By default, the old P-state driver (acpi-freq) is used. Adding "intel_pstate" to the Xen booting param list to enable the use of intel_pstate. However, if intel_pstate is enabled on a machine which does not support the driver (e.g. Nehalem), the old P-state driver will be loaded due to the failure loading of intel_pstate.
Also, adding the intel_pstate booting parameter to xen-command-line.markdown. Signed-off-by: Wei Wang <wei.w.w...@intel.com> --- docs/misc/xen-command-line.markdown | 7 +++++++ xen/arch/x86/acpi/cpufreq/cpufreq.c | 9 ++++++--- xen/arch/x86/acpi/cpufreq/intel_pstate.c | 4 ++++ 3 files changed, 17 insertions(+), 3 deletions(-) changes in v5: 1) move the booting parameter into the intel_pstate_init() function - have it be a local variable; 2) rename "intel_pstate_load" to "load". diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown index a2e427c..2d70137 100644 --- a/docs/misc/xen-command-line.markdown +++ b/docs/misc/xen-command-line.markdown @@ -849,6 +849,13 @@ debug hypervisor only). ### idle\_latency\_factor > `= <integer>` +### intel\_pstate +> `= <boolean>` + +> Default: `false` + +Enable the loading of the intel pstate driver. + ### ioapic\_ack > `= old | new` diff --git a/xen/arch/x86/acpi/cpufreq/cpufreq.c b/xen/arch/x86/acpi/cpufreq/cpufreq.c index 8494fa0..7e517b9 100644 --- a/xen/arch/x86/acpi/cpufreq/cpufreq.c +++ b/xen/arch/x86/acpi/cpufreq/cpufreq.c @@ -40,6 +40,7 @@ #include <asm/processor.h> #include <asm/percpu.h> #include <asm/cpufeature.h> +#include <asm/cpufreq.h> #include <acpi/acpi.h> #include <acpi/cpufreq/cpufreq.h> @@ -647,9 +648,11 @@ static int __init cpufreq_driver_init(void) int ret = 0; if ((cpufreq_controller == FREQCTL_xen) && - (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)) - ret = cpufreq_register_driver(&acpi_cpufreq_driver); - else if ((cpufreq_controller == FREQCTL_xen) && + (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)) { + ret = intel_pstate_init(); + if (ret) + ret = cpufreq_register_driver(&acpi_cpufreq_driver); + } else if ((cpufreq_controller == FREQCTL_xen) && (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)) ret = powernow_register_driver(); diff --git a/xen/arch/x86/acpi/cpufreq/intel_pstate.c b/xen/arch/x86/acpi/cpufreq/intel_pstate.c index 3292bcd..4ebd9c7 100644 --- a/xen/arch/x86/acpi/cpufreq/intel_pstate.c +++ b/xen/arch/x86/acpi/cpufreq/intel_pstate.c @@ -843,7 +843,11 @@ int __init intel_pstate_init(void) int cpu, rc = 0; const struct x86_cpu_id *id; struct cpu_defaults *cpu_info; + static bool_t __read_mostly load; + boolean_param("intel_pstate", load); + if ( !load ) + return -ENODEV; id = x86_match_cpu(intel_pstate_cpu_ids); if ( !id ) -- 1.9.1 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel