On Tue, Oct 20, 2020 at 10:46:46PM -0400, Thara Gopinath wrote: > Hi Cristian, > > Thanks for this series! > Hi Thara,
thanks for reviewing. > 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.maru...@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 ? > You're right I spotted this awkward thing but I left it because the whole scmi_protocol_init() is removed later on in this series, moving proto initialization to when the protocol is requested, so it seemed silly to fix code that I'm going to remove as a whole in the same series. Probably I could split the whole series better to avoid this. (or fix it anyway and later removed) > > - 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? > So, basically I introduced a new initialization flow triggered by scmi_acquire_protocol (and later in the series by get_ops), so that protocols won't be anymore initialized by scmi_protocol_init() during dev prove but later on when used effectively (acquire/get_ops) so that I can track their usage, but in this patch I ported only base protocol to this new flow while keeping other protos the old way...so again maybe I could split this series better in V2, maybe merging all these protos changes in one go Regards Cristian > > > -- > Warm Regards > Thara