mca: add integrated device bus matching

The MCA bus has a few "integrated" functions, which are effectively virtual
slots on the bus. The problem is that these special functions don't have
dedicated pos IDs, so we have to manufacture ids for them outside the pos
space ... and these ids can't be matched by the standard matching function,
so add a special registration that requests a list of pos ids or a particular
integrated function.

Signed-off-by: James Bottomley <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/mca/mca-bus.c

···
 	struct mca_device *mca_dev = to_mca_device (dev);
 	struct mca_driver *mca_drv = to_mca_driver (drv);
 	const unsigned short *mca_ids = mca_drv->id_table;
-	int i;
+	int i = 0;
 
-	if (!mca_ids)
-		return 0;
-
-	for(i = 0; mca_ids[i]; i++) {
-		if (mca_ids[i] == mca_dev->pos_id) {
-			mca_dev->index = i;
-			return 1;
+	if (mca_ids) {
+		for(i = 0; mca_ids[i]; i++) {
+			if (mca_ids[i] == mca_dev->pos_id) {
+				mca_dev->index = i;
+				return 1;
+			}
 		}
 	}
-
+	/* If the integrated id is present, treat it as though it were an
+	 * additional id in the id_table (it can't be because by definition,
+	 * integrated id's overflow a short */
+	if (mca_drv->integrated_id && mca_dev->pos_id ==
+	    mca_drv->integrated_id) {
+		mca_dev->index = i;
+		return 1;
+	}
 	return 0;
 }
 

drivers/mca/mca-driver.c

···
 		mca_drv->driver.bus = &mca_bus_type;
 		if ((r = driver_register(&mca_drv->driver)) < 0)
 			return r;
+		mca_drv->integrated_id = 0;
 	}
 
 	return 0;
 }
 EXPORT_SYMBOL(mca_register_driver);
+
+int mca_register_driver_integrated(struct mca_driver *mca_driver,
+				   int integrated_id)
+{
+	int r = mca_register_driver(mca_driver);
+
+	if (!r)
+		mca_driver->integrated_id = integrated_id;
+
+	return r;
+}
+EXPORT_SYMBOL(mca_register_driver_integrated);
 
 void mca_unregister_driver(struct mca_driver *mca_drv)
 {

include/linux/mca.h

···
 struct mca_driver {
 	const short		*id_table;
 	void			*driver_data;
+	int			integrated_id;
 	struct device_driver	driver;
 };
 #define to_mca_driver(mdriver) container_of(mdriver, struct mca_driver, driver)
···
 extern struct bus_type mca_bus_type;
 
 extern int mca_register_driver(struct mca_driver *drv);
+extern int mca_register_driver_integrated(struct mca_driver *, int);
 extern void mca_unregister_driver(struct mca_driver *drv);
 
 /* WARNING: only called by the boot time device setup */