| Message ID | 20210223233515.3468677-11-mathieu.poirier@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | remoteproc: Add support for detaching a remote processor | expand |
On 2/24/21 12:35 AM, Mathieu Poirier wrote: > Introduce function rproc_detach() to enable the remoteproc > core to release the resources associated with a remote processor > without stopping its operation. > > Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Reviewed-by: Arnaud Pouliquen <arnaud.pouliquen@st.com> Thanks, > --- > New for V6: > - Checking for rproc->state has been removed. They have been moved to > calling functions. > - Freeing the cache table has been moved to the next patch, i.e 11/16. > --- > > drivers/remoteproc/remoteproc_core.c | 58 +++++++++++++++++++++++++++- > include/linux/remoteproc.h | 1 + > 2 files changed, 58 insertions(+), 1 deletion(-) > > diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c > index 0f680b7ff8f1..fc01b29290a6 100644 > --- a/drivers/remoteproc/remoteproc_core.c > +++ b/drivers/remoteproc/remoteproc_core.c > @@ -1709,7 +1709,7 @@ static int rproc_stop(struct rproc *rproc, bool crashed) > /* > * __rproc_detach(): Does the opposite of __rproc_attach() > */ > -static int __maybe_unused __rproc_detach(struct rproc *rproc) > +static int __rproc_detach(struct rproc *rproc) > { > struct device *dev = &rproc->dev; > int ret; > @@ -1948,6 +1948,62 @@ void rproc_shutdown(struct rproc *rproc) > } > EXPORT_SYMBOL(rproc_shutdown); > > +/** > + * rproc_detach() - Detach the remote processor from the > + * remoteproc core > + * > + * @rproc: the remote processor > + * > + * Detach a remote processor (previously attached to with rproc_attach()). > + * > + * In case @rproc is still being used by an additional user(s), then > + * this function will just decrement the power refcount and exit, > + * without disconnecting the device. > + * > + * Function rproc_detach() calls __rproc_detach() in order to let a remote > + * processor know that services provided by the application processor are > + * no longer available. From there it should be possible to remove the > + * platform driver and even power cycle the application processor (if the HW > + * supports it) without needing to switch off the remote processor. > + */ > +int rproc_detach(struct rproc *rproc) > +{ > + struct device *dev = &rproc->dev; > + int ret; > + > + ret = mutex_lock_interruptible(&rproc->lock); > + if (ret) { > + dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret); > + return ret; > + } > + > + /* if the remote proc is still needed, bail out */ > + if (!atomic_dec_and_test(&rproc->power)) { > + ret = 0; > + goto out; > + } > + > + ret = __rproc_detach(rproc); > + if (ret) { > + atomic_inc(&rproc->power); > + goto out; > + } > + > + /* clean up all acquired resources */ > + rproc_resource_cleanup(rproc); > + > + /* release HW resources if needed */ > + rproc_unprepare_device(rproc); > + > + rproc_disable_iommu(rproc); > + > + rproc->table_ptr = NULL; > +out: > + mutex_unlock(&rproc->lock); > + return ret; > +} > +EXPORT_SYMBOL(rproc_detach); > + > /** > * rproc_get_by_phandle() - find a remote processor by phandle > * @phandle: phandle to the rproc > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h > index eff55ec72e80..e1c843c19cc6 100644 > --- a/include/linux/remoteproc.h > +++ b/include/linux/remoteproc.h > @@ -662,6 +662,7 @@ rproc_of_resm_mem_entry_init(struct device *dev, u32 of_resm_idx, size_t len, > > int rproc_boot(struct rproc *rproc); > void rproc_shutdown(struct rproc *rproc); > +int rproc_detach(struct rproc *rproc); > int rproc_set_firmware(struct rproc *rproc, const char *fw_name); > void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type); > void rproc_coredump_using_sections(struct rproc *rproc); >
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c index 0f680b7ff8f1..fc01b29290a6 100644 --- a/drivers/remoteproc/remoteproc_core.c +++ b/drivers/remoteproc/remoteproc_core.c @@ -1709,7 +1709,7 @@ static int rproc_stop(struct rproc *rproc, bool crashed) /* * __rproc_detach(): Does the opposite of __rproc_attach() */ -static int __maybe_unused __rproc_detach(struct rproc *rproc) +static int __rproc_detach(struct rproc *rproc) { struct device *dev = &rproc->dev; int ret; @@ -1948,6 +1948,62 @@ void rproc_shutdown(struct rproc *rproc) } EXPORT_SYMBOL(rproc_shutdown); +/** + * rproc_detach() - Detach the remote processor from the + * remoteproc core + * + * @rproc: the remote processor + * + * Detach a remote processor (previously attached to with rproc_attach()). + * + * In case @rproc is still being used by an additional user(s), then + * this function will just decrement the power refcount and exit, + * without disconnecting the device. + * + * Function rproc_detach() calls __rproc_detach() in order to let a remote + * processor know that services provided by the application processor are + * no longer available. From there it should be possible to remove the + * platform driver and even power cycle the application processor (if the HW + * supports it) without needing to switch off the remote processor. + */ +int rproc_detach(struct rproc *rproc) +{ + struct device *dev = &rproc->dev; + int ret; + + ret = mutex_lock_interruptible(&rproc->lock); + if (ret) { + dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret); + return ret; + } + + /* if the remote proc is still needed, bail out */ + if (!atomic_dec_and_test(&rproc->power)) { + ret = 0; + goto out; + } + + ret = __rproc_detach(rproc); + if (ret) { + atomic_inc(&rproc->power); + goto out; + } + + /* clean up all acquired resources */ + rproc_resource_cleanup(rproc); + + /* release HW resources if needed */ + rproc_unprepare_device(rproc); + + rproc_disable_iommu(rproc); + + rproc->table_ptr = NULL; +out: + mutex_unlock(&rproc->lock); + return ret; +} +EXPORT_SYMBOL(rproc_detach); + /** * rproc_get_by_phandle() - find a remote processor by phandle * @phandle: phandle to the rproc diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index eff55ec72e80..e1c843c19cc6 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -662,6 +662,7 @@ rproc_of_resm_mem_entry_init(struct device *dev, u32 of_resm_idx, size_t len, int rproc_boot(struct rproc *rproc); void rproc_shutdown(struct rproc *rproc); +int rproc_detach(struct rproc *rproc); int rproc_set_firmware(struct rproc *rproc, const char *fw_name); void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type); void rproc_coredump_using_sections(struct rproc *rproc);
Introduce function rproc_detach() to enable the remoteproc core to release the resources associated with a remote processor without stopping its operation. Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> --- New for V6: - Checking for rproc->state has been removed. They have been moved to calling functions. - Freeing the cache table has been moved to the next patch, i.e 11/16. --- drivers/remoteproc/remoteproc_core.c | 58 +++++++++++++++++++++++++++- include/linux/remoteproc.h | 1 + 2 files changed, 58 insertions(+), 1 deletion(-)