1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * PCI Hot Plug Controller Driver for System z 4 * 5 * Copyright 2012 IBM Corp. 6 * 7 * Author(s): 8 * Jan Glauber <jang@linux.vnet.ibm.com> 9 */ 10 11 #define KMSG_COMPONENT "zpci" 12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 13 14 #include <linux/kernel.h> 15 #include <linux/slab.h> 16 #include <linux/pci.h> 17 #include <linux/pci_hotplug.h> 18 #include <asm/pci_debug.h> 19 #include <asm/sclp.h> 20 21 #define SLOT_NAME_SIZE 10 22 static LIST_HEAD(s390_hotplug_slot_list); 23 24 static int zpci_fn_configured(enum zpci_state state) 25 { 26 return state == ZPCI_FN_STATE_CONFIGURED || 27 state == ZPCI_FN_STATE_ONLINE; 28 } 29 30 /* 31 * struct slot - slot information for each *physical* slot 32 */ 33 struct slot { 34 struct list_head slot_list; 35 struct hotplug_slot hotplug_slot; 36 struct zpci_dev *zdev; 37 }; 38 39 static inline struct slot *to_slot(struct hotplug_slot *hotplug_slot) 40 { 41 return container_of(hotplug_slot, struct slot, hotplug_slot); 42 } 43 44 static inline int slot_configure(struct slot *slot) 45 { 46 int ret = sclp_pci_configure(slot->zdev->fid); 47 48 zpci_dbg(3, "conf fid:%x, rc:%d\n", slot->zdev->fid, ret); 49 if (!ret) 50 slot->zdev->state = ZPCI_FN_STATE_CONFIGURED; 51 52 return ret; 53 } 54 55 static inline int slot_deconfigure(struct slot *slot) 56 { 57 int ret = sclp_pci_deconfigure(slot->zdev->fid); 58 59 zpci_dbg(3, "deconf fid:%x, rc:%d\n", slot->zdev->fid, ret); 60 if (!ret) 61 slot->zdev->state = ZPCI_FN_STATE_STANDBY; 62 63 return ret; 64 } 65 66 static int enable_slot(struct hotplug_slot *hotplug_slot) 67 { 68 struct slot *slot = to_slot(hotplug_slot); 69 int rc; 70 71 if (slot->zdev->state != ZPCI_FN_STATE_STANDBY) 72 return -EIO; 73 74 rc = slot_configure(slot); 75 if (rc) 76 return rc; 77 78 rc = zpci_enable_device(slot->zdev); 79 if (rc) 80 goto out_deconfigure; 81 82 pci_scan_slot(slot->zdev->bus, ZPCI_DEVFN); 83 pci_lock_rescan_remove(); 84 pci_bus_add_devices(slot->zdev->bus); 85 pci_unlock_rescan_remove(); 86 87 return rc; 88 89 out_deconfigure: 90 slot_deconfigure(slot); 91 return rc; 92 } 93 94 static int disable_slot(struct hotplug_slot *hotplug_slot) 95 { 96 struct slot *slot = to_slot(hotplug_slot); 97 struct pci_dev *pdev; 98 int rc; 99 100 if (!zpci_fn_configured(slot->zdev->state)) 101 return -EIO; 102 103 pdev = pci_get_slot(slot->zdev->bus, ZPCI_DEVFN); 104 if (pdev) { 105 pci_stop_and_remove_bus_device_locked(pdev); 106 pci_dev_put(pdev); 107 } 108 109 rc = zpci_disable_device(slot->zdev); 110 if (rc) 111 return rc; 112 113 return slot_deconfigure(slot); 114 } 115 116 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value) 117 { 118 struct slot *slot = to_slot(hotplug_slot); 119 120 switch (slot->zdev->state) { 121 case ZPCI_FN_STATE_STANDBY: 122 *value = 0; 123 break; 124 default: 125 *value = 1; 126 break; 127 } 128 return 0; 129 } 130 131 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value) 132 { 133 /* if the slot exits it always contains a function */ 134 *value = 1; 135 return 0; 136 } 137 138 static const struct hotplug_slot_ops s390_hotplug_slot_ops = { 139 .enable_slot = enable_slot, 140 .disable_slot = disable_slot, 141 .get_power_status = get_power_status, 142 .get_adapter_status = get_adapter_status, 143 }; 144 145 int zpci_init_slot(struct zpci_dev *zdev) 146 { 147 char name[SLOT_NAME_SIZE]; 148 struct slot *slot; 149 int rc; 150 151 if (!zdev) 152 return 0; 153 154 slot = kzalloc(sizeof(*slot), GFP_KERNEL); 155 if (!slot) 156 goto error; 157 158 slot->zdev = zdev; 159 slot->hotplug_slot.ops = &s390_hotplug_slot_ops; 160 161 snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid); 162 rc = pci_hp_register(&slot->hotplug_slot, zdev->bus, 163 ZPCI_DEVFN, name); 164 if (rc) 165 goto error_reg; 166 167 list_add(&slot->slot_list, &s390_hotplug_slot_list); 168 return 0; 169 170 error_reg: 171 kfree(slot); 172 error: 173 return -ENOMEM; 174 } 175 176 void zpci_exit_slot(struct zpci_dev *zdev) 177 { 178 struct slot *slot, *next; 179 180 list_for_each_entry_safe(slot, next, &s390_hotplug_slot_list, 181 slot_list) { 182 if (slot->zdev != zdev) 183 continue; 184 list_del(&slot->slot_list); 185 pci_hp_deregister(&slot->hotplug_slot); 186 kfree(slot); 187 } 188 } 189