Commit 343b7258 authored by Max Gurtovoy's avatar Max Gurtovoy Committed by Alex Williamson
Browse files

PCI: Add 'override_only' field to struct pci_device_id 



Add 'override_only' field to struct pci_device_id to be used as part of
pci_match_device().

When set, a driver only matches the entry when dev->driver_override is
set to that driver.

In addition, add a helper macro named 'PCI_DEVICE_DRIVER_OVERRIDE' to
enable setting some data on it.

Next patch from this series will use the above functionality.

Signed-off-by: default avatarMax Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarYishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20210826103912.128972-10-yishaih@nvidia.com


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent c61302aa

Documentation/PCI/pci.rst

+1 −0
Original line number Diff line number Diff line
@@ -103,6 +103,7 @@ need pass only as many optional fields as necessary: 
  - subvendor and subdevice fields default to PCI_ANY_ID (FFFFFFFF)

  - class and classmask fields default to 0

  - driver_data defaults to 0UL.

  - override_only field defaults to 0.



Note that driver_data must match the value used by any of the pci_device_id

entries defined in the driver. This makes the driver_data field mandatory

drivers/pci/pci-driver.c

+21 −7
Original line number Diff line number Diff line
@@ -136,7 +136,7 @@ static const struct pci_device_id *pci_match_device(struct pci_driver *drv, 
						    struct pci_dev *dev)

{

	struct pci_dynid *dynid;

	const struct pci_device_id *found_id = NULL;

	const struct pci_device_id *found_id = NULL, *ids;



	/* When driver_override is set, only bind to the matching driver */

	if (dev->driver_override && strcmp(dev->driver_override, drv->name))
@@ -152,14 +152,28 @@ static const struct pci_device_id *pci_match_device(struct pci_driver *drv, 
	}

	spin_unlock(&drv->dynids.lock);



	if (!found_id)

		found_id = pci_match_id(drv->id_table, dev);



	/* driver_override will always match, send a dummy id */

	if (!found_id && dev->driver_override)

		found_id = &pci_device_id_any;

	if (found_id)

		return found_id;



	for (ids = drv->id_table; (found_id = pci_match_id(ids, dev));

	     ids = found_id + 1) {

		/*

		 * The match table is split based on driver_override.

		 * In case override_only was set, enforce driver_override

		 * matching.

		 */

		if (found_id->override_only) {

			if (dev->driver_override)

				return found_id;

		} else {

			return found_id;

		}

	}



	/* driver_override will always match, send a dummy id */

	if (dev->driver_override)

		return &pci_device_id_any;

	return NULL;

}



/**

include/linux/mod_devicetable.h

+2 −0
Original line number Diff line number Diff line
@@ -34,12 +34,14 @@ typedef unsigned long kernel_ulong_t; 
 *			Best practice is to use driver_data as an index

 *			into a static list of equivalent device types,

 *			instead of using it as a pointer.

 * @override_only:	Match only when dev->driver_override is this driver.

 */

struct pci_device_id {

	__u32 vendor, device;		/* Vendor and device ID or PCI_ANY_ID*/

	__u32 subvendor, subdevice;	/* Subsystem ID's or PCI_ANY_ID */

	__u32 class, class_mask;	/* (class,subclass,prog-if) triplet */

	kernel_ulong_t driver_data;	/* Data private to the driver */

	__u32 override_only;

};

include/linux/pci.h

+15 −0
Original line number Diff line number Diff line
@@ -901,6 +901,21 @@ struct pci_driver { 
	.vendor = (vend), .device = (dev), \

	.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID



/**

 * PCI_DEVICE_DRIVER_OVERRIDE - macro used to describe a PCI device with

 *                              override_only flags.

 * @vend: the 16 bit PCI Vendor ID

 * @dev: the 16 bit PCI Device ID

 * @driver_override: the 32 bit PCI Device override_only

 *

 * This macro is used to create a struct pci_device_id that matches only a

 * driver_override device. The subvendor and subdevice fields will be set to

 * PCI_ANY_ID.

 */

#define PCI_DEVICE_DRIVER_OVERRIDE(vend, dev, driver_override) \

	.vendor = (vend), .device = (dev), .subvendor = PCI_ANY_ID, \

	.subdevice = PCI_ANY_ID, .override_only = (driver_override)



/**

 * PCI_DEVICE_SUB - macro used to describe a specific PCI device with subsystem

 * @vend: the 16 bit PCI Vendor ID