wifi: rtw89: refine packet offload delete flow of 6 GHz probe

There are two places where offload packets of 6 GHz probe would be deleted
from FW, i.e. calling rtw89_fw_h2c_del_pkt_offload().
* rtw89_core_cancel_6ghz_probe_tx()
* rtw89_release_pkt_list()
It is possible that we try to delete the same one from FW twice. Although
it might not be a big problem for now, it will depend on the runtime chip
firmware. So, we add a check to avoid it. In case things becomes complex
due to racing problem, we don't choose to do list_del(info->list) and
kfree(info) in both sides.

Besides, rtw89_fw_h2c_del_pkt_offload() will needs to wait for completion
after the follow-up commit. However, rtw89_core_cancel_6ghz_probe_tx()
was called in interrupt context. So, we move the stuffs of calling
rtw89_fw_h2c_del_pkt_offload() from rtw89_core_cancel_6ghz_probe_tx()
into a work. Then, we also need a check there before we call it.
Signed-off-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/091966e5709cd7caecf9b81f7fd6388ae2b70a7e.camel@realtek.com

drivers/net/wireless/realtek/rtw89/core.c

@@ -1515,6 +1515,34 @@ static void rtw89_stats_trigger_frame(struct rtw89_dev *rtwdev,
 	}
 }
 
+static void rtw89_cancel_6ghz_probe_work(struct work_struct *work)
+{
+	struct rtw89_dev *rtwdev = container_of(work, struct rtw89_dev,
+						cancel_6ghz_probe_work);
+	struct list_head *pkt_list = rtwdev->scan_info.pkt_list;
+	struct rtw89_pktofld_info *info;
+
+	mutex_lock(&rtwdev->mutex);
+
+	if (!rtwdev->scanning)
+		goto out;
+
+	list_for_each_entry(info, &pkt_list[NL80211_BAND_6GHZ], list) {
+		if (!info->cancel || !test_bit(info->id, rtwdev->pkt_offload))
+			continue;
+
+		rtw89_fw_h2c_del_pkt_offload(rtwdev, info->id);
+
+		/* Don't delete/free info from pkt_list at this moment. Let it
+		 * be deleted/freed in rtw89_release_pkt_list() after scanning,
+		 * since if during scanning, pkt_list is accessed in bottom half.
+		 */
+	}
+
+out:
+	mutex_unlock(&rtwdev->mutex);
+}
+
 static void rtw89_core_cancel_6ghz_probe_tx(struct rtw89_dev *rtwdev,
 					    struct sk_buff *skb)
 {
@@ -1523,6 +1551,7 @@ static void rtw89_core_cancel_6ghz_probe_tx(struct rtw89_dev *rtwdev,
 	struct list_head *pkt_list = rtwdev->scan_info.pkt_list;
 	struct rtw89_pktofld_info *info;
 	const u8 *ies = mgmt->u.beacon.variable, *ssid_ie;
+	bool queue_work = false;
 
 	if (rx_status->band != NL80211_BAND_6GHZ)
 		return;
@@ -1531,16 +1560,22 @@ static void rtw89_core_cancel_6ghz_probe_tx(struct rtw89_dev *rtwdev,
 
 	list_for_each_entry(info, &pkt_list[NL80211_BAND_6GHZ], list) {
 		if (ether_addr_equal(info->bssid, mgmt->bssid)) {
-			rtw89_fw_h2c_del_pkt_offload(rtwdev, info->id);
+			info->cancel = true;
+			queue_work = true;
 			continue;
 		}
 
 		if (!ssid_ie || ssid_ie[1] != info->ssid_len || info->ssid_len == 0)
 			continue;
 
-		if (memcmp(&ssid_ie[2], info->ssid, info->ssid_len) == 0)
-			rtw89_fw_h2c_del_pkt_offload(rtwdev, info->id);
+		if (memcmp(&ssid_ie[2], info->ssid, info->ssid_len) == 0) {
+			info->cancel = true;
+			queue_work = true;
+		}
 	}
+
+	if (queue_work)
+		ieee80211_queue_work(rtwdev->hw, &rtwdev->cancel_6ghz_probe_work);
 }
 
 static void rtw89_vif_rx_stats_iter(void *data, u8 *mac,
@@ -3474,6 +3509,7 @@ void rtw89_core_stop(struct rtw89_dev *rtwdev)
 	mutex_unlock(&rtwdev->mutex);
 
 	cancel_work_sync(&rtwdev->c2h_work);
+	cancel_work_sync(&rtwdev->cancel_6ghz_probe_work);
 	cancel_work_sync(&btc->eapol_notify_work);
 	cancel_work_sync(&btc->arp_notify_work);
 	cancel_work_sync(&btc->dhcp_notify_work);
@@ -3536,6 +3572,7 @@ int rtw89_core_init(struct rtw89_dev *rtwdev)
 	INIT_WORK(&rtwdev->c2h_work, rtw89_fw_c2h_work);
 	INIT_WORK(&rtwdev->ips_work, rtw89_ips_work);
 	INIT_WORK(&rtwdev->load_firmware_work, rtw89_load_firmware_work);
+	INIT_WORK(&rtwdev->cancel_6ghz_probe_work, rtw89_cancel_6ghz_probe_work);
 
 	skb_queue_head_init(&rtwdev->c2h_queue);
 	rtw89_core_ppdu_sts_init(rtwdev);

drivers/net/wireless/realtek/rtw89/core.h

@@ -4086,6 +4086,7 @@ struct rtw89_dev {
 	struct work_struct c2h_work;
 	struct work_struct ips_work;
 	struct work_struct load_firmware_work;
+	struct work_struct cancel_6ghz_probe_work;
 
 	struct list_head early_h2c_list;
 

drivers/net/wireless/realtek/rtw89/fw.c

@@ -3020,7 +3020,8 @@ static void rtw89_release_pkt_list(struct rtw89_dev *rtwdev)
 			continue;
 
 		list_for_each_entry_safe(info, tmp, &pkt_list[idx], list) {
-			rtw89_fw_h2c_del_pkt_offload(rtwdev, info->id);
+			if (test_bit(info->id, rtwdev->pkt_offload))
+				rtw89_fw_h2c_del_pkt_offload(rtwdev, info->id);
 			list_del(&info->list);
 			kfree(info);
 		}

drivers/net/wireless/realtek/rtw89/fw.h

@@ -277,6 +277,7 @@ struct rtw89_pktofld_info {
 	u8 ssid_len;
 	u8 bssid[ETH_ALEN];
 	u16 channel_6ghz;
+	bool cancel;
 };
 
 static inline void RTW89_SET_FWCMD_RA_IS_DIS(void *cmd, u32 val)