From: Wei Wang <wei.w.wang@intel.com>
To: xen-devel@lists.xen.org, jbeulich@suse.com
Cc: andrew.cooper3@citrix.com, Wei Wang <wei.w.wang@intel.com>
Subject: [PATCH v3 08/11] x86/intel_pstate: add a booting param to select the driver to load
Date: Thu, 11 Jun 2015 16:28:26 +0800 [thread overview]
Message-ID: <1434011306-17498-1-git-send-email-wei.w.wang@intel.com> (raw)
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.
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
---
xen/arch/x86/acpi/cpufreq/cpufreq.c | 8 +++++---
xen/arch/x86/acpi/cpufreq/intel_pstate.c | 6 ++++++
2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/xen/arch/x86/acpi/cpufreq/cpufreq.c b/xen/arch/x86/acpi/cpufreq/cpufreq.c
index fa3678d..3765fc4 100644
--- a/xen/arch/x86/acpi/cpufreq/cpufreq.c
+++ b/xen/arch/x86/acpi/cpufreq/cpufreq.c
@@ -650,9 +650,11 @@ 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 48bbc30..d1a6056 100644
--- a/xen/arch/x86/acpi/cpufreq/intel_pstate.c
+++ b/xen/arch/x86/acpi/cpufreq/intel_pstate.c
@@ -749,6 +749,9 @@ static struct cpufreq_driver intel_pstate_driver = {
.name = "intel_pstate",
};
+static bool_t __initdata load_intel_pstate;
+boolean_param("intel_pstate", load_intel_pstate);
+
static int intel_pstate_msrs_not_valid(void)
{
if (!pstate_funcs.get_max() ||
@@ -785,6 +788,9 @@ int __init intel_pstate_init(void)
const struct x86_cpu_id *id;
struct cpu_defaults *cpu_info;
+ if (!load_intel_pstate)
+ return -ENODEV;
+
id = x86_match_cpu(intel_pstate_cpu_ids);
if (!id)
return -ENODEV;
--
1.9.1
next reply other threads:[~2015-06-11 8:28 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-11 8:28 Wei Wang [this message]
2015-06-18 15:07 ` [PATCH v3 08/11] x86/intel_pstate: add a booting param to select the driver to load Jan Beulich
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