From nobody Wed Sep 17 05:38:19 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8127DC4332F for ; Thu, 22 Dec 2022 18:51:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235149AbiLVSv3 (ORCPT ); Thu, 22 Dec 2022 13:51:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229752AbiLVSvP (ORCPT ); Thu, 22 Dec 2022 13:51:15 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6CEDA23303 for ; Thu, 22 Dec 2022 10:51:13 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 49F7C2F4; Thu, 22 Dec 2022 10:51:54 -0800 (PST) Received: from e120937-lin.. (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CA72F3FA32; Thu, 22 Dec 2022 10:51:11 -0800 (PST) From: Cristian Marussi To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: sudeep.holla@arm.com, james.quinlan@broadcom.com, f.fainelli@gmail.com, etienne.carriere@linaro.org, vincent.guittot@linaro.org, Ludvig.Parsson@axis.com, cristian.marussi@arm.com Subject: [PATCH 5/9] firmware: arm_scmi: Refactor protocol device creation Date: Thu, 22 Dec 2022 18:50:45 +0000 Message-Id: <20221222185049.737625-6-cristian.marussi@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221222185049.737625-1-cristian.marussi@arm.com> References: <20221222185049.737625-1-cristian.marussi@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Move protocol device request helpers from driver.c compilation unit to bus.c, so reducing the cross interactions between driver.c and bus.c. Get rid of old protocol device creation process as a whole from driver.c and remove also stale SCMI system power unicity checks. While at that make such helpers call into scmi_requested_devices_nh notification chain. Signed-off-by: Cristian Marussi --- Note that this patch disables SCMI device creation, it will be restored later in the series, together with SCMI syspower checks, using a new approach. --- drivers/firmware/arm_scmi/bus.c | 157 ++++++++++++++- drivers/firmware/arm_scmi/common.h | 2 - drivers/firmware/arm_scmi/driver.c | 296 ----------------------------- 3 files changed, 156 insertions(+), 299 deletions(-) diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bu= s.c index bed566f58029..e63cc1194d43 100644 --- a/drivers/firmware/arm_scmi/bus.c +++ b/drivers/firmware/arm_scmi/bus.c @@ -9,6 +9,7 @@ =20 #include #include +#include #include #include #include @@ -20,6 +21,160 @@ EXPORT_SYMBOL_GPL(scmi_requested_devices_nh); =20 static DEFINE_IDA(scmi_bus_id); =20 +static DEFINE_IDR(scmi_requested_devices); +/* Protect access to 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; +}; + +/** + * scmi_protocol_device_request - Helper to request a device + * + * @id_table: A protocol/name pair descriptor for the device to be created. + * + * This helper let an SCMI driver request specific devices identified by t= he + * @id_table to be created for each active SCMI instance. + * + * The requested device name MUST NOT be already existent for any protocol; + * at first the freshly requested @id_table is annotated in the IDR table + * @scmi_requested_devices and then the requested device is advertised to = any + * registered party via the @scmi_requested_devices_nh notification chain. + * + * Return: 0 on Success + */ +static int scmi_protocol_device_request(const struct scmi_device_id *id_ta= ble) +{ + int ret =3D 0; + unsigned int id =3D 0; + struct list_head *head, *phead =3D NULL; + struct scmi_requested_dev *rdev; + + pr_debug("Requesting SCMI device (%s) for protocol %x\n", + id_table->name, id_table->protocol_id); + + /* + * Search for the matching protocol rdev list and then search + * of any existent equally named device...fails if any duplicate found. + */ + mutex_lock(&scmi_requested_devices_mtx); + idr_for_each_entry(&scmi_requested_devices, head, id) { + if (!phead) { + /* A list found registered in the IDR is never empty */ + rdev =3D list_first_entry(head, struct scmi_requested_dev, + node); + if (rdev->id_table->protocol_id =3D=3D + id_table->protocol_id) + phead =3D head; + } + list_for_each_entry(rdev, head, node) { + if (!strcmp(rdev->id_table->name, id_table->name)) { + pr_err("Ignoring duplicate request [%d] %s\n", + rdev->id_table->protocol_id, + rdev->id_table->name); + ret =3D -EINVAL; + goto out; + } + } + } + + /* + * No duplicate found for requested id_table, so let's create a new + * requested device entry for this new valid request. + */ + rdev =3D kzalloc(sizeof(*rdev), GFP_KERNEL); + if (!rdev) { + ret =3D -ENOMEM; + goto out; + } + rdev->id_table =3D id_table; + + /* + * Append the new requested device table descriptor to the head of the + * related protocol list, eventually creating such head if not already + * there. + */ + if (!phead) { + phead =3D kzalloc(sizeof(*phead), GFP_KERNEL); + if (!phead) { + kfree(rdev); + ret =3D -ENOMEM; + goto out; + } + INIT_LIST_HEAD(phead); + + ret =3D idr_alloc(&scmi_requested_devices, (void *)phead, + id_table->protocol_id, + id_table->protocol_id + 1, GFP_KERNEL); + if (ret !=3D id_table->protocol_id) { + pr_err("Failed to save SCMI device - ret:%d\n", ret); + kfree(rdev); + kfree(phead); + ret =3D -EINVAL; + goto out; + } + ret =3D 0; + } + list_add(&rdev->node, phead); + +out: + mutex_unlock(&scmi_requested_devices_mtx); + + if (!ret) + blocking_notifier_call_chain(&scmi_requested_devices_nh, + SCMI_BUS_NOTIFY_DEVICE_REQUEST, + (void *)rdev->id_table); + + return ret; +} + +/** + * scmi_protocol_device_unrequest - Helper to unrequest a device + * + * @id_table: A protocol/name pair descriptor for the device to be unreque= sted. + * + * The unrequested device, described by the provided id_table, is at first + * removed from the IDR @scmi_requested_devices and then the removal is + * advertised to any registered party via the @scmi_requested_devices_nh + * notification chain. + */ +static void scmi_protocol_device_unrequest(const struct scmi_device_id *id= _table) +{ + struct list_head *phead; + + pr_debug("Unrequesting SCMI device (%s) for protocol %x\n", + id_table->name, id_table->protocol_id); + + mutex_lock(&scmi_requested_devices_mtx); + phead =3D idr_find(&scmi_requested_devices, id_table->protocol_id); + if (phead) { + struct scmi_requested_dev *victim, *tmp; + + list_for_each_entry_safe(victim, tmp, phead, node) { + if (!strcmp(victim->id_table->name, id_table->name)) { + list_del(&victim->node); + + mutex_unlock(&scmi_requested_devices_mtx); + blocking_notifier_call_chain(&scmi_requested_devices_nh, + SCMI_BUS_NOTIFY_DEVICE_UNREQUEST, + (void *)victim->id_table); + kfree(victim); + mutex_lock(&scmi_requested_devices_mtx); + break; + } + } + + if (list_empty(phead)) { + idr_remove(&scmi_requested_devices, + id_table->protocol_id); + kfree(phead); + } + } + mutex_unlock(&scmi_requested_devices_mtx); +} + static const struct scmi_device_id * scmi_dev_match_id(struct scmi_device *scmi_dev, struct scmi_driver *scmi_d= rv) { @@ -124,7 +279,7 @@ int scmi_driver_register(struct scmi_driver *driver, st= ruct module *owner, =20 retval =3D driver_register(&driver->driver); if (!retval) - pr_debug("registered new scmi driver %s\n", driver->name); + pr_debug("Registered new scmi driver %s\n", driver->name); =20 return retval; } diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi= /common.h index 7ddae90eb945..0f411679df7e 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -172,8 +172,6 @@ struct scmi_transport_ops { bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); }; =20 -int scmi_protocol_device_request(const struct scmi_device_id *id_table); -void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table); struct scmi_device *scmi_child_dev_find(struct device *parent, int prot_id, const char *name); =20 diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi= /driver.c index 62760bed1645..73f640e9448f 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -61,19 +61,6 @@ static DEFINE_MUTEX(scmi_list_mutex); /* Track the unique id for the transfers for debug & profiling purpose */ static atomic_t transfer_last_id; =20 -static DEFINE_IDR(scmi_requested_devices); -static DEFINE_MUTEX(scmi_requested_devices_mtx); - -/* Track globally the creation of SCMI SystemPower related devices */ -static bool scmi_syspower_registered; -/* Protect access to scmi_syspower_registered */ -static DEFINE_MUTEX(scmi_syspower_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 * @@ -2199,288 +2186,6 @@ static int scmi_channels_setup(struct scmi_info *in= fo) return 0; } =20 -/** - * scmi_get_protocol_device - Helper to get/create an SCMI device. - * - * @np: A device node representing a valid active protocols for the referr= ed - * SCMI instance. - * @info: The referred SCMI instance for which we are getting/creating this - * device. - * @prot_id: The protocol ID. - * @name: The device name. - * - * Referring to the specific SCMI instance identified by @info, this helper - * takes care to return a properly initialized device matching the request= ed - * @proto_id and @name: if device was still not existent it is created as a - * child of the specified SCMI instance @info and its transport properly - * initialized as usual. - * - * Return: A properly initialized scmi device, NULL otherwise. - */ -static inline struct scmi_device * -scmi_get_protocol_device(struct device_node *np, struct scmi_info *info, - int prot_id, const char *name) -{ - struct scmi_device *sdev; - - /* Already created for this parent SCMI instance ? */ - sdev =3D scmi_child_dev_find(info->dev, prot_id, name); - if (sdev) - return sdev; - - mutex_lock(&scmi_syspower_mtx); - if (prot_id =3D=3D SCMI_PROTOCOL_SYSTEM && scmi_syspower_registered) { - dev_warn(info->dev, - "SCMI SystemPower protocol device must be unique !\n"); - mutex_unlock(&scmi_syspower_mtx); - - return NULL; - } - - pr_debug("Creating SCMI device (%s) for protocol %x\n", name, prot_id); - - sdev =3D scmi_device_create(np, info->dev, prot_id, name); - if (!sdev) { - dev_err(info->dev, "failed to create %d protocol device\n", - prot_id); - mutex_unlock(&scmi_syspower_mtx); - - return NULL; - } - - if (prot_id =3D=3D SCMI_PROTOCOL_SYSTEM) - scmi_syspower_registered =3D true; - - mutex_unlock(&scmi_syspower_mtx); - - return sdev; -} - -static inline void -scmi_create_protocol_device(struct device_node *np, struct scmi_info *info, - int prot_id, const char *name) -{ - struct scmi_device *sdev; - - sdev =3D scmi_get_protocol_device(np, info, prot_id, name); - if (!sdev) - return; - - /* setup handle now as the transport is ready */ - scmi_set_handle(sdev); -} - -/** - * scmi_create_protocol_devices - Create devices for all pending requests= for - * this SCMI instance. - * - * @np: The device node describing the protocol - * @info: The SCMI instance descriptor - * @prot_id: The protocol ID - * - * All devices previously requested for this instance (if any) are found a= nd - * created by scanning the proper @&scmi_requested_devices entry. - */ -static void scmi_create_protocol_devices(struct device_node *np, - struct scmi_info *info, int prot_id) -{ - struct list_head *phead; - - mutex_lock(&scmi_requested_devices_mtx); - phead =3D idr_find(&scmi_requested_devices, prot_id); - if (phead) { - struct scmi_requested_dev *rdev; - - list_for_each_entry(rdev, phead, node) - scmi_create_protocol_device(np, info, prot_id, - rdev->id_table->name); - } - mutex_unlock(&scmi_requested_devices_mtx); -} - -/** - * scmi_protocol_device_request - Helper to request a device - * - * @id_table: A protocol/name pair descriptor for the device to be created. - * - * This helper let an SCMI driver request specific devices identified by t= he - * @id_table to be created for each active SCMI instance. - * - * The requested device name MUST NOT be already existent for any protocol; - * at first the freshly requested @id_table is annotated in the IDR table - * @scmi_requested_devices, then a matching device is created for each alr= eady - * active SCMI instance. (if any) - * - * This way the requested device is created straight-away for all the alre= ady - * initialized(probed) SCMI instances (handles) and it remains also annota= ted - * as pending creation if the requesting SCMI driver was loaded before some - * SCMI instance and related transports were available: when such late ins= tance - * is probed, its probe will take care to scan the list of pending request= ed - * devices and create those on its own (see @scmi_create_protocol_devices = and - * its enclosing loop) - * - * Return: 0 on Success - */ -int scmi_protocol_device_request(const struct scmi_device_id *id_table) -{ - int ret =3D 0; - unsigned int id =3D 0; - struct list_head *head, *phead =3D NULL; - struct scmi_requested_dev *rdev; - struct scmi_info *info; - - pr_debug("Requesting SCMI device (%s) for protocol %x\n", - id_table->name, id_table->protocol_id); - - /* - * Search for the matching protocol rdev list and then search - * of any existent equally named device...fails if any duplicate found. - */ - mutex_lock(&scmi_requested_devices_mtx); - idr_for_each_entry(&scmi_requested_devices, head, id) { - if (!phead) { - /* A list found registered in the IDR is never empty */ - rdev =3D list_first_entry(head, struct scmi_requested_dev, - node); - if (rdev->id_table->protocol_id =3D=3D - id_table->protocol_id) - phead =3D head; - } - list_for_each_entry(rdev, head, node) { - if (!strcmp(rdev->id_table->name, id_table->name)) { - pr_err("Ignoring duplicate request [%d] %s\n", - rdev->id_table->protocol_id, - rdev->id_table->name); - ret =3D -EINVAL; - goto out; - } - } - } - - /* - * No duplicate found for requested id_table, so let's create a new - * requested device entry for this new valid request. - */ - rdev =3D kzalloc(sizeof(*rdev), GFP_KERNEL); - if (!rdev) { - ret =3D -ENOMEM; - goto out; - } - rdev->id_table =3D id_table; - - /* - * Append the new requested device table descriptor to the head of the - * related protocol list, eventually creating such head if not already - * there. - */ - if (!phead) { - phead =3D kzalloc(sizeof(*phead), GFP_KERNEL); - if (!phead) { - kfree(rdev); - ret =3D -ENOMEM; - goto out; - } - INIT_LIST_HEAD(phead); - - ret =3D idr_alloc(&scmi_requested_devices, (void *)phead, - id_table->protocol_id, - id_table->protocol_id + 1, GFP_KERNEL); - if (ret !=3D id_table->protocol_id) { - pr_err("Failed to save SCMI device - ret:%d\n", ret); - kfree(rdev); - kfree(phead); - ret =3D -EINVAL; - goto out; - } - ret =3D 0; - } - list_add(&rdev->node, phead); - - /* - * Now effectively create and initialize the requested device for every - * already initialized SCMI instance which has registered the requested - * protocol as a valid active one: i.e. defined in DT and supported by - * current platform FW. - */ - mutex_lock(&scmi_list_mutex); - list_for_each_entry(info, &scmi_list, node) { - struct device_node *child; - - child =3D idr_find(&info->active_protocols, - id_table->protocol_id); - if (child) { - struct scmi_device *sdev; - - sdev =3D scmi_get_protocol_device(child, info, - id_table->protocol_id, - id_table->name); - if (sdev) { - /* Set handle if not already set: device existed */ - if (!sdev->handle) - sdev->handle =3D - scmi_handle_get_from_info_unlocked(info); - /* Relink consumer and suppliers */ - if (sdev->handle) - scmi_device_link_add(&sdev->dev, - sdev->handle->dev); - } - } else { - dev_err(info->dev, - "Failed. SCMI protocol %d not active.\n", - id_table->protocol_id); - } - } - mutex_unlock(&scmi_list_mutex); - -out: - mutex_unlock(&scmi_requested_devices_mtx); - - return ret; -} - -/** - * scmi_protocol_device_unrequest - Helper to unrequest a device - * - * @id_table: A protocol/name pair descriptor for the device to be unreque= sted. - * - * An helper to let an SCMI driver release its request about devices; note= that - * devices are created and initialized once the first SCMI driver request = them - * but they destroyed only on SCMI core unloading/unbinding. - * - * The current SCMI transport layer uses such devices as internal referenc= es and - * as such they could be shared as same transport between multiple drivers= so - * that cannot be safely destroyed till the whole SCMI stack is removed. - * (unless adding further burden of refcounting.) - */ -void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table) -{ - struct list_head *phead; - - pr_debug("Unrequesting SCMI device (%s) for protocol %x\n", - id_table->name, id_table->protocol_id); - - mutex_lock(&scmi_requested_devices_mtx); - phead =3D idr_find(&scmi_requested_devices, id_table->protocol_id); - if (phead) { - struct scmi_requested_dev *victim, *tmp; - - list_for_each_entry_safe(victim, tmp, phead, node) { - if (!strcmp(victim->id_table->name, id_table->name)) { - list_del(&victim->node); - kfree(victim); - break; - } - } - - if (list_empty(phead)) { - idr_remove(&scmi_requested_devices, - id_table->protocol_id); - kfree(phead); - } - } - mutex_unlock(&scmi_requested_devices_mtx); -} - static int scmi_chan_destroy(int id, void *p, void *idr) { struct scmi_chan_info *cinfo =3D p; @@ -2689,7 +2394,6 @@ static int scmi_probe(struct platform_device *pdev) } =20 of_node_get(child); - scmi_create_protocol_devices(child, info, prot_id); } =20 return 0; --=20 2.34.1