[PATCH v12 02/15] crypto: ti - Fix spinlock inconsistency in DTHEv2

[T Pratham <t-pratham@ti.com>]

Probe and remove functions use spin_(un)lock for acquiring the
dthe_dev_list.lock. But dthe_get_dev uses the bh variant. Change
spin_(un)lock to spin_(un)lock_bh to avoid potential deadlock when a
softIRQ process tries to acquire the already held lock.

While we're here, also change the order in probe to add device to the
global list after all the fields in the dev_data are initialized. So
that a concurrent TFM allocation does not occur and try to fetch
uninitialized fields.

Fixes: 52f641bc63a46 ("crypto: ti - Add driver for DTHE V2 AES Engine (ECB, CBC)")
Signed-off-by: T Pratham <t-pratham@ti.com>
---
 drivers/crypto/ti/dthev2-common.c | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/crypto/ti/dthev2-common.c b/drivers/crypto/ti/dthev2-common.c
index cb4b8b38a5ec8..a7d3831f2f9cb 100644
--- a/drivers/crypto/ti/dthev2-common.c
+++ b/drivers/crypto/ti/dthev2-common.c
@@ -152,15 +152,9 @@ static int dthe_probe(struct platform_device *pdev)
 	if (IS_ERR(dev_data->regs))
 		return PTR_ERR(dev_data->regs);
 
-	platform_set_drvdata(pdev, dev_data);
-
-	spin_lock(&dthe_dev_list.lock);
-	list_add(&dev_data->list, &dthe_dev_list.dev_list);
-	spin_unlock(&dthe_dev_list.lock);
-
 	ret = dthe_dma_init(dev_data);
 	if (ret)
-		goto probe_dma_err;
+		return ret;
 
 	dev_data->engine = crypto_engine_alloc_init(dev, 1);
 	if (!dev_data->engine) {
@@ -174,24 +168,29 @@ static int dthe_probe(struct platform_device *pdev)
 		goto probe_engine_start_err;
 	}
 
+	spin_lock_bh(&dthe_dev_list.lock);
+	platform_set_drvdata(pdev, dev_data);
+	list_add(&dev_data->list, &dthe_dev_list.dev_list);
+	spin_unlock_bh(&dthe_dev_list.lock);
+
 	ret = dthe_register_algs();
 	if (ret) {
 		dev_err(dev, "Failed to register algs\n");
-		goto probe_engine_start_err;
+		goto probe_register_algs_err;
 	}
 
 	return 0;
 
+probe_register_algs_err:
+	spin_lock_bh(&dthe_dev_list.lock);
+	list_del(&dev_data->list);
+	spin_unlock_bh(&dthe_dev_list.lock);
 probe_engine_start_err:
 	crypto_engine_exit(dev_data->engine);
 probe_engine_err:
 	dma_release_channel(dev_data->dma_aes_rx);
 	dma_release_channel(dev_data->dma_aes_tx);
 	dma_release_channel(dev_data->dma_sha_tx);
-probe_dma_err:
-	spin_lock(&dthe_dev_list.lock);
-	list_del(&dev_data->list);
-	spin_unlock(&dthe_dev_list.lock);
 
 	return ret;
 }
@@ -200,9 +199,9 @@ static void dthe_remove(struct platform_device *pdev)
 {
 	struct dthe_data *dev_data = platform_get_drvdata(pdev);
 
-	spin_lock(&dthe_dev_list.lock);
+	spin_lock_bh(&dthe_dev_list.lock);
 	list_del(&dev_data->list);
-	spin_unlock(&dthe_dev_list.lock);
+	spin_unlock_bh(&dthe_dev_list.lock);
 
 	dthe_unregister_algs();
 
-- 
2.34.1