iwlwifi: Thermal Throttling Management - part 2

Part 2 of Thermal Throttling Management -

Thermal Throttling feature is used to put NIC into low power state when
driver detect the Radio temperature reach pre-defined threshold

Two Thermal Throttling Management Methods; this patch introduce the
Advance Thermal Throttling:
TI-0: system power index, no tx/rx restriction, HT enabled
TI-1: power index 5, 1 spatial stream Tx, multiple spatial stream Rx, HT
enabled
TI-2: power index 5: 1 spatial stream Tx, 1 spatial stream Rx, HT
disabled
TI-CT-KILL: power index 5, no Tx, no Rx, HT disabled

For advance Thermal Throttling, CT_KILL_ENTER threshold and CT_KILL_EXIT
threshold are different; uCode will not stay awake until reach
CT_KILL_EXIT threshold.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 281 insertions, 4 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-power.c b/drivers/net/wireless/iwlwifi/iwl-power.c
index d7fdb582545..00937b3ee8e 100644
--- a/drivers/net/wireless/iwlwifi/iwl-power.c
+++ b/drivers/net/wireless/iwlwifi/iwl-power.c
@@ -98,6 +98,45 @@ static const struct iwl_power_vec_entry range_2[IWL_POWER_NUM] = {
 	{{SLP, SLP_TOUT(25), SLP_TOUT(25), SLP_VEC(4, 7, 10, 10, 0xFF)}, 0}
 };
 
+/* default Thermal Throttling transaction table
+ * Current state   |         Throttling Down               |  Throttling Up
+ *=============================================================================
+ *                 Condition Nxt State  Condition Nxt State Condition Nxt State
+ *-----------------------------------------------------------------------------
+ *     IWL_TI_0     T >= 115   CT_KILL  115>T>=105   TI_1      N/A      N/A
+ *     IWL_TI_1     T >= 115   CT_KILL  115>T>=110   TI_2     T<=95     TI_0
+ *     IWL_TI_2     T >= 115   CT_KILL                        T<=100    TI_1
+ *    IWL_CT_KILL      N/A       N/A       N/A        N/A     T<=95     TI_0
+ *=============================================================================
+ */
+static const struct iwl_tt_trans tt_range_0[IWL_TI_STATE_MAX - 1] = {
+	{IWL_TI_0, IWL_ABSOLUTE_ZERO, 104},
+	{IWL_TI_1, 105, CT_KILL_THRESHOLD},
+	{IWL_TI_CT_KILL, CT_KILL_THRESHOLD + 1, IWL_ABSOLUTE_MAX}
+};
+static const struct iwl_tt_trans tt_range_1[IWL_TI_STATE_MAX - 1] = {
+	{IWL_TI_0, IWL_ABSOLUTE_ZERO, 95},
+	{IWL_TI_2, 110, CT_KILL_THRESHOLD},
+	{IWL_TI_CT_KILL, CT_KILL_THRESHOLD + 1, IWL_ABSOLUTE_MAX}
+};
+static const struct iwl_tt_trans tt_range_2[IWL_TI_STATE_MAX - 1] = {
+	{IWL_TI_1, IWL_ABSOLUTE_ZERO, 100},
+	{IWL_TI_CT_KILL, CT_KILL_THRESHOLD + 1, IWL_ABSOLUTE_MAX},
+	{IWL_TI_CT_KILL, CT_KILL_THRESHOLD + 1, IWL_ABSOLUTE_MAX}
+};
+static const struct iwl_tt_trans tt_range_3[IWL_TI_STATE_MAX - 1] = {
+	{IWL_TI_0, IWL_ABSOLUTE_ZERO, CT_KILL_EXIT_THRESHOLD},
+	{IWL_TI_CT_KILL, CT_KILL_EXIT_THRESHOLD + 1, IWL_ABSOLUTE_MAX},
+	{IWL_TI_CT_KILL, CT_KILL_EXIT_THRESHOLD + 1, IWL_ABSOLUTE_MAX}
+};
+
+/* Advance Thermal Throttling default restriction table */
+static const struct iwl_tt_restriction restriction_range[IWL_TI_STATE_MAX] = {
+	{IWL_TX_MULTI, true, IWL_RX_MULTI},
+	{IWL_TX_SINGLE, true, IWL_RX_MULTI},
+	{IWL_TX_SINGLE, false, IWL_RX_SINGLE},
+	{IWL_TX_NONE, false, IWL_RX_NONE}
+};
 
 /* set card power command */
 static int iwl_set_power(struct iwl_priv *priv, void *cmd)
@@ -273,6 +312,42 @@ int iwl_power_set_user_mode(struct iwl_priv *priv, u16 mode)
 }
 EXPORT_SYMBOL(iwl_power_set_user_mode);
 
+bool iwl_ht_enabled(struct iwl_priv *priv)
+{
+	struct iwl_tt_mgmt *tt = &priv->power_data.tt;
+	struct iwl_tt_restriction *restriction;
+
+	if (!priv->power_data.adv_tt)
+		return true;
+	restriction = tt->restriction + tt->state;
+	return restriction->is_ht;
+}
+EXPORT_SYMBOL(iwl_ht_enabled);
+
+u8 iwl_tx_ant_restriction(struct iwl_priv *priv)
+{
+	struct iwl_tt_mgmt *tt = &priv->power_data.tt;
+	struct iwl_tt_restriction *restriction;
+
+	if (!priv->power_data.adv_tt)
+		return IWL_TX_MULTI;
+	restriction = tt->restriction + tt->state;
+	return restriction->tx_stream;
+}
+EXPORT_SYMBOL(iwl_tx_ant_restriction);
+
+u8 iwl_rx_ant_restriction(struct iwl_priv *priv)
+{
+	struct iwl_tt_mgmt *tt = &priv->power_data.tt;
+	struct iwl_tt_restriction *restriction;
+
+	if (!priv->power_data.adv_tt)
+		return IWL_RX_MULTI;
+	restriction = tt->restriction + tt->state;
+	return restriction->rx_stream;
+}
+EXPORT_SYMBOL(iwl_rx_ant_restriction);
+
 #define CT_KILL_EXIT_DURATION (5)	/* 5 seconds duration */
 
 /*
@@ -427,12 +502,147 @@ static void iwl_legacy_tt_handler(struct iwl_priv *priv, s32 temp)
 	}
 }
 
+/*
+ * Advance thermal throttling
+ * 1) Avoid NIC destruction due to high temperatures
+ *	Chip will identify dangerously high temperatures that can
+ *	harm the device and will power down
+ * 2) Avoid the NIC power down due to high temperature
+ *	Throttle early enough to lower the power consumption before
+ *	drastic steps are needed
+ *	Actions include relaxing the power down sleep thresholds and
+ *	decreasing the number of TX streams
+ * 3) Avoid throughput performance impact as much as possible
+ *
+ *=============================================================================
+ *                 Condition Nxt State  Condition Nxt State Condition Nxt State
+ *-----------------------------------------------------------------------------
+ *     IWL_TI_0     T >= 115   CT_KILL  115>T>=105   TI_1      N/A      N/A
+ *     IWL_TI_1     T >= 115   CT_KILL  115>T>=110   TI_2     T<=95     TI_0
+ *     IWL_TI_2     T >= 115   CT_KILL                        T<=100    TI_1
+ *    IWL_CT_KILL      N/A       N/A       N/A        N/A     T<=95     TI_0
+ *=============================================================================
+ */
+static void iwl_advance_tt_handler(struct iwl_priv *priv, s32 temp)
+{
+	struct iwl_tt_mgmt *tt = &priv->power_data.tt;
+	int i;
+	bool changed = false;
+	enum iwl_tt_state old_state;
+	struct iwl_tt_trans *transaction;
+
+	old_state = tt->state;
+	for (i = 0; i < IWL_TI_STATE_MAX - 1; i++) {
+		/* based on the current TT state,
+		 * find the curresponding transaction table
+		 * each table has (IWL_TI_STATE_MAX - 1) entries
+		 * tt->transaction + ((old_state * (IWL_TI_STATE_MAX - 1))
+		 * will advance to the correct table.
+		 * then based on the current temperature
+		 * find the next state need to transaction to
+		 * go through all the possible (IWL_TI_STATE_MAX - 1) entries
+		 * in the current table to see if transaction is needed
+		 */
+		transaction = tt->transaction +
+			((old_state * (IWL_TI_STATE_MAX - 1)) + i);
+		if (temp >= transaction->tt_low &&
+		    temp <= transaction->tt_high) {
+#ifdef CONFIG_IWLWIFI_DEBUG
+			if ((tt->tt_previous_temp) &&
+			    (temp > tt->tt_previous_temp) &&
+			    ((temp - tt->tt_previous_temp) >
+			    IWL_TT_INCREASE_MARGIN)) {
+				IWL_DEBUG_POWER(priv,
+					"Temperature increase %d "
+					"degree Celsius\n",
+					(temp - tt->tt_previous_temp));
+			}
+			tt->tt_previous_temp = temp;
+#endif
+			if (old_state !=
+			    transaction->next_state) {
+				changed = true;
+				tt->state =
+					transaction->next_state;
+			}
+			break;
+		}
+	}
+	if (changed) {
+		struct iwl_rxon_cmd *rxon = &priv->staging_rxon;
+		struct iwl_power_mgr *setting = &priv->power_data;
+
+		if (tt->state >= IWL_TI_1) {
+			/* if switching from IWL_TI_0 to other TT state
+			 * save previous power setting in tt->sys_power_mode */
+			if (old_state == IWL_TI_0)
+				tt->sys_power_mode = setting->power_mode;
+			/* force PI = IWL_POWER_INDEX_5 in the case of TI > 0 */
+			tt->tt_power_mode = IWL_POWER_INDEX_5;
+			if (!iwl_ht_enabled(priv))
+				/* disable HT */
+				rxon->flags &= ~(RXON_FLG_CHANNEL_MODE_MSK |
+					RXON_FLG_CTRL_CHANNEL_LOC_HI_MSK |
+					RXON_FLG_FAT_PROT_MSK |
+					RXON_FLG_HT_PROT_MSK);
+			else {
+				/* check HT capability and set
+				 * according to the system HT capability
+				 * in case get disabled before */
+				iwl_set_rxon_ht(priv, &priv->current_ht_config);
+			}
+
+		} else {
+			/* restore system power setting */
+			/* the previous power mode was saved in
+			 * tt->sys_power_mode when system move into
+			 * Thermal Throttling state
+			 * set power_data.user_power_setting to the previous
+			 * system power mode to make sure power will get
+			 * updated correctly
+			 */
+			priv->power_data.user_power_setting =
+				tt->sys_power_mode;
+			tt->tt_power_mode = tt->sys_power_mode;
+			/* check HT capability and set
+			 * according to the system HT capability
+			 * in case get disabled before */
+			iwl_set_rxon_ht(priv, &priv->current_ht_config);
+		}
+		if (iwl_power_update_mode(priv, true)) {
+			/* TT state not updated
+			 * try again during next temperature read
+			 */
+			IWL_ERR(priv, "Cannot update power mode, "
+					"TT state not updated\n");
+			tt->state = old_state;
+		} else {
+			IWL_DEBUG_POWER(priv,
+					"Thermal Throttling to new state: %u\n",
+					tt->state);
+			if (old_state != IWL_TI_CT_KILL &&
+			    tt->state == IWL_TI_CT_KILL) {
+				IWL_DEBUG_POWER(priv, "Enter IWL_TI_CT_KILL\n");
+				iwl_perform_ct_kill_task(priv, true);
+
+			} else if (old_state == IWL_TI_CT_KILL &&
+				  tt->state != IWL_TI_CT_KILL) {
+				IWL_DEBUG_POWER(priv, "Exit IWL_TI_CT_KILL\n");
+				iwl_perform_ct_kill_task(priv, false);
+			}
+		}
+	}
+}
+
 /* Card State Notification indicated reach critical temperature
  * if PSP not enable, no Thermal Throttling function will be performed
  * just set the GP1 bit to acknowledge the event
  * otherwise, go into IWL_TI_CT_KILL state
  * since Card State Notification will not provide any temperature reading
+ * for Legacy mode
  * so just pass the CT_KILL temperature to iwl_legacy_tt_handler()
+ * for advance mode
+ * pass CT_KILL_THRESHOLD+1 to make sure move into IWL_TI_CT_KILL state
  */
 void iwl_tt_enter_ct_kill(struct iwl_priv *priv)
 {
@@ -444,7 +654,12 @@ void iwl_tt_enter_ct_kill(struct iwl_priv *priv)
 	if (tt->state != IWL_TI_CT_KILL) {
 		IWL_ERR(priv, "Device reached critical temperature "
 			      "- ucode going to sleep!\n");
-		iwl_legacy_tt_handler(priv, IWL_MINIMAL_POWER_THRESHOLD);
+		if (!priv->power_data.adv_tt)
+			iwl_legacy_tt_handler(priv,
+					      IWL_MINIMAL_POWER_THRESHOLD);
+		else
+			iwl_advance_tt_handler(priv,
+					       CT_KILL_THRESHOLD + 1);
 	}
 }
 EXPORT_SYMBOL(iwl_tt_enter_ct_kill);
@@ -468,8 +683,11 @@ void iwl_tt_exit_ct_kill(struct iwl_priv *priv)
 		IWL_ERR(priv,
 			"Device temperature below critical"
 			"- ucode awake!\n");
-		iwl_legacy_tt_handler(priv,
-			IWL_REDUCED_PERFORMANCE_THRESHOLD_2);
+		if (!priv->power_data.adv_tt)
+			iwl_legacy_tt_handler(priv,
+					IWL_REDUCED_PERFORMANCE_THRESHOLD_2);
+		else
+			iwl_advance_tt_handler(priv, CT_KILL_EXIT_THRESHOLD);
 	}
 }
 EXPORT_SYMBOL(iwl_tt_exit_ct_kill);
@@ -484,16 +702,24 @@ void iwl_tt_handler(struct iwl_priv *priv)
 	if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
 		temp = KELVIN_TO_CELSIUS(priv->temperature);
 
-	iwl_legacy_tt_handler(priv, temp);
+	if (!priv->power_data.adv_tt)
+		iwl_legacy_tt_handler(priv, temp);
+	else
+		iwl_advance_tt_handler(priv, temp);
 }
 EXPORT_SYMBOL(iwl_tt_handler);
 
 /* Thermal throttling initialization
+ * For advance thermal throttling:
+ *     Initialize Thermal Index and temperature threshold table
+ *     Initialize thermal throttling restriction table
  */
 void iwl_tt_initialize(struct iwl_priv *priv)
 {
 	struct iwl_tt_mgmt *tt = &priv->power_data.tt;
 	struct iwl_power_mgr *setting = &priv->power_data;
+	int size = sizeof(struct iwl_tt_trans) * (IWL_TI_STATE_MAX - 1);
+	struct iwl_tt_trans *transaction;
 
 	IWL_DEBUG_POWER(priv, "Initialize Thermal Throttling \n");
 
@@ -505,14 +731,65 @@ void iwl_tt_initialize(struct iwl_priv *priv)
 	init_timer(&priv->power_data.ct_kill_exit_tm);
 	priv->power_data.ct_kill_exit_tm.data = (unsigned long)priv;
 	priv->power_data.ct_kill_exit_tm.function = iwl_tt_check_exit_ct_kill;
+	switch (priv->hw_rev & CSR_HW_REV_TYPE_MSK) {
+	case CSR_HW_REV_TYPE_6x00:
+	case CSR_HW_REV_TYPE_6x50:
+		IWL_DEBUG_POWER(priv, "Advanced Thermal Throttling\n");
+		tt->restriction = kzalloc(sizeof(struct iwl_tt_restriction) *
+					 IWL_TI_STATE_MAX, GFP_KERNEL);
+		tt->transaction = kzalloc(sizeof(struct iwl_tt_trans) *
+			IWL_TI_STATE_MAX * (IWL_TI_STATE_MAX - 1),
+			GFP_KERNEL);
+		if (!tt->restriction || !tt->transaction) {
+			IWL_ERR(priv, "Fallback to Legacy Throttling\n");
+			priv->power_data.adv_tt = false;
+			kfree(tt->restriction);
+			tt->restriction = NULL;
+			kfree(tt->transaction);
+			tt->transaction = NULL;
+		} else {
+			transaction = tt->transaction +
+				(IWL_TI_0 * (IWL_TI_STATE_MAX - 1));
+			memcpy(transaction, &tt_range_0[0], size);
+			transaction = tt->transaction +
+				(IWL_TI_1 * (IWL_TI_STATE_MAX - 1));
+			memcpy(transaction, &tt_range_1[0], size);
+			transaction = tt->transaction +
+				(IWL_TI_2 * (IWL_TI_STATE_MAX - 1));
+			memcpy(transaction, &tt_range_2[0], size);
+			transaction = tt->transaction +
+				(IWL_TI_CT_KILL * (IWL_TI_STATE_MAX - 1));
+			memcpy(transaction, &tt_range_3[0], size);
+			size = sizeof(struct iwl_tt_restriction) *
+				IWL_TI_STATE_MAX;
+			memcpy(tt->restriction,
+				&restriction_range[0], size);
+			priv->power_data.adv_tt = true;
+		}
+		break;
+	default:
+		IWL_DEBUG_POWER(priv, "Legacy Thermal Throttling\n");
+		priv->power_data.adv_tt = false;
+		break;
+	}
 }
 EXPORT_SYMBOL(iwl_tt_initialize);
 
 /* cleanup thermal throttling management related memory and timer */
 void iwl_tt_exit(struct iwl_priv *priv)
 {
+	struct iwl_tt_mgmt *tt = &priv->power_data.tt;
+
 	/* stop ct_kill_exit_tm timer if activated */
 	del_timer_sync(&priv->power_data.ct_kill_exit_tm);
+
+	if (priv->power_data.adv_tt) {
+		/* free advance thermal throttling memory */
+		kfree(tt->restriction);
+		tt->restriction = NULL;
+		kfree(tt->transaction);
+		tt->transaction = NULL;
+	}
 }
 EXPORT_SYMBOL(iwl_tt_exit);