From 8e3c98d9187e09274fc000a7d1a77b070a42d259 Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Thu, 30 Nov 2023 20:43:42 +0000 Subject: [PATCH 1/2] firmware: arm_scmi: Fix frequency truncation by promoting multiplier type Fix the possible frequency truncation for all values equal to or greater 4GHz on 64bit machines by updating the multiplier 'mult_factor' to 'unsigned long' type. It is also possible that the multiplier itself can be greater than or equal to 2^32. So we need to also fix the equation computing the value of the multiplier. Fixes: a9e3fbfaa0ff ("firmware: arm_scmi: add initial support for performance protocol") Reported-by: Sibi Sankar Closes: https://lore.kernel.org/all/20231129065748.19871-3-quic_sibis@quicinc.com/ Cc: Cristian Marussi Link: https://lore.kernel.org/r/20231130204343.503076-1-sudeep.holla@arm.com Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/perf.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c index c2435be0ae1b..f98791274495 100644 --- a/drivers/firmware/arm_scmi/perf.c +++ b/drivers/firmware/arm_scmi/perf.c @@ -152,7 +152,7 @@ struct perf_dom_info { u32 opp_count; u32 sustained_freq_khz; u32 sustained_perf_level; - u32 mult_factor; + unsigned long mult_factor; struct scmi_perf_domain_info info; struct scmi_opp opp[MAX_OPPS]; struct scmi_fc_info *fc_info; @@ -273,8 +273,8 @@ scmi_perf_domain_attributes_get(const struct scmi_protocol_handle *ph, dom_info->mult_factor = 1000; else dom_info->mult_factor = - (dom_info->sustained_freq_khz * 1000) / - dom_info->sustained_perf_level; + (dom_info->sustained_freq_khz * 1000UL) + / dom_info->sustained_perf_level; strscpy(dom_info->info.name, attr->name, SCMI_SHORT_NAME_MAX_SIZE); } From 77f5032e94f244ba08db51e17ca8f37bd7ff9acb Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Thu, 30 Nov 2023 20:43:43 +0000 Subject: [PATCH 2/2] firmware: arm_scmi: Fix possible frequency truncation when using level indexing mode The multiplier is already promoted to unsigned long, however the frequency calculations done when using level indexing mode doesn't use the multiplier computed. It instead hardcodes the multiplier value of 1000 at all the usage sites. Clean that up by assigning the multiplier value of 1000 when using the perf level indexing mode and update the frequency calculations to use the multiplier instead. It should fix the possible frequency truncation for all the values greater than or equal to 4GHz on 64-bit machines. Fixes: 31c7c1397a33 ("firmware: arm_scmi: Add v3.2 perf level indexing mode support") Reported-by: Sibi Sankar Closes: https://lore.kernel.org/all/20231129065748.19871-3-quic_sibis@quicinc.com/ Cc: Cristian Marussi Link: https://lore.kernel.org/r/20231130204343.503076-2-sudeep.holla@arm.com Reviewed-by: Cristian Marussi Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/perf.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c index f98791274495..e11555de99ab 100644 --- a/drivers/firmware/arm_scmi/perf.c +++ b/drivers/firmware/arm_scmi/perf.c @@ -268,7 +268,8 @@ scmi_perf_domain_attributes_get(const struct scmi_protocol_handle *ph, dom_info->sustained_perf_level = le32_to_cpu(attr->sustained_perf_level); if (!dom_info->sustained_freq_khz || - !dom_info->sustained_perf_level) + !dom_info->sustained_perf_level || + dom_info->level_indexing_mode) /* CPUFreq converts to kHz, hence default 1000 */ dom_info->mult_factor = 1000; else @@ -798,7 +799,7 @@ static int scmi_dvfs_device_opps_add(const struct scmi_protocol_handle *ph, if (!dom->level_indexing_mode) freq = dom->opp[idx].perf * dom->mult_factor; else - freq = dom->opp[idx].indicative_freq * 1000; + freq = dom->opp[idx].indicative_freq * dom->mult_factor; data.level = dom->opp[idx].perf; data.freq = freq; @@ -845,7 +846,8 @@ static int scmi_dvfs_freq_set(const struct scmi_protocol_handle *ph, u32 domain, } else { struct scmi_opp *opp; - opp = LOOKUP_BY_FREQ(dom->opps_by_freq, freq / 1000); + opp = LOOKUP_BY_FREQ(dom->opps_by_freq, + freq / dom->mult_factor); if (!opp) return -EIO; @@ -879,7 +881,7 @@ static int scmi_dvfs_freq_get(const struct scmi_protocol_handle *ph, u32 domain, if (!opp) return -EIO; - *freq = opp->indicative_freq * 1000; + *freq = opp->indicative_freq * dom->mult_factor; } return ret; @@ -902,7 +904,7 @@ static int scmi_dvfs_est_power_get(const struct scmi_protocol_handle *ph, if (!dom->level_indexing_mode) opp_freq = opp->perf * dom->mult_factor; else - opp_freq = opp->indicative_freq * 1000; + opp_freq = opp->indicative_freq * dom->mult_factor; if (opp_freq < *freq) continue;