[PATCH v2 1/2] crypto: qcom-rng: fix support for ACPI-based systems

From: Brian Masney
Date: Tue Sep 03 2024 - 17:23:16 EST


The qcom-rng driver supports both ACPI and device tree based systems.
ACPI support was broken when the hw_random interface support was added.
Let's go ahead and fix this by adding a check for has_acpi_companion().

This fix was boot tested on a Qualcomm Amberwing server.

Fixes: f29cd5bb64c2 ("crypto: qcom-rng - Add hw_random interface support")
Reported-by: Ernesto A. Fernández <ernesto.mnd.fernandez@xxxxxxxxx>
Closes: https://lore.kernel.org/linux-arm-msm/20240828184019.GA21181@eaf/
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Brian Masney <bmasney@xxxxxxxxxx>
---
Note: I looked at updating the struct qcom_rng_acpi_match to have
driver_data point to &qcom_prng_ee_of_data, however that won't work
since struct acpi_device_id has a driver_data member of type
kernel_ulong_t. struct of_device_id has the data member set to
type const void *. As I get available time, I'll look to see if
it's possible to migrate struct acpi_device_id.driver_data from
a kernel_ulong_t to a const void * to match what's done in
struct of_device_id. That will allow removing the has_acpi_companion()
check in the future. I suspect that change is not going to be trivial
though.

drivers/crypto/qcom-rng.c | 35 +++++++++++++++++++----------------
1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/drivers/crypto/qcom-rng.c b/drivers/crypto/qcom-rng.c
index c670d7d0c11e..7ba978f0ce8b 100644
--- a/drivers/crypto/qcom-rng.c
+++ b/drivers/crypto/qcom-rng.c
@@ -176,6 +176,21 @@ static struct rng_alg qcom_rng_alg = {
}
};

+static struct qcom_rng_of_data qcom_prng_of_data = {
+ .skip_init = false,
+ .hwrng_support = false,
+};
+
+static struct qcom_rng_of_data qcom_prng_ee_of_data = {
+ .skip_init = true,
+ .hwrng_support = false,
+};
+
+static struct qcom_rng_of_data qcom_trng_of_data = {
+ .skip_init = true,
+ .hwrng_support = true,
+};
+
static int qcom_rng_probe(struct platform_device *pdev)
{
struct qcom_rng *rng;
@@ -196,7 +211,10 @@ static int qcom_rng_probe(struct platform_device *pdev)
if (IS_ERR(rng->clk))
return PTR_ERR(rng->clk);

- rng->of_data = (struct qcom_rng_of_data *)of_device_get_match_data(&pdev->dev);
+ if (has_acpi_companion(&pdev->dev))
+ rng->of_data = &qcom_prng_ee_of_data;
+ else
+ rng->of_data = (struct qcom_rng_of_data *)of_device_get_match_data(&pdev->dev);

qcom_rng_dev = rng;
ret = crypto_register_rng(&qcom_rng_alg);
@@ -231,21 +249,6 @@ static void qcom_rng_remove(struct platform_device *pdev)
qcom_rng_dev = NULL;
}

-static struct qcom_rng_of_data qcom_prng_of_data = {
- .skip_init = false,
- .hwrng_support = false,
-};
-
-static struct qcom_rng_of_data qcom_prng_ee_of_data = {
- .skip_init = true,
- .hwrng_support = false,
-};
-
-static struct qcom_rng_of_data qcom_trng_of_data = {
- .skip_init = true,
- .hwrng_support = true,
-};
-
static const struct acpi_device_id __maybe_unused qcom_rng_acpi_match[] = {
{ .id = "QCOM8160", .driver_data = 1 },
{}
--
2.46.0