This code is convoluted and because it can be invoked post init via the ACPI/CPPC code, all of the initialization functionality is built in instead of being part of init text and init data. As a first step create separate calls for the boot and the application processors. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/20220415161206.536733494@linutronix.de
104 lines
2.1 KiB
C
104 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* cppc.c: CPPC Interface for x86
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* Copyright (c) 2016, Intel Corporation.
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*/
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#include <acpi/cppc_acpi.h>
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#include <asm/msr.h>
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#include <asm/processor.h>
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#include <asm/topology.h>
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/* Refer to drivers/acpi/cppc_acpi.c for the description of functions */
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bool cpc_ffh_supported(void)
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{
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return true;
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}
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int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val)
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{
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int err;
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err = rdmsrl_safe_on_cpu(cpunum, reg->address, val);
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if (!err) {
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u64 mask = GENMASK_ULL(reg->bit_offset + reg->bit_width - 1,
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reg->bit_offset);
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*val &= mask;
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*val >>= reg->bit_offset;
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}
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return err;
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}
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int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val)
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{
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u64 rd_val;
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int err;
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err = rdmsrl_safe_on_cpu(cpunum, reg->address, &rd_val);
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if (!err) {
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u64 mask = GENMASK_ULL(reg->bit_offset + reg->bit_width - 1,
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reg->bit_offset);
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val <<= reg->bit_offset;
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val &= mask;
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rd_val &= ~mask;
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rd_val |= val;
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err = wrmsrl_safe_on_cpu(cpunum, reg->address, rd_val);
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}
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return err;
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}
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bool amd_set_max_freq_ratio(u64 *ratio)
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{
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struct cppc_perf_caps perf_caps;
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u64 highest_perf, nominal_perf;
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u64 perf_ratio;
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int rc;
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if (!ratio)
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return false;
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rc = cppc_get_perf_caps(0, &perf_caps);
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if (rc) {
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pr_debug("Could not retrieve perf counters (%d)\n", rc);
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return false;
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}
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highest_perf = amd_get_highest_perf();
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nominal_perf = perf_caps.nominal_perf;
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if (!highest_perf || !nominal_perf) {
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pr_debug("Could not retrieve highest or nominal performance\n");
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return false;
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}
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perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf);
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/* midpoint between max_boost and max_P */
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perf_ratio = (perf_ratio + SCHED_CAPACITY_SCALE) >> 1;
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if (!perf_ratio) {
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pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n");
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return false;
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}
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*ratio = perf_ratio;
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arch_set_max_freq_ratio(false);
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return true;
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}
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static DEFINE_MUTEX(freq_invariance_lock);
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void init_freq_invariance_cppc(void)
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{
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static bool secondary;
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mutex_lock(&freq_invariance_lock);
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if (!secondary)
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bp_init_freq_invariance(true);
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secondary = true;
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mutex_unlock(&freq_invariance_lock);
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}
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