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 <hs4233@mail.mn-solutions.de>
Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 10 insertions, 55 deletions

diff --git a/drivers/net/wireless/libertas/if_sdio.c b/drivers/net/wireless/libertas/if_sdio.c
index eed73204bcc9..51f664bbee9d 100644
--- a/drivers/net/wireless/libertas/if_sdio.c
+++ b/drivers/net/wireless/libertas/if_sdio.c
@@ -91,8 +91,6 @@ struct if_sdio_card {
         const char              *firmware;
 
         u8                      buffer[65536];
-        u8                      int_cause;
-        u32                     event;
 
         spinlock_t              lock;
         struct if_sdio_packet   *packets;
@@ -129,13 +127,13 @@ static u16 if_sdio_read_scratch(struct if_sdio_card *card, int *err)
 static int if_sdio_handle_cmd(struct if_sdio_card *card,
                 u8 *buffer, unsigned size)
 {
+        struct lbs_private *priv = card->priv;
         int ret;
         unsigned long flags;
+        u8 i;
 
         lbs_deb_enter(LBS_DEB_SDIO);
 
-        spin_lock_irqsave(&card->priv->driver_lock, flags);
-
         if (size > LBS_CMD_BUFFER_SIZE) {
                 lbs_deb_sdio("response packet too large (%d bytes)\n",
                         (int)size);
@@ -143,20 +141,20 @@ static int if_sdio_handle_cmd(struct if_sdio_card *card,
                 goto out;
         }
 
-        memcpy(card->priv->upld_buf, buffer, size);
-        card->priv->upld_len = size;
+        spin_lock_irqsave(&priv->driver_lock, flags);
 
-        card->int_cause |= MRVDRV_CMD_UPLD_RDY;
+        i = (priv->resp_idx == 0) ? 1 : 0;
+        BUG_ON(priv->resp_len[i]);
+        priv->resp_len[i] = size;
+        memcpy(priv->resp_buf[i], buffer, size);
+        lbs_notify_command_response(priv, i);
 
-        lbs_interrupt(card->priv);
+        spin_unlock_irqrestore(&card->priv->driver_lock, flags);
 
         ret = 0;
 
 out:
-        spin_unlock_irqrestore(&card->priv->driver_lock, flags);
-
         lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);
-
         return ret;
 }
 
@@ -202,7 +200,6 @@ static int if_sdio_handle_event(struct if_sdio_card *card,
                 u8 *buffer, unsigned size)
 {
         int ret;
-        unsigned long flags;
         u32 event;
 
         lbs_deb_enter(LBS_DEB_SDIO);
@@ -222,18 +219,9 @@ static int if_sdio_handle_event(struct if_sdio_card *card,
                 event |= buffer[2] << 16;
                 event |= buffer[1] << 8;
                 event |= buffer[0] << 0;
-                event <<= SBI_EVENT_CAUSE_SHIFT;
         }
 
-        spin_lock_irqsave(&card->priv->driver_lock, flags);
-
-        card->event = event;
-        card->int_cause |= MRVDRV_CARDEVENT;
-
-        lbs_interrupt(card->priv);
-
-        spin_unlock_irqrestore(&card->priv->driver_lock, flags);
-
+        lbs_queue_event(card->priv, event & 0xFF);
         ret = 0;
 
 out:
@@ -770,37 +758,6 @@ out:
         return ret;
 }
 
-static int if_sdio_get_int_status(struct lbs_private *priv, u8 *ireg)
-{
-        struct if_sdio_card *card;
-
-        lbs_deb_enter(LBS_DEB_SDIO);
-
-        card = priv->card;
-
-        *ireg = card->int_cause;
-        card->int_cause = 0;
-
-        lbs_deb_leave(LBS_DEB_SDIO);
-
-        return 0;
-}
-
-static int if_sdio_read_event_cause(struct lbs_private *priv)
-{
-        struct if_sdio_card *card;
-
-        lbs_deb_enter(LBS_DEB_SDIO);
-
-        card = priv->card;
-
-        priv->eventcause = card->event;
-
-        lbs_deb_leave(LBS_DEB_SDIO);
-
-        return 0;
-}
-
 /*******************************************************************/
 /* SDIO callbacks                                                  */
 /*******************************************************************/
@@ -953,8 +910,6 @@ static int if_sdio_probe(struct sdio_func *func,
 
         priv->card = card;
         priv->hw_host_to_card = if_sdio_host_to_card;
-        priv->hw_get_int_status = if_sdio_get_int_status;
-        priv->hw_read_event_cause = if_sdio_read_event_cause;
 
         priv->fw_ready = 1;