ACPI/ADXL: Add address translation interface using an ACPI DSM (4cf841e3) · Commits · 戴 / test

drivers/acpi/Kconfig

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		@@ -498,6 +498,9 @@ config ACPI_EXTLOG
		driver adds support for that functionality with corresponding
		tracepoint which carries that information to userspace.

		config ACPI_ADXL
		bool

		menuconfig PMIC_OPREGION
		bool "PMIC (Power Management Integrated Circuit) operation region support"
		help

drivers/acpi/Makefile

+3 −0

Original line number	Diff line number	Diff line
		@@ -61,6 +61,9 @@ acpi-$(CONFIG_ACPI_LPIT) += acpi_lpit.o
		acpi-$(CONFIG_ACPI_GENERIC_GSI) += irq.o
		acpi-$(CONFIG_ACPI_WATCHDOG) += acpi_watchdog.o

		# Address translation
		acpi-$(CONFIG_ACPI_ADXL) += acpi_adxl.o

		# These are (potentially) separate modules

		# IPMI may be used by other drivers, so it has to initialise before them

drivers/acpi/acpi_adxl.c

0 → 100644

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		// SPDX-License-Identifier: GPL-2.0
		/*
		* Address translation interface via ACPI DSM.
		* Copyright (C) 2018 Intel Corporation
		*
		* Specification for this interface is available at:
		*
		* https://cdrdv2.intel.com/v1/dl/getContent/603354
		*/

		#include <linux/acpi.h>
		#include <linux/adxl.h>

		#define ADXL_REVISION 0x1
		#define ADXL_IDX_GET_ADDR_PARAMS 0x1
		#define ADXL_IDX_FORWARD_TRANSLATE 0x2
		#define ACPI_ADXL_PATH "\\_SB.ADXL"

		/*
		* The specification doesn't provide a limit on how many
		* components are in a memory address. But since we allocate
		* memory based on the number the BIOS tells us, we should
		* defend against insane values.
		*/
		#define ADXL_MAX_COMPONENTS 500

		#undef pr_fmt
		#define pr_fmt(fmt) "ADXL: " fmt

		static acpi_handle handle;
		static union acpi_object *params;
		static const guid_t adxl_guid =
		GUID_INIT(0xAA3C050A, 0x7EA4, 0x4C1F,
		0xAF, 0xDA, 0x12, 0x67, 0xDF, 0xD3, 0xD4, 0x8D);

		static int adxl_count;
		static char **adxl_component_names;

		static union acpi_object *adxl_dsm(int cmd, union acpi_object argv[])
		{
		union acpi_object obj, o;

		obj = acpi_evaluate_dsm_typed(handle, &adxl_guid, ADXL_REVISION,
		cmd, argv, ACPI_TYPE_PACKAGE);
		if (!obj) {
		pr_info("DSM call failed for cmd=%d\n", cmd);
		return NULL;
		}

		if (obj->package.count != 2) {
		pr_info("Bad pkg count %d\n", obj->package.count);
		goto err;
		}

		o = obj->package.elements;
		if (o->type != ACPI_TYPE_INTEGER) {
		pr_info("Bad 1st element type %d\n", o->type);
		goto err;
		}
		if (o->integer.value) {
		pr_info("Bad ret val %llu\n", o->integer.value);
		goto err;
		}

		o = obj->package.elements + 1;
		if (o->type != ACPI_TYPE_PACKAGE) {
		pr_info("Bad 2nd element type %d\n", o->type);
		goto err;
		}
		return obj;

		err:
		ACPI_FREE(obj);
		return NULL;
		}

		/**
		* adxl_get_component_names - get list of memory component names
		* Returns NULL terminated list of string names
		*
		* Give the caller a pointer to the list of memory component names
		* e.g. { "SystemAddress", "ProcessorSocketId", "ChannelId", ... NULL }
		* Caller should count how many strings in order to allocate a buffer
		* for the return from adxl_decode().
		*/
		const char * const *adxl_get_component_names(void)
		{
		return (const char * const *)adxl_component_names;
		}
		EXPORT_SYMBOL_GPL(adxl_get_component_names);

		/**
		* adxl_decode - ask BIOS to decode a system address to memory address
		* @addr: the address to decode
		* @component_values: pointer to array of values for each component
		* Returns 0 on success, negative error code otherwise
		*
		* The index of each value returned in the array matches the index of
		* each component name returned by adxl_get_component_names().
		* Components that are not defined for this address translation (e.g.
		* mirror channel number for a non-mirrored address) are set to ~0ull.
		*/
		int adxl_decode(u64 addr, u64 component_values[])
		{
		union acpi_object argv4[2], results, r;
		int i, cnt;

		if (!adxl_component_names)
		return -EOPNOTSUPP;

		argv4[0].type = ACPI_TYPE_PACKAGE;
		argv4[0].package.count = 1;
		argv4[0].package.elements = &argv4[1];
		argv4[1].integer.type = ACPI_TYPE_INTEGER;
		argv4[1].integer.value = addr;

		results = adxl_dsm(ADXL_IDX_FORWARD_TRANSLATE, argv4);
		if (!results)
		return -EINVAL;

		r = results->package.elements + 1;
		cnt = r->package.count;
		if (cnt != adxl_count) {
		ACPI_FREE(results);
		return -EINVAL;
		}
		r = r->package.elements;

		for (i = 0; i < cnt; i++)
		component_values[i] = r[i].integer.value;

		ACPI_FREE(results);

		return 0;
		}
		EXPORT_SYMBOL_GPL(adxl_decode);

		static int __init adxl_init(void)
		{
		char *path = ACPI_ADXL_PATH;
		union acpi_object *p;
		acpi_status status;
		int i;

		status = acpi_get_handle(NULL, path, &handle);
		if (ACPI_FAILURE(status)) {
		pr_debug("No ACPI handle for path %s\n", path);
		return -ENODEV;
		}

		if (!acpi_has_method(handle, "_DSM")) {
		pr_info("No DSM method\n");
		return -ENODEV;
		}

		if (!acpi_check_dsm(handle, &adxl_guid, ADXL_REVISION,
		ADXL_IDX_GET_ADDR_PARAMS \|
		ADXL_IDX_FORWARD_TRANSLATE)) {
		pr_info("DSM method does not support forward translate\n");
		return -ENODEV;
		}

		params = adxl_dsm(ADXL_IDX_GET_ADDR_PARAMS, NULL);
		if (!params) {
		pr_info("Failed to get component names\n");
		return -ENODEV;
		}

		p = params->package.elements + 1;
		adxl_count = p->package.count;
		if (adxl_count > ADXL_MAX_COMPONENTS) {
		pr_info("Insane number of address component names %d\n", adxl_count);
		ACPI_FREE(params);
		return -ENODEV;
		}
		p = p->package.elements;

		/*
		* Allocate one extra for NULL termination.
		*/
		adxl_component_names = kcalloc(adxl_count + 1, sizeof(char *), GFP_KERNEL);
		if (!adxl_component_names) {
		ACPI_FREE(params);
		return -ENOMEM;
		}

		for (i = 0; i < adxl_count; i++)
		adxl_component_names[i] = p[i].string.pointer;

		return 0;
		}
		subsys_initcall(adxl_init);

include/linux/adxl.h

0 → 100644

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		/* SPDX-License-Identifier: GPL-2.0 */
		/*
		* Address translation interface via ACPI DSM.
		* Copyright (C) 2018 Intel Corporation
		*/

		#ifndef _LINUX_ADXL_H
		#define _LINUX_ADXL_H

		const char * const *adxl_get_component_names(void);
		int adxl_decode(u64 addr, u64 component_values[]);

		#endif /* _LINUX_ADXL_H */

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