[PATCH] talitos: allocate channels with main struct

[Rosen Penev <rosenp@gmail.com>]

Use a flexible array member to combine allocations.

Add __counted_by for extra runtime analysis.

Error in case of no channels as they are required.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 v2: error when no channels
 drivers/crypto/talitos.c | 19 +++++++------------
 drivers/crypto/talitos.h |  5 +++--
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index bc61d0fe3514..bd4cc06ee13c 100644
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -3409,14 +3409,20 @@ static int talitos_probe(struct platform_device *ofdev)
 	struct device *dev = &ofdev->dev;
 	struct device_node *np = ofdev->dev.of_node;
 	struct talitos_private *priv;
+	unsigned int num_channels;
 	int i, err;
 	int stride;
 	struct resource *res;
 
-	priv = devm_kzalloc(dev, sizeof(struct talitos_private), GFP_KERNEL);
+	if (of_property_read_u32(np, "fsl,num-channels", &num_channels))
+		return -EINVAL;
+
+	priv = devm_kzalloc(dev, struct_size(priv, chan, num_channels), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
 
+	priv->num_channels = num_channels;
+
 	INIT_LIST_HEAD(&priv->alg_list);
 
 	dev_set_drvdata(dev, priv);
@@ -3436,7 +3442,6 @@ static int talitos_probe(struct platform_device *ofdev)
 	}
 
 	/* get SEC version capabilities from device tree */
-	of_property_read_u32(np, "fsl,num-channels", &priv->num_channels);
 	of_property_read_u32(np, "fsl,channel-fifo-len", &priv->chfifo_len);
 	of_property_read_u32(np, "fsl,exec-units-mask", &priv->exec_units);
 	of_property_read_u32(np, "fsl,descriptor-types-mask",
@@ -3511,16 +3516,6 @@ static int talitos_probe(struct platform_device *ofdev)
 		}
 	}
 
-	priv->chan = devm_kcalloc(dev,
-				  priv->num_channels,
-				  sizeof(struct talitos_channel),
-				  GFP_KERNEL);
-	if (!priv->chan) {
-		dev_err(dev, "failed to allocate channel management space\n");
-		err = -ENOMEM;
-		goto err_out;
-	}
-
 	priv->fifo_len = roundup_pow_of_two(priv->chfifo_len);
 
 	for (i = 0; i < priv->num_channels; i++) {
diff --git a/drivers/crypto/talitos.h b/drivers/crypto/talitos.h
index 1a93ee355929..34b0b5fab7e7 100644
--- a/drivers/crypto/talitos.h
+++ b/drivers/crypto/talitos.h
@@ -139,8 +139,6 @@ struct talitos_private {
 	 */
 	unsigned int fifo_len;
 
-	struct talitos_channel *chan;
-
 	/* next channel to be assigned next incoming descriptor */
 	atomic_t last_chan ____cacheline_aligned;
 
@@ -153,6 +151,9 @@ struct talitos_private {
 	/* hwrng device */
 	struct hwrng rng;
 	bool rng_registered;
+
+	struct talitos_channel chan[] __counted_by(num_channels);
+
 };
 
 /* .features flag */
-- 
2.54.0