On Fri 18 Jun 06:15 CDT 2021, Stephan Gerhold wrote: > It is easy to forget to call qcom_smem_state_put() after > a qcom_smem_state_get(). Introduce a devm_qcom_smem_state_get() > helper function that automates this so that qcom_smem_state_put() > is automatically called when a device is removed. > Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> Regards, Bjorn > Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx> > --- > I use this in my WIP bam-dmux driver, so it might simplify coordination > later if we can somehow get this in for 5.14 (if it isn't too late yet). > > Similar code can be found in clk-devres.c for example: > https://elixir.bootlin.com/linux/v5.13-rc6/source/drivers/clk/clk-devres.c#L7 > --- > drivers/soc/qcom/smem_state.c | 36 +++++++++++++++++++++++++++++ > include/linux/soc/qcom/smem_state.h | 7 ++++++ > 2 files changed, 43 insertions(+) > > diff --git a/drivers/soc/qcom/smem_state.c b/drivers/soc/qcom/smem_state.c > index d2b558438deb..31faf4aa868e 100644 > --- a/drivers/soc/qcom/smem_state.c > +++ b/drivers/soc/qcom/smem_state.c > @@ -151,6 +151,42 @@ void qcom_smem_state_put(struct qcom_smem_state *state) > } > EXPORT_SYMBOL_GPL(qcom_smem_state_put); > > +static void devm_qcom_smem_state_release(struct device *dev, void *res) > +{ > + qcom_smem_state_put(*(struct qcom_smem_state **)res); > +} > + > +/** > + * devm_qcom_smem_state_get() - acquire handle to a devres managed state > + * @dev: client device pointer > + * @con_id: name of the state to lookup > + * @bit: flags from the state reference, indicating which bit's affected > + * > + * Returns handle to the state, or ERR_PTR(). qcom_smem_state_put() is called > + * automatically when @dev is removed. > + */ > +struct qcom_smem_state *devm_qcom_smem_state_get(struct device *dev, > + const char *con_id, > + unsigned *bit) > +{ > + struct qcom_smem_state **ptr, *state; > + > + ptr = devres_alloc(devm_qcom_smem_state_release, sizeof(*ptr), GFP_KERNEL); > + if (!ptr) > + return ERR_PTR(-ENOMEM); > + > + state = qcom_smem_state_get(dev, con_id, bit); > + if (!IS_ERR(state)) { > + *ptr = state; > + devres_add(dev, ptr); > + } else { > + devres_free(ptr); > + } > + > + return state; > +} > +EXPORT_SYMBOL_GPL(devm_qcom_smem_state_get); > + > /** > * qcom_smem_state_register() - register a new state > * @of_node: of_node used for matching client lookups > diff --git a/include/linux/soc/qcom/smem_state.h b/include/linux/soc/qcom/smem_state.h > index 63ad8cddad14..17c56a50302f 100644 > --- a/include/linux/soc/qcom/smem_state.h > +++ b/include/linux/soc/qcom/smem_state.h > @@ -14,6 +14,7 @@ struct qcom_smem_state_ops { > #ifdef CONFIG_QCOM_SMEM_STATE > > struct qcom_smem_state *qcom_smem_state_get(struct device *dev, const char *con_id, unsigned *bit); > +struct qcom_smem_state *devm_qcom_smem_state_get(struct device *dev, const char *con_id, unsigned *bit); > void qcom_smem_state_put(struct qcom_smem_state *); > > int qcom_smem_state_update_bits(struct qcom_smem_state *state, u32 mask, u32 value); > @@ -29,6 +30,12 @@ static inline struct qcom_smem_state *qcom_smem_state_get(struct device *dev, > return ERR_PTR(-EINVAL); > } > > +static inline struct qcom_smem_state *devm_qcom_smem_state_get(struct device *dev, > + const char *con_id, unsigned *bit) > +{ > + return ERR_PTR(-EINVAL); > +} > + > static inline void qcom_smem_state_put(struct qcom_smem_state *state) > { > } > -- > 2.32.0 >
