diff options
Diffstat (limited to 'arch/s390/pci/pci_bus.c')
| -rw-r--r-- | arch/s390/pci/pci_bus.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/arch/s390/pci/pci_bus.c b/arch/s390/pci/pci_bus.c new file mode 100644 index 000000000..755b46f4c --- /dev/null +++ b/arch/s390/pci/pci_bus.c @@ -0,0 +1,275 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright IBM Corp. 2020 + * + * Author(s): + * Pierre Morel <pmorel@linux.ibm.com> + * + */ + +#define KMSG_COMPONENT "zpci" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/delay.h> +#include <linux/seq_file.h> +#include <linux/jump_label.h> +#include <linux/pci.h> +#include <linux/printk.h> + +#include <asm/pci_clp.h> +#include <asm/pci_dma.h> + +#include "pci_bus.h" +#include "pci_iov.h" + +static LIST_HEAD(zbus_list); +static DEFINE_SPINLOCK(zbus_list_lock); +static int zpci_nb_devices; + +/* zpci_bus_scan + * @zbus: the zbus holding the zdevices + * @ops: the pci operations + * + * The domain number must be set before pci_scan_root_bus is called. + * This function can be called once the domain is known, hence + * when the function_0 is dicovered. + */ +static int zpci_bus_scan(struct zpci_bus *zbus, int domain, struct pci_ops *ops) +{ + struct pci_bus *bus; + int rc; + + rc = zpci_alloc_domain(domain); + if (rc < 0) + return rc; + zbus->domain_nr = rc; + + bus = pci_scan_root_bus(NULL, ZPCI_BUS_NR, ops, zbus, &zbus->resources); + if (!bus) { + zpci_free_domain(zbus->domain_nr); + return -EFAULT; + } + + zbus->bus = bus; + pci_bus_add_devices(bus); + return 0; +} + +static void zpci_bus_release(struct kref *kref) +{ + struct zpci_bus *zbus = container_of(kref, struct zpci_bus, kref); + + if (zbus->bus) { + pci_lock_rescan_remove(); + pci_stop_root_bus(zbus->bus); + + zpci_free_domain(zbus->domain_nr); + pci_free_resource_list(&zbus->resources); + + pci_remove_root_bus(zbus->bus); + pci_unlock_rescan_remove(); + } + + spin_lock(&zbus_list_lock); + list_del(&zbus->bus_next); + spin_unlock(&zbus_list_lock); + kfree(zbus); +} + +static void zpci_bus_put(struct zpci_bus *zbus) +{ + kref_put(&zbus->kref, zpci_bus_release); +} + +static struct zpci_bus *zpci_bus_get(int pchid) +{ + struct zpci_bus *zbus; + + spin_lock(&zbus_list_lock); + list_for_each_entry(zbus, &zbus_list, bus_next) { + if (pchid == zbus->pchid) { + kref_get(&zbus->kref); + goto out_unlock; + } + } + zbus = NULL; +out_unlock: + spin_unlock(&zbus_list_lock); + return zbus; +} + +static struct zpci_bus *zpci_bus_alloc(int pchid) +{ + struct zpci_bus *zbus; + + zbus = kzalloc(sizeof(*zbus), GFP_KERNEL); + if (!zbus) + return NULL; + + zbus->pchid = pchid; + INIT_LIST_HEAD(&zbus->bus_next); + spin_lock(&zbus_list_lock); + list_add_tail(&zbus->bus_next, &zbus_list); + spin_unlock(&zbus_list_lock); + + kref_init(&zbus->kref); + INIT_LIST_HEAD(&zbus->resources); + + zbus->bus_resource.start = 0; + zbus->bus_resource.end = ZPCI_BUS_NR; + zbus->bus_resource.flags = IORESOURCE_BUS; + pci_add_resource(&zbus->resources, &zbus->bus_resource); + + return zbus; +} + +void pcibios_bus_add_device(struct pci_dev *pdev) +{ + struct zpci_dev *zdev = to_zpci(pdev); + + /* + * With pdev->no_vf_scan the common PCI probing code does not + * perform PF/VF linking. + */ + if (zdev->vfn) { + zpci_iov_setup_virtfn(zdev->zbus, pdev, zdev->vfn); + pdev->no_command_memory = 1; + } +} + +static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev) +{ + struct pci_bus *bus; + struct resource_entry *window, *n; + struct resource *res; + struct pci_dev *pdev; + int rc; + + bus = zbus->bus; + if (!bus) + return -EINVAL; + + pdev = pci_get_slot(bus, zdev->devfn); + if (pdev) { + /* Device is already known. */ + pci_dev_put(pdev); + return 0; + } + + rc = zpci_init_slot(zdev); + if (rc) + return rc; + zdev->has_hp_slot = 1; + + resource_list_for_each_entry_safe(window, n, &zbus->resources) { + res = window->res; + pci_bus_add_resource(bus, res, 0); + } + + pdev = pci_scan_single_device(bus, zdev->devfn); + if (pdev) + pci_bus_add_device(pdev); + + return 0; +} + +static void zpci_bus_add_devices(struct zpci_bus *zbus) +{ + int i; + + for (i = 1; i < ZPCI_FUNCTIONS_PER_BUS; i++) + if (zbus->function[i]) + zpci_bus_add_device(zbus, zbus->function[i]); + + pci_lock_rescan_remove(); + pci_bus_add_devices(zbus->bus); + pci_unlock_rescan_remove(); +} + +int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops) +{ + struct zpci_bus *zbus = NULL; + int rc = -EBADF; + + if (zpci_nb_devices == ZPCI_NR_DEVICES) { + pr_warn("Adding PCI function %08x failed because the configured limit of %d is reached\n", + zdev->fid, ZPCI_NR_DEVICES); + return -ENOSPC; + } + zpci_nb_devices++; + + if (zdev->devfn >= ZPCI_FUNCTIONS_PER_BUS) + return -EINVAL; + + if (!s390_pci_no_rid && zdev->rid_available) + zbus = zpci_bus_get(zdev->pchid); + + if (!zbus) { + zbus = zpci_bus_alloc(zdev->pchid); + if (!zbus) + return -ENOMEM; + } + + zdev->zbus = zbus; + if (zbus->function[zdev->devfn]) { + pr_err("devfn %04x is already assigned\n", zdev->devfn); + goto error; /* rc already set */ + } + zbus->function[zdev->devfn] = zdev; + + zpci_setup_bus_resources(zdev, &zbus->resources); + + if (zbus->bus) { + if (!zbus->multifunction) { + WARN_ONCE(1, "zbus is not multifunction\n"); + goto error_bus; + } + if (!zdev->rid_available) { + WARN_ONCE(1, "rid_available not set for multifunction\n"); + goto error_bus; + } + rc = zpci_bus_add_device(zbus, zdev); + if (rc) + goto error_bus; + } else if (zdev->devfn == 0) { + if (zbus->multifunction && !zdev->rid_available) { + WARN_ONCE(1, "rid_available not set on function 0 for multifunction\n"); + goto error_bus; + } + rc = zpci_bus_scan(zbus, (u16)zdev->uid, ops); + if (rc) + goto error_bus; + zpci_bus_add_devices(zbus); + rc = zpci_init_slot(zdev); + if (rc) + goto error_bus; + zdev->has_hp_slot = 1; + zbus->multifunction = zdev->rid_available; + zbus->max_bus_speed = zdev->max_bus_speed; + } else { + zbus->multifunction = 1; + } + + return 0; + +error_bus: + zpci_nb_devices--; + zbus->function[zdev->devfn] = NULL; +error: + pr_err("Adding PCI function %08x failed\n", zdev->fid); + zpci_bus_put(zbus); + return rc; +} + +void zpci_bus_device_unregister(struct zpci_dev *zdev) +{ + struct zpci_bus *zbus = zdev->zbus; + + zpci_nb_devices--; + zbus->function[zdev->devfn] = NULL; + zpci_bus_put(zbus); +} |