mirror of
https://github.com/yuzu-emu/unicorn.git
synced 2024-12-25 14:55:31 +00:00
8840d8370d
Currently we use DISAS_WFE for both WFE and YIELD instructions. This is functionally correct because at the moment both of them are implemented as "yield this CPU back to the top level loop so another CPU has a chance to run". However it's rather confusing that YIELD ends up calling HELPER(wfe), and if we ever want to implement real behaviour for WFE and SEV it's likely to trip us up. Split out the yield codepath to use DISAS_YIELD and a new HELPER(yield) function, and have HELPER(wfe) call HELPER(yield). Backports commit 049e24a191c212d9468db84169197887f2c91586 from qemu
969 lines
27 KiB
C
969 lines
27 KiB
C
/*
|
|
* ARM helper routines
|
|
*
|
|
* Copyright (c) 2005-2007 CodeSourcery, LLC
|
|
*
|
|
* 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 "cpu.h"
|
|
#include "exec/helper-proto.h"
|
|
#include "internals.h"
|
|
#include "exec/cpu_ldst.h"
|
|
|
|
#define SIGNBIT (uint32_t)0x80000000
|
|
#define SIGNBIT64 ((uint64_t)1 << 63)
|
|
|
|
static void raise_exception(CPUARMState *env, uint32_t excp,
|
|
uint32_t syndrome, uint32_t target_el)
|
|
{
|
|
CPUState *cs = CPU(arm_env_get_cpu(env));
|
|
|
|
assert(!excp_is_internal(excp));
|
|
cs->exception_index = excp;
|
|
env->exception.syndrome = syndrome;
|
|
env->exception.target_el = target_el;
|
|
cpu_loop_exit(cs);
|
|
}
|
|
|
|
static int exception_target_el(CPUARMState *env)
|
|
{
|
|
int target_el = MAX(1, arm_current_el(env));
|
|
|
|
/* No such thing as secure EL1 if EL3 is aarch32, so update the target EL
|
|
* to EL3 in this case.
|
|
*/
|
|
if (arm_is_secure(env) && !arm_el_is_aa64(env, 3) && target_el == 1) {
|
|
target_el = 3;
|
|
}
|
|
|
|
return target_el;
|
|
}
|
|
|
|
uint32_t HELPER(neon_tbl)(CPUARMState *env, uint32_t ireg, uint32_t def,
|
|
uint32_t rn, uint32_t maxindex)
|
|
{
|
|
uint32_t val;
|
|
uint32_t tmp;
|
|
int index;
|
|
int shift;
|
|
uint64_t *table;
|
|
table = (uint64_t *)&env->vfp.regs[rn];
|
|
val = 0;
|
|
for (shift = 0; shift < 32; shift += 8) {
|
|
index = (ireg >> shift) & 0xff;
|
|
if (index < maxindex) {
|
|
tmp = (table[index >> 3] >> ((index & 7) << 3)) & 0xff;
|
|
val |= tmp << shift;
|
|
} else {
|
|
val |= def & (0xff << shift);
|
|
}
|
|
}
|
|
return val;
|
|
}
|
|
|
|
#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 is_write, int mmu_idx,
|
|
uintptr_t retaddr)
|
|
{
|
|
bool ret;
|
|
uint32_t fsr = 0;
|
|
|
|
ret = arm_tlb_fill(cs, addr, is_write, mmu_idx, &fsr);
|
|
if (unlikely(ret)) {
|
|
ARMCPU *cpu = ARM_CPU(cs->uc, cs);
|
|
CPUARMState *env = &cpu->env;
|
|
uint32_t syn, exc;
|
|
bool same_el = (arm_current_el(env) != 0);
|
|
|
|
if (retaddr) {
|
|
/* now we have a real cpu fault */
|
|
cpu_restore_state(cs, retaddr);
|
|
}
|
|
|
|
/* AArch64 syndrome does not have an LPAE bit */
|
|
syn = fsr & ~(1 << 9);
|
|
|
|
/* For insn and data aborts we assume there is no instruction syndrome
|
|
* information; this is always true for exceptions reported to EL1.
|
|
*/
|
|
if (is_write == 2) {
|
|
syn = syn_insn_abort(same_el, 0, 0, syn);
|
|
exc = EXCP_PREFETCH_ABORT;
|
|
} else {
|
|
syn = syn_data_abort(same_el, 0, 0, 0, is_write == 1, syn);
|
|
if (is_write == 1 && arm_feature(env, ARM_FEATURE_V6)) {
|
|
fsr |= (1 << 11);
|
|
}
|
|
exc = EXCP_DATA_ABORT;
|
|
}
|
|
|
|
env->exception.vaddress = addr;
|
|
env->exception.fsr = fsr;
|
|
raise_exception(env, exc, syn, exception_target_el(env));
|
|
}
|
|
}
|
|
#endif
|
|
|
|
uint32_t HELPER(add_setq)(CPUARMState *env, uint32_t a, uint32_t b)
|
|
{
|
|
uint32_t res = a + b;
|
|
if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT))
|
|
env->QF = 1;
|
|
return res;
|
|
}
|
|
|
|
uint32_t HELPER(add_saturate)(CPUARMState *env, uint32_t a, uint32_t b)
|
|
{
|
|
uint32_t res = a + b;
|
|
if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) {
|
|
env->QF = 1;
|
|
res = ~(((int32_t)a >> 31) ^ SIGNBIT);
|
|
}
|
|
return res;
|
|
}
|
|
|
|
uint32_t HELPER(sub_saturate)(CPUARMState *env, uint32_t a, uint32_t b)
|
|
{
|
|
uint32_t res = a - b;
|
|
if (((res ^ a) & SIGNBIT) && ((a ^ b) & SIGNBIT)) {
|
|
env->QF = 1;
|
|
res = ~(((int32_t)a >> 31) ^ SIGNBIT);
|
|
}
|
|
return res;
|
|
}
|
|
|
|
uint32_t HELPER(double_saturate)(CPUARMState *env, int32_t val)
|
|
{
|
|
uint32_t res;
|
|
if (val >= 0x40000000) {
|
|
res = ~SIGNBIT;
|
|
env->QF = 1;
|
|
} else if (val <= (int32_t)0xc0000000) {
|
|
res = SIGNBIT;
|
|
env->QF = 1;
|
|
} else {
|
|
res = val << 1;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
uint32_t HELPER(add_usaturate)(CPUARMState *env, uint32_t a, uint32_t b)
|
|
{
|
|
uint32_t res = a + b;
|
|
if (res < a) {
|
|
env->QF = 1;
|
|
res = ~0;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
uint32_t HELPER(sub_usaturate)(CPUARMState *env, uint32_t a, uint32_t b)
|
|
{
|
|
uint32_t res = a - b;
|
|
if (res > a) {
|
|
env->QF = 1;
|
|
res = 0;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
/* Signed saturation. */
|
|
static inline uint32_t do_ssat(CPUARMState *env, int32_t val, int shift)
|
|
{
|
|
int32_t top;
|
|
uint32_t mask;
|
|
|
|
top = val >> shift;
|
|
mask = (1u << shift) - 1;
|
|
if (top > 0) {
|
|
env->QF = 1;
|
|
return mask;
|
|
} else if (top < -1) {
|
|
env->QF = 1;
|
|
return ~mask;
|
|
}
|
|
return val;
|
|
}
|
|
|
|
/* Unsigned saturation. */
|
|
static inline uint32_t do_usat(CPUARMState *env, int32_t val, int shift)
|
|
{
|
|
uint32_t max;
|
|
|
|
max = (1u << shift) - 1;
|
|
if (val < 0) {
|
|
env->QF = 1;
|
|
return 0;
|
|
} else if (val > max) {
|
|
env->QF = 1;
|
|
return max;
|
|
}
|
|
return val;
|
|
}
|
|
|
|
/* Signed saturate. */
|
|
uint32_t HELPER(ssat)(CPUARMState *env, uint32_t x, uint32_t shift)
|
|
{
|
|
return do_ssat(env, x, shift);
|
|
}
|
|
|
|
/* Dual halfword signed saturate. */
|
|
uint32_t HELPER(ssat16)(CPUARMState *env, uint32_t x, uint32_t shift)
|
|
{
|
|
uint32_t res;
|
|
|
|
res = (uint16_t)do_ssat(env, (int16_t)x, shift);
|
|
res |= do_ssat(env, ((int32_t)x) >> 16, shift) << 16;
|
|
return res;
|
|
}
|
|
|
|
/* Unsigned saturate. */
|
|
uint32_t HELPER(usat)(CPUARMState *env, uint32_t x, uint32_t shift)
|
|
{
|
|
return do_usat(env, x, shift);
|
|
}
|
|
|
|
/* Dual halfword unsigned saturate. */
|
|
uint32_t HELPER(usat16)(CPUARMState *env, uint32_t x, uint32_t shift)
|
|
{
|
|
uint32_t res;
|
|
|
|
res = (uint16_t)do_usat(env, (int16_t)x, shift);
|
|
res |= do_usat(env, ((int32_t)x) >> 16, shift) << 16;
|
|
return res;
|
|
}
|
|
|
|
/* Function checks whether WFx (WFI/WFE) instructions are set up to be trapped.
|
|
* The function returns the target EL (1-3) if the instruction is to be trapped;
|
|
* otherwise it returns 0 indicating it is not trapped.
|
|
*/
|
|
static inline int check_wfx_trap(CPUARMState *env, bool is_wfe)
|
|
{
|
|
int cur_el = arm_current_el(env);
|
|
uint64_t mask;
|
|
|
|
/* If we are currently in EL0 then we need to check if SCTLR is set up for
|
|
* WFx instructions being trapped to EL1. These trap bits don't exist in v7.
|
|
*/
|
|
if (cur_el < 1 && arm_feature(env, ARM_FEATURE_V8)) {
|
|
int target_el;
|
|
|
|
mask = is_wfe ? SCTLR_nTWE : SCTLR_nTWI;
|
|
if (arm_is_secure_below_el3(env) && !arm_el_is_aa64(env, 3)) {
|
|
/* Secure EL0 and Secure PL1 is at EL3 */
|
|
target_el = 3;
|
|
} else {
|
|
target_el = 1;
|
|
}
|
|
|
|
if (!(env->cp15.sctlr_el[target_el] & mask)) {
|
|
return target_el;
|
|
}
|
|
}
|
|
|
|
/* We are not trapping to EL1; trap to EL2 if HCR_EL2 requires it
|
|
* No need for ARM_FEATURE check as if HCR_EL2 doesn't exist the
|
|
* bits will be zero indicating no trap.
|
|
*/
|
|
if (cur_el < 2 && !arm_is_secure(env)) {
|
|
mask = (is_wfe) ? HCR_TWE : HCR_TWI;
|
|
if (env->cp15.hcr_el2 & mask) {
|
|
return 2;
|
|
}
|
|
}
|
|
|
|
/* We are not trapping to EL1 or EL2; trap to EL3 if SCR_EL3 requires it */
|
|
if (cur_el < 3) {
|
|
mask = (is_wfe) ? SCR_TWE : SCR_TWI;
|
|
if (env->cp15.scr_el3 & mask) {
|
|
return 3;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void HELPER(wfi)(CPUARMState *env)
|
|
{
|
|
CPUState *cs = CPU(arm_env_get_cpu(env));
|
|
int target_el = check_wfx_trap(env, false);
|
|
|
|
if (cpu_has_work(cs)) {
|
|
/* Don't bother to go into our "low power state" if
|
|
* we would just wake up immediately.
|
|
*/
|
|
return;
|
|
}
|
|
|
|
if (target_el) {
|
|
env->pc -= 4;
|
|
raise_exception(env, EXCP_UDEF, syn_wfx(1, 0xe, 0), target_el);
|
|
}
|
|
|
|
cs->exception_index = EXCP_HLT;
|
|
cs->halted = 1;
|
|
cpu_loop_exit(cs);
|
|
}
|
|
|
|
void HELPER(wfe)(CPUARMState *env)
|
|
{
|
|
/* This is a hint instruction that is semantically different
|
|
* from YIELD even though we currently implement it identically.
|
|
* Don't actually halt the CPU, just yield back to top
|
|
* level loop. This is not going into a "low power state"
|
|
* (ie halting until some event occurs), so we never take
|
|
* a configurable trap to a different exception level.
|
|
*/
|
|
HELPER(yield)(env);
|
|
}
|
|
|
|
void HELPER(yield)(CPUARMState *env)
|
|
{
|
|
ARMCPU *cpu = arm_env_get_cpu(env);
|
|
CPUState *cs = CPU(cpu);
|
|
|
|
/* This is a non-trappable hint instruction that generally indicates
|
|
* that the guest is currently busy-looping. Yield control back to the
|
|
* top level loop so that a more deserving VCPU has a chance to run.
|
|
*/
|
|
cs->exception_index = EXCP_YIELD;
|
|
cpu_loop_exit(cs);
|
|
}
|
|
|
|
/* Raise an internal-to-QEMU exception. This is limited to only
|
|
* those EXCP values which are special cases for QEMU to interrupt
|
|
* execution and not to be used for exceptions which are passed to
|
|
* the guest (those must all have syndrome information and thus should
|
|
* use exception_with_syndrome).
|
|
*/
|
|
void HELPER(exception_internal)(CPUARMState *env, uint32_t excp)
|
|
{
|
|
CPUState *cs = CPU(arm_env_get_cpu(env));
|
|
|
|
assert(excp_is_internal(excp));
|
|
cs->exception_index = excp;
|
|
cpu_loop_exit(cs);
|
|
}
|
|
|
|
/* Raise an exception with the specified syndrome register value */
|
|
void HELPER(exception_with_syndrome)(CPUARMState *env, uint32_t excp,
|
|
uint32_t syndrome, uint32_t target_el)
|
|
{
|
|
raise_exception(env, excp, syndrome, target_el);
|
|
}
|
|
|
|
uint32_t HELPER(cpsr_read)(CPUARMState *env)
|
|
{
|
|
return cpsr_read(env) & ~(CPSR_EXEC | CPSR_RESERVED);
|
|
}
|
|
|
|
void HELPER(cpsr_write)(CPUARMState *env, uint32_t val, uint32_t mask)
|
|
{
|
|
cpsr_write(env, val, mask);
|
|
}
|
|
|
|
/* Access to user mode registers from privileged modes. */
|
|
uint32_t HELPER(get_user_reg)(CPUARMState *env, uint32_t regno)
|
|
{
|
|
uint32_t val;
|
|
|
|
if (regno == 13) {
|
|
val = env->banked_r13[0];
|
|
} else if (regno == 14) {
|
|
val = env->banked_r14[0];
|
|
} else if (regno >= 8
|
|
&& (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
|
|
val = env->usr_regs[regno - 8];
|
|
} else {
|
|
val = env->regs[regno];
|
|
}
|
|
return val;
|
|
}
|
|
|
|
void HELPER(set_user_reg)(CPUARMState *env, uint32_t regno, uint32_t val)
|
|
{
|
|
if (regno == 13) {
|
|
env->banked_r13[0] = val;
|
|
} else if (regno == 14) {
|
|
env->banked_r14[0] = val;
|
|
} else if (regno >= 8
|
|
&& (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
|
|
env->usr_regs[regno - 8] = val;
|
|
} else {
|
|
env->regs[regno] = val;
|
|
}
|
|
}
|
|
|
|
void HELPER(access_check_cp_reg)(CPUARMState *env, void *rip, uint32_t syndrome)
|
|
{
|
|
const ARMCPRegInfo *ri = rip;
|
|
int target_el;
|
|
|
|
if (arm_feature(env, ARM_FEATURE_XSCALE) && ri->cp < 14
|
|
&& extract32(env->cp15.c15_cpar, ri->cp, 1) == 0) {
|
|
raise_exception(env, EXCP_UDEF, syndrome, exception_target_el(env));
|
|
}
|
|
|
|
if (!ri->accessfn) {
|
|
return;
|
|
}
|
|
|
|
switch (ri->accessfn(env, ri)) {
|
|
case CP_ACCESS_OK:
|
|
return;
|
|
case CP_ACCESS_TRAP:
|
|
target_el = exception_target_el(env);
|
|
break;
|
|
case CP_ACCESS_TRAP_EL2:
|
|
/* Requesting a trap to EL2 when we're in EL3 or S-EL0/1 is
|
|
* a bug in the access function.
|
|
*/
|
|
assert(!arm_is_secure(env) && arm_current_el(env) != 3);
|
|
target_el = 2;
|
|
break;
|
|
case CP_ACCESS_TRAP_EL3:
|
|
target_el = 3;
|
|
break;
|
|
case CP_ACCESS_TRAP_UNCATEGORIZED:
|
|
target_el = exception_target_el(env);
|
|
syndrome = syn_uncategorized();
|
|
break;
|
|
default:
|
|
g_assert_not_reached();
|
|
}
|
|
|
|
raise_exception(env, EXCP_UDEF, syndrome, target_el);
|
|
}
|
|
|
|
void HELPER(set_cp_reg)(CPUARMState *env, void *rip, uint32_t value)
|
|
{
|
|
const ARMCPRegInfo *ri = rip;
|
|
|
|
ri->writefn(env, ri, value);
|
|
}
|
|
|
|
uint32_t HELPER(get_cp_reg)(CPUARMState *env, void *rip)
|
|
{
|
|
const ARMCPRegInfo *ri = rip;
|
|
|
|
return ri->readfn(env, ri);
|
|
}
|
|
|
|
void HELPER(set_cp_reg64)(CPUARMState *env, void *rip, uint64_t value)
|
|
{
|
|
const ARMCPRegInfo *ri = rip;
|
|
|
|
ri->writefn(env, ri, value);
|
|
}
|
|
|
|
uint64_t HELPER(get_cp_reg64)(CPUARMState *env, void *rip)
|
|
{
|
|
const ARMCPRegInfo *ri = rip;
|
|
|
|
return ri->readfn(env, ri);
|
|
}
|
|
|
|
void HELPER(msr_i_pstate)(CPUARMState *env, uint32_t op, uint32_t imm)
|
|
{
|
|
/* MSR_i to update PSTATE. This is OK from EL0 only if UMA is set.
|
|
* Note that SPSel is never OK from EL0; we rely on handle_msr_i()
|
|
* to catch that case at translate time.
|
|
*/
|
|
if (arm_current_el(env) == 0 && !(env->cp15.sctlr_el[1] & SCTLR_UMA)) {
|
|
uint32_t syndrome = syn_aa64_sysregtrap(0, extract32(op, 0, 3),
|
|
extract32(op, 3, 3), 4,
|
|
imm, 0x1f, 0);
|
|
raise_exception(env, EXCP_UDEF, syndrome, exception_target_el(env));
|
|
}
|
|
|
|
switch (op) {
|
|
case 0x05: /* SPSel */
|
|
update_spsel(env, imm);
|
|
break;
|
|
case 0x1e: /* DAIFSet */
|
|
env->daif |= (imm << 6) & PSTATE_DAIF;
|
|
break;
|
|
case 0x1f: /* DAIFClear */
|
|
env->daif &= ~((imm << 6) & PSTATE_DAIF);
|
|
break;
|
|
default:
|
|
g_assert_not_reached();
|
|
}
|
|
}
|
|
|
|
void HELPER(clear_pstate_ss)(CPUARMState *env)
|
|
{
|
|
env->pstate &= ~PSTATE_SS;
|
|
}
|
|
|
|
void HELPER(pre_hvc)(CPUARMState *env)
|
|
{
|
|
ARMCPU *cpu = arm_env_get_cpu(env);
|
|
int cur_el = arm_current_el(env);
|
|
/* FIXME: Use actual secure state. */
|
|
bool secure = false;
|
|
bool undef;
|
|
|
|
if (arm_is_psci_call(cpu, EXCP_HVC)) {
|
|
/* If PSCI is enabled and this looks like a valid PSCI call then
|
|
* that overrides the architecturally mandated HVC behaviour.
|
|
*/
|
|
return;
|
|
}
|
|
|
|
if (!arm_feature(env, ARM_FEATURE_EL2)) {
|
|
/* If EL2 doesn't exist, HVC always UNDEFs */
|
|
undef = true;
|
|
} else if (arm_feature(env, ARM_FEATURE_EL3)) {
|
|
/* EL3.HCE has priority over EL2.HCD. */
|
|
undef = !(env->cp15.scr_el3 & SCR_HCE);
|
|
} else {
|
|
undef = env->cp15.hcr_el2 & HCR_HCD;
|
|
}
|
|
|
|
/* In ARMv7 and ARMv8/AArch32, HVC is undef in secure state.
|
|
* For ARMv8/AArch64, HVC is allowed in EL3.
|
|
* Note that we've already trapped HVC from EL0 at translation
|
|
* time.
|
|
*/
|
|
if (secure && (!is_a64(env) || cur_el == 1)) {
|
|
undef = true;
|
|
}
|
|
|
|
if (undef) {
|
|
raise_exception(env, EXCP_UDEF, syn_uncategorized(),
|
|
exception_target_el(env));
|
|
}
|
|
}
|
|
|
|
void HELPER(pre_smc)(CPUARMState *env, uint32_t syndrome)
|
|
{
|
|
ARMCPU *cpu = arm_env_get_cpu(env);
|
|
int cur_el = arm_current_el(env);
|
|
bool secure = arm_is_secure(env);
|
|
bool smd = env->cp15.scr_el3 & SCR_SMD;
|
|
/* On ARMv8 AArch32, SMD only applies to NS state.
|
|
* On ARMv7 SMD only applies to NS state and only if EL2 is available.
|
|
* For ARMv7 non EL2, we force SMD to zero so we don't need to re-check
|
|
* the EL2 condition here.
|
|
*/
|
|
bool undef = is_a64(env) ? smd : (!secure && smd);
|
|
|
|
if (arm_is_psci_call(cpu, EXCP_SMC)) {
|
|
/* If PSCI is enabled and this looks like a valid PSCI call then
|
|
* that overrides the architecturally mandated SMC behaviour.
|
|
*/
|
|
return;
|
|
}
|
|
|
|
if (!arm_feature(env, ARM_FEATURE_EL3)) {
|
|
/* If we have no EL3 then SMC always UNDEFs */
|
|
undef = true;
|
|
} else if (!secure && cur_el == 1 && (env->cp15.hcr_el2 & HCR_TSC)) {
|
|
/* In NS EL1, HCR controlled routing to EL2 has priority over SMD. */
|
|
raise_exception(env, EXCP_HYP_TRAP, syndrome, 2);
|
|
}
|
|
|
|
if (undef) {
|
|
raise_exception(env, EXCP_UDEF, syn_uncategorized(),
|
|
exception_target_el(env));
|
|
}
|
|
}
|
|
|
|
void HELPER(exception_return)(CPUARMState *env)
|
|
{
|
|
int cur_el = arm_current_el(env);
|
|
unsigned int spsr_idx = aarch64_banked_spsr_index(cur_el);
|
|
uint32_t spsr = env->banked_spsr[spsr_idx];
|
|
int new_el;
|
|
|
|
aarch64_save_sp(env, cur_el);
|
|
|
|
env->exclusive_addr = -1;
|
|
|
|
/* We must squash the PSTATE.SS bit to zero unless both of the
|
|
* following hold:
|
|
* 1. debug exceptions are currently disabled
|
|
* 2. singlestep will be active in the EL we return to
|
|
* We check 1 here and 2 after we've done the pstate/cpsr write() to
|
|
* transition to the EL we're going to.
|
|
*/
|
|
if (arm_generate_debug_exceptions(env)) {
|
|
spsr &= ~PSTATE_SS;
|
|
}
|
|
|
|
if (spsr & PSTATE_nRW) {
|
|
/* TODO: We currently assume EL1/2/3 are running in AArch64. */
|
|
env->aarch64 = 0;
|
|
new_el = 0;
|
|
env->uncached_cpsr = 0x10;
|
|
cpsr_write(env, spsr, ~0);
|
|
if (!arm_singlestep_active(env)) {
|
|
env->uncached_cpsr &= ~PSTATE_SS;
|
|
}
|
|
aarch64_sync_64_to_32(env);
|
|
|
|
env->regs[15] = env->elr_el[1] & ~0x1;
|
|
} else {
|
|
new_el = extract32(spsr, 2, 2);
|
|
if (new_el > cur_el
|
|
|| (new_el == 2 && !arm_feature(env, ARM_FEATURE_EL2))) {
|
|
/* Disallow return to an EL which is unimplemented or higher
|
|
* than the current one.
|
|
*/
|
|
goto illegal_return;
|
|
}
|
|
if (extract32(spsr, 1, 1)) {
|
|
/* Return with reserved M[1] bit set */
|
|
goto illegal_return;
|
|
}
|
|
if (new_el == 0 && (spsr & PSTATE_SP)) {
|
|
/* Return to EL0 with M[0] bit set */
|
|
goto illegal_return;
|
|
}
|
|
env->aarch64 = 1;
|
|
pstate_write(env, spsr);
|
|
if (!arm_singlestep_active(env)) {
|
|
env->pstate &= ~PSTATE_SS;
|
|
}
|
|
aarch64_restore_sp(env, new_el);
|
|
env->pc = env->elr_el[cur_el];
|
|
}
|
|
|
|
return;
|
|
|
|
illegal_return:
|
|
/* Illegal return events of various kinds have architecturally
|
|
* mandated behaviour:
|
|
* restore NZCV and DAIF from SPSR_ELx
|
|
* set PSTATE.IL
|
|
* restore PC from ELR_ELx
|
|
* no change to exception level, execution state or stack pointer
|
|
*/
|
|
env->pstate |= PSTATE_IL;
|
|
env->pc = env->elr_el[cur_el];
|
|
spsr &= PSTATE_NZCV | PSTATE_DAIF;
|
|
spsr |= pstate_read(env) & ~(PSTATE_NZCV | PSTATE_DAIF);
|
|
pstate_write(env, spsr);
|
|
if (!arm_singlestep_active(env)) {
|
|
env->pstate &= ~PSTATE_SS;
|
|
}
|
|
}
|
|
|
|
/* Return true if the linked breakpoint entry lbn passes its checks */
|
|
static bool linked_bp_matches(ARMCPU *cpu, int lbn)
|
|
{
|
|
CPUARMState *env = &cpu->env;
|
|
uint64_t bcr = env->cp15.dbgbcr[lbn];
|
|
int brps = extract32(cpu->dbgdidr, 24, 4);
|
|
int ctx_cmps = extract32(cpu->dbgdidr, 20, 4);
|
|
int bt;
|
|
uint32_t contextidr;
|
|
|
|
/* Links to unimplemented or non-context aware breakpoints are
|
|
* CONSTRAINED UNPREDICTABLE: either behave as if disabled, or
|
|
* as if linked to an UNKNOWN context-aware breakpoint (in which
|
|
* case DBGWCR<n>_EL1.LBN must indicate that breakpoint).
|
|
* We choose the former.
|
|
*/
|
|
if (lbn > brps || lbn < (brps - ctx_cmps)) {
|
|
return false;
|
|
}
|
|
|
|
bcr = env->cp15.dbgbcr[lbn];
|
|
|
|
if (extract64(bcr, 0, 1) == 0) {
|
|
/* Linked breakpoint disabled : generate no events */
|
|
return false;
|
|
}
|
|
|
|
bt = extract64(bcr, 20, 4);
|
|
|
|
/* We match the whole register even if this is AArch32 using the
|
|
* short descriptor format (in which case it holds both PROCID and ASID),
|
|
* since we don't implement the optional v7 context ID masking.
|
|
*/
|
|
contextidr = extract64(env->cp15.contextidr_el[1], 0, 32);
|
|
|
|
switch (bt) {
|
|
case 3: /* linked context ID match */
|
|
if (arm_current_el(env) > 1) {
|
|
/* Context matches never fire in EL2 or (AArch64) EL3 */
|
|
return false;
|
|
}
|
|
return (contextidr == extract64(env->cp15.dbgbvr[lbn], 0, 32));
|
|
case 5: /* linked address mismatch (reserved in AArch64) */
|
|
case 9: /* linked VMID match (reserved if no EL2) */
|
|
case 11: /* linked context ID and VMID match (reserved if no EL2) */
|
|
default:
|
|
/* Links to Unlinked context breakpoints must generate no
|
|
* events; we choose to do the same for reserved values too.
|
|
*/
|
|
return false;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static bool bp_wp_matches(ARMCPU *cpu, int n, bool is_wp)
|
|
{
|
|
CPUARMState *env = &cpu->env;
|
|
uint64_t cr;
|
|
int pac, hmc, ssc, wt, lbn;
|
|
/* TODO: check against CPU security state when we implement TrustZone */
|
|
bool is_secure = false;
|
|
|
|
if (is_wp) {
|
|
if (!env->cpu_watchpoint[n]
|
|
|| !(env->cpu_watchpoint[n]->flags & BP_WATCHPOINT_HIT)) {
|
|
return false;
|
|
}
|
|
cr = env->cp15.dbgwcr[n];
|
|
} else {
|
|
uint64_t pc = is_a64(env) ? env->pc : env->regs[15];
|
|
|
|
if (!env->cpu_breakpoint[n] || env->cpu_breakpoint[n]->pc != pc) {
|
|
return false;
|
|
}
|
|
cr = env->cp15.dbgbcr[n];
|
|
}
|
|
/* The WATCHPOINT_HIT flag guarantees us that the watchpoint is
|
|
* enabled and that the address and access type match; for breakpoints
|
|
* we know the address matched; check the remaining fields, including
|
|
* linked breakpoints. We rely on WCR and BCR having the same layout
|
|
* for the LBN, SSC, HMC, PAC/PMC and is-linked fields.
|
|
* Note that some combinations of {PAC, HMC, SSC} are reserved and
|
|
* must act either like some valid combination or as if the watchpoint
|
|
* were disabled. We choose the former, and use this together with
|
|
* the fact that EL3 must always be Secure and EL2 must always be
|
|
* Non-Secure to simplify the code slightly compared to the full
|
|
* table in the ARM ARM.
|
|
*/
|
|
pac = extract64(cr, 1, 2);
|
|
hmc = extract64(cr, 13, 1);
|
|
ssc = extract64(cr, 14, 2);
|
|
|
|
switch (ssc) {
|
|
case 0:
|
|
break;
|
|
case 1:
|
|
case 3:
|
|
if (is_secure) {
|
|
return false;
|
|
}
|
|
break;
|
|
case 2:
|
|
if (!is_secure) {
|
|
return false;
|
|
}
|
|
break;
|
|
}
|
|
|
|
/* TODO: this is not strictly correct because the LDRT/STRT/LDT/STT
|
|
* "unprivileged access" instructions should match watchpoints as if
|
|
* they were accesses done at EL0, even if the CPU is at EL1 or higher.
|
|
* Implementing this would require reworking the core watchpoint code
|
|
* to plumb the mmu_idx through to this point. Luckily Linux does not
|
|
* rely on this behaviour currently.
|
|
* For breakpoints we do want to use the current CPU state.
|
|
*/
|
|
switch (arm_current_el(env)) {
|
|
case 3:
|
|
case 2:
|
|
if (!hmc) {
|
|
return false;
|
|
}
|
|
break;
|
|
case 1:
|
|
if (extract32(pac, 0, 1) == 0) {
|
|
return false;
|
|
}
|
|
break;
|
|
case 0:
|
|
if (extract32(pac, 1, 1) == 0) {
|
|
return false;
|
|
}
|
|
break;
|
|
default:
|
|
g_assert_not_reached();
|
|
}
|
|
|
|
wt = extract64(cr, 20, 1);
|
|
lbn = extract64(cr, 16, 4);
|
|
|
|
if (wt && !linked_bp_matches(cpu, lbn)) {
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool check_watchpoints(ARMCPU *cpu)
|
|
{
|
|
CPUARMState *env = &cpu->env;
|
|
int n;
|
|
|
|
/* If watchpoints are disabled globally or we can't take debug
|
|
* exceptions here then watchpoint firings are ignored.
|
|
*/
|
|
if (extract32(env->cp15.mdscr_el1, 15, 1) == 0
|
|
|| !arm_generate_debug_exceptions(env)) {
|
|
return false;
|
|
}
|
|
|
|
for (n = 0; n < ARRAY_SIZE(env->cpu_watchpoint); n++) {
|
|
if (bp_wp_matches(cpu, n, true)) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool check_breakpoints(ARMCPU *cpu)
|
|
{
|
|
CPUARMState *env = &cpu->env;
|
|
int n;
|
|
|
|
/* If breakpoints are disabled globally or we can't take debug
|
|
* exceptions here then breakpoint firings are ignored.
|
|
*/
|
|
if (extract32(env->cp15.mdscr_el1, 15, 1) == 0
|
|
|| !arm_generate_debug_exceptions(env)) {
|
|
return false;
|
|
}
|
|
|
|
for (n = 0; n < ARRAY_SIZE(env->cpu_breakpoint); n++) {
|
|
if (bp_wp_matches(cpu, n, false)) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
void arm_debug_excp_handler(CPUState *cs)
|
|
{
|
|
/* Called by core code when a watchpoint or breakpoint fires;
|
|
* need to check which one and raise the appropriate exception.
|
|
*/
|
|
ARMCPU *cpu = ARM_CPU(cs->uc, cs);
|
|
CPUARMState *env = &cpu->env;
|
|
CPUWatchpoint *wp_hit = cs->watchpoint_hit;
|
|
|
|
if (wp_hit) {
|
|
if (wp_hit->flags & BP_CPU) {
|
|
cs->watchpoint_hit = NULL;
|
|
if (check_watchpoints(cpu)) {
|
|
bool wnr = (wp_hit->flags & BP_WATCHPOINT_HIT_WRITE) != 0;
|
|
bool same_el = arm_debug_target_el(env) == arm_current_el(env);
|
|
|
|
if (extended_addresses_enabled(env)) {
|
|
env->exception.fsr = (1 << 9) | 0x22;
|
|
} else {
|
|
env->exception.fsr = 0x2;
|
|
}
|
|
env->exception.vaddress = wp_hit->hitaddr;
|
|
raise_exception(env, EXCP_DATA_ABORT,
|
|
syn_watchpoint(same_el, 0, wnr),
|
|
arm_debug_target_el(env));
|
|
} else {
|
|
cpu_resume_from_signal(cs, NULL);
|
|
}
|
|
}
|
|
} else {
|
|
if (check_breakpoints(cpu)) {
|
|
bool same_el = (arm_debug_target_el(env) == arm_current_el(env));
|
|
if (extended_addresses_enabled(env)) {
|
|
env->exception.fsr = (1 << 9) | 0x22;
|
|
} else {
|
|
env->exception.fsr = 0x2;
|
|
}
|
|
/* FAR is UNKNOWN, so doesn't need setting */
|
|
raise_exception(env, EXCP_PREFETCH_ABORT,
|
|
syn_breakpoint(same_el),
|
|
arm_debug_target_el(env));
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ??? Flag setting arithmetic is awkward because we need to do comparisons.
|
|
The only way to do that in TCG is a conditional branch, which clobbers
|
|
all our temporaries. For now implement these as helper functions. */
|
|
|
|
/* Similarly for variable shift instructions. */
|
|
|
|
uint32_t HELPER(shl_cc)(CPUARMState *env, uint32_t x, uint32_t i)
|
|
{
|
|
int shift = i & 0xff;
|
|
if (shift >= 32) {
|
|
if (shift == 32)
|
|
env->CF = x & 1;
|
|
else
|
|
env->CF = 0;
|
|
return 0;
|
|
} else if (shift != 0) {
|
|
env->CF = (x >> (32 - shift)) & 1;
|
|
return x << shift;
|
|
}
|
|
return x;
|
|
}
|
|
|
|
uint32_t HELPER(shr_cc)(CPUARMState *env, uint32_t x, uint32_t i)
|
|
{
|
|
int shift = i & 0xff;
|
|
if (shift >= 32) {
|
|
if (shift == 32)
|
|
env->CF = (x >> 31) & 1;
|
|
else
|
|
env->CF = 0;
|
|
return 0;
|
|
} else if (shift != 0) {
|
|
env->CF = (x >> (shift - 1)) & 1;
|
|
return x >> shift;
|
|
}
|
|
return x;
|
|
}
|
|
|
|
uint32_t HELPER(sar_cc)(CPUARMState *env, uint32_t x, uint32_t i)
|
|
{
|
|
int shift = i & 0xff;
|
|
if (shift >= 32) {
|
|
env->CF = (x >> 31) & 1;
|
|
return (int32_t)x >> 31;
|
|
} else if (shift != 0) {
|
|
env->CF = (x >> (shift - 1)) & 1;
|
|
return (int32_t)x >> shift;
|
|
}
|
|
return x;
|
|
}
|
|
|
|
uint32_t HELPER(ror_cc)(CPUARMState *env, uint32_t x, uint32_t i)
|
|
{
|
|
int shift1, shift;
|
|
shift1 = i & 0xff;
|
|
shift = shift1 & 0x1f;
|
|
if (shift == 0) {
|
|
if (shift1 != 0)
|
|
env->CF = (x >> 31) & 1;
|
|
return x;
|
|
} else {
|
|
env->CF = (x >> (shift - 1)) & 1;
|
|
return ((uint32_t)x >> shift) | (x << (32 - shift));
|
|
}
|
|
}
|