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>
28 static LIST_HEAD(zbus_list);
29 static DEFINE_SPINLOCK(zbus_list_lock);
30 static int zpci_nb_devices;
33 * @zbus: the zbus holding the zdevices
34 * @ops: the pci operations
36 * The domain number must be set before pci_scan_root_bus is called.
37 * This function can be called once the domain is known, hence
38 * when the function_0 is dicovered.
40 static int zpci_bus_scan(struct zpci_bus *zbus, int domain, struct pci_ops *ops)
45 rc = zpci_alloc_domain(domain);
50 bus = pci_scan_root_bus(NULL, ZPCI_BUS_NR, ops, zbus, &zbus->resources);
52 zpci_free_domain(zbus->domain_nr);
57 pci_bus_add_devices(bus);
61 static void zpci_bus_release(struct kref *kref)
63 struct zpci_bus *zbus = container_of(kref, struct zpci_bus, kref);
66 pci_lock_rescan_remove();
67 pci_stop_root_bus(zbus->bus);
69 zpci_free_domain(zbus->domain_nr);
70 pci_free_resource_list(&zbus->resources);
72 pci_remove_root_bus(zbus->bus);
73 pci_unlock_rescan_remove();
76 spin_lock(&zbus_list_lock);
77 list_del(&zbus->bus_next);
78 spin_unlock(&zbus_list_lock);
82 static void zpci_bus_put(struct zpci_bus *zbus)
84 kref_put(&zbus->kref, zpci_bus_release);
87 static struct zpci_bus *zpci_bus_get(int pchid)
89 struct zpci_bus *zbus;
91 spin_lock(&zbus_list_lock);
92 list_for_each_entry(zbus, &zbus_list, bus_next) {
93 if (pchid == zbus->pchid) {
94 kref_get(&zbus->kref);
100 spin_unlock(&zbus_list_lock);
104 static struct zpci_bus *zpci_bus_alloc(int pchid)
106 struct zpci_bus *zbus;
108 zbus = kzalloc(sizeof(*zbus), GFP_KERNEL);
113 INIT_LIST_HEAD(&zbus->bus_next);
114 spin_lock(&zbus_list_lock);
115 list_add_tail(&zbus->bus_next, &zbus_list);
116 spin_unlock(&zbus_list_lock);
118 kref_init(&zbus->kref);
119 INIT_LIST_HEAD(&zbus->resources);
121 zbus->bus_resource.start = 0;
122 zbus->bus_resource.end = ZPCI_BUS_NR;
123 zbus->bus_resource.flags = IORESOURCE_BUS;
124 pci_add_resource(&zbus->resources, &zbus->bus_resource);
129 #ifdef CONFIG_PCI_IOV
130 static int zpci_bus_link_virtfn(struct pci_dev *pdev,
131 struct pci_dev *virtfn, int vfid)
135 rc = pci_iov_sysfs_link(pdev, virtfn, vfid);
139 virtfn->is_virtfn = 1;
140 virtfn->multifunction = 0;
141 virtfn->physfn = pci_dev_get(pdev);
146 static int zpci_bus_setup_virtfn(struct zpci_bus *zbus,
147 struct pci_dev *virtfn, int vfn)
150 struct zpci_dev *zdev;
151 struct pci_dev *pdev;
152 int vfid = vfn - 1; /* Linux' vfid's start at 0 vfn at 1*/
155 if (!zbus->multifunction)
158 /* If the parent PF for the given VF is also configured in the
159 * instance, it must be on the same zbus.
160 * We can then identify the parent PF by checking what
161 * devfn the VF would have if it belonged to that PF using the PF's
162 * stride and offset. Only if this candidate devfn matches the
163 * actual devfn will we link both functions.
165 for (i = 0; i < ZPCI_FUNCTIONS_PER_BUS; i++) {
166 zdev = zbus->function[i];
167 if (zdev && zdev->is_physfn) {
168 pdev = pci_get_slot(zbus->bus, zdev->devfn);
171 cand_devfn = pci_iov_virtfn_devfn(pdev, vfid);
172 if (cand_devfn == virtfn->devfn) {
173 rc = zpci_bus_link_virtfn(pdev, virtfn, vfid);
174 /* balance pci_get_slot() */
178 /* balance pci_get_slot() */
185 static inline int zpci_bus_setup_virtfn(struct zpci_bus *zbus,
186 struct pci_dev *virtfn, int vfn)
192 void pcibios_bus_add_device(struct pci_dev *pdev)
194 struct zpci_dev *zdev = to_zpci(pdev);
197 * With pdev->no_vf_scan the common PCI probing code does not
198 * perform PF/VF linking.
201 zpci_bus_setup_virtfn(zdev->zbus, pdev, zdev->vfn);
202 pdev->no_command_memory = 1;
206 static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev)
209 struct resource_entry *window, *n;
210 struct resource *res;
211 struct pci_dev *pdev;
218 pdev = pci_get_slot(bus, zdev->devfn);
220 /* Device is already known. */
225 rc = zpci_init_slot(zdev);
228 zdev->has_hp_slot = 1;
230 resource_list_for_each_entry_safe(window, n, &zbus->resources) {
232 pci_bus_add_resource(bus, res, 0);
235 pdev = pci_scan_single_device(bus, zdev->devfn);
237 pci_bus_add_device(pdev);
242 static void zpci_bus_add_devices(struct zpci_bus *zbus)
246 for (i = 1; i < ZPCI_FUNCTIONS_PER_BUS; i++)
247 if (zbus->function[i])
248 zpci_bus_add_device(zbus, zbus->function[i]);
250 pci_lock_rescan_remove();
251 pci_bus_add_devices(zbus->bus);
252 pci_unlock_rescan_remove();
255 int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops)
257 struct zpci_bus *zbus = NULL;
260 if (zpci_nb_devices == ZPCI_NR_DEVICES) {
261 pr_warn("Adding PCI function %08x failed because the configured limit of %d is reached\n",
262 zdev->fid, ZPCI_NR_DEVICES);
267 if (zdev->devfn >= ZPCI_FUNCTIONS_PER_BUS)
270 if (!s390_pci_no_rid && zdev->rid_available)
271 zbus = zpci_bus_get(zdev->pchid);
274 zbus = zpci_bus_alloc(zdev->pchid);
280 if (zbus->function[zdev->devfn]) {
281 pr_err("devfn %04x is already assigned\n", zdev->devfn);
282 goto error; /* rc already set */
284 zbus->function[zdev->devfn] = zdev;
286 zpci_setup_bus_resources(zdev, &zbus->resources);
289 if (!zbus->multifunction) {
290 WARN_ONCE(1, "zbus is not multifunction\n");
293 if (!zdev->rid_available) {
294 WARN_ONCE(1, "rid_available not set for multifunction\n");
297 rc = zpci_bus_add_device(zbus, zdev);
300 } else if (zdev->devfn == 0) {
301 if (zbus->multifunction && !zdev->rid_available) {
302 WARN_ONCE(1, "rid_available not set on function 0 for multifunction\n");
305 rc = zpci_bus_scan(zbus, (u16)zdev->uid, ops);
308 zpci_bus_add_devices(zbus);
309 rc = zpci_init_slot(zdev);
312 zdev->has_hp_slot = 1;
313 zbus->multifunction = zdev->rid_available;
314 zbus->max_bus_speed = zdev->max_bus_speed;
316 zbus->multifunction = 1;
323 zbus->function[zdev->devfn] = NULL;
325 pr_err("Adding PCI function %08x failed\n", zdev->fid);
330 void zpci_bus_device_unregister(struct zpci_dev *zdev)
332 struct zpci_bus *zbus = zdev->zbus;
335 zbus->function[zdev->devfn] = NULL;