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qemu/target/cris/op_helper.c
Pavel Dovgalyuk afd46fcad2 icount: fix cpu_restore_state_from_tb for non-tb-exit cases 
In icount mode, instructions that access io memory spaces in the middle
of the translation block invoke TB recompilation.  After recompilation,
such instructions become last in the TB and are allowed to access io
memory spaces.

When the code includes instruction like i386 'xchg eax, 0xffffd080'
which accesses APIC, QEMU goes into an infinite loop of the recompilation.

This instruction includes two memory accesses - one read and one write.
After the first access, APIC calls cpu_report_tpr_access, which restores
the CPU state to get the current eip.  But cpu_restore_state_from_tb
resets the cpu->can_do_io flag which makes the second memory access invalid.
Therefore the second memory access causes a recompilation of the block.
Then these operations repeat again and again.

This patch moves resetting cpu->can_do_io flag from
cpu_restore_state_from_tb to cpu_loop_exit* functions.

It also adds a parameter for cpu_restore_state which controls restoring
icount.  There is no need to restore icount when we only query CPU state
without breaking the TB.  Restoring it in such cases leads to the
incorrect flow of the virtual time.

In most cases new parameter is true (icount should be recalculated).
But there are two cases in i386 and openrisc when the CPU state is only
queried without the need to break the TB.  This patch fixes both of
these cases.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Message-Id: <20180409091320.12504.35329.stgit@pasha-VirtualBox>
[rth: Make can_do_io setting unconditional; move from cpu_exec;
make cpu_loop_exit_{noexc,restore} call cpu_loop_exit.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-04-11 09:05:22 +10:00

635 lines
14 KiB
C
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/*
* CRIS helper routines
*
* Copyright (c) 2007 AXIS Communications
* Written by Edgar E. Iglesias
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "mmu.h"
#include "exec/helper-proto.h"
#include "qemu/host-utils.h"
#include "exec/exec-all.h"
#include "exec/cpu_ldst.h"
//#define CRIS_OP_HELPER_DEBUG
#ifdef CRIS_OP_HELPER_DEBUG
#define D(x) x
#define D_LOG(...) qemu_log(__VA_ARGS__)
#else
#define D(x)
#define D_LOG(...) do { } while (0)
#endif
#if !defined(CONFIG_USER_ONLY)
/* Try to fill the TLB and return an exception if error. If retaddr is
NULL, it means that the function was called in C code (i.e. not
from generated code or from helper.c) */
void tlb_fill(CPUState *cs, target_ulong addr, int size,
MMUAccessType access_type, int mmu_idx, uintptr_t retaddr)
{
CRISCPU *cpu = CRIS_CPU(cs);
CPUCRISState *env = &cpu->env;
int ret;
D_LOG("%s pc=%x tpc=%x ra=%p\n", __func__,
env->pc, env->pregs[PR_EDA], (void *)retaddr);
ret = cris_cpu_handle_mmu_fault(cs, addr, size, access_type, mmu_idx);
if (unlikely(ret)) {
if (retaddr) {
/* now we have a real cpu fault */
if (cpu_restore_state(cs, retaddr, true)) {
/* Evaluate flags after retranslation. */
helper_top_evaluate_flags(env);
}
}
cpu_loop_exit(cs);
}
}
#endif
void helper_raise_exception(CPUCRISState *env, uint32_t index)
{
CPUState *cs = CPU(cris_env_get_cpu(env));
cs->exception_index = index;
cpu_loop_exit(cs);
}
void helper_tlb_flush_pid(CPUCRISState *env, uint32_t pid)
{
#if !defined(CONFIG_USER_ONLY)
pid &= 0xff;
if (pid != (env->pregs[PR_PID] & 0xff))
cris_mmu_flush_pid(env, env->pregs[PR_PID]);
#endif
}
void helper_spc_write(CPUCRISState *env, uint32_t new_spc)
{
#if !defined(CONFIG_USER_ONLY)
CRISCPU *cpu = cris_env_get_cpu(env);
CPUState *cs = CPU(cpu);
tlb_flush_page(cs, env->pregs[PR_SPC]);
tlb_flush_page(cs, new_spc);
#endif
}
/* Used by the tlb decoder. */
#define EXTRACT_FIELD(src, start, end) \
(((src) >> start) & ((1 << (end - start + 1)) - 1))
void helper_movl_sreg_reg(CPUCRISState *env, uint32_t sreg, uint32_t reg)
{
#if !defined(CONFIG_USER_ONLY)
CRISCPU *cpu = cris_env_get_cpu(env);
#endif
uint32_t srs;
srs = env->pregs[PR_SRS];
srs &= 3;
env->sregs[srs][sreg] = env->regs[reg];
#if !defined(CONFIG_USER_ONLY)
if (srs == 1 || srs == 2) {
if (sreg == 6) {
/* Writes to tlb-hi write to mm_cause as a side
effect. */
env->sregs[SFR_RW_MM_TLB_HI] = env->regs[reg];
env->sregs[SFR_R_MM_CAUSE] = env->regs[reg];
}
else if (sreg == 5) {
uint32_t set;
uint32_t idx;
uint32_t lo, hi;
uint32_t vaddr;
int tlb_v;
idx = set = env->sregs[SFR_RW_MM_TLB_SEL];
set >>= 4;
set &= 3;
idx &= 15;
/* We've just made a write to tlb_lo. */
lo = env->sregs[SFR_RW_MM_TLB_LO];
/* Writes are done via r_mm_cause. */
hi = env->sregs[SFR_R_MM_CAUSE];
vaddr = EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].hi,
13, 31);
vaddr <<= TARGET_PAGE_BITS;
tlb_v = EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].lo,
3, 3);
env->tlbsets[srs - 1][set][idx].lo = lo;
env->tlbsets[srs - 1][set][idx].hi = hi;
D_LOG("tlb flush vaddr=%x v=%d pc=%x\n",
vaddr, tlb_v, env->pc);
if (tlb_v) {
tlb_flush_page(CPU(cpu), vaddr);
}
}
}
#endif
}
void helper_movl_reg_sreg(CPUCRISState *env, uint32_t reg, uint32_t sreg)
{
uint32_t srs;
env->pregs[PR_SRS] &= 3;
srs = env->pregs[PR_SRS];
#if !defined(CONFIG_USER_ONLY)
if (srs == 1 || srs == 2)
{
uint32_t set;
uint32_t idx;
uint32_t lo, hi;
idx = set = env->sregs[SFR_RW_MM_TLB_SEL];
set >>= 4;
set &= 3;
idx &= 15;
/* Update the mirror regs. */
hi = env->tlbsets[srs - 1][set][idx].hi;
lo = env->tlbsets[srs - 1][set][idx].lo;
env->sregs[SFR_RW_MM_TLB_HI] = hi;
env->sregs[SFR_RW_MM_TLB_LO] = lo;
}
#endif
env->regs[reg] = env->sregs[srs][sreg];
}
static void cris_ccs_rshift(CPUCRISState *env)
{
uint32_t ccs;
/* Apply the ccs shift. */
ccs = env->pregs[PR_CCS];
ccs = (ccs & 0xc0000000) | ((ccs & 0x0fffffff) >> 10);
if (ccs & U_FLAG)
{
/* Enter user mode. */
env->ksp = env->regs[R_SP];
env->regs[R_SP] = env->pregs[PR_USP];
}
env->pregs[PR_CCS] = ccs;
}
void helper_rfe(CPUCRISState *env)
{
int rflag = env->pregs[PR_CCS] & R_FLAG;
D_LOG("rfe: erp=%x pid=%x ccs=%x btarget=%x\n",
env->pregs[PR_ERP], env->pregs[PR_PID],
env->pregs[PR_CCS],
env->btarget);
cris_ccs_rshift(env);
/* RFE sets the P_FLAG only if the R_FLAG is not set. */
if (!rflag)
env->pregs[PR_CCS] |= P_FLAG;
}
void helper_rfn(CPUCRISState *env)
{
int rflag = env->pregs[PR_CCS] & R_FLAG;
D_LOG("rfn: erp=%x pid=%x ccs=%x btarget=%x\n",
env->pregs[PR_ERP], env->pregs[PR_PID],
env->pregs[PR_CCS],
env->btarget);
cris_ccs_rshift(env);
/* Set the P_FLAG only if the R_FLAG is not set. */
if (!rflag)
env->pregs[PR_CCS] |= P_FLAG;
/* Always set the M flag. */
env->pregs[PR_CCS] |= M_FLAG_V32;
}
uint32_t helper_btst(CPUCRISState *env, uint32_t t0, uint32_t t1, uint32_t ccs)
{
/* FIXME: clean this up. */
/* des ref:
The N flag is set according to the selected bit in the dest reg.
The Z flag is set if the selected bit and all bits to the right are
zero.
The X flag is cleared.
Other flags are left untouched.
The destination reg is not affected.*/
unsigned int fz, sbit, bset, mask, masked_t0;
sbit = t1 & 31;
bset = !!(t0 & (1 << sbit));
mask = sbit == 31 ? -1 : (1 << (sbit + 1)) - 1;
masked_t0 = t0 & mask;
fz = !(masked_t0 | bset);
/* Clear the X, N and Z flags. */
ccs = ccs & ~(X_FLAG | N_FLAG | Z_FLAG);
if (env->pregs[PR_VR] < 32)
ccs &= ~(V_FLAG | C_FLAG);
/* Set the N and Z flags accordingly. */
ccs |= (bset << 3) | (fz << 2);
return ccs;
}
static inline uint32_t evaluate_flags_writeback(CPUCRISState *env,
uint32_t flags, uint32_t ccs)
{
unsigned int x, z, mask;
/* Extended arithmetics, leave the z flag alone. */
x = env->cc_x;
mask = env->cc_mask | X_FLAG;
if (x) {
z = flags & Z_FLAG;
mask = mask & ~z;
}
flags &= mask;
/* all insn clear the x-flag except setf or clrf. */
ccs &= ~mask;
ccs |= flags;
return ccs;
}
uint32_t helper_evaluate_flags_muls(CPUCRISState *env,
uint32_t ccs, uint32_t res, uint32_t mof)
{
uint32_t flags = 0;
int64_t tmp;
int dneg;
dneg = ((int32_t)res) < 0;
tmp = mof;
tmp <<= 32;
tmp |= res;
if (tmp == 0)
flags |= Z_FLAG;
else if (tmp < 0)
flags |= N_FLAG;
if ((dneg && mof != -1)
|| (!dneg && mof != 0))
flags |= V_FLAG;
return evaluate_flags_writeback(env, flags, ccs);
}
uint32_t helper_evaluate_flags_mulu(CPUCRISState *env,
uint32_t ccs, uint32_t res, uint32_t mof)
{
uint32_t flags = 0;
uint64_t tmp;
tmp = mof;
tmp <<= 32;
tmp |= res;
if (tmp == 0)
flags |= Z_FLAG;
else if (tmp >> 63)
flags |= N_FLAG;
if (mof)
flags |= V_FLAG;
return evaluate_flags_writeback(env, flags, ccs);
}
uint32_t helper_evaluate_flags_mcp(CPUCRISState *env, uint32_t ccs,
uint32_t src, uint32_t dst, uint32_t res)
{
uint32_t flags = 0;
src = src & 0x80000000;
dst = dst & 0x80000000;
if ((res & 0x80000000L) != 0L)
{
flags |= N_FLAG;
if (!src && !dst)
flags |= V_FLAG;
else if (src & dst)
flags |= R_FLAG;
}
else
{
if (res == 0L)
flags |= Z_FLAG;
if (src & dst)
flags |= V_FLAG;
if (dst | src)
flags |= R_FLAG;
}
return evaluate_flags_writeback(env, flags, ccs);
}
uint32_t helper_evaluate_flags_alu_4(CPUCRISState *env, uint32_t ccs,
uint32_t src, uint32_t dst, uint32_t res)
{
uint32_t flags = 0;
src = src & 0x80000000;
dst = dst & 0x80000000;
if ((res & 0x80000000L) != 0L)
{
flags |= N_FLAG;
if (!src && !dst)
flags |= V_FLAG;
else if (src & dst)
flags |= C_FLAG;
}
else
{
if (res == 0L)
flags |= Z_FLAG;
if (src & dst)
flags |= V_FLAG;
if (dst | src)
flags |= C_FLAG;
}
return evaluate_flags_writeback(env, flags, ccs);
}
uint32_t helper_evaluate_flags_sub_4(CPUCRISState *env, uint32_t ccs,
uint32_t src, uint32_t dst, uint32_t res)
{
uint32_t flags = 0;
src = (~src) & 0x80000000;
dst = dst & 0x80000000;
if ((res & 0x80000000L) != 0L)
{
flags |= N_FLAG;
if (!src && !dst)
flags |= V_FLAG;
else if (src & dst)
flags |= C_FLAG;
}
else
{
if (res == 0L)
flags |= Z_FLAG;
if (src & dst)
flags |= V_FLAG;
if (dst | src)
flags |= C_FLAG;
}
flags ^= C_FLAG;
return evaluate_flags_writeback(env, flags, ccs);
}
uint32_t helper_evaluate_flags_move_4(CPUCRISState *env,
uint32_t ccs, uint32_t res)
{
uint32_t flags = 0;
if ((int32_t)res < 0)
flags |= N_FLAG;
else if (res == 0L)
flags |= Z_FLAG;
return evaluate_flags_writeback(env, flags, ccs);
}
uint32_t helper_evaluate_flags_move_2(CPUCRISState *env,
uint32_t ccs, uint32_t res)
{
uint32_t flags = 0;
if ((int16_t)res < 0L)
flags |= N_FLAG;
else if (res == 0)
flags |= Z_FLAG;
return evaluate_flags_writeback(env, flags, ccs);
}
/* TODO: This is expensive. We could split things up and only evaluate part of
CCR on a need to know basis. For now, we simply re-evaluate everything. */
void helper_evaluate_flags(CPUCRISState *env)
{
uint32_t src, dst, res;
uint32_t flags = 0;
src = env->cc_src;
dst = env->cc_dest;
res = env->cc_result;
if (env->cc_op == CC_OP_SUB || env->cc_op == CC_OP_CMP)
src = ~src;
/* Now, evaluate the flags. This stuff is based on
Per Zander's CRISv10 simulator. */
switch (env->cc_size)
{
case 1:
if ((res & 0x80L) != 0L)
{
flags |= N_FLAG;
if (((src & 0x80L) == 0L)
&& ((dst & 0x80L) == 0L))
{
flags |= V_FLAG;
}
else if (((src & 0x80L) != 0L)
&& ((dst & 0x80L) != 0L))
{
flags |= C_FLAG;
}
}
else
{
if ((res & 0xFFL) == 0L)
{
flags |= Z_FLAG;
}
if (((src & 0x80L) != 0L)
&& ((dst & 0x80L) != 0L))
{
flags |= V_FLAG;
}
if ((dst & 0x80L) != 0L
|| (src & 0x80L) != 0L)
{
flags |= C_FLAG;
}
}
break;
case 2:
if ((res & 0x8000L) != 0L)
{
flags |= N_FLAG;
if (((src & 0x8000L) == 0L)
&& ((dst & 0x8000L) == 0L))
{
flags |= V_FLAG;
}
else if (((src & 0x8000L) != 0L)
&& ((dst & 0x8000L) != 0L))
{
flags |= C_FLAG;
}
}
else
{
if ((res & 0xFFFFL) == 0L)
{
flags |= Z_FLAG;
}
if (((src & 0x8000L) != 0L)
&& ((dst & 0x8000L) != 0L))
{
flags |= V_FLAG;
}
if ((dst & 0x8000L) != 0L
|| (src & 0x8000L) != 0L)
{
flags |= C_FLAG;
}
}
break;
case 4:
if ((res & 0x80000000L) != 0L)
{
flags |= N_FLAG;
if (((src & 0x80000000L) == 0L)
&& ((dst & 0x80000000L) == 0L))
{
flags |= V_FLAG;
}
else if (((src & 0x80000000L) != 0L) &&
((dst & 0x80000000L) != 0L))
{
flags |= C_FLAG;
}
}
else
{
if (res == 0L)
flags |= Z_FLAG;
if (((src & 0x80000000L) != 0L)
&& ((dst & 0x80000000L) != 0L))
flags |= V_FLAG;
if ((dst & 0x80000000L) != 0L
|| (src & 0x80000000L) != 0L)
flags |= C_FLAG;
}
break;
default:
break;
}
if (env->cc_op == CC_OP_SUB || env->cc_op == CC_OP_CMP)
flags ^= C_FLAG;
env->pregs[PR_CCS] = evaluate_flags_writeback(env, flags,
env->pregs[PR_CCS]);
}
void helper_top_evaluate_flags(CPUCRISState *env)
{
switch (env->cc_op)
{
case CC_OP_MCP:
env->pregs[PR_CCS] = helper_evaluate_flags_mcp(env,
env->pregs[PR_CCS], env->cc_src,
env->cc_dest, env->cc_result);
break;
case CC_OP_MULS:
env->pregs[PR_CCS] = helper_evaluate_flags_muls(env,
env->pregs[PR_CCS], env->cc_result,
env->pregs[PR_MOF]);
break;
case CC_OP_MULU:
env->pregs[PR_CCS] = helper_evaluate_flags_mulu(env,
env->pregs[PR_CCS], env->cc_result,
env->pregs[PR_MOF]);
break;
case CC_OP_MOVE:
case CC_OP_AND:
case CC_OP_OR:
case CC_OP_XOR:
case CC_OP_ASR:
case CC_OP_LSR:
case CC_OP_LSL:
switch (env->cc_size)
{
case 4:
env->pregs[PR_CCS] =
helper_evaluate_flags_move_4(env,
env->pregs[PR_CCS],
env->cc_result);
break;
case 2:
env->pregs[PR_CCS] =
helper_evaluate_flags_move_2(env,
env->pregs[PR_CCS],
env->cc_result);
break;
default:
helper_evaluate_flags(env);
break;
}
break;
case CC_OP_FLAGS:
/* live. */
break;
case CC_OP_SUB:
case CC_OP_CMP:
if (env->cc_size == 4)
env->pregs[PR_CCS] =
helper_evaluate_flags_sub_4(env,
env->pregs[PR_CCS],
env->cc_src, env->cc_dest,
env->cc_result);
else
helper_evaluate_flags(env);
break;
default:
{
switch (env->cc_size)
{
case 4:
env->pregs[PR_CCS] =
helper_evaluate_flags_alu_4(env,
env->pregs[PR_CCS],
env->cc_src, env->cc_dest,
env->cc_result);
break;
default:
helper_evaluate_flags(env);
break;
}
}
break;
}
}
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