brcmfmac: convert SDIO dpc implementation to workqueue

Switch SDIO dpc implementation from kernel thread to workqueue for
better performance and compatibility.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c b/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
index b0794e8..1d80e05 100644 (file)
--- a/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
@@ -495,7 +495,6 @@ struct brcmf_sdio {
 
        u32 hostintmask;        /* Copy of Host Interrupt Mask */
        u32 intstatus;  /* Intstatus bits (events) pending */
-       bool dpc_sched;         /* Indicates DPC schedule (intrpt rcvd) */
        bool fcstate;           /* State of dongle flow-control */
 
        uint blocksize;         /* Block size of SDIO transfers */
@@ -569,8 +568,8 @@ struct brcmf_sdio {
        bool wd_timer_valid;
        uint save_ms;
 
-       struct task_struct *dpc_tsk;
-       struct completion dpc_wait;
+       struct workqueue_struct *brcmf_wq;
+       struct work_struct datawork;
        struct list_head dpc_tsklst;
        spinlock_t dpc_tl_lock;
 
@@ -2183,12 +2182,6 @@ static void brcmf_sdbrcm_bus_stop(struct device *dev)
                bus->watchdog_tsk = NULL;
        }
 
-       if (bus->dpc_tsk && bus->dpc_tsk != current) {
-               send_sig(SIGTERM, bus->dpc_tsk, 1);
-               kthread_stop(bus->dpc_tsk);
-               bus->dpc_tsk = NULL;
-       }
-
        down(&bus->sdsem);
 
        /* Enable clock for device interrupts */
@@ -2261,15 +2254,31 @@ static inline void brcmf_sdbrcm_clrintr(struct brcmf_sdio *bus)
 }
 #endif         /* CONFIG_BRCMFMAC_SDIO_OOB */
 
-static bool brcmf_sdbrcm_dpc(struct brcmf_sdio *bus)
+static inline void brcmf_sdbrcm_adddpctsk(struct brcmf_sdio *bus)
+{
+       struct list_head *new_hd;
+       unsigned long flags;
+
+       if (in_interrupt())
+               new_hd = kzalloc(sizeof(struct list_head), GFP_ATOMIC);
+       else
+               new_hd = kzalloc(sizeof(struct list_head), GFP_KERNEL);
+       if (new_hd == NULL)
+               return;
+
+       spin_lock_irqsave(&bus->dpc_tl_lock, flags);
+       list_add_tail(new_hd, &bus->dpc_tsklst);
+       spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
+}
+
+static void brcmf_sdbrcm_dpc(struct brcmf_sdio *bus)
 {
        u32 intstatus, newstatus = 0;
        uint rxlimit = bus->rxbound;    /* Rx frames to read before resched */
        uint txlimit = bus->txbound;    /* Tx frames to send before resched */
        uint framecnt = 0;      /* Temporary counter of tx/rx frames */
        bool rxdone = true;     /* Flag for no more read data */
-       bool resched = false;   /* Flag indicating resched wanted */
-       int err;
+       int err = 0;
 
        brcmf_dbg(TRACE, "Enter\n");
 
@@ -2454,7 +2463,6 @@ clkwait:
                if (ret == 0)
                        bus->tx_seq = (bus->tx_seq + 1) % SDPCM_SEQUENCE_WRAP;
 
-               brcmf_dbg(INFO, "Return_dpc value is : %d\n", ret);
                bus->ctrl_frame_stat = false;
                brcmf_sdbrcm_wait_event_wakeup(bus);
        }
@@ -2477,15 +2485,13 @@ clkwait:
                bus->intstatus = 0;
        } else if (bus->clkstate == CLK_PENDING) {
                brcmf_dbg(INFO, "rescheduled due to CLK_PENDING awaiting I_CHIPACTIVE interrupt\n");
-               resched = true;
+               brcmf_sdbrcm_adddpctsk(bus);
        } else if (bus->intstatus || atomic_read(&bus->ipend) > 0 ||
                (!bus->fcstate && brcmu_pktq_mlen(&bus->txq, ~bus->flowcontrol)
                 && data_ok(bus)) || PKT_AVAILABLE()) {
-               resched = true;
+               brcmf_sdbrcm_adddpctsk(bus);
        }
 
-       bus->dpc_sched = resched;
-
        /* If we're done for now, turn off clock request. */
        if ((bus->clkstate != CLK_PENDING)
            && bus->idletime == BRCMF_IDLE_IMMEDIATE) {
@@ -2494,65 +2500,6 @@ clkwait:
        }
 
        up(&bus->sdsem);
-
-       return resched;
-}
-
-static inline void brcmf_sdbrcm_adddpctsk(struct brcmf_sdio *bus)
-{
-       struct list_head *new_hd;
-       unsigned long flags;
-
-       if (in_interrupt())
-               new_hd = kzalloc(sizeof(struct list_head), GFP_ATOMIC);
-       else
-               new_hd = kzalloc(sizeof(struct list_head), GFP_KERNEL);
-       if (new_hd == NULL)
-               return;
-
-       spin_lock_irqsave(&bus->dpc_tl_lock, flags);
-       list_add_tail(new_hd, &bus->dpc_tsklst);
-       spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
-}
-
-static int brcmf_sdbrcm_dpc_thread(void *data)
-{
-       struct brcmf_sdio *bus = (struct brcmf_sdio *) data;
-       struct list_head *cur_hd, *tmp_hd;
-       unsigned long flags;
-
-       allow_signal(SIGTERM);
-       /* Run until signal received */
-       while (1) {
-               if (kthread_should_stop())
-                       break;
-
-               if (list_empty(&bus->dpc_tsklst))
-                       if (wait_for_completion_interruptible(&bus->dpc_wait))
-                               break;
-
-               spin_lock_irqsave(&bus->dpc_tl_lock, flags);
-               list_for_each_safe(cur_hd, tmp_hd, &bus->dpc_tsklst) {
-                       spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
-
-                       if (bus->sdiodev->bus_if->state == BRCMF_BUS_DOWN) {
-                               /* after stopping the bus, exit thread */
-                               brcmf_sdbrcm_bus_stop(bus->sdiodev->dev);
-                               bus->dpc_tsk = NULL;
-                               spin_lock_irqsave(&bus->dpc_tl_lock, flags);
-                               break;
-                       }
-
-                       if (brcmf_sdbrcm_dpc(bus))
-                               brcmf_sdbrcm_adddpctsk(bus);
-
-                       spin_lock_irqsave(&bus->dpc_tl_lock, flags);
-                       list_del(cur_hd);
-                       kfree(cur_hd);
-               }
-               spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
-       }
-       return 0;
 }
 
 static int brcmf_sdbrcm_bus_txdata(struct device *dev, struct sk_buff *pkt)
@@ -2562,6 +2509,7 @@ static int brcmf_sdbrcm_bus_txdata(struct device *dev, struct sk_buff *pkt)
        struct brcmf_bus *bus_if = dev_get_drvdata(dev);
        struct brcmf_sdio_dev *sdiodev = bus_if->bus_priv.sdio;
        struct brcmf_sdio *bus = sdiodev->bus;
+       unsigned long flags;
 
        brcmf_dbg(TRACE, "Enter\n");
 
@@ -2600,13 +2548,15 @@ static int brcmf_sdbrcm_bus_txdata(struct device *dev, struct sk_buff *pkt)
        if (pktq_plen(&bus->txq, prec) > qcount[prec])
                qcount[prec] = pktq_plen(&bus->txq, prec);
 #endif
-       /* Schedule DPC if needed to send queued packet(s) */
-       if (!bus->dpc_sched) {
-               bus->dpc_sched = true;
-               if (bus->dpc_tsk) {
-                       brcmf_sdbrcm_adddpctsk(bus);
-                       complete(&bus->dpc_wait);
-               }
+
+       spin_lock_irqsave(&bus->dpc_tl_lock, flags);
+       if (list_empty(&bus->dpc_tsklst)) {
+               spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
+
+               brcmf_sdbrcm_adddpctsk(bus);
+               queue_work(bus->brcmf_wq, &bus->datawork);
+       } else {
+               spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
        }
 
        return ret;
@@ -2802,6 +2752,7 @@ brcmf_sdbrcm_bus_txctl(struct device *dev, unsigned char *msg, uint msglen)
        struct brcmf_bus *bus_if = dev_get_drvdata(dev);
        struct brcmf_sdio_dev *sdiodev = bus_if->bus_priv.sdio;
        struct brcmf_sdio *bus = sdiodev->bus;
+       unsigned long flags;
 
        brcmf_dbg(TRACE, "Enter\n");
 
@@ -2885,9 +2836,15 @@ brcmf_sdbrcm_bus_txctl(struct device *dev, unsigned char *msg, uint msglen)
                } while (ret < 0 && retries++ < TXRETRIES);
        }
 
-       if ((bus->idletime == BRCMF_IDLE_IMMEDIATE) && !bus->dpc_sched) {
+       spin_lock_irqsave(&bus->dpc_tl_lock, flags);
+       if ((bus->idletime == BRCMF_IDLE_IMMEDIATE) &&
+           list_empty(&bus->dpc_tsklst)) {
+               spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
+
                bus->activity = false;
                brcmf_sdbrcm_clkctl(bus, CLK_NONE, true);
+       } else {
+               spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
        }
 
        up(&bus->sdsem);
@@ -3698,11 +3655,8 @@ void brcmf_sdbrcm_isr(void *arg)
        if (!bus->intr)
                brcmf_dbg(ERROR, "isr w/o interrupt configured!\n");
 
-       bus->dpc_sched = true;
-       if (bus->dpc_tsk) {
-               brcmf_sdbrcm_adddpctsk(bus);
-               complete(&bus->dpc_wait);
-       }
+       brcmf_sdbrcm_adddpctsk(bus);
+       queue_work(bus->brcmf_wq, &bus->datawork);
 }
 
 static bool brcmf_sdbrcm_bus_watchdog(struct brcmf_sdio *bus)
@@ -3710,6 +3664,7 @@ static bool brcmf_sdbrcm_bus_watchdog(struct brcmf_sdio *bus)
 #ifdef DEBUG
        struct brcmf_bus *bus_if = dev_get_drvdata(bus->sdiodev->dev);
 #endif /* DEBUG */
+       unsigned long flags;
 
        brcmf_dbg(TIMER, "Enter\n");
 
@@ -3726,14 +3681,20 @@ static bool brcmf_sdbrcm_bus_watchdog(struct brcmf_sdio *bus)
                if (!bus->intr ||
                    (bus->sdcnt.intrcount == bus->sdcnt.lastintrs)) {
 
-                       if (!bus->dpc_sched) {
+                       spin_lock_irqsave(&bus->dpc_tl_lock, flags);
+                       if (list_empty(&bus->dpc_tsklst)) {
                                u8 devpend;
+                               spin_unlock_irqrestore(&bus->dpc_tl_lock,
+                                                      flags);
                                devpend = brcmf_sdio_regrb(bus->sdiodev,
                                                           SDIO_CCCR_INTx,
                                                           NULL);
                                intstatus =
                                    devpend & (INTR_STATUS_FUNC1 |
                                               INTR_STATUS_FUNC2);
+                       } else {
+                               spin_unlock_irqrestore(&bus->dpc_tl_lock,
+                                                      flags);
                        }
 
                        /* If there is something, make like the ISR and
@@ -3742,11 +3703,8 @@ static bool brcmf_sdbrcm_bus_watchdog(struct brcmf_sdio *bus)
                                bus->sdcnt.pollcnt++;
                                atomic_set(&bus->ipend, 1);
 
-                               bus->dpc_sched = true;
-                               if (bus->dpc_tsk) {
-                                       brcmf_sdbrcm_adddpctsk(bus);
-                                       complete(&bus->dpc_wait);
-                               }
+                               brcmf_sdbrcm_adddpctsk(bus);
+                               queue_work(bus->brcmf_wq, &bus->datawork);
                        }
                }
 
@@ -3800,6 +3758,26 @@ static bool brcmf_sdbrcm_chipmatch(u16 chipid)
        return false;
 }
 
+static void brcmf_sdio_dataworker(struct work_struct *work)
+{
+       struct brcmf_sdio *bus = container_of(work, struct brcmf_sdio,
+                                             datawork);
+       struct list_head *cur_hd, *tmp_hd;
+       unsigned long flags;
+
+       spin_lock_irqsave(&bus->dpc_tl_lock, flags);
+       list_for_each_safe(cur_hd, tmp_hd, &bus->dpc_tsklst) {
+               spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
+
+               brcmf_sdbrcm_dpc(bus);
+
+               spin_lock_irqsave(&bus->dpc_tl_lock, flags);
+               list_del(cur_hd);
+               kfree(cur_hd);
+       }
+       spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
+}
+
 static void brcmf_sdbrcm_release_malloc(struct brcmf_sdio *bus)
 {
        brcmf_dbg(TRACE, "Enter\n");
@@ -4012,6 +3990,9 @@ static void brcmf_sdbrcm_release(struct brcmf_sdio *bus)
                /* De-register interrupt handler */
                brcmf_sdio_intr_unregister(bus->sdiodev);
 
+               cancel_work_sync(&bus->datawork);
+               destroy_workqueue(bus->brcmf_wq);
+
                if (bus->sdiodev->bus_if->drvr) {
                        brcmf_detach(bus->sdiodev->dev);
                        brcmf_sdbrcm_release_dongle(bus);
@@ -4064,6 +4045,13 @@ void *brcmf_sdbrcm_probe(u32 regsva, struct brcmf_sdio_dev *sdiodev)
        init_waitqueue_head(&bus->ctrl_wait);
        init_waitqueue_head(&bus->dcmd_resp_wait);
 
+       bus->brcmf_wq = create_singlethread_workqueue("brcmf_wq");
+       if (bus->brcmf_wq == NULL) {
+               brcmf_dbg(ERROR, "insufficient memory to create txworkqueue\n");
+               goto fail;
+       }
+       INIT_WORK(&bus->datawork, brcmf_sdio_dataworker);
+
        /* Set up the watchdog timer */
        init_timer(&bus->timer);
        bus->timer.data = (unsigned long)bus;
@@ -4081,15 +4069,8 @@ void *brcmf_sdbrcm_probe(u32 regsva, struct brcmf_sdio_dev *sdiodev)
                bus->watchdog_tsk = NULL;
        }
        /* Initialize DPC thread */
-       init_completion(&bus->dpc_wait);
        INIT_LIST_HEAD(&bus->dpc_tsklst);
        spin_lock_init(&bus->dpc_tl_lock);
-       bus->dpc_tsk = kthread_run(brcmf_sdbrcm_dpc_thread,
-                                  bus, "brcmf_dpc");
-       if (IS_ERR(bus->dpc_tsk)) {
-               pr_warn("brcmf_dpc thread failed to start\n");
-               bus->dpc_tsk = NULL;
-       }
 
        /* Assign bus interface call back */
        bus->sdiodev->bus_if->brcmf_bus_stop = brcmf_sdbrcm_bus_stop;