libertas: add asynchronous firmware loading capability

As described at
http://article.gmane.org/gmane.linux.kernel.wireless.general/86084
libertas is taking a long time to load because it loads firmware
during module loading.

Add a new API for interface drivers to load their firmware
asynchronously. The same semantics of the firmware table are followed
like before.

Interface drivers will be converted in follow-up patches, then we can
remove the old, synchronous firmware loading function.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 164 insertions, 0 deletions

diff --git a/drivers/net/wireless/libertas/decl.h b/drivers/net/wireless/libertas/decl.h
index 2fb2e31733ee..84a3aa7ac570 100644
--- a/drivers/net/wireless/libertas/decl.h
+++ b/drivers/net/wireless/libertas/decl.h
@@ -19,6 +19,10 @@ struct lbs_fw_table {
 };
 
 struct lbs_private;
+typedef void (*lbs_fw_cb)(struct lbs_private *priv, int ret,
+                const struct firmware *helper, const struct firmware *mainfw);
+
+struct lbs_private;
 struct sk_buff;
 struct net_device;
 struct cmd_ds_command;
@@ -70,5 +74,9 @@ int lbs_get_firmware(struct device *dev, u32 card_model,
                         const struct lbs_fw_table *fw_table,
                         const struct firmware **helper,
                         const struct firmware **mainfw);
+int lbs_get_firmware_async(struct lbs_private *priv, struct device *device,
+                           u32 card_model, const struct lbs_fw_table *fw_table,
+                           lbs_fw_cb callback);
+void lbs_wait_for_firmware_load(struct lbs_private *priv);
 
 #endif
diff --git a/drivers/net/wireless/libertas/dev.h b/drivers/net/wireless/libertas/dev.h
index f3fd447131c2..672005430aca 100644
--- a/drivers/net/wireless/libertas/dev.h
+++ b/drivers/net/wireless/libertas/dev.h
@@ -7,6 +7,7 @@
 #define _LBS_DEV_H_
 
 #include "defs.h"
+#include "decl.h"
 #include "host.h"
 
 #include <linux/kfifo.h>
@@ -180,6 +181,15 @@ struct lbs_private {
         wait_queue_head_t scan_q;
         /* Whether the scan was initiated internally and not by cfg80211 */
         bool internal_scan;
+
+        /* Firmware load */
+        u32 fw_model;
+        wait_queue_head_t fw_waitq;
+        struct device *fw_device;
+        const struct firmware *helper_fw;
+        const struct lbs_fw_table *fw_table;
+        const struct lbs_fw_table *fw_iter;
+        lbs_fw_cb fw_callback;
 };
 
 extern struct cmd_confirm_sleep confirm_sleep;
diff --git a/drivers/net/wireless/libertas/firmware.c b/drivers/net/wireless/libertas/firmware.c
index 0c8c845b4901..cd23f1a8c98a 100644
--- a/drivers/net/wireless/libertas/firmware.c
+++ b/drivers/net/wireless/libertas/firmware.c
@@ -3,10 +3,151 @@
  */
 
 #include <linux/firmware.h>
+#include <linux/firmware.h>
 #include <linux/module.h>
 
+#include "dev.h"
 #include "decl.h"
 
+static void load_next_firmware_from_table(struct lbs_private *private);
+
+static void lbs_fw_loaded(struct lbs_private *priv, int ret,
+        const struct firmware *helper, const struct firmware *mainfw)
+{
+        unsigned long flags;
+
+        lbs_deb_fw("firmware load complete, code %d\n", ret);
+
+        /* User must free helper/mainfw */
+        priv->fw_callback(priv, ret, helper, mainfw);
+
+        spin_lock_irqsave(&priv->driver_lock, flags);
+        priv->fw_callback = NULL;
+        wake_up(&priv->fw_waitq);
+        spin_unlock_irqrestore(&priv->driver_lock, flags);
+}
+
+static void do_load_firmware(struct lbs_private *priv, const char *name,
+        void (*cb)(const struct firmware *fw, void *context))
+{
+        int ret;
+
+        lbs_deb_fw("Requesting %s\n", name);
+        ret = request_firmware_nowait(THIS_MODULE, true, name,
+                        priv->fw_device, GFP_KERNEL, priv, cb);
+        if (ret) {
+                lbs_deb_fw("request_firmware_nowait error %d\n", ret);
+                lbs_fw_loaded(priv, ret, NULL, NULL);
+        }
+}
+
+static void main_firmware_cb(const struct firmware *firmware, void *context)
+{
+        struct lbs_private *priv = context;
+
+        if (!firmware) {
+                /* Failed to find firmware: try next table entry */
+                load_next_firmware_from_table(priv);
+                return;
+        }
+
+        /* Firmware found! */
+        lbs_fw_loaded(priv, 0, priv->helper_fw, firmware);
+}
+
+static void helper_firmware_cb(const struct firmware *firmware, void *context)
+{
+        struct lbs_private *priv = context;
+
+        if (!firmware) {
+                /* Failed to find firmware: try next table entry */
+                load_next_firmware_from_table(priv);
+                return;
+        }
+
+        /* Firmware found! */
+        if (priv->fw_iter->fwname) {
+                priv->helper_fw = firmware;
+                do_load_firmware(priv, priv->fw_iter->fwname, main_firmware_cb);
+        } else {
+                /* No main firmware needed for this helper --> success! */
+                lbs_fw_loaded(priv, 0, firmware, NULL);
+        }
+}
+
+static void load_next_firmware_from_table(struct lbs_private *priv)
+{
+        const struct lbs_fw_table *iter;
+
+        if (!priv->fw_iter)
+                iter = priv->fw_table;
+        else
+                iter = ++priv->fw_iter;
+
+        if (priv->helper_fw) {
+                release_firmware(priv->helper_fw);
+                priv->helper_fw = NULL;
+        }
+
+next:
+        if (!iter->helper) {
+                /* End of table hit. */
+                lbs_fw_loaded(priv, -ENOENT, NULL, NULL);
+                return;
+        }
+
+        if (iter->model != priv->fw_model) {
+                iter++;
+                goto next;
+        }
+
+        priv->fw_iter = iter;
+        do_load_firmware(priv, iter->helper, helper_firmware_cb);
+}
+
+void lbs_wait_for_firmware_load(struct lbs_private *priv)
+{
+        wait_event(priv->fw_waitq, priv->fw_callback == NULL);
+}
+
+/**
+ *  lbs_get_firmware_async - Retrieves firmware asynchronously. Can load
+ *  either a helper firmware and a main firmware (2-stage), or just the helper.
+ *
+ *  @priv:      Pointer to lbs_private instance
+ *  @dev:       A pointer to &device structure
+ *  @card_model: Bus-specific card model ID used to filter firmware table
+ *              elements
+ *  @fw_table:  Table of firmware file names and device model numbers
+ *              terminated by an entry with a NULL helper name
+ *      @callback: User callback to invoke when firmware load succeeds or fails.
+ */
+int lbs_get_firmware_async(struct lbs_private *priv, struct device *device,
+                            u32 card_model, const struct lbs_fw_table *fw_table,
+                            lbs_fw_cb callback)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&priv->driver_lock, flags);
+        if (priv->fw_callback) {
+                lbs_deb_fw("firmware load already in progress\n");
+                spin_unlock_irqrestore(&priv->driver_lock, flags);
+                return -EBUSY;
+        }
+
+        priv->fw_device = device;
+        priv->fw_callback = callback;
+        priv->fw_table = fw_table;
+        priv->fw_iter = NULL;
+        priv->fw_model = card_model;
+        spin_unlock_irqrestore(&priv->driver_lock, flags);
+
+        lbs_deb_fw("Starting async firmware load\n");
+        load_next_firmware_from_table(priv);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(lbs_get_firmware_async);
+
 /**
  *  lbs_get_firmware - Retrieves two-stage firmware
  *
@@ -18,6 +159,8 @@
  *  @helper:    On success, the helper firmware; caller must free
  *  @mainfw:    On success, the main firmware; caller must free
  *
+ * Deprecated: use lbs_get_firmware_async() instead.
+ *
  *  returns:            0 on success, non-zero on failure
  */
 int lbs_get_firmware(struct device *dev, u32 card_model,
diff --git a/drivers/net/wireless/libertas/main.c b/drivers/net/wireless/libertas/main.c
index 7eaf992775ae..e96ee0aa8439 100644
--- a/drivers/net/wireless/libertas/main.c
+++ b/drivers/net/wireless/libertas/main.c
@@ -878,6 +878,7 @@ static int lbs_init_adapter(struct lbs_private *priv)
         priv->is_host_sleep_configured = 0;
         priv->is_host_sleep_activated = 0;
         init_waitqueue_head(&priv->host_sleep_q);
+        init_waitqueue_head(&priv->fw_waitq);
         mutex_init(&priv->lock);
 
         setup_timer(&priv->command_timer, lbs_cmd_timeout_handler,
@@ -1037,6 +1038,8 @@ void lbs_remove_card(struct lbs_private *priv)
         if (priv->wiphy_registered)
                 lbs_scan_deinit(priv);
 
+        lbs_wait_for_firmware_load(priv);
+
         /* worker thread destruction blocks on the in-flight command which
          * should have been cleared already in lbs_stop_card().
          */