2016-10-06 15:59:32

by Eric Ernst

Subject: [PATCH 1/1] thermal/powerclamp: correct cpu support check

Initial logic for checking CPU match resulted in OR of CPU features
rather than the intended AND.

Updated to use boot_cpu_has macro rather than x86_match_cpu.

In addition, MWAIT is the only required CPU feature for idle
injection to work. Drop other feature requirements since they are
only needed for optimal efficiency.

Signed-off-by: Eric Ernst <[email protected]>
---
drivers/thermal/intel_powerclamp.c | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/drivers/thermal/intel_powerclamp.c b/drivers/thermal/intel_powerclamp.c
index 0e4dc0afcfd2..7a223074df3d 100644
--- a/drivers/thermal/intel_powerclamp.c
+++ b/drivers/thermal/intel_powerclamp.c
@@ -669,20 +669,10 @@ static struct thermal_cooling_device_ops powerclamp_cooling_ops = {
.set_cur_state = powerclamp_set_cur_state,
};

-static const struct x86_cpu_id intel_powerclamp_ids[] __initconst = {
- { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_MWAIT },
- { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_ARAT },
- { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_NONSTOP_TSC },
- { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_CONSTANT_TSC},
- {}
-};
-MODULE_DEVICE_TABLE(x86cpu, intel_powerclamp_ids);
-
static int __init powerclamp_probe(void)
{
- if (!x86_match_cpu(intel_powerclamp_ids)) {
- pr_err("Intel powerclamp does not run on family %d model %d\n",
- boot_cpu_data.x86, boot_cpu_data.x86_model);
+ if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
+ pr_err("CPU does not support MWAIT");
return -ENODEV;
}

--
1.9.1

2016-10-07 12:44:51

by Jacob Pan

Subject: Re: [PATCH 1/1] thermal/powerclamp: correct cpu support check

On Thu, 6 Oct 2016 08:56:49 -0700
Eric Ernst <[email protected]> wrote:

> Initial logic for checking CPU match resulted in OR of CPU features
> rather than the intended AND.
>
> Updated to use boot_cpu_has macro rather than x86_match_cpu.
>
> In addition, MWAIT is the only required CPU feature for idle
> injection to work. Drop other feature requirements since they are
> only needed for optimal efficiency.
>

Acked-by: Jacob Pan <[email protected]>

> Signed-off-by: Eric Ernst <[email protected]>
> ---
> drivers/thermal/intel_powerclamp.c | 14 ++------------
> 1 file changed, 2 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/thermal/intel_powerclamp.c
> b/drivers/thermal/intel_powerclamp.c index 0e4dc0afcfd2..7a223074df3d
> 100644 --- a/drivers/thermal/intel_powerclamp.c
> +++ b/drivers/thermal/intel_powerclamp.c
> @@ -669,20 +669,10 @@ static struct thermal_cooling_device_ops
> powerclamp_cooling_ops = { .set_cur_state = powerclamp_set_cur_state,
> };
>
> -static const struct x86_cpu_id intel_powerclamp_ids[] __initconst = {
> - { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY,
> X86_FEATURE_MWAIT },
> - { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY,
> X86_FEATURE_ARAT },
> - { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY,
> X86_FEATURE_NONSTOP_TSC },
> - { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY,
> X86_FEATURE_CONSTANT_TSC},
> - {}
> -};
> -MODULE_DEVICE_TABLE(x86cpu, intel_powerclamp_ids);
> -
> static int __init powerclamp_probe(void)
> {
> - if (!x86_match_cpu(intel_powerclamp_ids)) {
> - pr_err("Intel powerclamp does not run on family %d
> model %d\n",
> - boot_cpu_data.x86,
> boot_cpu_data.x86_model);
> + if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
> + pr_err("CPU does not support MWAIT");
> return -ENODEV;
> }
>

[Jacob Pan]