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linux/arch/x86/kernel/acpi/cppc.c
Perry Yuan a51ab63b29 ACPI: CPPC: enable AMD CPPC V2 support for family 17h processors
As there are some AMD processors which only support CPPC V2 firmware and
BIOS implementation, the amd_pstate driver will be failed to load when
system booting with below kernel warning message:

[    0.477523] amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled

To make the amd_pstate driver can be loaded on those TR40 processors, it
needs to match x86_model from 0x30 to 0x7F for family 17H.
With the change, the system can load amd_pstate driver as expected.

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reported-by: Gino Badouri <badouri.g@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218171
Fixes: fbd74d1689 ("ACPI: CPPC: Fix enabling CPPC on AMD systems with shared memory")
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-03-05 13:23:12 +01:00

118 lines
2.6 KiB
C

// 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_supported_by_cpu(void)
{
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
case X86_VENDOR_HYGON:
if (boot_cpu_data.x86 == 0x19 && ((boot_cpu_data.x86_model <= 0x0f) ||
(boot_cpu_data.x86_model >= 0x20 && boot_cpu_data.x86_model <= 0x2f)))
return true;
else if (boot_cpu_data.x86 == 0x17 &&
boot_cpu_data.x86_model >= 0x30 && boot_cpu_data.x86_model <= 0x7f)
return true;
return boot_cpu_has(X86_FEATURE_CPPC);
}
return false;
}
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);
}