arch/arm64/kernel/acpi.c - arm/linux - Git at Google

 /*
  *  ARM64 Specific Low-Level ACPI Boot Support
  *
  *  Copyright (C) 2013-2014, Linaro Ltd.
  *	Author: Al Stone <al.stone@linaro.org>
  *	Author: Graeme Gregory <graeme.gregory@linaro.org>
  *	Author: Hanjun Guo <hanjun.guo@linaro.org>
  *	Author: Tomasz Nowicki <tomasz.nowicki@linaro.org>
  *	Author: Naresh Bhat <naresh.bhat@linaro.org>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2 as
  *  published by the Free Software Foundation.
  */

 #define pr_fmt(fmt) "ACPI: " fmt

 #include <linux/acpi.h>
 #include <linux/bootmem.h>
 #include <linux/cpumask.h>
 #include <linux/init.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
 #include <linux/memblock.h>
 #include <linux/of_fdt.h>
 #include <linux/smp.h>

 #include <asm/cputype.h>
 #include <asm/cpu_ops.h>
 #include <asm/smp_plat.h>

 int acpi_noirq = 1;		/* skip ACPI IRQ initialization */
 int acpi_disabled = 1;
 EXPORT_SYMBOL(acpi_disabled);

 int acpi_pci_disabled = 1;	/* skip ACPI PCI scan and IRQ initialization */
 EXPORT_SYMBOL(acpi_pci_disabled);

 /* Processors with enabled flag and sane MPIDR */
 static int enabled_cpus;

 /* Boot CPU is valid or not in MADT */
 static bool bootcpu_valid  __initdata;

 static bool param_acpi_off __initdata;
 static bool param_acpi_force __initdata;

 static int __init parse_acpi(char *arg)
 {
 	if (!arg)
 		return -EINVAL;

 	/* "acpi=off" disables both ACPI table parsing and interpreter */
 	if (strcmp(arg, "off") == 0)
 		param_acpi_off = true;
 	else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
 		param_acpi_force = true;
 	else
 		return -EINVAL;	/* Core will print when we return error */

 	return 0;
 }
 early_param("acpi", parse_acpi);

 static int __init dt_scan_depth1_nodes(unsigned long node,
 				       const char *uname, int depth,
 				       void *data)
 {
 	/*
 	 * Return 1 as soon as we encounter a node at depth 1 that is
 	 * not the /chosen node.
 	 */
 	if (depth == 1 && (strcmp(uname, "chosen") != 0))
 		return 1;
 	return 0;
 }

 /*
  * __acpi_map_table() will be called before page_init(), so early_ioremap()
  * or early_memremap() should be called here to for ACPI table mapping.
  */
 char *__init __acpi_map_table(unsigned long phys, unsigned long size)
 {
 	if (!size)
 		return NULL;

 	return early_memremap(phys, size);
 }

 void __init __acpi_unmap_table(char *map, unsigned long size)
 {
 	if (!map || !size)
 		return;

 	early_memunmap(map, size);
 }

 /**
  * acpi_map_gic_cpu_interface - generates a logical cpu number
  * and map to MPIDR represented by GICC structure
  * @mpidr: CPU's hardware id to register, MPIDR represented in MADT
  * @enabled: this cpu is enabled or not
  *
  * Returns the logical cpu number which maps to MPIDR
  */
 static int __init acpi_map_gic_cpu_interface(u64 mpidr, u8 enabled)
 {
 	int i;

 	if (mpidr == INVALID_HWID) {
 		pr_info("Skip MADT cpu entry with invalid MPIDR\n");
 		return -EINVAL;
 	}

 	total_cpus++;
 	if (!enabled)
 		return -EINVAL;

 	if (enabled_cpus >=  NR_CPUS) {
 		pr_warn("NR_CPUS limit of %d reached, Processor %d/0x%llx ignored.\n",
 			NR_CPUS, total_cpus, mpidr);
 		return -EINVAL;
 	}

 	/* Check if GICC structure of boot CPU is available in the MADT */
 	if (cpu_logical_map(0) == mpidr) {
 		if (bootcpu_valid) {
 			pr_err("Firmware bug, duplicate CPU MPIDR: 0x%llx in MADT\n",
 			       mpidr);
 			return -EINVAL;
 		}

 		bootcpu_valid = true;
 	}

 	/*
 	 * Duplicate MPIDRs are a recipe for disaster. Scan
 	 * all initialized entries and check for
 	 * duplicates. If any is found just ignore the CPU.
 	 */
 	for (i = 1; i < enabled_cpus; i++) {
 		if (cpu_logical_map(i) == mpidr) {
 			pr_err("Firmware bug, duplicate CPU MPIDR: 0x%llx in MADT\n",
 			       mpidr);
 			return -EINVAL;
 		}
 	}

 	if (!acpi_psci_present())
 		return -EOPNOTSUPP;

 	cpu_ops[enabled_cpus] = cpu_get_ops("psci");
 	/* CPU 0 was already initialized */
 	if (enabled_cpus) {
 		if (!cpu_ops[enabled_cpus])
 			return -EINVAL;

 		if (cpu_ops[enabled_cpus]->cpu_init(NULL, enabled_cpus))
 			return -EOPNOTSUPP;

 		/* map the logical cpu id to cpu MPIDR */
 		cpu_logical_map(enabled_cpus) = mpidr;
 	}

 	enabled_cpus++;
 	return enabled_cpus;
 }

 static int __init
 acpi_parse_gic_cpu_interface(struct acpi_subtable_header *header,
 				const unsigned long end)
 {
 	struct acpi_madt_generic_interrupt *processor;

 	processor = (struct acpi_madt_generic_interrupt *)header;

 	if (BAD_MADT_ENTRY(processor, end))
 		return -EINVAL;

 	acpi_table_print_madt_entry(header);

 	acpi_map_gic_cpu_interface(processor->arm_mpidr & MPIDR_HWID_BITMASK,
 		processor->flags & ACPI_MADT_ENABLED);

 	return 0;
 }

 /* Parse GIC cpu interface entries in MADT for SMP init */
 void __init acpi_init_cpus(void)
 {
 	int count, i;

 	/*
 	 * do a partial walk of MADT to determine how many CPUs
 	 * we have including disabled CPUs, and get information
 	 * we need for SMP init
 	 */
 	count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
 			acpi_parse_gic_cpu_interface, 0);

 	if (!count) {
 		pr_err("No GIC CPU interface entries present\n");
 		return;
 	} else if (count < 0) {
 		pr_err("Error parsing GIC CPU interface entry\n");
 		return;
 	}

 	if (!bootcpu_valid) {
 		pr_err("MADT missing boot CPU MPIDR, not enabling secondaries\n");
 		return;
 	}

 	for (i = 0; i < enabled_cpus; i++)
 		set_cpu_possible(i, true);

 	/* Make boot-up look pretty */
 	pr_info("%d CPUs enabled, %d CPUs total\n", enabled_cpus, total_cpus);
 }

 static int __init acpi_parse_fadt(struct acpi_table_header *table)
 {
 	struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table;

 	/*
 	 * Revision in table header is the FADT Major revision, and there
 	 * is a minor revision of FADT which was introduced by ACPI 5.1,
 	 * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
 	 * boot protocol configuration data, or we will disable ACPI.
 	 */
 	if (table->revision > 5 ||
 	    (table->revision == 5 && fadt->minor_revision >= 1)) {
 		/*
 		 * ACPI 5.1 only has two explicit methods to boot up SMP,
 		 * PSCI and Parking protocol, but the Parking protocol is
 		 * only specified for ARMv7 now, so make PSCI as the only
 		 * way for the SMP boot protocol before some updates for
 		 * the Parking protocol spec.
 		 */
 		if (acpi_psci_present())
 			return 0;

 		pr_warn("No PSCI support, will not bring up secondary CPUs\n");
 		return -EOPNOTSUPP;
 	}

 	pr_warn("Unsupported FADT revision %d.%d, should be 5.1+, will disable ACPI\n",
 		table->revision, fadt->minor_revision);
 	disable_acpi();

 	return -EINVAL;
 }

 /*
  * acpi_boot_table_init() called from setup_arch(), always.
  *	1. find RSDP and get its address, and then find XSDT
  *	2. extract all tables and checksums them all
  *	3. check ACPI FADT revision
  *
  * We can parse ACPI boot-time tables such as MADT after
  * this function is called.
  */
 void __init acpi_boot_table_init(void)
 {
 	/*
 	 * Enable ACPI instead of device tree unless
 	 * - ACPI has been disabled explicitly (acpi=off), or
 	 * - the device tree is not empty (it has more than just a /chosen node)
 	 *   and ACPI has not been force enabled (acpi=force)
 	 */
 	if (param_acpi_off ||
 	    (!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
 		return;

 	enable_acpi();

 	/* Initialize the ACPI boot-time table parser. */
 	if (acpi_table_init()) {
 		disable_acpi();
 		return;
 	}

 	if (acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt)) {
 		/* disable ACPI if no FADT is found */
 		disable_acpi();
 		pr_err("Can't find FADT\n");
 	}
 }
	/*
	* ARM64 Specific Low-Level ACPI Boot Support
	*
	* Copyright (C) 2013-2014, Linaro Ltd.
	* Author: Al Stone <al.stone@linaro.org>
	* Author: Graeme Gregory <graeme.gregory@linaro.org>
	* Author: Hanjun Guo <hanjun.guo@linaro.org>
	* Author: Tomasz Nowicki <tomasz.nowicki@linaro.org>
	* Author: Naresh Bhat <naresh.bhat@linaro.org>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#define pr_fmt(fmt) "ACPI: " fmt

	#include <linux/acpi.h>
	#include <linux/bootmem.h>
	#include <linux/cpumask.h>
	#include <linux/init.h>
	#include <linux/irq.h>
	#include <linux/irqdomain.h>
	#include <linux/memblock.h>
	#include <linux/of_fdt.h>
	#include <linux/smp.h>

	#include <asm/cputype.h>
	#include <asm/cpu_ops.h>
	#include <asm/smp_plat.h>

	int acpi_noirq = 1; /* skip ACPI IRQ initialization */
	int acpi_disabled = 1;
	EXPORT_SYMBOL(acpi_disabled);

	int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */
	EXPORT_SYMBOL(acpi_pci_disabled);

	/* Processors with enabled flag and sane MPIDR */
	static int enabled_cpus;

	/* Boot CPU is valid or not in MADT */
	static bool bootcpu_valid __initdata;

	static bool param_acpi_off __initdata;
	static bool param_acpi_force __initdata;

	static int __init parse_acpi(char *arg)
	{
	if (!arg)
	return -EINVAL;

	/* "acpi=off" disables both ACPI table parsing and interpreter */
	if (strcmp(arg, "off") == 0)
	param_acpi_off = true;
	else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
	param_acpi_force = true;
	else
	return -EINVAL; /* Core will print when we return error */

	return 0;
	}
	early_param("acpi", parse_acpi);

	static int __init dt_scan_depth1_nodes(unsigned long node,
	const char *uname, int depth,
	void *data)
	{
	/*
	* Return 1 as soon as we encounter a node at depth 1 that is
	* not the /chosen node.
	*/
	if (depth == 1 && (strcmp(uname, "chosen") != 0))
	return 1;
	return 0;
	}

	/*
	* __acpi_map_table() will be called before page_init(), so early_ioremap()
	* or early_memremap() should be called here to for ACPI table mapping.
	*/
	char *__init __acpi_map_table(unsigned long phys, unsigned long size)
	{
	if (!size)
	return NULL;

	return early_memremap(phys, size);
	}

	void __init __acpi_unmap_table(char *map, unsigned long size)
	{
	if (!map \|\| !size)
	return;

	early_memunmap(map, size);
	}

	/**
	* acpi_map_gic_cpu_interface - generates a logical cpu number
	* and map to MPIDR represented by GICC structure
	* @mpidr: CPU's hardware id to register, MPIDR represented in MADT
	* @enabled: this cpu is enabled or not
	*
	* Returns the logical cpu number which maps to MPIDR
	*/
	static int __init acpi_map_gic_cpu_interface(u64 mpidr, u8 enabled)
	{
	int i;

	if (mpidr == INVALID_HWID) {
	pr_info("Skip MADT cpu entry with invalid MPIDR\n");
	return -EINVAL;
	}

	total_cpus++;
	if (!enabled)
	return -EINVAL;

	if (enabled_cpus >= NR_CPUS) {
	pr_warn("NR_CPUS limit of %d reached, Processor %d/0x%llx ignored.\n",
	NR_CPUS, total_cpus, mpidr);
	return -EINVAL;
	}

	/* Check if GICC structure of boot CPU is available in the MADT */
	if (cpu_logical_map(0) == mpidr) {
	if (bootcpu_valid) {
	pr_err("Firmware bug, duplicate CPU MPIDR: 0x%llx in MADT\n",
	mpidr);
	return -EINVAL;
	}

	bootcpu_valid = true;
	}

	/*
	* Duplicate MPIDRs are a recipe for disaster. Scan
	* all initialized entries and check for
	* duplicates. If any is found just ignore the CPU.
	*/
	for (i = 1; i < enabled_cpus; i++) {
	if (cpu_logical_map(i) == mpidr) {
	pr_err("Firmware bug, duplicate CPU MPIDR: 0x%llx in MADT\n",
	mpidr);
	return -EINVAL;
	}
	}

	if (!acpi_psci_present())
	return -EOPNOTSUPP;

	cpu_ops[enabled_cpus] = cpu_get_ops("psci");
	/* CPU 0 was already initialized */
	if (enabled_cpus) {
	if (!cpu_ops[enabled_cpus])
	return -EINVAL;

	if (cpu_ops[enabled_cpus]->cpu_init(NULL, enabled_cpus))
	return -EOPNOTSUPP;

	/* map the logical cpu id to cpu MPIDR */
	cpu_logical_map(enabled_cpus) = mpidr;
	}

	enabled_cpus++;
	return enabled_cpus;
	}

	static int __init
	acpi_parse_gic_cpu_interface(struct acpi_subtable_header *header,
	const unsigned long end)
	{
	struct acpi_madt_generic_interrupt *processor;

	processor = (struct acpi_madt_generic_interrupt *)header;

	if (BAD_MADT_ENTRY(processor, end))
	return -EINVAL;

	acpi_table_print_madt_entry(header);

	acpi_map_gic_cpu_interface(processor->arm_mpidr & MPIDR_HWID_BITMASK,
	processor->flags & ACPI_MADT_ENABLED);

	return 0;
	}

	/* Parse GIC cpu interface entries in MADT for SMP init */
	void __init acpi_init_cpus(void)
	{
	int count, i;

	/*
	* do a partial walk of MADT to determine how many CPUs
	* we have including disabled CPUs, and get information
	* we need for SMP init
	*/
	count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
	acpi_parse_gic_cpu_interface, 0);

	if (!count) {
	pr_err("No GIC CPU interface entries present\n");
	return;
	} else if (count < 0) {
	pr_err("Error parsing GIC CPU interface entry\n");
	return;
	}

	if (!bootcpu_valid) {
	pr_err("MADT missing boot CPU MPIDR, not enabling secondaries\n");
	return;
	}

	for (i = 0; i < enabled_cpus; i++)
	set_cpu_possible(i, true);

	/* Make boot-up look pretty */
	pr_info("%d CPUs enabled, %d CPUs total\n", enabled_cpus, total_cpus);
	}

	static int __init acpi_parse_fadt(struct acpi_table_header *table)
	{
	struct acpi_table_fadt fadt = (struct acpi_table_fadt )table;

	/*
	* Revision in table header is the FADT Major revision, and there
	* is a minor revision of FADT which was introduced by ACPI 5.1,
	* we only deal with ACPI 5.1 or newer revision to get GIC and SMP
	* boot protocol configuration data, or we will disable ACPI.
	*/
	if (table->revision > 5 \|\|
	(table->revision == 5 && fadt->minor_revision >= 1)) {
	/*
	* ACPI 5.1 only has two explicit methods to boot up SMP,
	* PSCI and Parking protocol, but the Parking protocol is
	* only specified for ARMv7 now, so make PSCI as the only
	* way for the SMP boot protocol before some updates for
	* the Parking protocol spec.
	*/
	if (acpi_psci_present())
	return 0;

	pr_warn("No PSCI support, will not bring up secondary CPUs\n");
	return -EOPNOTSUPP;
	}

	pr_warn("Unsupported FADT revision %d.%d, should be 5.1+, will disable ACPI\n",
	table->revision, fadt->minor_revision);
	disable_acpi();

	return -EINVAL;
	}

	/*
	* acpi_boot_table_init() called from setup_arch(), always.
	* 1. find RSDP and get its address, and then find XSDT
	* 2. extract all tables and checksums them all
	* 3. check ACPI FADT revision
	*
	* We can parse ACPI boot-time tables such as MADT after
	* this function is called.
	*/
	void __init acpi_boot_table_init(void)
	{
	/*
	* Enable ACPI instead of device tree unless
	* - ACPI has been disabled explicitly (acpi=off), or
	* - the device tree is not empty (it has more than just a /chosen node)
	* and ACPI has not been force enabled (acpi=force)
	*/
	if (param_acpi_off \|\|
	(!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
	return;

	enable_acpi();

	/* Initialize the ACPI boot-time table parser. */
	if (acpi_table_init()) {
	disable_acpi();
	return;
	}

	if (acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt)) {
	/* disable ACPI if no FADT is found */
	disable_acpi();
	pr_err("Can't find FADT\n");
	}
	}