[PATCH 4/8] wifi: brcmfmac: cfg80211: implement PMKID_V2 and fix delay busy-wait

[Shivesh <chanelshivesh@gmail.com>]

Implements PMKID_V2 for FILS fast-roaming support instead of falling
through to the V1 path. Additionally replaces a harmful mdelay() busy-wait
in brcmf_delay with usleep_range() to prevent CPU stalls.

Signed-off-by: Shivesh <shivesh@example.com>
---
 .../broadcom/brcm80211/brcmfmac/cfg80211.c    | 118 ++++++++++++++++--
 .../broadcom/brcm80211/brcmfmac/cfg80211.h    |   4 +-
 2 files changed, 110 insertions(+), 12 deletions(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index 0b55d445895f..7d7e5ececd22 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -3989,12 +3989,10 @@ static int brcmf_cfg80211_sched_scan_stop(struct wiphy *wiphy,
 
 static __always_inline void brcmf_delay(u32 ms)
 {
-	if (ms < 1000 / HZ) {
-		cond_resched();
-		mdelay(ms);
-	} else {
+	if (ms <= 20)
+		usleep_range(ms * 1000, ms * 1000 + 1000);
+	else
 		msleep(ms);
-	}
 }
 
 static s32 brcmf_config_wowl_pattern(struct brcmf_if *ifp, u8 cmd[4],
@@ -4364,6 +4362,104 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa,
 	return ret;
 }
 
+/**
+ * brcmf_pmksa_v2_op - update firmware PMKSA cache using the V2 list interface.
+ *
+ * V2 firmware (revision 12) uses a versioned flat list structure
+ * (brcmf_pmk_list_v2_le) rather than the per-entry operation model of V3.
+ * Each entry carries FILS-specific fields (raw PMK material, SSID, and
+ * fils_cache_id) in addition to the basic BSSID + PMKID pair, enabling
+ * FILS fast-roaming on devices that do not support V3.
+ *
+ * @cfg:   driver config structure holding the shadow V2 PMKSA list
+ * @ifp:   interface pointer
+ * @pmksa: the PMKSA to add/remove, or NULL for a flush
+ * @alive: true = add (set time_left to no-expiry), false = remove/flush
+ */
+static s32
+brcmf_pmksa_v2_op(struct brcmf_cfg80211_info *cfg, struct brcmf_if *ifp,
+		  struct cfg80211_pmksa *pmksa, bool alive)
+{
+	struct brcmf_pub *drvr = cfg->pub;
+	struct brcmf_pmk_list_v2_le *list = &cfg->pmk_list_v2;
+	struct brcmf_pmksa_v2 *pmk = list->pmk;
+	u32 npmk = le16_to_cpu(list->length);
+	u32 i;
+
+	/* npmk here stores the count of valid entries, repurposing the
+	 * length field of the shadow list as a counter.  We convert to
+	 * the wire format (byte length) when sending to firmware.
+	 */
+	if (!pmksa) {
+		/* Flush: zero the shadow list and push an empty V2 list. */
+		memset(list, 0, sizeof(*list));
+		goto send;
+	}
+
+	if (alive) {
+		/* Set: search for existing BSSID match first. */
+		for (i = 0; i < npmk; i++)
+			if (!memcmp(pmksa->bssid, pmk[i].bssid, ETH_ALEN))
+				break;
+
+		if (i >= BRCMF_MAXPMKID) {
+			bphy_err(drvr, "V2 PMKSA cache full (%d entries)\n",
+				 npmk);
+			return -EINVAL;
+		}
+
+		memset(&pmk[i], 0, sizeof(pmk[i]));
+		pmk[i].length = cpu_to_le16(sizeof(struct brcmf_pmksa_v2));
+		if (pmksa->bssid)
+			memcpy(pmk[i].bssid, pmksa->bssid, ETH_ALEN);
+		if (pmksa->pmkid)
+			memcpy(pmk[i].pmkid, pmksa->pmkid, WLAN_PMKID_LEN);
+		if (pmksa->pmk && pmksa->pmk_len &&
+		    pmksa->pmk_len <= WLAN_PMK_LEN_SUITE_B_192) {
+			memcpy(pmk[i].pmk, pmksa->pmk, pmksa->pmk_len);
+			pmk[i].pmk_len = cpu_to_le16(pmksa->pmk_len);
+		}
+		if (pmksa->ssid && pmksa->ssid_len) {
+			memcpy(pmk[i].ssid.SSID, pmksa->ssid, pmksa->ssid_len);
+			pmk[i].ssid.SSID_len = pmksa->ssid_len;
+		}
+		if (pmksa->fils_cache_id)
+			pmk[i].fils_cache_id = *pmksa->fils_cache_id;
+
+		if (i == npmk)
+			npmk++;
+	} else {
+		/* Delete: find by BSSID and compact the list. */
+		for (i = 0; i < npmk; i++)
+			if (!memcmp(pmksa->bssid, pmk[i].bssid, ETH_ALEN))
+				break;
+
+		if (i >= npmk) {
+			bphy_err(drvr, "V2 PMKSA entry not found\n");
+			return -EINVAL;
+		}
+
+		for (; i < npmk - 1; i++)
+			memcpy(&pmk[i], &pmk[i + 1], sizeof(pmk[i]));
+		memset(&pmk[npmk - 1], 0, sizeof(pmk[npmk - 1]));
+		npmk--;
+	}
+
+	/* Update shadow entry count (stored in length field). */
+	list->length = cpu_to_le16(npmk);
+
+send:
+	/* Build the wire-format header and send the full list to firmware.
+	 * version and length on the wire reflect the actual byte footprint.
+	 */
+	list->version = cpu_to_le16(BRCMF_PMKSA_VER_2);
+	list->length  = cpu_to_le16(offsetof(struct brcmf_pmk_list_v2_le, pmk) +
+				   npmk * sizeof(struct brcmf_pmksa_v2));
+
+	return brcmf_fil_iovar_data_set(ifp, "pmkid_info", list, sizeof(*list));
+}
+
+
 static __used s32
 brcmf_update_pmklist(struct brcmf_cfg80211_info *cfg, struct brcmf_if *ifp)
 {
@@ -4402,8 +4498,8 @@ brcmf_cfg80211_set_pmksa(struct wiphy *wiphy, struct net_device *ndev,
 
 	if (brcmf_feat_is_enabled(ifp, BRCMF_FEAT_PMKID_V3))
 		return brcmf_pmksa_v3_op(ifp, pmksa, true);
-
-	/* TODO: implement PMKID_V2 */
+	if (brcmf_feat_is_enabled(ifp, BRCMF_FEAT_PMKID_V2))
+		return brcmf_pmksa_v2_op(cfg, ifp, pmksa, true);
 
 	npmk = le32_to_cpu(cfg->pmk_list.npmk);
 	for (i = 0; i < npmk; i++)
@@ -4446,8 +4542,8 @@ brcmf_cfg80211_del_pmksa(struct wiphy *wiphy, struct net_device *ndev,
 
 	if (brcmf_feat_is_enabled(ifp, BRCMF_FEAT_PMKID_V3))
 		return brcmf_pmksa_v3_op(ifp, pmksa, false);
-
-	/* TODO: implement PMKID_V2 */
+	if (brcmf_feat_is_enabled(ifp, BRCMF_FEAT_PMKID_V2))
+		return brcmf_pmksa_v2_op(cfg, ifp, pmksa, false);
 
 	npmk = le32_to_cpu(cfg->pmk_list.npmk);
 	for (i = 0; i < npmk; i++)
@@ -4487,8 +4583,8 @@ brcmf_cfg80211_flush_pmksa(struct wiphy *wiphy, struct net_device *ndev)
 
 	if (brcmf_feat_is_enabled(ifp, BRCMF_FEAT_PMKID_V3))
 		return brcmf_pmksa_v3_op(ifp, NULL, false);
-
-	/* TODO: implement PMKID_V2 */
+	if (brcmf_feat_is_enabled(ifp, BRCMF_FEAT_PMKID_V2))
+		return brcmf_pmksa_v2_op(cfg, ifp, NULL, false);
 
 	memset(&cfg->pmk_list, 0, sizeof(cfg->pmk_list));
 	err = brcmf_update_pmklist(cfg, ifp);
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.h
index 6ceb30142905..57167fde5ba1 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.h
@@ -344,7 +344,8 @@ struct brcmf_cfg80211_wowl {
  * @bss_list: bss_list holding scanned ap information.
  * @bss_info: bss information for cfg80211 layer.
  * @conn_info: association info.
- * @pmk_list: wpa2 pmk list.
+ * @pmk_list: wpa2 pmk list (V1 firmware).
+ * @pmk_list_v2: wpa2 pmk list for V2 firmware (FILS-capable, firmware rev 12).
  * @scan_status: scan activity on the dongle.
  * @pub: common driver information.
  * @channel: current channel.
@@ -376,6 +377,7 @@ struct brcmf_cfg80211_info {
 	struct wl_cfg80211_bss_info *bss_info;
 	struct brcmf_cfg80211_connect_info conn_info;
 	struct brcmf_pmk_list_le pmk_list;
+	struct brcmf_pmk_list_v2_le pmk_list_v2;
 	unsigned long scan_status;
 	struct brcmf_pub *pub;
 	u32 channel;
-- 
2.53.0