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/sclp.h> 20 21 #define SLOT_NAME_SIZE 10 22 static LIST_HEAD(s390_hotplug_slot_list); 23 24 MODULE_AUTHOR("Jan Glauber <jang@linux.vnet.ibm.com"); 25 MODULE_DESCRIPTION("Hot Plug PCI Controller for System z"); 26 MODULE_LICENSE("GPL"); 27 28 static int zpci_fn_configured(enum zpci_state state) 29 { 30 return state == ZPCI_FN_STATE_CONFIGURED || 31 state == ZPCI_FN_STATE_ONLINE; 32 } 33 34 /* 35 * struct slot - slot information for each *physical* slot 36 */ 37 struct slot { 38 struct list_head slot_list; 39 struct hotplug_slot *hotplug_slot; 40 struct zpci_dev *zdev; 41 }; 42 43 static int enable_slot(struct hotplug_slot *hotplug_slot) 44 { 45 struct slot *slot = hotplug_slot->private; 46 int rc; 47 48 if (slot->zdev->state != ZPCI_FN_STATE_STANDBY) 49 return -EIO; 50 51 rc = sclp_pci_configure(slot->zdev->fid); 52 if (!rc) { 53 slot->zdev->state = ZPCI_FN_STATE_CONFIGURED; 54 /* automatically scan the device after is was configured */ 55 zpci_enable_device(slot->zdev); 56 zpci_scan_device(slot->zdev); 57 } 58 return rc; 59 } 60 61 static int disable_slot(struct hotplug_slot *hotplug_slot) 62 { 63 struct slot *slot = hotplug_slot->private; 64 int rc; 65 66 if (!zpci_fn_configured(slot->zdev->state)) 67 return -EIO; 68 69 /* TODO: we rely on the user to unbind/remove the device, is that plausible 70 * or do we need to trigger that here? 71 */ 72 rc = sclp_pci_deconfigure(slot->zdev->fid); 73 if (!rc) { 74 /* Fixme: better call List-PCI to find the disabled FH 75 for the FID since the FH should be opaque... */ 76 slot->zdev->fh &= 0x7fffffff; 77 slot->zdev->state = ZPCI_FN_STATE_STANDBY; 78 } 79 return rc; 80 } 81 82 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value) 83 { 84 struct slot *slot = hotplug_slot->private; 85 86 switch (slot->zdev->state) { 87 case ZPCI_FN_STATE_STANDBY: 88 *value = 0; 89 break; 90 default: 91 *value = 1; 92 break; 93 } 94 return 0; 95 } 96 97 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value) 98 { 99 /* if the slot exits it always contains a function */ 100 *value = 1; 101 return 0; 102 } 103 104 static void release_slot(struct hotplug_slot *hotplug_slot) 105 { 106 struct slot *slot = hotplug_slot->private; 107 108 pr_debug("%s - physical_slot = %s\n", __func__, hotplug_slot_name(hotplug_slot)); 109 kfree(slot->hotplug_slot->info); 110 kfree(slot->hotplug_slot); 111 kfree(slot); 112 } 113 114 static struct hotplug_slot_ops s390_hotplug_slot_ops = { 115 .enable_slot = enable_slot, 116 .disable_slot = disable_slot, 117 .get_power_status = get_power_status, 118 .get_adapter_status = get_adapter_status, 119 }; 120 121 static int init_pci_slot(struct zpci_dev *zdev) 122 { 123 struct hotplug_slot *hotplug_slot; 124 struct hotplug_slot_info *info; 125 char name[SLOT_NAME_SIZE]; 126 struct slot *slot; 127 int rc; 128 129 if (!zdev) 130 return 0; 131 132 slot = kzalloc(sizeof(*slot), GFP_KERNEL); 133 if (!slot) 134 goto error; 135 136 hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL); 137 if (!hotplug_slot) 138 goto error_hp; 139 hotplug_slot->private = slot; 140 141 slot->hotplug_slot = hotplug_slot; 142 slot->zdev = zdev; 143 144 info = kzalloc(sizeof(*info), GFP_KERNEL); 145 if (!info) 146 goto error_info; 147 hotplug_slot->info = info; 148 149 hotplug_slot->ops = &s390_hotplug_slot_ops; 150 hotplug_slot->release = &release_slot; 151 152 get_power_status(hotplug_slot, &info->power_status); 153 get_adapter_status(hotplug_slot, &info->adapter_status); 154 155 snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid); 156 rc = pci_hp_register(slot->hotplug_slot, zdev->bus, 157 ZPCI_DEVFN, name); 158 if (rc) { 159 pr_err("pci_hp_register failed with error %d\n", rc); 160 goto error_reg; 161 } 162 list_add(&slot->slot_list, &s390_hotplug_slot_list); 163 return 0; 164 165 error_reg: 166 kfree(info); 167 error_info: 168 kfree(hotplug_slot); 169 error_hp: 170 kfree(slot); 171 error: 172 return -ENOMEM; 173 } 174 175 static int __init init_pci_slots(void) 176 { 177 struct zpci_dev *zdev; 178 int device = 0; 179 180 /* 181 * Create a structure for each slot, and register that slot 182 * with the pci_hotplug subsystem. 183 */ 184 mutex_lock(&zpci_list_lock); 185 list_for_each_entry(zdev, &zpci_list, entry) { 186 init_pci_slot(zdev); 187 device++; 188 } 189 190 mutex_unlock(&zpci_list_lock); 191 return (device) ? 0 : -ENODEV; 192 } 193 194 static void exit_pci_slot(struct zpci_dev *zdev) 195 { 196 struct list_head *tmp, *n; 197 struct slot *slot; 198 199 list_for_each_safe(tmp, n, &s390_hotplug_slot_list) { 200 slot = list_entry(tmp, struct slot, slot_list); 201 if (slot->zdev != zdev) 202 continue; 203 list_del(&slot->slot_list); 204 pci_hp_deregister(slot->hotplug_slot); 205 } 206 } 207 208 static void __exit exit_pci_slots(void) 209 { 210 struct list_head *tmp, *n; 211 struct slot *slot; 212 213 /* 214 * Unregister all of our slots with the pci_hotplug subsystem. 215 * Memory will be freed in release_slot() callback after slot's 216 * lifespan is finished. 217 */ 218 list_for_each_safe(tmp, n, &s390_hotplug_slot_list) { 219 slot = list_entry(tmp, struct slot, slot_list); 220 list_del(&slot->slot_list); 221 pci_hp_deregister(slot->hotplug_slot); 222 } 223 } 224 225 static int __init pci_hotplug_s390_init(void) 226 { 227 /* 228 * Do specific initialization stuff for your driver here 229 * like initializing your controller hardware (if any) and 230 * determining the number of slots you have in the system 231 * right now. 232 */ 233 234 if (!pci_probe) 235 return -EOPNOTSUPP; 236 237 /* register callbacks for slot handling from arch code */ 238 mutex_lock(&zpci_list_lock); 239 hotplug_ops.create_slot = init_pci_slot; 240 hotplug_ops.remove_slot = exit_pci_slot; 241 mutex_unlock(&zpci_list_lock); 242 pr_info("registered hotplug slot callbacks\n"); 243 return init_pci_slots(); 244 } 245 246 static void __exit pci_hotplug_s390_exit(void) 247 { 248 exit_pci_slots(); 249 } 250 251 module_init(pci_hotplug_s390_init); 252 module_exit(pci_hotplug_s390_exit); 253