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mt76: mt7921: add .set_sar_specs support

PATCH [email protected] 2 participants 2 messages Jun 21, 2021 – Jun 22, 2021 1 message not in the archive Arm MediaTek

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#1 lore raw

From: Sean Wang <[email protected]>

Quoted 57 lines
Quoted 57 lines

From: YN Chen <[email protected]>

add .set_sar_specs to allow configuring SAR power limitations on the frequency ranges from the userland.

Co-developed-by Sean Wang <[email protected]>
Signed-off-by Sean Wang <[email protected]>
Signed-off-by YN Chen <[email protected]>
---
 drivers/net/wireless/mediatek/mt76/mt76.h     |  3 ++
 .../net/wireless/mediatek/mt76/mt76_connac.h  |  5 +++
.../wireless/mediatek/mt76/mt76_connac_mcu.c  | 24 +++++++++-
.../net/wireless/mediatek/mt76/mt7921/init.c  | 21 +++++++++
.../net/wireless/mediatek/mt76/mt7921/main.c  | 45 +++++++++++++++++++
 5 files changed, 97 insertions(+), 1 deletion(-)
drivers/net/wireless/mediatek/mt76/mt76.h +3 -0
index 25c5ceef5257..63ce5242c4d5 100644
@@ -636,6 +636,9 @@ struct mt76_phy {
 		struct sk_buff **tail;
 		u16 seqno;
 	} rx_amsdu[__MT_RXQ_MAX];
+
+	void *frp_data;
+	u8 num_frps;
 };
 
 struct mt76_dev {
drivers/net/wireless/mediatek/mt76/mt76_connac.h +5 -0
index f49d97d0a1c5..95c7d1cac7c4 100644
@@ -83,6 +83,11 @@ struct mt76_connac_coredump {
 	unsigned long last_activity;
 };
 
+struct mt76_connac_freq_range_power {
+	const struct cfg80211_sar_freq_ranges *range;
+	s8 power;
+};
+
 extern const struct wiphy_wowlan_support mt76_connac_wowlan_support;
 
 static inline bool is_mt7921(struct mt76_dev *dev) diff --git

a/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c b/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c index 5c3a81e5f559..07f45cb4f500 100644

drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c +0 -0
@@ -1749,6 +1749,24 @@ mt76_connac_mcu_build_sku(struct mt76_dev *dev, s8 *sku,
 	}
 }
Quoted 15 lines

drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c mt76_connac_mcu_build_sku(struct mt76_dev *dev, s8 *sku, · line 1764

Quoted 13 lines
drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c +13 -0
+static s8 mt76_connac_get_sar_power(struct mt76_phy *phy,
+				    struct ieee80211_channel *chan,
+				    s8 target_power)
+{
+	struct mt76_connac_freq_range_power *frp = phy->frp_data;
+	int freq, i;
+
+	freq = ieee80211_channel_to_frequency(chan->hw_value, chan->band);
+	for (i = 0 ; i < phy->num_frps; i++) {
+		if (frp[i].range &&
+		    freq >= frp[i].range->start_freq &&
+		    freq < frp[i].range->end_freq)
+			target_power = min_t(s8, frp[i].power, target_power);

can we have overlapping freq range? if not I guess you can add a break here.

It is supposed to be there is no overlapping freq range for the real use case. I will add a break in the next version.

Quoted 54 lines
Quoted 54 lines
drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c +10 -1
+	}
+
+	return target_power;
+}
+
 static int
 mt76_connac_mcu_rate_txpower_band(struct mt76_phy *phy,
 				  enum nl80211_band band)

@@ -1816,9 +1834,13 @@ mt76_connac_mcu_rate_txpower_band(struct mt76_phy *phy,
 				.hw_value = ch_list[idx],
 				.band = band,
 			};
+			s8 sar_power;
+
+			sar_power = mt76_connac_get_sar_power(phy, &chan,
+							      tx_power);
 
 			mt76_get_rate_power_limits(phy, &chan, &limits,
-						   tx_power);
+						   sar_power);
 
 			tx_power_tlv.last_msg = ch_list[idx] == last_ch;
 			sku_tlbv.channel = ch_list[idx];
drivers/net/wireless/mediatek/mt76/mt7921/init.c +12 -0
index a9ce10b98827..e7f66d988a49 100644
@@ -24,6 +24,20 @@ static const struct ieee80211_iface_combination if_comb[] = {
 	}
 };
 
+const struct cfg80211_sar_freq_ranges mt7921_sar_freq_ranges[] = {
+	{ .start_freq = 2402, .end_freq = 2494, },
+	{ .start_freq = 5150, .end_freq = 5350, },
+	{ .start_freq = 5350, .end_freq = 5470, },
+	{ .start_freq = 5470, .end_freq = 5725, },
+	{ .start_freq = 5725, .end_freq = 5950, }, };
+
+static const struct cfg80211_sar_capa mt7921_sar_capa = {
+	.type = NL80211_SAR_TYPE_POWER,
+	.num_freq_ranges = ARRAY_SIZE(mt7921_sar_freq_ranges),
+	.freq_ranges = &mt7921_sar_freq_ranges[0], };
+
 static void
 mt7921_regd_notifier(struct wiphy *wiphy,
 		     struct regulatory_request *request) @@ -75,6 +89,13 @@

mt7921_init_wiphy(struct ieee80211_hw *hw)

	wiphy->max_sched_scan_reqs = 1;
	wiphy->flags |= WIPHY_FLAG_HAS_CHANNEL_SWITCH;
	wiphy->reg_notifier = mt7921_regd_notifier;
drivers/net/wireless/mediatek/mt76/mt7921/init.c +1 -0
+	wiphy->sar_capa = &mt7921_sar_capa;
Quoted 8 lines

drivers/net/wireless/mediatek/mt76/mt7921/init.c

Quoted 5 lines
drivers/net/wireless/mediatek/mt76/mt7921/init.c +5 -0
+
+	phy->mt76->frp_data = devm_kcalloc(dev->mt76.dev,
+					   wiphy->sar_capa->num_freq_ranges,
+					   sizeof(struct mt76_connac_freq_range_power),
+					   GFP_KERNEL);

Here I guess we need to check if devm_kcalloc fails returning an int from mt7921_init_wiphy()

Sure, will do it.

Quoted 23 lines
Quoted 23 lines
drivers/net/wireless/mediatek/mt76/mt7921/init.c +1 -0
+	phy->mt76->num_frps = wiphy->sar_capa->num_freq_ranges;

	wiphy->features |= NL80211_FEATURE_SCHED_SCAN_RANDOM_MAC_ADDR |
			   NL80211_FEATURE_SCAN_RANDOM_MAC_ADDR;
drivers/net/wireless/mediatek/mt76/mt7921/main.c +10 -0
index 7fd21049ff5a..e9b5d79e139f 100644
@@ -1171,6 +1171,50 @@ static void mt7921_sta_set_decap_offload(struct ieee80211_hw *hw,
 					     MCU_UNI_CMD_STA_REC_UPDATE);  }
 
+static int mt7921_set_sar_specs(struct ieee80211_hw *hw,
+				const struct cfg80211_sar_specs *sar) {
+	const struct cfg80211_sar_capa *capa = hw->wiphy->sar_capa;
+	struct mt76_connac_freq_range_power *frp_data, *frp;
+	struct mt7921_dev *dev = mt7921_hw_dev(hw);
+	struct mt76_phy *mphy = hw->priv;
+	int err;
+	u32 i;
+
+	mt7921_mutex_acquire(dev);
Quoted 9 lines

drivers/net/wireless/mediatek/mt76/mt7921/main.c static void mt7921_sta_set_decap_offload(struct ieee80211_hw *hw, · line 1188

Quoted 6 lines
drivers/net/wireless/mediatek/mt76/mt7921/main.c +6 -0
+
+	if (!sar || sar->type != NL80211_SAR_TYPE_POWER ||
+	    sar->num_sub_specs == 0) {
+		err = -EINVAL;
+		goto out;
+	}

I guess you can move this out of the lock

Sure, will do it.

Quoted 10 lines
Quoted 10 lines
drivers/net/wireless/mediatek/mt76/mt7921/main.c +10 -0
+
+	frp_data = mphy->frp_data;
+
+	for (i = 0; i < sar->num_sub_specs; i++) {
+		u32 index = sar->sub_specs[i].freq_range_index;
+		/* SAR specifies power limitaton in 0.25dbm */
+		s32 power = sar->sub_specs[i].power >> 1;
+
+		if (power > 127 || power < -127)
+			power = 127;
Quoted 9 lines

drivers/net/wireless/mediatek/mt76/mt7921/main.c static void mt7921_sta_set_decap_offload(struct ieee80211_hw *hw, · line 1204

Quoted 6 lines
drivers/net/wireless/mediatek/mt76/mt7921/main.c +6 -0
+
+		if (index >= mphy->num_frps)
+			continue;
+
+		frp = &frp_data[index];
+		frp->range = &capa->freq_ranges[index];

I guess there is an use-after-free here since sar is freed at the end of nl80211_set_sar_specs, right?

Nope, there is no use-after-free case happens here because frp->range just points to an entry of const struct cfg80211_sar_specs table, not the one created from nl80211_set_sar_specs.

Quoted 17 lines

Regards,
Lorenzo

Quoted 14 lines
drivers/net/wireless/mediatek/mt76/mt7921/main.c +11 -0
+		frp->power = power;
+	}
+
+	err = mt76_connac_mcu_set_rate_txpower(mphy);
+
+out:
+	mt7921_mutex_release(dev);
+
+	return err;
+}
+
 const struct ieee80211_ops mt7921_ops = {
 	.tx = mt7921_tx,
 	.start = mt7921_start,
Quoted 8 lines
Quoted 8 lines
drivers/net/wireless/mediatek/mt76/mt7921/main.c +1 -1
@@ -1209,4 +1253,5 @@ const struct ieee80211_ops mt7921_ops = {
 	.set_rekey_data = mt7921_set_rekey_data,  #endif /* CONFIG_PM */
 	.flush = mt7921_flush,
+	.set_sar_specs = mt7921_set_sar_specs,
 };
--

2.25.1

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#2 lore raw

[...]

Quoted 5 lines
Quoted 3 lines

I guess there is an use-after-free here since sar is freed at the end of nl80211_set_sar_specs, right?

Nope, there is no use-after-free case happens here because frp->range just points to an entry of const struct cfg80211_sar_specs table, not the one created from nl80211_set_sar_specs.

ack, right. I misread the code.

Regards,
Lorenzo

Quoted 26 lines
Quoted 26 lines

Regards,
Lorenzo

Quoted 22 lines
(quoted diff) +11 -0
+		frp->power = power;
+	}
+
+	err = mt76_connac_mcu_set_rate_txpower(mphy);
+
+out:
+	mt7921_mutex_release(dev);
+
+	return err;
+}
+
 const struct ieee80211_ops mt7921_ops = {

	.tx = mt7921_tx,
	.start = mt7921_start,
(quoted diff) +1 -1
@@ -1209,4 +1253,5 @@ const struct ieee80211_ops mt7921_ops = {
 	.set_rekey_data = mt7921_set_rekey_data,  #endif /* CONFIG_PM */
 	.flush = mt7921_flush,
+	.set_sar_specs = mt7921_set_sar_specs,
 };
--

2.25.1