From: Jan Beulich <jbeulich@suse.com>
To: Jason Andryuk <jandryuk@gmail.com>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
"Roger Pau Monné" <roger.pau@citrix.com>, "Wei Liu" <wl@xen.org>,
"George Dunlap" <george.dunlap@citrix.com>,
"Ian Jackson" <iwj@xenproject.org>,
"Julien Grall" <julien@xen.org>,
"Stefano Stabellini" <sstabellini@kernel.org>,
xen-devel@lists.xenproject.org
Subject: Re: [PATCH 09/13] xen: Add SET_CPUFREQ_HWP xen_sysctl_pm_op
Date: Thu, 27 May 2021 10:33:45 +0200 [thread overview]
Message-ID: <fe5d6d76-83a8-aabd-0148-949726a45ad0@suse.com> (raw)
In-Reply-To: <20210503192810.36084-10-jandryuk@gmail.com>
On 03.05.2021 21:28, Jason Andryuk wrote:
> --- a/xen/arch/x86/acpi/cpufreq/hwp.c
> +++ b/xen/arch/x86/acpi/cpufreq/hwp.c
> @@ -547,6 +547,120 @@ int get_hwp_para(struct cpufreq_policy *policy, struct xen_hwp_para *hwp_para)
> return 0;
> }
>
> +int set_hwp_para(struct cpufreq_policy *policy,
> + struct xen_set_hwp_para *set_hwp)
> +{
> + unsigned int cpu = policy->cpu;
> + struct hwp_drv_data *data = hwp_drv_data[cpu];
> +
> + if ( data == NULL )
> + return -EINVAL;
> +
> + /* Validate all parameters first */
> + if ( set_hwp->set_params & ~XEN_SYSCTL_HWP_SET_PARAM_MASK )
> + {
> + hwp_err("Invalid bits in hwp set_params %u\n",
> + set_hwp->set_params);
> +
> + return -EINVAL;
> + }
> +
> + if ( set_hwp->activity_window & ~XEN_SYSCTL_HWP_ACT_WINDOW_MASK )
> + {
> + hwp_err("Invalid bits in activity window %u\n",
> + set_hwp->activity_window);
> +
> + return -EINVAL;
> + }
> +
> + if ( !feature_hwp_energy_perf &&
> + set_hwp->set_params & XEN_SYSCTL_HWP_SET_ENERGY_PERF &&
Please add parentheses around the operands of & here and ...
> + set_hwp->energy_perf > 0xf )
> + {
> + hwp_err("energy_perf %u out of range for IA32_ENERGY_PERF_BIAS\n",
> + set_hwp->energy_perf);
> +
> + return -EINVAL;
> + }
> +
> + if ( set_hwp->set_params & XEN_SYSCTL_HWP_SET_DESIRED &&
... here.
> + set_hwp->desired != 0 &&
> + ( set_hwp->desired < data->hw_lowest ||
> + set_hwp->desired > data->hw_highest ) )
Excess blanks inside the inner pair of parentheses.
> + {
> + hwp_err("hwp desired %u is out of range (%u ... %u)\n",
> + set_hwp->desired, data->hw_lowest, data->hw_highest);
> +
> + return -EINVAL;
> + }
None of these -EINVAL should be accompanied by a hwp_err, imo.
> + /*
> + * minimum & maximum are not validated as hardware doesn't seem to care
> + * and the SDM says CPUs will clip internally.
> + */
> +
> + /* Apply presets */
> + switch ( set_hwp->set_params & XEN_SYSCTL_HWP_SET_PRESET_MASK )
> + {
> + case XEN_SYSCTL_HWP_SET_PRESET_POWERSAVE:
> + data->minimum = data->hw_lowest;
> + data->maximum = data->hw_lowest;
> + data->activity_window = 0;
> + if ( feature_hwp_energy_perf )
> + data->energy_perf = 0xff;
> + else
> + data->energy_perf = 0xf;
There may want to be constants #define-d for these, and ...
> + data->desired = 0;
> + break;
> + case XEN_SYSCTL_HWP_SET_PRESET_PERFORMANCE:
> + data->minimum = data->hw_highest;
> + data->maximum = data->hw_highest;
> + data->activity_window = 0;
> + data->energy_perf = 0;
> + data->desired = 0;
> + break;
> + case XEN_SYSCTL_HWP_SET_PRESET_BALANCE:
> + data->minimum = data->hw_lowest;
> + data->maximum = data->hw_highest;
> + data->activity_window = 0;
> + data->energy_perf = 0x80;
> + if ( feature_hwp_energy_perf )
> + data->energy_perf = 0x80;
> + else
> + data->energy_perf = 0x7;
... since these aren't the sole instances of these kind of magic
numbers there surely want to be #define-s for these (such that
the connection between the two [or more?] instances becomes
visible). Actually, the same applies to the 0xf further up, which
has a second use yet a few more lines up.
> + data->desired = 0;
> + break;
> + case XEN_SYSCTL_HWP_SET_PRESET_NONE:
> + break;
> + default:
> + printk("HWP: Invalid preset value: %u\n",
> + set_hwp->set_params & XEN_SYSCTL_HWP_SET_PRESET_MASK);
> +
> + return -EINVAL;
> + }
For the entire switch() - please have blank lines between (non-fall-
through, which here is all of them) case blocks.
> --- a/xen/drivers/acpi/pmstat.c
> +++ b/xen/drivers/acpi/pmstat.c
> @@ -318,6 +318,24 @@ static int set_cpufreq_gov(struct xen_sysctl_pm_op *op)
> return __cpufreq_set_policy(old_policy, &new_policy);
> }
>
> +static int set_cpufreq_hwp(struct xen_sysctl_pm_op *op)
> +{
> + struct cpufreq_policy *policy;
> +
> + if ( !cpufreq_governor_internal )
> + return -EINVAL;
> +
> + policy = per_cpu(cpufreq_cpu_policy, op->cpuid);
> +
> + if ( !policy || !policy->governor )
> + return -EINVAL;
> +
> + if ( strncasecmp(policy->governor->name, "hwp-internal", CPUFREQ_NAME_LEN) )
I think this recurring string literal also wants to at least gain
a #define.
> @@ -465,6 +483,12 @@ int do_pm_op(struct xen_sysctl_pm_op *op)
> break;
> }
>
> + case SET_CPUFREQ_HWP:
> + {
> + ret = set_cpufreq_hwp(op);
> + break;
> + }
> +
> case SET_CPUFREQ_PARA:
> {
> ret = set_cpufreq_para(op);
I think you want to insert somewhere below this one and, despite all
the odd precedents, omit the stray braces.
> --- a/xen/include/acpi/cpufreq/cpufreq.h
> +++ b/xen/include/acpi/cpufreq/cpufreq.h
> @@ -248,5 +248,7 @@ void cpufreq_dbs_timer_resume(void);
>
> /********************** hwp hypercall helper *************************/
> int get_hwp_para(struct cpufreq_policy *policy, struct xen_hwp_para *hwp_para);
> +int set_hwp_para(struct cpufreq_policy *policy,
> + struct xen_set_hwp_para *set_hwp);
This renders the comment stale - the patch introducing it probably
can use plural right away.
> --- a/xen/include/public/sysctl.h
> +++ b/xen/include/public/sysctl.h
> @@ -318,6 +318,36 @@ struct xen_hwp_para {
> uint8_t energy_perf;
> };
>
> +/* set multiple values simultaneously when set_args bit is set */
> +struct xen_set_hwp_para {
> + uint16_t set_params; /* bitflags for valid values */
> +#define XEN_SYSCTL_HWP_SET_DESIRED (1U << 0)
> +#define XEN_SYSCTL_HWP_SET_ENERGY_PERF (1U << 1)
> +#define XEN_SYSCTL_HWP_SET_ACT_WINDOW (1U << 2)
> +#define XEN_SYSCTL_HWP_SET_MINIMUM (1U << 3)
> +#define XEN_SYSCTL_HWP_SET_MAXIMUM (1U << 4)
> +#define XEN_SYSCTL_HWP_SET_PRESET_MASK (0xf000)
> +#define XEN_SYSCTL_HWP_SET_PRESET_NONE (0x0000)
> +#define XEN_SYSCTL_HWP_SET_PRESET_BALANCE (0x1000)
> +#define XEN_SYSCTL_HWP_SET_PRESET_POWERSAVE (0x2000)
> +#define XEN_SYSCTL_HWP_SET_PRESET_PERFORMANCE (0x3000)
Personally I'd prefer unnecessary parentheses (like around single
tokens) to be omitted.
> +#define XEN_SYSCTL_HWP_SET_PARAM_MASK ((uint16_t)( \
What's the reason for this cast? Wherever possible #define-d
constants should be suitable for use in preprocessor conditionals.
> + XEN_SYSCTL_HWP_SET_PRESET_MASK | \
> + XEN_SYSCTL_HWP_SET_DESIRED | \
> + XEN_SYSCTL_HWP_SET_ENERGY_PERF | \
> + XEN_SYSCTL_HWP_SET_ACT_WINDOW | \
> + XEN_SYSCTL_HWP_SET_MINIMUM | \
> + XEN_SYSCTL_HWP_SET_MAXIMUM ))
> +
> + uint16_t activity_window; /* 7bit mantissa and 3bit exponent */
Since the other respective comment is to be extended, perhaps here
you can simply refer to that one?
> +#define XEN_SYSCTL_HWP_ACT_WINDOW_MASK (0x03ff)
> + uint8_t minimum;
> + uint8_t maximum;
> + uint8_t desired;
> + uint8_t energy_perf; /* 0-255 or 0-15 depending on HW support */
> +};
> +
> +
No double blank lines please.
Jan
next prev parent reply other threads:[~2021-05-27 8:34 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-03 19:27 [PATCH 00/13] Intel Hardware P-States (HWP) support Jason Andryuk
2021-05-03 19:27 ` [PATCH 01/13] cpufreq: Allow restricting to internal governors only Jason Andryuk
2021-05-26 13:18 ` Jan Beulich
2021-05-26 14:12 ` Jason Andryuk
2021-05-26 15:09 ` Jan Beulich
2021-05-26 16:44 ` Jason Andryuk
2021-05-03 19:27 ` [PATCH 02/13] cpufreq: Add perf_freq to cpuinfo Jason Andryuk
2021-05-26 13:24 ` Jan Beulich
2021-05-26 14:19 ` Jason Andryuk
2021-05-03 19:28 ` [PATCH 03/13] cpufreq: Export intel_feature_detect Jason Andryuk
2021-05-26 13:27 ` Jan Beulich
2021-05-26 14:44 ` Jason Andryuk
2021-05-26 15:11 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 04/13] cpufreq: Add Hardware P-State (HWP) driver Jason Andryuk
2021-05-26 14:59 ` Jan Beulich
2021-05-27 7:23 ` Jan Beulich
2021-05-27 18:50 ` Jason Andryuk
2021-05-28 6:35 ` Jan Beulich
2021-06-03 11:55 ` Jason Andryuk
2021-06-04 6:39 ` Jan Beulich
2021-05-27 7:45 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 05/13] xenpm: Change get-cpufreq-para output for internal Jason Andryuk
2021-05-26 15:21 ` Jan Beulich
2021-05-27 5:54 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 06/13] cpufreq: Export HWP parameters to userspace Jason Andryuk
2021-05-27 7:55 ` Jan Beulich
2021-05-28 13:19 ` Jason Andryuk
2021-05-28 13:39 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 07/13] libxc: Include hwp_para in definitions Jason Andryuk
2021-05-03 19:28 ` [PATCH 08/13] xenpm: Print HWP parameters Jason Andryuk
2021-05-27 8:02 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 09/13] xen: Add SET_CPUFREQ_HWP xen_sysctl_pm_op Jason Andryuk
2021-05-27 8:33 ` Jan Beulich [this message]
2021-05-03 19:28 ` [PATCH 10/13] libxc: Add xc_set_cpufreq_hwp Jason Andryuk
2021-05-04 8:03 ` Jan Beulich
2021-05-04 11:31 ` Jason Andryuk
2021-05-27 9:45 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 11/13] xenpm: Factor out a non-fatal cpuid_parse variant Jason Andryuk
2021-05-27 8:41 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 12/13] xenpm: Add set-cpufreq-hwp subcommand Jason Andryuk
2021-05-27 9:46 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 13/13] CHANGELOG: Add Intel HWP entry Jason Andryuk
2021-05-27 9:48 ` Jan Beulich
2021-05-20 14:57 ` [PATCH 00/13] Intel Hardware P-States (HWP) support Jan Beulich
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