htc.h

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/*
 * Copyright (c) 2004-2011 Atheros Communications Inc.
 * Copyright (c) 2011 Qualcomm Atheros, Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef HTC_H
#define HTC_H

#include "common.h"

/* frame header flags */

/* send direction */
#define HTC_FLAGS_NEED_CREDIT_UPDATE (1 << 0)
#define HTC_FLAGS_SEND_BUNDLE        (1 << 1)
#define HTC_FLAGS_TX_FIXUP_NETBUF    (1 << 2)

/* receive direction */
#define HTC_FLG_RX_UNUSED        (1 << 0)
#define HTC_FLG_RX_TRAILER       (1 << 1)
/* Bundle count maske and shift */
#define HTC_FLG_RX_BNDL_CNT  (0xF0)
#define HTC_FLG_RX_BNDL_CNT_S    4

#define HTC_HDR_LENGTH  (sizeof(struct htc_frame_hdr))
#define HTC_MAX_PAYLOAD_LENGTH   (4096 - sizeof(struct htc_frame_hdr))

/* HTC control message IDs */

#define HTC_MSG_READY_ID        1
#define HTC_MSG_CONN_SVC_ID     2
#define HTC_MSG_CONN_SVC_RESP_ID    3
#define HTC_MSG_SETUP_COMPLETE_ID   4
#define HTC_MSG_SETUP_COMPLETE_EX_ID    5

#define HTC_MAX_CTRL_MSG_LEN  256

#define HTC_VERSION_2P0  0x00
#define HTC_VERSION_2P1  0x01

#define HTC_SERVICE_META_DATA_MAX_LENGTH 128

#define HTC_CONN_FLGS_THRESH_LVL_QUAT       0x0
#define HTC_CONN_FLGS_THRESH_LVL_HALF       0x1
#define HTC_CONN_FLGS_THRESH_LVL_THREE_QUAT 0x2
#define HTC_CONN_FLGS_REDUCE_CRED_DRIB      0x4
#define HTC_CONN_FLGS_THRESH_MASK       0x3
/* disable credit flow control on a specific service */
#define HTC_CONN_FLGS_DISABLE_CRED_FLOW_CTRL          (1 << 3)
#define HTC_CONN_FLGS_SET_RECV_ALLOC_SHIFT    8
#define HTC_CONN_FLGS_SET_RECV_ALLOC_MASK     0xFF00

/* connect response status codes */
#define HTC_SERVICE_SUCCESS      0
#define HTC_SERVICE_NOT_FOUND    1
#define HTC_SERVICE_FAILED       2

/* no resources (i.e. no more endpoints) */
#define HTC_SERVICE_NO_RESOURCES 3

/* specific service is not allowing any more endpoints */
#define HTC_SERVICE_NO_MORE_EP   4

/* report record IDs */
#define HTC_RECORD_NULL             0
#define HTC_RECORD_CREDITS          1
#define HTC_RECORD_LOOKAHEAD        2
#define HTC_RECORD_LOOKAHEAD_BUNDLE 3

#define HTC_SETUP_COMP_FLG_RX_BNDL_EN     (1 << 0)
#define HTC_SETUP_COMP_FLG_DISABLE_TX_CREDIT_FLOW (1 << 1)

#define MAKE_SERVICE_ID(group, index) \
    (int)(((int)group << 8) | (int)(index))

/* NOTE: service ID of 0x0000 is reserved and should never be used */
#define HTC_CTRL_RSVD_SVC MAKE_SERVICE_ID(RSVD_SERVICE_GROUP, 1)
#define WMI_CONTROL_SVC   MAKE_SERVICE_ID(WMI_SERVICE_GROUP, 0)
#define WMI_DATA_BE_SVC   MAKE_SERVICE_ID(WMI_SERVICE_GROUP, 1)
#define WMI_DATA_BK_SVC   MAKE_SERVICE_ID(WMI_SERVICE_GROUP, 2)
#define WMI_DATA_VI_SVC   MAKE_SERVICE_ID(WMI_SERVICE_GROUP, 3)
#define WMI_DATA_VO_SVC   MAKE_SERVICE_ID(WMI_SERVICE_GROUP, 4)
#define WMI_MAX_SERVICES  5

#define WMM_NUM_AC  4

/* reserved and used to flush ALL packets */
#define HTC_TX_PACKET_TAG_ALL          0
#define HTC_SERVICE_TX_PACKET_TAG      1
#define HTC_TX_PACKET_TAG_USER_DEFINED (HTC_SERVICE_TX_PACKET_TAG + 9)

/* more packets on this endpoint are being fetched */
#define HTC_RX_FLAGS_INDICATE_MORE_PKTS  (1 << 0)

/* TODO.. for BMI */
#define ENDPOINT1 0
/* TODO -remove me, but we have to fix BMI first */
#define HTC_MAILBOX_NUM_MAX    4

/* enable send bundle padding for this endpoint */
#define HTC_FLGS_TX_BNDL_PAD_EN  (1 << 0)
#define HTC_EP_ACTIVE                            ((u32) (1u << 31))

/* HTC operational parameters */
#define HTC_TARGET_RESPONSE_TIMEOUT        2000 /* in ms */
#define HTC_TARGET_RESPONSE_POLL_WAIT      10
#define HTC_TARGET_RESPONSE_POLL_COUNT     200
#define HTC_TARGET_DEBUG_INTR_MASK         0x01
#define HTC_TARGET_CREDIT_INTR_MASK        0xF0

#define HTC_HOST_MAX_MSG_PER_BUNDLE        8
#define HTC_MIN_HTC_MSGS_TO_BUNDLE         2

/* packet flags */

#define HTC_RX_PKT_IGNORE_LOOKAHEAD      (1 << 0)
#define HTC_RX_PKT_REFRESH_HDR           (1 << 1)
#define HTC_RX_PKT_PART_OF_BUNDLE        (1 << 2)
#define HTC_RX_PKT_NO_RECYCLE            (1 << 3)

#define NUM_CONTROL_BUFFERS     8
#define NUM_CONTROL_TX_BUFFERS  2
#define NUM_CONTROL_RX_BUFFERS  (NUM_CONTROL_BUFFERS - NUM_CONTROL_TX_BUFFERS)

#define HTC_RECV_WAIT_BUFFERS        (1 << 0)
#define HTC_OP_STATE_STOPPING        (1 << 0)
#define HTC_OP_STATE_SETUP_COMPLETE  (1 << 1)

/*
 * The frame header length and message formats defined herein were selected
 * to accommodate optimal alignment for target processing. This reduces
 * code size and improves performance. Any changes to the header length may
 * alter the alignment and cause exceptions on the target. When adding to
 * the messagestructures insure that fields are properly aligned.
 */

/* HTC frame header
 *
 * NOTE: do not remove or re-arrange the fields, these are minimally
 * required to take advantage of 4-byte lookaheads in some hardware
 * implementations.
 */
struct htc_frame_hdr {
    u8 eid;
    u8 flags;

    /* length of data (including trailer) that follows the header */
    __le16 payld_len;

    /* end of 4-byte lookahead */

    u8 ctrl[2];
} __packed;

/* HTC ready message */
struct htc_ready_msg {
    __le16 msg_id;
    __le16 cred_cnt;
    __le16 cred_sz;
    u8 max_ep;
    u8 pad;
} __packed;

/* extended HTC ready message */
struct htc_ready_ext_msg {
    struct htc_ready_msg ver2_0_info;
    u8 htc_ver;
    u8 msg_per_htc_bndl;
} __packed;

/* connect service */
struct htc_conn_service_msg {
    __le16 msg_id;
    __le16 svc_id;
    __le16 conn_flags;
    u8 svc_meta_len;
    u8 pad;
} __packed;

/* connect response */
struct htc_conn_service_resp {
    __le16 msg_id;
    __le16 svc_id;
    u8 status;
    u8 eid;
    __le16 max_msg_sz;
    u8 svc_meta_len;
    u8 pad;
} __packed;

struct htc_setup_comp_msg {
    __le16 msg_id;
} __packed;

/* extended setup completion message */
struct htc_setup_comp_ext_msg {
    __le16 msg_id;
    __le32 flags;
    u8 msg_per_rxbndl;
    u8 Rsvd[3];
} __packed;

struct htc_record_hdr {
    u8 rec_id;
    u8 len;
} __packed;

struct htc_credit_report {
    u8 eid;
    u8 credits;
} __packed;

/*
 * NOTE: The lk_ahd array is guarded by a pre_valid
 * and Post Valid guard bytes. The pre_valid bytes must
 * equal the inverse of the post_valid byte.
 */
struct htc_lookahead_report {
    u8 pre_valid;
    u8 lk_ahd[4];
    u8 post_valid;
} __packed;

struct htc_bundle_lkahd_rpt {
    u8 lk_ahd[4];
} __packed;

/* Current service IDs */

enum htc_service_grp_ids {
    RSVD_SERVICE_GROUP = 0,
    WMI_SERVICE_GROUP = 1,

    HTC_TEST_GROUP = 254,
    HTC_SERVICE_GROUP_LAST = 255
};

/* ------ endpoint IDS ------ */

enum htc_endpoint_id {
    ENDPOINT_UNUSED = -1,
    ENDPOINT_0 = 0,
    ENDPOINT_1 = 1,
    ENDPOINT_2 = 2,
    ENDPOINT_3,
    ENDPOINT_4,
    ENDPOINT_5,
    ENDPOINT_6,
    ENDPOINT_7,
    ENDPOINT_8,
    ENDPOINT_MAX,
};

struct htc_tx_packet_info {
    u16 tag;
    int cred_used;
    u8 flags;
    int seqno;
};

struct htc_rx_packet_info {
    u32 exp_hdr;
    u32 rx_flags;
    u32 indicat_flags;
};

struct htc_target;

/* wrapper around endpoint-specific packets */
struct htc_packet {
    struct list_head list;

    /* caller's per packet specific context */
    void *pkt_cntxt;

    /*
     * the true buffer start , the caller can store the real
     * buffer start here.  In receive callbacks, the HTC layer
     * sets buf to the start of the payload past the header.
     * This field allows the caller to reset buf when it recycles
     * receive packets back to HTC.
     */
    u8 *buf_start;

    /*
     * Pointer to the start of the buffer. In the transmit
     * direction this points to the start of the payload. In the
     * receive direction, however, the buffer when queued up
     * points to the start of the HTC header but when returned
     * to the caller points to the start of the payload
     */
    u8 *buf;
    u32 buf_len;

    /* actual length of payload */
    u32 act_len;

    /* endpoint that this packet was sent/recv'd from */
    enum htc_endpoint_id endpoint;

    /* completion status */

    int status;
    union {
        struct htc_tx_packet_info tx;
        struct htc_rx_packet_info rx;
    } info;

    void (*completion) (struct htc_target *, struct htc_packet *);
    struct htc_target *context;

    /*
     * optimization for network-oriented data, the HTC packet
     * can pass the network buffer corresponding to the HTC packet
     * lower layers may optimized the transfer knowing this is
     * a network buffer
     */
    struct sk_buff *skb;
};

enum htc_send_full_action {
    HTC_SEND_FULL_KEEP = 0,
    HTC_SEND_FULL_DROP = 1,
};

struct htc_ep_callbacks {
    void (*tx_complete) (struct htc_target *, struct htc_packet *);
    void (*rx) (struct htc_target *, struct htc_packet *);
    void (*rx_refill) (struct htc_target *, enum htc_endpoint_id endpoint);
    enum htc_send_full_action (*tx_full) (struct htc_target *,
                          struct htc_packet *);
    struct htc_packet *(*rx_allocthresh) (struct htc_target *,
                          enum htc_endpoint_id, int);
    void (*tx_comp_multi) (struct htc_target *, struct list_head *);
    int rx_alloc_thresh;
    int rx_refill_thresh;
};

/* service connection information */
struct htc_service_connect_req {
    u16 svc_id;
    u16 conn_flags;
    struct htc_ep_callbacks ep_cb;
    int max_txq_depth;
    u32 flags;
    unsigned int max_rxmsg_sz;
};

/* service connection response information */
struct htc_service_connect_resp {
    u8 buf_len;
    u8 act_len;
    enum htc_endpoint_id endpoint;
    unsigned int len_max;
    u8 resp_code;
};

/* endpoint distributionstructure */
struct htc_endpoint_credit_dist {
    struct list_head list;

    /* Service ID (set by HTC) */
    u16 svc_id;

    /* endpoint for this distributionstruct (set by HTC) */
    enum htc_endpoint_id endpoint;

    u32 dist_flags;

    /*
     * credits for normal operation, anything above this
     * indicates the endpoint is over-subscribed.
     */
    int cred_norm;

    /* floor for credit distribution */
    int cred_min;

    int cred_assngd;

    /* current credits available */
    int credits;

    /*
     * pending credits to distribute on this endpoint, this
     * is set by HTC when credit reports arrive.  The credit
     * distribution functions sets this to zero when it distributes
     * the credits.
     */
    int cred_to_dist;

    /*
     * the number of credits that the current pending TX packet needs
     * to transmit. This is set by HTC when endpoint needs credits in
     * order to transmit.
     */
    int seek_cred;

    /* size in bytes of each credit */
    int cred_sz;

    /* credits required for a maximum sized messages */
    int cred_per_msg;

    /* reserved for HTC use */
    struct htc_endpoint *htc_ep;

    /*
     * current depth of TX queue , i.e. messages waiting for credits
     * This field is valid only when HTC_CREDIT_DIST_ACTIVITY_CHANGE
     * or HTC_CREDIT_DIST_SEND_COMPLETE is indicated on an endpoint
     * that has non-zero credits to recover.
     */
    int txq_depth;
};

/*
 * credit distibution code that is passed into the distrbution function,
 * there are mandatory and optional codes that must be handled
 */
enum htc_credit_dist_reason {
    HTC_CREDIT_DIST_SEND_COMPLETE = 0,
    HTC_CREDIT_DIST_ACTIVITY_CHANGE = 1,
    HTC_CREDIT_DIST_SEEK_CREDITS,
};

struct ath6kl_htc_credit_info {
    int total_avail_credits;
    int cur_free_credits;

    /* list of lowest priority endpoints */
    struct list_head lowestpri_ep_dist;
};

/* endpoint statistics */
struct htc_endpoint_stats {
    /*
     * number of times the host set the credit-low flag in a send
     * message on this endpoint
     */
    u32 cred_low_indicate;

    u32 tx_issued;
    u32 tx_pkt_bundled;
    u32 tx_bundles;
    u32 tx_dropped;

    /* running count of total credit reports received for this endpoint */
    u32 tx_cred_rpt;

    /* credit reports received from this endpoint's RX packets */
    u32 cred_rpt_from_rx;

    /* credit reports received from RX packets of other endpoints */
    u32 cred_rpt_from_other;

    /* credit reports received from endpoint 0 RX packets */
    u32 cred_rpt_ep0;

    /* count of credits received via Rx packets on this endpoint */
    u32 cred_from_rx;

    /* count of credits received via another endpoint */
    u32 cred_from_other;

    /* count of credits received via another endpoint */
    u32 cred_from_ep0;

    /* count of consummed credits */
    u32 cred_cosumd;

    /* count of credits returned */
    u32 cred_retnd;

    u32 rx_pkts;

    /* count of lookahead records found in Rx msg */
    u32 rx_lkahds;

    /* count of recv packets received in a bundle */
    u32 rx_bundl;

    /* count of number of bundled lookaheads */
    u32 rx_bundle_lkahd;

    /* count of the number of bundle indications from the HTC header */
    u32 rx_bundle_from_hdr;

    /* the number of times the recv allocation threshold was hit */
    u32 rx_alloc_thresh_hit;

    /* total number of bytes */
    u32 rxalloc_thresh_byte;
};

struct htc_endpoint {
    enum htc_endpoint_id eid;
    u16 svc_id;
    struct list_head txq;
    struct list_head rx_bufq;
    struct htc_endpoint_credit_dist cred_dist;
    struct htc_ep_callbacks ep_cb;
    int max_txq_depth;
    int len_max;
    int tx_proc_cnt;
    int rx_proc_cnt;
    struct htc_target *target;
    u8 seqno;
    u32 conn_flags;
    struct htc_endpoint_stats ep_st;
    u16 tx_drop_packet_threshold;

    struct {
        u8 pipeid_ul;
        u8 pipeid_dl;
        struct list_head tx_lookup_queue;
        bool tx_credit_flow_enabled;
    } pipe;
};

struct htc_control_buffer {
    struct htc_packet packet;
    u8 *buf;
};

struct htc_pipe_txcredit_alloc {
    u16 service_id;
    u8 credit_alloc;
};

enum htc_send_queue_result {
    HTC_SEND_QUEUE_OK = 0,  /* packet was queued */
    HTC_SEND_QUEUE_DROP = 1,    /* this packet should be dropped */
};

struct ath6kl_htc_ops {
    void* (*create)(struct ath6kl *ar);
    int (*wait_target)(struct htc_target *target);
    int (*start)(struct htc_target *target);
    int (*conn_service)(struct htc_target *target,
                struct htc_service_connect_req *req,
                struct htc_service_connect_resp *resp);
    int  (*tx)(struct htc_target *target, struct htc_packet *packet);
    void (*stop)(struct htc_target *target);
    void (*cleanup)(struct htc_target *target);
    void (*flush_txep)(struct htc_target *target,
               enum htc_endpoint_id endpoint, u16 tag);
    void (*flush_rx_buf)(struct htc_target *target);
    void (*activity_changed)(struct htc_target *target,
                 enum htc_endpoint_id endpoint,
                 bool active);
    int (*get_rxbuf_num)(struct htc_target *target,
                 enum htc_endpoint_id endpoint);
    int (*add_rxbuf_multiple)(struct htc_target *target,
                  struct list_head *pktq);
    int (*credit_setup)(struct htc_target *target,
                struct ath6kl_htc_credit_info *cred_info);
    int (*tx_complete)(struct ath6kl *ar, struct sk_buff *skb);
    int (*rx_complete)(struct ath6kl *ar, struct sk_buff *skb, u8 pipe);
};

struct ath6kl_device;

/* our HTC target state */
struct htc_target {
    struct htc_endpoint endpoint[ENDPOINT_MAX];

    /* contains struct htc_endpoint_credit_dist */
    struct list_head cred_dist_list;

    struct list_head free_ctrl_txbuf;
    struct list_head free_ctrl_rxbuf;
    struct ath6kl_htc_credit_info *credit_info;
    int tgt_creds;
    unsigned int tgt_cred_sz;

    /* protects free_ctrl_txbuf and free_ctrl_rxbuf */
    spinlock_t htc_lock;

    /* FIXME: does this protext rx_bufq and endpoint structures or what? */
    spinlock_t rx_lock;

    /* protects endpoint->txq */
    spinlock_t tx_lock;

    struct ath6kl_device *dev;
    u32 htc_flags;
    u32 rx_st_flags;
    enum htc_endpoint_id ep_waiting;
    u8 htc_tgt_ver;

    /* max messages per bundle for HTC */
    int msg_per_bndl_max;

    u32 tx_bndl_mask;
    int rx_bndl_enable;
    int max_rx_bndl_sz;
    int max_tx_bndl_sz;

    u32 block_sz;
    u32 block_mask;

    int max_scat_entries;
    int max_xfer_szper_scatreq;

    int chk_irq_status_cnt;

    /* counts the number of Tx without bundling continously per AC */
    u32 ac_tx_count[WMM_NUM_AC];

    struct {
        struct htc_packet *htc_packet_pool;
        u8 ctrl_response_buf[HTC_MAX_CTRL_MSG_LEN];
        int ctrl_response_len;
        bool ctrl_response_valid;
        struct htc_pipe_txcredit_alloc txcredit_alloc[ENDPOINT_MAX];
    } pipe;
};

int ath6kl_htc_rxmsg_pending_handler(struct htc_target *target,
                     u32 msg_look_ahead, int *n_pkts);

static inline void set_htc_pkt_info(struct htc_packet *packet, void *context,
                    u8 *buf, unsigned int len,
                    enum htc_endpoint_id eid, u16 tag)
{
    packet->pkt_cntxt = context;
    packet->buf = buf;
    packet->act_len = len;
    packet->endpoint = eid;
    packet->info.tx.tag = tag;
}

static inline void htc_rxpkt_reset(struct htc_packet *packet)
{
    packet->buf = packet->buf_start;
    packet->act_len = 0;
}

static inline void set_htc_rxpkt_info(struct htc_packet *packet, void *context,
                      u8 *buf, unsigned long len,
                      enum htc_endpoint_id eid)
{
    packet->pkt_cntxt = context;
    packet->buf = buf;
    packet->buf_start = buf;
    packet->buf_len = len;
    packet->endpoint = eid;
}

static inline int get_queue_depth(struct list_head *queue)
{
    struct list_head *tmp_list;
    int depth = 0;

    list_for_each(tmp_list, queue)
        depth++;

    return depth;
}

void ath6kl_htc_pipe_attach(struct ath6kl *ar);
void ath6kl_htc_mbox_attach(struct ath6kl *ar);

#endif