Messages in this thread | | | Subject | Re: [PATCH 01/11] firmware: arm_scmi: review protocol registration interface | From | Thara Gopinath <> | Date | Tue, 20 Oct 2020 22:46:46 -0400 |
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Hi Cristian,
Thanks for this series!
On 10/14/20 11:05 AM, Cristian Marussi wrote: > Extend common protocol registration routines and provide some new generic > protocols' init/deinit helpers that tracks protocols' users and automatically > perform the proper initialization/de-initialization on demand. > > Convert all protocols to use new registration schema while modifying only Base > protocol to use also the new initialization helpers. > > All other standard protocols' initialization is still umodified and bound to > SCMI devices probing. > > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> > --- > drivers/firmware/arm_scmi/base.c | 10 +- > drivers/firmware/arm_scmi/bus.c | 61 +++++++--- > drivers/firmware/arm_scmi/clock.c | 10 +- > drivers/firmware/arm_scmi/common.h | 31 ++++- > drivers/firmware/arm_scmi/driver.c | 168 +++++++++++++++++++++++++++- > drivers/firmware/arm_scmi/notify.c | 3 +- > drivers/firmware/arm_scmi/perf.c | 10 +- > drivers/firmware/arm_scmi/power.c | 10 +- > drivers/firmware/arm_scmi/reset.c | 10 +- > drivers/firmware/arm_scmi/sensors.c | 10 +- > drivers/firmware/arm_scmi/system.c | 8 +- > include/linux/scmi_protocol.h | 6 +- > 12 files changed, 298 insertions(+), 39 deletions(-) > > diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c > index 017e5d8bd869..f19e08ed4369 100644 > --- a/drivers/firmware/arm_scmi/base.c > +++ b/drivers/firmware/arm_scmi/base.c > @@ -318,7 +318,7 @@ static const struct scmi_event_ops base_event_ops = { > .fill_custom_report = scmi_base_fill_custom_report, > }; > > -int scmi_base_protocol_init(struct scmi_handle *h) > +static int scmi_base_protocol_init(struct scmi_handle *h) > { > int id, ret; > u8 *prot_imp; > @@ -365,3 +365,11 @@ int scmi_base_protocol_init(struct scmi_handle *h) > > return 0; > } > + > +static struct scmi_protocol scmi_base = { > + .id = SCMI_PROTOCOL_BASE, > + .init = &scmi_base_protocol_init, > + .ops = NULL, > +}; > + > +DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(base, scmi_base) > diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c > index 1377ec76a45d..afa2e4818a2b 100644 > --- a/drivers/firmware/arm_scmi/bus.c > +++ b/drivers/firmware/arm_scmi/bus.c > @@ -16,7 +16,7 @@ > #include "common.h" > > static DEFINE_IDA(scmi_bus_id); > -static DEFINE_IDR(scmi_protocols); > +static DEFINE_IDR(scmi_available_protocols); > static DEFINE_SPINLOCK(protocol_lock); > > static const struct scmi_device_id * > @@ -51,13 +51,29 @@ static int scmi_dev_match(struct device *dev, struct device_driver *drv) > return 0; > } > > +const struct scmi_protocol *scmi_get_protocol(int protocol_id) > +{ > + const struct scmi_protocol *proto; > + > + proto = idr_find(&scmi_available_protocols, protocol_id); > + if (!proto) { > + pr_warn("SCMI Protocol 0x%x not found!\n", protocol_id); > + return NULL; > + } > + > + pr_debug("GOT SCMI Protocol 0x%x\n", protocol_id); > + > + return proto; > +} > + > static int scmi_protocol_init(int protocol_id, struct scmi_handle *handle) > { > - scmi_prot_init_fn_t fn = idr_find(&scmi_protocols, protocol_id); > + const struct scmi_protocol *proto; > > - if (unlikely(!fn)) > + proto = idr_find(&scmi_available_protocols, protocol_id); > + if (!proto) > return -EINVAL;
Any reason not to use the above scmi_get_protocol here ?
> - return fn(handle); > + return proto->init(handle); > } > > static int scmi_protocol_dummy_init(struct scmi_handle *handle) > @@ -84,7 +100,7 @@ static int scmi_dev_probe(struct device *dev) > return ret; > > /* Skip protocol initialisation for additional devices */ > - idr_replace(&scmi_protocols, &scmi_protocol_dummy_init, > + idr_replace(&scmi_available_protocols, &scmi_protocol_dummy_init, > scmi_dev->protocol_id); > > return scmi_drv->probe(scmi_dev); > @@ -194,26 +210,45 @@ void scmi_set_handle(struct scmi_device *scmi_dev) > scmi_dev->handle = scmi_handle_get(&scmi_dev->dev); > } > > -int scmi_protocol_register(int protocol_id, scmi_prot_init_fn_t fn) > +int scmi_protocol_register(struct scmi_protocol *proto) > { > int ret; > > + if (!proto) { > + pr_err("invalid protocol\n"); > + return -EINVAL; > + } > + > + if (!proto->init) { > + pr_err("missing .init() for protocol 0x%x\n", proto->id); > + return -EINVAL; > + } > + > spin_lock(&protocol_lock); > - ret = idr_alloc(&scmi_protocols, fn, protocol_id, protocol_id + 1, > - GFP_ATOMIC); > + ret = idr_alloc(&scmi_available_protocols, proto, > + proto->id, proto->id + 1, GFP_ATOMIC); > spin_unlock(&protocol_lock); > - if (ret != protocol_id) > - pr_err("unable to allocate SCMI idr slot, err %d\n", ret); > + if (ret != proto->id) { > + pr_err("unable to allocate SCMI idr slot for 0x%x - err %d\n", > + proto->id, ret); > + return ret; > + } > + > + pr_debug("Registered SCMI Protocol 0x%x\n", proto->id); > > - return ret; > + return 0; > } > EXPORT_SYMBOL_GPL(scmi_protocol_register); > > -void scmi_protocol_unregister(int protocol_id) > +void scmi_protocol_unregister(const struct scmi_protocol *proto) > { > spin_lock(&protocol_lock); > - idr_remove(&scmi_protocols, protocol_id); > + idr_remove(&scmi_available_protocols, proto->id); > spin_unlock(&protocol_lock); > + > + pr_debug("Unregistered SCMI Protocol 0x%x\n", proto->id); > + > + return; > } > EXPORT_SYMBOL_GPL(scmi_protocol_unregister); >
[...]
> diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c > index 3dfd8b6a0ebf..7de994e49884 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -23,6 +23,7 @@ > #include <linux/of_address.h> > #include <linux/of_device.h> > #include <linux/processor.h> > +#include <linux/refcount.h> > #include <linux/slab.h> > > #include "common.h" > @@ -68,6 +69,21 @@ struct scmi_xfers_info { > spinlock_t xfer_lock; > }; > > +/** > + * struct scmi_protocol_instance - Describe an initialized protocol instance. > + * @proto: A reference to the protocol descriptor. > + * @gid: A reference for per-protocol devres management. > + * @users: A refcount to track effective users of this protocol. > + * > + * Each protocol is initialized independently once for each SCMI platform in > + * which is defined by DT and implemented by the SCMI server fw. > + */ > +struct scmi_protocol_instance { > + const struct scmi_protocol *proto; > + void *gid; > + refcount_t users; > +}; > + > /** > * struct scmi_info - Structure representing a SCMI instance > * > @@ -80,6 +96,10 @@ struct scmi_xfers_info { > * @rx_minfo: Universal Receive Message management info > * @tx_idr: IDR object to map protocol id to Tx channel info pointer > * @rx_idr: IDR object to map protocol id to Rx channel info pointer > + * @protocols: An array of protocols' instance descriptors initialized for > + * this SCMI instance: populated on protocol's first attempted > + * usage. > + * @protocols_mtx: A mutex to protect protocols instances initialization. > * @protocols_imp: List of protocols implemented, currently maximum of > * MAX_PROTOCOLS_IMP elements allocated by the base protocol > * @node: List head > @@ -94,6 +114,9 @@ struct scmi_info { > struct scmi_xfers_info rx_minfo; > struct idr tx_idr; > struct idr rx_idr; > + struct scmi_protocol_instance *protocols[SCMI_MAX_PROTO]; > + /* Ensure mutual exclusive access to protocols instance array */ > + struct mutex protocols_mtx; > u8 *protocols_imp; > struct list_head node; > int users; > @@ -519,6 +542,132 @@ int scmi_version_get(const struct scmi_handle *handle, u8 protocol, > return ret; > } > > +/** > + * scmi_get_protocol_instance - Protocol initialization helper. > + * @handle: A reference to the SCMI platform instance. > + * @protocol_id: The protocol being requested. > + * > + * In case the required protocol has never been requested before for this > + * instance, allocate and initialize all the needed structures while handling > + * resource allocation with a dedicated per-protocol devres subgroup. > + * > + * Return: A reference to an initialized protocol instance or error on failure. > + */ > +static struct scmi_protocol_instance * __must_check > +scmi_get_protocol_instance(struct scmi_handle *handle, u8 protocol_id) > +{ > + int ret = -ENOMEM; > + void *gid; > + struct scmi_protocol_instance *pi; > + struct scmi_info *info = handle_to_scmi_info(handle); > + > + mutex_lock(&info->protocols_mtx); > + /* Ensure protocols has been updated */ > + smp_rmb(); > + pi = info->protocols[protocol_id]; > + > + if (!pi) { > + const struct scmi_protocol *proto; > + > + /* Fail if protocol not registered on bus */ > + proto = scmi_get_protocol(protocol_id); > + if (!proto) { > + ret = -EINVAL; > + goto out; > + } > + > + /* Protocol specific devres group */ > + gid = devres_open_group(handle->dev, NULL, GFP_KERNEL); > + if (!gid) > + goto out; > + > + pi = devm_kzalloc(handle->dev, sizeof(*pi), GFP_KERNEL); > + if (!pi) > + goto clean; > + > + pi->gid = gid; > + pi->proto = proto; > + refcount_set(&pi->users, 1); > + /* proto->init is assured NON NULL by scmi_protocol_register */ > + ret = pi->proto->init(handle);
Isnt this already done in scmi_protocol_init? Or rather the init should remain here and there is no need for it to be called from scmi_protocol_init?
-- Warm Regards Thara
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