The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 94a263f981a3fa3d93f65c31e0fed0756736be43 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025062018-joyfully-unmixable-8b37@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 94a263f981a3fa3d93f65c31e0fed0756736be43 Mon Sep 17 00:00:00 2001 From: Sibi Sankar quic_sibis@quicinc.com Date: Tue, 29 Apr 2025 15:11:06 +0100 Subject: [PATCH] firmware: arm_scmi: Ensure that the message-id supports fastchannel
Currently the perf and powercap protocol relies on the protocol domain attributes, which just ensures that one fastchannel per domain, before instantiating fastchannels for all possible message-ids. Fix this by ensuring that each message-id supports fastchannel before initialization.
Logs: | scmi: Failed to get FC for protocol 13 [MSG_ID:6 / RES_ID:0] - ret:-95. Using regular messaging | scmi: Failed to get FC for protocol 13 [MSG_ID:6 / RES_ID:1] - ret:-95. Using regular messaging | scmi: Failed to get FC for protocol 13 [MSG_ID:6 / RES_ID:2] - ret:-95. Using regular messaging
CC: stable@vger.kernel.org Reported-by: Johan Hovold johan+linaro@kernel.org Closes: https://lore.kernel.org/lkml/ZoQjAWse2YxwyRJv@hovoldconsulting.com/ Fixes: 6f9ea4dabd2d ("firmware: arm_scmi: Generalize the fast channel support") Reviewed-by: Johan Hovold johan+linaro@kernel.org Tested-by: Johan Hovold johan+linaro@kernel.org Signed-off-by: Sibi Sankar quic_sibis@quicinc.com [Cristian: Modified the condition checked to establish support or not] Signed-off-by: Cristian Marussi cristian.marussi@arm.com Message-Id: 20250429141108.406045-2-cristian.marussi@arm.com Signed-off-by: Sudeep Holla sudeep.holla@arm.com
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 520aa5846916..cf2bc8b8d881 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -1729,6 +1729,39 @@ static int scmi_common_get_max_msg_size(const struct scmi_protocol_handle *ph) return info->desc->max_msg_size; }
+/** + * scmi_protocol_msg_check - Check protocol message attributes + * + * @ph: A reference to the protocol handle. + * @message_id: The ID of the message to check. + * @attributes: A parameter to optionally return the retrieved message + * attributes, in case of Success. + * + * An helper to check protocol message attributes for a specific protocol + * and message pair. + * + * Return: 0 on SUCCESS + */ +static int scmi_protocol_msg_check(const struct scmi_protocol_handle *ph, + u32 message_id, u32 *attributes) +{ + int ret; + struct scmi_xfer *t; + + ret = xfer_get_init(ph, PROTOCOL_MESSAGE_ATTRIBUTES, + sizeof(__le32), 0, &t); + if (ret) + return ret; + + put_unaligned_le32(message_id, t->tx.buf); + ret = do_xfer(ph, t); + if (!ret && attributes) + *attributes = get_unaligned_le32(t->rx.buf); + xfer_put(ph, t); + + return ret; +} + /** * struct scmi_iterator - Iterator descriptor * @msg: A reference to the message TX buffer; filled by @prepare_message with @@ -1870,6 +1903,7 @@ scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, int ret; u32 flags; u64 phys_addr; + u32 attributes; u8 size; void __iomem *addr; struct scmi_xfer *t; @@ -1878,6 +1912,15 @@ scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, struct scmi_msg_resp_desc_fc *resp; const struct scmi_protocol_instance *pi = ph_to_pi(ph);
+ /* Check if the MSG_ID supports fastchannel */ + ret = scmi_protocol_msg_check(ph, message_id, &attributes); + if (ret || !MSG_SUPPORTS_FASTCHANNEL(attributes)) { + dev_dbg(ph->dev, + "Skip FC init for 0x%02X/%d domain:%d - ret:%d\n", + pi->proto->id, message_id, domain, ret); + return; + } + if (!p_addr) { ret = -EINVAL; goto err_out; @@ -1995,39 +2038,6 @@ static void scmi_common_fastchannel_db_ring(struct scmi_fc_db_info *db) SCMI_PROTO_FC_RING_DB(64); }
-/** - * scmi_protocol_msg_check - Check protocol message attributes - * - * @ph: A reference to the protocol handle. - * @message_id: The ID of the message to check. - * @attributes: A parameter to optionally return the retrieved message - * attributes, in case of Success. - * - * An helper to check protocol message attributes for a specific protocol - * and message pair. - * - * Return: 0 on SUCCESS - */ -static int scmi_protocol_msg_check(const struct scmi_protocol_handle *ph, - u32 message_id, u32 *attributes) -{ - int ret; - struct scmi_xfer *t; - - ret = xfer_get_init(ph, PROTOCOL_MESSAGE_ATTRIBUTES, - sizeof(__le32), 0, &t); - if (ret) - return ret; - - put_unaligned_le32(message_id, t->tx.buf); - ret = do_xfer(ph, t); - if (!ret && attributes) - *attributes = get_unaligned_le32(t->rx.buf); - xfer_put(ph, t); - - return ret; -} - static const struct scmi_proto_helpers_ops helpers_ops = { .extended_name_get = scmi_common_extended_name_get, .get_max_msg_size = scmi_common_get_max_msg_size, diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h index aaee57cdcd55..d62c4469d1fd 100644 --- a/drivers/firmware/arm_scmi/protocols.h +++ b/drivers/firmware/arm_scmi/protocols.h @@ -31,6 +31,8 @@
#define SCMI_PROTOCOL_VENDOR_BASE 0x80
+#define MSG_SUPPORTS_FASTCHANNEL(x) ((x) & BIT(0)) + enum scmi_common_cmd { PROTOCOL_VERSION = 0x0, PROTOCOL_ATTRIBUTES = 0x1,