/*
 * 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 (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2019 Joyent, Inc.
 */

/*
 * This is an assembly file that gets #include-ed into the brand-specific
 * assembly files (e.g. sn1_brand_asm.s) for Solaris-derived brands.
 * We can't make these into functions since in the trap context there's
 * no easy place to save the extra parameters that would be required, so
 * each brand module needs its own copy of this code.  We #include this and
 * use brand-specific #defines to replace the XXX_brand_... definitions.
 */

#include <sys/asm_linkage.h>
#include <sys/privregs.h>
#include <sys/segments.h>
#include "assym.h"
#include "brand_asm.h"

#ifdef _ASM     /* The remainder of this file is only for assembly files */

/*
 * syscall handler for 32-bit user processes:
 * See "64-BIT INTERPOSITION STACK" in brand_asm.h.
 * To 'return' to our user-space handler, we just need to place its address
 * into %rcx.  The original return address is passed back in SYSCALL_REG.
 */
ENTRY(XXX_brand_syscall32_callback)
        CALLBACK_PROLOGUE(XXX_emulation_table, SPD_HANDLER, SYSCALL_REG,
            SCR_REG, SCR_REGB);
        CALC_TABLE_ADDR(SCR_REG, SPD_HANDLER);
        mov     %rcx, SYSCALL_REG; /* save orig return addr in syscall_reg */
        mov     SCR_REG, %rcx;  /* place new return addr in %rcx */
        mov     %gs:CPU_RTMP_R15, SCR_REG; /* restore scratch register */
        call    x86_md_clear            /* Flush micro-arch state */
        mov     V_SSP(SP_REG), SP_REG   /* restore user stack pointer */
        jmp     nopop_sys_syscall32_swapgs_sysretl
9:
        retq
SET_SIZE(XXX_brand_syscall32_callback)

/*
 * syscall handler for 64-bit user processes:
 * See "64-BIT INTERPOSITION STACK" in brand_asm.h.
 * To 'return' to our user-space handler, we just need to place its address
 * into %rcx.  The original return address is passed back in SYSCALL_REG.
 */
ENTRY(XXX_brand_syscall_callback)
        CALLBACK_PROLOGUE(XXX_emulation_table, SPD_HANDLER, SYSCALL_REG,
            SCR_REG, SCR_REGB);
        CALC_TABLE_ADDR(SCR_REG, SPD_HANDLER);
        mov     %rcx, SYSCALL_REG; /* save orig return addr in syscall_reg */
        mov     SCR_REG, %rcx;  /* place new return addr in %rcx */
        mov     %gs:CPU_RTMP_R15, SCR_REG; /* restore scratch register */
        call    x86_md_clear            /* Flush micro-arch state */
        mov     V_SSP(SP_REG), SP_REG   /* restore user stack pointer */
        jmp     nopop_sys_syscall_swapgs_sysretq
9:
        retq
SET_SIZE(XXX_brand_syscall_callback)

/*
 * See "64-BIT INTERPOSITION STACK" in brand_asm.h.
 * To 'return' to our user-space handler, we just need to place its address
 * into %rdx.  The original return address is passed back in SYSCALL_REG.
 */
ENTRY(XXX_brand_sysenter_callback)
        CALLBACK_PROLOGUE(XXX_emulation_table, SPD_HANDLER, SYSCALL_REG,
            SCR_REG, SCR_REGB);
        CALC_TABLE_ADDR(SCR_REG, SPD_HANDLER);
        mov     %rdx, SYSCALL_REG; /* save orig return addr in syscall_reg */
        mov     SCR_REG, %rdx;  /* place new return addr in %rdx */
        mov     %gs:CPU_RTMP_R15, SCR_REG; /* restore scratch register */
        mov     V_SSP(SP_REG), SP_REG   /* restore user stack pointer */
        jmp     sys_sysenter_swapgs_sysexit
9:
        ret
SET_SIZE(XXX_brand_sysenter_callback)

/*
 * To 'return' to our user-space handler we need to update the user's %eip
 * pointer in the saved interrupt state on the stack.  The interrupt state was
 * pushed onto our stack automatically when the interrupt occured; see the
 * comments above.  The original return address is passed back in SYSCALL_REG.
 * See "64-BIT INTERPOSITION STACK" and "64-BIT INT STACK" in brand_asm.h.
 */
ENTRY(XXX_brand_int91_callback)
        CALLBACK_PROLOGUE(XXX_emulation_table, SPD_HANDLER, SYSCALL_REG,
            SCR_REG, SCR_REGB);
        CALC_TABLE_ADDR(SCR_REG, SPD_HANDLER); /* new ret addr is in scratch */
        mov     SCR_REG, SYSCALL_REG;   /* place new ret addr in syscallreg */
        mov     %gs:CPU_RTMP_R15, SCR_REG; /* restore scratch register */
        mov     V_SSP(SP_REG), SP_REG;  /* restore intr stack pointer */
        /*CSTYLED*/
        xchg    (SP_REG), SYSCALL_REG   /* swap new and orig. return addrs */
        jmp     sys_sysint_swapgs_iret
9:
        retq
SET_SIZE(XXX_brand_int91_callback)

#endif  /* _ASM */