rx.c

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/*
 * This file is part of wl1271
 *
 * Copyright (C) 2009 Nokia Corporation
 *
 * Contact: Luciano Coelho <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/gfp.h>
#include <linux/sched.h>

#include "wlcore.h"
#include "debug.h"
#include "acx.h"
#include "rx.h"
#include "tx.h"
#include "io.h"
#include "hw_ops.h"

/*
 * TODO: this is here just for now, it must be removed when the data
 * operations are in place.
 */
#include "../wl12xx/reg.h"

static u32 wlcore_rx_get_buf_size(struct wl1271 *wl,
                  u32 rx_pkt_desc)
{
    if (wl->quirks & WLCORE_QUIRK_RX_BLOCKSIZE_ALIGN)
        return (rx_pkt_desc & ALIGNED_RX_BUF_SIZE_MASK) >>
               ALIGNED_RX_BUF_SIZE_SHIFT;

    return (rx_pkt_desc & RX_BUF_SIZE_MASK) >> RX_BUF_SIZE_SHIFT_DIV;
}

static u32 wlcore_rx_get_align_buf_size(struct wl1271 *wl, u32 pkt_len)
{
    if (wl->quirks & WLCORE_QUIRK_RX_BLOCKSIZE_ALIGN)
        return ALIGN(pkt_len, WL12XX_BUS_BLOCK_SIZE);

    return pkt_len;
}

static void wl1271_rx_status(struct wl1271 *wl,
                 struct wl1271_rx_descriptor *desc,
                 struct ieee80211_rx_status *status,
                 u8 beacon)
{
    memset(status, 0, sizeof(struct ieee80211_rx_status));

    if ((desc->flags & WL1271_RX_DESC_BAND_MASK) == WL1271_RX_DESC_BAND_BG)
        status->band = IEEE80211_BAND_2GHZ;
    else
        status->band = IEEE80211_BAND_5GHZ;

    status->rate_idx = wlcore_rate_to_idx(wl, desc->rate, status->band);

    /* 11n support */
    if (desc->rate <= wl->hw_min_ht_rate)
        status->flag |= RX_FLAG_HT;

    status->signal = desc->rssi;

    /*
     * FIXME: In wl1251, the SNR should be divided by two.  In wl1271 we
     * need to divide by two for now, but TI has been discussing about
     * changing it.  This needs to be rechecked.
     */
    wl->noise = desc->rssi - (desc->snr >> 1);

    status->freq = ieee80211_channel_to_frequency(desc->channel,
                              status->band);

    if (desc->flags & WL1271_RX_DESC_ENCRYPT_MASK) {
        u8 desc_err_code = desc->status & WL1271_RX_DESC_STATUS_MASK;

        status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED |
                RX_FLAG_DECRYPTED;

        if (unlikely(desc_err_code == WL1271_RX_DESC_MIC_FAIL)) {
            status->flag |= RX_FLAG_MMIC_ERROR;
            wl1271_warning("Michael MIC error");
        }
    }
}

static int wl1271_rx_handle_data(struct wl1271 *wl, u8 *data, u32 length,
                 enum wl_rx_buf_align rx_align, u8 *hlid)
{
    struct wl1271_rx_descriptor *desc;
    struct sk_buff *skb;
    struct ieee80211_hdr *hdr;
    u8 *buf;
    u8 beacon = 0;
    u8 is_data = 0;
    u8 reserved = 0;
    u16 seq_num;
    u32 pkt_data_len;

    /*
     * In PLT mode we seem to get frames and mac80211 warns about them,
     * workaround this by not retrieving them at all.
     */
    if (unlikely(wl->plt))
        return -EINVAL;

    pkt_data_len = wlcore_hw_get_rx_packet_len(wl, data, length);
    if (!pkt_data_len) {
        wl1271_error("Invalid packet arrived from HW. length %d",
                 length);
        return -EINVAL;
    }

    if (rx_align == WLCORE_RX_BUF_UNALIGNED)
        reserved = RX_BUF_ALIGN;

    /* the data read starts with the descriptor */
    desc = (struct wl1271_rx_descriptor *) data;

    if (desc->packet_class == WL12XX_RX_CLASS_LOGGER) {
        size_t len = length - sizeof(*desc);
        wl12xx_copy_fwlog(wl, data + sizeof(*desc), len);
        wake_up_interruptible(&wl->fwlog_waitq);
        return 0;
    }

    switch (desc->status & WL1271_RX_DESC_STATUS_MASK) {
    /* discard corrupted packets */
    case WL1271_RX_DESC_DRIVER_RX_Q_FAIL:
    case WL1271_RX_DESC_DECRYPT_FAIL:
        wl1271_warning("corrupted packet in RX with status: 0x%x",
                   desc->status & WL1271_RX_DESC_STATUS_MASK);
        return -EINVAL;
    case WL1271_RX_DESC_SUCCESS:
    case WL1271_RX_DESC_MIC_FAIL:
        break;
    default:
        wl1271_error("invalid RX descriptor status: 0x%x",
                 desc->status & WL1271_RX_DESC_STATUS_MASK);
        return -EINVAL;
    }

    /* skb length not including rx descriptor */
    skb = __dev_alloc_skb(pkt_data_len + reserved, GFP_KERNEL);
    if (!skb) {
        wl1271_error("Couldn't allocate RX frame");
        return -ENOMEM;
    }

    /* reserve the unaligned payload(if any) */
    skb_reserve(skb, reserved);

    buf = skb_put(skb, pkt_data_len);

    /*
     * Copy packets from aggregation buffer to the skbs without rx
     * descriptor and with packet payload aligned care. In case of unaligned
     * packets copy the packets in offset of 2 bytes guarantee IP header
     * payload aligned to 4 bytes.
     */
    memcpy(buf, data + sizeof(*desc), pkt_data_len);
    if (rx_align == WLCORE_RX_BUF_PADDED)
        skb_pull(skb, RX_BUF_ALIGN);

    *hlid = desc->hlid;

    hdr = (struct ieee80211_hdr *)skb->data;
    if (ieee80211_is_beacon(hdr->frame_control))
        beacon = 1;
    if (ieee80211_is_data_present(hdr->frame_control))
        is_data = 1;

    wl1271_rx_status(wl, desc, IEEE80211_SKB_RXCB(skb), beacon);
    wlcore_hw_set_rx_csum(wl, desc, skb);

    seq_num = (le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_SEQ) >> 4;
    wl1271_debug(DEBUG_RX, "rx skb 0x%p: %d B %s seq %d hlid %d", skb,
             skb->len - desc->pad_len,
             beacon ? "beacon" : "",
             seq_num, *hlid);

    skb_queue_tail(&wl->deferred_rx_queue, skb);
    queue_work(wl->freezable_wq, &wl->netstack_work);

    return is_data;
}

int wlcore_rx(struct wl1271 *wl, struct wl_fw_status_1 *status)
{
    unsigned long active_hlids[BITS_TO_LONGS(WL12XX_MAX_LINKS)] = {0};
    u32 buf_size;
    u32 fw_rx_counter = status->fw_rx_counter % wl->num_rx_desc;
    u32 drv_rx_counter = wl->rx_counter % wl->num_rx_desc;
    u32 rx_counter;
    u32 pkt_len, align_pkt_len;
    u32 pkt_offset, des;
    u8 hlid;
    enum wl_rx_buf_align rx_align;
    int ret = 0;

    while (drv_rx_counter != fw_rx_counter) {
        buf_size = 0;
        rx_counter = drv_rx_counter;
        while (rx_counter != fw_rx_counter) {
            des = le32_to_cpu(status->rx_pkt_descs[rx_counter]);
            pkt_len = wlcore_rx_get_buf_size(wl, des);
            align_pkt_len = wlcore_rx_get_align_buf_size(wl,
                                     pkt_len);
            if (buf_size + align_pkt_len > wl->aggr_buf_size)
                break;
            buf_size += align_pkt_len;
            rx_counter++;
            rx_counter %= wl->num_rx_desc;
        }

        if (buf_size == 0) {
            wl1271_warning("received empty data");
            break;
        }

        /* Read all available packets at once */
        des = le32_to_cpu(status->rx_pkt_descs[drv_rx_counter]);
        ret = wlcore_hw_prepare_read(wl, des, buf_size);
        if (ret < 0)
            goto out;

        ret = wlcore_read_data(wl, REG_SLV_MEM_DATA, wl->aggr_buf,
                       buf_size, true);
        if (ret < 0)
            goto out;

        /* Split data into separate packets */
        pkt_offset = 0;
        while (pkt_offset < buf_size) {
            des = le32_to_cpu(status->rx_pkt_descs[drv_rx_counter]);
            pkt_len = wlcore_rx_get_buf_size(wl, des);
            rx_align = wlcore_hw_get_rx_buf_align(wl, des);

            /*
             * the handle data call can only fail in memory-outage
             * conditions, in that case the received frame will just
             * be dropped.
             */
            if (wl1271_rx_handle_data(wl,
                          wl->aggr_buf + pkt_offset,
                          pkt_len, rx_align,
                          &hlid) == 1) {
                if (hlid < WL12XX_MAX_LINKS)
                    __set_bit(hlid, active_hlids);
                else
                    WARN(1,
                         "hlid exceeded WL12XX_MAX_LINKS "
                         "(%d)\n", hlid);
            }

            wl->rx_counter++;
            drv_rx_counter++;
            drv_rx_counter %= wl->num_rx_desc;
            pkt_offset += wlcore_rx_get_align_buf_size(wl, pkt_len);
        }
    }

    /*
     * Write the driver's packet counter to the FW. This is only required
     * for older hardware revisions
     */
    if (wl->quirks & WLCORE_QUIRK_END_OF_TRANSACTION) {
        ret = wlcore_write32(wl, WL12XX_REG_RX_DRIVER_COUNTER,
                     wl->rx_counter);
        if (ret < 0)
            goto out;
    }

    wl12xx_rearm_rx_streaming(wl, active_hlids);

out:
    return ret;
}

#ifdef CONFIG_PM
int wl1271_rx_filter_enable(struct wl1271 *wl,
                int index, bool enable,
                struct wl12xx_rx_filter *filter)
{
    int ret;

    if (wl->rx_filter_enabled[index] == enable) {
        wl1271_warning("Request to enable an already "
                 "enabled rx filter %d", index);
        return 0;
    }

    ret = wl1271_acx_set_rx_filter(wl, index, enable, filter);

    if (ret) {
        wl1271_error("Failed to %s rx data filter %d (err=%d)",
                 enable ? "enable" : "disable", index, ret);
        return ret;
    }

    wl->rx_filter_enabled[index] = enable;

    return 0;
}

int wl1271_rx_filter_clear_all(struct wl1271 *wl)
{
    int i, ret = 0;

    for (i = 0; i < WL1271_MAX_RX_FILTERS; i++) {
        if (!wl->rx_filter_enabled[i])
            continue;
        ret = wl1271_rx_filter_enable(wl, i, 0, NULL);
        if (ret)
            goto out;
    }

out:
    return ret;
}
#endif /* CONFIG_PM */