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_MUTEX(zbus_list_lock);
31 static int zpci_nb_devices;
33 /* zpci_bus_prepare_device - Prepare a zPCI function for scanning
34 * @zdev: the zPCI function to be prepared
36 * The PCI resources for the function are set up and added to its zbus and the
37 * function is enabled. The function must be added to a zbus which must have
38 * a PCI bus created. If an error occurs the zPCI function is not enabled.
40 * Return: 0 on success, an error code otherwise
42 static int zpci_bus_prepare_device(struct zpci_dev *zdev)
46 if (!zdev_enabled(zdev)) {
47 rc = zpci_enable_device(zdev);
50 rc = zpci_dma_init_device(zdev);
52 zpci_disable_device(zdev);
57 if (!zdev->has_resources) {
58 zpci_setup_bus_resources(zdev);
59 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
60 if (zdev->bars[i].res)
61 pci_bus_add_resource(zdev->zbus->bus, zdev->bars[i].res, 0);
68 /* zpci_bus_scan_device - Scan a single device adding it to the PCI core
69 * @zdev: the zdev to be scanned
71 * Scans the PCI function making it available to the common PCI code.
73 * Return: 0 on success, an error value otherwise
75 int zpci_bus_scan_device(struct zpci_dev *zdev)
80 rc = zpci_bus_prepare_device(zdev);
84 pdev = pci_scan_single_device(zdev->zbus->bus, zdev->devfn);
88 pci_bus_add_device(pdev);
89 pci_lock_rescan_remove();
90 pci_bus_add_devices(zdev->zbus->bus);
91 pci_unlock_rescan_remove();
96 /* zpci_bus_remove_device - Removes the given zdev from the PCI core
97 * @zdev: the zdev to be removed from the PCI core
98 * @set_error: if true the device's error state is set to permanent failure
100 * Sets a zPCI device to a configured but offline state; the zPCI
101 * device is still accessible through its hotplug slot and the zPCI
102 * API but is removed from the common code PCI bus, making it
103 * no longer available to drivers.
105 void zpci_bus_remove_device(struct zpci_dev *zdev, bool set_error)
107 struct zpci_bus *zbus = zdev->zbus;
108 struct pci_dev *pdev;
110 if (!zdev->zbus->bus)
113 pdev = pci_get_slot(zbus->bus, zdev->devfn);
116 pdev->error_state = pci_channel_io_perm_failure;
117 if (pdev->is_virtfn) {
118 zpci_iov_remove_virtfn(pdev, zdev->vfn);
119 /* balance pci_get_slot */
123 pci_stop_and_remove_bus_device_locked(pdev);
124 /* balance pci_get_slot */
129 /* zpci_bus_scan_bus - Scan all configured zPCI functions on the bus
130 * @zbus: the zbus to be scanned
132 * Enables and scans all PCI functions on the bus making them available to the
133 * common PCI code. If there is no function 0 on the zbus nothing is scanned. If
134 * a function does not have a slot yet because it was added to the zbus before
135 * function 0 the slot is created. If a PCI function fails to be initialized
136 * an error will be returned but attempts will still be made for all other
137 * functions on the bus.
139 * Return: 0 on success, an error value otherwise
141 int zpci_bus_scan_bus(struct zpci_bus *zbus)
143 struct zpci_dev *zdev;
144 int devfn, rc, ret = 0;
146 for (devfn = 0; devfn < ZPCI_FUNCTIONS_PER_BUS; devfn++) {
147 zdev = zbus->function[devfn];
148 if (zdev && zdev->state == ZPCI_FN_STATE_CONFIGURED) {
149 rc = zpci_bus_prepare_device(zdev);
155 pci_lock_rescan_remove();
156 pci_scan_child_bus(zbus->bus);
157 pci_bus_add_devices(zbus->bus);
158 pci_unlock_rescan_remove();
163 /* zpci_bus_scan_busses - Scan all registered busses
165 * Scan all available zbusses
168 void zpci_bus_scan_busses(void)
170 struct zpci_bus *zbus = NULL;
172 mutex_lock(&zbus_list_lock);
173 list_for_each_entry(zbus, &zbus_list, bus_next) {
174 zpci_bus_scan_bus(zbus);
177 mutex_unlock(&zbus_list_lock);
180 /* zpci_bus_create_pci_bus - Create the PCI bus associated with this zbus
181 * @zbus: the zbus holding the zdevices
182 * @fr: PCI root function that will determine the bus's domain, and bus speeed
183 * @ops: the pci operations
185 * The PCI function @fr determines the domain (its UID), multifunction property
186 * and maximum bus speed of the entire bus.
188 * Return: 0 on success, an error code otherwise
190 static int zpci_bus_create_pci_bus(struct zpci_bus *zbus, struct zpci_dev *fr, struct pci_ops *ops)
195 domain = zpci_alloc_domain((u16)fr->uid);
199 zbus->domain_nr = domain;
200 zbus->multifunction = fr->rid_available;
201 zbus->max_bus_speed = fr->max_bus_speed;
204 * Note that the zbus->resources are taken over and zbus->resources
205 * is empty after a successful call
207 bus = pci_create_root_bus(NULL, ZPCI_BUS_NR, ops, zbus, &zbus->resources);
209 zpci_free_domain(zbus->domain_nr);
214 pci_bus_add_devices(bus);
219 static void zpci_bus_release(struct kref *kref)
221 struct zpci_bus *zbus = container_of(kref, struct zpci_bus, kref);
224 pci_lock_rescan_remove();
225 pci_stop_root_bus(zbus->bus);
227 zpci_free_domain(zbus->domain_nr);
228 pci_free_resource_list(&zbus->resources);
230 pci_remove_root_bus(zbus->bus);
231 pci_unlock_rescan_remove();
234 mutex_lock(&zbus_list_lock);
235 list_del(&zbus->bus_next);
236 mutex_unlock(&zbus_list_lock);
240 static void zpci_bus_put(struct zpci_bus *zbus)
242 kref_put(&zbus->kref, zpci_bus_release);
245 static struct zpci_bus *zpci_bus_get(int pchid)
247 struct zpci_bus *zbus;
249 mutex_lock(&zbus_list_lock);
250 list_for_each_entry(zbus, &zbus_list, bus_next) {
251 if (pchid == zbus->pchid) {
252 kref_get(&zbus->kref);
258 mutex_unlock(&zbus_list_lock);
262 static struct zpci_bus *zpci_bus_alloc(int pchid)
264 struct zpci_bus *zbus;
266 zbus = kzalloc(sizeof(*zbus), GFP_KERNEL);
271 INIT_LIST_HEAD(&zbus->bus_next);
272 mutex_lock(&zbus_list_lock);
273 list_add_tail(&zbus->bus_next, &zbus_list);
274 mutex_unlock(&zbus_list_lock);
276 kref_init(&zbus->kref);
277 INIT_LIST_HEAD(&zbus->resources);
279 zbus->bus_resource.start = 0;
280 zbus->bus_resource.end = ZPCI_BUS_NR;
281 zbus->bus_resource.flags = IORESOURCE_BUS;
282 pci_add_resource(&zbus->resources, &zbus->bus_resource);
287 void pcibios_bus_add_device(struct pci_dev *pdev)
289 struct zpci_dev *zdev = to_zpci(pdev);
292 * With pdev->no_vf_scan the common PCI probing code does not
293 * perform PF/VF linking.
296 zpci_iov_setup_virtfn(zdev->zbus, pdev, zdev->vfn);
297 pdev->no_command_memory = 1;
301 static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev)
305 if (zbus->function[zdev->devfn]) {
306 pr_err("devfn %04x is already assigned\n", zdev->devfn);
311 zbus->function[zdev->devfn] = zdev;
314 if (zbus->multifunction && !zdev->rid_available) {
315 WARN_ONCE(1, "rid_available not set for multifunction\n");
318 rc = zpci_init_slot(zdev);
321 zdev->has_hp_slot = 1;
326 zbus->function[zdev->devfn] = NULL;
332 int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops)
334 struct zpci_bus *zbus = NULL;
337 if (zpci_nb_devices == ZPCI_NR_DEVICES) {
338 pr_warn("Adding PCI function %08x failed because the configured limit of %d is reached\n",
339 zdev->fid, ZPCI_NR_DEVICES);
343 if (zdev->devfn >= ZPCI_FUNCTIONS_PER_BUS)
346 if (!s390_pci_no_rid && zdev->rid_available)
347 zbus = zpci_bus_get(zdev->pchid);
350 zbus = zpci_bus_alloc(zdev->pchid);
356 /* The UID of the first PCI function registered with a zpci_bus
357 * is used as the domain number for that bus. Currently there
358 * is exactly one zpci_bus per domain.
360 rc = zpci_bus_create_pci_bus(zbus, zdev, ops);
365 rc = zpci_bus_add_device(zbus, zdev);
372 pr_err("Adding PCI function %08x failed\n", zdev->fid);
377 void zpci_bus_device_unregister(struct zpci_dev *zdev)
379 struct zpci_bus *zbus = zdev->zbus;
382 zbus->function[zdev->devfn] = NULL;