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 VFIO_CCW_MSG_EVENT(4, "bound to subchannel %x.%x.%04x\n", 171 sch->schid.cssid, sch->schid.ssid, 172 sch->schid.sch_no); 173 return 0; 174 175 out_disable: 176 cio_disable_subchannel(sch); 177 out_free: 178 dev_set_drvdata(&sch->dev, NULL); 179 if (private->cmd_region) 180 kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); 181 if (private->io_region) 182 kmem_cache_free(vfio_ccw_io_region, private->io_region); 183 kfree(private->cp.guest_cp); 184 kfree(private); 185 return ret; 186 } 187 188 static int vfio_ccw_sch_remove(struct subchannel *sch) 189 { 190 struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); 191 192 vfio_ccw_sch_quiesce(sch); 193 194 vfio_ccw_mdev_unreg(sch); 195 196 dev_set_drvdata(&sch->dev, NULL); 197 198 kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); 199 kmem_cache_free(vfio_ccw_io_region, private->io_region); 200 kfree(private->cp.guest_cp); 201 kfree(private); 202 203 VFIO_CCW_MSG_EVENT(4, "unbound from subchannel %x.%x.%04x\n", 204 sch->schid.cssid, sch->schid.ssid, 205 sch->schid.sch_no); 206 return 0; 207 } 208 209 static void vfio_ccw_sch_shutdown(struct subchannel *sch) 210 { 211 vfio_ccw_sch_quiesce(sch); 212 } 213 214 /** 215 * vfio_ccw_sch_event - process subchannel event 216 * @sch: subchannel 217 * @process: non-zero if function is called in process context 218 * 219 * An unspecified event occurred for this subchannel. Adjust data according 220 * to the current operational state of the subchannel. Return zero when the 221 * event has been handled sufficiently or -EAGAIN when this function should 222 * be called again in process context. 223 */ 224 static int vfio_ccw_sch_event(struct subchannel *sch, int process) 225 { 226 struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); 227 unsigned long flags; 228 int rc = -EAGAIN; 229 230 spin_lock_irqsave(sch->lock, flags); 231 if (!device_is_registered(&sch->dev)) 232 goto out_unlock; 233 234 if (work_pending(&sch->todo_work)) 235 goto out_unlock; 236 237 if (cio_update_schib(sch)) { 238 vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); 239 rc = 0; 240 goto out_unlock; 241 } 242 243 private = dev_get_drvdata(&sch->dev); 244 if (private->state == VFIO_CCW_STATE_NOT_OPER) { 245 private->state = private->mdev ? VFIO_CCW_STATE_IDLE : 246 VFIO_CCW_STATE_STANDBY; 247 } 248 rc = 0; 249 250 out_unlock: 251 spin_unlock_irqrestore(sch->lock, flags); 252 253 return rc; 254 } 255 256 static struct css_device_id vfio_ccw_sch_ids[] = { 257 { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, }, 258 { /* end of list */ }, 259 }; 260 MODULE_DEVICE_TABLE(css, vfio_ccw_sch_ids); 261 262 static struct css_driver vfio_ccw_sch_driver = { 263 .drv = { 264 .name = "vfio_ccw", 265 .owner = THIS_MODULE, 266 }, 267 .subchannel_type = vfio_ccw_sch_ids, 268 .irq = vfio_ccw_sch_irq, 269 .probe = vfio_ccw_sch_probe, 270 .remove = vfio_ccw_sch_remove, 271 .shutdown = vfio_ccw_sch_shutdown, 272 .sch_event = vfio_ccw_sch_event, 273 }; 274 275 static int __init vfio_ccw_debug_init(void) 276 { 277 vfio_ccw_debug_msg_id = debug_register("vfio_ccw_msg", 16, 1, 278 11 * sizeof(long)); 279 if (!vfio_ccw_debug_msg_id) 280 goto out_unregister; 281 debug_register_view(vfio_ccw_debug_msg_id, &debug_sprintf_view); 282 debug_set_level(vfio_ccw_debug_msg_id, 2); 283 vfio_ccw_debug_trace_id = debug_register("vfio_ccw_trace", 16, 1, 16); 284 if (!vfio_ccw_debug_trace_id) 285 goto out_unregister; 286 debug_register_view(vfio_ccw_debug_trace_id, &debug_hex_ascii_view); 287 debug_set_level(vfio_ccw_debug_trace_id, 2); 288 return 0; 289 290 out_unregister: 291 debug_unregister(vfio_ccw_debug_msg_id); 292 debug_unregister(vfio_ccw_debug_trace_id); 293 return -1; 294 } 295 296 static void vfio_ccw_debug_exit(void) 297 { 298 debug_unregister(vfio_ccw_debug_msg_id); 299 debug_unregister(vfio_ccw_debug_trace_id); 300 } 301 302 static int __init vfio_ccw_sch_init(void) 303 { 304 int ret; 305 306 ret = vfio_ccw_debug_init(); 307 if (ret) 308 return ret; 309 310 vfio_ccw_work_q = create_singlethread_workqueue("vfio-ccw"); 311 if (!vfio_ccw_work_q) { 312 ret = -ENOMEM; 313 goto out_err; 314 } 315 316 vfio_ccw_io_region = kmem_cache_create_usercopy("vfio_ccw_io_region", 317 sizeof(struct ccw_io_region), 0, 318 SLAB_ACCOUNT, 0, 319 sizeof(struct ccw_io_region), NULL); 320 if (!vfio_ccw_io_region) { 321 ret = -ENOMEM; 322 goto out_err; 323 } 324 325 vfio_ccw_cmd_region = kmem_cache_create_usercopy("vfio_ccw_cmd_region", 326 sizeof(struct ccw_cmd_region), 0, 327 SLAB_ACCOUNT, 0, 328 sizeof(struct ccw_cmd_region), NULL); 329 if (!vfio_ccw_cmd_region) { 330 ret = -ENOMEM; 331 goto out_err; 332 } 333 334 isc_register(VFIO_CCW_ISC); 335 ret = css_driver_register(&vfio_ccw_sch_driver); 336 if (ret) { 337 isc_unregister(VFIO_CCW_ISC); 338 goto out_err; 339 } 340 341 return ret; 342 343 out_err: 344 kmem_cache_destroy(vfio_ccw_cmd_region); 345 kmem_cache_destroy(vfio_ccw_io_region); 346 destroy_workqueue(vfio_ccw_work_q); 347 vfio_ccw_debug_exit(); 348 return ret; 349 } 350 351 static void __exit vfio_ccw_sch_exit(void) 352 { 353 css_driver_unregister(&vfio_ccw_sch_driver); 354 isc_unregister(VFIO_CCW_ISC); 355 kmem_cache_destroy(vfio_ccw_io_region); 356 kmem_cache_destroy(vfio_ccw_cmd_region); 357 destroy_workqueue(vfio_ccw_work_q); 358 vfio_ccw_debug_exit(); 359 } 360 module_init(vfio_ccw_sch_init); 361 module_exit(vfio_ccw_sch_exit); 362 363 MODULE_LICENSE("GPL v2"); 364