Messages in this thread Patch in this message | | | Date | Mon, 15 Mar 2021 08:33:27 +0000 | From | Sudeep Holla <> | Subject | Re: [PATCH v6 37/37] firmware: arm_scmi: add dynamic scmi devices creation |
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Hi Cristian,
Sorry for the delay.
On Tue, Feb 02, 2021 at 10:15:55PM +0000, Cristian Marussi wrote: > Having added the support for SCMI protocols as modules in order to let > vendors extend the SCMI core with their own additions it seems odd to > then force SCMI drivers built on top to use a static device table to > declare their devices since this way any new SCMI drivers addition > would need the core SCMI device table to be updated too. > > Remove the static core device table and let SCMI drivers to simply declare > which device/protocol pair they need at initialization time: the core will > then take care to generate such devices dynamically during platform > initialization or at module loading time, as long as the requested > underlying protocol is defined in the DT. > > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> > --- > v4 --> v5 > - using klist instead of custom lists > v3 --> v4 > - add a few comments > --- > drivers/firmware/arm_scmi/bus.c | 30 +++ > drivers/firmware/arm_scmi/common.h | 5 + > drivers/firmware/arm_scmi/driver.c | 309 +++++++++++++++++++++++++---- > 3 files changed, 310 insertions(+), 34 deletions(-) > > diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c > index 88e5057f4e85..88149a46e6d9 100644 > --- a/drivers/firmware/arm_scmi/bus.c > +++ b/drivers/firmware/arm_scmi/bus.c > @@ -51,6 +51,31 @@ static int scmi_dev_match(struct device *dev, struct device_driver *drv) > return 0; > } > > +static int scmi_match_by_id_table(struct device *dev, void *data) > +{ > + struct scmi_device *sdev = to_scmi_dev(dev); > + struct scmi_device_id *id_table = data; > + > + return sdev->protocol_id == id_table->protocol_id && > + !strcmp(sdev->name, id_table->name); > +} > + > +struct scmi_device *scmi_find_child_dev(struct device *parent, > + int prot_id, const char *name) > +{ > + struct scmi_device_id id_table; > + struct device *dev; > + > + id_table.protocol_id = prot_id; > + id_table.name = name; > + > + dev = device_find_child(parent, &id_table, scmi_match_by_id_table); > + if (!dev) > + return NULL; > + > + return to_scmi_dev(dev); > +} > + > const struct scmi_protocol *scmi_get_protocol(int protocol_id) > { > const struct scmi_protocol *proto; > @@ -114,6 +139,10 @@ int scmi_driver_register(struct scmi_driver *driver, struct module *owner, > { > int retval; > > + retval = scmi_request_protocol_device(driver->id_table); > + if (retval) > + return retval; > + > driver->driver.bus = &scmi_bus_type; > driver->driver.name = driver->name; > driver->driver.owner = owner; > @@ -130,6 +159,7 @@ EXPORT_SYMBOL_GPL(scmi_driver_register); > void scmi_driver_unregister(struct scmi_driver *driver) > { > driver_unregister(&driver->driver); > + scmi_unrequest_protocol_device(driver->id_table); > } > EXPORT_SYMBOL_GPL(scmi_driver_unregister); > > diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h > index 1e2046c61d43..9a0519db4865 100644 > --- a/drivers/firmware/arm_scmi/common.h > +++ b/drivers/firmware/arm_scmi/common.h > @@ -307,6 +307,11 @@ struct scmi_transport_ops { > bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); > }; > > +int scmi_request_protocol_device(const struct scmi_device_id *id_table); > +void scmi_unrequest_protocol_device(const struct scmi_device_id *id_table);
Sorry for being pedantic, I don't like these names. I would prefer something like scmi_protocol_device_{create,destroy/delete}_request. The action the function does needs to be at the end of the function name. Atleast that is something I follow. I haven't checked all the previous patches, just this function made to look at both the name style and the name itself.
> +struct scmi_device *scmi_find_child_dev(struct device *parent, > + int prot_id, const char *name); > +
scmi_child_dev_find based on what I mentioned above. Please change all other non-static functions even if I have not mentioned. Try to cover all the new functions introduced in this series, existing ones we can take up later.
> /** > * struct scmi_desc - Description of SoC integration > * > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c > index dcdfd94b47f7..9fc979e3b16f 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -21,6 +21,7 @@ > #include <linux/io.h> > #include <linux/kernel.h> > #include <linux/ktime.h> > +#include <linux/list.h> > #include <linux/module.h> > #include <linux/of_address.h> > #include <linux/of_device.h> > @@ -56,6 +57,14 @@ static DEFINE_MUTEX(scmi_list_mutex); > /* Track the unique id for the transfers for debug & profiling purpose */ > static atomic_t transfer_last_id; > > +static DEFINE_IDR(scmi_requested_devices); > +static DEFINE_MUTEX(scmi_requested_devices_mtx); > + > +struct scmi_requested_dev { > + const struct scmi_device_id *id_table; > + struct list_head node; > +}; > + > /** > * struct scmi_xfers_info - Structure to manage transfer information > * > @@ -113,6 +122,8 @@ struct scmi_protocol_instance { > * @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 > + * @active_protocols: IDR storing device_nodes for protocols actually defined > + * in the DT and confirmed as implemented by fw. > * @notify_priv: Pointer to private data structure specific to notifications. > * @node: List head > * @users: Number of users of this instance > @@ -130,6 +141,7 @@ struct scmi_info { > /* Ensure mutual exclusive access to protocols instance array */ > struct mutex protocols_mtx; > u8 *protocols_imp; > + struct idr active_protocols; > void *notify_priv; > struct list_head node; > int users; > @@ -936,6 +948,13 @@ static void scmi_devm_put_protocol(struct scmi_device *sdev, u8 protocol_id) > WARN_ON(ret); > } > > +static inline > +struct scmi_handle *scmi_handle_get_from_info(struct scmi_info *info) > +{ > + info->users++;
Doesn't it race with anything ? I have already forgotten how this is used and in what context this gets called.
> + return &info->handle; > +} > + > /** > * scmi_handle_get() - Get the SCMI handle for a device > * > @@ -957,8 +976,7 @@ struct scmi_handle *scmi_handle_get(struct device *dev) > list_for_each(p, &scmi_list) { > info = list_entry(p, struct scmi_info, node); > if (dev->parent == info->dev) { > - handle = &info->handle; > - info->users++; > + handle = scmi_handle_get_from_info(info);
Ah here it is. Any particular reasons for moving it to separate function ?
-- Regards, Sudeep
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