path: root/drivers/net/wireless/intel/iwlwifi/dvm/calib.c

// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
 * Copyright (C) 2005-2014 Intel Corporation
 */
#include <linux/slab.h>
#include <net/mac80211.h>

#include "iwl-trans.h"

#include "dev.h"
#include "calib.h"
#include "agn.h"

/*****************************************************************************
 * INIT calibrations framework
 *****************************************************************************/

/* Opaque calibration results */
struct iwl_calib_result {
	struct list_head list;
	size_t cmd_len;
	struct iwl_calib_cmd cmd;
};

struct statistics_general_data {
	u32 beacon_silence_rssi_a;
	u32 beacon_silence_rssi_b;
	u32 beacon_silence_rssi_c;
	u32 beacon_energy_a;
	u32 beacon_energy_b;
	u32 beacon_energy_c;
};

int iwl_send_calib_results(struct iwl_priv *priv)
{
	struct iwl_host_cmd hcmd = {
		.id = REPLY_PHY_CALIBRATION_CMD,
	};
	struct iwl_calib_result *res;

	list_for_each_entry(res, &priv->calib_results, list) {
		int ret;

		hcmd.len[0] = res->cmd_len;
		hcmd.data[0] = &res->cmd;
		hcmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
		ret = iwl_dvm_send_cmd(priv, &hcmd);
		if (ret) {
			IWL_ERR(priv, "Error %d on calib cmd %d\n",
				ret, res->cmd.hdr.op_code);
			return ret;
		}
	}

	return 0;
}

int iwl_calib_set(struct iwl_priv *priv,
		  const struct iwl_calib_cmd *cmd, size_t len)
{
	struct iwl_calib_result *res, *tmp;

	if (check_sub_overflow(len, sizeof(*cmd), &len))
		return -ENOMEM;

	res = kmalloc(struct_size(res, cmd.data, len), GFP_ATOMIC);
	if (!res)
		return -ENOMEM;
	res->cmd = *cmd;
	memcpy(res->cmd.data, cmd->data, len);
	res->cmd_len = struct_size(cmd, data, len);

	list_for_each_entry(tmp, &priv->calib_results, list) {
		if (tmp->cmd.hdr.op_code == res->cmd.hdr.op_code) {
			list_replace(&tmp->list, &res->list);
			kfree(tmp);
			return 0;
		}
	}

	/* wasn't in list already */
	list_add_tail(&res->list, &priv->calib_results);

	return 0;
}

void iwl_calib_free_results(struct iwl_priv *priv)
{
	struct iwl_calib_result *res, *tmp;

	list_for_each_entry_safe(res, tmp, &priv->calib_results, list) {
		list_del(&res->list);
		kfree(res);
	}
}

/*****************************************************************************
 * RUNTIME calibrations framework
 *****************************************************************************/

/* "false alarms" are signals that our DSP tries to lock onto,
 *   but then determines that they are either noise, or transmissions
 *   from a distant wireless network (also "noise", really) that get
 *   "stepped on" by stronger transmissions within our own network.
 * This algorithm attempts to set a sensitivity level that is high
 *   enough to receive all of our own network traffic, but not so
 *   high that our DSP gets too busy trying to lock onto non-network
 *   activity/noise. */
static int iwl_sens_energy_cck(struct iwl_priv *priv,
				   u32 norm_fa,
				   u32 rx_enable_time,
				   struct statistics_general_data *rx_info)
{
	u32 max_nrg_cck = 0;
	int i = 0;
	u8 max_silence_rssi = 0;
	u32 silence_ref = 0;
	u8 silence_rssi_a = 0;
	u8 silence_rssi_b = 0;
	u8 silence_rssi_c = 0;
	u32 val;

	/* "false_alarms" values below are cross-multiplications to assess the
	 *   numbers of false alarms within the measured period of actual Rx
	 *   (Rx is off when we're txing), vs the min/max expected false alarms
	 *   (some should be expected if rx is sensitive enough) in a
	 *   hypothetical listening period of 200 time units (TU), 204.8 msec:
	 *
	 * MIN_FA/fixed-time < false_alarms/actual-rx-time < MAX_FA/beacon-time
	 *
	 * */
	u32 false_alarms = norm_fa * 200 * 1024;
	u32 max_false_alarms = MAX_FA_CCK * rx_enable_time;
	u32 min_false_alarms = MIN_FA_CCK * rx_enable_time;
	struct iwl_sensitivity_data *data = NULL;
	const struct iwl_sensitivity_ranges *ranges = priv->hw_params.sens;

	data = &(priv->sensitivity_data);

	data->nrg_auto_corr_silence_diff = 0;

	/* Find max silence rssi among all 3 receivers.
	 * This is background noise, which may include transmissions from other
	 *    networks, measured during silence before our network's beacon */
	silence_rssi_a = (u8)((rx_info->beacon_silence_rssi_a &
			    ALL_BAND_FILTER) >> 8);
	silence_rssi_b = (u8)((rx_info->beacon_silence_rssi_b &
			    ALL_BAND_FILTER) >> 8);
	silence_rssi_c = (u8)((rx_info->beacon_silence_rssi_c &
			    ALL_BAND_FILTER) >> 8);

	val = max(silence_rssi_b, silence_rssi_c);
	max_silence_rssi = max(silence_rssi_a, (u8) val);

	/* Store silence rssi in 20-beacon history table */
	data->nrg_silence_rssi[data->nrg_silence_idx] = max_silence_rssi;
	data->nrg_silence_idx++;
	if (data->nrg_silence_idx >= NRG_NUM_PREV_STAT_L)
		data->nrg_silence_idx = 0;

	/* Find max silence rssi across 20 beacon history */
	for (i = 0; i < NRG_NUM_PREV_STAT_L; i++) {
		val = data->nrg_silence_rssi[i];
		silence_ref = max(silence_ref, val);
	}
	IWL_DEBUG_CALIB(priv, "silence a %u, b %u, c %u, 20-bcn max %u\n",
			silence_rssi_a, silence_rssi_b