From 3ebe7f9f7e4a4fd1f6461ecd01ff2961317a483a Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Fri, 2 May 2014 10:40:42 -0600 Subject: PCI: Notify driver before and after device reset Notify a PCI device driver when its device's access is about to be disabled for an impending reset attempt, then after the attempt completes and device access is restored. The notification is via the pci_error_handlers interface. Signed-off-by: Keith Busch Signed-off-by: Bjorn Helgaas --- include/linux/pci.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/pci.h') diff --git a/include/linux/pci.h b/include/linux/pci.h index aab57b4abe7f..31c43093e538 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -603,6 +603,9 @@ struct pci_error_handlers { /* PCI slot has been reset */ pci_ers_result_t (*slot_reset)(struct pci_dev *dev); + /* PCI function reset prepare or completed */ + void (*reset_notify)(struct pci_dev *dev, bool prepare); + /* Device driver may resume normal operations */ void (*resume)(struct pci_dev *dev); }; -- cgit v1.2.1 From 1c86438c9423a26cc9f7f74a8950d9cf9c93bc23 Mon Sep 17 00:00:00 2001 From: Yijing Wang Date: Sun, 4 May 2014 12:23:37 +0800 Subject: PCI: Add new pci_is_bridge() interface Add a helper function to check a device's header type for PCI bridge or CardBus bridge. Requires: 326c1cdae741 PCI: Rename pci_is_bridge() to pci_has_subordinate() Signed-off-by: Yijing Wang Signed-off-by: Bjorn Helgaas --- include/linux/pci.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include/linux/pci.h') diff --git a/include/linux/pci.h b/include/linux/pci.h index aab57b4abe7f..f2a5946ea0bf 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -477,6 +477,19 @@ static inline bool pci_is_root_bus(struct pci_bus *pbus) return !(pbus->parent); } +/** + * pci_is_bridge - check if the PCI device is a bridge + * @dev: PCI device + * + * Return true if the PCI device is bridge whether it has subordinate + * or not. + */ +static inline bool pci_is_bridge(struct pci_dev *dev) +{ + return dev->hdr_type == PCI_HEADER_TYPE_BRIDGE || + dev->hdr_type == PCI_HEADER_TYPE_CARDBUS; +} + static inline struct pci_dev *pci_upstream_bridge(struct pci_dev *dev) { dev = pci_physfn(dev); -- cgit v1.2.1 From 782a985d7af26db39e86070d28f987cad21313c0 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Tue, 20 May 2014 08:53:21 -0600 Subject: PCI: Introduce new device binding path using pci_dev.driver_override The driver_override field allows us to specify the driver for a device rather than relying on the driver to provide a positive match of the device. This shortcuts the existing process of looking up the vendor and device ID, adding them to the driver new_id, binding the device, then removing the ID, but it also provides a couple advantages. First, the above existing process allows the driver to bind to any device matching the new_id for the window where it's enabled. This is often not desired, such as the case of trying to bind a single device to a meta driver like pci-stub or vfio-pci. Using driver_override we can do this deterministically using: echo pci-stub > /sys/bus/pci/devices/0000:03:00.0/driver_override echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind echo 0000:03:00.0 > /sys/bus/pci/drivers_probe Previously we could not invoke drivers_probe after adding a device to new_id for a driver as we get non-deterministic behavior whether the driver we intend or the standard driver will claim the device. Now it becomes a deterministic process, only the driver matching driver_override will probe the device. To return the device to the standard driver, we simply clear the driver_override and reprobe the device: echo > /sys/bus/pci/devices/0000:03:00.0/driver_override echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind echo 0000:03:00.0 > /sys/bus/pci/drivers_probe Another advantage to this approach is that we can specify a driver override to force a specific binding or prevent any binding. For instance when an IOMMU group is exposed to userspace through VFIO we require that all devices within that group are owned by VFIO. However, devices can be hot-added into an IOMMU group, in which case we want to prevent the device from binding to any driver (override driver = "none") or perhaps have it automatically bind to vfio-pci. With driver_override it's a simple matter for this field to be set internally when the device is first discovered to prevent driver matches. Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Alexander Graf Acked-by: Greg Kroah-Hartman --- include/linux/pci.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/pci.h') diff --git a/include/linux/pci.h b/include/linux/pci.h index aab57b4abe7f..b72af276f591 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -365,6 +365,7 @@ struct pci_dev { #endif phys_addr_t rom; /* Physical address of ROM if it's not from the BAR */ size_t romlen; /* Length of ROM if it's not from the BAR */ + char *driver_override; /* Driver name to force a match */ }; static inline struct pci_dev *pci_physfn(struct pci_dev *dev) -- cgit v1.2.1