On Wed, Aug 25, 2021 at 04:51:35PM +0300, Yishai Hadas wrote:
> From: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>
>
> Add 'override_only' field to struct pci_device_id to be used as part of
> pci_match_device().
>
> When set, it means that matching is true only when dev->driver_override
> is this driver.
Maybe:
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: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Signed-off-by: Yishai Hadas <yishaih@xxxxxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
> Documentation/PCI/pci.rst | 1 +
> drivers/pci/pci-driver.c | 28 +++++++++++++++++++++-------
> include/linux/mod_devicetable.h | 2 ++
> include/linux/pci.h | 15 +++++++++++++++
> 4 files changed, 39 insertions(+), 7 deletions(-)
>
> diff --git a/Documentation/PCI/pci.rst b/Documentation/PCI/pci.rst
> index fa651e25d98c..87c6f4a6ca32 100644
> --- a/Documentation/PCI/pci.rst
> +++ b/Documentation/PCI/pci.rst
> @@ -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
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index 3a72352aa5cf..123c590ebe1d 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -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);
> + if (found_id)
> + return found_id;
>
> - /* driver_override will always match, send a dummy id */
> - if (!found_id && dev->driver_override)
> - found_id = &pci_device_id_any;
> + 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;
> + }
> + }
>
> - return found_id;
> + /* driver_override will always match, send a dummy id */
> + if (dev->driver_override)
> + return &pci_device_id_any;
> + return NULL;
> }
>
> /**
> diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
> index 8e291cfdaf06..2e3ba6d9ece0 100644
> --- a/include/linux/mod_devicetable.h
> +++ b/include/linux/mod_devicetable.h
> @@ -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;
> };
>
>
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 540b377ca8f6..0506b1a8c921 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -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
> --
> 2.18.1
>
