acpi/arm64: Add GTDT table parse driver (5f1ae4eb) · Commits · e / devices / android_kernel_fairphone_FP4

arch/arm64/Kconfig

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		@@ -2,6 +2,7 @@ config ARM64
		def_bool y
		select ACPI_CCA_REQUIRED if ACPI
		select ACPI_GENERIC_GSI if ACPI
		select ACPI_GTDT if ACPI
		select ACPI_REDUCED_HARDWARE_ONLY if ACPI
		select ACPI_MCFG if ACPI
		select ACPI_SPCR_TABLE if ACPI

drivers/acpi/arm64/Kconfig

+3 −0

Original line number	Diff line number	Diff line
		@@ -4,3 +4,6 @@

		config ACPI_IORT
		bool

		config ACPI_GTDT
		bool

drivers/acpi/arm64/Makefile

+1 −0

Original line number	Diff line number	Diff line
		obj-$(CONFIG_ACPI_IORT) += iort.o
		obj-$(CONFIG_ACPI_GTDT) += gtdt.o

drivers/acpi/arm64/gtdt.c

0 → 100644

+157 −0

Original line number	Diff line number	Diff line
		/*
		* ARM Specific GTDT table Support
		*
		* Copyright (C) 2016, Linaro Ltd.
		* Author: Daniel Lezcano <daniel.lezcano@linaro.org>
		* Fu Wei <fu.wei@linaro.org>
		* Hanjun Guo <hanjun.guo@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.
		*/

		#include <linux/acpi.h>
		#include <linux/init.h>
		#include <linux/kernel.h>

		#include <clocksource/arm_arch_timer.h>

		#undef pr_fmt
		#define pr_fmt(fmt) "ACPI GTDT: " fmt

		/**
		* struct acpi_gtdt_descriptor - Store the key info of GTDT for all functions
		* @gtdt: The pointer to the struct acpi_table_gtdt of GTDT table.
		* @gtdt_end: The pointer to the end of GTDT table.
		* @platform_timer: The pointer to the start of Platform Timer Structure
		*
		* The struct store the key info of GTDT table, it should be initialized by
		* acpi_gtdt_init.
		*/
		struct acpi_gtdt_descriptor {
		struct acpi_table_gtdt *gtdt;
		void *gtdt_end;
		void *platform_timer;
		};

		static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata;

		static int __init map_gt_gsi(u32 interrupt, u32 flags)
		{
		int trigger, polarity;

		trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
		: ACPI_LEVEL_SENSITIVE;

		polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
		: ACPI_ACTIVE_HIGH;

		return acpi_register_gsi(NULL, interrupt, trigger, polarity);
		}

		/**
		* acpi_gtdt_map_ppi() - Map the PPIs of per-cpu arch_timer.
		* @type: the type of PPI.
		*
		* Note: Secure state is not managed by the kernel on ARM64 systems.
		* So we only handle the non-secure timer PPIs,
		* ARCH_TIMER_PHYS_SECURE_PPI is treated as invalid type.
		*
		* Return: the mapped PPI value, 0 if error.
		*/
		int __init acpi_gtdt_map_ppi(int type)
		{
		struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;

		switch (type) {
		case ARCH_TIMER_PHYS_NONSECURE_PPI:
		return map_gt_gsi(gtdt->non_secure_el1_interrupt,
		gtdt->non_secure_el1_flags);
		case ARCH_TIMER_VIRT_PPI:
		return map_gt_gsi(gtdt->virtual_timer_interrupt,
		gtdt->virtual_timer_flags);

		case ARCH_TIMER_HYP_PPI:
		return map_gt_gsi(gtdt->non_secure_el2_interrupt,
		gtdt->non_secure_el2_flags);
		default:
		pr_err("Failed to map timer interrupt: invalid type.\n");
		}

		return 0;
		}

		/**
		* acpi_gtdt_c3stop() - Got c3stop info from GTDT according to the type of PPI.
		* @type: the type of PPI.
		*
		* Return: true if the timer HW state is lost when a CPU enters an idle state,
		* false otherwise
		*/
		bool __init acpi_gtdt_c3stop(int type)
		{
		struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;

		switch (type) {
		case ARCH_TIMER_PHYS_NONSECURE_PPI:
		return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);

		case ARCH_TIMER_VIRT_PPI:
		return !(gtdt->virtual_timer_flags & ACPI_GTDT_ALWAYS_ON);

		case ARCH_TIMER_HYP_PPI:
		return !(gtdt->non_secure_el2_flags & ACPI_GTDT_ALWAYS_ON);

		default:
		pr_err("Failed to get c3stop info: invalid type.\n");
		}

		return false;
		}

		/**
		* acpi_gtdt_init() - Get the info of GTDT table to prepare for further init.
		* @table: The pointer to GTDT table.
		* @platform_timer_count: It points to a integer variable which is used
		* for storing the number of platform timers.
		* This pointer could be NULL, if the caller
		* doesn't need this info.
		*
		* Return: 0 if success, -EINVAL if error.
		*/
		int __init acpi_gtdt_init(struct acpi_table_header *table,
		int *platform_timer_count)
		{
		void *platform_timer;
		struct acpi_table_gtdt *gtdt;

		gtdt = container_of(table, struct acpi_table_gtdt, header);
		acpi_gtdt_desc.gtdt = gtdt;
		acpi_gtdt_desc.gtdt_end = (void *)table + table->length;
		acpi_gtdt_desc.platform_timer = NULL;
		if (platform_timer_count)
		*platform_timer_count = 0;

		if (table->revision < 2) {
		pr_warn("Revision:%d doesn't support Platform Timers.\n",
		table->revision);
		return 0;
		}

		if (!gtdt->platform_timer_count) {
		pr_debug("No Platform Timer.\n");
		return 0;
		}

		platform_timer = (void *)gtdt + gtdt->platform_timer_offset;
		if (platform_timer < (void *)table + sizeof(struct acpi_table_gtdt)) {
		pr_err(FW_BUG "invalid timer data.\n");
		return -EINVAL;
		}
		acpi_gtdt_desc.platform_timer = platform_timer;
		if (platform_timer_count)
		*platform_timer_count = gtdt->platform_timer_count;

		return 0;
		}

include/linux/acpi.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -595,6 +595,12 @@ enum acpi_reconfig_event {
		int acpi_reconfig_notifier_register(struct notifier_block *nb);
		int acpi_reconfig_notifier_unregister(struct notifier_block *nb);

		#ifdef CONFIG_ACPI_GTDT
		int acpi_gtdt_init(struct acpi_table_header table, int platform_timer_count);
		int acpi_gtdt_map_ppi(int type);
		bool acpi_gtdt_c3stop(int type);
		#endif

		#else /* !CONFIG_ACPI */

		#define acpi_disabled 1