On Fri, May 24, 2024 at 06:26:42PM GMT, Chris Lew wrote:
> Add qcom_smem_bust_hwspin_lock_by_host to enable remoteproc to bust the
> hwspin_lock owned by smem. In the event the remoteproc crashes
> unexpectedly, the remoteproc driver can invoke this API to try and bust
> the hwspin_lock and release the lock if still held by the remoteproc
> device.
>
> Signed-off-by: Chris Lew <quic_clew@xxxxxxxxxxx>
> ---
> drivers/soc/qcom/smem.c | 28 ++++++++++++++++++++++++++++
> include/linux/soc/qcom/smem.h | 2 ++
> 2 files changed, 30 insertions(+)
>
> diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
> index 7191fa0c087f..683599990387 100644
> --- a/drivers/soc/qcom/smem.c
> +++ b/drivers/soc/qcom/smem.c
> @@ -359,6 +359,34 @@ static struct qcom_smem *__smem;
> /* Timeout (ms) for the trylock of remote spinlocks */
> #define HWSPINLOCK_TIMEOUT 1000
>
> +/* The qcom hwspinlock id is always plus one from the smem host id */
> +#define SMEM_HOST_ID_TO_HWSPINLOCK_ID(__x) ((__x) + 1)
> +
> +/**
> + * qcom_smem_bust_hwspin_lock_by_host() - bust the smem hwspinlock for an smem host id
> + * @host: remote processor id
> + *
> + * Busts the hwspin_lock for the given smem host id. This helper is intended for remoteproc drivers
> + * that manage remoteprocs with an equivalent smem driver instance in the remote firmware. Drivers
> + * can force a release of the smem hwspin_lock if the rproc unexpectedly goes into a bad state.
Please wrap these at 80 characters.
> + *
> + * Context: Process context.
> + *
> + * Returns: 0 on success, otherwise negative errno.
> + */
> +int qcom_smem_bust_hwspin_lock_by_host(unsigned host)
> +{
> + if (!__smem)
> + return -EPROBE_DEFER;
This would be called at a time where -EPROBE_DEFER isn't appropriate,
the client should invoke qcom_smem_is_available() at probe time to guard
against this.
> +
> + /* This function is for remote procs, so ignore SMEM_HOST_APPS */
> + if (host == SMEM_HOST_APPS ||host >= SMEM_HOST_COUNT)
Missing <space> after ||
Regards,
Bjorn
> + return -EINVAL;
> +
> + return hwspin_lock_bust(__smem->hwlock, SMEM_HOST_ID_TO_HWSPINLOCK_ID(host));
> +}
> +EXPORT_SYMBOL_GPL(qcom_smem_bust_hwspin_lock_by_host);
> +
> /**
> * qcom_smem_is_available() - Check if SMEM is available
> *
> diff --git a/include/linux/soc/qcom/smem.h b/include/linux/soc/qcom/smem.h
> index a36a3b9d4929..959eea0812bb 100644
> --- a/include/linux/soc/qcom/smem.h
> +++ b/include/linux/soc/qcom/smem.h
> @@ -14,4 +14,6 @@ phys_addr_t qcom_smem_virt_to_phys(void *p);
>
> int qcom_smem_get_soc_id(u32 *id);
>
> +int qcom_smem_bust_hwspin_lock_by_host(unsigned host);
> +
> #endif
>
> --
> 2.25.1
>
