md-os.cpp

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/* src/vm/jit/sparc64/linux/md-os.cpp - machine dependent SPARC Linux functions

   Copyright (C) 1996-2013
   CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO

   This file is part of CACAO.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.

*/


#include "config.h"

#include <cassert>
#include <stdint.h>
#include <signal.h>

#include "vm/types.hpp"

#include "vm/jit/sparc64/codegen.hpp"
#include "vm/jit/sparc64/md-abi.hpp"

#include "vm/signallocal.hpp"

#include "vm/jit/asmpart.hpp"
#include "vm/jit/stacktrace.hpp"
#include "vm/jit/trap.hpp"


typedef struct sigcontext sigcontext;

ptrint md_get_reg_from_context(sigcontext *ctx, u4 rindex)
{
    ptrint val; 
    s8     *window;
    
    
    /* return 0 for REG_ZERO */
    
    if (rindex == 0)
        return 0;
        
    
    if (rindex <= 15) {
        
        /* register is in global or out range, available in context */
        
        val = ctx->sigc_regs.u_regs[rindex];
    }
    else {
        assert(rindex <= 31);
        
        /* register is local or in, need to fetch from regsave area on stack */
        
        window = ctx->sigc_regs.u_regs[REG_SP] + BIAS;
        val = window[rindex - 16];
    }
    
    return val;
}
    
    

/* md_signal_handler_sigsegv ***************************************************

   NullPointerException signal handler for hardware null pointer
   check.

*******************************************************************************/

void md_signal_handler_sigsegv(int sig, siginfo_t *info , void *_p)
{
    /*
    ucontext_t  *_uc;
    mcontext_t  *_mc;
    */
    sigcontext *ctx;
    u1          *pv;
    u1          *sp;
    u1          *ra;
    u1          *xpc;
    u4          mcode;
    int         d;
    int         s1;
    int16_t     disp;
    intptr_t    val;
    intptr_t    addr;
    int         type;
    void       *p;

    ctx = (sigcontext *) info;


    pv  = (u1 *) md_get_reg_from_context(ctx, REG_PV_CALLEE);
    sp  = (u1 *) md_get_reg_from_context(ctx, REG_SP);
    ra  = (u1 *) md_get_reg_from_context(ctx, REG_RA_CALLEE);  /* this is correct for leafs */
    xpc = (u1 *) ctx->sigc_regs.tpc;

    /* get exception-throwing instruction */    

    mcode = *((u4 *) xpc);

    d    = M_OP3_GET_RD(mcode);
    s1   = M_OP3_GET_RS(mcode);
    disp = M_OP3_GET_IMM(mcode);

    /* flush register windows? */
    
    val  = md_get_reg_from_context(ctx, d);

    /* check for special-load */

    if (s1 == REG_ZERO) {
        /* we use the exception type as load displacement */

        type = disp;
    }
    else {
        /* This is a normal NPE: addr must be NULL and the NPE-type
           define is 0. */

        addr = md_get_reg_from_context(ctx, s1);
        type = (int) addr;
    }

    /* Handle the trap. */

    p = trap_handle(type, val, pv, sp, ra, xpc, _p);

    /* set registers */

    ctx->sigc_regs.u_regs[REG_ITMP2_XPTR] = (uintptr_t) p;
    ctx->sigc_regs.u_regs[REG_ITMP3_XPC]  = (uintptr_t) xpc;
    ctx->sigc_regs.tpc                    = (uintptr_t) asm_handle_exception;
    ctx->sigc_regs.tnpc                   = (uintptr_t) asm_handle_exception + 4;
}


/* md_icacheflush **************************************************************

   Calls the system's function to flush the instruction cache.

*******************************************************************************/

void md_icacheflush(u1 *addr, s4 nbytes)
{
    u1* end;
    
    end = addr + nbytes;
    
    /* zero the least significant 3 bits to align on a 64-bit boundary */
    addr = (u1 *) (((ptrint) addr) & -8l);
    
    while (addr < end) {
        __asm__ (
            "flush %0"
            :
            : "r"(addr)
            );
        addr += 8;
    }
}

    
/*
 * These are local overrides for various environment variables in Emacs.
 * Please do not remove this and leave it at the end of the file, where
 * Emacs will automagically detect them.
 * ---------------------------------------------------------------------
 * Local variables:
 * mode: c++
 * indent-tabs-mode: t
 * c-basic-offset: 4
 * tab-width: 4
 * End:
 * vim:noexpandtab:sw=4:ts=4:
 */