From 758cd5fc13b20a5874d33b7d381e78408743f587 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Wed, 31 May 2023 16:20:38 +0100 Subject: firmware: arm_scmi: Add Powercap protocol enable support SCMI powercap protocol v3.2 supports disabling the powercap on a zone by zone basis by providing a zero valued powercap. Expose new operations to enable/disable powercapping on a per-zone base. Signed-off-by: Cristian Marussi Link: https://lore.kernel.org/r/20230531152039.2363181-3-cristian.marussi@arm.com Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/powercap.c | 110 +++++++++++++++++++++++++++++++++-- include/linux/scmi_protocol.h | 18 ++++++ 2 files changed, 122 insertions(+), 6 deletions(-) diff --git a/drivers/firmware/arm_scmi/powercap.c b/drivers/firmware/arm_scmi/powercap.c index 2e490492f187..244929cb4f3e 100644 --- a/drivers/firmware/arm_scmi/powercap.c +++ b/drivers/firmware/arm_scmi/powercap.c @@ -108,6 +108,8 @@ struct scmi_powercap_meas_changed_notify_payld { }; struct scmi_powercap_state { + bool enabled; + u32 last_pcap; bool meas_notif_enabled; u64 thresholds; #define THRESH_LOW(p, id) \ @@ -412,6 +414,10 @@ static int __scmi_powercap_cap_set(const struct scmi_protocol_handle *ph, ignore_dresp); } + /* Save the last explicitly set non-zero powercap value */ + if (PROTOCOL_REV_MAJOR(pi->version) >= 0x2 && !ret && power_cap) + pi->states[domain_id].last_pcap = power_cap; + return ret; } @@ -421,6 +427,20 @@ static int scmi_powercap_cap_set(const struct scmi_protocol_handle *ph, { struct powercap_info *pi = ph->get_priv(ph); + /* + * Disallow zero as a possible explicitly requested powercap: + * there are enable/disable operations for this. + */ + if (!power_cap) + return -EINVAL; + + /* Just log the last set request if acting on a disabled domain */ + if (PROTOCOL_REV_MAJOR(pi->version) >= 0x2 && + !pi->states[domain_id].enabled) { + pi->states[domain_id].last_pcap = power_cap; + return 0; + } + return __scmi_powercap_cap_set(ph, pi, domain_id, power_cap, ignore_dresp); } @@ -589,11 +609,78 @@ scmi_powercap_measurements_threshold_set(const struct scmi_protocol_handle *ph, return ret; } +static int scmi_powercap_cap_enable_set(const struct scmi_protocol_handle *ph, + u32 domain_id, bool enable) +{ + int ret; + u32 power_cap; + struct powercap_info *pi = ph->get_priv(ph); + + if (PROTOCOL_REV_MAJOR(pi->version) < 0x2) + return -EINVAL; + + if (enable == pi->states[domain_id].enabled) + return 0; + + if (enable) { + /* Cannot enable with a zero powercap. */ + if (!pi->states[domain_id].last_pcap) + return -EINVAL; + + ret = __scmi_powercap_cap_set(ph, pi, domain_id, + pi->states[domain_id].last_pcap, + true); + } else { + ret = __scmi_powercap_cap_set(ph, pi, domain_id, 0, true); + } + + if (ret) + return ret; + + /* + * Update our internal state to reflect final platform state: the SCMI + * server could have ignored a disable request and kept enforcing some + * powercap limit requested by other agents. + */ + ret = scmi_powercap_cap_get(ph, domain_id, &power_cap); + if (!ret) + pi->states[domain_id].enabled = !!power_cap; + + return ret; +} + +static int scmi_powercap_cap_enable_get(const struct scmi_protocol_handle *ph, + u32 domain_id, bool *enable) +{ + int ret; + u32 power_cap; + struct powercap_info *pi = ph->get_priv(ph); + + *enable = true; + if (PROTOCOL_REV_MAJOR(pi->version) < 0x2) + return 0; + + /* + * Report always real platform state; platform could have ignored + * a previous disable request. Default true on any error. + */ + ret = scmi_powercap_cap_get(ph, domain_id, &power_cap); + if (!ret) + *enable = !!power_cap; + + /* Update internal state with current real platform state */ + pi->states[domain_id].enabled = *enable; + + return 0; +} + static const struct scmi_powercap_proto_ops powercap_proto_ops = { .num_domains_get = scmi_powercap_num_domains_get, .info_get = scmi_powercap_dom_info_get, .cap_get = scmi_powercap_cap_get, .cap_set = scmi_powercap_cap_set, + .cap_enable_set = scmi_powercap_cap_enable_set, + .cap_enable_get = scmi_powercap_cap_enable_get, .pai_get = scmi_powercap_pai_get, .pai_set = scmi_powercap_pai_set, .measurements_get = scmi_powercap_measurements_get, @@ -854,6 +941,11 @@ scmi_powercap_protocol_init(const struct scmi_protocol_handle *ph) if (!pinfo->powercaps) return -ENOMEM; + pinfo->states = devm_kcalloc(ph->dev, pinfo->num_domains, + sizeof(*pinfo->states), GFP_KERNEL); + if (!pinfo->states) + return -ENOMEM; + /* * Note that any failure in retrieving any domain attribute leads to * the whole Powercap protocol initialization failure: this way the @@ -868,15 +960,21 @@ scmi_powercap_protocol_init(const struct scmi_protocol_handle *ph) if (pinfo->powercaps[domain].fastchannels) scmi_powercap_domain_init_fc(ph, domain, &pinfo->powercaps[domain].fc_info); - } - pinfo->states = devm_kcalloc(ph->dev, pinfo->num_domains, - sizeof(*pinfo->states), GFP_KERNEL); - if (!pinfo->states) - return -ENOMEM; + /* Grab initial state when disable is supported. */ + if (PROTOCOL_REV_MAJOR(version) >= 0x2) { + ret = __scmi_powercap_cap_get(ph, + &pinfo->powercaps[domain], + &pinfo->states[domain].last_pcap); + if (ret) + return ret; - pinfo->version = version; + pinfo->states[domain].enabled = + !!pinfo->states[domain].last_pcap; + } + } + pinfo->version = version; return ph->set_priv(ph, pinfo); } diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h index 0ce5746a4470..e6fe4f73ffe6 100644 --- a/include/linux/scmi_protocol.h +++ b/include/linux/scmi_protocol.h @@ -629,11 +629,25 @@ struct scmi_powercap_info { * @num_domains_get: get the count of powercap domains provided by SCMI. * @info_get: get the information for the specified domain. * @cap_get: get the current CAP value for the specified domain. + * On SCMI platforms supporting powercap zone disabling, this could + * report a zero value for a zone where powercapping is disabled. * @cap_set: set the CAP value for the specified domain to the provided value; * if the domain supports setting the CAP with an asynchronous command * this request will finally trigger an asynchronous transfer, but, if * @ignore_dresp here is set to true, this call will anyway return * immediately without waiting for the related delayed response. + * Note that the powercap requested value must NOT be zero, even if + * the platform supports disabling a powercap by setting its cap to + * zero (since SCMI v3.2): there are dedicated operations that should + * be used for that. (@cap_enable_set/get) + * @cap_enable_set: enable or disable the powercapping on the specified domain, + * if supported by the SCMI platform implementation. + * Note that, by the SCMI specification, the platform can + * silently ignore our disable request and decide to enforce + * anyway some other powercap value requested by another agent + * on the system: for this reason @cap_get and @cap_enable_get + * will always report the final platform view of the powercaps. + * @cap_enable_get: get the current CAP enable status for the specified domain. * @pai_get: get the current PAI value for the specified domain. * @pai_set: set the PAI value for the specified domain to the provided value. * @measurements_get: retrieve the current average power measurements for the @@ -662,6 +676,10 @@ struct scmi_powercap_proto_ops { u32 *power_cap); int (*cap_set)(const struct scmi_protocol_handle *ph, u32 domain_id, u32 power_cap, bool ignore_dresp); + int (*cap_enable_set)(const struct scmi_protocol_handle *ph, + u32 domain_id, bool enable); + int (*cap_enable_get)(const struct scmi_protocol_handle *ph, + u32 domain_id, bool *enable); int (*pai_get)(const struct scmi_protocol_handle *ph, u32 domain_id, u32 *pai); int (*pai_set)(const struct scmi_protocol_handle *ph, u32 domain_id, -- cgit v1.2.3