1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright IBM Corp. 2020
6 * Pierre Morel <pmorel@linux.ibm.com>
10 #define KMSG_COMPONENT "zpci"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13 #include <linux/kernel.h>
14 #include <linux/slab.h>
15 #include <linux/err.h>
16 #include <linux/export.h>
17 #include <linux/delay.h>
18 #include <linux/seq_file.h>
19 #include <linux/jump_label.h>
20 #include <linux/pci.h>
21 #include <linux/printk.h>
23 #include <asm/pci_clp.h>
24 #include <asm/pci_dma.h>
29 static LIST_HEAD(zbus_list);
30 static DEFINE_SPINLOCK(zbus_list_lock);
31 static int zpci_nb_devices;
34 * @zbus: the zbus holding the zdevices
35 * @ops: the pci operations
37 * The domain number must be set before pci_scan_root_bus is called.
38 * This function can be called once the domain is known, hence
39 * when the function_0 is dicovered.
41 static int zpci_bus_scan(struct zpci_bus *zbus, int domain, struct pci_ops *ops)
46 rc = zpci_alloc_domain(domain);
51 bus = pci_scan_root_bus(NULL, ZPCI_BUS_NR, ops, zbus, &zbus->resources);
53 zpci_free_domain(zbus->domain_nr);
58 pci_bus_add_devices(bus);
62 static void zpci_bus_release(struct kref *kref)
64 struct zpci_bus *zbus = container_of(kref, struct zpci_bus, kref);
67 pci_lock_rescan_remove();
68 pci_stop_root_bus(zbus->bus);
70 zpci_free_domain(zbus->domain_nr);
71 pci_free_resource_list(&zbus->resources);
73 pci_remove_root_bus(zbus->bus);
74 pci_unlock_rescan_remove();
77 spin_lock(&zbus_list_lock);
78 list_del(&zbus->bus_next);
79 spin_unlock(&zbus_list_lock);
83 static void zpci_bus_put(struct zpci_bus *zbus)
85 kref_put(&zbus->kref, zpci_bus_release);
88 static struct zpci_bus *zpci_bus_get(int pchid)
90 struct zpci_bus *zbus;
92 spin_lock(&zbus_list_lock);
93 list_for_each_entry(zbus, &zbus_list, bus_next) {
94 if (pchid == zbus->pchid) {
95 kref_get(&zbus->kref);
101 spin_unlock(&zbus_list_lock);
105 static struct zpci_bus *zpci_bus_alloc(int pchid)
107 struct zpci_bus *zbus;
109 zbus = kzalloc(sizeof(*zbus), GFP_KERNEL);
114 INIT_LIST_HEAD(&zbus->bus_next);
115 spin_lock(&zbus_list_lock);
116 list_add_tail(&zbus->bus_next, &zbus_list);
117 spin_unlock(&zbus_list_lock);
119 kref_init(&zbus->kref);
120 INIT_LIST_HEAD(&zbus->resources);
122 zbus->bus_resource.start = 0;
123 zbus->bus_resource.end = ZPCI_BUS_NR;
124 zbus->bus_resource.flags = IORESOURCE_BUS;
125 pci_add_resource(&zbus->resources, &zbus->bus_resource);
130 void pcibios_bus_add_device(struct pci_dev *pdev)
132 struct zpci_dev *zdev = to_zpci(pdev);
135 * With pdev->no_vf_scan the common PCI probing code does not
136 * perform PF/VF linking.
139 zpci_iov_setup_virtfn(zdev->zbus, pdev, zdev->vfn);
140 pdev->no_command_memory = 1;
144 static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev)
147 struct resource_entry *window, *n;
148 struct resource *res;
149 struct pci_dev *pdev;
156 pdev = pci_get_slot(bus, zdev->devfn);
158 /* Device is already known. */
163 rc = zpci_init_slot(zdev);
166 zdev->has_hp_slot = 1;
168 resource_list_for_each_entry_safe(window, n, &zbus->resources) {
170 pci_bus_add_resource(bus, res, 0);
173 pdev = pci_scan_single_device(bus, zdev->devfn);
175 pci_bus_add_device(pdev);
180 static void zpci_bus_add_devices(struct zpci_bus *zbus)
184 for (i = 1; i < ZPCI_FUNCTIONS_PER_BUS; i++)
185 if (zbus->function[i])
186 zpci_bus_add_device(zbus, zbus->function[i]);
188 pci_lock_rescan_remove();
189 pci_bus_add_devices(zbus->bus);
190 pci_unlock_rescan_remove();
193 int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops)
195 struct zpci_bus *zbus = NULL;
198 if (zpci_nb_devices == ZPCI_NR_DEVICES) {
199 pr_warn("Adding PCI function %08x failed because the configured limit of %d is reached\n",
200 zdev->fid, ZPCI_NR_DEVICES);
205 if (zdev->devfn >= ZPCI_FUNCTIONS_PER_BUS)
208 if (!s390_pci_no_rid && zdev->rid_available)
209 zbus = zpci_bus_get(zdev->pchid);
212 zbus = zpci_bus_alloc(zdev->pchid);
218 if (zbus->function[zdev->devfn]) {
219 pr_err("devfn %04x is already assigned\n", zdev->devfn);
220 goto error; /* rc already set */
222 zbus->function[zdev->devfn] = zdev;
224 zpci_setup_bus_resources(zdev, &zbus->resources);
227 if (!zbus->multifunction) {
228 WARN_ONCE(1, "zbus is not multifunction\n");
231 if (!zdev->rid_available) {
232 WARN_ONCE(1, "rid_available not set for multifunction\n");
235 rc = zpci_bus_add_device(zbus, zdev);
238 } else if (zdev->devfn == 0) {
239 if (zbus->multifunction && !zdev->rid_available) {
240 WARN_ONCE(1, "rid_available not set on function 0 for multifunction\n");
243 rc = zpci_bus_scan(zbus, (u16)zdev->uid, ops);
246 zpci_bus_add_devices(zbus);
247 rc = zpci_init_slot(zdev);
250 zdev->has_hp_slot = 1;
251 zbus->multifunction = zdev->rid_available;
252 zbus->max_bus_speed = zdev->max_bus_speed;
254 zbus->multifunction = 1;
261 zbus->function[zdev->devfn] = NULL;
263 pr_err("Adding PCI function %08x failed\n", zdev->fid);
268 void zpci_bus_device_unregister(struct zpci_dev *zdev)
270 struct zpci_bus *zbus = zdev->zbus;
273 zbus->function[zdev->devfn] = NULL;