/*
 * 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) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include "lint.h"
#include "thr_uberdata.h"
#include <procfs.h>
#include <ucontext.h>
#include <setjmp.h>
#include "sigjmp_struct.h"

extern int getlwpstatus(thread_t, lwpstatus_t *);
extern int putlwpregs(thread_t, prgregset_t);

void *
setup_top_frame(void *stk, size_t stksize, ulwp_t *ulwp __unused)
{
        uint64_t *stack;
        struct {
                uint64_t        rpc;
                uint64_t        fp;
                uint64_t        pc;
        } frame;

        /*
         * Top-of-stack must be rounded down to STACK_ALIGN and
         * there must be a minimum frame.
         */
        stack = (uint64_t *)(((uintptr_t)stk + stksize) & ~(STACK_ALIGN-1));

        /*
         * This will return NULL if the kernel cannot allocate
         * a page for the top page of the stack.  This will cause
         * thr_create(), pthread_create() or pthread_attr_setstack()
         * to fail, passing the problem up to the application.
         */
        stack -= 3;
        frame.pc = 0;
        frame.fp = 0;
        frame.rpc = (uint64_t)_lwp_start;
        if (uucopy(&frame, stack, sizeof (frame)) == 0)
                return (stack);
        return (NULL);
}

int
setup_context(ucontext_t *ucp, void *(*func)(ulwp_t *),
    ulwp_t *ulwp, caddr_t stk, size_t stksize)
{
        uint64_t *stack;

        /* clear the context */
        (void) memset(ucp, 0, sizeof (*ucp));

        /* setup to store the current thread pointer in %fs */
        ucp->uc_mcontext.gregs[REG_FSBASE] = (greg_t)ulwp;
        ucp->uc_mcontext.gregs[REG_FS] = 0; /* null selector indicates fsbase */

        /* all contexts should have a valid data segment descriptor for %ss */
        ucp->uc_mcontext.gregs[REG_SS] = UDS_SEL;

        /*
         * Setup the top stack frame.
         * If this fails, pass the problem up to the application.
         */
        if ((stack = setup_top_frame(stk, stksize, ulwp)) == NULL)
                return (ENOMEM);

        /* fill in registers of interest */
        ucp->uc_flags |= UC_CPU;
        ucp->uc_mcontext.gregs[REG_RDI] = (greg_t)ulwp;
        ucp->uc_mcontext.gregs[REG_RIP] = (greg_t)func;
        ucp->uc_mcontext.gregs[REG_RSP] = (greg_t)stack;
        ucp->uc_mcontext.gregs[REG_RBP] = (greg_t)(stack + 1);

        return (0);
}

/*
 * Machine-dependent startup code for a newly-created thread.
 */
void *
_thrp_setup(ulwp_t *self)
{
        self->ul_ustack.ss_sp = (void *)(self->ul_stktop - self->ul_stksiz);
        self->ul_ustack.ss_size = self->ul_stksiz;
        self->ul_ustack.ss_flags = 0;
        (void) setustack(&self->ul_ustack);

        update_sched(self);
        tls_setup();

        /* signals have been deferred until now */
        sigon(self);

        if (self->ul_cancel_pending == 2 && !self->ul_cancel_disabled)
                return (NULL);  /* cancelled by pthread_create() */
        return (self->ul_startpc(self->ul_startarg));
}

void
_fpinherit(ulwp_t *ulwp)
{
        ulwp->ul_fpuenv.ftag = 0xffffffff;
}

void
getgregs(ulwp_t *ulwp, gregset_t rs)
{
        lwpstatus_t status;

        if (getlwpstatus(ulwp->ul_lwpid, &status) == 0) {
                rs[REG_RBX] = status.pr_reg[REG_RBX];
                rs[REG_R12] = status.pr_reg[REG_R12];
                rs[REG_R13] = status.pr_reg[REG_R13];
                rs[REG_R14] = status.pr_reg[REG_R14];
                rs[REG_R15] = status.pr_reg[REG_R15];
                rs[REG_RBP] = status.pr_reg[REG_RBP];
                rs[REG_RSP] = status.pr_reg[REG_RSP];
                rs[REG_RIP] = status.pr_reg[REG_RIP];
        } else {
                rs[REG_RBX] = 0;
                rs[REG_R12] = 0;
                rs[REG_R13] = 0;
                rs[REG_R14] = 0;
                rs[REG_R15] = 0;
                rs[REG_RBP] = 0;
                rs[REG_RSP] = 0;
                rs[REG_RIP] = 0;
        }
}

void
setgregs(ulwp_t *ulwp, gregset_t rs)
{
        lwpstatus_t status;

        if (getlwpstatus(ulwp->ul_lwpid, &status) == 0) {
                status.pr_reg[REG_RBX] = rs[REG_RBX];
                status.pr_reg[REG_R12] = rs[REG_R12];
                status.pr_reg[REG_R13] = rs[REG_R13];
                status.pr_reg[REG_R14] = rs[REG_R14];
                status.pr_reg[REG_R15] = rs[REG_R15];
                status.pr_reg[REG_RBP] = rs[REG_RBP];
                status.pr_reg[REG_RSP] = rs[REG_RSP];
                status.pr_reg[REG_RIP] = rs[REG_RIP];
                (void) putlwpregs(ulwp->ul_lwpid, status.pr_reg);
        }
}

int
__csigsetjmp(sigjmp_buf env, int savemask, gregset_t rs)
{
        ucontext_t *ucp = SIGJMP2UCONTEXT(env);
        ulwp_t *self = curthread;

        ucp->uc_link = self->ul_siglink;
        if (self->ul_ustack.ss_flags & SS_ONSTACK)
                ucp->uc_stack = self->ul_ustack;
        else {
                ucp->uc_stack.ss_sp =
                    (void *)(self->ul_stktop - self->ul_stksiz);
                ucp->uc_stack.ss_size = self->ul_stksiz;
                ucp->uc_stack.ss_flags = 0;
        }
        ucp->uc_flags = UC_STACK | UC_CPU;
        if (savemask) {
                ucp->uc_flags |= UC_SIGMASK;
                enter_critical(self);
                ucp->uc_sigmask = self->ul_sigmask;
                exit_critical(self);
        }
        (void) memcpy(ucp->uc_mcontext.gregs, rs, _NGREG * sizeof (greg_t));

        return (0);
}

void
smt_pause(void)
{
        SMT_PAUSE();
}