From a2a9d1850060e5d995136561d76e81d61414f076 Mon Sep 17 00:00:00 2001 From: Perry Yuan Date: Mon, 15 Aug 2022 00:35:48 +0800 Subject: ACPI: CPPC: Add ACPI disabled check to acpi_cpc_valid() Make acpi_cpc_valid() check if ACPI is disabled, so that its callers don't need to check that separately. This will also cause the AMD pstate driver to refuse to load right away when ACPI is disabled. Also update the warning message in amd_pstate_init() to mention the ACPI disabled case for completeness. Signed-off-by: Perry Yuan [ rjw: Subject edits, new changelog ] Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/amd-pstate.c | 2 +- drivers/cpufreq/cppc_cpufreq.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/cpufreq') diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 9ac75c1cde9c..a8e386d67a18 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -673,7 +673,7 @@ static int __init amd_pstate_init(void) return -ENODEV; if (!acpi_cpc_valid()) { - pr_debug("the _CPC object is not present in SBIOS\n"); + pr_warn_once("the _CPC object is not present in SBIOS or ACPI disabled\n"); return -ENODEV; } diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index 24eaf0ec344d..9adb7612993e 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -947,7 +947,7 @@ static int __init cppc_cpufreq_init(void) { int ret; - if ((acpi_disabled) || !acpi_cpc_valid()) + if (!acpi_cpc_valid()) return -ENODEV; cppc_check_hisi_workaround(); -- cgit v1.2.3 From ae2df912d1a557a3548be83da20851ac55f42ab3 Mon Sep 17 00:00:00 2001 From: Jeremy Linton Date: Mon, 12 Sep 2022 15:37:22 -0500 Subject: ACPI: CPPC: Disable FIE if registers in PCC regions PCC regions utilize a mailbox to set/retrieve register values used by the CPPC code. This is fine as long as the operations are infrequent. With the FIE code enabled though the overhead can range from 2-11% of system CPU overhead (ex: as measured by top) on Arm based machines. So, before enabling FIE assure none of the registers used by cppc_get_perf_ctrs() are in the PCC region. Finally, add a module parameter which can override the PCC region detection at boot or module reload. Signed-off-by: Jeremy Linton Acked-by: Viresh Kumar Reviewed-by: Ionela Voinescu Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cppc_cpufreq.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) (limited to 'drivers/cpufreq') diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index 9adb7612993e..432dfb4e8027 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -63,7 +63,15 @@ static struct cppc_workaround_oem_info wa_info[] = { static struct cpufreq_driver cppc_cpufreq_driver; +static enum { + FIE_UNSET = -1, + FIE_ENABLED, + FIE_DISABLED +} fie_disabled = FIE_UNSET; + #ifdef CONFIG_ACPI_CPPC_CPUFREQ_FIE +module_param(fie_disabled, int, 0444); +MODULE_PARM_DESC(fie_disabled, "Disable Frequency Invariance Engine (FIE)"); /* Frequency invariance support */ struct cppc_freq_invariance { @@ -158,7 +166,7 @@ static void cppc_cpufreq_cpu_fie_init(struct cpufreq_policy *policy) struct cppc_freq_invariance *cppc_fi; int cpu, ret; - if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate) + if (fie_disabled) return; for_each_cpu(cpu, policy->cpus) { @@ -199,7 +207,7 @@ static void cppc_cpufreq_cpu_fie_exit(struct cpufreq_policy *policy) struct cppc_freq_invariance *cppc_fi; int cpu; - if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate) + if (fie_disabled) return; /* policy->cpus will be empty here, use related_cpus instead */ @@ -229,7 +237,15 @@ static void __init cppc_freq_invariance_init(void) }; int ret; - if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate) + if (fie_disabled != FIE_ENABLED && fie_disabled != FIE_DISABLED) { + fie_disabled = FIE_ENABLED; + if (cppc_perf_ctrs_in_pcc()) { + pr_info("FIE not enabled on systems with registers in PCC\n"); + fie_disabled = FIE_DISABLED; + } + } + + if (fie_disabled) return; kworker_fie = kthread_create_worker(0, "cppc_fie"); @@ -247,7 +263,7 @@ static void __init cppc_freq_invariance_init(void) static void cppc_freq_invariance_exit(void) { - if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate) + if (fie_disabled) return; kthread_destroy_worker(kworker_fie); @@ -936,6 +952,7 @@ static void cppc_check_hisi_workaround(void) wa_info[i].oem_revision == tbl->oem_revision) { /* Overwrite the get() callback */ cppc_cpufreq_driver.get = hisi_cppc_cpufreq_get_rate; + fie_disabled = FIE_DISABLED; break; } } -- cgit v1.2.3