1 /* 2 * PCI Hot Plug Controller Driver for System z 3 * 4 * Copyright 2012 IBM Corp. 5 * 6 * Author(s): 7 * Jan Glauber <jang@linux.vnet.ibm.com> 8 */ 9 10 #define COMPONENT "zPCI hpc" 11 #define pr_fmt(fmt) COMPONENT ": " fmt 12 13 #include <linux/module.h> 14 #include <linux/kernel.h> 15 #include <linux/slab.h> 16 #include <linux/pci.h> 17 #include <linux/pci_hotplug.h> 18 #include <linux/init.h> 19 #include <asm/pci_debug.h> 20 #include <asm/sclp.h> 21 22 #define SLOT_NAME_SIZE 10 23 static LIST_HEAD(s390_hotplug_slot_list); 24 25 MODULE_AUTHOR("Jan Glauber <jang@linux.vnet.ibm.com"); 26 MODULE_DESCRIPTION("Hot Plug PCI Controller for System z"); 27 MODULE_LICENSE("GPL"); 28 29 static int zpci_fn_configured(enum zpci_state state) 30 { 31 return state == ZPCI_FN_STATE_CONFIGURED || 32 state == ZPCI_FN_STATE_ONLINE; 33 } 34 35 /* 36 * struct slot - slot information for each *physical* slot 37 */ 38 struct slot { 39 struct list_head slot_list; 40 struct hotplug_slot *hotplug_slot; 41 struct zpci_dev *zdev; 42 }; 43 44 static int enable_slot(struct hotplug_slot *hotplug_slot) 45 { 46 struct slot *slot = hotplug_slot->private; 47 int rc; 48 49 if (slot->zdev->state != ZPCI_FN_STATE_STANDBY) 50 return -EIO; 51 52 rc = sclp_pci_configure(slot->zdev->fid); 53 zpci_dbg(3, "conf fid:%x, rc:%d\n", slot->zdev->fid, rc); 54 if (!rc) { 55 slot->zdev->state = ZPCI_FN_STATE_CONFIGURED; 56 /* automatically scan the device after is was configured */ 57 zpci_enable_device(slot->zdev); 58 zpci_scan_device(slot->zdev); 59 } 60 return rc; 61 } 62 63 static int disable_slot(struct hotplug_slot *hotplug_slot) 64 { 65 struct slot *slot = hotplug_slot->private; 66 int rc; 67 68 if (!zpci_fn_configured(slot->zdev->state)) 69 return -EIO; 70 71 rc = zpci_disable_device(slot->zdev); 72 if (rc) 73 return rc; 74 /* TODO: we rely on the user to unbind/remove the device, is that plausible 75 * or do we need to trigger that here? 76 */ 77 rc = sclp_pci_deconfigure(slot->zdev->fid); 78 zpci_dbg(3, "deconf fid:%x, rc:%d\n", slot->zdev->fid, rc); 79 if (!rc) 80 slot->zdev->state = ZPCI_FN_STATE_STANDBY; 81 return rc; 82 } 83 84 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value) 85 { 86 struct slot *slot = hotplug_slot->private; 87 88 switch (slot->zdev->state) { 89 case ZPCI_FN_STATE_STANDBY: 90 *value = 0; 91 break; 92 default: 93 *value = 1; 94 break; 95 } 96 return 0; 97 } 98 99 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value) 100 { 101 /* if the slot exits it always contains a function */ 102 *value = 1; 103 return 0; 104 } 105 106 static void release_slot(struct hotplug_slot *hotplug_slot) 107 { 108 struct slot *slot = hotplug_slot->private; 109 110 pr_debug("%s - physical_slot = %s\n", __func__, hotplug_slot_name(hotplug_slot)); 111 kfree(slot->hotplug_slot->info); 112 kfree(slot->hotplug_slot); 113 kfree(slot); 114 } 115 116 static struct hotplug_slot_ops s390_hotplug_slot_ops = { 117 .enable_slot = enable_slot, 118 .disable_slot = disable_slot, 119 .get_power_status = get_power_status, 120 .get_adapter_status = get_adapter_status, 121 }; 122 123 static int init_pci_slot(struct zpci_dev *zdev) 124 { 125 struct hotplug_slot *hotplug_slot; 126 struct hotplug_slot_info *info; 127 char name[SLOT_NAME_SIZE]; 128 struct slot *slot; 129 int rc; 130 131 if (!zdev) 132 return 0; 133 134 slot = kzalloc(sizeof(*slot), GFP_KERNEL); 135 if (!slot) 136 goto error; 137 138 hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL); 139 if (!hotplug_slot) 140 goto error_hp; 141 hotplug_slot->private = slot; 142 143 slot->hotplug_slot = hotplug_slot; 144 slot->zdev = zdev; 145 146 info = kzalloc(sizeof(*info), GFP_KERNEL); 147 if (!info) 148 goto error_info; 149 hotplug_slot->info = info; 150 151 hotplug_slot->ops = &s390_hotplug_slot_ops; 152 hotplug_slot->release = &release_slot; 153 154 get_power_status(hotplug_slot, &info->power_status); 155 get_adapter_status(hotplug_slot, &info->adapter_status); 156 157 snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid); 158 rc = pci_hp_register(slot->hotplug_slot, zdev->bus, 159 ZPCI_DEVFN, name); 160 if (rc) { 161 pr_err("pci_hp_register failed with error %d\n", rc); 162 goto error_reg; 163 } 164 list_add(&slot->slot_list, &s390_hotplug_slot_list); 165 return 0; 166 167 error_reg: 168 kfree(info); 169 error_info: 170 kfree(hotplug_slot); 171 error_hp: 172 kfree(slot); 173 error: 174 return -ENOMEM; 175 } 176 177 static void exit_pci_slot(struct zpci_dev *zdev) 178 { 179 struct list_head *tmp, *n; 180 struct slot *slot; 181 182 list_for_each_safe(tmp, n, &s390_hotplug_slot_list) { 183 slot = list_entry(tmp, struct slot, slot_list); 184 if (slot->zdev != zdev) 185 continue; 186 list_del(&slot->slot_list); 187 pci_hp_deregister(slot->hotplug_slot); 188 } 189 } 190 191 static struct pci_hp_callback_ops hp_ops = { 192 .create_slot = init_pci_slot, 193 .remove_slot = exit_pci_slot, 194 }; 195 196 static void __init init_pci_slots(void) 197 { 198 struct zpci_dev *zdev; 199 200 /* 201 * Create a structure for each slot, and register that slot 202 * with the pci_hotplug subsystem. 203 */ 204 mutex_lock(&zpci_list_lock); 205 list_for_each_entry(zdev, &zpci_list, entry) { 206 init_pci_slot(zdev); 207 } 208 mutex_unlock(&zpci_list_lock); 209 } 210 211 static void __exit exit_pci_slots(void) 212 { 213 struct list_head *tmp, *n; 214 struct slot *slot; 215 216 /* 217 * Unregister all of our slots with the pci_hotplug subsystem. 218 * Memory will be freed in release_slot() callback after slot's 219 * lifespan is finished. 220 */ 221 list_for_each_safe(tmp, n, &s390_hotplug_slot_list) { 222 slot = list_entry(tmp, struct slot, slot_list); 223 list_del(&slot->slot_list); 224 pci_hp_deregister(slot->hotplug_slot); 225 } 226 } 227 228 static int __init pci_hotplug_s390_init(void) 229 { 230 if (!s390_pci_probe) 231 return -EOPNOTSUPP; 232 233 zpci_register_hp_ops(&hp_ops); 234 init_pci_slots(); 235 236 return 0; 237 } 238 239 static void __exit pci_hotplug_s390_exit(void) 240 { 241 exit_pci_slots(); 242 zpci_deregister_hp_ops(); 243 } 244 245 module_init(pci_hotplug_s390_init); 246 module_exit(pci_hotplug_s390_exit); 247