1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * (C) Copyright Linus Torvalds 1999 4 * (C) Copyright Johannes Erdfelt 1999-2001 5 * (C) Copyright Andreas Gal 1999 6 * (C) Copyright Gregory P. Smith 1999 7 * (C) Copyright Deti Fliegl 1999 8 * (C) Copyright Randy Dunlap 2000 9 * (C) Copyright David Brownell 2000-2002 10 */ 11 12 #include <linux/bcd.h> 13 #include <linux/module.h> 14 #include <linux/version.h> 15 #include <linux/kernel.h> 16 #include <linux/sched/task_stack.h> 17 #include <linux/slab.h> 18 #include <linux/completion.h> 19 #include <linux/utsname.h> 20 #include <linux/mm.h> 21 #include <asm/io.h> 22 #include <linux/device.h> 23 #include <linux/dma-mapping.h> 24 #include <linux/mutex.h> 25 #include <asm/irq.h> 26 #include <asm/byteorder.h> 27 #include <asm/unaligned.h> 28 #include <linux/platform_device.h> 29 #include <linux/workqueue.h> 30 #include <linux/pm_runtime.h> 31 #include <linux/types.h> 32 33 #include <linux/phy/phy.h> 34 #include <linux/usb.h> 35 #include <linux/usb/hcd.h> 36 #include <linux/usb/otg.h> 37 38 #include "usb.h" 39 #include "phy.h" 40 41 42 /*-------------------------------------------------------------------------*/ 43 44 /* 45 * USB Host Controller Driver framework 46 * 47 * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing 48 * HCD-specific behaviors/bugs. 49 * 50 * This does error checks, tracks devices and urbs, and delegates to a 51 * "hc_driver" only for code (and data) that really needs to know about 52 * hardware differences. That includes root hub registers, i/o queues, 53 * and so on ... but as little else as possible. 54 * 55 * Shared code includes most of the "root hub" code (these are emulated, 56 * though each HC's hardware works differently) and PCI glue, plus request 57 * tracking overhead. The HCD code should only block on spinlocks or on 58 * hardware handshaking; blocking on software events (such as other kernel 59 * threads releasing resources, or completing actions) is all generic. 60 * 61 * Happens the USB 2.0 spec says this would be invisible inside the "USBD", 62 * and includes mostly a "HCDI" (HCD Interface) along with some APIs used 63 * only by the hub driver ... and that neither should be seen or used by 64 * usb client device drivers. 65 * 66 * Contributors of ideas or unattributed patches include: David Brownell, 67 * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ... 68 * 69 * HISTORY: 70 * 2002-02-21 Pull in most of the usb_bus support from usb.c; some 71 * associated cleanup. "usb_hcd" still != "usb_bus". 72 * 2001-12-12 Initial patch version for Linux 2.5.1 kernel. 73 */ 74 75 /*-------------------------------------------------------------------------*/ 76 77 /* Keep track of which host controller drivers are loaded */ 78 unsigned long usb_hcds_loaded; 79 EXPORT_SYMBOL_GPL(usb_hcds_loaded); 80 81 /* host controllers we manage */ 82 DEFINE_IDR (usb_bus_idr); 83 EXPORT_SYMBOL_GPL (usb_bus_idr); 84 85 /* used when allocating bus numbers */ 86 #define USB_MAXBUS 64 87 88 /* used when updating list of hcds */ 89 DEFINE_MUTEX(usb_bus_idr_lock); /* exported only for usbfs */ 90 EXPORT_SYMBOL_GPL (usb_bus_idr_lock); 91 92 /* used for controlling access to virtual root hubs */ 93 static DEFINE_SPINLOCK(hcd_root_hub_lock); 94 95 /* used when updating an endpoint's URB list */ 96 static DEFINE_SPINLOCK(hcd_urb_list_lock); 97 98 /* used to protect against unlinking URBs after the device is gone */ 99 static DEFINE_SPINLOCK(hcd_urb_unlink_lock); 100 101 /* wait queue for synchronous unlinks */ 102 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue); 103 104 static inline int is_root_hub(struct usb_device *udev) 105 { 106 return (udev->parent == NULL); 107 } 108 109 /*-------------------------------------------------------------------------*/ 110 111 /* 112 * Sharable chunks of root hub code. 113 */ 114 115 /*-------------------------------------------------------------------------*/ 116 #define KERNEL_REL bin2bcd(((LINUX_VERSION_CODE >> 16) & 0x0ff)) 117 #define KERNEL_VER bin2bcd(((LINUX_VERSION_CODE >> 8) & 0x0ff)) 118 119 /* usb 3.1 root hub device descriptor */ 120 static const u8 usb31_rh_dev_descriptor[18] = { 121 0x12, /* __u8 bLength; */ 122 USB_DT_DEVICE, /* __u8 bDescriptorType; Device */ 123 0x10, 0x03, /* __le16 bcdUSB; v3.1 */ 124 125 0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */ 126 0x00, /* __u8 bDeviceSubClass; */ 127 0x03, /* __u8 bDeviceProtocol; USB 3 hub */ 128 0x09, /* __u8 bMaxPacketSize0; 2^9 = 512 Bytes */ 129 130 0x6b, 0x1d, /* __le16 idVendor; Linux Foundation 0x1d6b */ 131 0x03, 0x00, /* __le16 idProduct; device 0x0003 */ 132 KERNEL_VER, KERNEL_REL, /* __le16 bcdDevice */ 133 134 0x03, /* __u8 iManufacturer; */ 135 0x02, /* __u8 iProduct; */ 136 0x01, /* __u8 iSerialNumber; */ 137 0x01 /* __u8 bNumConfigurations; */ 138 }; 139 140 /* usb 3.0 root hub device descriptor */ 141 static const u8 usb3_rh_dev_descriptor[18] = { 142 0x12, /* __u8 bLength; */ 143 USB_DT_DEVICE, /* __u8 bDescriptorType; Device */ 144 0x00, 0x03, /* __le16 bcdUSB; v3.0 */ 145 146 0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */ 147 0x00, /* __u8 bDeviceSubClass; */ 148 0x03, /* __u8 bDeviceProtocol; USB 3.0 hub */ 149 0x09, /* __u8 bMaxPacketSize0; 2^9 = 512 Bytes */ 150 151 0x6b, 0x1d, /* __le16 idVendor; Linux Foundation 0x1d6b */ 152 0x03, 0x00, /* __le16 idProduct; device 0x0003 */ 153 KERNEL_VER, KERNEL_REL, /* __le16 bcdDevice */ 154 155 0x03, /* __u8 iManufacturer; */ 156 0x02, /* __u8 iProduct; */ 157 0x01, /* __u8 iSerialNumber; */ 158 0x01 /* __u8 bNumConfigurations; */ 159 }; 160 161 /* usb 2.5 (wireless USB 1.0) root hub device descriptor */ 162 static const u8 usb25_rh_dev_descriptor[18] = { 163 0x12, /* __u8 bLength; */ 164 USB_DT_DEVICE, /* __u8 bDescriptorType; Device */ 165 0x50, 0x02, /* __le16 bcdUSB; v2.5 */ 166 167 0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */ 168 0x00, /* __u8 bDeviceSubClass; */ 169 0x00, /* __u8 bDeviceProtocol; [ usb 2.0 no TT ] */ 170 0xFF, /* __u8 bMaxPacketSize0; always 0xFF (WUSB Spec 7.4.1). */ 171 172 0x6b, 0x1d, /* __le16 idVendor; Linux Foundation 0x1d6b */ 173 0x02, 0x00, /* __le16 idProduct; device 0x0002 */ 174 KERNEL_VER, KERNEL_REL, /* __le16 bcdDevice */ 175 176 0x03, /* __u8 iManufacturer; */ 177 0x02, /* __u8 iProduct; */ 178 0x01, /* __u8 iSerialNumber; */ 179 0x01 /* __u8 bNumConfigurations; */ 180 }; 181 182 /* usb 2.0 root hub device descriptor */ 183 static const u8 usb2_rh_dev_descriptor[18] = { 184 0x12, /* __u8 bLength; */ 185 USB_DT_DEVICE, /* __u8 bDescriptorType; Device */ 186 0x00, 0x02, /* __le16 bcdUSB; v2.0 */ 187 188 0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */ 189 0x00, /* __u8 bDeviceSubClass; */ 190 0x00, /* __u8 bDeviceProtocol; [ usb 2.0 no TT ] */ 191 0x40, /* __u8 bMaxPacketSize0; 64 Bytes */ 192 193 0x6b, 0x1d, /* __le16 idVendor; Linux Foundation 0x1d6b */ 194 0x02, 0x00, /* __le16 idProduct; device 0x0002 */ 195 KERNEL_VER, KERNEL_REL, /* __le16 bcdDevice */ 196 197 0x03, /* __u8 iManufacturer; */ 198 0x02, /* __u8 iProduct; */ 199 0x01, /* __u8 iSerialNumber; */ 200 0x01 /* __u8 bNumConfigurations; */ 201 }; 202 203 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */ 204 205 /* usb 1.1 root hub device descriptor */ 206 static const u8 usb11_rh_dev_descriptor[18] = { 207 0x12, /* __u8 bLength; */ 208 USB_DT_DEVICE, /* __u8 bDescriptorType; Device */ 209 0x10, 0x01, /* __le16 bcdUSB; v1.1 */ 210 211 0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */ 212 0x00, /* __u8 bDeviceSubClass; */ 213 0x00, /* __u8 bDeviceProtocol; [ low/full speeds only ] */ 214 0x40, /* __u8 bMaxPacketSize0; 64 Bytes */ 215 216 0x6b, 0x1d, /* __le16 idVendor; Linux Foundation 0x1d6b */ 217 0x01, 0x00, /* __le16 idProduct; device 0x0001 */ 218 KERNEL_VER, KERNEL_REL, /* __le16 bcdDevice */ 219 220 0x03, /* __u8 iManufacturer; */ 221 0x02, /* __u8 iProduct; */ 222 0x01, /* __u8 iSerialNumber; */ 223 0x01 /* __u8 bNumConfigurations; */ 224 }; 225 226 227 /*-------------------------------------------------------------------------*/ 228 229 /* Configuration descriptors for our root hubs */ 230 231 static const u8 fs_rh_config_descriptor[] = { 232 233 /* one configuration */ 234 0x09, /* __u8 bLength; */ 235 USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */ 236 0x19, 0x00, /* __le16 wTotalLength; */ 237 0x01, /* __u8 bNumInterfaces; (1) */ 238 0x01, /* __u8 bConfigurationValue; */ 239 0x00, /* __u8 iConfiguration; */ 240 0xc0, /* __u8 bmAttributes; 241 Bit 7: must be set, 242 6: Self-powered, 243 5: Remote wakeup, 244 4..0: resvd */ 245 0x00, /* __u8 MaxPower; */ 246 247 /* USB 1.1: 248 * USB 2.0, single TT organization (mandatory): 249 * one interface, protocol 0 250 * 251 * USB 2.0, multiple TT organization (optional): 252 * two interfaces, protocols 1 (like single TT) 253 * and 2 (multiple TT mode) ... config is 254 * sometimes settable 255 * NOT IMPLEMENTED 256 */ 257 258 /* one interface */ 259 0x09, /* __u8 if_bLength; */ 260 USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */ 261 0x00, /* __u8 if_bInterfaceNumber; */ 262 0x00, /* __u8 if_bAlternateSetting; */ 263 0x01, /* __u8 if_bNumEndpoints; */ 264 0x09, /* __u8 if_bInterfaceClass; HUB_CLASSCODE */ 265 0x00, /* __u8 if_bInterfaceSubClass; */ 266 0x00, /* __u8 if_bInterfaceProtocol; [usb1.1 or single tt] */ 267 0x00, /* __u8 if_iInterface; */ 268 269 /* one endpoint (status change endpoint) */ 270 0x07, /* __u8 ep_bLength; */ 271 USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */ 272 0x81, /* __u8 ep_bEndpointAddress; IN Endpoint 1 */ 273 0x03, /* __u8 ep_bmAttributes; Interrupt */ 274 0x02, 0x00, /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */ 275 0xff /* __u8 ep_bInterval; (255ms -- usb 2.0 spec) */ 276 }; 277 278 static const u8 hs_rh_config_descriptor[] = { 279 280 /* one configuration */ 281 0x09, /* __u8 bLength; */ 282 USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */ 283 0x19, 0x00, /* __le16 wTotalLength; */ 284 0x01, /* __u8 bNumInterfaces; (1) */ 285 0x01, /* __u8 bConfigurationValue; */ 286 0x00, /* __u8 iConfiguration; */ 287 0xc0, /* __u8 bmAttributes; 288 Bit 7: must be set, 289 6: Self-powered, 290 5: Remote wakeup, 291 4..0: resvd */ 292 0x00, /* __u8 MaxPower; */ 293 294 /* USB 1.1: 295 * USB 2.0, single TT organization (mandatory): 296 * one interface, protocol 0 297 * 298 * USB 2.0, multiple TT organization (optional): 299 * two interfaces, protocols 1 (like single TT) 300 * and 2 (multiple TT mode) ... config is 301 * sometimes settable 302 * NOT IMPLEMENTED 303 */ 304 305 /* one interface */ 306 0x09, /* __u8 if_bLength; */ 307 USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */ 308 0x00, /* __u8 if_bInterfaceNumber; */ 309 0x00, /* __u8 if_bAlternateSetting; */ 310 0x01, /* __u8 if_bNumEndpoints; */ 311 0x09, /* __u8 if_bInterfaceClass; HUB_CLASSCODE */ 312 0x00, /* __u8 if_bInterfaceSubClass; */ 313 0x00, /* __u8 if_bInterfaceProtocol; [usb1.1 or single tt] */ 314 0x00, /* __u8 if_iInterface; */ 315 316 /* one endpoint (status change endpoint) */ 317 0x07, /* __u8 ep_bLength; */ 318 USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */ 319 0x81, /* __u8 ep_bEndpointAddress; IN Endpoint 1 */ 320 0x03, /* __u8 ep_bmAttributes; Interrupt */ 321 /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) 322 * see hub.c:hub_configure() for details. */ 323 (USB_MAXCHILDREN + 1 + 7) / 8, 0x00, 324 0x0c /* __u8 ep_bInterval; (256ms -- usb 2.0 spec) */ 325 }; 326 327 static const u8 ss_rh_config_descriptor[] = { 328 /* one configuration */ 329 0x09, /* __u8 bLength; */ 330 USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */ 331 0x1f, 0x00, /* __le16 wTotalLength; */ 332 0x01, /* __u8 bNumInterfaces; (1) */ 333 0x01, /* __u8 bConfigurationValue; */ 334 0x00, /* __u8 iConfiguration; */ 335 0xc0, /* __u8 bmAttributes; 336 Bit 7: must be set, 337 6: Self-powered, 338 5: Remote wakeup, 339 4..0: resvd */ 340 0x00, /* __u8 MaxPower; */ 341 342 /* one interface */ 343 0x09, /* __u8 if_bLength; */ 344 USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */ 345 0x00, /* __u8 if_bInterfaceNumber; */ 346 0x00, /* __u8 if_bAlternateSetting; */ 347 0x01, /* __u8 if_bNumEndpoints; */ 348 0x09, /* __u8 if_bInterfaceClass; HUB_CLASSCODE */ 349 0x00, /* __u8 if_bInterfaceSubClass; */ 350 0x00, /* __u8 if_bInterfaceProtocol; */ 351 0x00, /* __u8 if_iInterface; */ 352 353 /* one endpoint (status change endpoint) */ 354 0x07, /* __u8 ep_bLength; */ 355 USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */ 356 0x81, /* __u8 ep_bEndpointAddress; IN Endpoint 1 */ 357 0x03, /* __u8 ep_bmAttributes; Interrupt */ 358 /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) 359 * see hub.c:hub_configure() for details. */ 360 (USB_MAXCHILDREN + 1 + 7) / 8, 0x00, 361 0x0c, /* __u8 ep_bInterval; (256ms -- usb 2.0 spec) */ 362 363 /* one SuperSpeed endpoint companion descriptor */ 364 0x06, /* __u8 ss_bLength */ 365 USB_DT_SS_ENDPOINT_COMP, /* __u8 ss_bDescriptorType; SuperSpeed EP */ 366 /* Companion */ 367 0x00, /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */ 368 0x00, /* __u8 ss_bmAttributes; 1 packet per service interval */ 369 0x02, 0x00 /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */ 370 }; 371 372 /* authorized_default behaviour: 373 * -1 is authorized for all devices except wireless (old behaviour) 374 * 0 is unauthorized for all devices 375 * 1 is authorized for all devices 376 */ 377 static int authorized_default = -1; 378 module_param(authorized_default, int, S_IRUGO|S_IWUSR); 379 MODULE_PARM_DESC(authorized_default, 380 "Default USB device authorization: 0 is not authorized, 1 is " 381 "authorized, -1 is authorized except for wireless USB (default, " 382 "old behaviour"); 383 /*-------------------------------------------------------------------------*/ 384 385 /** 386 * ascii2desc() - Helper routine for producing UTF-16LE string descriptors 387 * @s: Null-terminated ASCII (actually ISO-8859-1) string 388 * @buf: Buffer for USB string descriptor (header + UTF-16LE) 389 * @len: Length (in bytes; may be odd) of descriptor buffer. 390 * 391 * Return: The number of bytes filled in: 2 + 2*strlen(s) or @len, 392 * whichever is less. 393 * 394 * Note: 395 * USB String descriptors can contain at most 126 characters; input 396 * strings longer than that are truncated. 397 */ 398 static unsigned 399 ascii2desc(char const *s, u8 *buf, unsigned len) 400 { 401 unsigned n, t = 2 + 2*strlen(s); 402 403 if (t > 254) 404 t = 254; /* Longest possible UTF string descriptor */ 405 if (len > t) 406 len = t; 407 408 t += USB_DT_STRING << 8; /* Now t is first 16 bits to store */ 409 410 n = len; 411 while (n--) { 412 *buf++ = t; 413 if (!n--) 414 break; 415 *buf++ = t >> 8; 416 t = (unsigned char)*s++; 417 } 418 return len; 419 } 420 421 /** 422 * rh_string() - provides string descriptors for root hub 423 * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor) 424 * @hcd: the host controller for this root hub 425 * @data: buffer for output packet 426 * @len: length of the provided buffer 427 * 428 * Produces either a manufacturer, product or serial number string for the 429 * virtual root hub device. 430 * 431 * Return: The number of bytes filled in: the length of the descriptor or 432 * of the provided buffer, whichever is less. 433 */ 434 static unsigned 435 rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len) 436 { 437 char buf[100]; 438 char const *s; 439 static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04}; 440 441 /* language ids */ 442 switch (id) { 443 case 0: 444 /* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */ 445 /* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */ 446 if (len > 4) 447 len = 4; 448 memcpy(data, langids, len); 449 return len; 450 case 1: 451 /* Serial number */ 452 s = hcd->self.bus_name; 453 break; 454 case 2: 455 /* Product name */ 456 s = hcd->product_desc; 457 break; 458 case 3: 459 /* Manufacturer */ 460 snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname, 461 init_utsname()->release, hcd->driver->description); 462 s = buf; 463 break; 464 default: 465 /* Can't happen; caller guarantees it */ 466 return 0; 467 } 468 469 return ascii2desc(s, data, len); 470 } 471 472 473 /* Root hub control transfers execute synchronously */ 474 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb) 475 { 476 struct usb_ctrlrequest *cmd; 477 u16 typeReq, wValue, wIndex, wLength; 478 u8 *ubuf = urb->transfer_buffer; 479 unsigned len = 0; 480 int status; 481 u8 patch_wakeup = 0; 482 u8 patch_protocol = 0; 483 u16 tbuf_size; 484 u8 *tbuf = NULL; 485 const u8 *bufp; 486 487 might_sleep(); 488 489 spin_lock_irq(&hcd_root_hub_lock); 490 status = usb_hcd_link_urb_to_ep(hcd, urb); 491 spin_unlock_irq(&hcd_root_hub_lock); 492 if (status) 493 return status; 494 urb->hcpriv = hcd; /* Indicate it's queued */ 495 496 cmd = (struct usb_ctrlrequest *) urb->setup_packet; 497 typeReq = (cmd->bRequestType << 8) | cmd->bRequest; 498 wValue = le16_to_cpu (cmd->wValue); 499 wIndex = le16_to_cpu (cmd->wIndex); 500 wLength = le16_to_cpu (cmd->wLength); 501 502 if (wLength > urb->transfer_buffer_length) 503 goto error; 504 505 /* 506 * tbuf should be at least as big as the 507 * USB hub descriptor. 508 */ 509 tbuf_size = max_t(u16, sizeof(struct usb_hub_descriptor), wLength); 510 tbuf = kzalloc(tbuf_size, GFP_KERNEL); 511 if (!tbuf) { 512 status = -ENOMEM; 513 goto err_alloc; 514 } 515 516 bufp = tbuf; 517 518 519 urb->actual_length = 0; 520 switch (typeReq) { 521 522 /* DEVICE REQUESTS */ 523 524 /* The root hub's remote wakeup enable bit is implemented using 525 * driver model wakeup flags. If this system supports wakeup 526 * through USB, userspace may change the default "allow wakeup" 527 * policy through sysfs or these calls. 528 * 529 * Most root hubs support wakeup from downstream devices, for 530 * runtime power management (disabling USB clocks and reducing 531 * VBUS power usage). However, not all of them do so; silicon, 532 * board, and BIOS bugs here are not uncommon, so these can't 533 * be treated quite like external hubs. 534 * 535 * Likewise, not all root hubs will pass wakeup events upstream, 536 * to wake up the whole system. So don't assume root hub and 537 * controller capabilities are identical. 538 */ 539 540 case DeviceRequest | USB_REQ_GET_STATUS: 541 tbuf[0] = (device_may_wakeup(&hcd->self.root_hub->dev) 542 << USB_DEVICE_REMOTE_WAKEUP) 543 | (1 << USB_DEVICE_SELF_POWERED); 544 tbuf[1] = 0; 545 len = 2; 546 break; 547 case DeviceOutRequest | USB_REQ_CLEAR_FEATURE: 548 if (wValue == USB_DEVICE_REMOTE_WAKEUP) 549 device_set_wakeup_enable(&hcd->self.root_hub->dev, 0); 550 else 551 goto error; 552 break; 553 case DeviceOutRequest | USB_REQ_SET_FEATURE: 554 if (device_can_wakeup(&hcd->self.root_hub->dev) 555 && wValue == USB_DEVICE_REMOTE_WAKEUP) 556 device_set_wakeup_enable(&hcd->self.root_hub->dev, 1); 557 else 558 goto error; 559 break; 560 case DeviceRequest | USB_REQ_GET_CONFIGURATION: 561 tbuf[0] = 1; 562 len = 1; 563 /* FALLTHROUGH */ 564 case DeviceOutRequest | USB_REQ_SET_CONFIGURATION: 565 break; 566 case DeviceRequest | USB_REQ_GET_DESCRIPTOR: 567 switch (wValue & 0xff00) { 568 case USB_DT_DEVICE << 8: 569 switch (hcd->speed) { 570 case HCD_USB32: 571 case HCD_USB31: 572 bufp = usb31_rh_dev_descriptor; 573 break; 574 case HCD_USB3: 575 bufp = usb3_rh_dev_descriptor; 576 break; 577 case HCD_USB25: 578 bufp = usb25_rh_dev_descriptor; 579 break; 580 case HCD_USB2: 581 bufp = usb2_rh_dev_descriptor; 582 break; 583 case HCD_USB11: 584 bufp = usb11_rh_dev_descriptor; 585 break; 586 default: 587 goto error; 588 } 589 len = 18; 590 if (hcd->has_tt) 591 patch_protocol = 1; 592 break; 593 case USB_DT_CONFIG << 8: 594 switch (hcd->speed) { 595 case HCD_USB32: 596 case HCD_USB31: 597 case HCD_USB3: 598 bufp = ss_rh_config_descriptor; 599 len = sizeof ss_rh_config_descriptor; 600 break; 601 case HCD_USB25: 602 case HCD_USB2: 603 bufp = hs_rh_config_descriptor; 604 len = sizeof hs_rh_config_descriptor; 605 break; 606 case HCD_USB11: 607 bufp = fs_rh_config_descriptor; 608 len = sizeof fs_rh_config_descriptor; 609 break; 610 default: 611 goto error; 612 } 613 if (device_can_wakeup(&hcd->self.root_hub->dev)) 614 patch_wakeup = 1; 615 break; 616 case USB_DT_STRING << 8: 617 if ((wValue & 0xff) < 4) 618 urb->actual_length = rh_string(wValue & 0xff, 619 hcd, ubuf, wLength); 620 else /* unsupported IDs --> "protocol stall" */ 621 goto error; 622 break; 623 case USB_DT_BOS << 8: 624 goto nongeneric; 625 default: 626 goto error; 627 } 628 break; 629 case DeviceRequest | USB_REQ_GET_INTERFACE: 630 tbuf[0] = 0; 631 len = 1; 632 /* FALLTHROUGH */ 633 case DeviceOutRequest | USB_REQ_SET_INTERFACE: 634 break; 635 case DeviceOutRequest | USB_REQ_SET_ADDRESS: 636 /* wValue == urb->dev->devaddr */ 637 dev_dbg (hcd->self.controller, "root hub device address %d\n", 638 wValue); 639 break; 640 641 /* INTERFACE REQUESTS (no defined feature/status flags) */ 642 643 /* ENDPOINT REQUESTS */ 644 645 case EndpointRequest | USB_REQ_GET_STATUS: 646 /* ENDPOINT_HALT flag */ 647 tbuf[0] = 0; 648 tbuf[1] = 0; 649 len = 2; 650 /* FALLTHROUGH */ 651 case EndpointOutRequest | USB_REQ_CLEAR_FEATURE: 652 case EndpointOutRequest | USB_REQ_SET_FEATURE: 653 dev_dbg (hcd->self.controller, "no endpoint features yet\n"); 654 break; 655 656 /* CLASS REQUESTS (and errors) */ 657 658 default: 659 nongeneric: 660 /* non-generic request */ 661 switch (typeReq) { 662 case GetHubStatus: 663 len = 4; 664 break; 665 case GetPortStatus: 666 if (wValue == HUB_PORT_STATUS) 667 len = 4; 668 else 669 /* other port status types return 8 bytes */ 670 len = 8; 671 break; 672 case GetHubDescriptor: 673 len = sizeof (struct usb_hub_descriptor); 674 break; 675 case DeviceRequest | USB_REQ_GET_DESCRIPTOR: 676 /* len is returned by hub_control */ 677 break; 678 } 679 status = hcd->driver->hub_control (hcd, 680 typeReq, wValue, wIndex, 681 tbuf, wLength); 682 683 if (typeReq == GetHubDescriptor) 684 usb_hub_adjust_deviceremovable(hcd->self.root_hub, 685 (struct usb_hub_descriptor *)tbuf); 686 break; 687 error: 688 /* "protocol stall" on error */ 689 status = -EPIPE; 690 } 691 692 if (status < 0) { 693 len = 0; 694 if (status != -EPIPE) { 695 dev_dbg (hcd->self.controller, 696 "CTRL: TypeReq=0x%x val=0x%x " 697 "idx=0x%x len=%d ==> %d\n", 698 typeReq, wValue, wIndex, 699 wLength, status); 700 } 701 } else if (status > 0) { 702 /* hub_control may return the length of data copied. */ 703 len = status; 704 status = 0; 705 } 706 if (len) { 707 if (urb->transfer_buffer_length < len) 708 len = urb->transfer_buffer_length; 709 urb->actual_length = len; 710 /* always USB_DIR_IN, toward host */ 711 memcpy (ubuf, bufp, len); 712 713 /* report whether RH hardware supports remote wakeup */ 714 if (patch_wakeup && 715 len > offsetof (struct usb_config_descriptor, 716 bmAttributes)) 717 ((struct usb_config_descriptor *)ubuf)->bmAttributes 718 |= USB_CONFIG_ATT_WAKEUP; 719 720 /* report whether RH hardware has an integrated TT */ 721 if (patch_protocol && 722 len > offsetof(struct usb_device_descriptor, 723 bDeviceProtocol)) 724 ((struct usb_device_descriptor *) ubuf)-> 725 bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT; 726 } 727 728 kfree(tbuf); 729 err_alloc: 730 731 /* any errors get returned through the urb completion */ 732 spin_lock_irq(&hcd_root_hub_lock); 733 usb_hcd_unlink_urb_from_ep(hcd, urb); 734 usb_hcd_giveback_urb(hcd, urb, status); 735 spin_unlock_irq(&hcd_root_hub_lock); 736 return 0; 737 } 738 739 /*-------------------------------------------------------------------------*/ 740 741 /* 742 * Root Hub interrupt transfers are polled using a timer if the 743 * driver requests it; otherwise the driver is responsible for 744 * calling usb_hcd_poll_rh_status() when an event occurs. 745 * 746 * Completions are called in_interrupt(), but they may or may not 747 * be in_irq(). 748 */ 749 void usb_hcd_poll_rh_status(struct usb_hcd *hcd) 750 { 751 struct urb *urb; 752 int length; 753 unsigned long flags; 754 char buffer[6]; /* Any root hubs with > 31 ports? */ 755 756 if (unlikely(!hcd->rh_pollable)) 757 return; 758 if (!hcd->uses_new_polling && !hcd->status_urb) 759 return; 760 761 length = hcd->driver->hub_status_data(hcd, buffer); 762 if (length > 0) { 763 764 /* try to complete the status urb */ 765 spin_lock_irqsave(&hcd_root_hub_lock, flags); 766 urb = hcd->status_urb; 767 if (urb) { 768 clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags); 769 hcd->status_urb = NULL; 770 urb->actual_length = length; 771 memcpy(urb->transfer_buffer, buffer, length); 772 773 usb_hcd_unlink_urb_from_ep(hcd, urb); 774 usb_hcd_giveback_urb(hcd, urb, 0); 775 } else { 776 length = 0; 777 set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags); 778 } 779 spin_unlock_irqrestore(&hcd_root_hub_lock, flags); 780 } 781 782 /* The USB 2.0 spec says 256 ms. This is close enough and won't 783 * exceed that limit if HZ is 100. The math is more clunky than 784 * maybe expected, this is to make sure that all timers for USB devices 785 * fire at the same time to give the CPU a break in between */ 786 if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) : 787 (length == 0 && hcd->status_urb != NULL)) 788 mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4)); 789 } 790 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status); 791 792 /* timer callback */ 793 static void rh_timer_func (struct timer_list *t) 794 { 795 struct usb_hcd *_hcd = from_timer(_hcd, t, rh_timer); 796 797 usb_hcd_poll_rh_status(_hcd); 798 } 799 800 /*-------------------------------------------------------------------------*/ 801 802 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb) 803 { 804 int retval; 805 unsigned long flags; 806 unsigned len = 1 + (urb->dev->maxchild / 8); 807 808 spin_lock_irqsave (&hcd_root_hub_lock, flags); 809 if (hcd->status_urb || urb->transfer_buffer_length < len) { 810 dev_dbg (hcd->self.controller, "not queuing rh status urb\n"); 811 retval = -EINVAL; 812 goto done; 813 } 814 815 retval = usb_hcd_link_urb_to_ep(hcd, urb); 816 if (retval) 817 goto done; 818 819 hcd->status_urb = urb; 820 urb->hcpriv = hcd; /* indicate it's queued */ 821 if (!hcd->uses_new_polling) 822 mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4)); 823 824 /* If a status change has already occurred, report it ASAP */ 825 else if (HCD_POLL_PENDING(hcd)) 826 mod_timer(&hcd->rh_timer, jiffies); 827 retval = 0; 828 done: 829 spin_unlock_irqrestore (&hcd_root_hub_lock, flags); 830 return retval; 831 } 832 833 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb) 834 { 835 if (usb_endpoint_xfer_int(&urb->ep->desc)) 836 return rh_queue_status (hcd, urb); 837 if (usb_endpoint_xfer_control(&urb->ep->desc)) 838 return rh_call_control (hcd, urb); 839 return -EINVAL; 840 } 841 842 /*-------------------------------------------------------------------------*/ 843 844 /* Unlinks of root-hub control URBs are legal, but they don't do anything 845 * since these URBs always execute synchronously. 846 */ 847 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) 848 { 849 unsigned long flags; 850 int rc; 851 852 spin_lock_irqsave(&hcd_root_hub_lock, flags); 853 rc = usb_hcd_check_unlink_urb(hcd, urb, status); 854 if (rc) 855 goto done; 856 857 if (usb_endpoint_num(&urb->ep->desc) == 0) { /* Control URB */ 858 ; /* Do nothing */ 859 860 } else { /* Status URB */ 861 if (!hcd->uses_new_polling) 862 del_timer (&hcd->rh_timer); 863 if (urb == hcd->status_urb) { 864 hcd->status_urb = NULL; 865 usb_hcd_unlink_urb_from_ep(hcd, urb); 866 usb_hcd_giveback_urb(hcd, urb, status); 867 } 868 } 869 done: 870 spin_unlock_irqrestore(&hcd_root_hub_lock, flags); 871 return rc; 872 } 873 874 875 876 /* 877 * Show & store the current value of authorized_default 878 */ 879 static ssize_t authorized_default_show(struct device *dev, 880 struct device_attribute *attr, char *buf) 881 { 882 struct usb_device *rh_usb_dev = to_usb_device(dev); 883 struct usb_bus *usb_bus = rh_usb_dev->bus; 884 struct usb_hcd *hcd; 885 886 hcd = bus_to_hcd(usb_bus); 887 return snprintf(buf, PAGE_SIZE, "%u\n", !!HCD_DEV_AUTHORIZED(hcd)); 888 } 889 890 static ssize_t authorized_default_store(struct device *dev, 891 struct device_attribute *attr, 892 const char *buf, size_t size) 893 { 894 ssize_t result; 895 unsigned val; 896 struct usb_device *rh_usb_dev = to_usb_device(dev); 897 struct usb_bus *usb_bus = rh_usb_dev->bus; 898 struct usb_hcd *hcd; 899 900 hcd = bus_to_hcd(usb_bus); 901 result = sscanf(buf, "%u\n", &val); 902 if (result == 1) { 903 if (val) 904 set_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags); 905 else 906 clear_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags); 907 908 result = size; 909 } else { 910 result = -EINVAL; 911 } 912 return result; 913 } 914 static DEVICE_ATTR_RW(authorized_default); 915 916 /* 917 * interface_authorized_default_show - show default authorization status 918 * for USB interfaces 919 * 920 * note: interface_authorized_default is the default value 921 * for initializing the authorized attribute of interfaces 922 */ 923 static ssize_t interface_authorized_default_show(struct device *dev, 924 struct device_attribute *attr, char *buf) 925 { 926 struct usb_device *usb_dev = to_usb_device(dev); 927 struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus); 928 929 return sprintf(buf, "%u\n", !!HCD_INTF_AUTHORIZED(hcd)); 930 } 931 932 /* 933 * interface_authorized_default_store - store default authorization status 934 * for USB interfaces 935 * 936 * note: interface_authorized_default is the default value 937 * for initializing the authorized attribute of interfaces 938 */ 939 static ssize_t interface_authorized_default_store(struct device *dev, 940 struct device_attribute *attr, const char *buf, size_t count) 941 { 942 struct usb_device *usb_dev = to_usb_device(dev); 943 struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus); 944 int rc = count; 945 bool val; 946 947 if (strtobool(buf, &val) != 0) 948 return -EINVAL; 949 950 if (val) 951 set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags); 952 else 953 clear_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags); 954 955 return rc; 956 } 957 static DEVICE_ATTR_RW(interface_authorized_default); 958 959 /* Group all the USB bus attributes */ 960 static struct attribute *usb_bus_attrs[] = { 961 &dev_attr_authorized_default.attr, 962 &dev_attr_interface_authorized_default.attr, 963 NULL, 964 }; 965 966 static const struct attribute_group usb_bus_attr_group = { 967 .name = NULL, /* we want them in the same directory */ 968 .attrs = usb_bus_attrs, 969 }; 970 971 972 973 /*-------------------------------------------------------------------------*/ 974 975 /** 976 * usb_bus_init - shared initialization code 977 * @bus: the bus structure being initialized 978 * 979 * This code is used to initialize a usb_bus structure, memory for which is 980 * separately managed. 981 */ 982 static void usb_bus_init (struct usb_bus *bus) 983 { 984 memset (&bus->devmap, 0, sizeof(struct usb_devmap)); 985 986 bus->devnum_next = 1; 987 988 bus->root_hub = NULL; 989 bus->busnum = -1; 990 bus->bandwidth_allocated = 0; 991 bus->bandwidth_int_reqs = 0; 992 bus->bandwidth_isoc_reqs = 0; 993 mutex_init(&bus->devnum_next_mutex); 994 } 995 996 /*-------------------------------------------------------------------------*/ 997 998 /** 999 * usb_register_bus - registers the USB host controller with the usb core 1000 * @bus: pointer to the bus to register 1001 * Context: !in_interrupt() 1002 * 1003 * Assigns a bus number, and links the controller into usbcore data 1004 * structures so that it can be seen by scanning the bus list. 1005 * 1006 * Return: 0 if successful. A negative error code otherwise. 1007 */ 1008 static int usb_register_bus(struct usb_bus *bus) 1009 { 1010 int result = -E2BIG; 1011 int busnum; 1012 1013 mutex_lock(&usb_bus_idr_lock); 1014 busnum = idr_alloc(&usb_bus_idr, bus, 1, USB_MAXBUS, GFP_KERNEL); 1015 if (busnum < 0) { 1016 pr_err("%s: failed to get bus number\n", usbcore_name); 1017 goto error_find_busnum; 1018 } 1019 bus->busnum = busnum; 1020 mutex_unlock(&usb_bus_idr_lock); 1021 1022 usb_notify_add_bus(bus); 1023 1024 dev_info (bus->controller, "new USB bus registered, assigned bus " 1025 "number %d\n", bus->busnum); 1026 return 0; 1027 1028 error_find_busnum: 1029 mutex_unlock(&usb_bus_idr_lock); 1030 return result; 1031 } 1032 1033 /** 1034 * usb_deregister_bus - deregisters the USB host controller 1035 * @bus: pointer to the bus to deregister 1036 * Context: !in_interrupt() 1037 * 1038 * Recycles the bus number, and unlinks the controller from usbcore data 1039 * structures so that it won't be seen by scanning the bus list. 1040 */ 1041 static void usb_deregister_bus (struct usb_bus *bus) 1042 { 1043 dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum); 1044 1045 /* 1046 * NOTE: make sure that all the devices are removed by the 1047 * controller code, as well as having it call this when cleaning 1048 * itself up 1049 */ 1050 mutex_lock(&usb_bus_idr_lock); 1051 idr_remove(&usb_bus_idr, bus->busnum); 1052 mutex_unlock(&usb_bus_idr_lock); 1053 1054 usb_notify_remove_bus(bus); 1055 } 1056 1057 /** 1058 * register_root_hub - called by usb_add_hcd() to register a root hub 1059 * @hcd: host controller for this root hub 1060 * 1061 * This function registers the root hub with the USB subsystem. It sets up 1062 * the device properly in the device tree and then calls usb_new_device() 1063 * to register the usb device. It also assigns the root hub's USB address 1064 * (always 1). 1065 * 1066 * Return: 0 if successful. A negative error code otherwise. 1067 */ 1068 static int register_root_hub(struct usb_hcd *hcd) 1069 { 1070 struct device *parent_dev = hcd->self.controller; 1071 struct usb_device *usb_dev = hcd->self.root_hub; 1072 const int devnum = 1; 1073 int retval; 1074 1075 usb_dev->devnum = devnum; 1076 usb_dev->bus->devnum_next = devnum + 1; 1077 memset (&usb_dev->bus->devmap.devicemap, 0, 1078 sizeof usb_dev->bus->devmap.devicemap); 1079 set_bit (devnum, usb_dev->bus->devmap.devicemap); 1080 usb_set_device_state(usb_dev, USB_STATE_ADDRESS); 1081 1082 mutex_lock(&usb_bus_idr_lock); 1083 1084 usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64); 1085 retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE); 1086 if (retval != sizeof usb_dev->descriptor) { 1087 mutex_unlock(&usb_bus_idr_lock); 1088 dev_dbg (parent_dev, "can't read %s device descriptor %d\n", 1089 dev_name(&usb_dev->dev), retval); 1090 return (retval < 0) ? retval : -EMSGSIZE; 1091 } 1092 1093 if (le16_to_cpu(usb_dev->descriptor.bcdUSB) >= 0x0201) { 1094 retval = usb_get_bos_descriptor(usb_dev); 1095 if (!retval) { 1096 usb_dev->lpm_capable = usb_device_supports_lpm(usb_dev); 1097 } else if (usb_dev->speed >= USB_SPEED_SUPER) { 1098 mutex_unlock(&usb_bus_idr_lock); 1099 dev_dbg(parent_dev, "can't read %s bos descriptor %d\n", 1100 dev_name(&usb_dev->dev), retval); 1101 return retval; 1102 } 1103 } 1104 1105 retval = usb_new_device (usb_dev); 1106 if (retval) { 1107 dev_err (parent_dev, "can't register root hub for %s, %d\n", 1108 dev_name(&usb_dev->dev), retval); 1109 } else { 1110 spin_lock_irq (&hcd_root_hub_lock); 1111 hcd->rh_registered = 1; 1112 spin_unlock_irq (&hcd_root_hub_lock); 1113 1114 /* Did the HC die before the root hub was registered? */ 1115 if (HCD_DEAD(hcd)) 1116 usb_hc_died (hcd); /* This time clean up */ 1117 } 1118 mutex_unlock(&usb_bus_idr_lock); 1119 1120 return retval; 1121 } 1122 1123 /* 1124 * usb_hcd_start_port_resume - a root-hub port is sending a resume signal 1125 * @bus: the bus which the root hub belongs to 1126 * @portnum: the port which is being resumed 1127 * 1128 * HCDs should call this function when they know that a resume signal is 1129 * being sent to a root-hub port. The root hub will be prevented from 1130 * going into autosuspend until usb_hcd_end_port_resume() is called. 1131 * 1132 * The bus's private lock must be held by the caller. 1133 */ 1134 void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum) 1135 { 1136 unsigned bit = 1 << portnum; 1137 1138 if (!(bus->resuming_ports & bit)) { 1139 bus->resuming_ports |= bit; 1140 pm_runtime_get_noresume(&bus->root_hub->dev); 1141 } 1142 } 1143 EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume); 1144 1145 /* 1146 * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal 1147 * @bus: the bus which the root hub belongs to 1148 * @portnum: the port which is being resumed 1149 * 1150 * HCDs should call this function when they know that a resume signal has 1151 * stopped being sent to a root-hub port. The root hub will be allowed to 1152 * autosuspend again. 1153 * 1154 * The bus's private lock must be held by the caller. 1155 */ 1156 void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum) 1157 { 1158 unsigned bit = 1 << portnum; 1159 1160 if (bus->resuming_ports & bit) { 1161 bus->resuming_ports &= ~bit; 1162 pm_runtime_put_noidle(&bus->root_hub->dev); 1163 } 1164 } 1165 EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume); 1166 1167 /*-------------------------------------------------------------------------*/ 1168 1169 /** 1170 * usb_calc_bus_time - approximate periodic transaction time in nanoseconds 1171 * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH} 1172 * @is_input: true iff the transaction sends data to the host 1173 * @isoc: true for isochronous transactions, false for interrupt ones 1174 * @bytecount: how many bytes in the transaction. 1175 * 1176 * Return: Approximate bus time in nanoseconds for a periodic transaction. 1177 * 1178 * Note: 1179 * See USB 2.0 spec section 5.11.3; only periodic transfers need to be 1180 * scheduled in software, this function is only used for such scheduling. 1181 */ 1182 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount) 1183 { 1184 unsigned long tmp; 1185 1186 switch (speed) { 1187 case USB_SPEED_LOW: /* INTR only */ 1188 if (is_input) { 1189 tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L; 1190 return 64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp; 1191 } else { 1192 tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L; 1193 return 64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp; 1194 } 1195 case USB_SPEED_FULL: /* ISOC or INTR */ 1196 if (isoc) { 1197 tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L; 1198 return ((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp; 1199 } else { 1200 tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L; 1201 return 9107L + BW_HOST_DELAY + tmp; 1202 } 1203 case USB_SPEED_HIGH: /* ISOC or INTR */ 1204 /* FIXME adjust for input vs output */ 1205 if (isoc) 1206 tmp = HS_NSECS_ISO (bytecount); 1207 else 1208 tmp = HS_NSECS (bytecount); 1209 return tmp; 1210 default: 1211 pr_debug ("%s: bogus device speed!\n", usbcore_name); 1212 return -1; 1213 } 1214 } 1215 EXPORT_SYMBOL_GPL(usb_calc_bus_time); 1216 1217 1218 /*-------------------------------------------------------------------------*/ 1219 1220 /* 1221 * Generic HC operations. 1222 */ 1223 1224 /*-------------------------------------------------------------------------*/ 1225 1226 /** 1227 * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue 1228 * @hcd: host controller to which @urb was submitted 1229 * @urb: URB being submitted 1230 * 1231 * Host controller drivers should call this routine in their enqueue() 1232 * method. The HCD's private spinlock must be held and interrupts must 1233 * be disabled. The actions carried out here are required for URB 1234 * submission, as well as for endpoint shutdown and for usb_kill_urb. 1235 * 1236 * Return: 0 for no error, otherwise a negative error code (in which case 1237 * the enqueue() method must fail). If no error occurs but enqueue() fails 1238 * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing 1239 * the private spinlock and returning. 1240 */ 1241 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb) 1242 { 1243 int rc = 0; 1244 1245 spin_lock(&hcd_urb_list_lock); 1246 1247 /* Check that the URB isn't being killed */ 1248 if (unlikely(atomic_read(&urb->reject))) { 1249 rc = -EPERM; 1250 goto done; 1251 } 1252 1253 if (unlikely(!urb->ep->enabled)) { 1254 rc = -ENOENT; 1255 goto done; 1256 } 1257 1258 if (unlikely(!urb->dev->can_submit)) { 1259 rc = -EHOSTUNREACH; 1260 goto done; 1261 } 1262 1263 /* 1264 * Check the host controller's state and add the URB to the 1265 * endpoint's queue. 1266 */ 1267 if (HCD_RH_RUNNING(hcd)) { 1268 urb->unlinked = 0; 1269 list_add_tail(&urb->urb_list, &urb->ep->urb_list); 1270 } else { 1271 rc = -ESHUTDOWN; 1272 goto done; 1273 } 1274 done: 1275 spin_unlock(&hcd_urb_list_lock); 1276 return rc; 1277 } 1278 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep); 1279 1280 /** 1281 * usb_hcd_check_unlink_urb - check whether an URB may be unlinked 1282 * @hcd: host controller to which @urb was submitted 1283 * @urb: URB being checked for unlinkability 1284 * @status: error code to store in @urb if the unlink succeeds 1285 * 1286 * Host controller drivers should call this routine in their dequeue() 1287 * method. The HCD's private spinlock must be held and interrupts must 1288 * be disabled. The actions carried out here are required for making 1289 * sure than an unlink is valid. 1290 * 1291 * Return: 0 for no error, otherwise a negative error code (in which case 1292 * the dequeue() method must fail). The possible error codes are: 1293 * 1294 * -EIDRM: @urb was not submitted or has already completed. 1295 * The completion function may not have been called yet. 1296 * 1297 * -EBUSY: @urb has already been unlinked. 1298 */ 1299 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb, 1300 int status) 1301 { 1302 struct list_head *tmp; 1303 1304 /* insist the urb is still queued */ 1305 list_for_each(tmp, &urb->ep->urb_list) { 1306 if (tmp == &urb->urb_list) 1307 break; 1308 } 1309 if (tmp != &urb->urb_list) 1310 return -EIDRM; 1311 1312 /* Any status except -EINPROGRESS means something already started to 1313 * unlink this URB from the hardware. So there's no more work to do. 1314 */ 1315 if (urb->unlinked) 1316 return -EBUSY; 1317 urb->unlinked = status; 1318 return 0; 1319 } 1320 EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb); 1321 1322 /** 1323 * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue 1324 * @hcd: host controller to which @urb was submitted 1325 * @urb: URB being unlinked 1326 * 1327 * Host controller drivers should call this routine before calling 1328 * usb_hcd_giveback_urb(). The HCD's private spinlock must be held and 1329 * interrupts must be disabled. The actions carried out here are required 1330 * for URB completion. 1331 */ 1332 void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb) 1333 { 1334 /* clear all state linking urb to this dev (and hcd) */ 1335 spin_lock(&hcd_urb_list_lock); 1336 list_del_init(&urb->urb_list); 1337 spin_unlock(&hcd_urb_list_lock); 1338 } 1339 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep); 1340 1341 /* 1342 * Some usb host controllers can only perform dma using a small SRAM area. 1343 * The usb core itself is however optimized for host controllers that can dma 1344 * using regular system memory - like pci devices doing bus mastering. 1345 * 1346 * To support host controllers with limited dma capabilities we provide dma 1347 * bounce buffers. This feature can be enabled using the HCD_LOCAL_MEM flag. 1348 * For this to work properly the host controller code must first use the 1349 * function dma_declare_coherent_memory() to point out which memory area 1350 * that should be used for dma allocations. 1351 * 1352 * The HCD_LOCAL_MEM flag then tells the usb code to allocate all data for 1353 * dma using dma_alloc_coherent() which in turn allocates from the memory 1354 * area pointed out with dma_declare_coherent_memory(). 1355 * 1356 * So, to summarize... 1357 * 1358 * - We need "local" memory, canonical example being 1359 * a small SRAM on a discrete controller being the 1360 * only memory that the controller can read ... 1361 * (a) "normal" kernel memory is no good, and 1362 * (b) there's not enough to share 1363 * 1364 * - The only *portable* hook for such stuff in the 1365 * DMA framework is dma_declare_coherent_memory() 1366 * 1367 * - So we use that, even though the primary requirement 1368 * is that the memory be "local" (hence addressable 1369 * by that device), not "coherent". 1370 * 1371 */ 1372 1373 static int hcd_alloc_coherent(struct usb_bus *bus, 1374 gfp_t mem_flags, dma_addr_t *dma_handle, 1375 void **vaddr_handle, size_t size, 1376 enum dma_data_direction dir) 1377 { 1378 unsigned char *vaddr; 1379 1380 if (*vaddr_handle == NULL) { 1381 WARN_ON_ONCE(1); 1382 return -EFAULT; 1383 } 1384 1385 vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr), 1386 mem_flags, dma_handle); 1387 if (!vaddr) 1388 return -ENOMEM; 1389 1390 /* 1391 * Store the virtual address of the buffer at the end 1392 * of the allocated dma buffer. The size of the buffer 1393 * may be uneven so use unaligned functions instead 1394 * of just rounding up. It makes sense to optimize for 1395 * memory footprint over access speed since the amount 1396 * of memory available for dma may be limited. 1397 */ 1398 put_unaligned((unsigned long)*vaddr_handle, 1399 (unsigned long *)(vaddr + size)); 1400 1401 if (dir == DMA_TO_DEVICE) 1402 memcpy(vaddr, *vaddr_handle, size); 1403 1404 *vaddr_handle = vaddr; 1405 return 0; 1406 } 1407 1408 static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle, 1409 void **vaddr_handle, size_t size, 1410 enum dma_data_direction dir) 1411 { 1412 unsigned char *vaddr = *vaddr_handle; 1413 1414 vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size)); 1415 1416 if (dir == DMA_FROM_DEVICE) 1417 memcpy(vaddr, *vaddr_handle, size); 1418 1419 hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle); 1420 1421 *vaddr_handle = vaddr; 1422 *dma_handle = 0; 1423 } 1424 1425 void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb) 1426 { 1427 if (IS_ENABLED(CONFIG_HAS_DMA) && 1428 (urb->transfer_flags & URB_SETUP_MAP_SINGLE)) 1429 dma_unmap_single(hcd->self.sysdev, 1430 urb->setup_dma, 1431 sizeof(struct usb_ctrlrequest), 1432 DMA_TO_DEVICE); 1433 else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL) 1434 hcd_free_coherent(urb->dev->bus, 1435 &urb->setup_dma, 1436 (void **) &urb->setup_packet, 1437 sizeof(struct usb_ctrlrequest), 1438 DMA_TO_DEVICE); 1439 1440 /* Make it safe to call this routine more than once */ 1441 urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL); 1442 } 1443 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma); 1444 1445 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb) 1446 { 1447 if (hcd->driver->unmap_urb_for_dma) 1448 hcd->driver->unmap_urb_for_dma(hcd, urb); 1449 else 1450 usb_hcd_unmap_urb_for_dma(hcd, urb); 1451 } 1452 1453 void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb) 1454 { 1455 enum dma_data_direction dir; 1456 1457 usb_hcd_unmap_urb_setup_for_dma(hcd, urb); 1458 1459 dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE; 1460 if (IS_ENABLED(CONFIG_HAS_DMA) && 1461 (urb->transfer_flags & URB_DMA_MAP_SG)) 1462 dma_unmap_sg(hcd->self.sysdev, 1463 urb->sg, 1464 urb->num_sgs, 1465 dir); 1466 else if (IS_ENABLED(CONFIG_HAS_DMA) && 1467 (urb->transfer_flags & URB_DMA_MAP_PAGE)) 1468 dma_unmap_page(hcd->self.sysdev, 1469 urb->transfer_dma, 1470 urb->transfer_buffer_length, 1471 dir); 1472 else if (IS_ENABLED(CONFIG_HAS_DMA) && 1473 (urb->transfer_flags & URB_DMA_MAP_SINGLE)) 1474 dma_unmap_single(hcd->self.sysdev, 1475 urb->transfer_dma, 1476 urb->transfer_buffer_length, 1477 dir); 1478 else if (urb->transfer_flags & URB_MAP_LOCAL) 1479 hcd_free_coherent(urb->dev->bus, 1480 &urb->transfer_dma, 1481 &urb->transfer_buffer, 1482 urb->transfer_buffer_length, 1483 dir); 1484 1485 /* Make it safe to call this routine more than once */ 1486 urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE | 1487 URB_DMA_MAP_SINGLE | URB_MAP_LOCAL); 1488 } 1489 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma); 1490 1491 static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, 1492 gfp_t mem_flags) 1493 { 1494 if (hcd->driver->map_urb_for_dma) 1495 return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags); 1496 else 1497 return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags); 1498 } 1499 1500 int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, 1501 gfp_t mem_flags) 1502 { 1503 enum dma_data_direction dir; 1504 int ret = 0; 1505 1506 /* Map the URB's buffers for DMA access. 1507 * Lower level HCD code should use *_dma exclusively, 1508 * unless it uses pio or talks to another transport, 1509 * or uses the provided scatter gather list for bulk. 1510 */ 1511 1512 if (usb_endpoint_xfer_control(&urb->ep->desc)) { 1513 if (hcd->self.uses_pio_for_control) 1514 return ret; 1515 if (IS_ENABLED(CONFIG_HAS_DMA) && hcd->self.uses_dma) { 1516 if (is_vmalloc_addr(urb->setup_packet)) { 1517 WARN_ONCE(1, "setup packet is not dma capable\n"); 1518 return -EAGAIN; 1519 } else if (object_is_on_stack(urb->setup_packet)) { 1520 WARN_ONCE(1, "setup packet is on stack\n"); 1521 return -EAGAIN; 1522 } 1523 1524 urb->setup_dma = dma_map_single( 1525 hcd->self.sysdev, 1526 urb->setup_packet, 1527 sizeof(struct usb_ctrlrequest), 1528 DMA_TO_DEVICE); 1529 if (dma_mapping_error(hcd->self.sysdev, 1530 urb->setup_dma)) 1531 return -EAGAIN; 1532 urb->transfer_flags |= URB_SETUP_MAP_SINGLE; 1533 } else if (hcd->driver->flags & HCD_LOCAL_MEM) { 1534 ret = hcd_alloc_coherent( 1535 urb->dev->bus, mem_flags, 1536 &urb->setup_dma, 1537 (void **)&urb->setup_packet, 1538 sizeof(struct usb_ctrlrequest), 1539 DMA_TO_DEVICE); 1540 if (ret) 1541 return ret; 1542 urb->transfer_flags |= URB_SETUP_MAP_LOCAL; 1543 } 1544 } 1545 1546 dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE; 1547 if (urb->transfer_buffer_length != 0 1548 && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) { 1549 if (IS_ENABLED(CONFIG_HAS_DMA) && hcd->self.uses_dma) { 1550 if (urb->num_sgs) { 1551 int n; 1552 1553 /* We don't support sg for isoc transfers ! */ 1554 if (usb_endpoint_xfer_isoc(&urb->ep->desc)) { 1555 WARN_ON(1); 1556 return -EINVAL; 1557 } 1558 1559 n = dma_map_sg( 1560 hcd->self.sysdev, 1561 urb->sg, 1562 urb->num_sgs, 1563 dir); 1564 if (n <= 0) 1565 ret = -EAGAIN; 1566 else 1567 urb->transfer_flags |= URB_DMA_MAP_SG; 1568 urb->num_mapped_sgs = n; 1569 if (n != urb->num_sgs) 1570 urb->transfer_flags |= 1571 URB_DMA_SG_COMBINED; 1572 } else if (urb->sg) { 1573 struct scatterlist *sg = urb->sg; 1574 urb->transfer_dma = dma_map_page( 1575 hcd->self.sysdev, 1576 sg_page(sg), 1577 sg->offset, 1578 urb->transfer_buffer_length, 1579 dir); 1580 if (dma_mapping_error(hcd->self.sysdev, 1581 urb->transfer_dma)) 1582 ret = -EAGAIN; 1583 else 1584 urb->transfer_flags |= URB_DMA_MAP_PAGE; 1585 } else if (is_vmalloc_addr(urb->transfer_buffer)) { 1586 WARN_ONCE(1, "transfer buffer not dma capable\n"); 1587 ret = -EAGAIN; 1588 } else if (object_is_on_stack(urb->transfer_buffer)) { 1589 WARN_ONCE(1, "transfer buffer is on stack\n"); 1590 ret = -EAGAIN; 1591 } else { 1592 urb->transfer_dma = dma_map_single( 1593 hcd->self.sysdev, 1594 urb->transfer_buffer, 1595 urb->transfer_buffer_length, 1596 dir); 1597 if (dma_mapping_error(hcd->self.sysdev, 1598 urb->transfer_dma)) 1599 ret = -EAGAIN; 1600 else 1601 urb->transfer_flags |= URB_DMA_MAP_SINGLE; 1602 } 1603 } else if (hcd->driver->flags & HCD_LOCAL_MEM) { 1604 ret = hcd_alloc_coherent( 1605 urb->dev->bus, mem_flags, 1606 &urb->transfer_dma, 1607 &urb->transfer_buffer, 1608 urb->transfer_buffer_length, 1609 dir); 1610 if (ret == 0) 1611 urb->transfer_flags |= URB_MAP_LOCAL; 1612 } 1613 if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE | 1614 URB_SETUP_MAP_LOCAL))) 1615 usb_hcd_unmap_urb_for_dma(hcd, urb); 1616 } 1617 return ret; 1618 } 1619 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma); 1620 1621 /*-------------------------------------------------------------------------*/ 1622 1623 /* may be called in any context with a valid urb->dev usecount 1624 * caller surrenders "ownership" of urb 1625 * expects usb_submit_urb() to have sanity checked and conditioned all 1626 * inputs in the urb 1627 */ 1628 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags) 1629 { 1630 int status; 1631 struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus); 1632 1633 /* increment urb's reference count as part of giving it to the HCD 1634 * (which will control it). HCD guarantees that it either returns 1635 * an error or calls giveback(), but not both. 1636 */ 1637 usb_get_urb(urb); 1638 atomic_inc(&urb->use_count); 1639 atomic_inc(&urb->dev->urbnum); 1640 usbmon_urb_submit(&hcd->self, urb); 1641 1642 /* NOTE requirements on root-hub callers (usbfs and the hub 1643 * driver, for now): URBs' urb->transfer_buffer must be 1644 * valid and usb_buffer_{sync,unmap}() not be needed, since 1645 * they could clobber root hub response data. Also, control 1646 * URBs must be submitted in process context with interrupts 1647 * enabled. 1648 */ 1649 1650 if (is_root_hub(urb->dev)) { 1651 status = rh_urb_enqueue(hcd, urb); 1652 } else { 1653 status = map_urb_for_dma(hcd, urb, mem_flags); 1654 if (likely(status == 0)) { 1655 status = hcd->driver->urb_enqueue(hcd, urb, mem_flags); 1656 if (unlikely(status)) 1657 unmap_urb_for_dma(hcd, urb); 1658 } 1659 } 1660 1661 if (unlikely(status)) { 1662 usbmon_urb_submit_error(&hcd->self, urb, status); 1663 urb->hcpriv = NULL; 1664 INIT_LIST_HEAD(&urb->urb_list); 1665 atomic_dec(&urb->use_count); 1666 atomic_dec(&urb->dev->urbnum); 1667 if (atomic_read(&urb->reject)) 1668 wake_up(&usb_kill_urb_queue); 1669 usb_put_urb(urb); 1670 } 1671 return status; 1672 } 1673 1674 /*-------------------------------------------------------------------------*/ 1675 1676 /* this makes the hcd giveback() the urb more quickly, by kicking it 1677 * off hardware queues (which may take a while) and returning it as 1678 * soon as practical. we've already set up the urb's return status, 1679 * but we can't know if the callback completed already. 1680 */ 1681 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status) 1682 { 1683 int value; 1684 1685 if (is_root_hub(urb->dev)) 1686 value = usb_rh_urb_dequeue(hcd, urb, status); 1687 else { 1688 1689 /* The only reason an HCD might fail this call is if 1690 * it has not yet fully queued the urb to begin with. 1691 * Such failures should be harmless. */ 1692 value = hcd->driver->urb_dequeue(hcd, urb, status); 1693 } 1694 return value; 1695 } 1696 1697 /* 1698 * called in any context 1699 * 1700 * caller guarantees urb won't be recycled till both unlink() 1701 * and the urb's completion function return 1702 */ 1703 int usb_hcd_unlink_urb (struct urb *urb, int status) 1704 { 1705 struct usb_hcd *hcd; 1706 struct usb_device *udev = urb->dev; 1707 int retval = -EIDRM; 1708 unsigned long flags; 1709 1710 /* Prevent the device and bus from going away while 1711 * the unlink is carried out. If they are already gone 1712 * then urb->use_count must be 0, since disconnected 1713 * devices can't have any active URBs. 1714 */ 1715 spin_lock_irqsave(&hcd_urb_unlink_lock, flags); 1716 if (atomic_read(&urb->use_count) > 0) { 1717 retval = 0; 1718 usb_get_dev(udev); 1719 } 1720 spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags); 1721 if (retval == 0) { 1722 hcd = bus_to_hcd(urb->dev->bus); 1723 retval = unlink1(hcd, urb, status); 1724 if (retval == 0) 1725 retval = -EINPROGRESS; 1726 else if (retval != -EIDRM && retval != -EBUSY) 1727 dev_dbg(&udev->dev, "hcd_unlink_urb %pK fail %d\n", 1728 urb, retval); 1729 usb_put_dev(udev); 1730 } 1731 return retval; 1732 } 1733 1734 /*-------------------------------------------------------------------------*/ 1735 1736 static void __usb_hcd_giveback_urb(struct urb *urb) 1737 { 1738 struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus); 1739 struct usb_anchor *anchor = urb->anchor; 1740 int status = urb->unlinked; 1741 1742 urb->hcpriv = NULL; 1743 if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) && 1744 urb->actual_length < urb->transfer_buffer_length && 1745 !status)) 1746 status = -EREMOTEIO; 1747 1748 unmap_urb_for_dma(hcd, urb); 1749 usbmon_urb_complete(&hcd->self, urb, status); 1750 usb_anchor_suspend_wakeups(anchor); 1751 usb_unanchor_urb(urb); 1752 if (likely(status == 0)) 1753 usb_led_activity(USB_LED_EVENT_HOST); 1754 1755 /* pass ownership to the completion handler */ 1756 urb->status = status; 1757 urb->complete(urb); 1758 1759 usb_anchor_resume_wakeups(anchor); 1760 atomic_dec(&urb->use_count); 1761 if (unlikely(atomic_read(&urb->reject))) 1762 wake_up(&usb_kill_urb_queue); 1763 usb_put_urb(urb); 1764 } 1765 1766 static void usb_giveback_urb_bh(unsigned long param) 1767 { 1768 struct giveback_urb_bh *bh = (struct giveback_urb_bh *)param; 1769 struct list_head local_list; 1770 1771 spin_lock_irq(&bh->lock); 1772 bh->running = true; 1773 restart: 1774 list_replace_init(&bh->head, &local_list); 1775 spin_unlock_irq(&bh->lock); 1776 1777 while (!list_empty(&local_list)) { 1778 struct urb *urb; 1779 1780 urb = list_entry(local_list.next, struct urb, urb_list); 1781 list_del_init(&urb->urb_list); 1782 bh->completing_ep = urb->ep; 1783 __usb_hcd_giveback_urb(urb); 1784 bh->completing_ep = NULL; 1785 } 1786 1787 /* check if there are new URBs to giveback */ 1788 spin_lock_irq(&bh->lock); 1789 if (!list_empty(&bh->head)) 1790 goto restart; 1791 bh->running = false; 1792 spin_unlock_irq(&bh->lock); 1793 } 1794 1795 /** 1796 * usb_hcd_giveback_urb - return URB from HCD to device driver 1797 * @hcd: host controller returning the URB 1798 * @urb: urb being returned to the USB device driver. 1799 * @status: completion status code for the URB. 1800 * Context: in_interrupt() 1801 * 1802 * This hands the URB from HCD to its USB device driver, using its 1803 * completion function. The HCD has freed all per-urb resources 1804 * (and is done using urb->hcpriv). It also released all HCD locks; 1805 * the device driver won't cause problems if it frees, modifies, 1806 * or resubmits this URB. 1807 * 1808 * If @urb was unlinked, the value of @status will be overridden by 1809 * @urb->unlinked. Erroneous short transfers are detected in case 1810 * the HCD hasn't checked for them. 1811 */ 1812 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status) 1813 { 1814 struct giveback_urb_bh *bh; 1815 bool running, high_prio_bh; 1816 1817 /* pass status to tasklet via unlinked */ 1818 if (likely(!urb->unlinked)) 1819 urb->unlinked = status; 1820 1821 if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) { 1822 __usb_hcd_giveback_urb(urb); 1823 return; 1824 } 1825 1826 if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) { 1827 bh = &hcd->high_prio_bh; 1828 high_prio_bh = true; 1829 } else { 1830 bh = &hcd->low_prio_bh; 1831 high_prio_bh = false; 1832 } 1833 1834 spin_lock(&bh->lock); 1835 list_add_tail(&urb->urb_list, &bh->head); 1836 running = bh->running; 1837 spin_unlock(&bh->lock); 1838 1839 if (running) 1840 ; 1841 else if (high_prio_bh) 1842 tasklet_hi_schedule(&bh->bh); 1843 else 1844 tasklet_schedule(&bh->bh); 1845 } 1846 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb); 1847 1848 /*-------------------------------------------------------------------------*/ 1849 1850 /* Cancel all URBs pending on this endpoint and wait for the endpoint's 1851 * queue to drain completely. The caller must first insure that no more 1852 * URBs can be submitted for this endpoint. 1853 */ 1854 void usb_hcd_flush_endpoint(struct usb_device *udev, 1855 struct usb_host_endpoint *ep) 1856 { 1857 struct usb_hcd *hcd; 1858 struct urb *urb; 1859 1860 if (!ep) 1861 return; 1862 might_sleep(); 1863 hcd = bus_to_hcd(udev->bus); 1864 1865 /* No more submits can occur */ 1866 spin_lock_irq(&hcd_urb_list_lock); 1867 rescan: 1868 list_for_each_entry_reverse(urb, &ep->urb_list, urb_list) { 1869 int is_in; 1870 1871 if (urb->unlinked) 1872 continue; 1873 usb_get_urb (urb); 1874 is_in = usb_urb_dir_in(urb); 1875 spin_unlock(&hcd_urb_list_lock); 1876 1877 /* kick hcd */ 1878 unlink1(hcd, urb, -ESHUTDOWN); 1879 dev_dbg (hcd->self.controller, 1880 "shutdown urb %pK ep%d%s%s\n", 1881 urb, usb_endpoint_num(&ep->desc), 1882 is_in ? "in" : "out", 1883 ({ char *s; 1884 1885 switch (usb_endpoint_type(&ep->desc)) { 1886 case USB_ENDPOINT_XFER_CONTROL: 1887 s = ""; break; 1888 case USB_ENDPOINT_XFER_BULK: 1889 s = "-bulk"; break; 1890 case USB_ENDPOINT_XFER_INT: 1891 s = "-intr"; break; 1892 default: 1893 s = "-iso"; break; 1894 }; 1895 s; 1896 })); 1897 usb_put_urb (urb); 1898 1899 /* list contents may have changed */ 1900 spin_lock(&hcd_urb_list_lock); 1901 goto rescan; 1902 } 1903 spin_unlock_irq(&hcd_urb_list_lock); 1904 1905 /* Wait until the endpoint queue is completely empty */ 1906 while (!list_empty (&ep->urb_list)) { 1907 spin_lock_irq(&hcd_urb_list_lock); 1908 1909 /* The list may have changed while we acquired the spinlock */ 1910 urb = NULL; 1911 if (!list_empty (&ep->urb_list)) { 1912 urb = list_entry (ep->urb_list.prev, struct urb, 1913 urb_list); 1914 usb_get_urb (urb); 1915 } 1916 spin_unlock_irq(&hcd_urb_list_lock); 1917 1918 if (urb) { 1919 usb_kill_urb (urb); 1920 usb_put_urb (urb); 1921 } 1922 } 1923 } 1924 1925 /** 1926 * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds 1927 * the bus bandwidth 1928 * @udev: target &usb_device 1929 * @new_config: new configuration to install 1930 * @cur_alt: the current alternate interface setting 1931 * @new_alt: alternate interface setting that is being installed 1932 * 1933 * To change configurations, pass in the new configuration in new_config, 1934 * and pass NULL for cur_alt and new_alt. 1935 * 1936 * To reset a device's configuration (put the device in the ADDRESSED state), 1937 * pass in NULL for new_config, cur_alt, and new_alt. 1938 * 1939 * To change alternate interface settings, pass in NULL for new_config, 1940 * pass in the current alternate interface setting in cur_alt, 1941 * and pass in the new alternate interface setting in new_alt. 1942 * 1943 * Return: An error if the requested bandwidth change exceeds the 1944 * bus bandwidth or host controller internal resources. 1945 */ 1946 int usb_hcd_alloc_bandwidth(struct usb_device *udev, 1947 struct usb_host_config *new_config, 1948 struct usb_host_interface *cur_alt, 1949 struct usb_host_interface *new_alt) 1950 { 1951 int num_intfs, i, j; 1952 struct usb_host_interface *alt = NULL; 1953 int ret = 0; 1954 struct usb_hcd *hcd; 1955 struct usb_host_endpoint *ep; 1956 1957 hcd = bus_to_hcd(udev->bus); 1958 if (!hcd->driver->check_bandwidth) 1959 return 0; 1960 1961 /* Configuration is being removed - set configuration 0 */ 1962 if (!new_config && !cur_alt) { 1963 for (i = 1; i < 16; ++i) { 1964 ep = udev->ep_out[i]; 1965 if (ep) 1966 hcd->driver->drop_endpoint(hcd, udev, ep); 1967 ep = udev->ep_in[i]; 1968 if (ep) 1969 hcd->driver->drop_endpoint(hcd, udev, ep); 1970 } 1971 hcd->driver->check_bandwidth(hcd, udev); 1972 return 0; 1973 } 1974 /* Check if the HCD says there's enough bandwidth. Enable all endpoints 1975 * each interface's alt setting 0 and ask the HCD to check the bandwidth 1976 * of the bus. There will always be bandwidth for endpoint 0, so it's 1977 * ok to exclude it. 1978 */ 1979 if (new_config) { 1980 num_intfs = new_config->desc.bNumInterfaces; 1981 /* Remove endpoints (except endpoint 0, which is always on the 1982 * schedule) from the old config from the schedule 1983 */ 1984 for (i = 1; i < 16; ++i) { 1985 ep = udev->ep_out[i]; 1986 if (ep) { 1987 ret = hcd->driver->drop_endpoint(hcd, udev, ep); 1988 if (ret < 0) 1989 goto reset; 1990 } 1991 ep = udev->ep_in[i]; 1992 if (ep) { 1993 ret = hcd->driver->drop_endpoint(hcd, udev, ep); 1994 if (ret < 0) 1995 goto reset; 1996 } 1997 } 1998 for (i = 0; i < num_intfs; ++i) { 1999 struct usb_host_interface *first_alt; 2000 int iface_num; 2001 2002 first_alt = &new_config->intf_cache[i]->altsetting[0]; 2003 iface_num = first_alt->desc.bInterfaceNumber; 2004 /* Set up endpoints for alternate interface setting 0 */ 2005 alt = usb_find_alt_setting(new_config, iface_num, 0); 2006 if (!alt) 2007 /* No alt setting 0? Pick the first setting. */ 2008 alt = first_alt; 2009 2010 for (j = 0; j < alt->desc.bNumEndpoints; j++) { 2011 ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]); 2012 if (ret < 0) 2013 goto reset; 2014 } 2015 } 2016 } 2017 if (cur_alt && new_alt) { 2018 struct usb_interface *iface = usb_ifnum_to_if(udev, 2019 cur_alt->desc.bInterfaceNumber); 2020 2021 if (!iface) 2022 return -EINVAL; 2023 if (iface->resetting_device) { 2024 /* 2025 * The USB core just reset the device, so the xHCI host 2026 * and the device will think alt setting 0 is installed. 2027 * However, the USB core will pass in the alternate 2028 * setting installed before the reset as cur_alt. Dig 2029 * out the alternate setting 0 structure, or the first 2030 * alternate setting if a broken device doesn't have alt 2031 * setting 0. 2032 */ 2033 cur_alt = usb_altnum_to_altsetting(iface, 0); 2034 if (!cur_alt) 2035 cur_alt = &iface->altsetting[0]; 2036 } 2037 2038 /* Drop all the endpoints in the current alt setting */ 2039 for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) { 2040 ret = hcd->driver->drop_endpoint(hcd, udev, 2041 &cur_alt->endpoint[i]); 2042 if (ret < 0) 2043 goto reset; 2044 } 2045 /* Add all the endpoints in the new alt setting */ 2046 for (i = 0; i < new_alt->desc.bNumEndpoints; i++) { 2047 ret = hcd->driver->add_endpoint(hcd, udev, 2048 &new_alt->endpoint[i]); 2049 if (ret < 0) 2050 goto reset; 2051 } 2052 } 2053 ret = hcd->driver->check_bandwidth(hcd, udev); 2054 reset: 2055 if (ret < 0) 2056 hcd->driver->reset_bandwidth(hcd, udev); 2057 return ret; 2058 } 2059 2060 /* Disables the endpoint: synchronizes with the hcd to make sure all 2061 * endpoint state is gone from hardware. usb_hcd_flush_endpoint() must 2062 * have been called previously. Use for set_configuration, set_interface, 2063 * driver removal, physical disconnect. 2064 * 2065 * example: a qh stored in ep->hcpriv, holding state related to endpoint 2066 * type, maxpacket size, toggle, halt status, and scheduling. 2067 */ 2068 void usb_hcd_disable_endpoint(struct usb_device *udev, 2069 struct usb_host_endpoint *ep) 2070 { 2071 struct usb_hcd *hcd; 2072 2073 might_sleep(); 2074 hcd = bus_to_hcd(udev->bus); 2075 if (hcd->driver->endpoint_disable) 2076 hcd->driver->endpoint_disable(hcd, ep); 2077 } 2078 2079 /** 2080 * usb_hcd_reset_endpoint - reset host endpoint state 2081 * @udev: USB device. 2082 * @ep: the endpoint to reset. 2083 * 2084 * Resets any host endpoint state such as the toggle bit, sequence 2085 * number and current window. 2086 */ 2087 void usb_hcd_reset_endpoint(struct usb_device *udev, 2088 struct usb_host_endpoint *ep) 2089 { 2090 struct usb_hcd *hcd = bus_to_hcd(udev->bus); 2091 2092 if (hcd->driver->endpoint_reset) 2093 hcd->driver->endpoint_reset(hcd, ep); 2094 else { 2095 int epnum = usb_endpoint_num(&ep->desc); 2096 int is_out = usb_endpoint_dir_out(&ep->desc); 2097 int is_control = usb_endpoint_xfer_control(&ep->desc); 2098 2099 usb_settoggle(udev, epnum, is_out, 0); 2100 if (is_control) 2101 usb_settoggle(udev, epnum, !is_out, 0); 2102 } 2103 } 2104 2105 /** 2106 * usb_alloc_streams - allocate bulk endpoint stream IDs. 2107 * @interface: alternate setting that includes all endpoints. 2108 * @eps: array of endpoints that need streams. 2109 * @num_eps: number of endpoints in the array. 2110 * @num_streams: number of streams to allocate. 2111 * @mem_flags: flags hcd should use to allocate memory. 2112 * 2113 * Sets up a group of bulk endpoints to have @num_streams stream IDs available. 2114 * Drivers may queue multiple transfers to different stream IDs, which may 2115 * complete in a different order than they were queued. 2116 * 2117 * Return: On success, the number of allocated streams. On failure, a negative 2118 * error code. 2119 */ 2120 int usb_alloc_streams(struct usb_interface *interface, 2121 struct usb_host_endpoint **eps, unsigned int num_eps, 2122 unsigned int num_streams, gfp_t mem_flags) 2123 { 2124 struct usb_hcd *hcd; 2125 struct usb_device *dev; 2126 int i, ret; 2127 2128 dev = interface_to_usbdev(interface); 2129 hcd = bus_to_hcd(dev->bus); 2130 if (!hcd->driver->alloc_streams || !hcd->driver->free_streams) 2131 return -EINVAL; 2132 if (dev->speed < USB_SPEED_SUPER) 2133 return -EINVAL; 2134 if (dev->state < USB_STATE_CONFIGURED) 2135 return -ENODEV; 2136 2137 for (i = 0; i < num_eps; i++) { 2138 /* Streams only apply to bulk endpoints. */ 2139 if (!usb_endpoint_xfer_bulk(&eps[i]->desc)) 2140 return -EINVAL; 2141 /* Re-alloc is not allowed */ 2142 if (eps[i]->streams) 2143 return -EINVAL; 2144 } 2145 2146 ret = hcd->driver->alloc_streams(hcd, dev, eps, num_eps, 2147 num_streams, mem_flags); 2148 if (ret < 0) 2149 return ret; 2150 2151 for (i = 0; i < num_eps; i++) 2152 eps[i]->streams = ret; 2153 2154 return ret; 2155 } 2156 EXPORT_SYMBOL_GPL(usb_alloc_streams); 2157 2158 /** 2159 * usb_free_streams - free bulk endpoint stream IDs. 2160 * @interface: alternate setting that includes all endpoints. 2161 * @eps: array of endpoints to remove streams from. 2162 * @num_eps: number of endpoints in the array. 2163 * @mem_flags: flags hcd should use to allocate memory. 2164 * 2165 * Reverts a group of bulk endpoints back to not using stream IDs. 2166 * Can fail if we are given bad arguments, or HCD is broken. 2167 * 2168 * Return: 0 on success. On failure, a negative error code. 2169 */ 2170 int usb_free_streams(struct usb_interface *interface, 2171 struct usb_host_endpoint **eps, unsigned int num_eps, 2172 gfp_t mem_flags) 2173 { 2174 struct usb_hcd *hcd; 2175 struct usb_device *dev; 2176 int i, ret; 2177 2178 dev = interface_to_usbdev(interface); 2179 hcd = bus_to_hcd(dev->bus); 2180 if (dev->speed < USB_SPEED_SUPER) 2181 return -EINVAL; 2182 2183 /* Double-free is not allowed */ 2184 for (i = 0; i < num_eps; i++) 2185 if (!eps[i] || !eps[i]->streams) 2186 return -EINVAL; 2187 2188 ret = hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags); 2189 if (ret < 0) 2190 return ret; 2191 2192 for (i = 0; i < num_eps; i++) 2193 eps[i]->streams = 0; 2194 2195 return ret; 2196 } 2197 EXPORT_SYMBOL_GPL(usb_free_streams); 2198 2199 /* Protect against drivers that try to unlink URBs after the device 2200 * is gone, by waiting until all unlinks for @udev are finished. 2201 * Since we don't currently track URBs by device, simply wait until 2202 * nothing is running in the locked region of usb_hcd_unlink_urb(). 2203 */ 2204 void usb_hcd_synchronize_unlinks(struct usb_device *udev) 2205 { 2206 spin_lock_irq(&hcd_urb_unlink_lock); 2207 spin_unlock_irq(&hcd_urb_unlink_lock); 2208 } 2209 2210 /*-------------------------------------------------------------------------*/ 2211 2212 /* called in any context */ 2213 int usb_hcd_get_frame_number (struct usb_device *udev) 2214 { 2215 struct usb_hcd *hcd = bus_to_hcd(udev->bus); 2216 2217 if (!HCD_RH_RUNNING(hcd)) 2218 return -ESHUTDOWN; 2219 return hcd->driver->get_frame_number (hcd); 2220 } 2221 2222 /*-------------------------------------------------------------------------*/ 2223 2224 #ifdef CONFIG_PM 2225 2226 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg) 2227 { 2228 struct usb_hcd *hcd = bus_to_hcd(rhdev->bus); 2229 int status; 2230 int old_state = hcd->state; 2231 2232 dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n", 2233 (PMSG_IS_AUTO(msg) ? "auto-" : ""), 2234 rhdev->do_remote_wakeup); 2235 if (HCD_DEAD(hcd)) { 2236 dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend"); 2237 return 0; 2238 } 2239 2240 if (!hcd->driver->bus_suspend) { 2241 status = -ENOENT; 2242 } else { 2243 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags); 2244 hcd->state = HC_STATE_QUIESCING; 2245 status = hcd->driver->bus_suspend(hcd); 2246 } 2247 if (status == 0) { 2248 usb_set_device_state(rhdev, USB_STATE_SUSPENDED); 2249 hcd->state = HC_STATE_SUSPENDED; 2250 2251 if (!PMSG_IS_AUTO(msg)) 2252 usb_phy_roothub_suspend(hcd->self.sysdev, 2253 hcd->phy_roothub); 2254 2255 /* Did we race with a root-hub wakeup event? */ 2256 if (rhdev->do_remote_wakeup) { 2257 char buffer[6]; 2258 2259 status = hcd->driver->hub_status_data(hcd, buffer); 2260 if (status != 0) { 2261 dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n"); 2262 hcd_bus_resume(rhdev, PMSG_AUTO_RESUME); 2263 status = -EBUSY; 2264 } 2265 } 2266 } else { 2267 spin_lock_irq(&hcd_root_hub_lock); 2268 if (!HCD_DEAD(hcd)) { 2269 set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags); 2270 hcd->state = old_state; 2271 } 2272 spin_unlock_irq(&hcd_root_hub_lock); 2273 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n", 2274 "suspend", status); 2275 } 2276 return status; 2277 } 2278 2279 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg) 2280 { 2281 struct usb_hcd *hcd = bus_to_hcd(rhdev->bus); 2282 int status; 2283 int old_state = hcd->state; 2284 2285 dev_dbg(&rhdev->dev, "usb %sresume\n", 2286 (PMSG_IS_AUTO(msg) ? "auto-" : "")); 2287 if (HCD_DEAD(hcd)) { 2288 dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume"); 2289 return 0; 2290 } 2291 2292 if (!PMSG_IS_AUTO(msg)) { 2293 status = usb_phy_roothub_resume(hcd->self.sysdev, 2294 hcd->phy_roothub); 2295 if (status) 2296 return status; 2297 } 2298 2299 if (!hcd->driver->bus_resume) 2300 return -ENOENT; 2301 if (HCD_RH_RUNNING(hcd)) 2302 return 0; 2303 2304 hcd->state = HC_STATE_RESUMING; 2305 status = hcd->driver->bus_resume(hcd); 2306 clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags); 2307 if (status == 0) { 2308 struct usb_device *udev; 2309 int port1; 2310 2311 spin_lock_irq(&hcd_root_hub_lock); 2312 if (!HCD_DEAD(hcd)) { 2313 usb_set_device_state(rhdev, rhdev->actconfig 2314 ? USB_STATE_CONFIGURED 2315 : USB_STATE_ADDRESS); 2316 set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags); 2317 hcd->state = HC_STATE_RUNNING; 2318 } 2319 spin_unlock_irq(&hcd_root_hub_lock); 2320 2321 /* 2322 * Check whether any of the enabled ports on the root hub are 2323 * unsuspended. If they are then a TRSMRCY delay is needed 2324 * (this is what the USB-2 spec calls a "global resume"). 2325 * Otherwise we can skip the delay. 2326 */ 2327 usb_hub_for_each_child(rhdev, port1, udev) { 2328 if (udev->state != USB_STATE_NOTATTACHED && 2329 !udev->port_is_suspended) { 2330 usleep_range(10000, 11000); /* TRSMRCY */ 2331 break; 2332 } 2333 } 2334 } else { 2335 hcd->state = old_state; 2336 usb_phy_roothub_suspend(hcd->self.sysdev, hcd->phy_roothub); 2337 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n", 2338 "resume", status); 2339 if (status != -ESHUTDOWN) 2340 usb_hc_died(hcd); 2341 } 2342 return status; 2343 } 2344 2345 /* Workqueue routine for root-hub remote wakeup */ 2346 static void hcd_resume_work(struct work_struct *work) 2347 { 2348 struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work); 2349 struct usb_device *udev = hcd->self.root_hub; 2350 2351 usb_remote_wakeup(udev); 2352 } 2353 2354 /** 2355 * usb_hcd_resume_root_hub - called by HCD to resume its root hub 2356 * @hcd: host controller for this root hub 2357 * 2358 * The USB host controller calls this function when its root hub is 2359 * suspended (with the remote wakeup feature enabled) and a remote 2360 * wakeup request is received. The routine submits a workqueue request 2361 * to resume the root hub (that is, manage its downstream ports again). 2362 */ 2363 void usb_hcd_resume_root_hub (struct usb_hcd *hcd) 2364 { 2365 unsigned long flags; 2366 2367 spin_lock_irqsave (&hcd_root_hub_lock, flags); 2368 if (hcd->rh_registered) { 2369 pm_wakeup_event(&hcd->self.root_hub->dev, 0); 2370 set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags); 2371 queue_work(pm_wq, &hcd->wakeup_work); 2372 } 2373 spin_unlock_irqrestore (&hcd_root_hub_lock, flags); 2374 } 2375 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub); 2376 2377 #endif /* CONFIG_PM */ 2378 2379 /*-------------------------------------------------------------------------*/ 2380 2381 #ifdef CONFIG_USB_OTG 2382 2383 /** 2384 * usb_bus_start_enum - start immediate enumeration (for OTG) 2385 * @bus: the bus (must use hcd framework) 2386 * @port_num: 1-based number of port; usually bus->otg_port 2387 * Context: in_interrupt() 2388 * 2389 * Starts enumeration, with an immediate reset followed later by 2390 * hub_wq identifying and possibly configuring the device. 2391 * This is needed by OTG controller drivers, where it helps meet 2392 * HNP protocol timing requirements for starting a port reset. 2393 * 2394 * Return: 0 if successful. 2395 */ 2396 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num) 2397 { 2398 struct usb_hcd *hcd; 2399 int status = -EOPNOTSUPP; 2400 2401 /* NOTE: since HNP can't start by grabbing the bus's address0_sem, 2402 * boards with root hubs hooked up to internal devices (instead of 2403 * just the OTG port) may need more attention to resetting... 2404 */ 2405 hcd = bus_to_hcd(bus); 2406 if (port_num && hcd->driver->start_port_reset) 2407 status = hcd->driver->start_port_reset(hcd, port_num); 2408 2409 /* allocate hub_wq shortly after (first) root port reset finishes; 2410 * it may issue others, until at least 50 msecs have passed. 2411 */ 2412 if (status == 0) 2413 mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10)); 2414 return status; 2415 } 2416 EXPORT_SYMBOL_GPL(usb_bus_start_enum); 2417 2418 #endif 2419 2420 /*-------------------------------------------------------------------------*/ 2421 2422 /** 2423 * usb_hcd_irq - hook IRQs to HCD framework (bus glue) 2424 * @irq: the IRQ being raised 2425 * @__hcd: pointer to the HCD whose IRQ is being signaled 2426 * 2427 * If the controller isn't HALTed, calls the driver's irq handler. 2428 * Checks whether the controller is now dead. 2429 * 2430 * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise. 2431 */ 2432 irqreturn_t usb_hcd_irq (int irq, void *__hcd) 2433 { 2434 struct usb_hcd *hcd = __hcd; 2435 irqreturn_t rc; 2436 2437 if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd))) 2438 rc = IRQ_NONE; 2439 else if (hcd->driver->irq(hcd) == IRQ_NONE) 2440 rc = IRQ_NONE; 2441 else 2442 rc = IRQ_HANDLED; 2443 2444 return rc; 2445 } 2446 EXPORT_SYMBOL_GPL(usb_hcd_irq); 2447 2448 /*-------------------------------------------------------------------------*/ 2449 2450 /** 2451 * usb_hc_died - report abnormal shutdown of a host controller (bus glue) 2452 * @hcd: pointer to the HCD representing the controller 2453 * 2454 * This is called by bus glue to report a USB host controller that died 2455 * while operations may still have been pending. It's called automatically 2456 * by the PCI glue, so only glue for non-PCI busses should need to call it. 2457 * 2458 * Only call this function with the primary HCD. 2459 */ 2460 void usb_hc_died (struct usb_hcd *hcd) 2461 { 2462 unsigned long flags; 2463 2464 dev_err (hcd->self.controller, "HC died; cleaning up\n"); 2465 2466 spin_lock_irqsave (&hcd_root_hub_lock, flags); 2467 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags); 2468 set_bit(HCD_FLAG_DEAD, &hcd->flags); 2469 if (hcd->rh_registered) { 2470 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags); 2471 2472 /* make hub_wq clean up old urbs and devices */ 2473 usb_set_device_state (hcd->self.root_hub, 2474 USB_STATE_NOTATTACHED); 2475 usb_kick_hub_wq(hcd->self.root_hub); 2476 } 2477 if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) { 2478 hcd = hcd->shared_hcd; 2479 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags); 2480 set_bit(HCD_FLAG_DEAD, &hcd->flags); 2481 if (hcd->rh_registered) { 2482 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags); 2483 2484 /* make hub_wq clean up old urbs and devices */ 2485 usb_set_device_state(hcd->self.root_hub, 2486 USB_STATE_NOTATTACHED); 2487 usb_kick_hub_wq(hcd->self.root_hub); 2488 } 2489 } 2490 spin_unlock_irqrestore (&hcd_root_hub_lock, flags); 2491 /* Make sure that the other roothub is also deallocated. */ 2492 } 2493 EXPORT_SYMBOL_GPL (usb_hc_died); 2494 2495 /*-------------------------------------------------------------------------*/ 2496 2497 static void init_giveback_urb_bh(struct giveback_urb_bh *bh) 2498 { 2499 2500 spin_lock_init(&bh->lock); 2501 INIT_LIST_HEAD(&bh->head); 2502 tasklet_init(&bh->bh, usb_giveback_urb_bh, (unsigned long)bh); 2503 } 2504 2505 struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver, 2506 struct device *sysdev, struct device *dev, const char *bus_name, 2507 struct usb_hcd *primary_hcd) 2508 { 2509 struct usb_hcd *hcd; 2510 2511 hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL); 2512 if (!hcd) 2513 return NULL; 2514 if (primary_hcd == NULL) { 2515 hcd->address0_mutex = kmalloc(sizeof(*hcd->address0_mutex), 2516 GFP_KERNEL); 2517 if (!hcd->address0_mutex) { 2518 kfree(hcd); 2519 dev_dbg(dev, "hcd address0 mutex alloc failed\n"); 2520 return NULL; 2521 } 2522 mutex_init(hcd->address0_mutex); 2523 hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex), 2524 GFP_KERNEL); 2525 if (!hcd->bandwidth_mutex) { 2526 kfree(hcd->address0_mutex); 2527 kfree(hcd); 2528 dev_dbg(dev, "hcd bandwidth mutex alloc failed\n"); 2529 return NULL; 2530 } 2531 mutex_init(hcd->bandwidth_mutex); 2532 dev_set_drvdata(dev, hcd); 2533 } else { 2534 mutex_lock(&usb_port_peer_mutex); 2535 hcd->address0_mutex = primary_hcd->address0_mutex; 2536 hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex; 2537 hcd->primary_hcd = primary_hcd; 2538 primary_hcd->primary_hcd = primary_hcd; 2539 hcd->shared_hcd = primary_hcd; 2540 primary_hcd->shared_hcd = hcd; 2541 mutex_unlock(&usb_port_peer_mutex); 2542 } 2543 2544 kref_init(&hcd->kref); 2545 2546 usb_bus_init(&hcd->self); 2547 hcd->self.controller = dev; 2548 hcd->self.sysdev = sysdev; 2549 hcd->self.bus_name = bus_name; 2550 hcd->self.uses_dma = (sysdev->dma_mask != NULL); 2551 2552 timer_setup(&hcd->rh_timer, rh_timer_func, 0); 2553 #ifdef CONFIG_PM 2554 INIT_WORK(&hcd->wakeup_work, hcd_resume_work); 2555 #endif 2556 2557 hcd->driver = driver; 2558 hcd->speed = driver->flags & HCD_MASK; 2559 hcd->product_desc = (driver->product_desc) ? driver->product_desc : 2560 "USB Host Controller"; 2561 return hcd; 2562 } 2563 EXPORT_SYMBOL_GPL(__usb_create_hcd); 2564 2565 /** 2566 * usb_create_shared_hcd - create and initialize an HCD structure 2567 * @driver: HC driver that will use this hcd 2568 * @dev: device for this HC, stored in hcd->self.controller 2569 * @bus_name: value to store in hcd->self.bus_name 2570 * @primary_hcd: a pointer to the usb_hcd structure that is sharing the 2571 * PCI device. Only allocate certain resources for the primary HCD 2572 * Context: !in_interrupt() 2573 * 2574 * Allocate a struct usb_hcd, with extra space at the end for the 2575 * HC driver's private data. Initialize the generic members of the 2576 * hcd structure. 2577 * 2578 * Return: On success, a pointer to the created and initialized HCD structure. 2579 * On failure (e.g. if memory is unavailable), %NULL. 2580 */ 2581 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver, 2582 struct device *dev, const char *bus_name, 2583 struct usb_hcd *primary_hcd) 2584 { 2585 return __usb_create_hcd(driver, dev, dev, bus_name, primary_hcd); 2586 } 2587 EXPORT_SYMBOL_GPL(usb_create_shared_hcd); 2588 2589 /** 2590 * usb_create_hcd - create and initialize an HCD structure 2591 * @driver: HC driver that will use this hcd 2592 * @dev: device for this HC, stored in hcd->self.controller 2593 * @bus_name: value to store in hcd->self.bus_name 2594 * Context: !in_interrupt() 2595 * 2596 * Allocate a struct usb_hcd, with extra space at the end for the 2597 * HC driver's private data. Initialize the generic members of the 2598 * hcd structure. 2599 * 2600 * Return: On success, a pointer to the created and initialized HCD 2601 * structure. On failure (e.g. if memory is unavailable), %NULL. 2602 */ 2603 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver, 2604 struct device *dev, const char *bus_name) 2605 { 2606 return __usb_create_hcd(driver, dev, dev, bus_name, NULL); 2607 } 2608 EXPORT_SYMBOL_GPL(usb_create_hcd); 2609 2610 /* 2611 * Roothubs that share one PCI device must also share the bandwidth mutex. 2612 * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is 2613 * deallocated. 2614 * 2615 * Make sure to deallocate the bandwidth_mutex only when the last HCD is 2616 * freed. When hcd_release() is called for either hcd in a peer set, 2617 * invalidate the peer's ->shared_hcd and ->primary_hcd pointers. 2618 */ 2619 static void hcd_release(struct kref *kref) 2620 { 2621 struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref); 2622 2623 mutex_lock(&usb_port_peer_mutex); 2624 if (hcd->shared_hcd) { 2625 struct usb_hcd *peer = hcd->shared_hcd; 2626 2627 peer->shared_hcd = NULL; 2628 peer->primary_hcd = NULL; 2629 } else { 2630 kfree(hcd->address0_mutex); 2631 kfree(hcd->bandwidth_mutex); 2632 } 2633 mutex_unlock(&usb_port_peer_mutex); 2634 kfree(hcd); 2635 } 2636 2637 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd) 2638 { 2639 if (hcd) 2640 kref_get (&hcd->kref); 2641 return hcd; 2642 } 2643 EXPORT_SYMBOL_GPL(usb_get_hcd); 2644 2645 void usb_put_hcd (struct usb_hcd *hcd) 2646 { 2647 if (hcd) 2648 kref_put (&hcd->kref, hcd_release); 2649 } 2650 EXPORT_SYMBOL_GPL(usb_put_hcd); 2651 2652 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd) 2653 { 2654 if (!hcd->primary_hcd) 2655 return 1; 2656 return hcd == hcd->primary_hcd; 2657 } 2658 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd); 2659 2660 int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1) 2661 { 2662 if (!hcd->driver->find_raw_port_number) 2663 return port1; 2664 2665 return hcd->driver->find_raw_port_number(hcd, port1); 2666 } 2667 2668 static int usb_hcd_request_irqs(struct usb_hcd *hcd, 2669 unsigned int irqnum, unsigned long irqflags) 2670 { 2671 int retval; 2672 2673 if (hcd->driver->irq) { 2674 2675 snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d", 2676 hcd->driver->description, hcd->self.busnum); 2677 retval = request_irq(irqnum, &usb_hcd_irq, irqflags, 2678 hcd->irq_descr, hcd); 2679 if (retval != 0) { 2680 dev_err(hcd->self.controller, 2681 "request interrupt %d failed\n", 2682 irqnum); 2683 return retval; 2684 } 2685 hcd->irq = irqnum; 2686 dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum, 2687 (hcd->driver->flags & HCD_MEMORY) ? 2688 "io mem" : "io base", 2689 (unsigned long long)hcd->rsrc_start); 2690 } else { 2691 hcd->irq = 0; 2692 if (hcd->rsrc_start) 2693 dev_info(hcd->self.controller, "%s 0x%08llx\n", 2694 (hcd->driver->flags & HCD_MEMORY) ? 2695 "io mem" : "io base", 2696 (unsigned long long)hcd->rsrc_start); 2697 } 2698 return 0; 2699 } 2700 2701 /* 2702 * Before we free this root hub, flush in-flight peering attempts 2703 * and disable peer lookups 2704 */ 2705 static void usb_put_invalidate_rhdev(struct usb_hcd *hcd) 2706 { 2707 struct usb_device *rhdev; 2708 2709 mutex_lock(&usb_port_peer_mutex); 2710 rhdev = hcd->self.root_hub; 2711 hcd->self.root_hub = NULL; 2712 mutex_unlock(&usb_port_peer_mutex); 2713 usb_put_dev(rhdev); 2714 } 2715 2716 /** 2717 * usb_add_hcd - finish generic HCD structure initialization and register 2718 * @hcd: the usb_hcd structure to initialize 2719 * @irqnum: Interrupt line to allocate 2720 * @irqflags: Interrupt type flags 2721 * 2722 * Finish the remaining parts of generic HCD initialization: allocate the 2723 * buffers of consistent memory, register the bus, request the IRQ line, 2724 * and call the driver's reset() and start() routines. 2725 */ 2726 int usb_add_hcd(struct usb_hcd *hcd, 2727 unsigned int irqnum, unsigned long irqflags) 2728 { 2729 int retval; 2730 struct usb_device *rhdev; 2731 2732 if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) { 2733 hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev); 2734 if (IS_ERR(hcd->phy_roothub)) 2735 return PTR_ERR(hcd->phy_roothub); 2736 2737 retval = usb_phy_roothub_init(hcd->phy_roothub); 2738 if (retval) 2739 return retval; 2740 2741 retval = usb_phy_roothub_power_on(hcd->phy_roothub); 2742 if (retval) 2743 goto err_usb_phy_roothub_power_on; 2744 } 2745 2746 dev_info(hcd->self.controller, "%s\n", hcd->product_desc); 2747 2748 /* Keep old behaviour if authorized_default is not in [0, 1]. */ 2749 if (authorized_default < 0 || authorized_default > 1) { 2750 if (hcd->wireless) 2751 clear_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags); 2752 else 2753 set_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags); 2754 } else { 2755 if (authorized_default) 2756 set_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags); 2757 else 2758 clear_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags); 2759 } 2760 set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags); 2761 2762 /* per default all interfaces are authorized */ 2763 set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags); 2764 2765 /* HC is in reset state, but accessible. Now do the one-time init, 2766 * bottom up so that hcds can customize the root hubs before hub_wq 2767 * starts talking to them. (Note, bus id is assigned early too.) 2768 */ 2769 retval = hcd_buffer_create(hcd); 2770 if (retval != 0) { 2771 dev_dbg(hcd->self.sysdev, "pool alloc failed\n"); 2772 goto err_create_buf; 2773 } 2774 2775 retval = usb_register_bus(&hcd->self); 2776 if (retval < 0) 2777 goto err_register_bus; 2778 2779 rhdev = usb_alloc_dev(NULL, &hcd->self, 0); 2780 if (rhdev == NULL) { 2781 dev_err(hcd->self.sysdev, "unable to allocate root hub\n"); 2782 retval = -ENOMEM; 2783 goto err_allocate_root_hub; 2784 } 2785 mutex_lock(&usb_port_peer_mutex); 2786 hcd->self.root_hub = rhdev; 2787 mutex_unlock(&usb_port_peer_mutex); 2788 2789 rhdev->rx_lanes = 1; 2790 rhdev->tx_lanes = 1; 2791 2792 switch (hcd->speed) { 2793 case HCD_USB11: 2794 rhdev->speed = USB_SPEED_FULL; 2795 break; 2796 case HCD_USB2: 2797 rhdev->speed = USB_SPEED_HIGH; 2798 break; 2799 case HCD_USB25: 2800 rhdev->speed = USB_SPEED_WIRELESS; 2801 break; 2802 case HCD_USB3: 2803 rhdev->speed = USB_SPEED_SUPER; 2804 break; 2805 case HCD_USB32: 2806 rhdev->rx_lanes = 2; 2807 rhdev->tx_lanes = 2; 2808 /* fall through */ 2809 case HCD_USB31: 2810 rhdev->speed = USB_SPEED_SUPER_PLUS; 2811 break; 2812 default: 2813 retval = -EINVAL; 2814 goto err_set_rh_speed; 2815 } 2816 2817 /* wakeup flag init defaults to "everything works" for root hubs, 2818 * but drivers can override it in reset() if needed, along with 2819 * recording the overall controller's system wakeup capability. 2820 */ 2821 device_set_wakeup_capable(&rhdev->dev, 1); 2822 2823 /* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is 2824 * registered. But since the controller can die at any time, 2825 * let's initialize the flag before touching the hardware. 2826 */ 2827 set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags); 2828 2829 /* "reset" is misnamed; its role is now one-time init. the controller 2830 * should already have been reset (and boot firmware kicked off etc). 2831 */ 2832 if (hcd->driver->reset) { 2833 retval = hcd->driver->reset(hcd); 2834 if (retval < 0) { 2835 dev_err(hcd->self.controller, "can't setup: %d\n", 2836 retval); 2837 goto err_hcd_driver_setup; 2838 } 2839 } 2840 hcd->rh_pollable = 1; 2841 2842 /* NOTE: root hub and controller capabilities may not be the same */ 2843 if (device_can_wakeup(hcd->self.controller) 2844 && device_can_wakeup(&hcd->self.root_hub->dev)) 2845 dev_dbg(hcd->self.controller, "supports USB remote wakeup\n"); 2846 2847 /* initialize tasklets */ 2848 init_giveback_urb_bh(&hcd->high_prio_bh); 2849 init_giveback_urb_bh(&hcd->low_prio_bh); 2850 2851 /* enable irqs just before we start the controller, 2852 * if the BIOS provides legacy PCI irqs. 2853 */ 2854 if (usb_hcd_is_primary_hcd(hcd) && irqnum) { 2855 retval = usb_hcd_request_irqs(hcd, irqnum, irqflags); 2856 if (retval) 2857 goto err_request_irq; 2858 } 2859 2860 hcd->state = HC_STATE_RUNNING; 2861 retval = hcd->driver->start(hcd); 2862 if (retval < 0) { 2863 dev_err(hcd->self.controller, "startup error %d\n", retval); 2864 goto err_hcd_driver_start; 2865 } 2866 2867 /* starting here, usbcore will pay attention to this root hub */ 2868 retval = register_root_hub(hcd); 2869 if (retval != 0) 2870 goto err_register_root_hub; 2871 2872 retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group); 2873 if (retval < 0) { 2874 printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n", 2875 retval); 2876 goto error_create_attr_group; 2877 } 2878 if (hcd->uses_new_polling && HCD_POLL_RH(hcd)) 2879 usb_hcd_poll_rh_status(hcd); 2880 2881 return retval; 2882 2883 error_create_attr_group: 2884 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags); 2885 if (HC_IS_RUNNING(hcd->state)) 2886 hcd->state = HC_STATE_QUIESCING; 2887 spin_lock_irq(&hcd_root_hub_lock); 2888 hcd->rh_registered = 0; 2889 spin_unlock_irq(&hcd_root_hub_lock); 2890 2891 #ifdef CONFIG_PM 2892 cancel_work_sync(&hcd->wakeup_work); 2893 #endif 2894 mutex_lock(&usb_bus_idr_lock); 2895 usb_disconnect(&rhdev); /* Sets rhdev to NULL */ 2896 mutex_unlock(&usb_bus_idr_lock); 2897 err_register_root_hub: 2898 hcd->rh_pollable = 0; 2899 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags); 2900 del_timer_sync(&hcd->rh_timer); 2901 hcd->driver->stop(hcd); 2902 hcd->state = HC_STATE_HALT; 2903 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags); 2904 del_timer_sync(&hcd->rh_timer); 2905 err_hcd_driver_start: 2906 if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0) 2907 free_irq(irqnum, hcd); 2908 err_request_irq: 2909 err_hcd_driver_setup: 2910 err_set_rh_speed: 2911 usb_put_invalidate_rhdev(hcd); 2912 err_allocate_root_hub: 2913 usb_deregister_bus(&hcd->self); 2914 err_register_bus: 2915 hcd_buffer_destroy(hcd); 2916 err_create_buf: 2917 usb_phy_roothub_power_off(hcd->phy_roothub); 2918 err_usb_phy_roothub_power_on: 2919 usb_phy_roothub_exit(hcd->phy_roothub); 2920 2921 return retval; 2922 } 2923 EXPORT_SYMBOL_GPL(usb_add_hcd); 2924 2925 /** 2926 * usb_remove_hcd - shutdown processing for generic HCDs 2927 * @hcd: the usb_hcd structure to remove 2928 * Context: !in_interrupt() 2929 * 2930 * Disconnects the root hub, then reverses the effects of usb_add_hcd(), 2931 * invoking the HCD's stop() method. 2932 */ 2933 void usb_remove_hcd(struct usb_hcd *hcd) 2934 { 2935 struct usb_device *rhdev = hcd->self.root_hub; 2936 2937 dev_info(hcd->self.controller, "remove, state %x\n", hcd->state); 2938 2939 usb_get_dev(rhdev); 2940 sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group); 2941 2942 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags); 2943 if (HC_IS_RUNNING (hcd->state)) 2944 hcd->state = HC_STATE_QUIESCING; 2945 2946 dev_dbg(hcd->self.controller, "roothub graceful disconnect\n"); 2947 spin_lock_irq (&hcd_root_hub_lock); 2948 hcd->rh_registered = 0; 2949 spin_unlock_irq (&hcd_root_hub_lock); 2950 2951 #ifdef CONFIG_PM 2952 cancel_work_sync(&hcd->wakeup_work); 2953 #endif 2954 2955 mutex_lock(&usb_bus_idr_lock); 2956 usb_disconnect(&rhdev); /* Sets rhdev to NULL */ 2957 mutex_unlock(&usb_bus_idr_lock); 2958 2959 /* 2960 * tasklet_kill() isn't needed here because: 2961 * - driver's disconnect() called from usb_disconnect() should 2962 * make sure its URBs are completed during the disconnect() 2963 * callback 2964 * 2965 * - it is too late to run complete() here since driver may have 2966 * been removed already now 2967 */ 2968 2969 /* Prevent any more root-hub status calls from the timer. 2970 * The HCD might still restart the timer (if a port status change 2971 * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke 2972 * the hub_status_data() callback. 2973 */ 2974 hcd->rh_pollable = 0; 2975 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags); 2976 del_timer_sync(&hcd->rh_timer); 2977 2978 hcd->driver->stop(hcd); 2979 hcd->state = HC_STATE_HALT; 2980 2981 /* In case the HCD restarted the timer, stop it again. */ 2982 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags); 2983 del_timer_sync(&hcd->rh_timer); 2984 2985 if (usb_hcd_is_primary_hcd(hcd)) { 2986 if (hcd->irq > 0) 2987 free_irq(hcd->irq, hcd); 2988 } 2989 2990 usb_deregister_bus(&hcd->self); 2991 hcd_buffer_destroy(hcd); 2992 2993 usb_phy_roothub_power_off(hcd->phy_roothub); 2994 usb_phy_roothub_exit(hcd->phy_roothub); 2995 2996 usb_put_invalidate_rhdev(hcd); 2997 hcd->flags = 0; 2998 } 2999 EXPORT_SYMBOL_GPL(usb_remove_hcd); 3000 3001 void 3002 usb_hcd_platform_shutdown(struct platform_device *dev) 3003 { 3004 struct usb_hcd *hcd = platform_get_drvdata(dev); 3005 3006 if (hcd->driver->shutdown) 3007 hcd->driver->shutdown(hcd); 3008 } 3009 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown); 3010 3011 /*-------------------------------------------------------------------------*/ 3012 3013 #if IS_ENABLED(CONFIG_USB_MON) 3014 3015 const struct usb_mon_operations *mon_ops; 3016 3017 /* 3018 * The registration is unlocked. 3019 * We do it this way because we do not want to lock in hot paths. 3020 * 3021 * Notice that the code is minimally error-proof. Because usbmon needs 3022 * symbols from usbcore, usbcore gets referenced and cannot be unloaded first. 3023 */ 3024 3025 int usb_mon_register(const struct usb_mon_operations *ops) 3026 { 3027 3028 if (mon_ops) 3029 return -EBUSY; 3030 3031 mon_ops = ops; 3032 mb(); 3033 return 0; 3034 } 3035 EXPORT_SYMBOL_GPL (usb_mon_register); 3036 3037 void usb_mon_deregister (void) 3038 { 3039 3040 if (mon_ops == NULL) { 3041 printk(KERN_ERR "USB: monitor was not registered\n"); 3042 return; 3043 } 3044 mon_ops = NULL; 3045 mb(); 3046 } 3047 EXPORT_SYMBOL_GPL (usb_mon_deregister); 3048 3049 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */ 3050