From: Cristian Marussi <cristian.marussi@arm.com> 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, vincent.guittot@linaro.org, peng.fan@oss.nxp.com, michal.simek@amd.com, quic_sibis@quicinc.com, quic_nkela@quicinc.com, souvik.chakravarty@arm.com, Cristian Marussi <cristian.marussi@arm.com> Subject: [PATCH 2/7] firmware: arm_scmi: Add support for v3.2 NEGOTIATE_PROTOCOL_VERSION Date: Wed, 14 Feb 2024 18:30:01 +0000 [thread overview] Message-ID: <20240214183006.3403207-3-cristian.marussi@arm.com> (raw) In-Reply-To: <20240214183006.3403207-1-cristian.marussi@arm.com> Freshly introduced NEGOTIATE_PROTOCOL_VERSION allows the agent to ascertain upfront if a specific, usually older, protocol version is supported by the platform. It is used by the agent in case the platform has advertised the support of a newer protocol version than the latest version supported by the agent, since backward compatibility cannot be automatically assumed. Emit a warning about possible incompatibility when negotiation was not possible or just print the successfully negotiated protocol. Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- drivers/firmware/arm_scmi/driver.c | 65 ++++++++++++++++++++++++--- drivers/firmware/arm_scmi/protocols.h | 1 + 2 files changed, 61 insertions(+), 5 deletions(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 4a64ad5c21ee..34d77802c990 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -86,6 +86,12 @@ struct scmi_xfers_info { * @users: A refcount to track effective users of this protocol. * @priv: Reference for optional protocol private data. * @version: Protocol version supported by the platform as detected at runtime. + * @negotiated_version: When the platform supports a newer protocol version, + * the agent will try to negotiate with the platform the + * usage of the newest version known to it, since + * backward compatibility is NOT automatically assured. + * This field is NON-zero when a successful negotiation + * has completed. * @ph: An embedded protocol handle that will be passed down to protocol * initialization code to identify this instance. * @@ -99,6 +105,7 @@ struct scmi_protocol_instance { refcount_t users; void *priv; unsigned int version; + unsigned int negotiated_version; struct scmi_protocol_handle ph; }; @@ -1815,6 +1822,44 @@ scmi_revision_area_get(const struct scmi_protocol_handle *ph) return pi->handle->version; } +/** + * scmi_protocol_version_negotiate - Negotiate protocol version + * + * @ph: A reference to the protocol handle. + * + * An helper to negotiate a protocol version different from the latest + * advertised as supported from the platform: on Success backward + * compatibility is assured by the platform. + * + * Return: 0 on Success + */ +static int scmi_protocol_version_negotiate(struct scmi_protocol_handle *ph) +{ + int ret; + struct scmi_xfer *t; + struct scmi_protocol_instance *pi = ph_to_pi(ph); + + /* At first check if NEGOTIATE_PROTOCOL_VERSION is supported ... */ + ret = scmi_protocol_msg_check(ph, NEGOTIATE_PROTOCOL_VERSION, NULL); + if (ret) + return ret; + + /* ... then attempt protocol version negotiation */ + ret = xfer_get_init(ph, NEGOTIATE_PROTOCOL_VERSION, + sizeof(__le32), 0, &t); + if (ret) + return ret; + + put_unaligned_le32(pi->proto->supported_version, t->tx.buf); + ret = do_xfer(ph, t); + if (!ret) + pi->negotiated_version = pi->proto->supported_version; + + xfer_put(ph, t); + + return ret; +} + /** * scmi_alloc_init_protocol_instance - Allocate and initialize a protocol * instance descriptor. @@ -1887,11 +1932,21 @@ scmi_alloc_init_protocol_instance(struct scmi_info *info, devres_close_group(handle->dev, pi->gid); dev_dbg(handle->dev, "Initialized protocol: 0x%X\n", pi->proto->id); - if (pi->version > proto->supported_version) - dev_warn(handle->dev, - "Detected UNSUPPORTED higher version 0x%X for protocol 0x%X." - "Backward compatibility is NOT assured.\n", - pi->version, pi->proto->id); + if (pi->version > proto->supported_version) { + ret = scmi_protocol_version_negotiate(&pi->ph); + if (!ret) { + dev_info(handle->dev, + "Protocol 0x%X successfully negotiated version 0x%X\n", + proto->id, pi->negotiated_version); + } else { + dev_warn(handle->dev, + "Detected UNSUPPORTED higher version 0x%X for protocol 0x%X.\n", + pi->version, pi->proto->id); + dev_warn(handle->dev, + "Trying version 0x%X. Backward compatibility is NOT assured.\n", + pi->proto->supported_version); + } + } return pi; diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h index 26a3edd49fea..693019fff0f6 100644 --- a/drivers/firmware/arm_scmi/protocols.h +++ b/drivers/firmware/arm_scmi/protocols.h @@ -33,6 +33,7 @@ enum scmi_common_cmd { PROTOCOL_VERSION = 0x0, PROTOCOL_ATTRIBUTES = 0x1, PROTOCOL_MESSAGE_ATTRIBUTES = 0x2, + NEGOTIATE_PROTOCOL_VERSION = 0x10, }; /** -- 2.43.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Cristian Marussi <cristian.marussi@arm.com> 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, vincent.guittot@linaro.org, peng.fan@oss.nxp.com, michal.simek@amd.com, quic_sibis@quicinc.com, quic_nkela@quicinc.com, souvik.chakravarty@arm.com, Cristian Marussi <cristian.marussi@arm.com> Subject: [PATCH 2/7] firmware: arm_scmi: Add support for v3.2 NEGOTIATE_PROTOCOL_VERSION Date: Wed, 14 Feb 2024 18:30:01 +0000 [thread overview] Message-ID: <20240214183006.3403207-3-cristian.marussi@arm.com> (raw) In-Reply-To: <20240214183006.3403207-1-cristian.marussi@arm.com> Freshly introduced NEGOTIATE_PROTOCOL_VERSION allows the agent to ascertain upfront if a specific, usually older, protocol version is supported by the platform. It is used by the agent in case the platform has advertised the support of a newer protocol version than the latest version supported by the agent, since backward compatibility cannot be automatically assumed. Emit a warning about possible incompatibility when negotiation was not possible or just print the successfully negotiated protocol. Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- drivers/firmware/arm_scmi/driver.c | 65 ++++++++++++++++++++++++--- drivers/firmware/arm_scmi/protocols.h | 1 + 2 files changed, 61 insertions(+), 5 deletions(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 4a64ad5c21ee..34d77802c990 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -86,6 +86,12 @@ struct scmi_xfers_info { * @users: A refcount to track effective users of this protocol. * @priv: Reference for optional protocol private data. * @version: Protocol version supported by the platform as detected at runtime. + * @negotiated_version: When the platform supports a newer protocol version, + * the agent will try to negotiate with the platform the + * usage of the newest version known to it, since + * backward compatibility is NOT automatically assured. + * This field is NON-zero when a successful negotiation + * has completed. * @ph: An embedded protocol handle that will be passed down to protocol * initialization code to identify this instance. * @@ -99,6 +105,7 @@ struct scmi_protocol_instance { refcount_t users; void *priv; unsigned int version; + unsigned int negotiated_version; struct scmi_protocol_handle ph; }; @@ -1815,6 +1822,44 @@ scmi_revision_area_get(const struct scmi_protocol_handle *ph) return pi->handle->version; } +/** + * scmi_protocol_version_negotiate - Negotiate protocol version + * + * @ph: A reference to the protocol handle. + * + * An helper to negotiate a protocol version different from the latest + * advertised as supported from the platform: on Success backward + * compatibility is assured by the platform. + * + * Return: 0 on Success + */ +static int scmi_protocol_version_negotiate(struct scmi_protocol_handle *ph) +{ + int ret; + struct scmi_xfer *t; + struct scmi_protocol_instance *pi = ph_to_pi(ph); + + /* At first check if NEGOTIATE_PROTOCOL_VERSION is supported ... */ + ret = scmi_protocol_msg_check(ph, NEGOTIATE_PROTOCOL_VERSION, NULL); + if (ret) + return ret; + + /* ... then attempt protocol version negotiation */ + ret = xfer_get_init(ph, NEGOTIATE_PROTOCOL_VERSION, + sizeof(__le32), 0, &t); + if (ret) + return ret; + + put_unaligned_le32(pi->proto->supported_version, t->tx.buf); + ret = do_xfer(ph, t); + if (!ret) + pi->negotiated_version = pi->proto->supported_version; + + xfer_put(ph, t); + + return ret; +} + /** * scmi_alloc_init_protocol_instance - Allocate and initialize a protocol * instance descriptor. @@ -1887,11 +1932,21 @@ scmi_alloc_init_protocol_instance(struct scmi_info *info, devres_close_group(handle->dev, pi->gid); dev_dbg(handle->dev, "Initialized protocol: 0x%X\n", pi->proto->id); - if (pi->version > proto->supported_version) - dev_warn(handle->dev, - "Detected UNSUPPORTED higher version 0x%X for protocol 0x%X." - "Backward compatibility is NOT assured.\n", - pi->version, pi->proto->id); + if (pi->version > proto->supported_version) { + ret = scmi_protocol_version_negotiate(&pi->ph); + if (!ret) { + dev_info(handle->dev, + "Protocol 0x%X successfully negotiated version 0x%X\n", + proto->id, pi->negotiated_version); + } else { + dev_warn(handle->dev, + "Detected UNSUPPORTED higher version 0x%X for protocol 0x%X.\n", + pi->version, pi->proto->id); + dev_warn(handle->dev, + "Trying version 0x%X. Backward compatibility is NOT assured.\n", + pi->proto->supported_version); + } + } return pi; diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h index 26a3edd49fea..693019fff0f6 100644 --- a/drivers/firmware/arm_scmi/protocols.h +++ b/drivers/firmware/arm_scmi/protocols.h @@ -33,6 +33,7 @@ enum scmi_common_cmd { PROTOCOL_VERSION = 0x0, PROTOCOL_ATTRIBUTES = 0x1, PROTOCOL_MESSAGE_ATTRIBUTES = 0x2, + NEGOTIATE_PROTOCOL_VERSION = 0x10, }; /** -- 2.43.0
next prev parent reply other threads:[~2024-02-14 18:31 UTC|newest] Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-02-14 18:29 [PATCH 0/7] SCMI V3.2 Misc updates Cristian Marussi 2024-02-14 18:29 ` Cristian Marussi 2024-02-14 18:30 ` [PATCH 1/7] firmware: arm_scmi: Add a common helper to check if a message is supported Cristian Marussi 2024-02-14 18:30 ` Cristian Marussi 2024-02-14 18:30 ` Cristian Marussi [this message] 2024-02-14 18:30 ` [PATCH 2/7] firmware: arm_scmi: Add support for v3.2 NEGOTIATE_PROTOCOL_VERSION Cristian Marussi 2024-02-14 18:30 ` [PATCH 3/7] firmware: arm_scmi: Add Clock check for extended config support Cristian Marussi 2024-02-14 18:30 ` Cristian Marussi 2024-02-14 18:30 ` [PATCH 4/7] firmware: arm_scmi: Add standard Clock OEM definitions Cristian Marussi 2024-02-14 18:30 ` Cristian Marussi 2024-02-14 18:30 ` [PATCH 5/7] firmware: arm_scmi: Update supported Clock protocol version Cristian Marussi 2024-02-14 18:30 ` Cristian Marussi 2024-02-14 18:30 ` [PATCH 6/7] clk: scmi: Allocate CLK operations dynamically Cristian Marussi 2024-02-14 18:30 ` Cristian Marussi 2024-02-22 5:44 ` Stephen Boyd 2024-02-22 5:44 ` Stephen Boyd 2024-02-22 8:28 ` Cristian Marussi 2024-02-22 8:28 ` Cristian Marussi 2024-02-29 2:20 ` Stephen Boyd 2024-02-29 2:20 ` Stephen Boyd 2024-02-29 10:09 ` Cristian Marussi 2024-02-29 10:09 ` Cristian Marussi 2024-02-14 18:30 ` [PATCH 7/7] clk: scmi: Support get/set duty_cycle operations Cristian Marussi 2024-02-14 18:30 ` Cristian Marussi 2024-02-22 5:44 ` Stephen Boyd 2024-02-22 5:44 ` Stephen Boyd 2024-02-22 9:37 ` (subset) [PATCH 0/7] SCMI V3.2 Misc updates Sudeep Holla 2024-02-22 9:37 ` Sudeep Holla
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20240214183006.3403207-3-cristian.marussi@arm.com \ --to=cristian.marussi@arm.com \ --cc=f.fainelli@gmail.com \ --cc=james.quinlan@broadcom.com \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-kernel@vger.kernel.org \ --cc=michal.simek@amd.com \ --cc=peng.fan@oss.nxp.com \ --cc=quic_nkela@quicinc.com \ --cc=quic_sibis@quicinc.com \ --cc=souvik.chakravarty@arm.com \ --cc=sudeep.holla@arm.com \ --cc=vincent.guittot@linaro.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.