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Date: Wed, 4 Nov 2009 13:39:56 -0800
From: Inaky Perez-Gonzalez <inaky@...ux.intel.com>
To: netdev@...r.kernel.org, wimax@...uxwimax.org
Subject: [PATCH 2.6.33/3 05/13] wimax/i2400m: cache firmware on system suspend
In preparation for a reset_resume implementation, have the firmware
image be cached in memory when the system goes to suspend and released
when out.
This is needed in case the device resets during suspend; the driver
can't load firmware until resume is completed or bad deadlocks
happen.
The modus operandi for this was copied from the Orinoco USB driver.
The caching is done with a kobject to avoid race conditions when
releasing it. The fw loader path is altered only to first check for a
cached image before trying to load from disk. A Power Management event
notifier is register to call i2400m_fw_cache() or i2400m_fw_uncache()
which take care of the actual cache management.
Signed-off-by: Inaky Perez-Gonzalez <inaky@...ux.intel.com>
---
drivers/net/wimax/i2400m/driver.c | 51 ++++++++++++
drivers/net/wimax/i2400m/fw.c | 159 ++++++++++++++++++++++++++++++++++---
drivers/net/wimax/i2400m/i2400m.h | 16 ++++
3 files changed, 213 insertions(+), 13 deletions(-)
diff --git a/drivers/net/wimax/i2400m/driver.c b/drivers/net/wimax/i2400m/driver.c
index f07d852..07d12be 100644
--- a/drivers/net/wimax/i2400m/driver.c
+++ b/drivers/net/wimax/i2400m/driver.c
@@ -66,6 +66,7 @@
#include <linux/wimax/i2400m.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/suspend.h>
#define D_SUBMODULE driver
#include "debug-levels.h"
@@ -555,6 +556,51 @@ void i2400m_dev_stop(struct i2400m *i2400m)
/*
+ * Listen to PM events to cache the firmware before suspend/hibernation
+ *
+ * When the device comes out of suspend, it might go into reset and
+ * firmware has to be uploaded again. At resume, most of the times, we
+ * can't load firmware images from disk, so we need to cache it.
+ *
+ * i2400m_fw_cache() will allocate a kobject and attach the firmware
+ * to it; that way we don't have to worry too much about the fw loader
+ * hitting a race condition.
+ *
+ * Note: modus operandi stolen from the Orinoco driver; thx.
+ */
+static
+int i2400m_pm_notifier(struct notifier_block *notifier,
+ unsigned long pm_event,
+ void *unused)
+{
+ struct i2400m *i2400m =
+ container_of(notifier, struct i2400m, pm_notifier);
+ struct device *dev = i2400m_dev(i2400m);
+
+ d_fnstart(3, dev, "(i2400m %p pm_event %lx)\n", i2400m, pm_event);
+ switch (pm_event) {
+ case PM_HIBERNATION_PREPARE:
+ case PM_SUSPEND_PREPARE:
+ i2400m_fw_cache(i2400m);
+ break;
+ case PM_POST_RESTORE:
+ /* Restore from hibernation failed. We need to clean
+ * up in exactly the same way, so fall through. */
+ case PM_POST_HIBERNATION:
+ case PM_POST_SUSPEND:
+ i2400m_fw_uncache(i2400m);
+ break;
+
+ case PM_RESTORE_PREPARE:
+ default:
+ break;
+ }
+ d_fnend(3, dev, "(i2400m %p pm_event %lx) = void\n", i2400m, pm_event);
+ return NOTIFY_DONE;
+}
+
+
+/*
* The device has rebooted; fix up the device and the driver
*
* Tear down the driver communication with the device, reload the
@@ -738,6 +784,9 @@ int i2400m_setup(struct i2400m *i2400m, enum i2400m_bri bm_flags)
goto error_read_mac_addr;
random_ether_addr(i2400m->src_mac_addr);
+ i2400m->pm_notifier.notifier_call = i2400m_pm_notifier;
+ register_pm_notifier(&i2400m->pm_notifier);
+
result = register_netdev(net_dev); /* Okey dokey, bring it up */
if (result < 0) {
dev_err(dev, "cannot register i2400m network device: %d\n",
@@ -783,6 +832,7 @@ error_wimax_dev_add:
error_dev_start:
unregister_netdev(net_dev);
error_register_netdev:
+ unregister_pm_notifier(&i2400m->pm_notifier);
error_read_mac_addr:
error_bootrom_init:
d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
@@ -809,6 +859,7 @@ void i2400m_release(struct i2400m *i2400m)
wimax_dev_rm(&i2400m->wimax_dev);
i2400m_dev_stop(i2400m);
unregister_netdev(i2400m->wimax_dev.net_dev);
+ unregister_pm_notifier(&i2400m->pm_notifier);
kfree(i2400m->bm_ack_buf);
kfree(i2400m->bm_cmd_buf);
d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
diff --git a/drivers/net/wimax/i2400m/fw.c b/drivers/net/wimax/i2400m/fw.c
index 5719f4a..69f9e45 100644
--- a/drivers/net/wimax/i2400m/fw.c
+++ b/drivers/net/wimax/i2400m/fw.c
@@ -105,6 +105,13 @@
* read an acknolwedgement from it (or an asynchronous notification)
* from it.
*
+ * FIRMWARE LOADING
+ *
+ * Note that in some cases, we can't just load a firmware file (for
+ * example, when resuming). For that, we might cache the firmware
+ * file. Thus, when doing the bootstrap, if there is a cache firmware
+ * file, it is used; if not, loading from disk is attempted.
+ *
* ROADMAP
*
* i2400m_barker_db_init Called by i2400m_driver_init()
@@ -114,9 +121,10 @@
*
* i2400m_dev_bootstrap Called by __i2400m_dev_start()
* request_firmware
- * i2400m_fw_check
- * i2400m_fw_hdr_check
- * i2400m_fw_dnload
+ * i2400m_fw_bootstrap
+ * i2400m_fw_check
+ * i2400m_fw_hdr_check
+ * i2400m_fw_dnload
* release_firmware
*
* i2400m_fw_dnload
@@ -141,6 +149,10 @@
*
* i2400m_bm_cmd_prepare Used by bus-drivers to prep
* commands before sending
+ *
+ * i2400m_pm_notifier Called on Power Management events
+ * i2400m_fw_cache
+ * i2400m_fw_uncache
*/
#include <linux/firmware.h>
#include <linux/sched.h>
@@ -1459,6 +1471,61 @@ error_dev_rebooted:
goto hw_reboot;
}
+static
+int i2400m_fw_bootstrap(struct i2400m *i2400m, const struct firmware *fw,
+ enum i2400m_bri flags)
+{
+ int ret;
+ struct device *dev = i2400m_dev(i2400m);
+ const struct i2400m_bcf_hdr *bcf; /* Firmware data */
+
+ d_fnstart(5, dev, "(i2400m %p)\n", i2400m);
+ bcf = (void *) fw->data;
+ ret = i2400m_fw_check(i2400m, bcf, fw->size);
+ if (ret >= 0)
+ ret = i2400m_fw_dnload(i2400m, bcf, fw->size, flags);
+ if (ret < 0)
+ dev_err(dev, "%s: cannot use: %d, skipping\n",
+ i2400m->fw_name, ret);
+ kfree(i2400m->fw_hdrs);
+ i2400m->fw_hdrs = NULL;
+ d_fnend(5, dev, "(i2400m %p) = %d\n", i2400m, ret);
+ return ret;
+}
+
+
+/* Refcounted container for firmware data */
+struct i2400m_fw {
+ struct kref kref;
+ const struct firmware *fw;
+};
+
+
+static
+void i2400m_fw_destroy(struct kref *kref)
+{
+ struct i2400m_fw *i2400m_fw =
+ container_of(kref, struct i2400m_fw, kref);
+ release_firmware(i2400m_fw->fw);
+ kfree(i2400m_fw);
+}
+
+
+static
+struct i2400m_fw *i2400m_fw_get(struct i2400m_fw *i2400m_fw)
+{
+ if (i2400m_fw != NULL && i2400m_fw != (void *) ~0)
+ kref_get(&i2400m_fw->kref);
+ return i2400m_fw;
+}
+
+
+static
+void i2400m_fw_put(struct i2400m_fw *i2400m_fw)
+{
+ kref_put(&i2400m_fw->kref, i2400m_fw_destroy);
+}
+
/**
* i2400m_dev_bootstrap - Bring the device to a known state and upload firmware
@@ -1479,12 +1546,28 @@ int i2400m_dev_bootstrap(struct i2400m *i2400m, enum i2400m_bri flags)
{
int ret, itr;
struct device *dev = i2400m_dev(i2400m);
- const struct firmware *fw;
+ struct i2400m_fw *i2400m_fw;
const struct i2400m_bcf_hdr *bcf; /* Firmware data */
+ const struct firmware *fw;
const char *fw_name;
d_fnstart(5, dev, "(i2400m %p)\n", i2400m);
+ ret = -ENODEV;
+ spin_lock(&i2400m->rx_lock);
+ i2400m_fw = i2400m_fw_get(i2400m->fw_cached);
+ spin_unlock(&i2400m->rx_lock);
+ if (i2400m_fw == (void *) ~0) {
+ dev_err(dev, "can't load firmware now!");
+ goto out;
+ } else if (i2400m_fw != NULL) {
+ dev_info(dev, "firmware %s: loading from cache\n",
+ i2400m->fw_name);
+ ret = i2400m_fw_bootstrap(i2400m, i2400m_fw->fw, flags);
+ i2400m_fw_put(i2400m_fw);
+ goto out;
+ }
+
/* Load firmware files to memory. */
for (itr = 0, bcf = NULL, ret = -ENOENT; ; itr++) {
fw_name = i2400m->bus_fw_names[itr];
@@ -1500,21 +1583,71 @@ int i2400m_dev_bootstrap(struct i2400m *i2400m, enum i2400m_bri flags)
fw_name, ret);
continue;
}
- bcf = (void *) fw->data;
i2400m->fw_name = fw_name;
- ret = i2400m_fw_check(i2400m, bcf, fw->size);
- if (ret >= 0)
- ret = i2400m_fw_dnload(i2400m, bcf, fw->size, flags);
- if (ret < 0)
- dev_err(dev, "%s: cannot use: %d, skipping\n",
- fw_name, ret);
- kfree(i2400m->fw_hdrs);
- i2400m->fw_hdrs = NULL;
+ ret = i2400m_fw_bootstrap(i2400m, fw, flags);
release_firmware(fw);
if (ret >= 0) /* firmware loaded succesfully */
break;
+ i2400m->fw_name = NULL;
}
+out:
d_fnend(5, dev, "(i2400m %p) = %d\n", i2400m, ret);
return ret;
}
EXPORT_SYMBOL_GPL(i2400m_dev_bootstrap);
+
+
+void i2400m_fw_cache(struct i2400m *i2400m)
+{
+ int result;
+ struct i2400m_fw *i2400m_fw;
+ struct device *dev = i2400m_dev(i2400m);
+
+ /* if there is anything there, free it -- now, this'd be weird */
+ spin_lock(&i2400m->rx_lock);
+ i2400m_fw = i2400m->fw_cached;
+ spin_unlock(&i2400m->rx_lock);
+ if (i2400m_fw != NULL && i2400m_fw != (void *) ~0) {
+ i2400m_fw_put(i2400m_fw);
+ WARN(1, "%s:%u: still cached fw still present?\n",
+ __func__, __LINE__);
+ }
+
+ if (i2400m->fw_name == NULL) {
+ dev_err(dev, "firmware n/a: can't cache\n");
+ i2400m_fw = (void *) ~0;
+ goto out;
+ }
+
+ i2400m_fw = kzalloc(sizeof(*i2400m_fw), GFP_ATOMIC);
+ if (i2400m_fw == NULL)
+ goto out;
+ kref_init(&i2400m_fw->kref);
+ result = request_firmware(&i2400m_fw->fw, i2400m->fw_name, dev);
+ if (result < 0) {
+ dev_err(dev, "firmware %s: failed to cache: %d\n",
+ i2400m->fw_name, result);
+ kfree(i2400m_fw);
+ i2400m_fw = (void *) ~0;
+ } else
+ dev_info(dev, "firmware %s: cached\n", i2400m->fw_name);
+out:
+ spin_lock(&i2400m->rx_lock);
+ i2400m->fw_cached = i2400m_fw;
+ spin_unlock(&i2400m->rx_lock);
+}
+
+
+void i2400m_fw_uncache(struct i2400m *i2400m)
+{
+ struct i2400m_fw *i2400m_fw;
+
+ spin_lock(&i2400m->rx_lock);
+ i2400m_fw = i2400m->fw_cached;
+ i2400m->fw_cached = NULL;
+ spin_unlock(&i2400m->rx_lock);
+
+ if (i2400m_fw != NULL && i2400m_fw != (void *) ~0)
+ i2400m_fw_put(i2400m_fw);
+}
+
diff --git a/drivers/net/wimax/i2400m/i2400m.h b/drivers/net/wimax/i2400m/i2400m.h
index 0c165de..916b1d3 100644
--- a/drivers/net/wimax/i2400m/i2400m.h
+++ b/drivers/net/wimax/i2400m/i2400m.h
@@ -424,11 +424,21 @@ struct i2400m_barker_db;
* @fw_hdrs: NULL terminated array of pointers to the firmware
* headers. This is only available during firmware load time.
*
+ * @fw_cached: Used to cache firmware when the system goes to
+ * suspend/standby/hibernation (as on resume we can't read it). If
+ * NULL, no firmware was cached, read it. If ~0, you can't read
+ * any firmware files (the system still didn't come out of suspend
+ * and failed to cache one), so abort; otherwise, a valid cached
+ * firmware to be used. Access to this variable is protected by
+ * the spinlock i2400m->rx_lock.
+ *
* @barker: barker type that the device uses; this is initialized by
* i2400m_is_boot_barker() the first time it is called. Then it
* won't change during the life cycle of the device and everytime
* a boot barker is received, it is just verified for it being the
* same.
+ *
+ * @pm_notifier: used to register for PM events
*/
struct i2400m {
struct wimax_dev wimax_dev; /* FIRST! See doc */
@@ -495,7 +505,10 @@ struct i2400m {
const char *fw_name; /* name of the current firmware image */
unsigned long fw_version; /* version of the firmware interface */
const struct i2400m_bcf_hdr **fw_hdrs;
+ struct i2400m_fw *fw_cached; /* protected by rx_lock */
struct i2400m_barker_db *barker;
+
+ struct notifier_block pm_notifier;
};
@@ -671,6 +684,9 @@ extern void i2400m_tx_release(struct i2400m *);
extern int i2400m_rx_setup(struct i2400m *);
extern void i2400m_rx_release(struct i2400m *);
+extern void i2400m_fw_cache(struct i2400m *);
+extern void i2400m_fw_uncache(struct i2400m *);
+
extern void i2400m_net_rx(struct i2400m *, struct sk_buff *, unsigned,
const void *, int);
extern void i2400m_net_erx(struct i2400m *, struct sk_buff *,
--
1.6.2.5
--
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