RE: PCI/IB: add support for pci driver attribute groups

[Latif, Faisal]

Thanks!
Faisal

>-----Original Message-----
>From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx]
>Sent: Wednesday, July 19, 2017 8:01 AM
>To: Latif, Faisal <faisal.latif@xxxxxxxxx>; Doug Ledford
><dledford@xxxxxxxxxx>; Hefty, Sean <sean.hefty@xxxxxxxxx>; Hal Rosenstock
><hal.rosenstock@xxxxxxxxx>; Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>Cc: linux-rdma@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; linux-
>kernel@xxxxxxxxxxxxxxx
>Subject: PCI/IB: add support for pci driver attribute groups
>
>From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>
>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@xxxxxxxxx>
>Cc: Doug Ledford <dledford@xxxxxxxxxx>
>Cc: Sean Hefty <sean.hefty@xxxxxxxxx>
>Cc: Hal Rosenstock <hal.rosenstock@xxxxxxxxx>
>Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>
>---
> drivers/infiniband/hw/nes/nes.c |   69 +++++++++++++---------------------------
> drivers/pci/pci-driver.c        |    1
> include/linux/pci.h             |    1
> 3 files changed, 26 insertions(+), 45 deletions(-)
>
>--- a/drivers/infiniband/hw/nes/nes.c
>+++ b/drivers/infiniband/hw/nes/nes.c
>@@ -808,13 +808,6 @@ static void nes_remove(struct pci_dev *p  }
>
>
>-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) -{
>-	int error;
>-	error  = driver_create_file(&drv->driver, &driver_attr_adapter);
>-	error |= driver_create_file(&drv->driver, &driver_attr_eeprom_cmd);
>-	error |= driver_create_file(&drv->driver, &driver_attr_eeprom_data);
>-	error |= driver_create_file(&drv->driver, &driver_attr_flash_cmd);
>-	error |= driver_create_file(&drv->driver, &driver_attr_flash_data);
>-	error |= driver_create_file(&drv->driver, &driver_attr_nonidx_addr);
>-	error |= driver_create_file(&drv->driver, &driver_attr_nonidx_data);
>-	error |= driver_create_file(&drv->driver, &driver_attr_idx_addr);
>-	error |= driver_create_file(&drv->driver, &driver_attr_idx_data);
>-	error |= driver_create_file(&drv->driver, &driver_attr_wqm_quanta);
>-	return error;
>-}
>-
>-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);
>-}
>+static struct attribute *nes_attrs[] = {
>+	&driver_attr_adapter,
>+	&driver_attr_eeprom_cmd,
>+	&driver_attr_eeprom_data,
>+	&driver_attr_flash_cmd,
>+	&driver_attr_flash_data,
>+	&driver_attr_nonidx_addr,
>+	&driver_attr_nonidx_data,
>+	&driver_attr_idx_addr,
>+	&driver_attr_idx_data,
>+	&driver_attr_wqm_quanta,
>+	NULL,
>+};
>+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,
>+};
>+
>
> /**
>  * nes_init_module - module initialization entry point @@ -1192,20 +1179,13
>@@ static void nes_remove_driver_sysfs(stru  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);
>-	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;
>+	return pci_register_driver(&nes_pci_driver);
> }
>
>
>@@ -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);
> }
>--- a/drivers/pci/pci-driver.c
>+++ b/drivers/pci/pci-driver.c
>@@ -1307,6 +1307,7 @@ int __pci_register_driver(struct pci_dri
> 	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);
>--- a/include/linux/pci.h
>+++ b/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;
> };