6 files changed, 58 insertions, 32 deletions

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 95a031e9eced..f6e3e5abc117 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -100,12 +100,12 @@ config HW_RANDOM_BCM2835
 	  If unsure, say Y.
 
 config HW_RANDOM_IPROC_RNG200
-	tristate "Broadcom iProc RNG200 support"
-	depends on ARCH_BCM_IPROC
+	tristate "Broadcom iProc/STB RNG200 support"
+	depends on ARCH_BCM_IPROC || ARCH_BRCMSTB
 	default HW_RANDOM
 	---help---
 	  This driver provides kernel-side support for the RNG200
-	  hardware found on the Broadcom iProc SoCs.
+	  hardware found on the Broadcom iProc and STB SoCs.
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called iproc-rng200
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 9701ac7d8b47..657b8770b6b9 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -292,26 +292,48 @@ static struct miscdevice rng_miscdev = {
 	.groups		= rng_dev_groups,
 };
 
+static int enable_best_rng(void)
+{
+	int ret = -ENODEV;
+
+	BUG_ON(!mutex_is_locked(&rng_mutex));
+
+	/* rng_list is sorted by quality, use the best (=first) one */
+	if (!list_empty(&rng_list)) {
+		struct hwrng *new_rng;
+
+		new_rng = list_entry(rng_list.next, struct hwrng, list);
+		ret = ((new_rng == current_rng) ? 0 : set_current_rng(new_rng));
+		if (!ret)
+			cur_rng_set_by_user = 0;
+	}
+
+	return ret;
+}
+
 static ssize_t hwrng_attr_current_store(struct device *dev,
 					struct device_attribute *attr,
 					const char *buf, size_t len)
 {
-	int err;
+	int err = -ENODEV;
 	struct hwrng *rng;
 
 	err = mutex_lock_interruptible(&rng_mutex);
 	if (err)
 		return -ERESTARTSYS;
-	err = -ENODEV;
-	list_for_each_entry(rng, &rng_list, list) {
-		if (sysfs_streq(rng->name, buf)) {
-			err = 0;
-			cur_rng_set_by_user = 1;
-			if (rng != current_rng)
+
+	if (sysfs_streq(buf, "")) {
+		err = enable_best_rng();
+	} else {
+		list_for_each_entry(rng, &rng_list, list) {
+			if (sysfs_streq(rng->name, buf)) {
+				cur_rng_set_by_user = 1;
 				err = set_current_rng(rng);
-			break;
+				break;
+			}
 		}
 	}
+
 	mutex_unlock(&rng_mutex);
 
 	return err ? : len;
@@ -423,7 +445,7 @@ static void start_khwrngd(void)
 {
 	hwrng_fill = kthread_run(hwrng_fillfn, NULL, "hwrng");
 	if (IS_ERR(hwrng_fill)) {
-		pr_err("hwrng_fill thread creation failed");
+		pr_err("hwrng_fill thread creation failed\n");
 		hwrng_fill = NULL;
 	}
 }
@@ -493,17 +515,8 @@ void hwrng_unregister(struct hwrng *rng)
 	mutex_lock(&rng_mutex);
 
 	list_del(&rng->list);
-	if (current_rng == rng) {
-		drop_current_rng();
-		cur_rng_set_by_user = 0;
-		/* rng_list is sorted by quality, use the best (=first) one */
-		if (!list_empty(&rng_list)) {
-			struct hwrng *new_rng;
-
-			new_rng = list_entry(rng_list.next, struct hwrng, list);
-			set_current_rng(new_rng);
-		}
-	}
+	if (current_rng == rng)
+		enable_best_rng();
 
 	if (list_empty(&rng_list)) {
 		mutex_unlock(&rng_mutex);
diff --git a/drivers/char/hw_random/iproc-rng200.c b/drivers/char/hw_random/iproc-rng200.c
index 3eaf7cb96d36..8b5a20b35293 100644
--- a/drivers/char/hw_random/iproc-rng200.c
+++ b/drivers/char/hw_random/iproc-rng200.c
@@ -220,6 +220,7 @@ static int iproc_rng200_probe(struct platform_device *pdev)
 }
 
 static const struct of_device_id iproc_rng200_of_match[] = {
+	{ .compatible = "brcm,bcm7278-rng200", },
 	{ .compatible = "brcm,iproc-rng200", },
 	{},
 };
diff --git a/drivers/char/hw_random/pseries-rng.c b/drivers/char/hw_random/pseries-rng.c
index d9f46b437cc2..4e2a3f635277 100644
--- a/drivers/char/hw_random/pseries-rng.c
+++ b/drivers/char/hw_random/pseries-rng.c
@@ -72,7 +72,7 @@ static int pseries_rng_remove(struct vio_dev *dev)
 	return 0;
 }
 
-static struct vio_device_id pseries_rng_driver_ids[] = {
+static const struct vio_device_id pseries_rng_driver_ids[] = {
 	{ "ibm,random-v1", "ibm,random"},
 	{ "", "" }
 };
diff --git a/drivers/char/hw_random/timeriomem-rng.c b/drivers/char/hw_random/timeriomem-rng.c
index 03ff5483d865..f615684028af 100644
--- a/drivers/char/hw_random/timeriomem-rng.c
+++ b/drivers/char/hw_random/timeriomem-rng.c
@@ -53,13 +53,6 @@ static int timeriomem_rng_read(struct hwrng *hwrng, void *data,
 	int period_us = ktime_to_us(priv->period);
 
 	/*
-	 * The RNG provides 32-bits per read.  Ensure there is enough space for
-	 * at minimum one read.
-	 */
-	if (max < sizeof(u32))
-		return 0;
-
-	/*
 	 * There may not have been enough time for new data to be generated
 	 * since the last request.  If the caller doesn't want to wait, let them
 	 * bail out.  Otherwise, wait for the completion.  If the new data has
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index 3fa2f8a009b3..b89df66ea1ae 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -184,7 +184,26 @@ static int virtrng_freeze(struct virtio_device *vdev)
 
 static int virtrng_restore(struct virtio_device *vdev)
 {
-	return probe_common(vdev);
+	int err;
+
+	err = probe_common(vdev);
+	if (!err) {
+		struct virtrng_info *vi = vdev->priv;
+
+		/*
+		 * Set hwrng_removed to ensure that virtio_read()
+		 * does not block waiting for data before the
+		 * registration is complete.
+		 */
+		vi->hwrng_removed = true;
+		err = hwrng_register(&vi->hwrng);
+		if (!err) {
+			vi->hwrng_register_done = true;
+			vi->hwrng_removed = false;
+		}
+	}
+
+	return err;
 }
 #endif