/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright 2019 Joyent, Inc.
 */

#include <sys/asm_linkage.h>
#include <sys/asm_misc.h>

/*
 * Implementation as specific by ACPI 3.0 specification
 * section 5.2.10.1
 *
 * Global Lock Structure within the FACS
 *
 * |-----------------------------------------------------------------------|
 * |  Field  | Bit Length | Bit Offset |           Description             |
 * |---------|------------|------------|-----------------------------------|
 * | Pending |     1      |     0      | Non-zero indicates that a request |
 * |         |            |            | for ownership of the global lock  |
 * |         |            |            | is pending.                       |
 * |---------|------------|------------|-----------------------------------|
 * | Owned   |     1      |     1      | Non-zero indicates that the Global|
 * |         |            |            | lock is owned.                    |
 * |---------|------------|------------|-----------------------------------|
 * | Reserved|     30     |     2      | Reserved for future use           |
 * |---------|------------|------------|-----------------------------------|
 */

/* Offset of GlobalLock element in FACS structure */
#define GlobalLock      0x10

        ENTRY(__acpi_acquire_global_lock)
        movq    $0xff, %rax             / error return if FACS is null
        orq     %rdi, %rdi              / %rdi contains pointer to FACS
        jz      1f
        leaq    GlobalLock(%rdi), %rdi  / make %rdi point at the lock
0:
        movl    (%rdi), %eax            / get current value of Global Lock
        movl    %eax, %edx
        andl    $0xFFFFFFFE, %edx       / Clear pending bit
        btsl    $1, %edx                / Check and set owner bit
        adcl    $0, %edx                / If owned, set pending bit
        lock
        cmpxchgl %edx, (%rdi)           / Attempt to set new value
        jnz     0b                      / If not set, try again
        cmpb    $3, %dl                 / Was it acquired or marked pending?
        sbbq    %rax, %rax              / acquired = -1, pending = 0
1:
        ret
        SET_SIZE(__acpi_acquire_global_lock)


        ENTRY(__acpi_release_global_lock)
        xorq    %rax, %rax      / error return if FACS is null
        orq     %rdi, %rdi      / %rdi contains pointer to FACS
        jz      1f
        leaq    GlobalLock(%rdi), %rdi  / make %rdi point at the lock
0:
        movl    (%rdi), %eax
        movl    %eax, %edx
        andl    $0xFFFFFFFC, %edx
        lock
        cmpxchgl %edx, (%rdi)
        jnz     0b
        andq    $1, %rax
1:
        ret
        SET_SIZE(__acpi_release_global_lock)


/*
 * execute WBINVD instruction
 */

        ENTRY(__acpi_wbinvd)
        wbinvd
        ret
        SET_SIZE(__acpi_wbinvd)