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OpenCloudOS-Kernel/arch/s390/pci/pci_bus.h

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s390/pci: create zPCI bus The zPCI bus is in charge to handle common zPCI resources for zPCI devices. Creating the zPCI bus, the PCI bus, the zPCI devices and the PCI devices and hotplug slots done in a specific order: - PCI hotplug slot creation needs a PCI bus - PCI bus needs a PCI domain which is reported by the pci_domain_nr() when setting up the host bridge - PCI domain is set from the zPCI with devfn 0 this is necessary to have a reproducible enumeration Therefore we can not create devices or hotplug slots for any PCI device associated with a zPCI device before having discovered the function zero of the bus. The discovery and initialization of devices can be done at several points in the code: - On Events, serialized in a thread context - On initialization, in the kernel init thread context - When powering on the hotplug slot, in a user thread context The removal of devices and their parent bus may also be done on events or for devices when powering down the slot. To guarantee the existence of the bus and devices until they are no more needed we use kref in zPCI bus and introduce a reference count in the zPCI devices. In this patch the zPCI bus still only accept a device with a devfn 0. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-03-23 17:45:43 +08:00
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright IBM Corp. 2020
*
* Author(s):
* Pierre Morel <pmorel@linux.ibm.com>
*
*/
int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops);
void zpci_bus_device_unregister(struct zpci_dev *zdev);
int zpci_bus_init(void);
void zpci_release_device(struct kref *kref);
static inline void zpci_zdev_put(struct zpci_dev *zdev)
{
kref_put(&zdev->kref, zpci_release_device);
}
int zpci_alloc_domain(int domain);
void zpci_free_domain(int domain);
int zpci_setup_bus_resources(struct zpci_dev *zdev,
struct list_head *resources);
s390/pci: Handling multifunctions We allow multiple functions on a single bus. We suppress the ZPCI_DEVFN definition and replace its occurences with zpci->devfn. We verify the number of device during the registration. There can never be more domains in use than existing devices, so we do not need to verify the count of domain after having verified the count of devices. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-22 21:15:23 +08:00
static inline struct zpci_dev *get_zdev_by_bus(struct pci_bus *bus,
unsigned int devfn)
s390/pci: create zPCI bus The zPCI bus is in charge to handle common zPCI resources for zPCI devices. Creating the zPCI bus, the PCI bus, the zPCI devices and the PCI devices and hotplug slots done in a specific order: - PCI hotplug slot creation needs a PCI bus - PCI bus needs a PCI domain which is reported by the pci_domain_nr() when setting up the host bridge - PCI domain is set from the zPCI with devfn 0 this is necessary to have a reproducible enumeration Therefore we can not create devices or hotplug slots for any PCI device associated with a zPCI device before having discovered the function zero of the bus. The discovery and initialization of devices can be done at several points in the code: - On Events, serialized in a thread context - On initialization, in the kernel init thread context - When powering on the hotplug slot, in a user thread context The removal of devices and their parent bus may also be done on events or for devices when powering down the slot. To guarantee the existence of the bus and devices until they are no more needed we use kref in zPCI bus and introduce a reference count in the zPCI devices. In this patch the zPCI bus still only accept a device with a devfn 0. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-03-23 17:45:43 +08:00
{
struct zpci_bus *zbus = bus->sysdata;
s390/pci: Handling multifunctions We allow multiple functions on a single bus. We suppress the ZPCI_DEVFN definition and replace its occurences with zpci->devfn. We verify the number of device during the registration. There can never be more domains in use than existing devices, so we do not need to verify the count of domain after having verified the count of devices. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-22 21:15:23 +08:00
return (devfn >= ZPCI_FUNCTIONS_PER_BUS) ? NULL : zbus->function[devfn];
s390/pci: create zPCI bus The zPCI bus is in charge to handle common zPCI resources for zPCI devices. Creating the zPCI bus, the PCI bus, the zPCI devices and the PCI devices and hotplug slots done in a specific order: - PCI hotplug slot creation needs a PCI bus - PCI bus needs a PCI domain which is reported by the pci_domain_nr() when setting up the host bridge - PCI domain is set from the zPCI with devfn 0 this is necessary to have a reproducible enumeration Therefore we can not create devices or hotplug slots for any PCI device associated with a zPCI device before having discovered the function zero of the bus. The discovery and initialization of devices can be done at several points in the code: - On Events, serialized in a thread context - On initialization, in the kernel init thread context - When powering on the hotplug slot, in a user thread context The removal of devices and their parent bus may also be done on events or for devices when powering down the slot. To guarantee the existence of the bus and devices until they are no more needed we use kref in zPCI bus and introduce a reference count in the zPCI devices. In this patch the zPCI bus still only accept a device with a devfn 0. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-03-23 17:45:43 +08:00
}
s390/pci: fix PF/VF linking on hot plug Currently there are four places in which a PCI function is scanned and made available to drivers: 1. In pci_scan_root_bus() as part of the initial zbus creation. 2. In zpci_bus_add_devices() when registering a device in configured state on a zbus that has already been scanned. 3. When a function is already known to zPCI (in reserved/standby state) and configuration is triggered through firmware by PEC 0x301. 4. When a device is already known to zPCI (in standby/reserved state) and configuration is triggered from within Linux using enable_slot(). The PF/VF linking step and setting of pdev->is_virtfn introduced with commit e5794cf1a270 ("s390/pci: create links between PFs and VFs") was only triggered for the second case, which is where VFs created through sriov_numvfs usually land. However unlike some other platforms but like POWER VFs can be individually enabled/disabled through /sys/bus/pci/slots. Fix this by doing VF setup as part of pcibios_bus_add_device() which is called in all of the above cases. Finally to remove the PF/VF links call the common code pci_iov_remove_virtfn() function to remove linked VFs. This takes care of the necessary sysfs cleanup. Fixes: e5794cf1a270 ("s390/pci: create links between PFs and VFs") Cc: <stable@vger.kernel.org> # 5.8: 2f0230b2f2d5: s390/pci: re-introduce zpci_remove_device() Cc: <stable@vger.kernel.org> # 5.8 Acked-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-08-03 23:58:10 +08:00
#ifdef CONFIG_PCI_IOV
static inline void zpci_remove_virtfn(struct pci_dev *pdev, int vfn)
{
pci_lock_rescan_remove();
/* Linux' vfid's start at 0 vfn at 1 */
pci_iov_remove_virtfn(pdev->physfn, vfn - 1);
pci_unlock_rescan_remove();
}
#else /* CONFIG_PCI_IOV */
static inline void zpci_remove_virtfn(struct pci_dev *pdev, int vfn) {}
#endif /* CONFIG_PCI_IOV */