wl12xx: AP-mode - management of links in PS-mode

Update the PS mode of each link according to a bitmap polled from
fw_status. Manually notify mac80211 about PS mode changes in connected
stations.

mac80211 will only be notified about PS start when the station is in PS
and there is a small number of TX blocks from this link ready in HW.
This is required for waking up the remote station since the TIM is
updated entirely by FW.

When a station enters mac80211-PS-mode, we drop all the skbs in the
low-level TX queues belonging to this sta with STAT_TX_FILTERED
to keep our queues clean.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>

5 files changed, 186 insertions, 12 deletions

diff --git a/drivers/net/wireless/wl12xx/main.c b/drivers/net/wireless/wl12xx/main.c
index 5772a33d79ec..95aa19ae84e5 100644
--- a/drivers/net/wireless/wl12xx/main.c
+++ b/drivers/net/wireless/wl12xx/main.c
@@ -537,6 +537,57 @@ static int wl1271_plt_init(struct wl1271 *wl)
         return ret;
 }
 
+static void wl1271_irq_ps_regulate_link(struct wl1271 *wl, u8 hlid, u8 tx_blks)
+{
+        bool fw_ps;
+
+        /* only regulate station links */
+        if (hlid < WL1271_AP_STA_HLID_START)
+                return;
+
+        fw_ps = test_bit(hlid, (unsigned long *)&wl->ap_fw_ps_map);
+
+        /*
+         * Wake up from high level PS if the STA is asleep with too little
+         * blocks in FW or if the STA is awake.
+         */
+        if (!fw_ps || tx_blks < WL1271_PS_STA_MAX_BLOCKS)
+                wl1271_ps_link_end(wl, hlid);
+
+        /* Start high-level PS if the STA is asleep with enough blocks in FW */
+        else if (fw_ps && tx_blks >= WL1271_PS_STA_MAX_BLOCKS)
+                wl1271_ps_link_start(wl, hlid, true);
+}
+
+static void wl1271_irq_update_links_status(struct wl1271 *wl,
+                                       struct wl1271_fw_ap_status *status)
+{
+        u32 cur_fw_ps_map;
+        u8 hlid;
+
+        cur_fw_ps_map = le32_to_cpu(status->link_ps_bitmap);
+        if (wl->ap_fw_ps_map != cur_fw_ps_map) {
+                wl1271_debug(DEBUG_PSM,
+                             "link ps prev 0x%x cur 0x%x changed 0x%x",
+                             wl->ap_fw_ps_map, cur_fw_ps_map,
+                             wl->ap_fw_ps_map ^ cur_fw_ps_map);
+
+                wl->ap_fw_ps_map = cur_fw_ps_map;
+        }
+
+        for (hlid = WL1271_AP_STA_HLID_START; hlid < AP_MAX_LINKS; hlid++) {
+                u8 cnt = status->tx_lnk_free_blks[hlid] -
+                        wl->links[hlid].prev_freed_blks;
+
+                wl->links[hlid].prev_freed_blks =
+                        status->tx_lnk_free_blks[hlid];
+                wl->links[hlid].allocated_blks -= cnt;
+
+                wl1271_irq_ps_regulate_link(wl, hlid,
+                                            wl->links[hlid].allocated_blks);
+        }
+}
+
 static void wl1271_fw_status(struct wl1271 *wl,
                              struct wl1271_fw_full_status *full_status)
 {
@@ -574,16 +625,9 @@ static void wl1271_fw_status(struct wl1271 *wl,
         if (total)
                 clear_bit(WL1271_FLAG_FW_TX_BUSY, &wl->flags);
 
-        if (wl->bss_type == BSS_TYPE_AP_BSS) {
-                for (i = 0; i < AP_MAX_LINKS; i++) {
-                        u8 cnt = status->tx_lnk_free_blks[i] -
-                                wl->links[i].prev_freed_blks;
-
-                        wl->links[i].prev_freed_blks =
-                                status->tx_lnk_free_blks[i];
-                        wl->links[i].allocated_blks -= cnt;
-                }
-        }
+        /* for AP update num of allocated TX blocks per link and ps status */
+        if (wl->bss_type == BSS_TYPE_AP_BSS)
+                wl1271_irq_update_links_status(wl, &full_status->ap);
 
         /* update the host-chipset time offset */
         getnstimeofday(&ts);
@@ -1241,6 +1285,8 @@ static void __wl1271_op_remove_interface(struct wl1271 *wl)
         wl->filters = 0;
         wl1271_free_ap_keys(wl);
         memset(wl->ap_hlid_map, 0, sizeof(wl->ap_hlid_map));
+        wl->ap_fw_ps_map = 0;
+        wl->ap_ps_map = 0;
 
         for (i = 0; i < NUM_TX_QUEUES; i++)
                 wl->tx_blocks_freed[i] = 0;
@@ -2649,10 +2695,10 @@ static int wl1271_allocate_sta(struct wl1271 *wl,
         }
 
         wl_sta = (struct wl1271_station *)sta->drv_priv;
-
         __set_bit(id, wl->ap_hlid_map);
         wl_sta->hlid = WL1271_AP_STA_HLID_START + id;
         *hlid = wl_sta->hlid;
+        memcpy(wl->links[wl_sta->hlid].addr, sta->addr, ETH_ALEN);
         return 0;
 }
 
@@ -2664,7 +2710,10 @@ static void wl1271_free_sta(struct wl1271 *wl, u8 hlid)
                 return;
 
         __clear_bit(id, wl->ap_hlid_map);
+        memset(wl->links[hlid].addr, 0, ETH_ALEN);
         wl1271_tx_reset_link_queues(wl, hlid);
+        __clear_bit(hlid, &wl->ap_ps_map);
+        __clear_bit(hlid, (unsigned long *)&wl->ap_fw_ps_map);
 }
 
 static int wl1271_op_sta_add(struct ieee80211_hw *hw,
@@ -3355,6 +3404,8 @@ struct ieee80211_hw *wl1271_alloc_hw(void)
         wl->set_bss_type = MAX_BSS_TYPE;
         wl->fw_bss_type = MAX_BSS_TYPE;
         wl->last_tx_hlid = 0;
+        wl->ap_ps_map = 0;
+        wl->ap_fw_ps_map = 0;
 
         memset(wl->tx_frames_map, 0, sizeof(wl->tx_frames_map));
         for (i = 0; i < ACX_TX_DESCRIPTORS; i++)
diff --git a/drivers/net/wireless/wl12xx/ps.c b/drivers/net/wireless/wl12xx/ps.c
index b7b3139e00fb..5c347b1bd17f 100644
--- a/drivers/net/wireless/wl12xx/ps.c
+++ b/drivers/net/wireless/wl12xx/ps.c
@@ -24,6 +24,7 @@
 #include "reg.h"
 #include "ps.h"
 #include "io.h"
+#include "tx.h"
 
 #define WL1271_WAKEUP_TIMEOUT 500
 
@@ -172,3 +173,82 @@ int wl1271_ps_set_mode(struct wl1271 *wl, enum wl1271_cmd_ps_mode mode,
 
         return ret;
 }
+
+static void wl1271_ps_filter_frames(struct wl1271 *wl, u8 hlid)
+{
+        int i, filtered = 0;
+        struct sk_buff *skb;
+        struct ieee80211_tx_info *info;
+        unsigned long flags;
+
+        /* filter all frames currently the low level queus for this hlid */
+        for (i = 0; i < NUM_TX_QUEUES; i++) {
+                while ((skb = skb_dequeue(&wl->links[hlid].tx_queue[i]))) {
+                        info = IEEE80211_SKB_CB(skb);
+                        info->flags |= IEEE80211_TX_STAT_TX_FILTERED;
+                        info->status.rates[0].idx = -1;
+                        ieee80211_tx_status(wl->hw, skb);
+                        filtered++;
+                }
+        }
+
+        spin_lock_irqsave(&wl->wl_lock, flags);
+        wl->tx_queue_count -= filtered;
+        spin_unlock_irqrestore(&wl->wl_lock, flags);
+
+        wl1271_handle_tx_low_watermark(wl);
+}
+
+void wl1271_ps_link_start(struct wl1271 *wl, u8 hlid, bool clean_queues)
+{
+        struct ieee80211_sta *sta;
+
+        if (test_bit(hlid, &wl->ap_ps_map))
+                return;
+
+        wl1271_debug(DEBUG_PSM, "start mac80211 PSM on hlid %d blks %d "
+                     "clean_queues %d", hlid, wl->links[hlid].allocated_blks,
+                     clean_queues);
+
+        rcu_read_lock();
+        sta = ieee80211_find_sta(wl->vif, wl->links[hlid].addr);
+        if (!sta) {
+                wl1271_error("could not find sta %pM for starting ps",
+                             wl->links[hlid].addr);
+                rcu_read_unlock();
+                return;
+        }
+
+        ieee80211_sta_ps_transition_ni(sta, true);
+        rcu_read_unlock();
+
+        /* do we want to filter all frames from this link's queues? */
+        if (clean_queues)
+                wl1271_ps_filter_frames(wl, hlid);
+
+        __set_bit(hlid, &wl->ap_ps_map);
+}
+
+void wl1271_ps_link_end(struct wl1271 *wl, u8 hlid)
+{
+        struct ieee80211_sta *sta;
+
+        if (!test_bit(hlid, &wl->ap_ps_map))
+                return;
+
+        wl1271_debug(DEBUG_PSM, "end mac80211 PSM on hlid %d", hlid);
+
+        __clear_bit(hlid, &wl->ap_ps_map);
+
+        rcu_read_lock();
+        sta = ieee80211_find_sta(wl->vif, wl->links[hlid].addr);
+        if (!sta) {
+                wl1271_error("could not find sta %pM for ending ps",
+                             wl->links[hlid].addr);
+                goto end;
+        }
+
+        ieee80211_sta_ps_transition_ni(sta, false);
+end:
+        rcu_read_unlock();
+}
diff --git a/drivers/net/wireless/wl12xx/ps.h b/drivers/net/wireless/wl12xx/ps.h
index 8415060f08e5..fc1f4c193593 100644
--- a/drivers/net/wireless/wl12xx/ps.h
+++ b/drivers/net/wireless/wl12xx/ps.h
@@ -32,5 +32,7 @@ int wl1271_ps_set_mode(struct wl1271 *wl, enum wl1271_cmd_ps_mode mode,
 void wl1271_ps_elp_sleep(struct wl1271 *wl);
 int wl1271_ps_elp_wakeup(struct wl1271 *wl, bool chip_awake);
 void wl1271_elp_work(struct work_struct *work);
+void wl1271_ps_link_start(struct wl1271 *wl, u8 hlid, bool clean_queues);
+void wl1271_ps_link_end(struct wl1271 *wl, u8 hlid);
 
 #endif /* __WL1271_PS_H__ */
diff --git a/drivers/net/wireless/wl12xx/tx.c b/drivers/net/wireless/wl12xx/tx.c
index ea1382bd38f4..ac60d577319f 100644
--- a/drivers/net/wireless/wl12xx/tx.c
+++ b/drivers/net/wireless/wl12xx/tx.c
@@ -86,6 +86,26 @@ static void wl1271_tx_ap_update_inconnection_sta(struct wl1271 *wl,
                 wl1271_acx_set_inconnection_sta(wl, hdr->addr1);
 }
 
+static void wl1271_tx_regulate_link(struct wl1271 *wl, u8 hlid)
+{
+        bool fw_ps;
+        u8 tx_blks;
+
+        /* only regulate station links */
+        if (hlid < WL1271_AP_STA_HLID_START)
+                return;
+
+        fw_ps = test_bit(hlid, (unsigned long *)&wl->ap_fw_ps_map);
+        tx_blks = wl->links[hlid].allocated_blks;
+
+        /*
+         * if in FW PS and there is enough data in FW we can put the link
+         * into high-level PS and clean out its TX queues.
+         */
+        if (fw_ps && tx_blks >= WL1271_PS_STA_MAX_BLOCKS)
+                wl1271_ps_link_start(wl, hlid, true);
+}
+
 u8 wl1271_tx_get_hlid(struct sk_buff *skb)
 {
         struct ieee80211_tx_info *control = IEEE80211_SKB_CB(skb);
@@ -277,8 +297,10 @@ static int wl1271_prepare_tx_frame(struct wl1271 *wl, struct sk_buff *skb,
         if (ret < 0)
                 return ret;
 
-        if (wl->bss_type == BSS_TYPE_AP_BSS)
+        if (wl->bss_type == BSS_TYPE_AP_BSS) {
                 wl1271_tx_ap_update_inconnection_sta(wl, skb);
+                wl1271_tx_regulate_link(wl, hlid);
+        }
 
         wl1271_tx_fill_hdr(wl, skb, extra, info, hlid);
 
diff --git a/drivers/net/wireless/wl12xx/wl12xx.h b/drivers/net/wireless/wl12xx/wl12xx.h
index 0e00c5be99d3..338acc9f60b3 100644
--- a/drivers/net/wireless/wl12xx/wl12xx.h
+++ b/drivers/net/wireless/wl12xx/wl12xx.h
@@ -153,6 +153,17 @@ extern u32 wl12xx_debug_level;
 #define WL1271_AP_BROADCAST_HLID   1
 #define WL1271_AP_STA_HLID_START   2
 
+/*
+ * When in AP-mode, we allow (at least) this number of mem-blocks
+ * to be transmitted to FW for a STA in PS-mode. Only when packets are
+ * present in the FW buffers it will wake the sleeping STA. We want to put
+ * enough packets for the driver to transmit all of its buffered data before
+ * the STA goes to sleep again. But we don't want to take too much mem-blocks
+ * as it might hurt the throughput of active STAs.
+ * The number of blocks (18) is enough for 2 large packets.
+ */
+#define WL1271_PS_STA_MAX_BLOCKS  (2 * 9)
+
 #define WL1271_AP_BSS_INDEX        0
 #define WL1271_AP_DEF_INACTIV_SEC  300
 #define WL1271_AP_DEF_BEACON_EXP   20
@@ -326,6 +337,8 @@ struct wl1271_link {
         /* accounting for allocated / available TX blocks in FW */
         u8 allocated_blks;
         u8 prev_freed_blks;
+
+        u8 addr[ETH_ALEN];
 };
 
 struct wl1271 {
@@ -516,6 +529,12 @@ struct wl1271 {
 
         /* the hlid of the link where the last transmitted skb came from */
         int last_tx_hlid;
+
+        /* AP-mode - a bitmap of links currently in PS mode according to FW */
+        u32 ap_fw_ps_map;
+
+        /* AP-mode - a bitmap of links currently in PS mode in mac80211 */
+        unsigned long ap_ps_map;
 };
 
 struct wl1271_station {