Greg Kroah-Hartman | 5fd54ac | 2017-11-03 11:28:30 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 2 | /* |
| 3 | * WUSB Wire Adapter: Control/Data Streaming Interface (WUSB[8]) |
| 4 | * Notification EndPoint support |
| 5 | * |
| 6 | * Copyright (C) 2006 Intel Corporation |
| 7 | * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> |
| 8 | * |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 9 | * This part takes care of getting the notification from the hw |
| 10 | * only and dispatching through wusbwad into |
| 11 | * wa_notif_dispatch. Handling is done there. |
| 12 | * |
| 13 | * WA notifications are limited in size; most of them are three or |
| 14 | * four bytes long, and the longest is the HWA Device Notification, |
| 15 | * which would not exceed 38 bytes (DNs are limited in payload to 32 |
| 16 | * bytes plus 3 bytes header (WUSB1.0[7.6p2]), plus 3 bytes HWA |
| 17 | * header (WUSB1.0[8.5.4.2]). |
| 18 | * |
| 19 | * It is not clear if more than one Device Notification can be packed |
| 20 | * in a HWA Notification, I assume no because of the wording in |
| 21 | * WUSB1.0[8.5.4.2]. In any case, the bigger any notification could |
| 22 | * get is 256 bytes (as the bLength field is a byte). |
| 23 | * |
| 24 | * So what we do is we have this buffer and read into it; when a |
| 25 | * notification arrives we schedule work to a specific, single thread |
| 26 | * workqueue (so notifications are serialized) and copy the |
| 27 | * notification data. After scheduling the work, we rearm the read from |
| 28 | * the notification endpoint. |
| 29 | * |
| 30 | * Entry points here are: |
| 31 | * |
| 32 | * wa_nep_[create|destroy]() To initialize/release this subsystem |
| 33 | * |
| 34 | * wa_nep_cb() Callback for the notification |
| 35 | * endpoint; when data is ready, this |
| 36 | * does the dispatching. |
| 37 | */ |
| 38 | #include <linux/workqueue.h> |
| 39 | #include <linux/ctype.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 40 | #include <linux/slab.h> |
David Vrabel | e43ace8 | 2008-12-22 18:27:17 +0000 | [diff] [blame] | 41 | |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 42 | #include "wa-hc.h" |
| 43 | #include "wusbhc.h" |
| 44 | |
| 45 | /* Structure for queueing notifications to the workqueue */ |
| 46 | struct wa_notif_work { |
| 47 | struct work_struct work; |
| 48 | struct wahc *wa; |
| 49 | size_t size; |
| 50 | u8 data[]; |
| 51 | }; |
| 52 | |
| 53 | /* |
| 54 | * Process incoming notifications from the WA's Notification EndPoint |
| 55 | * [the wuswad daemon, basically] |
| 56 | * |
| 57 | * @_nw: Pointer to a descriptor which has the pointer to the |
Rahul Bedarkar | 2627cb0 | 2014-01-04 14:11:01 +0530 | [diff] [blame] | 58 | * @wa, the size of the buffer and the work queue |
| 59 | * structure (so we can free all when done). |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 60 | * @returns 0 if ok, < 0 errno code on error. |
| 61 | * |
| 62 | * All notifications follow the same format; they need to start with a |
| 63 | * 'struct wa_notif_hdr' header, so it is easy to parse through |
| 64 | * them. We just break the buffer in individual notifications (the |
| 65 | * standard doesn't say if it can be done or is forbidden, so we are |
| 66 | * cautious) and dispatch each. |
| 67 | * |
| 68 | * So the handling layers are is: |
| 69 | * |
| 70 | * WA specific notification (from NEP) |
| 71 | * Device Notification Received -> wa_handle_notif_dn() |
| 72 | * WUSB Device notification generic handling |
| 73 | * BPST Adjustment -> wa_handle_notif_bpst_adj() |
| 74 | * ... -> ... |
| 75 | * |
| 76 | * @wa has to be referenced |
| 77 | */ |
| 78 | static void wa_notif_dispatch(struct work_struct *ws) |
| 79 | { |
| 80 | void *itr; |
| 81 | u8 missing = 0; |
Rahul Bedarkar | 2627cb0 | 2014-01-04 14:11:01 +0530 | [diff] [blame] | 82 | struct wa_notif_work *nw = container_of(ws, struct wa_notif_work, |
| 83 | work); |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 84 | struct wahc *wa = nw->wa; |
| 85 | struct wa_notif_hdr *notif_hdr; |
| 86 | size_t size; |
| 87 | |
| 88 | struct device *dev = &wa->usb_iface->dev; |
| 89 | |
| 90 | #if 0 |
| 91 | /* FIXME: need to check for this??? */ |
| 92 | if (usb_hcd->state == HC_STATE_QUIESCING) /* Going down? */ |
| 93 | goto out; /* screw it */ |
| 94 | #endif |
| 95 | atomic_dec(&wa->notifs_queued); /* Throttling ctl */ |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 96 | size = nw->size; |
| 97 | itr = nw->data; |
| 98 | |
| 99 | while (size) { |
| 100 | if (size < sizeof(*notif_hdr)) { |
| 101 | missing = sizeof(*notif_hdr) - size; |
| 102 | goto exhausted_buffer; |
| 103 | } |
| 104 | notif_hdr = itr; |
| 105 | if (size < notif_hdr->bLength) |
| 106 | goto exhausted_buffer; |
| 107 | itr += notif_hdr->bLength; |
| 108 | size -= notif_hdr->bLength; |
| 109 | /* Dispatch the notification [don't use itr or size!] */ |
| 110 | switch (notif_hdr->bNotifyType) { |
| 111 | case HWA_NOTIF_DN: { |
| 112 | struct hwa_notif_dn *hwa_dn; |
| 113 | hwa_dn = container_of(notif_hdr, struct hwa_notif_dn, |
| 114 | hdr); |
| 115 | wusbhc_handle_dn(wa->wusb, hwa_dn->bSourceDeviceAddr, |
| 116 | hwa_dn->dndata, |
| 117 | notif_hdr->bLength - sizeof(*hwa_dn)); |
| 118 | break; |
| 119 | } |
| 120 | case WA_NOTIF_TRANSFER: |
| 121 | wa_handle_notif_xfer(wa, notif_hdr); |
| 122 | break; |
Thomas Pugliese | 3a57aa8 | 2013-06-06 14:39:23 -0500 | [diff] [blame] | 123 | case HWA_NOTIF_BPST_ADJ: |
| 124 | break; /* no action needed for BPST ADJ. */ |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 125 | case DWA_NOTIF_RWAKE: |
| 126 | case DWA_NOTIF_PORTSTATUS: |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 127 | /* FIXME: unimplemented WA NOTIFs */ |
| 128 | /* fallthru */ |
| 129 | default: |
David Vrabel | e43ace8 | 2008-12-22 18:27:17 +0000 | [diff] [blame] | 130 | dev_err(dev, "HWA: unknown notification 0x%x, " |
| 131 | "%zu bytes; discarding\n", |
| 132 | notif_hdr->bNotifyType, |
| 133 | (size_t)notif_hdr->bLength); |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 134 | break; |
| 135 | } |
| 136 | } |
| 137 | out: |
| 138 | wa_put(wa); |
| 139 | kfree(nw); |
| 140 | return; |
| 141 | |
| 142 | /* THIS SHOULD NOT HAPPEN |
| 143 | * |
| 144 | * Buffer exahusted with partial data remaining; just warn and |
| 145 | * discard the data, as this should not happen. |
| 146 | */ |
| 147 | exhausted_buffer: |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 148 | dev_warn(dev, "HWA: device sent short notification, " |
| 149 | "%d bytes missing; discarding %d bytes.\n", |
| 150 | missing, (int)size); |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 151 | goto out; |
| 152 | } |
| 153 | |
| 154 | /* |
| 155 | * Deliver incoming WA notifications to the wusbwa workqueue |
| 156 | * |
| 157 | * @wa: Pointer the Wire Adapter Controller Data Streaming |
| 158 | * instance (part of an 'struct usb_hcd'). |
| 159 | * @size: Size of the received buffer |
| 160 | * @returns 0 if ok, < 0 errno code on error. |
| 161 | * |
| 162 | * The input buffer is @wa->nep_buffer, with @size bytes |
| 163 | * (guaranteed to fit in the allocated space, |
| 164 | * @wa->nep_buffer_size). |
| 165 | */ |
| 166 | static int wa_nep_queue(struct wahc *wa, size_t size) |
| 167 | { |
| 168 | int result = 0; |
| 169 | struct device *dev = &wa->usb_iface->dev; |
| 170 | struct wa_notif_work *nw; |
| 171 | |
| 172 | /* dev_fnstart(dev, "(wa %p, size %zu)\n", wa, size); */ |
| 173 | BUG_ON(size > wa->nep_buffer_size); |
| 174 | if (size == 0) |
| 175 | goto out; |
| 176 | if (atomic_read(&wa->notifs_queued) > 200) { |
| 177 | if (printk_ratelimit()) |
| 178 | dev_err(dev, "Too many notifications queued, " |
| 179 | "throttling back\n"); |
| 180 | goto out; |
| 181 | } |
| 182 | nw = kzalloc(sizeof(*nw) + size, GFP_ATOMIC); |
| 183 | if (nw == NULL) { |
| 184 | if (printk_ratelimit()) |
| 185 | dev_err(dev, "No memory to queue notification\n"); |
Pan Bian | 7faf44b | 2016-11-29 20:56:10 +0800 | [diff] [blame] | 186 | result = -ENOMEM; |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 187 | goto out; |
| 188 | } |
| 189 | INIT_WORK(&nw->work, wa_notif_dispatch); |
| 190 | nw->wa = wa_get(wa); |
| 191 | nw->size = size; |
| 192 | memcpy(nw->data, wa->nep_buffer, size); |
| 193 | atomic_inc(&wa->notifs_queued); /* Throttling ctl */ |
| 194 | queue_work(wusbd, &nw->work); |
| 195 | out: |
| 196 | /* dev_fnend(dev, "(wa %p, size %zu) = result\n", wa, size, result); */ |
| 197 | return result; |
| 198 | } |
| 199 | |
| 200 | /* |
| 201 | * Callback for the notification event endpoint |
| 202 | * |
| 203 | * Check's that everything is fine and then passes the data to be |
| 204 | * queued to the workqueue. |
| 205 | */ |
| 206 | static void wa_nep_cb(struct urb *urb) |
| 207 | { |
| 208 | int result; |
| 209 | struct wahc *wa = urb->context; |
| 210 | struct device *dev = &wa->usb_iface->dev; |
| 211 | |
| 212 | switch (result = urb->status) { |
| 213 | case 0: |
| 214 | result = wa_nep_queue(wa, urb->actual_length); |
| 215 | if (result < 0) |
| 216 | dev_err(dev, "NEP: unable to process notification(s): " |
| 217 | "%d\n", result); |
| 218 | break; |
| 219 | case -ECONNRESET: /* Not an error, but a controlled situation; */ |
| 220 | case -ENOENT: /* (we killed the URB)...so, no broadcast */ |
| 221 | case -ESHUTDOWN: |
| 222 | dev_dbg(dev, "NEP: going down %d\n", urb->status); |
| 223 | goto out; |
| 224 | default: /* On general errors, we retry unless it gets ugly */ |
| 225 | if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS, |
| 226 | EDC_ERROR_TIMEFRAME)) { |
| 227 | dev_err(dev, "NEP: URB max acceptable errors " |
| 228 | "exceeded, resetting device\n"); |
| 229 | wa_reset_all(wa); |
| 230 | goto out; |
| 231 | } |
| 232 | dev_err(dev, "NEP: URB error %d\n", urb->status); |
| 233 | } |
| 234 | result = wa_nep_arm(wa, GFP_ATOMIC); |
| 235 | if (result < 0) { |
| 236 | dev_err(dev, "NEP: cannot submit URB: %d\n", result); |
| 237 | wa_reset_all(wa); |
| 238 | } |
| 239 | out: |
| 240 | return; |
| 241 | } |
| 242 | |
| 243 | /* |
| 244 | * Initialize @wa's notification and event's endpoint stuff |
| 245 | * |
| 246 | * This includes the allocating the read buffer, the context ID |
| 247 | * allocation bitmap, the URB and submitting the URB. |
| 248 | */ |
| 249 | int wa_nep_create(struct wahc *wa, struct usb_interface *iface) |
| 250 | { |
| 251 | int result; |
| 252 | struct usb_endpoint_descriptor *epd; |
| 253 | struct usb_device *usb_dev = interface_to_usbdev(iface); |
| 254 | struct device *dev = &iface->dev; |
| 255 | |
| 256 | edc_init(&wa->nep_edc); |
| 257 | epd = &iface->cur_altsetting->endpoint[0].desc; |
| 258 | wa->nep_buffer_size = 1024; |
| 259 | wa->nep_buffer = kmalloc(wa->nep_buffer_size, GFP_KERNEL); |
Wolfram Sang | 84f11ce | 2016-08-25 19:39:36 +0200 | [diff] [blame] | 260 | if (!wa->nep_buffer) |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 261 | goto error_nep_buffer; |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 262 | wa->nep_urb = usb_alloc_urb(0, GFP_KERNEL); |
Wolfram Sang | 6b017b7 | 2016-08-11 23:14:49 +0200 | [diff] [blame] | 263 | if (wa->nep_urb == NULL) |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 264 | goto error_urb_alloc; |
Inaky Perez-Gonzalez | df36542 | 2008-09-17 16:34:29 +0100 | [diff] [blame] | 265 | usb_fill_int_urb(wa->nep_urb, usb_dev, |
| 266 | usb_rcvintpipe(usb_dev, epd->bEndpointAddress), |
| 267 | wa->nep_buffer, wa->nep_buffer_size, |
| 268 | wa_nep_cb, wa, epd->bInterval); |
| 269 | result = wa_nep_arm(wa, GFP_KERNEL); |
| 270 | if (result < 0) { |
| 271 | dev_err(dev, "Cannot submit notification URB: %d\n", result); |
| 272 | goto error_nep_arm; |
| 273 | } |
| 274 | return 0; |
| 275 | |
| 276 | error_nep_arm: |
| 277 | usb_free_urb(wa->nep_urb); |
| 278 | error_urb_alloc: |
| 279 | kfree(wa->nep_buffer); |
| 280 | error_nep_buffer: |
| 281 | return -ENOMEM; |
| 282 | } |
| 283 | |
| 284 | void wa_nep_destroy(struct wahc *wa) |
| 285 | { |
| 286 | wa_nep_disarm(wa); |
| 287 | usb_free_urb(wa->nep_urb); |
| 288 | kfree(wa->nep_buffer); |
| 289 | } |