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| -rw-r--r-- | drivers/net/wireless/intel/iwlwifi/mei/iwl-mei.h | 505 |
1 files changed, 505 insertions, 0 deletions
diff --git a/drivers/net/wireless/intel/iwlwifi/mei/iwl-mei.h b/drivers/net/wireless/intel/iwlwifi/mei/iwl-mei.h new file mode 100644 index 000000000000..67122cfa2292 --- /dev/null +++ b/drivers/net/wireless/intel/iwlwifi/mei/iwl-mei.h @@ -0,0 +1,505 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Intel Corporation + */ + +#ifndef __iwl_mei_h__ +#define __iwl_mei_h__ + +#include <linux/if_ether.h> +#include <linux/skbuff.h> +#include <linux/ieee80211.h> + +/** + * DOC: Introduction + * + * iwlmei is the kernel module that is in charge of the commnunication between + * the iwlwifi driver and the CSME firmware's WLAN driver. This communication + * uses the SAP protocol defined in another file. + * iwlwifi can request or release ownership on the WiFi device through iwlmei. + * iwlmei may notify iwlwifi about certain events: what filter iwlwifi should + * use to passthrough inbound packets to the CSME firmware for example. iwlmei + * may also use iwlwifi to send traffic. This means that we need communication + * from iwlmei to iwlwifi and the other way around. + */ + +/** + * DOC: Life cycle + * + * iwlmei exports symbols that are needed by iwlwifi so that iwlmei will always + * be loaded when iwlwifi is alive. iwlwifi registers itself to iwlmei and + * provides the pointers to the functions that iwlmei calls whenever needed. + * iwlwifi calls iwlmei through direct and context-free function calls. + * It is assumed that only one device is accessible to the CSME firmware and + * under the scope of iwlmei so that it is valid not to have any context passed + * to iwlmei's functions. + * + * There are cases in which iwlmei can't access the CSME firmware, because the + * CSME firmware is undergoing a reset, or the mei bus decided to unbind the + * device. In those cases, iwlmei will need not to send requests over the mei + * bus. Instead, it needs to cache the requests from iwlwifi and fulfill them + * when the mei bus is available again. + * + * iwlmei can call iwlwifi as long as iwlwifi is registered to iwlmei. When + * iwlwifi goes down (the PCI device is unbound, or the iwlwifi is unloaded) + * iwlwifi needs to unregister from iwlmei. + */ + +/** + * DOC: Memory layout + * + * Since iwlwifi calls iwlmei without any context, iwlmei needs to hold a + * global pointer to its data (which is in the mei client device's private + * data area). If there was no bind on the mei bus, this pointer is NULL and + * iwlmei knows not access to the CSME firmware upon requests from iwlwifi. + * + * iwlmei needs to cache requests from iwlwifi when there is no mei client + * device available (when iwlmei has been removed from the mei bus). In this + * case, all iwlmei's data that resides in the mei client device's private data + * area is unavailable. For this specific case, a separate caching area is + * needed. + */ + +/** + * DOC: Concurrency + * + * iwlwifi can call iwlmei at any time. iwlmei will take care to synchronize + * the calls from iwlwifi with its internal flows. iwlwifi must not call iwlmei + * in flows that cannot sleep. Moreover, iwlwifi must not call iwlmei in flows + * that originated from iwlmei. + */ + +/** + * DOC: Probe and remove from mei bus driver + * + * When the mei bus driver enumerates its devices, it calls the iwlmei's probe + * function which will send the %SAP_ME_MSG_START message. The probe completes + * before the response (%SAP_ME_MSG_START_OK) is received. This response will + * be handle by the Rx path. Once it arrives, the connection to the CSME + * firmware is considered established and iwlwifi's requests can be treated + * against the CSME firmware. + * + * When the mei bus driver removes the device, iwlmei loses all the data that + * was attached to the mei client device. It clears the global pointer to the + * mei client device since it is not available anymore. This will cause all the + * requests coming from iwlwifi to be cached. This flow takes the global mutex + * to be synchronized with all the requests coming from iwlwifi. + */ + +/** + * DOC: Driver load when CSME owns the device + * + * When the driver (iwlwifi) is loaded while CSME owns the device, + * it'll ask CSME to release the device through HW registers. CSME + * will release the device only in the case that there is no connection + * through the mei bus. If there is a mei bus connection, CSME will refuse + * to release the ownership on the device through the HW registers. In that + * case, iwlwifi must first request ownership using the SAP protocol. + * + * Once iwlwifi will request ownership through the SAP protocol, CSME will + * grant the ownership on the device through the HW registers as well. + * In order to request ownership over SAP, we first need to have an interface + * which means that we need to register to mac80211. + * This can't happen before we get the NVM that contains all the capabilities + * of the device. Reading the NVM usually requires the load the firmware, but + * this is impossible as long as we don't have ownership on the device. + * In order to solve this chicken and egg problem, the host driver can get + * the NVM through CSME which owns the device. It can send + * %SAP_MSG_NOTIF_GET_NVM, which will be replied by %SAP_MSG_NOTIF_NVM with + * the NVM's content that the host driver needs. + */ + +/** + * DOC: CSME behavior regarding the ownership requests + * + * The ownership requests from the host can come in two different ways: + * - the HW registers in iwl_pcie_set_hw_ready + * - using the Software Arbitration Protocol (SAP) + * + * The host can ask CSME who owns the device with %SAP_MSG_NOTIF_WHO_OWNS_NIC, + * and it can request ownership with %SAP_MSG_NOTIF_HOST_ASKS_FOR_NIC_OWNERSHIP. + * The host will first use %SAP_MSG_NOTIF_WHO_OWNS_NIC to know what state + * CSME is in. In case CSME thinks it owns the device, the host can ask for + * ownership with %SAP_MSG_NOTIF_HOST_ASKS_FOR_NIC_OWNERSHIP. + * + * Here the table that describes CSME's behavior upon ownership request: + * + * +-------------------+------------+--------------+-----------------------------+------------+ + * | State | HW reg bit | Reply for | Event | HW reg bit | + * | | before | WHO_OWNS_NIC | | after | + * +===================+============+==============+=============================+============+ + * | WiAMT not | 0 | Host | HW register or | 0 | + * | operational | Host owner | | HOST_ASKS_FOR_NIC_OWNERSHIP | Host owner | + * +-------------------+------------+--------------+-----------------------------+------------+ + * | Operational & | 1 | N/A | HW register | 0 | + * | SAP down & | CSME owner | | | Host owner | + * | no session active | | | | | + * +-------------------+------------+--------------+-----------------------------+------------+ + * | Operational & | 1 | CSME | HW register | 1 | + * | SAP up | CSME owner | | | CSME owner | + * +-------------------+------------+--------------+-----------------------------+------------+ + * | Operational & | 1 | CSME | HOST_ASKS_FOR_NIC_OWNERSHIP | 0 | + * | SAP up | CSME owner | | | Host owner | + * +-------------------+------------+--------------+-----------------------------+------------+ + */ + +/** + * DOC: Driver load when CSME is associated and a session is active + * + * A "session" is active when CSME is associated to an access point and the + * link is used to attach a remote driver or to control the system remotely. + * When a session is active, we want to make sure it won't disconnect when we + * take ownership on the device. + * In this case, the driver can get the device, but it'll need to make + * sure that it'll connect to the exact same AP (same BSSID). + * In order to do so, CSME will send the connection parameters through + * SAP and then the host can check if it can connect to this same AP. + * If yes, it can request ownership through SAP and connect quickly without + * scanning all the channels, but just probing the AP on the channel that + * CSME was connected to. + * In order to signal this specific scenario to iwlwifi, iwlmei will + * immediately require iwlwifi to report RF-Kill to the network stack. This + * RF-Kill will prevent the stack from getting the device, and it has a reason + * that tells the userspace that the device is in RF-Kill because it is not + * owned by the host. Once the userspace has configured the right profile, + * it'll be able to let iwlmei know that it can request ownership over SAP + * which will remove the RF-Kill, and finally allow the host to connect. + * The host has then 3 seconds to connect (including DHCP). Had the host + * failed to connect within those 3 seconds, CSME will take the device back. + */ + +/** + * DOC: Datapath + * + * CSME can transmit packets, through the netdev that it gets from the wifi + * driver. It'll send packet in the 802.3 format and simply call + * dev_queue_xmit. + * + * For Rx, iwlmei registers a Rx handler that it attaches to the netdev. iwlmei + * may catch packets and send them to CSME, it can then either drop them so + * that they are invisible to user space, or let them go the user space. + * + * Packets transmitted by the user space do not need to be forwarded to CSME + * with the exception of the DHCP request. In order to know what IP is used + * by the user space, CSME needs to get the DHCP request. See + * iwl_mei_tx_copy_to_csme(). + */ + +/** + * enum iwl_mei_nvm_caps - capabilities for MEI NVM + * @MEI_NVM_CAPS_LARI_SUPPORT: Lari is supported + * @MEI_NVM_CAPS_11AX_SUPPORT: 11AX is supported + */ +enum iwl_mei_nvm_caps { + MEI_NVM_CAPS_LARI_SUPPORT = BIT(0), + MEI_NVM_CAPS_11AX_SUPPORT = BIT(1), +}; + +/** + * struct iwl_mei_nvm - used to pass the NVM from CSME + * @hw_addr: The MAC address + * @n_hw_addrs: The number of MAC addresses + * @reserved: For alignment. + * @radio_cfg: The radio configuration. + * @caps: See &enum iwl_mei_nvm_caps. + * @nvm_version: The version of the NVM. + * @channels: The data for each channel. + * + * If a field is added, it must correspond to the SAP structure. + */ +struct iwl_mei_nvm { + u8 hw_addr[ETH_ALEN]; + u8 n_hw_addrs; + u8 reserved; + u32 radio_cfg; + u32 caps; + u32 nvm_version; + u32 channels[110]; +}; + +/** + * enum iwl_mei_pairwise_cipher - cipher for UCAST key + * @IWL_MEI_CIPHER_NONE: none + * @IWL_MEI_CIPHER_CCMP: ccmp + * @IWL_MEI_CIPHER_GCMP: gcmp + * @IWL_MEI_CIPHER_GCMP_256: gcmp 256 + * + * Note that those values are dictated by the CSME firmware API (see sap.h) + */ +enum iwl_mei_pairwise_cipher { + IWL_MEI_CIPHER_NONE = 0, + IWL_MEI_CIPHER_CCMP = 4, + IWL_MEI_CIPHER_GCMP = 8, + IWL_MEI_CIPHER_GCMP_256 = 9, +}; + +/** + * enum iwl_mei_akm_auth - a combination of AKM and AUTH method + * @IWL_MEI_AKM_AUTH_OPEN: No encryption + * @IWL_MEI_AKM_AUTH_RSNA: 1X profile + * @IWL_MEI_AKM_AUTH_RSNA_PSK: PSK profile + * @IWL_MEI_AKM_AUTH_SAE: SAE profile + * + * Note that those values are dictated by the CSME firmware API (see sap.h) + */ +enum iwl_mei_akm_auth { + IWL_MEI_AKM_AUTH_OPEN = 0, + IWL_MEI_AKM_AUTH_RSNA = 6, + IWL_MEI_AKM_AUTH_RSNA_PSK = 7, + IWL_MEI_AKM_AUTH_SAE = 9, +}; + +/** + * struct iwl_mei_conn_info - connection info + * @lp_state: link protection state + * @auth_mode: authentication mode + * @ssid_len: the length of SSID + * @ssid: the SSID + * @pairwise_cipher: the cipher used for unicast packets + * @channel: the associated channel + * @band: the associated band + * @bssid: the BSSID + */ +struct iwl_mei_conn_info { + u8 lp_state; + u8 auth_mode; + u8 ssid_len; + u8 channel; + u8 band; + u8 pairwise_cipher; + u8 bssid[ETH_ALEN]; + u8 ssid[IEEE80211_MAX_SSID_LEN]; +}; + +/** + * struct iwl_mei_colloc_info - collocated AP info + * @channel: the channel of the collocated AP + * @bssid: the BSSID of the collocated AP + */ +struct iwl_mei_colloc_info { + u8 channel; + u8 bssid[ETH_ALEN]; +}; + +/* + * struct iwl_mei_ops - driver's operations called by iwlmei + * Operations will not be called more than once concurrently. + * It's not allowed to call iwlmei functions from this context. + * + * @me_conn_status: provide information about CSME's current connection. + * @rfkill: called when the wifi driver should report a change in the rfkill + * status. + * @roaming_forbidden: indicates whether roaming is forbidden. + * @sap_connected: indicate that SAP is now connected. Will be called in case + * the wifi driver registered to iwlmei before SAP connection succeeded or + * when the SAP connection is re-established. + * @nic_stolen: this means that device is no longer available. The device can + * still be used until the callback returns. + */ +struct iwl_mei_ops { + void (*me_conn_status)(void *priv, + const struct iwl_mei_conn_info *conn_info); + void (*rfkill)(void *priv, bool blocked); + void (*roaming_forbidden)(void *priv, bool forbidden); + void (*sap_connected)(void *priv); + void (*nic_stolen)(void *priv); +}; + +#if IS_ENABLED(CONFIG_IWLMEI) + +/** + * iwl_mei_is_connected() - is the connection to the CSME firmware established? + * + * Return: true if we have a SAP connection + */ +bool iwl_mei_is_connected(void); + +/** + * iwl_mei_get_nvm() - returns the NVM for the device + * + * It is the caller's responsibility to free the memory returned + * by this function. + * This function blocks (sleeps) until the NVM is ready. + * + * Return: the NVM as received from CSME + */ +struct iwl_mei_nvm *iwl_mei_get_nvm(void); + +/** + * iwl_mei_get_ownership() - request ownership + * + * This function blocks until ownership is granted or timeout expired. + * + * Return: 0 in case we could get ownership on the device + */ +int iwl_mei_get_ownership(void); + +/** + * iwl_mei_set_rfkill_state() - set SW and HW RF kill states + * @hw_rfkill: HW RF kill state. + * @sw_rfkill: SW RF kill state. + * + * This function must be called when SW RF kill is issued by the user. + */ +void iwl_mei_set_rfkill_state(bool hw_rfkill, bool sw_rfkill); + +/** + * iwl_mei_set_nic_info() - set mac address + * @mac_address: mac address to set + * @nvm_address: NVM mac adsress to set + * + * This function must be called upon mac address change. + */ +void iwl_mei_set_nic_info(const u8 *mac_address, const u8 *nvm_address); + +/** + * iwl_mei_set_country_code() - set new country code + * @mcc: the new applied MCC + * + * This function must be called upon country code update + */ +void iwl_mei_set_country_code(u16 mcc); + +/** + * iwl_mei_set_power_limit() - set TX power limit + * @power_limit: pointer to an array of 10 elements (le16) represents the power + * restrictions per chain. + * + * This function must be called upon power restrictions change + */ +void iwl_mei_set_power_limit(const __le16 *power_limit); + +/** + * iwl_mei_register() - register the wifi driver to iwlmei + * @priv: a pointer to the wifi driver's context. Cannot be NULL. + * @ops: the ops structure. + * + * Return: 0 unless something went wrong. It is illegal to call any + * other API function before this function is called and succeeds. + * + * Only one wifi driver instance (wifi device instance really) + * can register at a time. + */ +int iwl_mei_register(void *priv, const struct iwl_mei_ops *ops); + +/** + * iwl_mei_start_unregister() - unregister the wifi driver from iwlmei + * + * From this point on, iwlmei will not used the callbacks provided by + * the driver, but the device is still usable. + */ +void iwl_mei_start_unregister(void); + +/** + * iwl_mei_unregister_complete() - complete the unregistration + * + * Must be called after iwl_mei_start_unregister. When this function returns, + * the device is owned by CSME. + */ +void iwl_mei_unregister_complete(void); + +/** + * iwl_mei_set_netdev() - sets the netdev for Tx / Rx. + * @netdev: the net_device + * + * The caller should set the netdev to a non-NULL value when the + * interface is added. Packets might be sent to the driver immediately + * afterwards. + * The caller should set the netdev to NULL when the interface is removed. + * This function will call synchronize_net() after setting the netdev to NULL. + * Only when this function returns, can the caller assume that iwlmei will + * no longer inject packets into the netdev's Tx path. + * + * Context: This function can sleep and assumes rtnl_lock is taken. + * The netdev must be set to NULL before iwl_mei_start_unregister() is called. + */ +void iwl_mei_set_netdev(struct net_device *netdev); + +/** + * iwl_mei_tx_copy_to_csme() - must be called for each packet sent by + * the wifi driver. + * @skb: the skb sent + * @ivlen: the size of the IV that needs to be skipped after the MAC and + * before the SNAP header. + * + * This function doesn't take any lock, it simply tries to catch DHCP + * packets sent by the wifi driver. If the packet is a DHCP packet, it + * will send it to CSME. This function must not be called for virtual + * interfaces that are not monitored by CSME, meaning it must be called + * only for packets transmitted by the netdevice that was registered + * with iwl_mei_set_netdev(). + */ +void iwl_mei_tx_copy_to_csme(struct sk_buff *skb, unsigned int ivlen); + +/** + * iwl_mei_host_associated() - must be called when iwlwifi associated. + * @conn_info: pointer to the connection info structure. + * @colloc_info: pointer to the collocated AP info. This is relevant only in + * case of UHB associated AP, otherwise set to NULL. + */ +void iwl_mei_host_associated(const struct iwl_mei_conn_info *conn_info, + const struct iwl_mei_colloc_info *colloc_info); + +/** + * iwl_mei_host_disassociated() - must be called when iwlwifi disassociated. + */ +void iwl_mei_host_disassociated(void); + +/** + * iwl_mei_device_down() - must be called when the device is down + */ +void iwl_mei_device_down(void); + +#else + +static inline bool iwl_mei_is_connected(void) +{ return false; } + +static inline struct iwl_mei_nvm *iwl_mei_get_nvm(void) +{ return NULL; } + +static inline int iwl_mei_get_ownership(void) +{ return 0; } + +static inline void iwl_mei_set_rfkill_state(bool hw_rfkill, bool sw_rfkill) +{} + +static inline void iwl_mei_set_nic_info(const u8 *mac_address, const u8 *nvm_address) +{} + +static inline void iwl_mei_set_country_code(u16 mcc) +{} + +static inline void iwl_mei_set_power_limit(__le16 *power_limit) +{} + +static inline int iwl_mei_register(void *priv, + const struct iwl_mei_ops *ops) +{ return 0; } + +static inline void iwl_mei_start_unregister(void) +{} + +static inline void iwl_mei_unregister_complete(void) +{} + +static inline void iwl_mei_set_netdev(struct net_device *netdev) +{} + +static inline void iwl_mei_tx_copy_to_csme(struct sk_buff *skb, + unsigned int ivlen) +{} + +static inline void iwl_mei_host_associated(const struct iwl_mei_conn_info *conn_info, + const struct iwl_mei_colloc_info *colloc_info) +{} + +static inline void iwl_mei_host_disassociated(void) +{} + +static inline void iwl_mei_device_down(void) +{} + +#endif /* CONFIG_IWLMEI */ + +#endif /* __iwl_mei_h__ */ |