1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (C) 2021 - 2022 Intel Corporation
4 */
5
6 #ifndef __iwl_mei_h__
7 #define __iwl_mei_h__
8
9 #include <linux/if_ether.h>
10 #include <linux/skbuff.h>
11 #include <linux/ieee80211.h>
12
13 /**
14 * DOC: Introduction
15 *
16 * iwlmei is the kernel module that is in charge of the communication between
17 * the iwlwifi driver and the CSME firmware's WLAN driver. This communication
18 * uses the SAP protocol defined in another file.
19 * iwlwifi can request or release ownership on the WiFi device through iwlmei.
20 * iwlmei may notify iwlwifi about certain events: what filter iwlwifi should
21 * use to passthrough inbound packets to the CSME firmware for example. iwlmei
22 * may also use iwlwifi to send traffic. This means that we need communication
23 * from iwlmei to iwlwifi and the other way around.
24 */
25
26 /**
27 * DOC: Life cycle
28 *
29 * iwlmei exports symbols that are needed by iwlwifi so that iwlmei will always
30 * be loaded when iwlwifi is alive. iwlwifi registers itself to iwlmei and
31 * provides the pointers to the functions that iwlmei calls whenever needed.
32 * iwlwifi calls iwlmei through direct and context-free function calls.
33 * It is assumed that only one device is accessible to the CSME firmware and
34 * under the scope of iwlmei so that it is valid not to have any context passed
35 * to iwlmei's functions.
36 *
37 * There are cases in which iwlmei can't access the CSME firmware, because the
38 * CSME firmware is undergoing a reset, or the mei bus decided to unbind the
39 * device. In those cases, iwlmei will need not to send requests over the mei
40 * bus. Instead, it needs to cache the requests from iwlwifi and fulfill them
41 * when the mei bus is available again.
42 *
43 * iwlmei can call iwlwifi as long as iwlwifi is registered to iwlmei. When
44 * iwlwifi goes down (the PCI device is unbound, or the iwlwifi is unloaded)
45 * iwlwifi needs to unregister from iwlmei.
46 */
47
48 /**
49 * DOC: Memory layout
50 *
51 * Since iwlwifi calls iwlmei without any context, iwlmei needs to hold a
52 * global pointer to its data (which is in the mei client device's private
53 * data area). If there was no bind on the mei bus, this pointer is NULL and
54 * iwlmei knows not access to the CSME firmware upon requests from iwlwifi.
55 *
56 * iwlmei needs to cache requests from iwlwifi when there is no mei client
57 * device available (when iwlmei has been removed from the mei bus). In this
58 * case, all iwlmei's data that resides in the mei client device's private data
59 * area is unavailable. For this specific case, a separate caching area is
60 * needed.
61 */
62
63 /**
64 * DOC: Concurrency
65 *
66 * iwlwifi can call iwlmei at any time. iwlmei will take care to synchronize
67 * the calls from iwlwifi with its internal flows. iwlwifi must not call iwlmei
68 * in flows that cannot sleep. Moreover, iwlwifi must not call iwlmei in flows
69 * that originated from iwlmei.
70 */
71
72 /**
73 * DOC: Probe and remove from mei bus driver
74 *
75 * When the mei bus driver enumerates its devices, it calls the iwlmei's probe
76 * function which will send the %SAP_ME_MSG_START message. The probe completes
77 * before the response (%SAP_ME_MSG_START_OK) is received. This response will
78 * be handle by the Rx path. Once it arrives, the connection to the CSME
79 * firmware is considered established and iwlwifi's requests can be treated
80 * against the CSME firmware.
81 *
82 * When the mei bus driver removes the device, iwlmei loses all the data that
83 * was attached to the mei client device. It clears the global pointer to the
84 * mei client device since it is not available anymore. This will cause all the
85 * requests coming from iwlwifi to be cached. This flow takes the global mutex
86 * to be synchronized with all the requests coming from iwlwifi.
87 */
88
89 /**
90 * DOC: Driver load when CSME owns the device
91 *
92 * When the driver (iwlwifi) is loaded while CSME owns the device,
93 * it'll ask CSME to release the device through HW registers. CSME
94 * will release the device only in the case that there is no connection
95 * through the mei bus. If there is a mei bus connection, CSME will refuse
96 * to release the ownership on the device through the HW registers. In that
97 * case, iwlwifi must first request ownership using the SAP protocol.
98 *
99 * Once iwlwifi will request ownership through the SAP protocol, CSME will
100 * grant the ownership on the device through the HW registers as well.
101 * In order to request ownership over SAP, we first need to have an interface
102 * which means that we need to register to mac80211.
103 * This can't happen before we get the NVM that contains all the capabilities
104 * of the device. Reading the NVM usually requires the load the firmware, but
105 * this is impossible as long as we don't have ownership on the device.
106 * In order to solve this chicken and egg problem, the host driver can get
107 * the NVM through CSME which owns the device. It can send
108 * %SAP_MSG_NOTIF_GET_NVM, which will be replied by %SAP_MSG_NOTIF_NVM with
109 * the NVM's content that the host driver needs.
110 */
111
112 /**
113 * DOC: CSME behavior regarding the ownership requests
114 *
115 * The ownership requests from the host can come in two different ways:
116 * - the HW registers in iwl_pcie_set_hw_ready
117 * - using the Software Arbitration Protocol (SAP)
118 *
119 * The host can ask CSME who owns the device with %SAP_MSG_NOTIF_WHO_OWNS_NIC,
120 * and it can request ownership with %SAP_MSG_NOTIF_HOST_ASKS_FOR_NIC_OWNERSHIP.
121 * The host will first use %SAP_MSG_NOTIF_WHO_OWNS_NIC to know what state
122 * CSME is in. In case CSME thinks it owns the device, the host can ask for
123 * ownership with %SAP_MSG_NOTIF_HOST_ASKS_FOR_NIC_OWNERSHIP.
124 *
125 * Here the table that describes CSME's behavior upon ownership request:
126 *
127 * +-------------------+------------+--------------+-----------------------------+------------+
128 * | State | HW reg bit | Reply for | Event | HW reg bit |
129 * | | before | WHO_OWNS_NIC | | after |
130 * +===================+============+==============+=============================+============+
131 * | WiAMT not | 0 | Host | HW register or | 0 |
132 * | operational | Host owner | | HOST_ASKS_FOR_NIC_OWNERSHIP | Host owner |
133 * +-------------------+------------+--------------+-----------------------------+------------+
134 * | Operational & | 1 | N/A | HW register | 0 |
135 * | SAP down & | CSME owner | | | Host owner |
136 * | no session active | | | | |
137 * +-------------------+------------+--------------+-----------------------------+------------+
138 * | Operational & | 1 | CSME | HW register | 1 |
139 * | SAP up | CSME owner | | | CSME owner |
140 * +-------------------+------------+--------------+-----------------------------+------------+
141 * | Operational & | 1 | CSME | HOST_ASKS_FOR_NIC_OWNERSHIP | 0 |
142 * | SAP up | CSME owner | | | Host owner |
143 * +-------------------+------------+--------------+-----------------------------+------------+
144 */
145
146 /**
147 * DOC: Driver load when CSME is associated and a session is active
148 *
149 * A "session" is active when CSME is associated to an access point and the
150 * link is used to attach a remote driver or to control the system remotely.
151 * When a session is active, we want to make sure it won't disconnect when we
152 * take ownership on the device.
153 * In this case, the driver can get the device, but it'll need to make
154 * sure that it'll connect to the exact same AP (same BSSID).
155 * In order to do so, CSME will send the connection parameters through
156 * SAP and then the host can check if it can connect to this same AP.
157 * If yes, it can request ownership through SAP and connect quickly without
158 * scanning all the channels, but just probing the AP on the channel that
159 * CSME was connected to.
160 * In order to signal this specific scenario to iwlwifi, iwlmei will
161 * immediately require iwlwifi to report RF-Kill to the network stack. This
162 * RF-Kill will prevent the stack from getting the device, and it has a reason
163 * that tells the userspace that the device is in RF-Kill because it is not
164 * owned by the host. Once the userspace has configured the right profile,
165 * it'll be able to let iwlmei know that it can request ownership over SAP
166 * which will remove the RF-Kill, and finally allow the host to connect.
167 * The host has then 3 seconds to connect (including DHCP). Had the host
168 * failed to connect within those 3 seconds, CSME will take the device back.
169 */
170
171 /**
172 * DOC: Datapath
173 *
174 * CSME can transmit packets, through the netdev that it gets from the wifi
175 * driver. It'll send packet in the 802.3 format and simply call
176 * dev_queue_xmit.
177 *
178 * For Rx, iwlmei registers a Rx handler that it attaches to the netdev. iwlmei
179 * may catch packets and send them to CSME, it can then either drop them so
180 * that they are invisible to user space, or let them go the user space.
181 *
182 * Packets transmitted by the user space do not need to be forwarded to CSME
183 * with the exception of the DHCP request. In order to know what IP is used
184 * by the user space, CSME needs to get the DHCP request. See
185 * iwl_mei_tx_copy_to_csme().
186 */
187
188 /**
189 * enum iwl_mei_nvm_caps - capabilities for MEI NVM
190 * @MEI_NVM_CAPS_LARI_SUPPORT: Lari is supported
191 * @MEI_NVM_CAPS_11AX_SUPPORT: 11AX is supported
192 */
193 enum iwl_mei_nvm_caps {
194 MEI_NVM_CAPS_LARI_SUPPORT = BIT(0),
195 MEI_NVM_CAPS_11AX_SUPPORT = BIT(1),
196 };
197
198 /**
199 * struct iwl_mei_nvm - used to pass the NVM from CSME
200 * @hw_addr: The MAC address
201 * @n_hw_addrs: The number of MAC addresses
202 * @reserved: For alignment.
203 * @radio_cfg: The radio configuration.
204 * @caps: See &enum iwl_mei_nvm_caps.
205 * @nvm_version: The version of the NVM.
206 * @channels: The data for each channel.
207 *
208 * If a field is added, it must correspond to the SAP structure.
209 */
210 struct iwl_mei_nvm {
211 u8 hw_addr[ETH_ALEN];
212 u8 n_hw_addrs;
213 u8 reserved;
214 u32 radio_cfg;
215 u32 caps;
216 u32 nvm_version;
217 u32 channels[110];
218 };
219
220 /**
221 * enum iwl_mei_pairwise_cipher - cipher for UCAST key
222 * @IWL_MEI_CIPHER_NONE: none
223 * @IWL_MEI_CIPHER_TKIP: tkip
224 * @IWL_MEI_CIPHER_CCMP: ccmp
225 * @IWL_MEI_CIPHER_GCMP: gcmp
226 * @IWL_MEI_CIPHER_GCMP_256: gcmp 256
227 *
228 * Note that those values are dictated by the CSME firmware API (see sap.h)
229 */
230 enum iwl_mei_pairwise_cipher {
231 IWL_MEI_CIPHER_NONE = 0,
232 IWL_MEI_CIPHER_TKIP = 2,
233 IWL_MEI_CIPHER_CCMP = 4,
234 IWL_MEI_CIPHER_GCMP = 8,
235 IWL_MEI_CIPHER_GCMP_256 = 9,
236 };
237
238 /**
239 * enum iwl_mei_akm_auth - a combination of AKM and AUTH method
240 * @IWL_MEI_AKM_AUTH_OPEN: No encryption
241 * @IWL_MEI_AKM_AUTH_RSNA: 1X profile
242 * @IWL_MEI_AKM_AUTH_RSNA_PSK: PSK profile
243 * @IWL_MEI_AKM_AUTH_SAE: SAE profile
244 *
245 * Note that those values are dictated by the CSME firmware API (see sap.h)
246 */
247 enum iwl_mei_akm_auth {
248 IWL_MEI_AKM_AUTH_OPEN = 0,
249 IWL_MEI_AKM_AUTH_RSNA = 6,
250 IWL_MEI_AKM_AUTH_RSNA_PSK = 7,
251 IWL_MEI_AKM_AUTH_SAE = 9,
252 };
253
254 /**
255 * struct iwl_mei_conn_info - connection info
256 * @lp_state: link protection state
257 * @auth_mode: authentication mode
258 * @ssid_len: the length of SSID
259 * @ssid: the SSID
260 * @pairwise_cipher: the cipher used for unicast packets
261 * @channel: the associated channel
262 * @band: the associated band
263 * @bssid: the BSSID
264 */
265 struct iwl_mei_conn_info {
266 u8 lp_state;
267 u8 auth_mode;
268 u8 ssid_len;
269 u8 channel;
270 u8 band;
271 u8 pairwise_cipher;
272 u8 bssid[ETH_ALEN];
273 u8 ssid[IEEE80211_MAX_SSID_LEN];
274 };
275
276 /**
277 * struct iwl_mei_colloc_info - collocated AP info
278 * @channel: the channel of the collocated AP
279 * @bssid: the BSSID of the collocated AP
280 */
281 struct iwl_mei_colloc_info {
282 u8 channel;
283 u8 bssid[ETH_ALEN];
284 };
285
286 /*
287 * struct iwl_mei_ops - driver's operations called by iwlmei
288 * Operations will not be called more than once concurrently.
289 * It's not allowed to call iwlmei functions from this context.
290 *
291 * @me_conn_status: provide information about CSME's current connection.
292 * @rfkill: called when the wifi driver should report a change in the rfkill
293 * status.
294 * @roaming_forbidden: indicates whether roaming is forbidden.
295 * @sap_connected: indicate that SAP is now connected. Will be called in case
296 * the wifi driver registered to iwlmei before SAP connection succeeded or
297 * when the SAP connection is re-established.
298 * @nic_stolen: this means that device is no longer available. The device can
299 * still be used until the callback returns.
300 */
301 struct iwl_mei_ops {
302 void (*me_conn_status)(void *priv,
303 const struct iwl_mei_conn_info *conn_info);
304 void (*rfkill)(void *priv, bool blocked, bool csme_taking_ownership);
305 void (*roaming_forbidden)(void *priv, bool forbidden);
306 void (*sap_connected)(void *priv);
307 void (*nic_stolen)(void *priv);
308 };
309
310 #if IS_ENABLED(CONFIG_IWLMEI)
311
312 /**
313 * iwl_mei_is_connected() - is the connection to the CSME firmware established?
314 *
315 * Return: true if we have a SAP connection
316 */
317 bool iwl_mei_is_connected(void);
318
319 /**
320 * iwl_mei_get_nvm() - returns the NVM for the device
321 *
322 * It is the caller's responsibility to free the memory returned
323 * by this function.
324 * This function blocks (sleeps) until the NVM is ready.
325 *
326 * Return: the NVM as received from CSME
327 */
328 struct iwl_mei_nvm *iwl_mei_get_nvm(void);
329
330 /**
331 * iwl_mei_get_ownership() - request ownership
332 *
333 * This function blocks until ownership is granted or timeout expired.
334 *
335 * Return: 0 in case we could get ownership on the device
336 */
337 int iwl_mei_get_ownership(void);
338
339 /**
340 * iwl_mei_set_rfkill_state() - set SW and HW RF kill states
341 * @hw_rfkill: HW RF kill state.
342 * @sw_rfkill: SW RF kill state.
343 *
344 * This function must be called when SW RF kill is issued by the user.
345 */
346 void iwl_mei_set_rfkill_state(bool hw_rfkill, bool sw_rfkill);
347
348 /**
349 * iwl_mei_set_nic_info() - set mac address
350 * @mac_address: mac address to set
351 * @nvm_address: NVM mac address to set
352 *
353 * This function must be called upon mac address change.
354 */
355 void iwl_mei_set_nic_info(const u8 *mac_address, const u8 *nvm_address);
356
357 /**
358 * iwl_mei_set_country_code() - set new country code
359 * @mcc: the new applied MCC
360 *
361 * This function must be called upon country code update
362 */
363 void iwl_mei_set_country_code(u16 mcc);
364
365 /**
366 * iwl_mei_set_power_limit() - set TX power limit
367 * @power_limit: pointer to an array of 10 elements (le16) represents the power
368 * restrictions per chain.
369 *
370 * This function must be called upon power restrictions change
371 */
372 void iwl_mei_set_power_limit(const __le16 *power_limit);
373
374 /**
375 * iwl_mei_register() - register the wifi driver to iwlmei
376 * @priv: a pointer to the wifi driver's context. Cannot be NULL.
377 * @ops: the ops structure.
378 *
379 * Return: 0 unless something went wrong. It is illegal to call any
380 * other API function before this function is called and succeeds.
381 *
382 * Only one wifi driver instance (wifi device instance really)
383 * can register at a time.
384 */
385 int iwl_mei_register(void *priv, const struct iwl_mei_ops *ops);
386
387 /**
388 * iwl_mei_start_unregister() - unregister the wifi driver from iwlmei
389 *
390 * From this point on, iwlmei will not used the callbacks provided by
391 * the driver, but the device is still usable.
392 */
393 void iwl_mei_start_unregister(void);
394
395 /**
396 * iwl_mei_unregister_complete() - complete the unregistration
397 *
398 * Must be called after iwl_mei_start_unregister. When this function returns,
399 * the device is owned by CSME.
400 */
401 void iwl_mei_unregister_complete(void);
402
403 /**
404 * iwl_mei_set_netdev() - sets the netdev for Tx / Rx.
405 * @netdev: the net_device
406 *
407 * The caller should set the netdev to a non-NULL value when the
408 * interface is added. Packets might be sent to the driver immediately
409 * afterwards.
410 * The caller should set the netdev to NULL when the interface is removed.
411 * This function will call synchronize_net() after setting the netdev to NULL.
412 * Only when this function returns, can the caller assume that iwlmei will
413 * no longer inject packets into the netdev's Tx path.
414 *
415 * Context: This function can sleep and assumes rtnl_lock is taken.
416 * The netdev must be set to NULL before iwl_mei_start_unregister() is called.
417 */
418 void iwl_mei_set_netdev(struct net_device *netdev);
419
420 /**
421 * iwl_mei_tx_copy_to_csme() - must be called for each packet sent by
422 * the wifi driver.
423 * @skb: the skb sent
424 * @ivlen: the size of the IV that needs to be skipped after the MAC and
425 * before the SNAP header.
426 *
427 * This function doesn't take any lock, it simply tries to catch DHCP
428 * packets sent by the wifi driver. If the packet is a DHCP packet, it
429 * will send it to CSME. This function must not be called for virtual
430 * interfaces that are not monitored by CSME, meaning it must be called
431 * only for packets transmitted by the netdevice that was registered
432 * with iwl_mei_set_netdev().
433 */
434 void iwl_mei_tx_copy_to_csme(struct sk_buff *skb, unsigned int ivlen);
435
436 /**
437 * iwl_mei_host_associated() - must be called when iwlwifi associated.
438 * @conn_info: pointer to the connection info structure.
439 * @colloc_info: pointer to the collocated AP info. This is relevant only in
440 * case of UHB associated AP, otherwise set to NULL.
441 */
442 void iwl_mei_host_associated(const struct iwl_mei_conn_info *conn_info,
443 const struct iwl_mei_colloc_info *colloc_info);
444
445 /**
446 * iwl_mei_host_disassociated() - must be called when iwlwifi disassociated.
447 */
448 void iwl_mei_host_disassociated(void);
449
450 /**
451 * iwl_mei_device_state() - must be called when the device changes up/down state
452 * @up: true if the device is up, false otherwise.
453 */
454 void iwl_mei_device_state(bool up);
455
456 /**
457 * iwl_mei_pldr_req() - must be called before loading the fw
458 *
459 * Return: 0 if the PLDR flow was successful and the fw can be loaded, negative
460 * value otherwise.
461 */
462 int iwl_mei_pldr_req(void);
463
464 /**
465 * iwl_mei_alive_notif() - must be called when alive notificaiton is received
466 * @success: true if received alive notification, false if waiting for the
467 * notificaiton timed out.
468 */
469 void iwl_mei_alive_notif(bool success);
470
471 #else
472
iwl_mei_is_connected(void)473 static inline bool iwl_mei_is_connected(void)
474 { return false; }
475
iwl_mei_get_nvm(void)476 static inline struct iwl_mei_nvm *iwl_mei_get_nvm(void)
477 { return NULL; }
478
iwl_mei_get_ownership(void)479 static inline int iwl_mei_get_ownership(void)
480 { return 0; }
481
iwl_mei_set_rfkill_state(bool hw_rfkill,bool sw_rfkill)482 static inline void iwl_mei_set_rfkill_state(bool hw_rfkill, bool sw_rfkill)
483 {}
484
iwl_mei_set_nic_info(const u8 * mac_address,const u8 * nvm_address)485 static inline void iwl_mei_set_nic_info(const u8 *mac_address, const u8 *nvm_address)
486 {}
487
iwl_mei_set_country_code(u16 mcc)488 static inline void iwl_mei_set_country_code(u16 mcc)
489 {}
490
iwl_mei_set_power_limit(__le16 * power_limit)491 static inline void iwl_mei_set_power_limit(__le16 *power_limit)
492 {}
493
iwl_mei_register(void * priv,const struct iwl_mei_ops * ops)494 static inline int iwl_mei_register(void *priv,
495 const struct iwl_mei_ops *ops)
496 { return 0; }
497
iwl_mei_start_unregister(void)498 static inline void iwl_mei_start_unregister(void)
499 {}
500
iwl_mei_unregister_complete(void)501 static inline void iwl_mei_unregister_complete(void)
502 {}
503
iwl_mei_set_netdev(struct net_device * netdev)504 static inline void iwl_mei_set_netdev(struct net_device *netdev)
505 {}
506
iwl_mei_tx_copy_to_csme(struct sk_buff * skb,unsigned int ivlen)507 static inline void iwl_mei_tx_copy_to_csme(struct sk_buff *skb,
508 unsigned int ivlen)
509 {}
510
iwl_mei_host_associated(const struct iwl_mei_conn_info * conn_info,const struct iwl_mei_colloc_info * colloc_info)511 static inline void iwl_mei_host_associated(const struct iwl_mei_conn_info *conn_info,
512 const struct iwl_mei_colloc_info *colloc_info)
513 {}
514
iwl_mei_host_disassociated(void)515 static inline void iwl_mei_host_disassociated(void)
516 {}
517
iwl_mei_device_state(bool up)518 static inline void iwl_mei_device_state(bool up)
519 {}
520
iwl_mei_pldr_req(void)521 static inline int iwl_mei_pldr_req(void)
522 { return 0; }
523
iwl_mei_alive_notif(bool success)524 static inline void iwl_mei_alive_notif(bool success)
525 {}
526
527 #endif /* CONFIG_IWLMEI */
528
529 #endif /* __iwl_mei_h__ */
530