Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 1 | /* |
| 2 | * libusual |
| 3 | * |
| 4 | * The libusual contains the table of devices common for ub and usb-storage. |
| 5 | */ |
| 6 | #include <linux/kernel.h> |
| 7 | #include <linux/module.h> |
| 8 | #include <linux/usb.h> |
| 9 | #include <linux/usb_usual.h> |
| 10 | #include <linux/vmalloc.h> |
Matthew Dharm | 0e3c8c2 | 2006-08-31 13:37:29 -0700 | [diff] [blame] | 11 | #include <linux/kthread.h> |
Daniel Walker | 75c43b6 | 2008-02-04 23:57:42 -0800 | [diff] [blame] | 12 | #include <linux/mutex.h> |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 13 | |
| 14 | /* |
| 15 | */ |
| 16 | #define USU_MOD_FL_THREAD 1 /* Thread is running */ |
| 17 | #define USU_MOD_FL_PRESENT 2 /* The module is loaded */ |
| 18 | |
| 19 | struct mod_status { |
| 20 | unsigned long fls; |
| 21 | }; |
| 22 | |
| 23 | static struct mod_status stat[3]; |
| 24 | static DEFINE_SPINLOCK(usu_lock); |
| 25 | |
| 26 | /* |
| 27 | */ |
| 28 | #define USB_US_DEFAULT_BIAS USB_US_TYPE_STOR |
Pete Zaitcev | 5ba35bd | 2005-12-16 00:39:36 -0800 | [diff] [blame] | 29 | static atomic_t usu_bias = ATOMIC_INIT(USB_US_DEFAULT_BIAS); |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 30 | |
| 31 | #define BIAS_NAME_SIZE (sizeof("usb-storage")) |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 32 | static const char *bias_names[3] = { "none", "usb-storage", "ub" }; |
| 33 | |
Daniel Walker | 75c43b6 | 2008-02-04 23:57:42 -0800 | [diff] [blame] | 34 | static DEFINE_MUTEX(usu_probe_mutex); |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 35 | static DECLARE_COMPLETION(usu_end_notify); |
| 36 | static atomic_t total_threads = ATOMIC_INIT(0); |
| 37 | |
| 38 | static int usu_probe_thread(void *arg); |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 39 | |
| 40 | /* |
| 41 | * The table. |
| 42 | */ |
| 43 | #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \ |
| 44 | vendorName, productName,useProtocol, useTransport, \ |
| 45 | initFunction, flags) \ |
| 46 | { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin,bcdDeviceMax), \ |
| 47 | .driver_info = (flags)|(USB_US_TYPE_STOR<<24) } |
| 48 | |
Alan Stern | 25ff1c3 | 2008-12-15 12:43:41 -0500 | [diff] [blame] | 49 | #define COMPLIANT_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \ |
| 50 | vendorName, productName, useProtocol, useTransport, \ |
| 51 | initFunction, flags) \ |
| 52 | { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \ |
| 53 | .driver_info = (flags) } |
| 54 | |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 55 | #define USUAL_DEV(useProto, useTrans, useType) \ |
| 56 | { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, useProto, useTrans), \ |
| 57 | .driver_info = ((useType)<<24) } |
| 58 | |
| 59 | struct usb_device_id storage_usb_ids [] = { |
| 60 | # include "unusual_devs.h" |
| 61 | { } /* Terminating entry */ |
| 62 | }; |
| 63 | |
| 64 | #undef USUAL_DEV |
| 65 | #undef UNUSUAL_DEV |
Alan Stern | 25ff1c3 | 2008-12-15 12:43:41 -0500 | [diff] [blame] | 66 | #undef COMPLIANT_DEV |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 67 | |
| 68 | MODULE_DEVICE_TABLE(usb, storage_usb_ids); |
| 69 | EXPORT_SYMBOL_GPL(storage_usb_ids); |
| 70 | |
| 71 | /* |
| 72 | * @type: the module type as an integer |
| 73 | */ |
| 74 | void usb_usual_set_present(int type) |
| 75 | { |
| 76 | struct mod_status *st; |
| 77 | unsigned long flags; |
| 78 | |
| 79 | if (type <= 0 || type >= 3) |
| 80 | return; |
| 81 | st = &stat[type]; |
| 82 | spin_lock_irqsave(&usu_lock, flags); |
| 83 | st->fls |= USU_MOD_FL_PRESENT; |
| 84 | spin_unlock_irqrestore(&usu_lock, flags); |
| 85 | } |
| 86 | EXPORT_SYMBOL_GPL(usb_usual_set_present); |
| 87 | |
| 88 | void usb_usual_clear_present(int type) |
| 89 | { |
| 90 | struct mod_status *st; |
| 91 | unsigned long flags; |
| 92 | |
| 93 | if (type <= 0 || type >= 3) |
| 94 | return; |
| 95 | st = &stat[type]; |
| 96 | spin_lock_irqsave(&usu_lock, flags); |
| 97 | st->fls &= ~USU_MOD_FL_PRESENT; |
| 98 | spin_unlock_irqrestore(&usu_lock, flags); |
| 99 | } |
| 100 | EXPORT_SYMBOL_GPL(usb_usual_clear_present); |
| 101 | |
| 102 | /* |
| 103 | * Match the calling driver type against the table. |
| 104 | * Returns: 0 if the device matches. |
| 105 | */ |
| 106 | int usb_usual_check_type(const struct usb_device_id *id, int caller_type) |
| 107 | { |
| 108 | int id_type = USB_US_TYPE(id->driver_info); |
| 109 | |
| 110 | if (caller_type <= 0 || caller_type >= 3) |
| 111 | return -EINVAL; |
| 112 | |
| 113 | /* Drivers grab fixed assignment devices */ |
| 114 | if (id_type == caller_type) |
| 115 | return 0; |
| 116 | /* Drivers grab devices biased to them */ |
Pete Zaitcev | 5ba35bd | 2005-12-16 00:39:36 -0800 | [diff] [blame] | 117 | if (id_type == USB_US_TYPE_NONE && caller_type == atomic_read(&usu_bias)) |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 118 | return 0; |
| 119 | return -ENODEV; |
| 120 | } |
| 121 | EXPORT_SYMBOL_GPL(usb_usual_check_type); |
| 122 | |
| 123 | /* |
| 124 | */ |
| 125 | static int usu_probe(struct usb_interface *intf, |
| 126 | const struct usb_device_id *id) |
| 127 | { |
Pete Zaitcev | 64e35d9 | 2007-03-08 20:02:26 -0800 | [diff] [blame] | 128 | int rc; |
Alan Cox | 6d453b9 | 2006-01-17 15:39:25 -0800 | [diff] [blame] | 129 | unsigned long type; |
Matthew Dharm | 0e3c8c2 | 2006-08-31 13:37:29 -0700 | [diff] [blame] | 130 | struct task_struct* task; |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 131 | unsigned long flags; |
| 132 | |
| 133 | type = USB_US_TYPE(id->driver_info); |
| 134 | if (type == 0) |
Pete Zaitcev | 5ba35bd | 2005-12-16 00:39:36 -0800 | [diff] [blame] | 135 | type = atomic_read(&usu_bias); |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 136 | |
| 137 | spin_lock_irqsave(&usu_lock, flags); |
| 138 | if ((stat[type].fls & (USU_MOD_FL_THREAD|USU_MOD_FL_PRESENT)) != 0) { |
| 139 | spin_unlock_irqrestore(&usu_lock, flags); |
| 140 | return -ENXIO; |
| 141 | } |
| 142 | stat[type].fls |= USU_MOD_FL_THREAD; |
| 143 | spin_unlock_irqrestore(&usu_lock, flags); |
| 144 | |
Rusty Russell | 0430421 | 2008-04-21 06:38:34 +1000 | [diff] [blame] | 145 | task = kthread_run(usu_probe_thread, (void*)type, "libusual_%ld", type); |
Matthew Dharm | 0e3c8c2 | 2006-08-31 13:37:29 -0700 | [diff] [blame] | 146 | if (IS_ERR(task)) { |
Pete Zaitcev | 64e35d9 | 2007-03-08 20:02:26 -0800 | [diff] [blame] | 147 | rc = PTR_ERR(task); |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 148 | printk(KERN_WARNING "libusual: " |
| 149 | "Unable to start the thread for %s: %d\n", |
| 150 | bias_names[type], rc); |
| 151 | spin_lock_irqsave(&usu_lock, flags); |
| 152 | stat[type].fls &= ~USU_MOD_FL_THREAD; |
| 153 | spin_unlock_irqrestore(&usu_lock, flags); |
| 154 | return rc; /* Not being -ENXIO causes a message printed */ |
| 155 | } |
| 156 | atomic_inc(&total_threads); |
| 157 | |
| 158 | return -ENXIO; |
| 159 | } |
| 160 | |
| 161 | static void usu_disconnect(struct usb_interface *intf) |
| 162 | { |
| 163 | ; /* We should not be here. */ |
| 164 | } |
| 165 | |
| 166 | static struct usb_driver usu_driver = { |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 167 | .name = "libusual", |
| 168 | .probe = usu_probe, |
| 169 | .disconnect = usu_disconnect, |
| 170 | .id_table = storage_usb_ids, |
| 171 | }; |
| 172 | |
| 173 | /* |
| 174 | * A whole new thread for a purpose of request_module seems quite stupid. |
| 175 | * The request_module forks once inside again. However, if we attempt |
| 176 | * to load a storage module from our own modprobe thread, that module |
| 177 | * references our symbols, which cannot be resolved until our module is |
| 178 | * initialized. I wish there was a way to wait for the end of initialization. |
| 179 | * The module notifier reports MODULE_STATE_COMING only. |
| 180 | * So, we wait until module->init ends as the next best thing. |
| 181 | */ |
| 182 | static int usu_probe_thread(void *arg) |
| 183 | { |
| 184 | int type = (unsigned long) arg; |
| 185 | struct mod_status *st = &stat[type]; |
| 186 | int rc; |
| 187 | unsigned long flags; |
| 188 | |
Daniel Walker | 75c43b6 | 2008-02-04 23:57:42 -0800 | [diff] [blame] | 189 | mutex_lock(&usu_probe_mutex); |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 190 | rc = request_module(bias_names[type]); |
| 191 | spin_lock_irqsave(&usu_lock, flags); |
| 192 | if (rc == 0 && (st->fls & USU_MOD_FL_PRESENT) == 0) { |
| 193 | /* |
| 194 | * This should not happen, but let us keep tabs on it. |
| 195 | */ |
| 196 | printk(KERN_NOTICE "libusual: " |
| 197 | "modprobe for %s succeeded, but module is not present\n", |
| 198 | bias_names[type]); |
| 199 | } |
| 200 | st->fls &= ~USU_MOD_FL_THREAD; |
| 201 | spin_unlock_irqrestore(&usu_lock, flags); |
Daniel Walker | 75c43b6 | 2008-02-04 23:57:42 -0800 | [diff] [blame] | 202 | mutex_unlock(&usu_probe_mutex); |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 203 | |
| 204 | complete_and_exit(&usu_end_notify, 0); |
| 205 | } |
| 206 | |
| 207 | /* |
| 208 | */ |
| 209 | static int __init usb_usual_init(void) |
| 210 | { |
| 211 | int rc; |
| 212 | |
Daniel Walker | 75c43b6 | 2008-02-04 23:57:42 -0800 | [diff] [blame] | 213 | mutex_lock(&usu_probe_mutex); |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 214 | rc = usb_register(&usu_driver); |
Daniel Walker | 75c43b6 | 2008-02-04 23:57:42 -0800 | [diff] [blame] | 215 | mutex_unlock(&usu_probe_mutex); |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 216 | return rc; |
| 217 | } |
| 218 | |
| 219 | static void __exit usb_usual_exit(void) |
| 220 | { |
| 221 | /* |
| 222 | * We do not check for any drivers present, because |
| 223 | * they keep us pinned with symbol references. |
| 224 | */ |
| 225 | |
| 226 | usb_deregister(&usu_driver); |
| 227 | |
| 228 | while (atomic_read(&total_threads) > 0) { |
| 229 | wait_for_completion(&usu_end_notify); |
| 230 | atomic_dec(&total_threads); |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | /* |
| 235 | * Validate and accept the bias parameter. |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 236 | */ |
Pete Zaitcev | 5ba35bd | 2005-12-16 00:39:36 -0800 | [diff] [blame] | 237 | static int usu_set_bias(const char *bias_s, struct kernel_param *kp) |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 238 | { |
| 239 | int i; |
Pete Zaitcev | 5ba35bd | 2005-12-16 00:39:36 -0800 | [diff] [blame] | 240 | int len; |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 241 | int bias_n = 0; |
| 242 | |
Pete Zaitcev | 5ba35bd | 2005-12-16 00:39:36 -0800 | [diff] [blame] | 243 | len = strlen(bias_s); |
| 244 | if (len == 0) |
| 245 | return -EDOM; |
| 246 | if (bias_s[len-1] == '\n') |
| 247 | --len; |
| 248 | |
| 249 | for (i = 1; i < 3; i++) { |
| 250 | if (strncmp(bias_s, bias_names[i], len) == 0) { |
| 251 | bias_n = i; |
| 252 | break; |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 253 | } |
| 254 | } |
Pete Zaitcev | 5ba35bd | 2005-12-16 00:39:36 -0800 | [diff] [blame] | 255 | if (bias_n == 0) |
| 256 | return -EINVAL; |
| 257 | |
| 258 | atomic_set(&usu_bias, bias_n); |
| 259 | return 0; |
| 260 | } |
| 261 | |
| 262 | static int usu_get_bias(char *buffer, struct kernel_param *kp) |
| 263 | { |
| 264 | return strlen(strcpy(buffer, bias_names[atomic_read(&usu_bias)])); |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 265 | } |
| 266 | |
| 267 | module_init(usb_usual_init); |
| 268 | module_exit(usb_usual_exit); |
| 269 | |
Pete Zaitcev | 5ba35bd | 2005-12-16 00:39:36 -0800 | [diff] [blame] | 270 | module_param_call(bias, usu_set_bias, usu_get_bias, NULL, S_IRUGO|S_IWUSR); |
| 271 | __MODULE_PARM_TYPE(bias, "string"); |
Pete Zaitcev | a00828e | 2005-10-22 20:15:09 -0700 | [diff] [blame] | 272 | MODULE_PARM_DESC(bias, "Bias to usb-storage or ub"); |
| 273 | |
| 274 | MODULE_LICENSE("GPL"); |