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// SPDX-License-Identifier: GPL-2.0-only
/*
* cppc.c: CPPC Interface for x86
* Copyright (c) 2016, Intel Corporation.
*/
#include <acpi/cppc_acpi.h>
#include <asm/msr.h>
#include <asm/processor.h>
#include <asm/topology.h>
/* Refer to drivers/acpi/cppc_acpi.c for the description of functions */
bool cpc_ffh_supported(void)
{
return true;
}
int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val)
{
int err;
err = rdmsrl_safe_on_cpu(cpunum, reg->address, val);
if (!err) {
u64 mask = GENMASK_ULL(reg->bit_offset + reg->bit_width - 1,
reg->bit_offset);
*val &= mask;
*val >>= reg->bit_offset;
}
return err;
}
int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val)
{
u64 rd_val;
int err;
err = rdmsrl_safe_on_cpu(cpunum, reg->address, &rd_val);
if (!err) {
u64 mask = GENMASK_ULL(reg->bit_offset + reg->bit_width - 1,
reg->bit_offset);
val <<= reg->bit_offset;
val &= mask;
rd_val &= ~mask;
rd_val |= val;
err = wrmsrl_safe_on_cpu(cpunum, reg->address, rd_val);
}
return err;
}
static void amd_set_max_freq_ratio(void)
{
struct cppc_perf_caps perf_caps;
u64 highest_perf, nominal_perf;
u64 perf_ratio;
int rc;
rc = cppc_get_perf_caps(0, &perf_caps);
if (rc) {
pr_debug("Could not retrieve perf counters (%d)\n", rc);
return;
}
highest_perf = amd_get_highest_perf();
nominal_perf = perf_caps.nominal_perf;
if (!highest_perf || !nominal_perf) {
pr_debug("Could not retrieve highest or nominal performance\n");
return;
}
perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf);
/* midpoint between max_boost and max_P */
perf_ratio = (perf_ratio + SCHED_CAPACITY_SCALE) >> 1;
if (!perf_ratio) {
pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n");
return;
}
freq_invariance_set_perf_ratio(perf_ratio, false);
}
static DEFINE_MUTEX(freq_invariance_lock);
void init_freq_invariance_cppc(void)
{
static bool init_done;
if (!cpu_feature_enabled(X86_FEATURE_APERFMPERF))
return;
if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
return;
mutex_lock(&freq_invariance_lock);
if (!init_done)
amd_set_max_freq_ratio();
init_done = true;
mutex_unlock(&freq_invariance_lock);
}
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