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-rw-r--r--drivers/acpi/processor_thermal.c265
1 files changed, 265 insertions, 0 deletions
diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
new file mode 100644
index 000000000..7df0c6e3b
--- /dev/null
+++ b/drivers/acpi/processor_thermal.c
@@ -0,0 +1,265 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * processor_thermal.c - Passive cooling submodule of the ACPI processor driver
+ *
+ * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
+ * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
+ * - Added processor hotplug support
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/acpi.h>
+#include <acpi/processor.h>
+#include <linux/uaccess.h>
+
+#define PREFIX "ACPI: "
+
+#define ACPI_PROCESSOR_CLASS "processor"
+
+#ifdef CONFIG_CPU_FREQ
+
+/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
+ * offers (in most cases) voltage scaling in addition to frequency scaling, and
+ * thus a cubic (instead of linear) reduction of energy. Also, we allow for
+ * _any_ cpufreq driver and not only the acpi-cpufreq driver.
+ */
+
+#define CPUFREQ_THERMAL_MIN_STEP 0
+#define CPUFREQ_THERMAL_MAX_STEP 3
+
+static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
+
+#define reduction_pctg(cpu) \
+ per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu))
+
+/*
+ * Emulate "per package data" using per cpu data (which should really be
+ * provided elsewhere)
+ *
+ * Note we can lose a CPU on cpu hotunplug, in this case we forget the state
+ * temporarily. Fortunately that's not a big issue here (I hope)
+ */
+static int phys_package_first_cpu(int cpu)
+{
+ int i;
+ int id = topology_physical_package_id(cpu);
+
+ for_each_online_cpu(i)
+ if (topology_physical_package_id(i) == id)
+ return i;
+ return 0;
+}
+
+static int cpu_has_cpufreq(unsigned int cpu)
+{
+ struct cpufreq_policy policy;
+ if (!acpi_processor_cpufreq_init || cpufreq_get_policy(&policy, cpu))
+ return 0;
+ return 1;
+}
+
+static int cpufreq_get_max_state(unsigned int cpu)
+{
+ if (!cpu_has_cpufreq(cpu))
+ return 0;
+
+ return CPUFREQ_THERMAL_MAX_STEP;
+}
+
+static int cpufreq_get_cur_state(unsigned int cpu)
+{
+ if (!cpu_has_cpufreq(cpu))
+ return 0;
+
+ return reduction_pctg(cpu);
+}
+
+static int cpufreq_set_cur_state(unsigned int cpu, int state)
+{
+ struct cpufreq_policy *policy;
+ struct acpi_processor *pr;
+ unsigned long max_freq;
+ int i, ret;
+
+ if (!cpu_has_cpufreq(cpu))
+ return 0;
+
+ reduction_pctg(cpu) = state;
+
+ /*
+ * Update all the CPUs in the same package because they all
+ * contribute to the temperature and often share the same
+ * frequency.
+ */
+ for_each_online_cpu(i) {
+ if (topology_physical_package_id(i) !=
+ topology_physical_package_id(cpu))
+ continue;
+
+ pr = per_cpu(processors, i);
+
+ if (unlikely(!freq_qos_request_active(&pr->thermal_req)))
+ continue;
+
+ policy = cpufreq_cpu_get(i);
+ if (!policy)
+ return -EINVAL;
+
+ max_freq = (policy->cpuinfo.max_freq * (100 - reduction_pctg(i) * 20)) / 100;
+
+ cpufreq_cpu_put(policy);
+
+ ret = freq_qos_update_request(&pr->thermal_req, max_freq);
+ if (ret < 0) {
+ pr_warn("Failed to update thermal freq constraint: CPU%d (%d)\n",
+ pr->id, ret);
+ }
+ }
+ return 0;
+}
+
+void acpi_thermal_cpufreq_init(struct cpufreq_policy *policy)
+{
+ unsigned int cpu;
+
+ for_each_cpu(cpu, policy->related_cpus) {
+ struct acpi_processor *pr = per_cpu(processors, cpu);
+ int ret;
+
+ if (!pr)
+ continue;
+
+ ret = freq_qos_add_request(&policy->constraints,
+ &pr->thermal_req,
+ FREQ_QOS_MAX, INT_MAX);
+ if (ret < 0)
+ pr_err("Failed to add freq constraint for CPU%d (%d)\n",
+ cpu, ret);
+ }
+}
+
+void acpi_thermal_cpufreq_exit(struct cpufreq_policy *policy)
+{
+ unsigned int cpu;
+
+ for_each_cpu(cpu, policy->related_cpus) {
+ struct acpi_processor *pr = per_cpu(processors, cpu);
+
+ if (pr)
+ freq_qos_remove_request(&pr->thermal_req);
+ }
+}
+#else /* ! CONFIG_CPU_FREQ */
+static int cpufreq_get_max_state(unsigned int cpu)
+{
+ return 0;
+}
+
+static int cpufreq_get_cur_state(unsigned int cpu)
+{
+ return 0;
+}
+
+static int cpufreq_set_cur_state(unsigned int cpu, int state)
+{
+ return 0;
+}
+
+#endif
+
+/* thermal cooling device callbacks */
+static int acpi_processor_max_state(struct acpi_processor *pr)
+{
+ int max_state = 0;
+
+ /*
+ * There exists four states according to
+ * cpufreq_thermal_reduction_pctg. 0, 1, 2, 3
+ */
+ max_state += cpufreq_get_max_state(pr->id);
+ if (pr->flags.throttling)
+ max_state += (pr->throttling.state_count -1);
+
+ return max_state;
+}
+static int
+processor_get_max_state(struct thermal_cooling_device *cdev,
+ unsigned long *state)
+{
+ struct acpi_device *device = cdev->devdata;
+ struct acpi_processor *pr;
+
+ if (!device)
+ return -EINVAL;
+
+ pr = acpi_driver_data(device);
+ if (!pr)
+ return -EINVAL;
+
+ *state = acpi_processor_max_state(pr);
+ return 0;
+}
+
+static int
+processor_get_cur_state(struct thermal_cooling_device *cdev,
+ unsigned long *cur_state)
+{
+ struct acpi_device *device = cdev->devdata;
+ struct acpi_processor *pr;
+
+ if (!device)
+ return -EINVAL;
+
+ pr = acpi_driver_data(device);
+ if (!pr)
+ return -EINVAL;
+
+ *cur_state = cpufreq_get_cur_state(pr->id);
+ if (pr->flags.throttling)
+ *cur_state += pr->throttling.state;
+ return 0;
+}
+
+static int
+processor_set_cur_state(struct thermal_cooling_device *cdev,
+ unsigned long state)
+{
+ struct acpi_device *device = cdev->devdata;
+ struct acpi_processor *pr;
+ int result = 0;
+ int max_pstate;
+
+ if (!device)
+ return -EINVAL;
+
+ pr = acpi_driver_data(device);
+ if (!pr)
+ return -EINVAL;
+
+ max_pstate = cpufreq_get_max_state(pr->id);
+
+ if (state > acpi_processor_max_state(pr))
+ return -EINVAL;
+
+ if (state <= max_pstate) {
+ if (pr->flags.throttling && pr->throttling.state)
+ result = acpi_processor_set_throttling(pr, 0, false);
+ cpufreq_set_cur_state(pr->id, state);
+ } else {
+ cpufreq_set_cur_state(pr->id, max_pstate);
+ result = acpi_processor_set_throttling(pr,
+ state - max_pstate, false);
+ }
+ return result;
+}
+
+const struct thermal_cooling_device_ops processor_cooling_ops = {
+ .get_max_state = processor_get_max_state,
+ .get_cur_state = processor_get_cur_state,
+ .set_cur_state = processor_set_cur_state,
+};
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