/*
 * 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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright 2019 Joyent, Inc.
 */

#ifndef _SYS_MACHPRIVREGS_H
#define _SYS_MACHPRIVREGS_H

/*
 * Platform dependent instruction sequences for manipulating
 * privileged state
 */

#ifdef __cplusplus
extern "C" {
#endif

#define ASSERT_UPCALL_MASK_IS_SET               /* empty */

/*
 * CLI and STI
 */

#define CLI(r)                  \
        cli

#define STI                     \
        sti

/*
 * Used to re-enable interrupts in the body of exception handlers
 */

#if defined(__amd64)

#define ENABLE_INTR_FLAGS               \
        pushq   $F_ON;                  \
        popfq

#elif defined(__i386)

#define ENABLE_INTR_FLAGS               \
        pushl   $F_ON;                  \
        popfl

#endif  /* __i386 */

/*
 * IRET and SWAPGS
 */
#if defined(__amd64)

#define IRET    iretq
#define SYSRETQ sysretq
#define SYSRETL sysretl
#define SWAPGS  swapgs

/*
 * As of GNU binutils 2.37, the assembler has split the 'sysexit' instruction
 * into 'sysexitl' and 'sysexitq'. Using a plain 'sysexit' is interpreted as
 * 'sysexitl' but comes with a warning about the assumption being made. Since
 * all warnings are treated as errors in the kernel build, this results in a
 * build failure. Unfortunately the desired 'sysexitl' cannot be used since
 * older versions of the GNU assembler do not understand it.
 * The following macro emits the correct byte sequence for 'sysexitl' on this
 * platform.
 */
#define SYSEXITL .byte 0x0f, 0x35

#elif defined(__i386)

#define IRET    iret

#endif  /* __i386 */

#define XPV_TRAP_POP    /* empty */
#define XPV_TRAP_PUSH   /* empty */
#define CLEAN_CS        /* empty */


/*
 * Macros for saving the original segment registers and restoring them
 * for fast traps.
 */
#if defined(__amd64)

/*
 * Smaller versions of INTR_PUSH and INTR_POP for fast traps.
 * The following registers have been pushed onto the stack by
 * hardware at this point:
 *
 *      greg_t  r_rip;
 *      greg_t  r_cs;
 *      greg_t  r_rfl;
 *      greg_t  r_rsp;
 *      greg_t  r_ss;
 *
 * This handler is executed both by 32-bit and 64-bit applications.
 * 64-bit applications allow us to treat the set (%rdi, %rsi, %rdx,
 * %rcx, %r8, %r9, %r10, %r11, %rax) as volatile across function calls.
 * However, 32-bit applications only expect (%eax, %edx, %ecx) to be volatile
 * across a function call -- in particular, %esi and %edi MUST be saved!
 *
 * We could do this differently by making a FAST_INTR_PUSH32 for 32-bit
 * programs, and FAST_INTR_PUSH for 64-bit programs, but it doesn't seem
 * particularly worth it.
 */
#define FAST_INTR_PUSH                  \
        INTGATE_INIT_KERNEL_FLAGS;      \
        subq    $REGOFF_RIP, %rsp;      \
        movq    %rsi, REGOFF_RSI(%rsp); \
        movq    %rdi, REGOFF_RDI(%rsp); \
        swapgs

#define FAST_INTR_POP                   \
        swapgs;                         \
        movq    REGOFF_RSI(%rsp), %rsi; \
        movq    REGOFF_RDI(%rsp), %rdi; \
        addq    $REGOFF_RIP, %rsp

#define FAST_INTR_RETURN        call x86_md_clear; jmp tr_iret_user

#elif defined(__i386)

#define FAST_INTR_PUSH          \
        cld;                    \
        __SEGREGS_PUSH          \
        __SEGREGS_LOAD_KERNEL

#define FAST_INTR_POP           \
        __SEGREGS_POP

#define FAST_INTR_RETURN        iret

#endif  /* __i386 */

/*
 * Handling the CR0.TS bit for floating point handling.
 *
 * When the TS bit is *set*, attempts to touch the floating
 * point hardware will result in a #nm trap.
 */
#if defined(__amd64)

#define STTS(rtmp)              \
        movq    %cr0, rtmp;     \
        orq     $CR0_TS, rtmp;  \
        movq    rtmp, %cr0

#elif defined(__i386)

#define STTS(rtmp)              \
        movl    %cr0, rtmp;     \
        orl     $CR0_TS, rtmp;  \
        movl    rtmp, %cr0

#endif  /* __i386 */

#define CLTS                    \
        clts

#ifdef __cplusplus
}
#endif

#endif  /* _SYS_MACHPRIVREGS_H */