| Message ID | 20250930-rust-next-pwm-working-fan-for-sending-v15-1-5661c3090877@samsung.com |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | Rust Abstractions for PWM subsystem with TH1520 PWM driver | expand |
On Tue, Sep 30, 2025 at 02:20:32PM +0200, Michal Wilczynski wrote: > The upcoming Rust abstraction layer for the PWM subsystem uses a custom > `dev->release` handler to safely manage the lifetime of its driver > data. > > To prevent leaking the memory of the `struct pwm_chip` (allocated by > `pwmchip_alloc`), this custom handler must also call the original > `pwmchip_release` function to complete the cleanup. > > Make `pwmchip_release` a global, exported function so that it can be > called from the Rust FFI bridge. This involves removing the `static` > keyword, adding a prototype to the public header, and exporting the > symbol. > > Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> > Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com> > --- > drivers/pwm/core.c | 3 ++- > include/linux/pwm.h | 6 ++++++ > 2 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c > index 0d66376a83ec350e0c3718959f4d794efd71595a..a33da3dff608fdff91251e5fd07b0dbd295be022 100644 > --- a/drivers/pwm/core.c > +++ b/drivers/pwm/core.c > @@ -1600,12 +1600,13 @@ void pwmchip_put(struct pwm_chip *chip) > } > EXPORT_SYMBOL_GPL(pwmchip_put); > > -static void pwmchip_release(struct device *pwmchip_dev) > +void pwmchip_release(struct device *pwmchip_dev) > { > struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); > > kfree(chip); > } > +EXPORT_SYMBOL_GPL(pwmchip_release); > > struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv) > { > diff --git a/include/linux/pwm.h b/include/linux/pwm.h > index 8cafc483db53addf95591d1ac74287532c0fa0ee..d86061024b52172edf3845bf9252a966f120e365 100644 > --- a/include/linux/pwm.h > +++ b/include/linux/pwm.h > @@ -485,6 +485,12 @@ int __pwmchip_add(struct pwm_chip *chip, struct module *owner); > #define pwmchip_add(chip) __pwmchip_add(chip, THIS_MODULE) > void pwmchip_remove(struct pwm_chip *chip); > > +/* > + * For FFI wrapper use only: > + * The Rust PWM abstraction needs this to properly free the pwm_chip. > + */ > +void pwmchip_release(struct device *dev); > + > int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner); > #define devm_pwmchip_add(dev, chip) __devm_pwmchip_add(dev, chip, THIS_MODULE) > > > -- > 2.34.1 > Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 0d66376a83ec350e0c3718959f4d794efd71595a..a33da3dff608fdff91251e5fd07b0dbd295be022 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -1600,12 +1600,13 @@ void pwmchip_put(struct pwm_chip *chip) } EXPORT_SYMBOL_GPL(pwmchip_put); -static void pwmchip_release(struct device *pwmchip_dev) +void pwmchip_release(struct device *pwmchip_dev) { struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); kfree(chip); } +EXPORT_SYMBOL_GPL(pwmchip_release); struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv) { diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 8cafc483db53addf95591d1ac74287532c0fa0ee..d86061024b52172edf3845bf9252a966f120e365 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -485,6 +485,12 @@ int __pwmchip_add(struct pwm_chip *chip, struct module *owner); #define pwmchip_add(chip) __pwmchip_add(chip, THIS_MODULE) void pwmchip_remove(struct pwm_chip *chip); +/* + * For FFI wrapper use only: + * The Rust PWM abstraction needs this to properly free the pwm_chip. + */ +void pwmchip_release(struct device *dev); + int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner); #define devm_pwmchip_add(dev, chip) __devm_pwmchip_add(dev, chip, THIS_MODULE)