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very slight optimization in io permissions check

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This commit is contained in:
Stanislav Shwartsman 2008-08-27 21:26:23 +00:00
parent 53426fc136
commit b1da3d7d46
1 changed files with 31 additions and 34 deletions
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65
bochs/cpu/io_pro.cc
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@ -1,5 +1,5 @@
/////////////////////////////////////////////////////////////////////////
// $Id: io_pro.cc,v 1.35 2008-06-14 16:55:45 sshwarts Exp $
// $Id: io_pro.cc,v 1.36 2008-08-27 21:26:23 sshwarts Exp $
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2001 MandrakeSoft S.A.
@ -34,84 +34,84 @@
#include "iodev/iodev.h"
Bit16u BX_CPP_AttrRegparmN(1)
BX_CPU_C::inp16(Bit16u addr)
BX_CPU_C::inp16(Bit16u port)
{
if (! BX_CPU_THIS_PTR allow_io(addr, 2)) {
if (! BX_CPU_THIS_PTR allow_io(port, 2)) {
BX_DEBUG(("inp16(): I/O access not allowed !"));
exception(BX_GP_EXCEPTION, 0, 0);
}
Bit16u ret16 = BX_INP(addr, 2);
Bit16u ret16 = BX_INP(port, 2);
return ret16;
}
void BX_CPP_AttrRegparmN(2)
BX_CPU_C::outp16(Bit16u addr, Bit16u value)
BX_CPU_C::outp16(Bit16u port, Bit16u value)
{
if (! BX_CPU_THIS_PTR allow_io(addr, 2)) {
if (! BX_CPU_THIS_PTR allow_io(port, 2)) {
BX_DEBUG(("outp16(): I/O access not allowed !"));
exception(BX_GP_EXCEPTION, 0, 0);
}
BX_OUTP(addr, value, 2);
BX_OUTP(port, value, 2);
}
Bit32u BX_CPP_AttrRegparmN(1)
BX_CPU_C::inp32(Bit16u addr)
BX_CPU_C::inp32(Bit16u port)
{
if (! BX_CPU_THIS_PTR allow_io(addr, 4)) {
if (! BX_CPU_THIS_PTR allow_io(port, 4)) {
BX_DEBUG(("inp32(): I/O access not allowed !"));
exception(BX_GP_EXCEPTION, 0, 0);
}
Bit32u ret32 = BX_INP(addr, 4);
Bit32u ret32 = BX_INP(port, 4);
return ret32;
}
void BX_CPP_AttrRegparmN(2)
BX_CPU_C::outp32(Bit16u addr, Bit32u value)
BX_CPU_C::outp32(Bit16u port, Bit32u value)
{
if (! BX_CPU_THIS_PTR allow_io(addr, 4)) {
if (! BX_CPU_THIS_PTR allow_io(port, 4)) {
BX_DEBUG(("outp32(): I/O access not allowed !"));
exception(BX_GP_EXCEPTION, 0, 0);
}
BX_OUTP(addr, value, 4);
BX_OUTP(port, value, 4);
}
Bit8u BX_CPP_AttrRegparmN(1)
BX_CPU_C::inp8(Bit16u addr)
BX_CPU_C::inp8(Bit16u port)
{
if (! BX_CPU_THIS_PTR allow_io(addr, 1)) {
if (! BX_CPU_THIS_PTR allow_io(port, 1)) {
BX_DEBUG(("inp8(): I/O access not allowed !"));
exception(BX_GP_EXCEPTION, 0, 0);
}
Bit8u ret8 = BX_INP(addr, 1);
Bit8u ret8 = BX_INP(port, 1);
return ret8;
}
void BX_CPP_AttrRegparmN(2)
BX_CPU_C::outp8(Bit16u addr, Bit8u value)
BX_CPU_C::outp8(Bit16u port, Bit8u value)
{
if (! BX_CPU_THIS_PTR allow_io(addr, 1)) {
if (! BX_CPU_THIS_PTR allow_io(port, 1)) {
BX_DEBUG(("outp8(): I/O access not allowed !"));
exception(BX_GP_EXCEPTION, 0, 0);
}
BX_OUTP(addr, value, 1);
BX_OUTP(port, value, 1);
}
bx_bool BX_CPU_C::allow_io(Bit16u addr, unsigned len)
bx_bool BX_CPU_C::allow_io(Bit16u port, unsigned len)
{
Bit16u io_base, permission16;
/* If CPL <= IOPL, then all IO addresses are accessible.
/* If CPL <= IOPL, then all IO portesses are accessible.
* Otherwise, must check the IO permission map on >286.
* On the 286, there is no IO permissions map */
if (BX_CPU_THIS_PTR cr0.get_PE() && (BX_CPU_THIS_PTR get_VM() || (CPL>BX_CPU_THIS_PTR get_IOPL())))
{
Bit16u io_base, permission16;
if (BX_CPU_THIS_PTR tr.cache.valid==0 ||
(BX_CPU_THIS_PTR tr.cache.type != BX_SYS_SEGMENT_AVAIL_386_TSS &&
BX_CPU_THIS_PTR tr.cache.type != BX_SYS_SEGMENT_BUSY_386_TSS))
@ -128,22 +128,19 @@ bx_bool BX_CPU_C::allow_io(Bit16u addr, unsigned len)
access_read_linear(BX_CPU_THIS_PTR tr.cache.u.system.base + 102,
2, 0, BX_READ, &io_base);
if ((io_base + addr/8) >= BX_CPU_THIS_PTR tr.cache.u.system.limit_scaled) {
BX_ERROR(("allow_io(): IO addr %x (len %d) outside TSS IO permission map (base=%x, limit=%x) #GP(0)",
addr, len, io_base, BX_CPU_THIS_PTR tr.cache.u.system.limit_scaled));
if ((io_base + port/8) >= BX_CPU_THIS_PTR tr.cache.u.system.limit_scaled) {
BX_ERROR(("allow_io(): IO port %x (len %d) outside TSS IO permission map (base=%x, limit=%x) #GP(0)",
port, len, io_base, BX_CPU_THIS_PTR tr.cache.u.system.limit_scaled));
return(0);
}
access_read_linear(BX_CPU_THIS_PTR tr.cache.u.system.base + io_base + addr/8,
access_read_linear(BX_CPU_THIS_PTR tr.cache.u.system.base + io_base + port/8,
2, 0, BX_READ, &permission16);
unsigned bit_index = addr & 0x07;
permission16 >>= bit_index;
for (unsigned n=0; n<len; n++) {
if (permission16 & 0x01)
return(0);
permission16 >>= 1;
}
unsigned bit_index = port & 0x7;
unsigned mask = (1 << len) - 1;
if ((permission16 >> bit_index) & mask)
return(0);
}
return(1);