PCI/IB: add support for pci driver attribute groups

Some drivers (specifically the nes IB driver), want to create a lot of
sysfs driver attributes.  Instead of open-coding the creation and
removal of these files (and getting it wrong btw), it's a better idea to
let the driver core handle all of this logic for us.

So add a new field to the pci driver structure, **groups, that allows
pci drivers to specify an attribute group list it wishes to have created
when it is registered with the driver core.

Big bonus is now the driver doesn't race with userspace when the sysfs
files are created vs. when the kobject is announced, so any script/tool
that actually wanted to use these files will not have to poll waiting
for them to show up.

Cc: Faisal Latif <faisal.latif@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/nes/nes.c

@@ -808,13 +808,6 @@ static void nes_remove(struct pci_dev *pcidev)
 }
 
 
-static struct pci_driver nes_pci_driver = {
-	.name = DRV_NAME,
-	.id_table = nes_pci_table,
-	.probe = nes_probe,
-	.remove = nes_remove,
-};
-
 static ssize_t adapter_show(struct device_driver *ddp, char *buf)
 {
 	unsigned int  devfn = 0xffffffff;
@@ -1156,35 +1149,29 @@ static DRIVER_ATTR_RW(idx_addr);
 static DRIVER_ATTR_RW(idx_data);
 static DRIVER_ATTR_RW(wqm_quanta);
 
-static int nes_create_driver_sysfs(struct pci_driver *drv)
+static struct attribute *nes_attrs[] = {
-{
+	&driver_attr_adapter.attr,
-	int error;
+	&driver_attr_eeprom_cmd.attr,
-	error  = driver_create_file(&drv->driver, &driver_attr_adapter);
+	&driver_attr_eeprom_data.attr,
-	error |= driver_create_file(&drv->driver, &driver_attr_eeprom_cmd);
+	&driver_attr_flash_cmd.attr,
-	error |= driver_create_file(&drv->driver, &driver_attr_eeprom_data);
+	&driver_attr_flash_data.attr,
-	error |= driver_create_file(&drv->driver, &driver_attr_flash_cmd);
+	&driver_attr_nonidx_addr.attr,
-	error |= driver_create_file(&drv->driver, &driver_attr_flash_data);
+	&driver_attr_nonidx_data.attr,
-	error |= driver_create_file(&drv->driver, &driver_attr_nonidx_addr);
+	&driver_attr_idx_addr.attr,
-	error |= driver_create_file(&drv->driver, &driver_attr_nonidx_data);
+	&driver_attr_idx_data.attr,
-	error |= driver_create_file(&drv->driver, &driver_attr_idx_addr);
+	&driver_attr_wqm_quanta.attr,
-	error |= driver_create_file(&drv->driver, &driver_attr_idx_data);
+	NULL,
-	error |= driver_create_file(&drv->driver, &driver_attr_wqm_quanta);
+};
-	return error;
+ATTRIBUTE_GROUPS(nes);
-}
+
+static struct pci_driver nes_pci_driver = {
+	.name = DRV_NAME,
+	.id_table = nes_pci_table,
+	.probe = nes_probe,
+	.remove = nes_remove,
+	.groups = nes_groups,
+};
 
-static void nes_remove_driver_sysfs(struct pci_driver *drv)
-{
-	driver_remove_file(&drv->driver, &driver_attr_adapter);
-	driver_remove_file(&drv->driver, &driver_attr_eeprom_cmd);
-	driver_remove_file(&drv->driver, &driver_attr_eeprom_data);
-	driver_remove_file(&drv->driver, &driver_attr_flash_cmd);
-	driver_remove_file(&drv->driver, &driver_attr_flash_data);
-	driver_remove_file(&drv->driver, &driver_attr_nonidx_addr);
-	driver_remove_file(&drv->driver, &driver_attr_nonidx_data);
-	driver_remove_file(&drv->driver, &driver_attr_idx_addr);
-	driver_remove_file(&drv->driver, &driver_attr_idx_data);
-	driver_remove_file(&drv->driver, &driver_attr_wqm_quanta);
-}
 
 /**
  * nes_init_module - module initialization entry point
@@ -1192,20 +1179,13 @@ static void nes_remove_driver_sysfs(struct pci_driver *drv)
 static int __init nes_init_module(void)
 {
 	int retval;
-	int retval1;
 
 	retval = nes_cm_start();
 	if (retval) {
 		printk(KERN_ERR PFX "Unable to start NetEffect iWARP CM.\n");
 		return retval;
 	}
-	retval = pci_register_driver(&nes_pci_driver);
+	return pci_register_driver(&nes_pci_driver);
-	if (retval >= 0) {
-		retval1 = nes_create_driver_sysfs(&nes_pci_driver);
-		if (retval1 < 0)
-			printk(KERN_ERR PFX "Unable to create NetEffect sys files.\n");
-	}
-	return retval;
 }
 
 
@@ -1215,7 +1195,6 @@ static int __init nes_init_module(void)
 static void __exit nes_exit_module(void)
 {
 	nes_cm_stop();
-	nes_remove_driver_sysfs(&nes_pci_driver);
 
 	pci_unregister_driver(&nes_pci_driver);
 }

drivers/pci/pci-driver.c

@@ -1307,6 +1307,7 @@ int __pci_register_driver(struct pci_driver *drv, struct module *owner,
 	drv->driver.bus = &pci_bus_type;
 	drv->driver.owner = owner;
 	drv->driver.mod_name = mod_name;
+	drv->driver.groups = drv->groups;
 
 	spin_lock_init(&drv->dynids.lock);
 	INIT_LIST_HEAD(&drv->dynids.list);

include/linux/pci.h

@@ -729,6 +729,7 @@ struct pci_driver {
 	void (*shutdown) (struct pci_dev *dev);
 	int (*sriov_configure) (struct pci_dev *dev, int num_vfs); /* PF pdev */
 	const struct pci_error_handlers *err_handler;
+	const struct attribute_group **groups;
 	struct device_driver	driver;
 	struct pci_dynids dynids;
 };