From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- arch/arm64/kernel/topology.c | 348 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 348 insertions(+) create mode 100644 arch/arm64/kernel/topology.c (limited to 'arch/arm64/kernel/topology.c') diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c new file mode 100644 index 000000000..817d788cd --- /dev/null +++ b/arch/arm64/kernel/topology.c @@ -0,0 +1,348 @@ +/* + * arch/arm64/kernel/topology.c + * + * Copyright (C) 2011,2013,2014 Linaro Limited. + * + * Based on the arm32 version written by Vincent Guittot in turn based on + * arch/sh/kernel/topology.c + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#ifdef CONFIG_ACPI +static bool __init acpi_cpu_is_threaded(int cpu) +{ + int is_threaded = acpi_pptt_cpu_is_thread(cpu); + + /* + * if the PPTT doesn't have thread information, assume a homogeneous + * machine and return the current CPU's thread state. + */ + if (is_threaded < 0) + is_threaded = read_cpuid_mpidr() & MPIDR_MT_BITMASK; + + return !!is_threaded; +} + +/* + * Propagate the topology information of the processor_topology_node tree to the + * cpu_topology array. + */ +int __init parse_acpi_topology(void) +{ + int cpu, topology_id; + + if (acpi_disabled) + return 0; + + for_each_possible_cpu(cpu) { + topology_id = find_acpi_cpu_topology(cpu, 0); + if (topology_id < 0) + return topology_id; + + if (acpi_cpu_is_threaded(cpu)) { + cpu_topology[cpu].thread_id = topology_id; + topology_id = find_acpi_cpu_topology(cpu, 1); + cpu_topology[cpu].core_id = topology_id; + } else { + cpu_topology[cpu].thread_id = -1; + cpu_topology[cpu].core_id = topology_id; + } + topology_id = find_acpi_cpu_topology_cluster(cpu); + cpu_topology[cpu].cluster_id = topology_id; + topology_id = find_acpi_cpu_topology_package(cpu); + cpu_topology[cpu].package_id = topology_id; + } + + return 0; +} +#endif + +#ifdef CONFIG_ARM64_AMU_EXTN +#define read_corecnt() read_sysreg_s(SYS_AMEVCNTR0_CORE_EL0) +#define read_constcnt() read_sysreg_s(SYS_AMEVCNTR0_CONST_EL0) +#else +#define read_corecnt() (0UL) +#define read_constcnt() (0UL) +#endif + +#undef pr_fmt +#define pr_fmt(fmt) "AMU: " fmt + +static DEFINE_PER_CPU_READ_MOSTLY(unsigned long, arch_max_freq_scale); +static DEFINE_PER_CPU(u64, arch_const_cycles_prev); +static DEFINE_PER_CPU(u64, arch_core_cycles_prev); +static cpumask_var_t amu_fie_cpus; + +void update_freq_counters_refs(void) +{ + this_cpu_write(arch_core_cycles_prev, read_corecnt()); + this_cpu_write(arch_const_cycles_prev, read_constcnt()); +} + +static inline bool freq_counters_valid(int cpu) +{ + if ((cpu >= nr_cpu_ids) || !cpumask_test_cpu(cpu, cpu_present_mask)) + return false; + + if (!cpu_has_amu_feat(cpu)) { + pr_debug("CPU%d: counters are not supported.\n", cpu); + return false; + } + + if (unlikely(!per_cpu(arch_const_cycles_prev, cpu) || + !per_cpu(arch_core_cycles_prev, cpu))) { + pr_debug("CPU%d: cycle counters are not enabled.\n", cpu); + return false; + } + + return true; +} + +static int freq_inv_set_max_ratio(int cpu, u64 max_rate, u64 ref_rate) +{ + u64 ratio; + + if (unlikely(!max_rate || !ref_rate)) { + pr_debug("CPU%d: invalid maximum or reference frequency.\n", + cpu); + return -EINVAL; + } + + /* + * Pre-compute the fixed ratio between the frequency of the constant + * reference counter and the maximum frequency of the CPU. + * + * ref_rate + * arch_max_freq_scale = ---------- * SCHED_CAPACITY_SCALE² + * max_rate + * + * We use a factor of 2 * SCHED_CAPACITY_SHIFT -> SCHED_CAPACITY_SCALE² + * in order to ensure a good resolution for arch_max_freq_scale for + * very low reference frequencies (down to the KHz range which should + * be unlikely). + */ + ratio = ref_rate << (2 * SCHED_CAPACITY_SHIFT); + ratio = div64_u64(ratio, max_rate); + if (!ratio) { + WARN_ONCE(1, "Reference frequency too low.\n"); + return -EINVAL; + } + + per_cpu(arch_max_freq_scale, cpu) = (unsigned long)ratio; + + return 0; +} + +static void amu_scale_freq_tick(void) +{ + u64 prev_core_cnt, prev_const_cnt; + u64 core_cnt, const_cnt, scale; + + prev_const_cnt = this_cpu_read(arch_const_cycles_prev); + prev_core_cnt = this_cpu_read(arch_core_cycles_prev); + + update_freq_counters_refs(); + + const_cnt = this_cpu_read(arch_const_cycles_prev); + core_cnt = this_cpu_read(arch_core_cycles_prev); + + if (unlikely(core_cnt <= prev_core_cnt || + const_cnt <= prev_const_cnt)) + return; + + /* + * /\core arch_max_freq_scale + * scale = ------- * -------------------- + * /\const SCHED_CAPACITY_SCALE + * + * See validate_cpu_freq_invariance_counters() for details on + * arch_max_freq_scale and the use of SCHED_CAPACITY_SHIFT. + */ + scale = core_cnt - prev_core_cnt; + scale *= this_cpu_read(arch_max_freq_scale); + scale = div64_u64(scale >> SCHED_CAPACITY_SHIFT, + const_cnt - prev_const_cnt); + + scale = min_t(unsigned long, scale, SCHED_CAPACITY_SCALE); + this_cpu_write(arch_freq_scale, (unsigned long)scale); +} + +static struct scale_freq_data amu_sfd = { + .source = SCALE_FREQ_SOURCE_ARCH, + .set_freq_scale = amu_scale_freq_tick, +}; + +static void amu_fie_setup(const struct cpumask *cpus) +{ + int cpu; + + /* We are already set since the last insmod of cpufreq driver */ + if (unlikely(cpumask_subset(cpus, amu_fie_cpus))) + return; + + for_each_cpu(cpu, cpus) { + if (!freq_counters_valid(cpu) || + freq_inv_set_max_ratio(cpu, + cpufreq_get_hw_max_freq(cpu) * 1000ULL, + arch_timer_get_rate())) + return; + } + + cpumask_or(amu_fie_cpus, amu_fie_cpus, cpus); + + topology_set_scale_freq_source(&amu_sfd, amu_fie_cpus); + + pr_debug("CPUs[%*pbl]: counters will be used for FIE.", + cpumask_pr_args(cpus)); +} + +static int init_amu_fie_callback(struct notifier_block *nb, unsigned long val, + void *data) +{ + struct cpufreq_policy *policy = data; + + if (val == CPUFREQ_CREATE_POLICY) + amu_fie_setup(policy->related_cpus); + + /* + * We don't need to handle CPUFREQ_REMOVE_POLICY event as the AMU + * counters don't have any dependency on cpufreq driver once we have + * initialized AMU support and enabled invariance. The AMU counters will + * keep on working just fine in the absence of the cpufreq driver, and + * for the CPUs for which there are no counters available, the last set + * value of arch_freq_scale will remain valid as that is the frequency + * those CPUs are running at. + */ + + return 0; +} + +static struct notifier_block init_amu_fie_notifier = { + .notifier_call = init_amu_fie_callback, +}; + +static int __init init_amu_fie(void) +{ + int ret; + + if (!zalloc_cpumask_var(&amu_fie_cpus, GFP_KERNEL)) + return -ENOMEM; + + ret = cpufreq_register_notifier(&init_amu_fie_notifier, + CPUFREQ_POLICY_NOTIFIER); + if (ret) + free_cpumask_var(amu_fie_cpus); + + return ret; +} +core_initcall(init_amu_fie); + +#ifdef CONFIG_ACPI_CPPC_LIB +#include + +static void cpu_read_corecnt(void *val) +{ + /* + * A value of 0 can be returned if the current CPU does not support AMUs + * or if the counter is disabled for this CPU. A return value of 0 at + * counter read is properly handled as an error case by the users of the + * counter. + */ + *(u64 *)val = read_corecnt(); +} + +static void cpu_read_constcnt(void *val) +{ + /* + * Return 0 if the current CPU is affected by erratum 2457168. A value + * of 0 is also returned if the current CPU does not support AMUs or if + * the counter is disabled. A return value of 0 at counter read is + * properly handled as an error case by the users of the counter. + */ + *(u64 *)val = this_cpu_has_cap(ARM64_WORKAROUND_2457168) ? + 0UL : read_constcnt(); +} + +static inline +int counters_read_on_cpu(int cpu, smp_call_func_t func, u64 *val) +{ + /* + * Abort call on counterless CPU or when interrupts are + * disabled - can lead to deadlock in smp sync call. + */ + if (!cpu_has_amu_feat(cpu)) + return -EOPNOTSUPP; + + if (WARN_ON_ONCE(irqs_disabled())) + return -EPERM; + + smp_call_function_single(cpu, func, val, 1); + + return 0; +} + +/* + * Refer to drivers/acpi/cppc_acpi.c for the description of the functions + * below. + */ +bool cpc_ffh_supported(void) +{ + int cpu = get_cpu_with_amu_feat(); + + /* + * FFH is considered supported if there is at least one present CPU that + * supports AMUs. Using FFH to read core and reference counters for CPUs + * that do not support AMUs, have counters disabled or that are affected + * by errata, will result in a return value of 0. + * + * This is done to allow any enabled and valid counters to be read + * through FFH, knowing that potentially returning 0 as counter value is + * properly handled by the users of these counters. + */ + if ((cpu >= nr_cpu_ids) || !cpumask_test_cpu(cpu, cpu_present_mask)) + return false; + + return true; +} + +int cpc_read_ffh(int cpu, struct cpc_reg *reg, u64 *val) +{ + int ret = -EOPNOTSUPP; + + switch ((u64)reg->address) { + case 0x0: + ret = counters_read_on_cpu(cpu, cpu_read_corecnt, val); + break; + case 0x1: + ret = counters_read_on_cpu(cpu, cpu_read_constcnt, val); + break; + } + + if (!ret) { + *val &= GENMASK_ULL(reg->bit_offset + reg->bit_width - 1, + reg->bit_offset); + *val >>= reg->bit_offset; + } + + return ret; +} + +int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val) +{ + return -EOPNOTSUPP; +} +#endif /* CONFIG_ACPI_CPPC_LIB */ -- cgit v1.2.3