linux-kernel - [tip: sched/urgent] x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations

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Date:   Wed, 12 May 2021 19:20:06 -0000
From:   "tip-bot2 for Huang Rui" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Jason Bagavatsingham <jason.bagavatsingham@...il.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Huang Rui <ray.huang@....com>, Ingo Molnar <mingo@...nel.org>,
        stable@...r.kernel.org, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: sched/urgent] x86, sched: Fix the AMD CPPC maximum performance
 value on certain AMD Ryzen generations

The following commit has been merged into the sched/urgent branch of tip:

Commit-ID:     337fb3130c29ef5ea3bbcd45e6589b7be6deeb4d
Gitweb:        https://git.kernel.org/tip/337fb3130c29ef5ea3bbcd45e6589b7be6deeb4d
Author:        Huang Rui <ray.huang@....com>
AuthorDate:    Sun, 25 Apr 2021 15:34:51 +08:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Wed, 12 May 2021 21:14:08 +02:00

x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations

Some AMD Ryzen generations has different calculation method on maximum
performance. 255 is not for all ASICs, some specific generations should use 166
as the maximum performance. Otherwise, it will report incorrect frequency value
like below:

  ~ → lscpu | grep MHz
  CPU MHz:                         3400.000
  CPU max MHz:                     7228.3198
  CPU min MHz:                     2200.0000

[ mingo: Tidied up whitespace use. ]

Fixes: 41ea667227ba ("x86, sched: Calculate frequency invariance for AMD systems")
Fixes: 3c55e94c0ade ("cpufreq: ACPI: Extend frequency tables to cover boost frequencies")
Reported-by: Jason Bagavatsingham <jason.bagavatsingham@...il.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Signed-off-by: Huang Rui <ray.huang@....com>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Tested-by: Jason Bagavatsingham <jason.bagavatsingham@...il.com>
Cc: stable@...r.kernel.org
Link: https://lore.kernel.org/r/20210425073451.2557394-1-ray.huang@amd.com
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211791
---
 arch/x86/include/asm/processor.h |  2 ++
 arch/x86/kernel/cpu/amd.c        | 16 ++++++++++++++++
 arch/x86/kernel/smpboot.c        |  2 +-
 drivers/cpufreq/acpi-cpufreq.c   |  6 +++++-
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 154321d..556b2b1 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -787,8 +787,10 @@ DECLARE_PER_CPU(u64, msr_misc_features_shadow);
 
 #ifdef CONFIG_CPU_SUP_AMD
 extern u32 amd_get_nodes_per_socket(void);
+extern u32 amd_get_highest_perf(void);
 #else
 static inline u32 amd_get_nodes_per_socket(void)	{ return 0; }
+static inline u32 amd_get_highest_perf(void)		{ return 0; }
 #endif
 
 static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 2d11384..109d2c7 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -1165,3 +1165,19 @@ void set_dr_addr_mask(unsigned long mask, int dr)
 		break;
 	}
 }
+
+u32 amd_get_highest_perf(void)
+{
+	struct cpuinfo_x86 *c = &boot_cpu_data;
+
+	if (c->x86 == 0x17 && ((c->x86_model >= 0x30 && c->x86_model < 0x40) ||
+			       (c->x86_model >= 0x70 && c->x86_model < 0x80)))
+		return 166;
+
+	if (c->x86 == 0x19 && ((c->x86_model >= 0x20 && c->x86_model < 0x30) ||
+			       (c->x86_model >= 0x40 && c->x86_model < 0x70)))
+		return 166;
+
+	return 225;
+}
+EXPORT_SYMBOL_GPL(amd_get_highest_perf);
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 0ad5214..7770245 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -2043,7 +2043,7 @@ static bool amd_set_max_freq_ratio(void)
 		return false;
 	}
 
-	highest_perf = perf_caps.highest_perf;
+	highest_perf = amd_get_highest_perf();
 	nominal_perf = perf_caps.nominal_perf;
 
 	if (!highest_perf || !nominal_perf) {
diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index d1bbc16..7e74504 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -646,7 +646,11 @@ static u64 get_max_boost_ratio(unsigned int cpu)
 		return 0;
 	}
 
-	highest_perf = perf_caps.highest_perf;
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+		highest_perf = amd_get_highest_perf();
+	else
+		highest_perf = perf_caps.highest_perf;
+
 	nominal_perf = perf_caps.nominal_perf;
 
 	if (!highest_perf || !nominal_perf) {