From bb20421c05fc0a0fd70a3f8af076319f7dec4cf1 Mon Sep 17 00:00:00 2001 From: Perry Yuan Date: Mon, 9 Jun 2025 15:05:12 -0500 Subject: [PATCH] platform/x86: hfi: Add online and offline callback support MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit There are some firmware parameters that need to be configured when a CPU core is brought online or offline. When a CPU is online, it will initialize the workload classification parameters to CPU firmware which will trigger the workload class ID updating function. Once the CPU is going offline, it will need to disable the workload classification function and clear the history. Signed-off-by: Perry Yuan Co-developed-by: Mario Limonciello Signed-off-by: Mario Limonciello Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Gautham R. Shenoy Acked-by: Ilpo Järvinen Link: https://lore.kernel.org/20250609200518.3616080-8-superm1@kernel.org --- drivers/platform/x86/amd/hfi/hfi.c | 88 ++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) diff --git a/drivers/platform/x86/amd/hfi/hfi.c b/drivers/platform/x86/amd/hfi/hfi.c index b10bd96c59205..28ef7212d3393 100644 --- a/drivers/platform/x86/amd/hfi/hfi.c +++ b/drivers/platform/x86/amd/hfi/hfi.c @@ -92,6 +92,7 @@ struct amd_hfi_classes { * struct amd_hfi_cpuinfo - HFI workload class info per CPU * @cpu: CPU index * @apic_id: APIC id of the current CPU + * @cpus: mask of CPUs associated with amd_hfi_cpuinfo * @class_index: workload class ID index * @nr_class: max number of workload class supported * @ipcc_scores: ipcc scores for each class @@ -102,6 +103,7 @@ struct amd_hfi_classes { struct amd_hfi_cpuinfo { int cpu; u32 apic_id; + cpumask_var_t cpus; s16 class_index; u8 nr_class; int *ipcc_scores; @@ -110,6 +112,8 @@ struct amd_hfi_cpuinfo { static DEFINE_PER_CPU(struct amd_hfi_cpuinfo, amd_hfi_cpuinfo) = {.class_index = -1}; +static DEFINE_MUTEX(hfi_cpuinfo_lock); + static int find_cpu_index_by_apicid(unsigned int target_apicid) { int cpu_index; @@ -237,6 +241,81 @@ static int amd_set_hfi_ipcc_score(struct amd_hfi_cpuinfo *hfi_cpuinfo, int cpu) return 0; } +static int amd_hfi_set_state(unsigned int cpu, bool state) +{ + int ret; + + ret = wrmsrq_on_cpu(cpu, MSR_AMD_WORKLOAD_CLASS_CONFIG, state ? 1 : 0); + if (ret) + return ret; + + return wrmsrq_on_cpu(cpu, MSR_AMD_WORKLOAD_HRST, 0x1); +} + +/** + * amd_hfi_online() - Enable workload classification on @cpu + * @cpu: CPU in which the workload classification will be enabled + * + * Return: 0 on success, negative error code on failure. + */ +static int amd_hfi_online(unsigned int cpu) +{ + struct amd_hfi_cpuinfo *hfi_info = per_cpu_ptr(&amd_hfi_cpuinfo, cpu); + struct amd_hfi_classes *hfi_classes; + int ret; + + if (WARN_ON_ONCE(!hfi_info)) + return -EINVAL; + + /* + * Check if @cpu as an associated, initialized and ranking data must + * be filled. + */ + hfi_classes = hfi_info->amd_hfi_classes; + if (!hfi_classes) + return -EINVAL; + + guard(mutex)(&hfi_cpuinfo_lock); + + if (!zalloc_cpumask_var(&hfi_info->cpus, GFP_KERNEL)) + return -ENOMEM; + + cpumask_set_cpu(cpu, hfi_info->cpus); + + ret = amd_hfi_set_state(cpu, true); + if (ret) + pr_err("WCT enable failed for CPU %u\n", cpu); + + return ret; +} + +/** + * amd_hfi_offline() - Disable workload classification on @cpu + * @cpu: CPU in which the workload classification will be disabled + * + * Remove @cpu from those covered by its HFI instance. + * + * Return: 0 on success, negative error code on failure + */ +static int amd_hfi_offline(unsigned int cpu) +{ + struct amd_hfi_cpuinfo *hfi_info = &per_cpu(amd_hfi_cpuinfo, cpu); + int ret; + + if (WARN_ON_ONCE(!hfi_info)) + return -EINVAL; + + guard(mutex)(&hfi_cpuinfo_lock); + + ret = amd_hfi_set_state(cpu, false); + if (ret) + pr_err("WCT disable failed for CPU %u\n", cpu); + + free_cpumask_var(hfi_info->cpus); + + return ret; +} + static int update_hfi_ipcc_scores(void) { int cpu; @@ -339,6 +418,15 @@ static int amd_hfi_probe(struct platform_device *pdev) if (ret) return ret; + /* + * Tasks will already be running at the time this happens. This is + * OK because rankings will be adjusted by the callbacks. + */ + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/amd_hfi:online", + amd_hfi_online, amd_hfi_offline); + if (ret < 0) + return ret; + return 0; } -- 2.47.2