpbios_init (void);
@@ -197,9 +196,13 @@
}

#else /* CONFIG_PNPBIOS */
-#define pnpbios_for_each_dev(dev) for(dev = NULL; 0; )

-static __inline__ struct pci_dev *pnpbios_find_device(char *pnpid, struct pci_dev *dev)
+static __inline__ struct pci_dev *pnpbios_find_device(char *pnpid, struct pci_dev *prevdev)
+{
+ return NULL;
+}
+
+static __inline__ int pnpbios_get_device(char *pnpid, int prevnodenum, struct pci_dev *dev)
{
return NULL;
}
@@ -212,11 +215,6 @@
static __inline__ void pnpbios_unregister_driver(struct pnpbios_driver *drv)
{
return;
-}
-
-static __inline__ int pnpbios_module_init(struct pnpbios_driver *drv)
-{
- return -ENODEV;
}

#endif /* CONFIG_PNPBIOS */
--- linux-2.4.13-ac8_ORIG/drivers/pnp/pnp_bios.c Thu Nov 8 19:42:16 2001
+++ linux-2.4.13-ac8/drivers/pnp/pnp_bios.c Thu Nov 15 09:51:02 2001
@@ -940,23 +940,27 @@
*/
int pnpbios_get_device(char *pnpid, int prevnodenum, struct pci_dev *usrdev)
{
+ unsigned long flags;
struct pci_dev *dev;
+ int ret;

+ spin_lock_irqsave(&pnpbios_devices_lock, flags);
pnpbios_for_each_dev(dev) {
if((int)dev->devfn > prevnodenum && memcmp(dev->slot_name,pnpid,7)==0) {
- unsigned long flags;
/* We lock to prevent updates while we are making a copy */
- spin_lock_irqsave(&pnpbios_devices_lock, flags);
memcpy(usrdev,dev,sizeof(struct pci_dev));
- spin_unlock_irqrestore(&pnpbios_devices_lock, flags);
usrdev->global_list.prev = NULL;
usrdev->global_list.next = NULL;
- return (int)dev->devfn;
+ ret = (int)dev->devfn;
+ goto out;
}
}
-
/* Didn't got it */
- return -1;
+ ret = -1;
+out:
+ spin_unlock_irqrestore(&pnpbios_devices_lock, flags);
+
+ return ret;
}

EXPORT_SYMBOL(pnpbios_get_device);
@@ -975,15 +979,15 @@

static void pnpbios_update_devlist( u8 nodenum, struct pnp_bios_node *data )
{
+ unsigned long flags;
struct pci_dev *dev;

+ spin_lock_irqsave(&pnpbios_devices_lock, flags);
dev = pnpbios_find_device_by_nodenum( nodenum );
if ( dev ) {
- unsigned long flags;
- spin_lock_irqsave(&pnpbios_devices_lock, flags);
pnpbios_node_resource_data_to_dev(data,dev);
- spin_unlock_irqrestore(&pnpbios_devices_lock, flags);
}
+ spin_unlock_irqrestore(&pnpbios_devices_lock, flags);

return;
}
@@ -1000,17 +1004,6 @@

static LIST_HEAD(pnpbios_drivers);

-/**
- * pnpbios_match_device - Tell if a PnPBIOS device structure has
- * a matching PnPBIOS device id structure
- * @ids: array of PnPBIOS device id structures to search in
- * @dev: the PnPBIOS device structure to match against
- *
- * Used by a driver to check whether a PnPBIOS device present in the
- * system is in its list of supported devices.Returns the matching
- * pnpbios_device_id structure or %NULL if there is no match.
- */
-
static const struct pnpbios_device_id *
pnpbios_match_device(const struct pnpbios_device_id *ids, const struct pci_dev *dev)
{
@@ -1026,26 +1019,30 @@
static int pnpbios_announce_device(struct pnpbios_driver *drv, struct pci_dev *dev)
{
const struct pnpbios_device_id *id;
- int ret = 0;
+ struct pci_dev tmpdev;
+ int ret;

if (drv->id_table) {
id = pnpbios_match_device(drv->id_table, dev);
- if (!id) {
- ret = 0;
- goto out;
- }
+ if (!id)
+ return 0;
} else
id = NULL;

+ memcpy( &tmpdev, dev, sizeof(struct pci_dev));
+ tmpdev.global_list.prev = NULL;
+ tmpdev.global_list.next = NULL;
+
dev_probe_lock();
- if (drv->probe(dev, id) >= 0) {
- // Hack for 2.4 - in 2.5 this needs to be generic stuff anyway
- dev->driver = (void *)drv;
- ret = 1;
- }
+ /* Obviously, probe() should not call any pnpbios functions */
+ ret = drv->probe(&tmpdev, id);
dev_probe_unlock();
-out:
- return ret;
+ if (ret < 1)
+ return 0;
+
+ dev->driver = (void *)drv;
+
+ return 1;
}

/**
@@ -1053,6 +1050,15 @@
* @drv: the driver structure to register
*
* Adds the driver structure to the list of registered drivers
+ *
+ * For each device in the pnpbios device list that matches one of
+ * the ids in drv->id_table, calls the driver's "probe" function with
+ * arguments (1) a pointer to a *temporary* struct pci_dev containing
+ * resource info for the device, and (2) a pointer to the id string
+ * of the device. Expects the probe function to return 1 if the
+ * driver claims the device (otherwise 0) in which case, marks the
+ * device as having this driver.
+ *
* Returns the number of pci devices which were claimed by the driver
* during registration. The driver remains registered even if the
* return value is zero.
@@ -1061,13 +1067,16 @@
pnpbios_register_driver(struct pnpbios_driver *drv)
{
struct pci_dev *dev;
+ unsigned long flags;
int count = 0;

list_add_tail(&drv->node, &pnpbios_drivers);
+ spin_lock_irqsave(&pnpbios_devices_lock, flags);
pnpbios_for_each_dev(dev) {
if (!pnpbios_dev_driver(dev))
count += pnpbios_announce_device(drv, dev);
}
+ spin_unlock_irqrestore(&pnpbios_devices_lock, flags);
return count;
}

@@ -1077,17 +1086,19 @@
* pnpbios_unregister_driver - unregister a pci driver
* @drv: the driver structure to unregister
*
- * Deletes the driver structure from the list of registered PnPBIOS drivers,
- * gives it a chance to clean up by calling its remove() function for
- * each device it was responsible for, and marks those devices as
- * driverless.
+ * Deletes the driver structure from the list of registered PnPBIOS
+ * drivers, gives it a chance to clean up by calling its "remove"
+ * function for each device it was responsible for, and marks those
+ * devices as driverless.
*/
void
pnpbios_unregister_driver(struct pnpbios_driver *drv)
{
+ unsigned long flags;
struct pci_dev *dev;

list_del(&drv->node);
+ spin_lock_irqsave(&pnpbios_devices_lock, flags);
pnpbios_for_each_dev(dev) {
if (dev->driver == (void *)drv) {
if (drv->remove)
@@ -1095,6 +1106,7 @@
dev->driver = NULL;
}
}
+ spin_unlock_irqrestore(&pnpbios_devices_lock, flags);
}

EXPORT_SYMBOL(pnpbios_unregister_driver);

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