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)
44 struct resource_entry *window, *n;
48 if (!zdev_enabled(zdev)) {
49 rc = zpci_enable_device(zdev);
54 if (!zdev->has_resources) {
55 zpci_setup_bus_resources(zdev, &zdev->zbus->resources);
56 resource_list_for_each_entry_safe(window, n, &zdev->zbus->resources) {
58 pci_bus_add_resource(zdev->zbus->bus, res, 0);
65 /* zpci_bus_scan_device - Scan a single device adding it to the PCI core
66 * @zdev: the zdev to be scanned
68 * Scans the PCI function making it available to the common PCI code.
70 * Return: 0 on success, an error value otherwise
72 int zpci_bus_scan_device(struct zpci_dev *zdev)
77 rc = zpci_bus_prepare_device(zdev);
81 pdev = pci_scan_single_device(zdev->zbus->bus, zdev->devfn);
85 pci_bus_add_device(pdev);
86 pci_lock_rescan_remove();
87 pci_bus_add_devices(zdev->zbus->bus);
88 pci_unlock_rescan_remove();
93 /* zpci_bus_remove_device - Removes the given zdev from the PCI core
94 * @zdev: the zdev to be removed from the PCI core
95 * @set_error: if true the device's error state is set to permanent failure
97 * Sets a zPCI device to a configured but offline state; the zPCI
98 * device is still accessible through its hotplug slot and the zPCI
99 * API but is removed from the common code PCI bus, making it
100 * no longer available to drivers.
102 void zpci_bus_remove_device(struct zpci_dev *zdev, bool set_error)
104 struct zpci_bus *zbus = zdev->zbus;
105 struct pci_dev *pdev;
107 if (!zdev->zbus->bus)
110 pdev = pci_get_slot(zbus->bus, zdev->devfn);
113 pdev->error_state = pci_channel_io_perm_failure;
114 if (pdev->is_virtfn) {
115 zpci_iov_remove_virtfn(pdev, zdev->vfn);
116 /* balance pci_get_slot */
120 pci_stop_and_remove_bus_device_locked(pdev);
121 /* balance pci_get_slot */
126 /* zpci_bus_scan_bus - Scan all configured zPCI functions on the bus
127 * @zbus: the zbus to be scanned
129 * Enables and scans all PCI functions on the bus making them available to the
130 * common PCI code. If there is no function 0 on the zbus nothing is scanned. If
131 * a function does not have a slot yet because it was added to the zbus before
132 * function 0 the slot is created. If a PCI function fails to be initialized
133 * an error will be returned but attempts will still be made for all other
134 * functions on the bus.
136 * Return: 0 on success, an error value otherwise
138 int zpci_bus_scan_bus(struct zpci_bus *zbus)
140 struct zpci_dev *zdev;
141 int devfn, rc, ret = 0;
143 if (!zbus->function[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 * @f0: function 0 of the bus
183 * @ops: the pci operations
185 * Function zero is taken as a parameter as this is used to determine the
186 * domain, multifunction property 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 *f0, struct pci_ops *ops)
195 domain = zpci_alloc_domain((u16)f0->uid);
199 zbus->domain_nr = domain;
200 zbus->multifunction = f0->rid_available;
201 zbus->max_bus_speed = f0->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 /* zpci_bus_create_hotplug_slots - Add hotplug slot(s) for device added to bus
302 * @zdev: the zPCI device that was newly added
304 * Add the hotplug slot(s) for the newly added PCI function. Normally this is
305 * simply the slot for the function itself. If however we are adding the
306 * function 0 on a zbus, it might be that we already registered functions on
307 * that zbus but could not create their hotplug slots yet so add those now too.
309 * Return: 0 on success, an error code otherwise
311 static int zpci_bus_create_hotplug_slots(struct zpci_dev *zdev)
313 struct zpci_bus *zbus = zdev->zbus;
316 rc = zpci_init_slot(zdev);
319 zdev->has_hp_slot = 1;
321 if (zdev->devfn == 0 && zbus->multifunction) {
322 /* Now that function 0 is there we can finally create the
323 * hotplug slots for those functions with devfn != 0 that have
324 * been parked in zbus->function[] waiting for us to be able to
325 * create the PCI bus.
327 for (devfn = 1; devfn < ZPCI_FUNCTIONS_PER_BUS; devfn++) {
328 zdev = zbus->function[devfn];
329 if (zdev && !zdev->has_hp_slot) {
330 rc = zpci_init_slot(zdev);
333 zdev->has_hp_slot = 1;
342 static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev)
347 if (zbus->function[zdev->devfn]) {
348 pr_err("devfn %04x is already assigned\n", zdev->devfn);
351 zbus->function[zdev->devfn] = zdev;
355 if (zbus->multifunction && !zdev->rid_available) {
356 WARN_ONCE(1, "rid_available not set for multifunction\n");
360 zpci_bus_create_hotplug_slots(zdev);
362 /* Hotplug slot will be created once function 0 appears */
363 zbus->multifunction = 1;
369 zbus->function[zdev->devfn] = NULL;
374 int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops)
376 struct zpci_bus *zbus = NULL;
379 if (zpci_nb_devices == ZPCI_NR_DEVICES) {
380 pr_warn("Adding PCI function %08x failed because the configured limit of %d is reached\n",
381 zdev->fid, ZPCI_NR_DEVICES);
385 if (zdev->devfn >= ZPCI_FUNCTIONS_PER_BUS)
388 if (!s390_pci_no_rid && zdev->rid_available)
389 zbus = zpci_bus_get(zdev->pchid);
392 zbus = zpci_bus_alloc(zdev->pchid);
397 if (zdev->devfn == 0) {
398 rc = zpci_bus_create_pci_bus(zbus, zdev, ops);
403 rc = zpci_bus_add_device(zbus, zdev);
410 pr_err("Adding PCI function %08x failed\n", zdev->fid);
415 void zpci_bus_device_unregister(struct zpci_dev *zdev)
417 struct zpci_bus *zbus = zdev->zbus;
420 zbus->function[zdev->devfn] = NULL;