Re: [PATCH 5/7] cpufreq/cppc: Move and rename cppc_cpufreq_{perf_to_khz|khz_to_perf}

From: Rafael J. Wysocki
Date: Mon Nov 06 2023 - 09:26:33 EST

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In reply to: Vincent Guittot: "[PATCH 5/7] cpufreq/cppc: Move and rename cppc_cpufreq_{perf_to_khz|khz_to_perf}"
Next in thread: Vincent Guittot: "[PATCH v5 6/7] cpufreq/cppc: Set the frequency used for computing the capacity"
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On Sat, Nov 4, 2023 at 11:59 AM Vincent Guittot
<vincent.guittot@xxxxxxxxxx> wrote:
>
> Move and rename cppc_cpufreq_perf_to_khz and cppc_cpufreq_khz_to_perf to
> use them outside cppc_cpufreq in topology_init_cpu_capacity_cppc().
>
> Modify the interface to use struct cppc_perf_caps *caps instead of
> struct cppc_cpudata *cpu_data as we only use the fields of cppc_perf_caps.
>
> cppc_cpufreq was converting the lowest and nominal freq from MHz to kHz
> before using them. We move this conversion inside cppc_perf_to_khz and
> cppc_khz_to_perf to make them generic and usable outside cppc_cpufreq.
>
> No functional change
>
> Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>

Acked-by: Rafael J. Wysocki <rafael@xxxxxxxxxx>

> ---
> drivers/acpi/cppc_acpi.c | 104 ++++++++++++++++++++++++
> drivers/cpufreq/cppc_cpufreq.c | 139 ++++-----------------------------
> include/acpi/cppc_acpi.h | 2 +
> 3 files changed, 123 insertions(+), 122 deletions(-)
>
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index 7ff269a78c20..d155a86a8614 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -39,6 +39,9 @@
> #include <linux/rwsem.h>
> #include <linux/wait.h>
> #include <linux/topology.h>
> +#include <linux/dmi.h>
> +#include <linux/units.h>
> +#include <asm/unaligned.h>
>
> #include <acpi/cppc_acpi.h>
>
> @@ -1760,3 +1763,104 @@ unsigned int cppc_get_transition_latency(int cpu_num)
> return latency_ns;
> }
> EXPORT_SYMBOL_GPL(cppc_get_transition_latency);
> +
> +/* Minimum struct length needed for the DMI processor entry we want */
> +#define DMI_ENTRY_PROCESSOR_MIN_LENGTH 48
> +
> +/* Offset in the DMI processor structure for the max frequency */
> +#define DMI_PROCESSOR_MAX_SPEED 0x14
> +
> +/* Callback function used to retrieve the max frequency from DMI */
> +static void cppc_find_dmi_mhz(const struct dmi_header *dm, void *private)
> +{
> + const u8 *dmi_data = (const u8 *)dm;
> + u16 *mhz = (u16 *)private;
> +
> + if (dm->type == DMI_ENTRY_PROCESSOR &&
> + dm->length >= DMI_ENTRY_PROCESSOR_MIN_LENGTH) {
> + u16 val = (u16)get_unaligned((const u16 *)
> + (dmi_data + DMI_PROCESSOR_MAX_SPEED));
> + *mhz = val > *mhz ? val : *mhz;
> + }
> +}
> +
> +/* Look up the max frequency in DMI */
> +static u64 cppc_get_dmi_max_khz(void)
> +{
> + u16 mhz = 0;
> +
> + dmi_walk(cppc_find_dmi_mhz, &mhz);
> +
> + /*
> + * Real stupid fallback value, just in case there is no
> + * actual value set.
> + */
> + mhz = mhz ? mhz : 1;
> +
> + return KHZ_PER_MHZ * mhz;
> +}
> +
> +/*
> + * If CPPC lowest_freq and nominal_freq registers are exposed then we can
> + * use them to convert perf to freq and vice versa. The conversion is
> + * extrapolated as an affine function passing by the 2 points:
> + * - (Low perf, Low freq)
> + * - (Nominal perf, Nominal freq)
> + */
> +unsigned int cppc_perf_to_khz(struct cppc_perf_caps *caps, unsigned int perf)
> +{
> + s64 retval, offset = 0;
> + static u64 max_khz;
> + u64 mul, div;
> +
> + if (caps->lowest_freq && caps->nominal_freq) {
> + mul = caps->nominal_freq - caps->lowest_freq;
> + mul *= KHZ_PER_MHZ;
> + div = caps->nominal_perf - caps->lowest_perf;
> + offset = caps->nominal_freq * KHZ_PER_MHZ -
> + div64_u64(caps->nominal_perf * mul, div);
> + } else {
> + if (!max_khz)
> + max_khz = cppc_get_dmi_max_khz();
> + mul = max_khz;
> + div = caps->highest_perf;
> + }
> +
> + retval = offset + div64_u64(perf * mul, div);
> + if (retval >= 0)
> + return retval;
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(cppc_perf_to_khz);
> +
> +unsigned int cppc_khz_to_perf(struct cppc_perf_caps *caps, unsigned int freq)
> +{
> + s64 retval, offset = 0;
> + static u64 max_khz;
> + u64 mul, div;
> +
> + if (caps->lowest_freq && caps->nominal_freq) {
> + mul = caps->nominal_perf - caps->lowest_perf;
> + div = caps->nominal_freq - caps->lowest_freq;
> + /*
> + * We don't need to convert to kHz for computing offset and can
> + * directly use nominal_freq and lowest_freq as the div64_u64
> + * will remove the frequency unit.
> + */
> + offset = caps->nominal_perf -
> + div64_u64(caps->nominal_freq * mul, div);
> + /* But we need it for computing the perf level. */
> + div *= KHZ_PER_MHZ;
> + } else {
> + if (!max_khz)
> + max_khz = cppc_get_dmi_max_khz();
> + mul = caps->highest_perf;
> + div = max_khz;
> + }
> +
> + retval = offset + div64_u64(freq * mul, div);
> + if (retval >= 0)
> + return retval;
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(cppc_khz_to_perf);
> diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
> index fe08ca419b3d..64420d9cfd1e 100644
> --- a/drivers/cpufreq/cppc_cpufreq.c
> +++ b/drivers/cpufreq/cppc_cpufreq.c
> @@ -16,7 +16,6 @@
> #include <linux/delay.h>
> #include <linux/cpu.h>
> #include <linux/cpufreq.h>
> -#include <linux/dmi.h>
> #include <linux/irq_work.h>
> #include <linux/kthread.h>
> #include <linux/time.h>
> @@ -27,12 +26,6 @@
>
> #include <acpi/cppc_acpi.h>
>
> -/* Minimum struct length needed for the DMI processor entry we want */
> -#define DMI_ENTRY_PROCESSOR_MIN_LENGTH 48
> -
> -/* Offset in the DMI processor structure for the max frequency */
> -#define DMI_PROCESSOR_MAX_SPEED 0x14
> -
> /*
> * This list contains information parsed from per CPU ACPI _CPC and _PSD
> * structures: e.g. the highest and lowest supported performance, capabilities,
> @@ -291,97 +284,9 @@ static inline void cppc_freq_invariance_exit(void)
> }
> #endif /* CONFIG_ACPI_CPPC_CPUFREQ_FIE */
>
> -/* Callback function used to retrieve the max frequency from DMI */
> -static void cppc_find_dmi_mhz(const struct dmi_header *dm, void *private)
> -{
> - const u8 *dmi_data = (const u8 *)dm;
> - u16 *mhz = (u16 *)private;
> -
> - if (dm->type == DMI_ENTRY_PROCESSOR &&
> - dm->length >= DMI_ENTRY_PROCESSOR_MIN_LENGTH) {
> - u16 val = (u16)get_unaligned((const u16 *)
> - (dmi_data + DMI_PROCESSOR_MAX_SPEED));
> - *mhz = val > *mhz ? val : *mhz;
> - }
> -}
> -
> -/* Look up the max frequency in DMI */
> -static u64 cppc_get_dmi_max_khz(void)
> -{
> - u16 mhz = 0;
> -
> - dmi_walk(cppc_find_dmi_mhz, &mhz);
> -
> - /*
> - * Real stupid fallback value, just in case there is no
> - * actual value set.
> - */
> - mhz = mhz ? mhz : 1;
> -
> - return (1000 * mhz);
> -}
> -
> -/*
> - * If CPPC lowest_freq and nominal_freq registers are exposed then we can
> - * use them to convert perf to freq and vice versa. The conversion is
> - * extrapolated as an affine function passing by the 2 points:
> - * - (Low perf, Low freq)
> - * - (Nominal perf, Nominal perf)
> - */
> -static unsigned int cppc_cpufreq_perf_to_khz(struct cppc_cpudata *cpu_data,
> - unsigned int perf)
> -{
> - struct cppc_perf_caps *caps = &cpu_data->perf_caps;
> - s64 retval, offset = 0;
> - static u64 max_khz;
> - u64 mul, div;
> -
> - if (caps->lowest_freq && caps->nominal_freq) {
> - mul = caps->nominal_freq - caps->lowest_freq;
> - div = caps->nominal_perf - caps->lowest_perf;
> - offset = caps->nominal_freq - div64_u64(caps->nominal_perf * mul, div);
> - } else {
> - if (!max_khz)
> - max_khz = cppc_get_dmi_max_khz();
> - mul = max_khz;
> - div = caps->highest_perf;
> - }
> -
> - retval = offset + div64_u64(perf * mul, div);
> - if (retval >= 0)
> - return retval;
> - return 0;
> -}
> -
> -static unsigned int cppc_cpufreq_khz_to_perf(struct cppc_cpudata *cpu_data,
> - unsigned int freq)
> -{
> - struct cppc_perf_caps *caps = &cpu_data->perf_caps;
> - s64 retval, offset = 0;
> - static u64 max_khz;
> - u64 mul, div;
> -
> - if (caps->lowest_freq && caps->nominal_freq) {
> - mul = caps->nominal_perf - caps->lowest_perf;
> - div = caps->nominal_freq - caps->lowest_freq;
> - offset = caps->nominal_perf - div64_u64(caps->nominal_freq * mul, div);
> - } else {
> - if (!max_khz)
> - max_khz = cppc_get_dmi_max_khz();
> - mul = caps->highest_perf;
> - div = max_khz;
> - }
> -
> - retval = offset + div64_u64(freq * mul, div);
> - if (retval >= 0)
> - return retval;
> - return 0;
> -}
> -
> static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
> unsigned int target_freq,
> unsigned int relation)
> -
> {
> struct cppc_cpudata *cpu_data = policy->driver_data;
> unsigned int cpu = policy->cpu;
> @@ -389,7 +294,7 @@ static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
> u32 desired_perf;
> int ret = 0;
>
> - desired_perf = cppc_cpufreq_khz_to_perf(cpu_data, target_freq);
> + desired_perf = cppc_khz_to_perf(&cpu_data->perf_caps, target_freq);
> /* Return if it is exactly the same perf */
> if (desired_perf == cpu_data->perf_ctrls.desired_perf)
> return ret;
> @@ -417,7 +322,7 @@ static unsigned int cppc_cpufreq_fast_switch(struct cpufreq_policy *policy,
> u32 desired_perf;
> int ret;
>
> - desired_perf = cppc_cpufreq_khz_to_perf(cpu_data, target_freq);
> + desired_perf = cppc_khz_to_perf(&cpu_data->perf_caps, target_freq);
> cpu_data->perf_ctrls.desired_perf = desired_perf;
> ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
>
> @@ -530,7 +435,7 @@ static int cppc_get_cpu_power(struct device *cpu_dev,
> min_step = min_cap / CPPC_EM_CAP_STEP;
> max_step = max_cap / CPPC_EM_CAP_STEP;
>
> - perf_prev = cppc_cpufreq_khz_to_perf(cpu_data, *KHz);
> + perf_prev = cppc_khz_to_perf(perf_caps, *KHz);
> step = perf_prev / perf_step;
>
> if (step > max_step)
> @@ -550,8 +455,8 @@ static int cppc_get_cpu_power(struct device *cpu_dev,
> perf = step * perf_step;
> }
>
> - *KHz = cppc_cpufreq_perf_to_khz(cpu_data, perf);
> - perf_check = cppc_cpufreq_khz_to_perf(cpu_data, *KHz);
> + *KHz = cppc_perf_to_khz(perf_caps, perf);
> + perf_check = cppc_khz_to_perf(perf_caps, *KHz);
> step_check = perf_check / perf_step;
>
> /*
> @@ -561,8 +466,8 @@ static int cppc_get_cpu_power(struct device *cpu_dev,
> */
> while ((*KHz == prev_freq) || (step_check != step)) {
> perf++;
> - *KHz = cppc_cpufreq_perf_to_khz(cpu_data, perf);
> - perf_check = cppc_cpufreq_khz_to_perf(cpu_data, *KHz);
> + *KHz = cppc_perf_to_khz(perf_caps, perf);
> + perf_check = cppc_khz_to_perf(perf_caps, *KHz);
> step_check = perf_check / perf_step;
> }
>
> @@ -591,7 +496,7 @@ static int cppc_get_cpu_cost(struct device *cpu_dev, unsigned long KHz,
> perf_caps = &cpu_data->perf_caps;
> max_cap = arch_scale_cpu_capacity(cpu_dev->id);
>
> - perf_prev = cppc_cpufreq_khz_to_perf(cpu_data, KHz);
> + perf_prev = cppc_khz_to_perf(perf_caps, KHz);
> perf_step = CPPC_EM_CAP_STEP * perf_caps->highest_perf / max_cap;
> step = perf_prev / perf_step;
>
> @@ -679,10 +584,6 @@ static struct cppc_cpudata *cppc_cpufreq_get_cpu_data(unsigned int cpu)
> goto free_mask;
> }
>
> - /* Convert the lowest and nominal freq from MHz to KHz */
> - cpu_data->perf_caps.lowest_freq *= 1000;
> - cpu_data->perf_caps.nominal_freq *= 1000;
> -
> list_add(&cpu_data->node, &cpu_data_list);
>
> return cpu_data;
> @@ -724,20 +625,16 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
> * Set min to lowest nonlinear perf to avoid any efficiency penalty (see
> * Section 8.4.7.1.1.5 of ACPI 6.1 spec)
> */
> - policy->min = cppc_cpufreq_perf_to_khz(cpu_data,
> - caps->lowest_nonlinear_perf);
> - policy->max = cppc_cpufreq_perf_to_khz(cpu_data,
> - caps->nominal_perf);
> + policy->min = cppc_perf_to_khz(caps, caps->lowest_nonlinear_perf);
> + policy->max = cppc_perf_to_khz(caps, caps->nominal_perf);
>
> /*
> * Set cpuinfo.min_freq to Lowest to make the full range of performance
> * available if userspace wants to use any perf between lowest & lowest
> * nonlinear perf
> */
> - policy->cpuinfo.min_freq = cppc_cpufreq_perf_to_khz(cpu_data,
> - caps->lowest_perf);
> - policy->cpuinfo.max_freq = cppc_cpufreq_perf_to_khz(cpu_data,
> - caps->nominal_perf);
> + policy->cpuinfo.min_freq = cppc_perf_to_khz(caps, caps->lowest_perf);
> + policy->cpuinfo.max_freq = cppc_perf_to_khz(caps, caps->nominal_perf);
>
> policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu);
> policy->shared_type = cpu_data->shared_type;
> @@ -773,7 +670,7 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
> boost_supported = true;
>
> /* Set policy->cur to max now. The governors will adjust later. */
> - policy->cur = cppc_cpufreq_perf_to_khz(cpu_data, caps->highest_perf);
> + policy->cur = cppc_perf_to_khz(caps, caps->highest_perf);
> cpu_data->perf_ctrls.desired_perf = caps->highest_perf;
>
> ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
> @@ -863,7 +760,7 @@ static unsigned int cppc_cpufreq_get_rate(unsigned int cpu)
> delivered_perf = cppc_perf_from_fbctrs(cpu_data, &fb_ctrs_t0,
> &fb_ctrs_t1);
>
> - return cppc_cpufreq_perf_to_khz(cpu_data, delivered_perf);
> + return cppc_perf_to_khz(&cpu_data->perf_caps, delivered_perf);
> }
>
> static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state)
> @@ -878,11 +775,9 @@ static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state)
> }
>
> if (state)
> - policy->max = cppc_cpufreq_perf_to_khz(cpu_data,
> - caps->highest_perf);
> + policy->max = cppc_perf_to_khz(caps, caps->highest_perf);
> else
> - policy->max = cppc_cpufreq_perf_to_khz(cpu_data,
> - caps->nominal_perf);
> + policy->max = cppc_perf_to_khz(caps, caps->nominal_perf);
> policy->cpuinfo.max_freq = policy->max;
>
> ret = freq_qos_update_request(policy->max_freq_req, policy->max);
> @@ -937,7 +832,7 @@ static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpu)
> if (ret < 0)
> return -EIO;
>
> - return cppc_cpufreq_perf_to_khz(cpu_data, desired_perf);
> + return cppc_perf_to_khz(&cpu_data->perf_caps, desired_perf);
> }
>
> static void cppc_check_hisi_workaround(void)
> diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
> index 6126c977ece0..3a0995f8bce8 100644
> --- a/include/acpi/cppc_acpi.h
> +++ b/include/acpi/cppc_acpi.h
> @@ -144,6 +144,8 @@ extern int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls);
> extern int cppc_set_enable(int cpu, bool enable);
> extern int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps);
> extern bool cppc_perf_ctrs_in_pcc(void);
> +extern unsigned int cppc_perf_to_khz(struct cppc_perf_caps *caps, unsigned int perf);
> +extern unsigned int cppc_khz_to_perf(struct cppc_perf_caps *caps, unsigned int freq);
> extern bool acpi_cpc_valid(void);
> extern bool cppc_allow_fast_switch(void);
> extern int acpi_get_psd_map(unsigned int cpu, struct cppc_cpudata *cpu_data);
> --
> 2.34.1
>

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Previous message: Ulf Hansson: "Re: [PATCH] mmc: sdhci-sprd: Fix the clock switch"
In reply to: Vincent Guittot: "[PATCH 5/7] cpufreq/cppc: Move and rename cppc_cpufreq_{perf_to_khz|khz_to_perf}"
Next in thread: Vincent Guittot: "[PATCH v5 6/7] cpufreq/cppc: Set the frequency used for computing the capacity"
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