6.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sibi Sankar quic_sibis@quicinc.com
commit 94a263f981a3fa3d93f65c31e0fed0756736be43 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/firmware/arm_scmi/driver.c | 76 +++++++++++++++++++--------------- drivers/firmware/arm_scmi/protocols.h | 2 2 files changed, 45 insertions(+), 33 deletions(-)
--- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -1738,6 +1738,39 @@ static int scmi_common_get_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 * a proper custom command payload for each multi-part command request. @@ -1878,6 +1911,7 @@ scmi_common_fastchannel_init(const struc int ret; u32 flags; u64 phys_addr; + u32 attributes; u8 size; void __iomem *addr; struct scmi_xfer *t; @@ -1886,6 +1920,15 @@ scmi_common_fastchannel_init(const struc 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; @@ -2003,39 +2046,6 @@ static void scmi_common_fastchannel_db_r 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, --- 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,