From 7919b89c8276d657976d4d4d6b7cb58ea1aa08c3 Mon Sep 17 00:00:00 2001 From: Holger Schurig Date: Tue, 1 Apr 2008 14:50:43 +0200 Subject: libertas: convert libertas driver to use an event/cmdresp queue This patch (co-developed by Dan Williams and Holger Schurig) uses a kfifo object for events and a swapping buffer scheme for the command response to preserve the zero-copy semantics of the CF driver and keep memory usage low. The main thread should only ever touch the buffer indexed by priv->resp_idx, while the interface code is free to write to the second buffer, then swap priv->resp_idx under the driver spinlock. The firmware specs only permit one in-flight command, so there will only ever be one command response to process at a time. Signed-off-by: Holger Schurig Signed-off-by: Dan Williams Signed-off-by: John W. Linville --- drivers/net/wireless/libertas/main.c | 158 +++++++++++++++++++---------------- 1 file changed, 88 insertions(+), 70 deletions(-) (limited to 'drivers/net/wireless/libertas/main.c') diff --git a/drivers/net/wireless/libertas/main.c b/drivers/net/wireless/libertas/main.c index 8f112261097..406f54d4095 100644 --- a/drivers/net/wireless/libertas/main.c +++ b/drivers/net/wireless/libertas/main.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include @@ -480,10 +481,9 @@ static void lbs_tx_timeout(struct net_device *dev) dev->trans_start = jiffies; - if (priv->currenttxskb) { - priv->eventcause = 0x01000000; - lbs_send_tx_feedback(priv); - } + if (priv->currenttxskb) + lbs_send_tx_feedback(priv, 0); + /* XX: Shouldn't we also call into the hw-specific driver to kick it somehow? */ lbs_host_to_card_done(priv); @@ -659,7 +659,6 @@ static int lbs_thread(void *data) struct net_device *dev = data; struct lbs_private *priv = dev->priv; wait_queue_t wait; - u8 ireg = 0; lbs_deb_enter(LBS_DEB_THREAD); @@ -667,9 +666,10 @@ static int lbs_thread(void *data) for (;;) { int shouldsleep; + u8 resp_idx; - lbs_deb_thread( "main-thread 111: intcounter=%d currenttxskb=%p dnld_sent=%d\n", - priv->intcounter, priv->currenttxskb, priv->dnld_sent); + lbs_deb_thread("1: currenttxskb %p, dnld_sent %d\n", + priv->currenttxskb, priv->dnld_sent); add_wait_queue(&priv->waitq, &wait); set_current_state(TASK_INTERRUPTIBLE); @@ -681,8 +681,6 @@ static int lbs_thread(void *data) shouldsleep = 1; /* We need to wait until we're _told_ to die */ else if (priv->psstate == PS_STATE_SLEEP) shouldsleep = 1; /* Sleep mode. Nothing we can do till it wakes */ - else if (priv->intcounter) - shouldsleep = 0; /* Interrupt pending. Deal with it now */ else if (priv->cmd_timed_out) shouldsleep = 0; /* Command timed out. Recover */ else if (!priv->fw_ready) @@ -695,29 +693,34 @@ static int lbs_thread(void *data) shouldsleep = 1; /* Can't send a command; one already running */ else if (!list_empty(&priv->cmdpendingq)) shouldsleep = 0; /* We have a command to send */ + else if (__kfifo_len(priv->event_fifo)) + shouldsleep = 0; /* We have an event to process */ + else if (priv->resp_len[priv->resp_idx]) + shouldsleep = 0; /* We have a command response */ else shouldsleep = 1; /* No command */ if (shouldsleep) { - lbs_deb_thread("main-thread sleeping... Conn=%d IntC=%d PS_mode=%d PS_State=%d\n", - priv->connect_status, priv->intcounter, - priv->psmode, priv->psstate); + lbs_deb_thread("sleeping, connect_status %d, " + "ps_mode %d, ps_state %d\n", + priv->connect_status, + priv->psmode, priv->psstate); spin_unlock_irq(&priv->driver_lock); schedule(); } else spin_unlock_irq(&priv->driver_lock); - lbs_deb_thread("main-thread 222 (waking up): intcounter=%d currenttxskb=%p dnld_sent=%d\n", - priv->intcounter, priv->currenttxskb, priv->dnld_sent); + lbs_deb_thread("2: currenttxskb %p, dnld_send %d\n", + priv->currenttxskb, priv->dnld_sent); set_current_state(TASK_RUNNING); remove_wait_queue(&priv->waitq, &wait); - lbs_deb_thread("main-thread 333: intcounter=%d currenttxskb=%p dnld_sent=%d\n", - priv->intcounter, priv->currenttxskb, priv->dnld_sent); + lbs_deb_thread("3: currenttxskb %p, dnld_sent %d\n", + priv->currenttxskb, priv->dnld_sent); if (kthread_should_stop()) { - lbs_deb_thread("main-thread: break from main thread\n"); + lbs_deb_thread("break from main thread\n"); break; } @@ -726,35 +729,23 @@ static int lbs_thread(void *data) continue; } - spin_lock_irq(&priv->driver_lock); - - if (priv->intcounter) { - u8 int_status; + lbs_deb_thread("4: currenttxskb %p, dnld_sent %d\n", + priv->currenttxskb, priv->dnld_sent); - priv->intcounter = 0; - int_status = priv->hw_get_int_status(priv, &ireg); - - if (int_status) { - lbs_deb_thread("main-thread: reading HOST_INT_STATUS_REG failed\n"); - spin_unlock_irq(&priv->driver_lock); - continue; - } - priv->hisregcpy |= ireg; - } - - lbs_deb_thread("main-thread 444: intcounter=%d currenttxskb=%p dnld_sent=%d\n", - priv->intcounter, priv->currenttxskb, priv->dnld_sent); - - /* command response? */ - if (priv->hisregcpy & MRVDRV_CMD_UPLD_RDY) { - lbs_deb_thread("main-thread: cmd response ready\n"); - - priv->hisregcpy &= ~MRVDRV_CMD_UPLD_RDY; + spin_lock_irq(&priv->driver_lock); + /* Process any pending command response */ + resp_idx = priv->resp_idx; + if (priv->resp_len[resp_idx]) { spin_unlock_irq(&priv->driver_lock); - lbs_process_rx_command(priv); + lbs_process_command_response(priv, + priv->resp_buf[resp_idx], + priv->resp_len[resp_idx]); spin_lock_irq(&priv->driver_lock); + priv->resp_len[resp_idx] = 0; } + spin_unlock_irq(&priv->driver_lock); + /* command timeout stuff */ if (priv->cmd_timed_out && priv->cur_cmd) { struct cmd_ctrl_node *cmdnode = priv->cur_cmd; @@ -775,21 +766,18 @@ static int lbs_thread(void *data) } priv->cmd_timed_out = 0; - /* Any Card Event */ - if (priv->hisregcpy & MRVDRV_CARDEVENT) { - lbs_deb_thread("main-thread: Card Event Activity\n"); - - priv->hisregcpy &= ~MRVDRV_CARDEVENT; + /* Process hardware events, e.g. card removed, link lost */ + spin_lock_irq(&priv->driver_lock); + while (__kfifo_len(priv->event_fifo)) { + u32 event; - if (priv->hw_read_event_cause(priv)) { - lbs_pr_alert("main-thread: hw_read_event_cause failed\n"); - spin_unlock_irq(&priv->driver_lock); - continue; - } - spin_unlock_irq(&priv->driver_lock); - lbs_process_event(priv); - } else + __kfifo_get(priv->event_fifo, (unsigned char *) &event, + sizeof(event)); spin_unlock_irq(&priv->driver_lock); + lbs_process_event(priv, event); + spin_lock_irq(&priv->driver_lock); + } + spin_unlock_irq(&priv->driver_lock); if (!priv->fw_ready) continue; @@ -798,8 +786,10 @@ static int lbs_thread(void *data) if (priv->psstate == PS_STATE_PRE_SLEEP && !priv->dnld_sent && !priv->cur_cmd) { if (priv->connect_status == LBS_CONNECTED) { - lbs_deb_thread("main_thread: PRE_SLEEP--intcounter=%d currenttxskb=%p dnld_sent=%d cur_cmd=%p, confirm now\n", - priv->intcounter, priv->currenttxskb, priv->dnld_sent, priv->cur_cmd); + lbs_deb_thread("pre-sleep, currenttxskb %p, " + "dnld_sent %d, cur_cmd %p\n", + priv->currenttxskb, priv->dnld_sent, + priv->cur_cmd); lbs_ps_confirm_sleep(priv); } else { @@ -809,7 +799,8 @@ static int lbs_thread(void *data) * after firmware fixes it */ priv->psstate = PS_STATE_AWAKE; - lbs_pr_alert("main-thread: ignore PS_SleepConfirm in non-connected state\n"); + lbs_pr_alert("ignore PS_SleepConfirm in " + "non-connected state\n"); } } @@ -1046,7 +1037,18 @@ static int lbs_init_adapter(struct lbs_private *priv) /* Allocate the command buffers */ if (lbs_allocate_cmd_buffer(priv)) { lbs_pr_err("Out of memory allocating command buffers\n"); - ret = -1; + ret = -ENOMEM; + goto out; + } + priv->resp_idx = 0; + priv->resp_len[0] = priv->resp_len[1] = 0; + + /* Create the event FIFO */ + priv->event_fifo = kfifo_alloc(sizeof(u32) * 16, GFP_KERNEL, NULL); + if (IS_ERR(priv->event_fifo)) { + lbs_pr_err("Out of memory allocating event FIFO buffer\n"); + ret = -ENOMEM; + goto out; } out: @@ -1060,6 +1062,8 @@ static void lbs_free_adapter(struct lbs_private *priv) lbs_deb_enter(LBS_DEB_MAIN); lbs_free_cmd_buffer(priv); + if (priv->event_fifo) + kfifo_free(priv->event_fifo); del_timer(&priv->command_timer); kfree(priv->networks); priv->networks = NULL; @@ -1434,27 +1438,41 @@ out: return ret; } -/** - * @brief This function handles the interrupt. it will change PS - * state if applicable. it will wake up main_thread to handle - * the interrupt event as well. - * - * @param dev A pointer to net_device structure - * @return n/a - */ -void lbs_interrupt(struct lbs_private *priv) +void lbs_queue_event(struct lbs_private *priv, u32 event) +{ + unsigned long flags; + + lbs_deb_enter(LBS_DEB_THREAD); + spin_lock_irqsave(&priv->driver_lock, flags); + + if (priv->psstate == PS_STATE_SLEEP) + priv->psstate = PS_STATE_AWAKE; + + __kfifo_put(priv->event_fifo, (unsigned char *) &event, sizeof(u32)); + + wake_up_interruptible(&priv->waitq); + + spin_unlock_irqrestore(&priv->driver_lock, flags); + lbs_deb_leave(LBS_DEB_THREAD); +} +EXPORT_SYMBOL_GPL(lbs_queue_event); + +void lbs_notify_command_response(struct lbs_private *priv, u8 resp_idx) { lbs_deb_enter(LBS_DEB_THREAD); - lbs_deb_thread("lbs_interrupt: intcounter=%d\n", priv->intcounter); - priv->intcounter++; if (priv->psstate == PS_STATE_SLEEP) priv->psstate = PS_STATE_AWAKE; + + /* Swap buffers by flipping the response index */ + BUG_ON(resp_idx > 1); + priv->resp_idx = resp_idx; + wake_up_interruptible(&priv->waitq); lbs_deb_leave(LBS_DEB_THREAD); } -EXPORT_SYMBOL_GPL(lbs_interrupt); +EXPORT_SYMBOL_GPL(lbs_notify_command_response); static int __init lbs_init_module(void) { -- cgit v1.2.3-70-g09d2