From 07cb8c324b63c3e09245b9a8c4ca805a8ca1c8e6 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Mon, 10 Mar 2025 18:08:11 +0000 Subject: [PATCH] firmware: arm_scmi: Add polling support to raw mode Provide a couple of additional debugfs entries to enable polling-mode on the waiting path of injected messages: message_poll will cause the system to poll while waiting for the reply, while message_poll_async will send an asynchronous message, as usual, and will use polling mode for the immediate synchronous part of the async command. Signed-off-by: Cristian Marussi Message-Id: <20250310180811.1463539-1-cristian.marussi@arm.com> Signed-off-by: Sudeep Holla --- Documentation/ABI/testing/debugfs-scmi-raw | 91 ++++++++++++++++++++++ drivers/firmware/arm_scmi/driver.c | 3 +- drivers/firmware/arm_scmi/raw_mode.c | 72 +++++++++++++++-- 3 files changed, 160 insertions(+), 6 deletions(-) diff --git a/Documentation/ABI/testing/debugfs-scmi-raw b/Documentation/ABI/testing/debugfs-scmi-raw index 97678cc9535c..5847b96b3896 100644 --- a/Documentation/ABI/testing/debugfs-scmi-raw +++ b/Documentation/ABI/testing/debugfs-scmi-raw @@ -31,6 +31,42 @@ Description: SCMI Raw asynchronous message injection/snooping facility; write (receiving an EOF at each message boundary). Users: Debugging, any userspace test suite +What: /sys/kernel/debug/scmi//raw/message_poll +Date: June 2025 +KernelVersion: 6.16 +Contact: cristian.marussi@arm.com +Description: SCMI Raw message injection/snooping facility using polling mode; + write a complete SCMI command message (header included) in + little-endian binary format to have it sent to the configured + backend SCMI server for instance , using polling mode on + the reception path. (if transport is polling capable) + Any subsequently received response can be read from this same + entry if it arrived within the configured timeout. + Each write to the entry causes one command request to be built + and sent while the replies are read back one message at time + (receiving an EOF at each message boundary). +Users: Debugging, any userspace test suite + +What: /sys/kernel/debug/scmi//raw/message_poll_async +Date: June 2025 +KernelVersion: 6.16 +Contact: cristian.marussi@arm.com +Description: SCMI Raw asynchronous message injection/snooping facility using + polling-mode; write a complete SCMI asynchronous command message + (header included) in little-endian binary format to have it sent + to the configured backend SCMI server for instance , using + polling-mode on the reception path of the immediate part of the + asynchronous command. (if transport is polling capable) + Any subsequently received response can be read from this same + entry if it arrived within the configured timeout. + Any additional delayed response received afterwards can be read + from this same entry too if it arrived within the configured + timeout. + Each write to the entry causes one command request to be built + and sent while the replies are read back one message at time + (receiving an EOF at each message boundary). +Users: Debugging, any userspace test suite + What: /sys/kernel/debug/scmi//raw/errors Date: March 2023 KernelVersion: 6.3 @@ -115,3 +151,58 @@ Description: SCMI Raw asynchronous message injection/snooping facility; write exist only if the transport is configured to have more than one default channel. Users: Debugging, any userspace test suite + + +What: /sys/kernel/debug/scmi//raw/channels//message_poll +Date: June 2025 +KernelVersion: 6.16 +Contact: cristian.marussi@arm.com +Description: SCMI Raw message injection/snooping facility using polling mode; + write a complete SCMI command message (header included) in + little-endian binary format to have it sent to the configured + backend SCMI server for instance through the transport + channel, using polling mode on the reception path. + (if transport is polling capable) + Any subsequently received response can be read from this same + entry if it arrived on channel within the configured + timeout. + Each write to the entry causes one command request to be built + and sent while the replies are read back one message at time + (receiving an EOF at each message boundary). + Channel identifier matches the SCMI protocol number which + has been associated with this transport channel in the DT + description, with base protocol number 0x10 being the default + channel for this instance. + Note that these per-channel entries rooted at <..>/channels + exist only if the transport is configured to have more than + one default channel. +Users: Debugging, any userspace test suite + +What: /sys/kernel/debug/scmi//raw/channels//message_poll_async +Date: June 2025 +KernelVersion: 6.16 +Contact: cristian.marussi@arm.com +Description: SCMI Raw asynchronous message injection/snooping facility using + polling-mode; write a complete SCMI asynchronous command message + (header included) in little-endian binary format to have it sent + to the configured backend SCMI server for instance through + the transport channel, using polling mode on the reception + path of the immediate part of the asynchronous command. + (if transport is polling capable) + Any subsequently received response can be read from this same + entry if it arrived on channel within the configured + timeout. + Any additional delayed response received afterwards can be read + from this same entry too if it arrived within the configured + timeout. + Each write to the entry causes one command request to be built + and sent while the replies are read back one message at time + (receiving an EOF at each message boundary). + Channel identifier matches the SCMI protocol number which + has been associated with this transport channel in the DT + description, with base protocol number 0x10 being the default + channel for this instance. + Note that these per-channel entries rooted at <..>/channels + exist only if the transport is configured to have more than + one default channel. +Users: Debugging, any userspace test suite diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 43cd410d94f0..520aa5846916 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -1184,7 +1184,8 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo, * RX path since it will be already queued at the end of the TX * poll loop. */ - if (!xfer->hdr.poll_completion) + if (!xfer->hdr.poll_completion || + xfer->hdr.type == MSG_TYPE_DELAYED_RESP) scmi_raw_message_report(info->raw, xfer, SCMI_RAW_REPLY_QUEUE, cinfo->id); diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c index 7cc0d616b8de..3d543b1d8947 100644 --- a/drivers/firmware/arm_scmi/raw_mode.c +++ b/drivers/firmware/arm_scmi/raw_mode.c @@ -671,11 +671,13 @@ static int scmi_do_xfer_raw_start(struct scmi_raw_mode_info *raw, * @len: Length of the message in @buf. * @chan_id: The channel ID to use. * @async: A flag stating if an asynchronous command is required. + * @poll: A flag stating if a polling transmission is required. * * Return: 0 on Success */ static int scmi_raw_message_send(struct scmi_raw_mode_info *raw, - void *buf, size_t len, u8 chan_id, bool async) + void *buf, size_t len, u8 chan_id, + bool async, bool poll) { int ret; struct scmi_xfer *xfer; @@ -684,6 +686,16 @@ static int scmi_raw_message_send(struct scmi_raw_mode_info *raw, if (ret) return ret; + if (poll) { + if (is_transport_polling_capable(raw->desc)) { + xfer->hdr.poll_completion = true; + } else { + dev_err(raw->handle->dev, + "Failed to send RAW message - Polling NOT supported\n"); + return -EINVAL; + } + } + ret = scmi_do_xfer_raw_start(raw, xfer, chan_id, async); if (ret) scmi_xfer_raw_put(raw->handle, xfer); @@ -801,7 +813,7 @@ static ssize_t scmi_dbg_raw_mode_common_read(struct file *filp, static ssize_t scmi_dbg_raw_mode_common_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos, - bool async) + bool async, bool poll) { int ret; struct scmi_dbg_raw_data *rd = filp->private_data; @@ -831,7 +843,7 @@ static ssize_t scmi_dbg_raw_mode_common_write(struct file *filp, } ret = scmi_raw_message_send(rd->raw, rd->tx.buf, rd->tx_size, - rd->chan_id, async); + rd->chan_id, async, poll); /* Reset ppos for next message ... */ rd->tx_size = 0; @@ -875,7 +887,8 @@ static ssize_t scmi_dbg_raw_mode_message_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos) { - return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos, false); + return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos, + false, false); } static __poll_t scmi_dbg_raw_mode_message_poll(struct file *filp, @@ -964,7 +977,8 @@ static ssize_t scmi_dbg_raw_mode_message_async_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos) { - return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos, true); + return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos, + true, false); } static const struct file_operations scmi_dbg_raw_mode_message_async_fops = { @@ -976,6 +990,40 @@ static const struct file_operations scmi_dbg_raw_mode_message_async_fops = { .owner = THIS_MODULE, }; +static ssize_t scmi_dbg_raw_mode_message_poll_write(struct file *filp, + const char __user *buf, + size_t count, loff_t *ppos) +{ + return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos, + false, true); +} + +static const struct file_operations scmi_dbg_raw_mode_message_poll_fops = { + .open = scmi_dbg_raw_mode_open, + .release = scmi_dbg_raw_mode_release, + .read = scmi_dbg_raw_mode_message_read, + .write = scmi_dbg_raw_mode_message_poll_write, + .poll = scmi_dbg_raw_mode_message_poll, + .owner = THIS_MODULE, +}; + +static ssize_t scmi_dbg_raw_mode_message_poll_async_write(struct file *filp, + const char __user *buf, + size_t count, loff_t *ppos) +{ + return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos, + true, true); +} + +static const struct file_operations scmi_dbg_raw_mode_message_poll_async_fops = { + .open = scmi_dbg_raw_mode_open, + .release = scmi_dbg_raw_mode_release, + .read = scmi_dbg_raw_mode_message_read, + .write = scmi_dbg_raw_mode_message_poll_async_write, + .poll = scmi_dbg_raw_mode_message_poll, + .owner = THIS_MODULE, +}; + static ssize_t scmi_test_dbg_raw_mode_notif_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) @@ -1199,6 +1247,12 @@ void *scmi_raw_mode_init(const struct scmi_handle *handle, debugfs_create_file("message_async", 0600, raw->dentry, raw, &scmi_dbg_raw_mode_message_async_fops); + debugfs_create_file("message_poll", 0600, raw->dentry, raw, + &scmi_dbg_raw_mode_message_poll_fops); + + debugfs_create_file("message_poll_async", 0600, raw->dentry, raw, + &scmi_dbg_raw_mode_message_poll_async_fops); + debugfs_create_file("notification", 0400, raw->dentry, raw, &scmi_dbg_raw_mode_notification_fops); @@ -1230,6 +1284,14 @@ void *scmi_raw_mode_init(const struct scmi_handle *handle, debugfs_create_file_aux_num("message_async", 0600, chd, raw, channels[i], &scmi_dbg_raw_mode_message_async_fops); + + debugfs_create_file_aux_num("message_poll", 0600, chd, + raw, channels[i], + &scmi_dbg_raw_mode_message_poll_fops); + + debugfs_create_file_aux_num("message_poll_async", 0600, + chd, raw, channels[i], + &scmi_dbg_raw_mode_message_poll_async_fops); } } -- 2.25.1