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.
Compiled and tested with stable-3.18-rc5 on Oracle Sun server X4-2.
--
Ethan Zhao (2):
intel_pstate: skip this driver if Sun server has _PPC method
intel_pstate: add kernel parameter to enable loading on Sun X86
servers.
Documentation/kernel-parameters.txt | 3 +++
drivers/cpufreq/intel_pstate.c | 24 ++++++++++++++++++++++++
2 files changed, 27 insertions(+)
--
1.8.3.1
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 <[email protected]>
v2: only match ORACLE oem id.
---
drivers/cpufreq/intel_pstate.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 27bb6d3..dacc15a 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -943,6 +943,21 @@ 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;
+}
+
struct hw_vendor_info {
u16 valid;
char oem_id[ACPI_OEM_ID_SIZE];
@@ -952,6 +967,7 @@ struct hw_vendor_info {
/* Hardware vendor-specific info that has its own power management modes */
static struct hw_vendor_info vendor_info[] = {
{1, "HP ", "ProLiant"},
+ {1, "ORACLE", ""},
{0, "", ""},
};
@@ -970,11 +986,15 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void)
intel_pstate_no_acpi_pss())
return true;
}
+ if (!strncmp(hdr.oem_id, vendor_info[1].oem_id, ACPI_OEM_ID_SIZE) &&
+ intel_pstate_has_acpi_ppc())
+ return true;
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
To force loading on Oracle Sun X86 servers, provide one kernel command line
parameter
intel_pstate = onora
For those who be aware of the risk doing so.
Signed-off-by: Ethan Zhao <[email protected]>
v2: change the command line parameter naming to specific to Oracle Sun servers.
---
Documentation/kernel-parameters.txt | 3 +++
drivers/cpufreq/intel_pstate.c | 6 +++++-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 479f332..e4b1b81 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1446,6 +1446,9 @@ 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
+ onora
+ Enable loading intel_pstate on Oracle Sun Servers(X86).
+ only for those who be aware of the risk.
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 dacc15a..f28c725 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 load_on_sun;
static int intel_pstate_msrs_not_valid(void)
{
@@ -987,7 +988,8 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void)
return true;
}
if (!strncmp(hdr.oem_id, vendor_info[1].oem_id, ACPI_OEM_ID_SIZE) &&
- intel_pstate_has_acpi_ppc())
+ intel_pstate_has_acpi_ppc() &&
+ !load_on_sun)
return true;
return false;
@@ -1061,6 +1063,8 @@ static int __init intel_pstate_setup(char *str)
if (!strcmp(str, "disable"))
no_load = 1;
+ if (!strcmp(str, "onora"))
+ load_on_sun = 1;
return 0;
}
early_param("intel_pstate", intel_pstate_setup);
--
1.8.3.1