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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /drivers/cpufreq/cppc_cpufreq.c
parentInitial commit. (diff)
downloadlinux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz
linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/cpufreq/cppc_cpufreq.c')
-rw-r--r--drivers/cpufreq/cppc_cpufreq.c529
1 files changed, 529 insertions, 0 deletions
diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
new file mode 100644
index 000000000..f29e8d055
--- /dev/null
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -0,0 +1,529 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * CPPC (Collaborative Processor Performance Control) driver for
+ * interfacing with the CPUfreq layer and governors. See
+ * cppc_acpi.c for CPPC specific methods.
+ *
+ * (C) Copyright 2014, 2015 Linaro Ltd.
+ * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
+ */
+
+#define pr_fmt(fmt) "CPPC Cpufreq:" fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/dmi.h>
+#include <linux/time.h>
+#include <linux/vmalloc.h>
+
+#include <asm/unaligned.h>
+
+#include <acpi/cppc_acpi.h>
+
+/* Minimum struct length needed for the DMI processor entry we want */
+#define DMI_ENTRY_PROCESSOR_MIN_LENGTH 48
+
+/* Offest in the DMI processor structure for the max frequency */
+#define DMI_PROCESSOR_MAX_SPEED 0x14
+
+/*
+ * These structs contain information parsed from per CPU
+ * ACPI _CPC structures.
+ * e.g. For each CPU the highest, lowest supported
+ * performance capabilities, desired performance level
+ * requested etc.
+ */
+static struct cppc_cpudata **all_cpu_data;
+static bool boost_supported;
+
+struct cppc_workaround_oem_info {
+ char oem_id[ACPI_OEM_ID_SIZE + 1];
+ char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
+ u32 oem_revision;
+};
+
+static struct cppc_workaround_oem_info wa_info[] = {
+ {
+ .oem_id = "HISI ",
+ .oem_table_id = "HIP07 ",
+ .oem_revision = 0,
+ }, {
+ .oem_id = "HISI ",
+ .oem_table_id = "HIP08 ",
+ .oem_revision = 0,
+ }
+};
+
+/* 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
+ *
+ * If the perf/freq point lies between Nominal and Lowest, we can treat
+ * (Low perf, Low freq) and (Nom Perf, Nom freq) as 2D co-ordinates of a line
+ * and extrapolate the rest
+ * For perf/freq > Nominal, we use the ratio perf:freq at Nominal for conversion
+ */
+static unsigned int cppc_cpufreq_perf_to_khz(struct cppc_cpudata *cpu,
+ unsigned int perf)
+{
+ static u64 max_khz;
+ struct cppc_perf_caps *caps = &cpu->perf_caps;
+ u64 mul, div;
+
+ if (caps->lowest_freq && caps->nominal_freq) {
+ if (perf >= caps->nominal_perf) {
+ mul = caps->nominal_freq;
+ div = caps->nominal_perf;
+ } else {
+ mul = caps->nominal_freq - caps->lowest_freq;
+ div = caps->nominal_perf - caps->lowest_perf;
+ }
+ } else {
+ if (!max_khz)
+ max_khz = cppc_get_dmi_max_khz();
+ mul = max_khz;
+ div = caps->highest_perf;
+ }
+ return (u64)perf * mul / div;
+}
+
+static unsigned int cppc_cpufreq_khz_to_perf(struct cppc_cpudata *cpu,
+ unsigned int freq)
+{
+ static u64 max_khz;
+ struct cppc_perf_caps *caps = &cpu->perf_caps;
+ u64 mul, div;
+
+ if (caps->lowest_freq && caps->nominal_freq) {
+ if (freq >= caps->nominal_freq) {
+ mul = caps->nominal_perf;
+ div = caps->nominal_freq;
+ } else {
+ mul = caps->lowest_perf;
+ div = caps->lowest_freq;
+ }
+ } else {
+ if (!max_khz)
+ max_khz = cppc_get_dmi_max_khz();
+ mul = caps->highest_perf;
+ div = max_khz;
+ }
+
+ return (u64)freq * mul / div;
+}
+
+static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ struct cppc_cpudata *cpu;
+ struct cpufreq_freqs freqs;
+ u32 desired_perf;
+ int ret = 0;
+
+ cpu = all_cpu_data[policy->cpu];
+
+ desired_perf = cppc_cpufreq_khz_to_perf(cpu, target_freq);
+ /* Return if it is exactly the same perf */
+ if (desired_perf == cpu->perf_ctrls.desired_perf)
+ return ret;
+
+ cpu->perf_ctrls.desired_perf = desired_perf;
+ freqs.old = policy->cur;
+ freqs.new = target_freq;
+
+ cpufreq_freq_transition_begin(policy, &freqs);
+ ret = cppc_set_perf(cpu->cpu, &cpu->perf_ctrls);
+ cpufreq_freq_transition_end(policy, &freqs, ret != 0);
+
+ if (ret)
+ pr_debug("Failed to set target on CPU:%d. ret:%d\n",
+ cpu->cpu, ret);
+
+ return ret;
+}
+
+static int cppc_verify_policy(struct cpufreq_policy_data *policy)
+{
+ cpufreq_verify_within_cpu_limits(policy);
+ return 0;
+}
+
+static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy)
+{
+ int cpu_num = policy->cpu;
+ struct cppc_cpudata *cpu = all_cpu_data[cpu_num];
+ int ret;
+
+ cpu->perf_ctrls.desired_perf = cpu->perf_caps.lowest_perf;
+
+ ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
+ if (ret)
+ pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
+ cpu->perf_caps.lowest_perf, cpu_num, ret);
+}
+
+/*
+ * The PCC subspace describes the rate at which platform can accept commands
+ * on the shared PCC channel (including READs which do not count towards freq
+ * trasition requests), so ideally we need to use the PCC values as a fallback
+ * if we don't have a platform specific transition_delay_us
+ */
+#ifdef CONFIG_ARM64
+#include <asm/cputype.h>
+
+static unsigned int cppc_cpufreq_get_transition_delay_us(int cpu)
+{
+ unsigned long implementor = read_cpuid_implementor();
+ unsigned long part_num = read_cpuid_part_number();
+ unsigned int delay_us = 0;
+
+ switch (implementor) {
+ case ARM_CPU_IMP_QCOM:
+ switch (part_num) {
+ case QCOM_CPU_PART_FALKOR_V1:
+ case QCOM_CPU_PART_FALKOR:
+ delay_us = 10000;
+ break;
+ default:
+ delay_us = cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
+ break;
+ }
+ break;
+ default:
+ delay_us = cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
+ break;
+ }
+
+ return delay_us;
+}
+
+#else
+
+static unsigned int cppc_cpufreq_get_transition_delay_us(int cpu)
+{
+ return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
+}
+#endif
+
+static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+ struct cppc_cpudata *cpu;
+ unsigned int cpu_num = policy->cpu;
+ int ret = 0;
+
+ cpu = all_cpu_data[policy->cpu];
+
+ cpu->cpu = cpu_num;
+ ret = cppc_get_perf_caps(policy->cpu, &cpu->perf_caps);
+
+ if (ret) {
+ pr_debug("Err reading CPU%d perf capabilities. ret:%d\n",
+ cpu_num, ret);
+ return ret;
+ }
+
+ /* Convert the lowest and nominal freq from MHz to KHz */
+ cpu->perf_caps.lowest_freq *= 1000;
+ cpu->perf_caps.nominal_freq *= 1000;
+
+ /*
+ * 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, cpu->perf_caps.lowest_nonlinear_perf);
+ policy->max = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_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, cpu->perf_caps.lowest_perf);
+ policy->cpuinfo.max_freq = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.nominal_perf);
+
+ policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu_num);
+ policy->shared_type = cpu->shared_type;
+
+ if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
+ int i;
+
+ cpumask_copy(policy->cpus, cpu->shared_cpu_map);
+
+ for_each_cpu(i, policy->cpus) {
+ if (unlikely(i == policy->cpu))
+ continue;
+
+ memcpy(&all_cpu_data[i]->perf_caps, &cpu->perf_caps,
+ sizeof(cpu->perf_caps));
+ }
+ } else if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL) {
+ /* Support only SW_ANY for now. */
+ pr_debug("Unsupported CPU co-ord type\n");
+ return -EFAULT;
+ }
+
+ cpu->cur_policy = policy;
+
+ /*
+ * If 'highest_perf' is greater than 'nominal_perf', we assume CPU Boost
+ * is supported.
+ */
+ if (cpu->perf_caps.highest_perf > cpu->perf_caps.nominal_perf)
+ boost_supported = true;
+
+ /* Set policy->cur to max now. The governors will adjust later. */
+ policy->cur = cppc_cpufreq_perf_to_khz(cpu,
+ cpu->perf_caps.highest_perf);
+ cpu->perf_ctrls.desired_perf = cpu->perf_caps.highest_perf;
+
+ ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
+ if (ret)
+ pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
+ cpu->perf_caps.highest_perf, cpu_num, ret);
+
+ return ret;
+}
+
+static inline u64 get_delta(u64 t1, u64 t0)
+{
+ if (t1 > t0 || t0 > ~(u32)0)
+ return t1 - t0;
+
+ return (u32)t1 - (u32)t0;
+}
+
+static int cppc_get_rate_from_fbctrs(struct cppc_cpudata *cpu,
+ struct cppc_perf_fb_ctrs fb_ctrs_t0,
+ struct cppc_perf_fb_ctrs fb_ctrs_t1)
+{
+ u64 delta_reference, delta_delivered;
+ u64 reference_perf, delivered_perf;
+
+ reference_perf = fb_ctrs_t0.reference_perf;
+
+ delta_reference = get_delta(fb_ctrs_t1.reference,
+ fb_ctrs_t0.reference);
+ delta_delivered = get_delta(fb_ctrs_t1.delivered,
+ fb_ctrs_t0.delivered);
+
+ /* Check to avoid divide-by zero */
+ if (delta_reference || delta_delivered)
+ delivered_perf = (reference_perf * delta_delivered) /
+ delta_reference;
+ else
+ delivered_perf = cpu->perf_ctrls.desired_perf;
+
+ return cppc_cpufreq_perf_to_khz(cpu, delivered_perf);
+}
+
+static unsigned int cppc_cpufreq_get_rate(unsigned int cpunum)
+{
+ struct cppc_perf_fb_ctrs fb_ctrs_t0 = {0}, fb_ctrs_t1 = {0};
+ struct cppc_cpudata *cpu = all_cpu_data[cpunum];
+ int ret;
+
+ ret = cppc_get_perf_ctrs(cpunum, &fb_ctrs_t0);
+ if (ret)
+ return ret;
+
+ udelay(2); /* 2usec delay between sampling */
+
+ ret = cppc_get_perf_ctrs(cpunum, &fb_ctrs_t1);
+ if (ret)
+ return ret;
+
+ return cppc_get_rate_from_fbctrs(cpu, fb_ctrs_t0, fb_ctrs_t1);
+}
+
+static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state)
+{
+ struct cppc_cpudata *cpudata;
+ int ret;
+
+ if (!boost_supported) {
+ pr_err("BOOST not supported by CPU or firmware\n");
+ return -EINVAL;
+ }
+
+ cpudata = all_cpu_data[policy->cpu];
+ if (state)
+ policy->max = cppc_cpufreq_perf_to_khz(cpudata,
+ cpudata->perf_caps.highest_perf);
+ else
+ policy->max = cppc_cpufreq_perf_to_khz(cpudata,
+ cpudata->perf_caps.nominal_perf);
+ policy->cpuinfo.max_freq = policy->max;
+
+ ret = freq_qos_update_request(policy->max_freq_req, policy->max);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static struct cpufreq_driver cppc_cpufreq_driver = {
+ .flags = CPUFREQ_CONST_LOOPS,
+ .verify = cppc_verify_policy,
+ .target = cppc_cpufreq_set_target,
+ .get = cppc_cpufreq_get_rate,
+ .init = cppc_cpufreq_cpu_init,
+ .stop_cpu = cppc_cpufreq_stop_cpu,
+ .set_boost = cppc_cpufreq_set_boost,
+ .name = "cppc_cpufreq",
+};
+
+/*
+ * HISI platform does not support delivered performance counter and
+ * reference performance counter. It can calculate the performance using the
+ * platform specific mechanism. We reuse the desired performance register to
+ * store the real performance calculated by the platform.
+ */
+static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpunum)
+{
+ struct cppc_cpudata *cpudata = all_cpu_data[cpunum];
+ u64 desired_perf;
+ int ret;
+
+ ret = cppc_get_desired_perf(cpunum, &desired_perf);
+ if (ret < 0)
+ return -EIO;
+
+ return cppc_cpufreq_perf_to_khz(cpudata, desired_perf);
+}
+
+static void cppc_check_hisi_workaround(void)
+{
+ struct acpi_table_header *tbl;
+ acpi_status status = AE_OK;
+ int i;
+
+ status = acpi_get_table(ACPI_SIG_PCCT, 0, &tbl);
+ if (ACPI_FAILURE(status) || !tbl)
+ return;
+
+ for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
+ if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE) &&
+ !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
+ wa_info[i].oem_revision == tbl->oem_revision) {
+ /* Overwrite the get() callback */
+ cppc_cpufreq_driver.get = hisi_cppc_cpufreq_get_rate;
+ break;
+ }
+ }
+
+ acpi_put_table(tbl);
+}
+
+static int __init cppc_cpufreq_init(void)
+{
+ int i, ret = 0;
+ struct cppc_cpudata *cpu;
+
+ if (acpi_disabled)
+ return -ENODEV;
+
+ all_cpu_data = kcalloc(num_possible_cpus(), sizeof(void *),
+ GFP_KERNEL);
+ if (!all_cpu_data)
+ return -ENOMEM;
+
+ for_each_possible_cpu(i) {
+ all_cpu_data[i] = kzalloc(sizeof(struct cppc_cpudata), GFP_KERNEL);
+ if (!all_cpu_data[i])
+ goto out;
+
+ cpu = all_cpu_data[i];
+ if (!zalloc_cpumask_var(&cpu->shared_cpu_map, GFP_KERNEL))
+ goto out;
+ }
+
+ ret = acpi_get_psd_map(all_cpu_data);
+ if (ret) {
+ pr_debug("Error parsing PSD data. Aborting cpufreq registration.\n");
+ goto out;
+ }
+
+ cppc_check_hisi_workaround();
+
+ ret = cpufreq_register_driver(&cppc_cpufreq_driver);
+ if (ret)
+ goto out;
+
+ return ret;
+
+out:
+ for_each_possible_cpu(i) {
+ cpu = all_cpu_data[i];
+ if (!cpu)
+ break;
+ free_cpumask_var(cpu->shared_cpu_map);
+ kfree(cpu);
+ }
+
+ kfree(all_cpu_data);
+ return -ENODEV;
+}
+
+static void __exit cppc_cpufreq_exit(void)
+{
+ struct cppc_cpudata *cpu;
+ int i;
+
+ cpufreq_unregister_driver(&cppc_cpufreq_driver);
+
+ for_each_possible_cpu(i) {
+ cpu = all_cpu_data[i];
+ free_cpumask_var(cpu->shared_cpu_map);
+ kfree(cpu);
+ }
+
+ kfree(all_cpu_data);
+}
+
+module_exit(cppc_cpufreq_exit);
+MODULE_AUTHOR("Ashwin Chaugule");
+MODULE_DESCRIPTION("CPUFreq driver based on the ACPI CPPC v5.0+ spec");
+MODULE_LICENSE("GPL");
+
+late_initcall(cppc_cpufreq_init);
+
+static const struct acpi_device_id cppc_acpi_ids[] __used = {
+ {ACPI_PROCESSOR_DEVICE_HID, },
+ {}
+};
+
+MODULE_DEVICE_TABLE(acpi, cppc_acpi_ids);