> Subject: [PATCH 07/13] remoteproc: Introduce function rproc_detach() > > 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@xxxxxxxxxx> > --- > drivers/remoteproc/remoteproc_core.c | 65 > +++++++++++++++++++++++++++- > include/linux/remoteproc.h | 1 + > 2 files changed, 65 insertions(+), 1 deletion(-) > > diff --git a/drivers/remoteproc/remoteproc_core.c > b/drivers/remoteproc/remoteproc_core.c > index 7a1fc7e0620f..f3943a1e2754 100644 > --- a/drivers/remoteproc/remoteproc_core.c > +++ b/drivers/remoteproc/remoteproc_core.c > @@ -1644,7 +1644,7 @@ 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; > @@ -1887,6 +1887,69 @@ 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_actuate()). > + * > + * 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 (rproc->state != RPROC_RUNNING && rproc->state != > RPROC_ATTACHED) { > + ret = -EPERM; > + goto out; > + } > + > + /* if the remote proc is still needed, bail out */ > + if (!atomic_dec_and_test(&rproc->power)) { > + ret = -EBUSY; > + goto out; > + } > + > + ret = __rproc_detach(rproc); > + if (ret) { > + atomic_inc(&rproc->power); > + goto out; > + } > + > + /* clean up all acquired resources */ > + rproc_resource_cleanup(rproc); > + > + rproc_disable_iommu(rproc); > + > + /* > + * Set the remote processor's table pointer to NULL. Since mapping > + * of the resource table to a virtual address is done in the platform > + * driver, unmapping should also be done there. > + */ > + 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 > 1a57e165da2c..6250491ee851 100644 > --- a/include/linux/remoteproc.h > +++ b/include/linux/remoteproc.h > @@ -656,6 +656,7 @@ 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); > void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type); > int rproc_coredump_add_segment(struct rproc *rproc, dma_addr_t da, size_t > size); int rproc_coredump_add_custom_segment(struct rproc *rproc, > -- Reviewed-by: Peng Fan <peng.fan@xxxxxxx> Not relevant to your patch, just see unregister_virtio_device not set device status when reading code, should that add device status setting in unregister_virtio_device?