[PATCH 0/2 V4] intel_pstate: skip this driver if hit Sun X86 servers

[PATCH 0/2 V4] intel_pstate: skip this driver if hit Sun X86 servers

[Ethan Zhao]

Oracle Sun servers(X86) have power capping features that work via ACPI _PPC method,
patch No.1 is used to skip this driver if Oracle Sun server and _PPC detected.
Patch No.2 introduces a kernel command line parameter for those who would like
to enable intel_pstate on Sun X86 servers and be aware of the risk of no power
capping capability working and try to get better performance.

Compiled and tested with stable-3.18-rc5 on Oracle Sun server X4-2 series.

Thanks test and review by Linda Knippers <linda.knippers@hp.com>
and the suggestion,review from Dirk Brandewie <dirk.j.brandewie@intel.com>.
--
v2: fix break HP Proliant issue.
v3: expand the hardware vendor list.
v4: refine code and doc

Ethan Zhao (2):
  intel_pstate: skip this driver if Sun server has _PPC method
  intel_pstate: add kernel parameter to force loading on Sun X86
    servers.

 Documentation/kernel-parameters.txt |  5 ++++
 drivers/cpufreq/intel_pstate.c      | 49 ++++++++++++++++++++++++++++++++++---
 2 files changed, 50 insertions(+), 4 deletions(-)

-- 
1.8.3.1

[PATCH 1/2 V4] intel_pstate: skip this driver if Sun server has _PPC method

[Ethan Zhao]

Oracle Sun X86 servers have dynamic power capping capability that works via
ACPI _PPC method etc, so skip loading this driver if Sun server has ACPI _PPC
enabled.

Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Tested-by: Linda Knippers <linda.knippers@hp.com>
---
  v2: fix break HP Proliant issue.
  v3: expand the hardware vendor list.
  v4: refine code.

 drivers/cpufreq/intel_pstate.c | 45 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 41 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 27bb6d3..1bb62ca 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -943,15 +943,46 @@ static bool intel_pstate_no_acpi_pss(void)
 	return true;
 }
 
+static bool intel_pstate_has_acpi_ppc(void)
+{
+	int i;
+
+	for_each_possible_cpu(i) {
+		struct acpi_processor *pr = per_cpu(processors, i);
+
+		if (!pr)
+			continue;
+		if (acpi_has_method(pr->handle, "_PPC"))
+			return true;
+	}
+	return false;
+}
+
+enum {
+	PSS,
+	PCC,
+};
+
 struct hw_vendor_info {
 	u16  valid;
 	char oem_id[ACPI_OEM_ID_SIZE];
 	char oem_table_id[ACPI_OEM_TABLE_ID_SIZE];
+	int  oem_pwr_table;
 };
 
 /* Hardware vendor-specific info that has its own power management modes */
 static struct hw_vendor_info vendor_info[] = {
-	{1, "HP    ", "ProLiant"},
+	{1, "HP    ", "ProLiant", PSS},
+	{1, "ORACLE", "X4-2    ", PCC},
+	{1, "ORACLE", "X4-2L   ", PCC},
+	{1, "ORACLE", "X4-2B   ", PCC},
+	{1, "ORACLE", "X3-2    ", PCC},
+	{1, "ORACLE", "X3-2L   ", PCC},
+	{1, "ORACLE", "X3-2B   ", PCC},
+	{1, "ORACLE", "X4470M2 ", PCC},
+	{1, "ORACLE", "X4270M3 ", PCC},
+	{1, "ORACLE", "X4270M2 ", PCC},
+	{1, "ORACLE", "X4170M2 ", PCC},
 	{0, "", ""},
 };
 
@@ -966,15 +997,21 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void)
 
 	for (v_info = vendor_info; v_info->valid; v_info++) {
 		if (!strncmp(hdr.oem_id, v_info->oem_id, ACPI_OEM_ID_SIZE) &&
-		    !strncmp(hdr.oem_table_id, v_info->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
-		    intel_pstate_no_acpi_pss())
-			return true;
+			!strncmp(hdr.oem_table_id, v_info->oem_table_id,
+						ACPI_OEM_TABLE_ID_SIZE))
+			switch (v_info->oem_pwr_table) {
+			case PSS:
+				return intel_pstate_no_acpi_pss();
+			case PCC:
+				return intel_pstate_has_acpi_ppc();
+			}
 	}
 
 	return false;
 }
 #else /* CONFIG_ACPI not enabled */
 static inline bool intel_pstate_platform_pwr_mgmt_exists(void) { return false; }
+static inline bool intel_pstate_has_acpi_ppc(void) { return false; }
 #endif /* CONFIG_ACPI */
 
 static int __init intel_pstate_init(void)
-- 
1.8.3.1

[PATCH 2/2 V5] intel_pstate: add kernel parameter to force loading on Sun X86 servers.

[Ethan Zhao]

To force loading on Oracle Sun X86 servers, provide one kernel command line
parameter

  intel_pstate = ora_force

For those who be aware of the risk of no power capping capabily working and
try to get better performance with this driver.

Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
---
 v2: change to hardware vendor specific naming parameter.
 v4: refine code and doc.
 v5: fix a type in doc.

 Documentation/kernel-parameters.txt | 5 +++++
 drivers/cpufreq/intel_pstate.c      | 6 +++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 479f332..7d0983e 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1446,6 +1446,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 		       disable
 		         Do not enable intel_pstate as the default
 		         scaling driver for the supported processors
+		       ora_force
+			 Force loading intel_pstate on Oracle Sun Servers(X86).
+			 only for those who be aware of the risk of no power capping
+			 capability working and try to get better performance with this
+			 driver.
 
 	intremap=	[X86-64, Intel-IOMMU]
 			on	enable Interrupt Remapping (default)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 1bb62ca..2654e13 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -866,6 +866,7 @@ static struct cpufreq_driver intel_pstate_driver = {
 };
 
 static int __initdata no_load;
+static unsigned int  ora_force;
 
 static int intel_pstate_msrs_not_valid(void)
 {
@@ -1003,7 +1004,8 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void)
 			case PSS:
 				return intel_pstate_no_acpi_pss();
 			case PCC:
-				return intel_pstate_has_acpi_ppc();
+				return intel_pstate_has_acpi_ppc() &&
+					(!ora_force);
 			}
 	}
 
@@ -1078,6 +1080,8 @@ static int __init intel_pstate_setup(char *str)
 
 	if (!strcmp(str, "disable"))
 		no_load = 1;
+	if (!strcmp(str, "ora_force"))
+		ora_force = 1;
 	return 0;
 }
 early_param("intel_pstate", intel_pstate_setup);
-- 
1.8.3.1

[PATCH 2/2 V5] intel_pstate: add kernel parameter to force loading on Sun X86 servers.

[Ethan Zhao]

To force loading on Oracle Sun X86 servers, provide one kernel command line
parameter

  intel_pstate = ora_force

For those who be aware of the risk of no power capping capabily working and
try to get better performance with this driver.

Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
---
 v2: change to hardware vendor specific naming parameter.
 v4: refine code and doc.
 v5: fix a type in doc.

 Documentation/kernel-parameters.txt | 5 +++++
 drivers/cpufreq/intel_pstate.c      | 6 +++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 479f332..7d0983e 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1446,6 +1446,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 		       disable
 		         Do not enable intel_pstate as the default
 		         scaling driver for the supported processors
+		       ora_force
+			 Force loading intel_pstate on Oracle Sun Servers(X86).
+			 only for those who be aware of the risk of no power capping
+			 capability working and try to get better performance with this
+			 driver.
 
 	intremap=	[X86-64, Intel-IOMMU]
 			on	enable Interrupt Remapping (default)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 1bb62ca..2654e13 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -866,6 +866,7 @@ static struct cpufreq_driver intel_pstate_driver = {
 };
 
 static int __initdata no_load;
+static unsigned int  ora_force;
 
 static int intel_pstate_msrs_not_valid(void)
 {
@@ -1003,7 +1004,8 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void)
 			case PSS:
 				return intel_pstate_no_acpi_pss();
 			case PCC:
-				return intel_pstate_has_acpi_ppc();
+				return intel_pstate_has_acpi_ppc() &&
+					(!ora_force);
 			}
 	}
 
@@ -1078,6 +1080,8 @@ static int __init intel_pstate_setup(char *str)
 
 	if (!strcmp(str, "disable"))
 		no_load = 1;
+	if (!strcmp(str, "ora_force"))
+		ora_force = 1;
 	return 0;
 }
 early_param("intel_pstate", intel_pstate_setup);
-- 
1.8.3.1