1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * VFIO based Physical Subchannel device driver 4 * 5 * Copyright IBM Corp. 2017 6 * Copyright Red Hat, Inc. 2019 7 * 8 * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> 9 * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com> 10 * Cornelia Huck <cohuck@redhat.com> 11 */ 12 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/device.h> 16 #include <linux/slab.h> 17 #include <linux/uuid.h> 18 #include <linux/mdev.h> 19 20 #include <asm/isc.h> 21 22 #include "ioasm.h" 23 #include "css.h" 24 #include "vfio_ccw_private.h" 25 26 struct workqueue_struct *vfio_ccw_work_q; 27 static struct kmem_cache *vfio_ccw_io_region; 28 static struct kmem_cache *vfio_ccw_cmd_region; 29 30 debug_info_t *vfio_ccw_debug_msg_id; 31 debug_info_t *vfio_ccw_debug_trace_id; 32 33 /* 34 * Helpers 35 */ 36 int vfio_ccw_sch_quiesce(struct subchannel *sch) 37 { 38 struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); 39 DECLARE_COMPLETION_ONSTACK(completion); 40 int iretry, ret = 0; 41 42 spin_lock_irq(sch->lock); 43 if (!sch->schib.pmcw.ena) 44 goto out_unlock; 45 ret = cio_disable_subchannel(sch); 46 if (ret != -EBUSY) 47 goto out_unlock; 48 49 iretry = 255; 50 do { 51 52 ret = cio_cancel_halt_clear(sch, &iretry); 53 54 if (ret == -EIO) { 55 pr_err("vfio_ccw: could not quiesce subchannel 0.%x.%04x!\n", 56 sch->schid.ssid, sch->schid.sch_no); 57 break; 58 } 59 60 /* 61 * Flush all I/O and wait for 62 * cancel/halt/clear completion. 63 */ 64 private->completion = &completion; 65 spin_unlock_irq(sch->lock); 66 67 if (ret == -EBUSY) 68 wait_for_completion_timeout(&completion, 3*HZ); 69 70 private->completion = NULL; 71 flush_workqueue(vfio_ccw_work_q); 72 spin_lock_irq(sch->lock); 73 ret = cio_disable_subchannel(sch); 74 } while (ret == -EBUSY); 75 out_unlock: 76 private->state = VFIO_CCW_STATE_NOT_OPER; 77 spin_unlock_irq(sch->lock); 78 return ret; 79 } 80 81 static void vfio_ccw_sch_io_todo(struct work_struct *work) 82 { 83 struct vfio_ccw_private *private; 84 struct irb *irb; 85 bool is_final; 86 87 private = container_of(work, struct vfio_ccw_private, io_work); 88 irb = &private->irb; 89 90 is_final = !(scsw_actl(&irb->scsw) & 91 (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)); 92 if (scsw_is_solicited(&irb->scsw)) { 93 cp_update_scsw(&private->cp, &irb->scsw); 94 if (is_final && private->state == VFIO_CCW_STATE_CP_PENDING) 95 cp_free(&private->cp); 96 } 97 mutex_lock(&private->io_mutex); 98 memcpy(private->io_region->irb_area, irb, sizeof(*irb)); 99 mutex_unlock(&private->io_mutex); 100 101 if (private->mdev && is_final) 102 private->state = VFIO_CCW_STATE_IDLE; 103 104 if (private->io_trigger) 105 eventfd_signal(private->io_trigger, 1); 106 } 107 108 /* 109 * Css driver callbacks 110 */ 111 static void vfio_ccw_sch_irq(struct subchannel *sch) 112 { 113 struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); 114 115 inc_irq_stat(IRQIO_CIO); 116 vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INTERRUPT); 117 } 118 119 static int vfio_ccw_sch_probe(struct subchannel *sch) 120 { 121 struct pmcw *pmcw = &sch->schib.pmcw; 122 struct vfio_ccw_private *private; 123 int ret = -ENOMEM; 124 125 if (pmcw->qf) { 126 dev_warn(&sch->dev, "vfio: ccw: does not support QDIO: %s\n", 127 dev_name(&sch->dev)); 128 return -ENODEV; 129 } 130 131 private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA); 132 if (!private) 133 return -ENOMEM; 134 135 private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX, sizeof(struct ccw1), 136 GFP_KERNEL); 137 if (!private->cp.guest_cp) 138 goto out_free; 139 140 private->io_region = kmem_cache_zalloc(vfio_ccw_io_region, 141 GFP_KERNEL | GFP_DMA); 142 if (!private->io_region) 143 goto out_free; 144 145 private->cmd_region = kmem_cache_zalloc(vfio_ccw_cmd_region, 146 GFP_KERNEL | GFP_DMA); 147 if (!private->cmd_region) 148 goto out_free; 149 150 private->sch = sch; 151 dev_set_drvdata(&sch->dev, private); 152 mutex_init(&private->io_mutex); 153 154 spin_lock_irq(sch->lock); 155 private->state = VFIO_CCW_STATE_NOT_OPER; 156 sch->isc = VFIO_CCW_ISC; 157 ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch); 158 spin_unlock_irq(sch->lock); 159 if (ret) 160 goto out_free; 161 162 INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo); 163 atomic_set(&private->avail, 1); 164 private->state = VFIO_CCW_STATE_STANDBY; 165 166 ret = vfio_ccw_mdev_reg(sch); 167 if (ret) 168 goto out_disable; 169 170 if (dev_get_uevent_suppress(&sch->dev)) { 171 dev_set_uevent_suppress(&sch->dev, 0); 172 kobject_uevent(&sch->dev.kobj, KOBJ_ADD); 173 } 174 175 VFIO_CCW_MSG_EVENT(4, "bound to subchannel %x.%x.%04x\n", 176 sch->schid.cssid, sch->schid.ssid, 177 sch->schid.sch_no); 178 return 0; 179 180 out_disable: 181 cio_disable_subchannel(sch); 182 out_free: 183 dev_set_drvdata(&sch->dev, NULL); 184 if (private->cmd_region) 185 kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); 186 if (private->io_region) 187 kmem_cache_free(vfio_ccw_io_region, private->io_region); 188 kfree(private->cp.guest_cp); 189 kfree(private); 190 return ret; 191 } 192 193 static int vfio_ccw_sch_remove(struct subchannel *sch) 194 { 195 struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); 196 197 vfio_ccw_sch_quiesce(sch); 198 199 vfio_ccw_mdev_unreg(sch); 200 201 dev_set_drvdata(&sch->dev, NULL); 202 203 kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); 204 kmem_cache_free(vfio_ccw_io_region, private->io_region); 205 kfree(private->cp.guest_cp); 206 kfree(private); 207 208 VFIO_CCW_MSG_EVENT(4, "unbound from subchannel %x.%x.%04x\n", 209 sch->schid.cssid, sch->schid.ssid, 210 sch->schid.sch_no); 211 return 0; 212 } 213 214 static void vfio_ccw_sch_shutdown(struct subchannel *sch) 215 { 216 vfio_ccw_sch_quiesce(sch); 217 } 218 219 /** 220 * vfio_ccw_sch_event - process subchannel event 221 * @sch: subchannel 222 * @process: non-zero if function is called in process context 223 * 224 * An unspecified event occurred for this subchannel. Adjust data according 225 * to the current operational state of the subchannel. Return zero when the 226 * event has been handled sufficiently or -EAGAIN when this function should 227 * be called again in process context. 228 */ 229 static int vfio_ccw_sch_event(struct subchannel *sch, int process) 230 { 231 struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); 232 unsigned long flags; 233 int rc = -EAGAIN; 234 235 spin_lock_irqsave(sch->lock, flags); 236 if (!device_is_registered(&sch->dev)) 237 goto out_unlock; 238 239 if (work_pending(&sch->todo_work)) 240 goto out_unlock; 241 242 if (cio_update_schib(sch)) { 243 vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); 244 rc = 0; 245 goto out_unlock; 246 } 247 248 private = dev_get_drvdata(&sch->dev); 249 if (private->state == VFIO_CCW_STATE_NOT_OPER) { 250 private->state = private->mdev ? VFIO_CCW_STATE_IDLE : 251 VFIO_CCW_STATE_STANDBY; 252 } 253 rc = 0; 254 255 out_unlock: 256 spin_unlock_irqrestore(sch->lock, flags); 257 258 return rc; 259 } 260 261 static struct css_device_id vfio_ccw_sch_ids[] = { 262 { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, }, 263 { /* end of list */ }, 264 }; 265 MODULE_DEVICE_TABLE(css, vfio_ccw_sch_ids); 266 267 static struct css_driver vfio_ccw_sch_driver = { 268 .drv = { 269 .name = "vfio_ccw", 270 .owner = THIS_MODULE, 271 }, 272 .subchannel_type = vfio_ccw_sch_ids, 273 .irq = vfio_ccw_sch_irq, 274 .probe = vfio_ccw_sch_probe, 275 .remove = vfio_ccw_sch_remove, 276 .shutdown = vfio_ccw_sch_shutdown, 277 .sch_event = vfio_ccw_sch_event, 278 }; 279 280 static int __init vfio_ccw_debug_init(void) 281 { 282 vfio_ccw_debug_msg_id = debug_register("vfio_ccw_msg", 16, 1, 283 11 * sizeof(long)); 284 if (!vfio_ccw_debug_msg_id) 285 goto out_unregister; 286 debug_register_view(vfio_ccw_debug_msg_id, &debug_sprintf_view); 287 debug_set_level(vfio_ccw_debug_msg_id, 2); 288 vfio_ccw_debug_trace_id = debug_register("vfio_ccw_trace", 16, 1, 16); 289 if (!vfio_ccw_debug_trace_id) 290 goto out_unregister; 291 debug_register_view(vfio_ccw_debug_trace_id, &debug_hex_ascii_view); 292 debug_set_level(vfio_ccw_debug_trace_id, 2); 293 return 0; 294 295 out_unregister: 296 debug_unregister(vfio_ccw_debug_msg_id); 297 debug_unregister(vfio_ccw_debug_trace_id); 298 return -1; 299 } 300 301 static void vfio_ccw_debug_exit(void) 302 { 303 debug_unregister(vfio_ccw_debug_msg_id); 304 debug_unregister(vfio_ccw_debug_trace_id); 305 } 306 307 static int __init vfio_ccw_sch_init(void) 308 { 309 int ret; 310 311 ret = vfio_ccw_debug_init(); 312 if (ret) 313 return ret; 314 315 vfio_ccw_work_q = create_singlethread_workqueue("vfio-ccw"); 316 if (!vfio_ccw_work_q) { 317 ret = -ENOMEM; 318 goto out_err; 319 } 320 321 vfio_ccw_io_region = kmem_cache_create_usercopy("vfio_ccw_io_region", 322 sizeof(struct ccw_io_region), 0, 323 SLAB_ACCOUNT, 0, 324 sizeof(struct ccw_io_region), NULL); 325 if (!vfio_ccw_io_region) { 326 ret = -ENOMEM; 327 goto out_err; 328 } 329 330 vfio_ccw_cmd_region = kmem_cache_create_usercopy("vfio_ccw_cmd_region", 331 sizeof(struct ccw_cmd_region), 0, 332 SLAB_ACCOUNT, 0, 333 sizeof(struct ccw_cmd_region), NULL); 334 if (!vfio_ccw_cmd_region) { 335 ret = -ENOMEM; 336 goto out_err; 337 } 338 339 isc_register(VFIO_CCW_ISC); 340 ret = css_driver_register(&vfio_ccw_sch_driver); 341 if (ret) { 342 isc_unregister(VFIO_CCW_ISC); 343 goto out_err; 344 } 345 346 return ret; 347 348 out_err: 349 kmem_cache_destroy(vfio_ccw_cmd_region); 350 kmem_cache_destroy(vfio_ccw_io_region); 351 destroy_workqueue(vfio_ccw_work_q); 352 vfio_ccw_debug_exit(); 353 return ret; 354 } 355 356 static void __exit vfio_ccw_sch_exit(void) 357 { 358 css_driver_unregister(&vfio_ccw_sch_driver); 359 isc_unregister(VFIO_CCW_ISC); 360 kmem_cache_destroy(vfio_ccw_io_region); 361 kmem_cache_destroy(vfio_ccw_cmd_region); 362 destroy_workqueue(vfio_ccw_work_q); 363 vfio_ccw_debug_exit(); 364 } 365 module_init(vfio_ccw_sch_init); 366 module_exit(vfio_ccw_sch_exit); 367 368 MODULE_LICENSE("GPL v2"); 369