cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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evxfregn.c (6485B)


      1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
      2/******************************************************************************
      3 *
      4 * Module Name: evxfregn - External Interfaces, ACPI Operation Regions and
      5 *                         Address Spaces.
      6 *
      7 * Copyright (C) 2000 - 2022, Intel Corp.
      8 *
      9 *****************************************************************************/
     10
     11#define EXPORT_ACPI_INTERFACES
     12
     13#include <acpi/acpi.h>
     14#include "accommon.h"
     15#include "acnamesp.h"
     16#include "acevents.h"
     17
     18#define _COMPONENT          ACPI_EVENTS
     19ACPI_MODULE_NAME("evxfregn")
     20
     21/*******************************************************************************
     22 *
     23 * FUNCTION:    acpi_install_address_space_handler
     24 *
     25 * PARAMETERS:  device          - Handle for the device
     26 *              space_id        - The address space ID
     27 *              handler         - Address of the handler
     28 *              setup           - Address of the setup function
     29 *              context         - Value passed to the handler on each access
     30 *
     31 * RETURN:      Status
     32 *
     33 * DESCRIPTION: Install a handler for all op_regions of a given space_id.
     34 *
     35 * NOTE: This function should only be called after acpi_enable_subsystem has
     36 * been called. This is because any _REG methods associated with the Space ID
     37 * are executed here, and these methods can only be safely executed after
     38 * the default handlers have been installed and the hardware has been
     39 * initialized (via acpi_enable_subsystem.)
     40 *
     41 ******************************************************************************/
     42acpi_status
     43acpi_install_address_space_handler(acpi_handle device,
     44				   acpi_adr_space_type space_id,
     45				   acpi_adr_space_handler handler,
     46				   acpi_adr_space_setup setup, void *context)
     47{
     48	struct acpi_namespace_node *node;
     49	acpi_status status;
     50
     51	ACPI_FUNCTION_TRACE(acpi_install_address_space_handler);
     52
     53	/* Parameter validation */
     54
     55	if (!device) {
     56		return_ACPI_STATUS(AE_BAD_PARAMETER);
     57	}
     58
     59	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
     60	if (ACPI_FAILURE(status)) {
     61		return_ACPI_STATUS(status);
     62	}
     63
     64	/* Convert and validate the device handle */
     65
     66	node = acpi_ns_validate_handle(device);
     67	if (!node) {
     68		status = AE_BAD_PARAMETER;
     69		goto unlock_and_exit;
     70	}
     71
     72	/* Install the handler for all Regions for this Space ID */
     73
     74	status =
     75	    acpi_ev_install_space_handler(node, space_id, handler, setup,
     76					  context);
     77	if (ACPI_FAILURE(status)) {
     78		goto unlock_and_exit;
     79	}
     80
     81	/* Run all _REG methods for this address space */
     82
     83	acpi_ev_execute_reg_methods(node, space_id, ACPI_REG_CONNECT);
     84
     85unlock_and_exit:
     86	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
     87	return_ACPI_STATUS(status);
     88}
     89
     90ACPI_EXPORT_SYMBOL(acpi_install_address_space_handler)
     91
     92/*******************************************************************************
     93 *
     94 * FUNCTION:    acpi_remove_address_space_handler
     95 *
     96 * PARAMETERS:  device          - Handle for the device
     97 *              space_id        - The address space ID
     98 *              handler         - Address of the handler
     99 *
    100 * RETURN:      Status
    101 *
    102 * DESCRIPTION: Remove a previously installed handler.
    103 *
    104 ******************************************************************************/
    105acpi_status
    106acpi_remove_address_space_handler(acpi_handle device,
    107				  acpi_adr_space_type space_id,
    108				  acpi_adr_space_handler handler)
    109{
    110	union acpi_operand_object *obj_desc;
    111	union acpi_operand_object *handler_obj;
    112	union acpi_operand_object *region_obj;
    113	union acpi_operand_object **last_obj_ptr;
    114	struct acpi_namespace_node *node;
    115	acpi_status status;
    116
    117	ACPI_FUNCTION_TRACE(acpi_remove_address_space_handler);
    118
    119	/* Parameter validation */
    120
    121	if (!device) {
    122		return_ACPI_STATUS(AE_BAD_PARAMETER);
    123	}
    124
    125	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
    126	if (ACPI_FAILURE(status)) {
    127		return_ACPI_STATUS(status);
    128	}
    129
    130	/* Convert and validate the device handle */
    131
    132	node = acpi_ns_validate_handle(device);
    133	if (!node ||
    134	    ((node->type != ACPI_TYPE_DEVICE) &&
    135	     (node->type != ACPI_TYPE_PROCESSOR) &&
    136	     (node->type != ACPI_TYPE_THERMAL) &&
    137	     (node != acpi_gbl_root_node))) {
    138		status = AE_BAD_PARAMETER;
    139		goto unlock_and_exit;
    140	}
    141
    142	/* Make sure the internal object exists */
    143
    144	obj_desc = acpi_ns_get_attached_object(node);
    145	if (!obj_desc) {
    146		status = AE_NOT_EXIST;
    147		goto unlock_and_exit;
    148	}
    149
    150	/* Find the address handler the user requested */
    151
    152	handler_obj = obj_desc->common_notify.handler;
    153	last_obj_ptr = &obj_desc->common_notify.handler;
    154	while (handler_obj) {
    155
    156		/* We have a handler, see if user requested this one */
    157
    158		if (handler_obj->address_space.space_id == space_id) {
    159
    160			/* Handler must be the same as the installed handler */
    161
    162			if (handler_obj->address_space.handler != handler) {
    163				status = AE_BAD_PARAMETER;
    164				goto unlock_and_exit;
    165			}
    166
    167			/* Matched space_id, first dereference this in the Regions */
    168
    169			ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
    170					  "Removing address handler %p(%p) for region %s "
    171					  "on Device %p(%p)\n",
    172					  handler_obj, handler,
    173					  acpi_ut_get_region_name(space_id),
    174					  node, obj_desc));
    175
    176			region_obj = handler_obj->address_space.region_list;
    177
    178			/* Walk the handler's region list */
    179
    180			while (region_obj) {
    181				/*
    182				 * First disassociate the handler from the region.
    183				 *
    184				 * NOTE: this doesn't mean that the region goes away
    185				 * The region is just inaccessible as indicated to
    186				 * the _REG method
    187				 */
    188				acpi_ev_detach_region(region_obj, TRUE);
    189
    190				/*
    191				 * Walk the list: Just grab the head because the
    192				 * detach_region removed the previous head.
    193				 */
    194				region_obj =
    195				    handler_obj->address_space.region_list;
    196			}
    197
    198			/* Remove this Handler object from the list */
    199
    200			*last_obj_ptr = handler_obj->address_space.next;
    201
    202			/* Now we can delete the handler object */
    203
    204			acpi_os_release_mutex(handler_obj->address_space.
    205					      context_mutex);
    206			acpi_ut_remove_reference(handler_obj);
    207			goto unlock_and_exit;
    208		}
    209
    210		/* Walk the linked list of handlers */
    211
    212		last_obj_ptr = &handler_obj->address_space.next;
    213		handler_obj = handler_obj->address_space.next;
    214	}
    215
    216	/* The handler does not exist */
    217
    218	ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
    219			  "Unable to remove address handler %p for %s(%X), DevNode %p, obj %p\n",
    220			  handler, acpi_ut_get_region_name(space_id), space_id,
    221			  node, obj_desc));
    222
    223	status = AE_NOT_EXIST;
    224
    225unlock_and_exit:
    226	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
    227	return_ACPI_STATUS(status);
    228}
    229
    230ACPI_EXPORT_SYMBOL(acpi_remove_address_space_handler)