Merge branch 'acpi-processor'

* acpi-processor:
  ACPI / CPPC: Fix potential memory leak
  ACPI / CPPC: signedness bug in register_pcc_channel()
  ACPI: Allow selection of the ACPI processor driver for ARM64
  CPPC: Probe for CPPC tables for each ACPI Processor object
  ACPI: Add weak routines for ACPI CPU Hotplug
  ACPI / CPPC: Add a CPUFreq driver for use with CPPC
  ACPI: Introduce CPU performance controls using CPPC

drivers/acpi/Kconfig

@@ -206,11 +206,25 @@ config ACPI_PROCESSOR_IDLE
 	bool
 	select CPU_IDLE
 
+config ACPI_CPPC_LIB
+	bool
+	depends on ACPI_PROCESSOR
+	depends on !ACPI_CPU_FREQ_PSS
+	select MAILBOX
+	select PCC
+	help
+	  If this option is enabled, this file implements common functionality
+	  to parse CPPC tables as described in the ACPI 5.1+ spec. The
+	  routines implemented are meant to be used by other
+	  drivers to control CPU performance using CPPC semantics.
+	  If your platform does not support CPPC in firmware,
+	  leave this option disabled.
+
 config ACPI_PROCESSOR
 	tristate "Processor"
-	depends on X86 || IA64
-	select ACPI_PROCESSOR_IDLE
-	select ACPI_CPU_FREQ_PSS
+	depends on X86 || IA64 || ARM64
+	select ACPI_PROCESSOR_IDLE if X86 || IA64
+	select ACPI_CPU_FREQ_PSS if X86 || IA64
 	default y
 	help
 	  This driver adds support for the ACPI Processor package. It is required

drivers/acpi/Makefile

@@ -78,6 +78,7 @@ obj-$(CONFIG_ACPI_HED)		+= hed.o
 obj-$(CONFIG_ACPI_EC_DEBUGFS)	+= ec_sys.o
 obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o
 obj-$(CONFIG_ACPI_BGRT)		+= bgrt.o
+obj-$(CONFIG_ACPI_CPPC_LIB)	+= cppc_acpi.o
 
 # processor has its own "processor." module_param namespace
 processor-y			:= processor_driver.o

drivers/acpi/acpi_processor.c

@@ -164,6 +164,24 @@ static int acpi_processor_errata(void)
    -------------------------------------------------------------------------- */
 
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
+int __weak acpi_map_cpu(acpi_handle handle,
+		phys_cpuid_t physid, int *pcpu)
+{
+	return -ENODEV;
+}
+
+int __weak acpi_unmap_cpu(int cpu)
+{
+	return -ENODEV;
+}
+
+int __weak arch_register_cpu(int cpu)
+{
+	return -ENODEV;
+}
+
+void __weak arch_unregister_cpu(int cpu) {}
+
 static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 {
 	unsigned long long sta;

drivers/acpi/processor_driver.c

@@ -242,6 +242,10 @@ static int __acpi_processor_start(struct acpi_device *device)
 	if (pr->flags.need_hotplug_init)
 		return 0;
 
+	result = acpi_cppc_processor_probe(pr);
+	if (result)
+		return -ENODEV;
+
 	if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 		acpi_processor_power_init(pr);
 
@@ -287,6 +291,8 @@ static int acpi_processor_stop(struct device *dev)
 
 	acpi_pss_perf_exit(pr, device);
 
+	acpi_cppc_processor_exit(pr);
+
 	return 0;
 }
 

drivers/cpufreq/Kconfig.arm

@@ -227,3 +227,20 @@ config ARM_PXA2xx_CPUFREQ
 	  This add the CPUFreq driver support for Intel PXA2xx SOCs.
 
 	  If in doubt, say N.
+
+config ACPI_CPPC_CPUFREQ
+	tristate "CPUFreq driver based on the ACPI CPPC spec"
+	depends on ACPI
+	select ACPI_CPPC_LIB
+	default n
+	help
+	  This adds a CPUFreq driver which uses CPPC methods
+	  as described in the ACPIv5.1 spec. CPPC stands for
+	  Collaborative Processor Performance Controls. It
+	  is based on an abstract continuous scale of CPU
+	  performance values which allows the remote power
+	  processor to flexibly optimize for power and
+	  performance. CPPC relies on power management firmware
+	  support for its operation.
+
+	  If in doubt, say N.

drivers/cpufreq/Makefile

@@ -76,6 +76,8 @@ obj-$(CONFIG_ARM_SPEAR_CPUFREQ)		+= spear-cpufreq.o
 obj-$(CONFIG_ARM_TEGRA20_CPUFREQ)	+= tegra20-cpufreq.o
 obj-$(CONFIG_ARM_TEGRA124_CPUFREQ)	+= tegra124-cpufreq.o
 obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ)	+= vexpress-spc-cpufreq.o
+obj-$(CONFIG_ACPI_CPPC_CPUFREQ) += cppc_cpufreq.o
+
 
 ##################################################################################
 # PowerPC platform drivers

drivers/cpufreq/cppc_cpufreq.c

+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#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/vmalloc.h>
+
+#include <acpi/cppc_acpi.h>
+
+/*
+ * 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 cpudata **all_cpu_data;
+
+static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
+		unsigned int target_freq,
+		unsigned int relation)
+{
+	struct cpudata *cpu;
+	struct cpufreq_freqs freqs;
+	int ret = 0;
+
+	cpu = all_cpu_data[policy->cpu];
+
+	cpu->perf_ctrls.desired_perf = target_freq;
+	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 *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 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);
+}
+
+static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+	struct 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;
+	}
+
+	policy->min = cpu->perf_caps.lowest_perf;
+	policy->max = cpu->perf_caps.highest_perf;
+	policy->cpuinfo.min_freq = policy->min;
+	policy->cpuinfo.max_freq = policy->max;
+
+	if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
+		cpumask_copy(policy->cpus, cpu->shared_cpu_map);
+	else {
+		/* Support only SW_ANY for now. */
+		pr_debug("Unsupported CPU co-ord type\n");
+		return -EFAULT;
+	}
+
+	cpumask_set_cpu(policy->cpu, policy->cpus);
+	cpu->cur_policy = policy;
+
+	/* Set policy->cur to max now. The governors will adjust later. */
+	policy->cur = 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 struct cpufreq_driver cppc_cpufreq_driver = {
+	.flags = CPUFREQ_CONST_LOOPS,
+	.verify = cppc_verify_policy,
+	.target = cppc_cpufreq_set_target,
+	.init = cppc_cpufreq_cpu_init,
+	.stop_cpu = cppc_cpufreq_stop_cpu,
+	.name = "cppc_cpufreq",
+};
+
+static int __init cppc_cpufreq_init(void)
+{
+	int i, ret = 0;
+	struct cpudata *cpu;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	all_cpu_data = kzalloc(sizeof(void *) * num_possible_cpus(), GFP_KERNEL);
+	if (!all_cpu_data)
+		return -ENOMEM;
+
+	for_each_possible_cpu(i) {
+		all_cpu_data[i] = kzalloc(sizeof(struct 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;
+	}
+
+	ret = cpufreq_register_driver(&cppc_cpufreq_driver);
+	if (ret)
+		goto out;
+
+	return ret;
+
+out:
+	for_each_possible_cpu(i)
+		if (all_cpu_data[i])
+			kfree(all_cpu_data[i]);
+
+	kfree(all_cpu_data);
+	return -ENODEV;
+}
+
+late_initcall(cppc_cpufreq_init);

include/acpi/cppc_acpi.h

+/*
+ * CPPC (Collaborative Processor Performance Control) methods used
+ * by CPUfreq drivers.
+ *
+ * (C) Copyright 2014, 2015 Linaro Ltd.
+ * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#ifndef _CPPC_ACPI_H
+#define _CPPC_ACPI_H
+
+#include <linux/acpi.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox_client.h>
+#include <linux/types.h>
+
+#include <acpi/processor.h>
+
+/* Only support CPPCv2 for now. */
+#define CPPC_NUM_ENT	21
+#define CPPC_REV	2
+
+#define PCC_CMD_COMPLETE 1
+#define MAX_CPC_REG_ENT 19
+
+/* CPPC specific PCC commands. */
+#define	CMD_READ 0
+#define	CMD_WRITE 1
+
+/* Each register has the folowing format. */
+struct cpc_reg {
+	u8 descriptor;
+	u16 length;
+	u8 space_id;
+	u8 bit_width;
+	u8 bit_offset;
+	u8 access_width;
+	u64 __iomem address;
+} __packed;
+
+/*
+ * Each entry in the CPC table is either
+ * of type ACPI_TYPE_BUFFER or
+ * ACPI_TYPE_INTEGER.
+ */
+struct cpc_register_resource {
+	acpi_object_type type;
+	union {
+		struct cpc_reg reg;
+		u64 int_value;
+	} cpc_entry;
+};
+
+/* Container to hold the CPC details for each CPU */
+struct cpc_desc {
+	int num_entries;
+	int version;
+	int cpu_id;
+	struct cpc_register_resource cpc_regs[MAX_CPC_REG_ENT];
+	struct acpi_psd_package domain_info;
+};
+
+/* These are indexes into the per-cpu cpc_regs[]. Order is important. */
+enum cppc_regs {
+	HIGHEST_PERF,
+	NOMINAL_PERF,
+	LOW_NON_LINEAR_PERF,
+	LOWEST_PERF,
+	GUARANTEED_PERF,
+	DESIRED_PERF,
+	MIN_PERF,
+	MAX_PERF,
+	PERF_REDUC_TOLERANCE,
+	TIME_WINDOW,
+	CTR_WRAP_TIME,
+	REFERENCE_CTR,
+	DELIVERED_CTR,
+	PERF_LIMITED,
+	ENABLE,
+	AUTO_SEL_ENABLE,
+	AUTO_ACT_WINDOW,
+	ENERGY_PERF,
+	REFERENCE_PERF,
+};
+
+/*
+ * Categorization of registers as described
+ * in the ACPI v.5.1 spec.
+ * XXX: Only filling up ones which are used by governors
+ * today.
+ */
+struct cppc_perf_caps {
+	u32 highest_perf;
+	u32 nominal_perf;
+	u32 reference_perf;
+	u32 lowest_perf;
+};
+
+struct cppc_perf_ctrls {
+	u32 max_perf;
+	u32 min_perf;
+	u32 desired_perf;
+};
+
+struct cppc_perf_fb_ctrs {
+	u64 reference;
+	u64 prev_reference;
+	u64 delivered;
+	u64 prev_delivered;
+};
+
+/* Per CPU container for runtime CPPC management. */
+struct cpudata {
+	int cpu;
+	struct cppc_perf_caps perf_caps;
+	struct cppc_perf_ctrls perf_ctrls;
+	struct cppc_perf_fb_ctrs perf_fb_ctrs;
+	struct cpufreq_policy *cur_policy;
+	unsigned int shared_type;
+	cpumask_var_t shared_cpu_map;
+};
+
+extern int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs);
+extern int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls);
+extern int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps);
+extern int acpi_get_psd_map(struct cpudata **);
+
+/* Methods to interact with the PCC mailbox controller. */
+extern struct mbox_chan *
+	pcc_mbox_request_channel(struct mbox_client *, unsigned int);
+extern int mbox_send_message(struct mbox_chan *chan, void *mssg);
+
+#endif /* _CPPC_ACPI_H*/

include/acpi/processor.h

@@ -311,6 +311,20 @@ phys_cpuid_t acpi_get_phys_id(acpi_handle, int type, u32 acpi_id);
 int acpi_map_cpuid(phys_cpuid_t phys_id, u32 acpi_id);
 int acpi_get_cpuid(acpi_handle, int type, u32 acpi_id);
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+extern int acpi_cppc_processor_probe(struct acpi_processor *pr);
+extern void acpi_cppc_processor_exit(struct acpi_processor *pr);
+#else
+static inline int acpi_cppc_processor_probe(struct acpi_processor *pr)
+{
+	return 0;
+}
+static inline void acpi_cppc_processor_exit(struct acpi_processor *pr)
+{
+	return;
+}
+#endif	/* CONFIG_ACPI_CPPC_LIB */
+
 /* in processor_pdc.c */
 void acpi_processor_set_pdc(acpi_handle handle);