* [PATCH v4 09/11] x86/intel_pstate: add a booting param to select the driver to load
@ 2015-06-25 11:17 Wei Wang
2015-07-24 13:58 ` Jan Beulich
0 siblings, 1 reply; 2+ messages in thread
From: Wei Wang @ 2015-06-25 11:17 UTC (permalink / raw)
To: jbeulich, andrew.cooper3, xen-devel; +Cc: Wei Wang
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.
v4 changes:
1) moved the definition of "load_intel_pstate" right ahead of
intel_pstate_init();
2) merged the previous patch,"adding the booting param to
xen.command-line.markdown", into this one.
Signed-off-by: Wei Wang <wei.w.wang@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 | 6 ++++++
3 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown
index 4889e27..249bf65 100644
--- a/docs/misc/xen-command-line.markdown
+++ b/docs/misc/xen-command-line.markdown
@@ -830,6 +830,13 @@ 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 643c405..e737437 100644
--- a/xen/arch/x86/acpi/cpufreq/cpufreq.c
+++ b/xen/arch/x86/acpi/cpufreq/cpufreq.c
@@ -41,6 +41,7 @@
#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>
@@ -648,9 +649,11 @@ 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 19c74cc..5e03625 100644
--- a/xen/arch/x86/acpi/cpufreq/intel_pstate.c
+++ b/xen/arch/x86/acpi/cpufreq/intel_pstate.c
@@ -831,12 +831,18 @@ static void __init copy_cpu_funcs(struct pstate_funcs *funcs)
pstate_funcs.get_vid = funcs->get_vid;
}
+static bool_t __initdata load_intel_pstate;
+boolean_param("intel_pstate", load_intel_pstate);
+
int __init intel_pstate_init(void)
{
int cpu, rc = 0;
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
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v4 09/11] x86/intel_pstate: add a booting param to select the driver to load
2015-06-25 11:17 [PATCH v4 09/11] x86/intel_pstate: add a booting param to select the driver to load Wei Wang
@ 2015-07-24 13:58 ` Jan Beulich
0 siblings, 0 replies; 2+ messages in thread
From: Jan Beulich @ 2015-07-24 13:58 UTC (permalink / raw)
To: Wei Wang; +Cc: andrew.cooper3, xen-devel
>>> On 25.06.15 at 13:17, <wei.w.wang@intel.com> wrote:
> 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.
>
> v4 changes:
> 1) moved the definition of "load_intel_pstate" right ahead of
> intel_pstate_init();
Didn't I ask for it to be moved _inside_ the function?
> --- a/xen/arch/x86/acpi/cpufreq/intel_pstate.c
> +++ b/xen/arch/x86/acpi/cpufreq/intel_pstate.c
> @@ -831,12 +831,18 @@ static void __init copy_cpu_funcs(struct pstate_funcs *funcs)
> pstate_funcs.get_vid = funcs->get_vid;
> }
>
> +static bool_t __initdata load_intel_pstate;
> +boolean_param("intel_pstate", load_intel_pstate);
> +
> int __init intel_pstate_init(void)
> {
> int cpu, rc = 0;
> const struct x86_cpu_id *id;
> struct cpu_defaults *cpu_info;
>
> + if (!load_intel_pstate)
> + return -ENODEV;
> +
With the variable then perhaps simply be named "load"?
Jan
^ permalink raw reply [flat|nested] 2+ messages in thread
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