Messages in this thread Patch in this message | | | Date | Mon, 15 Mar 2021 09:03:43 +0000 | From | Cristian Marussi <> | Subject | Re: [PATCH v6 37/37] firmware: arm_scmi: add dynamic scmi devices creation |
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Hi
On Mon, Mar 15, 2021 at 08:33:27AM +0000, Sudeep Holla wrote: > Hi Cristian, > > Sorry for the delay. >
No worries.
> 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. > Ok.
> > > +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. >
Ok I'll do.
> > /** > > * 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 ? >
Answering both of the above, users++ is protected by scmi_list_mutex as it was already and the reason for moving the get in a separate function is to able to call it with mutex alrady acquired, so both here from scmi_handle_get(), which acquires itself that mutex, BUT also from scmi_request_protocol_device() which acquires already the mutex while scanning the list of all the existing scmi instances; it is a sort of get_handle_unlocked but since I changed also the param from dev to info (since I have it already) I named it get_from_info instead. I could add a get_from_info_unlocked(0 to clarify the intent.
I'll rework all of the above and post the whole series on top of for-next-scmi + Jonathan immutable branch locally merged.
Thanks
Cristian
> -- > Regards, > Sudeep
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