This change adds devm_hwrng_register and devm_hwrng_unregister which
use can simplify error unwinding and unbinding code paths in device
drivers.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/char/hw_random/core.c | 42 ++++++++++++++++++++++++++++++++++++++++++
include/linux/hw_random.h | 4 ++++
2 files changed, 46 insertions(+)
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 32a8a86..83161dd 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -536,6 +536,48 @@ void hwrng_unregister(struct hwrng *rng)
}
EXPORT_SYMBOL_GPL(hwrng_unregister);
+static void devm_hwrng_release(struct device *dev, void *res)
+{
+ hwrng_unregister(*(struct hwrng **)res);
+}
+
+static int devm_hwrng_match(struct device *dev, void *res, void *data)
+{
+ struct hwrng **r = res;
+
+ if (WARN_ON(!r || !*r))
+ return 0;
+
+ return *r == data;
+}
+
+int devm_hwrng_register(struct device *dev, struct hwrng *rng)
+{
+ struct hwrng **ptr;
+ int error;
+
+ ptr = devres_alloc(devm_hwrng_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+
+ error = hwrng_register(rng);
+ if (error) {
+ devres_free(ptr);
+ return error;
+ }
+
+ *ptr = rng;
+ devres_add(dev, ptr);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(devm_hwrng_register);
+
+void devm_hwrng_unregister(struct device *dev, struct hwrng *rng)
+{
+ devres_release(dev, devm_hwrng_release, devm_hwrng_match, rng);
+}
+EXPORT_SYMBOL_GPL(devm_hwrng_unregister);
+
static int __init hwrng_modinit(void)
{
return register_miscdev();
diff --git a/include/linux/hw_random.h b/include/linux/hw_random.h
index eb7b414..4f7d8f4 100644
--- a/include/linux/hw_random.h
+++ b/include/linux/hw_random.h
@@ -50,10 +50,14 @@ struct hwrng {
struct completion cleanup_done;
};
+struct device;
+
/** Register a new Hardware Random Number Generator driver. */
extern int hwrng_register(struct hwrng *rng);
+extern int devm_hwrng_register(struct device *dev, struct hwrng *rng);
/** Unregister a Hardware Random Number Generator driver. */
extern void hwrng_unregister(struct hwrng *rng);
+extern void devm_hwrng_unregister(struct device *dve, struct hwrng *rng);
/** Feed random bits into the pool. */
extern void add_hwgenerator_randomness(const char *buffer, size_t count, size_t entropy);
--
2.2.0.rc0.207.ga3a616c
--
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