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qemu/target/arm/tcg/helper-a64.c
Peter Maydell 35aa6715dd target/arm: Catch illegal-exception-return from EL3 with bad NSE/NS 
The architecture requires (R_TYTWB) that an attempt to return from EL3
when SCR_EL3.{NSE,NS} are {1,0} is an illegal exception return. (This
enforces that the CPU can't ever be executing below EL3 with the
NSE,NS bits indicating an invalid security state.)

We were missing this check; add it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230807150618.101357-1-peter.maydell@linaro.org
2023-08-31 09:45:17 +01:00

971 lines
28 KiB
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/*
* AArch64 specific helpers
*
* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
*
* 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 2.1 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 "qemu/units.h"
#include "cpu.h"
#include "gdbstub/helpers.h"
#include "exec/helper-proto.h"
#include "qemu/host-utils.h"
#include "qemu/log.h"
#include "qemu/main-loop.h"
#include "qemu/bitops.h"
#include "internals.h"
#include "qemu/crc32c.h"
#include "exec/exec-all.h"
#include "exec/cpu_ldst.h"
#include "qemu/int128.h"
#include "qemu/atomic128.h"
#include "fpu/softfloat.h"
#include <zlib.h> /* For crc32 */
/* C2.4.7 Multiply and divide */
/* special cases for 0 and LLONG_MIN are mandated by the standard */
uint64_t HELPER(udiv64)(uint64_t num, uint64_t den)
{
if (den == 0) {
return 0;
}
return num / den;
}
int64_t HELPER(sdiv64)(int64_t num, int64_t den)
{
if (den == 0) {
return 0;
}
if (num == LLONG_MIN && den == -1) {
return LLONG_MIN;
}
return num / den;
}
uint64_t HELPER(rbit64)(uint64_t x)
{
return revbit64(x);
}
void HELPER(msr_i_spsel)(CPUARMState *env, uint32_t imm)
{
update_spsel(env, imm);
}
static void daif_check(CPUARMState *env, uint32_t op,
uint32_t imm, uintptr_t ra)
{
/* DAIF update to PSTATE. This is OK from EL0 only if UMA is set. */
if (arm_current_el(env) == 0 && !(arm_sctlr(env, 0) & SCTLR_UMA)) {
raise_exception_ra(env, EXCP_UDEF,
syn_aa64_sysregtrap(0, extract32(op, 0, 3),
extract32(op, 3, 3), 4,
imm, 0x1f, 0),
exception_target_el(env), ra);
}
}
void HELPER(msr_i_daifset)(CPUARMState *env, uint32_t imm)
{
daif_check(env, 0x1e, imm, GETPC());
env->daif |= (imm << 6) & PSTATE_DAIF;
arm_rebuild_hflags(env);
}
void HELPER(msr_i_daifclear)(CPUARMState *env, uint32_t imm)
{
daif_check(env, 0x1f, imm, GETPC());
env->daif &= ~((imm << 6) & PSTATE_DAIF);
arm_rebuild_hflags(env);
}
/* Convert a softfloat float_relation_ (as returned by
* the float*_compare functions) to the correct ARM
* NZCV flag state.
*/
static inline uint32_t float_rel_to_flags(int res)
{
uint64_t flags;
switch (res) {
case float_relation_equal:
flags = PSTATE_Z | PSTATE_C;
break;
case float_relation_less:
flags = PSTATE_N;
break;
case float_relation_greater:
flags = PSTATE_C;
break;
case float_relation_unordered:
default:
flags = PSTATE_C | PSTATE_V;
break;
}
return flags;
}
uint64_t HELPER(vfp_cmph_a64)(uint32_t x, uint32_t y, void *fp_status)
{
return float_rel_to_flags(float16_compare_quiet(x, y, fp_status));
}
uint64_t HELPER(vfp_cmpeh_a64)(uint32_t x, uint32_t y, void *fp_status)
{
return float_rel_to_flags(float16_compare(x, y, fp_status));
}
uint64_t HELPER(vfp_cmps_a64)(float32 x, float32 y, void *fp_status)
{
return float_rel_to_flags(float32_compare_quiet(x, y, fp_status));
}
uint64_t HELPER(vfp_cmpes_a64)(float32 x, float32 y, void *fp_status)
{
return float_rel_to_flags(float32_compare(x, y, fp_status));
}
uint64_t HELPER(vfp_cmpd_a64)(float64 x, float64 y, void *fp_status)
{
return float_rel_to_flags(float64_compare_quiet(x, y, fp_status));
}
uint64_t HELPER(vfp_cmped_a64)(float64 x, float64 y, void *fp_status)
{
return float_rel_to_flags(float64_compare(x, y, fp_status));
}
float32 HELPER(vfp_mulxs)(float32 a, float32 b, void *fpstp)
{
float_status *fpst = fpstp;
a = float32_squash_input_denormal(a, fpst);
b = float32_squash_input_denormal(b, fpst);
if ((float32_is_zero(a) && float32_is_infinity(b)) ||
(float32_is_infinity(a) && float32_is_zero(b))) {
/* 2.0 with the sign bit set to sign(A) XOR sign(B) */
return make_float32((1U << 30) |
((float32_val(a) ^ float32_val(b)) & (1U << 31)));
}
return float32_mul(a, b, fpst);
}
float64 HELPER(vfp_mulxd)(float64 a, float64 b, void *fpstp)
{
float_status *fpst = fpstp;
a = float64_squash_input_denormal(a, fpst);
b = float64_squash_input_denormal(b, fpst);
if ((float64_is_zero(a) && float64_is_infinity(b)) ||
(float64_is_infinity(a) && float64_is_zero(b))) {
/* 2.0 with the sign bit set to sign(A) XOR sign(B) */
return make_float64((1ULL << 62) |
((float64_val(a) ^ float64_val(b)) & (1ULL << 63)));
}
return float64_mul(a, b, fpst);
}
/* 64bit/double versions of the neon float compare functions */
uint64_t HELPER(neon_ceq_f64)(float64 a, float64 b, void *fpstp)
{
float_status *fpst = fpstp;
return -float64_eq_quiet(a, b, fpst);
}
uint64_t HELPER(neon_cge_f64)(float64 a, float64 b, void *fpstp)
{
float_status *fpst = fpstp;
return -float64_le(b, a, fpst);
}
uint64_t HELPER(neon_cgt_f64)(float64 a, float64 b, void *fpstp)
{
float_status *fpst = fpstp;
return -float64_lt(b, a, fpst);
}
/* Reciprocal step and sqrt step. Note that unlike the A32/T32
* versions, these do a fully fused multiply-add or
* multiply-add-and-halve.
*/
uint32_t HELPER(recpsf_f16)(uint32_t a, uint32_t b, void *fpstp)
{
float_status *fpst = fpstp;
a = float16_squash_input_denormal(a, fpst);
b = float16_squash_input_denormal(b, fpst);
a = float16_chs(a);
if ((float16_is_infinity(a) && float16_is_zero(b)) ||
(float16_is_infinity(b) && float16_is_zero(a))) {
return float16_two;
}
return float16_muladd(a, b, float16_two, 0, fpst);
}
float32 HELPER(recpsf_f32)(float32 a, float32 b, void *fpstp)
{
float_status *fpst = fpstp;
a = float32_squash_input_denormal(a, fpst);
b = float32_squash_input_denormal(b, fpst);
a = float32_chs(a);
if ((float32_is_infinity(a) && float32_is_zero(b)) ||
(float32_is_infinity(b) && float32_is_zero(a))) {
return float32_two;
}
return float32_muladd(a, b, float32_two, 0, fpst);
}
float64 HELPER(recpsf_f64)(float64 a, float64 b, void *fpstp)
{
float_status *fpst = fpstp;
a = float64_squash_input_denormal(a, fpst);
b = float64_squash_input_denormal(b, fpst);
a = float64_chs(a);
if ((float64_is_infinity(a) && float64_is_zero(b)) ||
(float64_is_infinity(b) && float64_is_zero(a))) {
return float64_two;
}
return float64_muladd(a, b, float64_two, 0, fpst);
}
uint32_t HELPER(rsqrtsf_f16)(uint32_t a, uint32_t b, void *fpstp)
{
float_status *fpst = fpstp;
a = float16_squash_input_denormal(a, fpst);
b = float16_squash_input_denormal(b, fpst);
a = float16_chs(a);
if ((float16_is_infinity(a) && float16_is_zero(b)) ||
(float16_is_infinity(b) && float16_is_zero(a))) {
return float16_one_point_five;
}
return float16_muladd(a, b, float16_three, float_muladd_halve_result, fpst);
}
float32 HELPER(rsqrtsf_f32)(float32 a, float32 b, void *fpstp)
{
float_status *fpst = fpstp;
a = float32_squash_input_denormal(a, fpst);
b = float32_squash_input_denormal(b, fpst);
a = float32_chs(a);
if ((float32_is_infinity(a) && float32_is_zero(b)) ||
(float32_is_infinity(b) && float32_is_zero(a))) {
return float32_one_point_five;
}
return float32_muladd(a, b, float32_three, float_muladd_halve_result, fpst);
}
float64 HELPER(rsqrtsf_f64)(float64 a, float64 b, void *fpstp)
{
float_status *fpst = fpstp;
a = float64_squash_input_denormal(a, fpst);
b = float64_squash_input_denormal(b, fpst);
a = float64_chs(a);
if ((float64_is_infinity(a) && float64_is_zero(b)) ||
(float64_is_infinity(b) && float64_is_zero(a))) {
return float64_one_point_five;
}
return float64_muladd(a, b, float64_three, float_muladd_halve_result, fpst);
}
/* Pairwise long add: add pairs of adjacent elements into
* double-width elements in the result (eg _s8 is an 8x8->16 op)
*/
uint64_t HELPER(neon_addlp_s8)(uint64_t a)
{
uint64_t nsignmask = 0x0080008000800080ULL;
uint64_t wsignmask = 0x8000800080008000ULL;
uint64_t elementmask = 0x00ff00ff00ff00ffULL;
uint64_t tmp1, tmp2;
uint64_t res, signres;
/* Extract odd elements, sign extend each to a 16 bit field */
tmp1 = a & elementmask;
tmp1 ^= nsignmask;
tmp1 |= wsignmask;
tmp1 = (tmp1 - nsignmask) ^ wsignmask;
/* Ditto for the even elements */
tmp2 = (a >> 8) & elementmask;
tmp2 ^= nsignmask;
tmp2 |= wsignmask;
tmp2 = (tmp2 - nsignmask) ^ wsignmask;
/* calculate the result by summing bits 0..14, 16..22, etc,
* and then adjusting the sign bits 15, 23, etc manually.
* This ensures the addition can't overflow the 16 bit field.
*/
signres = (tmp1 ^ tmp2) & wsignmask;
res = (tmp1 & ~wsignmask) + (tmp2 & ~wsignmask);
res ^= signres;
return res;
}
uint64_t HELPER(neon_addlp_u8)(uint64_t a)
{
uint64_t tmp;
tmp = a & 0x00ff00ff00ff00ffULL;
tmp += (a >> 8) & 0x00ff00ff00ff00ffULL;
return tmp;
}
uint64_t HELPER(neon_addlp_s16)(uint64_t a)
{
int32_t reslo, reshi;
reslo = (int32_t)(int16_t)a + (int32_t)(int16_t)(a >> 16);
reshi = (int32_t)(int16_t)(a >> 32) + (int32_t)(int16_t)(a >> 48);
return (uint32_t)reslo | (((uint64_t)reshi) << 32);
}
uint64_t HELPER(neon_addlp_u16)(uint64_t a)
{
uint64_t tmp;
tmp = a & 0x0000ffff0000ffffULL;
tmp += (a >> 16) & 0x0000ffff0000ffffULL;
return tmp;
}
/* Floating-point reciprocal exponent - see FPRecpX in ARM ARM */
uint32_t HELPER(frecpx_f16)(uint32_t a, void *fpstp)
{
float_status *fpst = fpstp;
uint16_t val16, sbit;
int16_t exp;
if (float16_is_any_nan(a)) {
float16 nan = a;
if (float16_is_signaling_nan(a, fpst)) {
float_raise(float_flag_invalid, fpst);
if (!fpst->default_nan_mode) {
nan = float16_silence_nan(a, fpst);
}
}
if (fpst->default_nan_mode) {
nan = float16_default_nan(fpst);
}
return nan;
}
a = float16_squash_input_denormal(a, fpst);
val16 = float16_val(a);
sbit = 0x8000 & val16;
exp = extract32(val16, 10, 5);
if (exp == 0) {
return make_float16(deposit32(sbit, 10, 5, 0x1e));
} else {
return make_float16(deposit32(sbit, 10, 5, ~exp));
}
}
float32 HELPER(frecpx_f32)(float32 a, void *fpstp)
{
float_status *fpst = fpstp;
uint32_t val32, sbit;
int32_t exp;
if (float32_is_any_nan(a)) {
float32 nan = a;
if (float32_is_signaling_nan(a, fpst)) {
float_raise(float_flag_invalid, fpst);
if (!fpst->default_nan_mode) {
nan = float32_silence_nan(a, fpst);
}
}
if (fpst->default_nan_mode) {
nan = float32_default_nan(fpst);
}
return nan;
}
a = float32_squash_input_denormal(a, fpst);
val32 = float32_val(a);
sbit = 0x80000000ULL & val32;
exp = extract32(val32, 23, 8);
if (exp == 0) {
return make_float32(sbit | (0xfe << 23));
} else {
return make_float32(sbit | (~exp & 0xff) << 23);
}
}
float64 HELPER(frecpx_f64)(float64 a, void *fpstp)
{
float_status *fpst = fpstp;
uint64_t val64, sbit;
int64_t exp;
if (float64_is_any_nan(a)) {
float64 nan = a;
if (float64_is_signaling_nan(a, fpst)) {
float_raise(float_flag_invalid, fpst);
if (!fpst->default_nan_mode) {
nan = float64_silence_nan(a, fpst);
}
}
if (fpst->default_nan_mode) {
nan = float64_default_nan(fpst);
}
return nan;
}
a = float64_squash_input_denormal(a, fpst);
val64 = float64_val(a);
sbit = 0x8000000000000000ULL & val64;
exp = extract64(float64_val(a), 52, 11);
if (exp == 0) {
return make_float64(sbit | (0x7feULL << 52));
} else {
return make_float64(sbit | (~exp & 0x7ffULL) << 52);
}
}
float32 HELPER(fcvtx_f64_to_f32)(float64 a, CPUARMState *env)
{
/* Von Neumann rounding is implemented by using round-to-zero
* and then setting the LSB of the result if Inexact was raised.
*/
float32 r;
float_status *fpst = &env->vfp.fp_status;
float_status tstat = *fpst;
int exflags;
set_float_rounding_mode(float_round_to_zero, &tstat);
set_float_exception_flags(0, &tstat);
r = float64_to_float32(a, &tstat);
exflags = get_float_exception_flags(&tstat);
if (exflags & float_flag_inexact) {
r = make_float32(float32_val(r) | 1);
}
exflags |= get_float_exception_flags(fpst);
set_float_exception_flags(exflags, fpst);
return r;
}
/* 64-bit versions of the CRC helpers. Note that although the operation
* (and the prototypes of crc32c() and crc32() mean that only the bottom
* 32 bits of the accumulator and result are used, we pass and return
* uint64_t for convenience of the generated code. Unlike the 32-bit
* instruction set versions, val may genuinely have 64 bits of data in it.
* The upper bytes of val (above the number specified by 'bytes') must have
* been zeroed out by the caller.
*/
uint64_t HELPER(crc32_64)(uint64_t acc, uint64_t val, uint32_t bytes)
{
uint8_t buf[8];
stq_le_p(buf, val);
/* zlib crc32 converts the accumulator and output to one's complement. */
return crc32(acc ^ 0xffffffff, buf, bytes) ^ 0xffffffff;
}
uint64_t HELPER(crc32c_64)(uint64_t acc, uint64_t val, uint32_t bytes)
{
uint8_t buf[8];
stq_le_p(buf, val);
/* Linux crc32c converts the output to one's complement. */
return crc32c(acc, buf, bytes) ^ 0xffffffff;
}
/*
* AdvSIMD half-precision
*/
#define ADVSIMD_HELPER(name, suffix) HELPER(glue(glue(advsimd_, name), suffix))
#define ADVSIMD_HALFOP(name) \
uint32_t ADVSIMD_HELPER(name, h)(uint32_t a, uint32_t b, void *fpstp) \
{ \
float_status *fpst = fpstp; \
return float16_ ## name(a, b, fpst); \
}
ADVSIMD_HALFOP(add)
ADVSIMD_HALFOP(sub)
ADVSIMD_HALFOP(mul)
ADVSIMD_HALFOP(div)
ADVSIMD_HALFOP(min)
ADVSIMD_HALFOP(max)
ADVSIMD_HALFOP(minnum)
ADVSIMD_HALFOP(maxnum)
#define ADVSIMD_TWOHALFOP(name) \
uint32_t ADVSIMD_HELPER(name, 2h)(uint32_t two_a, uint32_t two_b, void *fpstp) \
{ \
float16 a1, a2, b1, b2; \
uint32_t r1, r2; \
float_status *fpst = fpstp; \
a1 = extract32(two_a, 0, 16); \
a2 = extract32(two_a, 16, 16); \
b1 = extract32(two_b, 0, 16); \
b2 = extract32(two_b, 16, 16); \
r1 = float16_ ## name(a1, b1, fpst); \
r2 = float16_ ## name(a2, b2, fpst); \
return deposit32(r1, 16, 16, r2); \
}
ADVSIMD_TWOHALFOP(add)
ADVSIMD_TWOHALFOP(sub)
ADVSIMD_TWOHALFOP(mul)
ADVSIMD_TWOHALFOP(div)
ADVSIMD_TWOHALFOP(min)
ADVSIMD_TWOHALFOP(max)
ADVSIMD_TWOHALFOP(minnum)
ADVSIMD_TWOHALFOP(maxnum)
/* Data processing - scalar floating-point and advanced SIMD */
static float16 float16_mulx(float16 a, float16 b, void *fpstp)
{
float_status *fpst = fpstp;
a = float16_squash_input_denormal(a, fpst);
b = float16_squash_input_denormal(b, fpst);
if ((float16_is_zero(a) && float16_is_infinity(b)) ||
(float16_is_infinity(a) && float16_is_zero(b))) {
/* 2.0 with the sign bit set to sign(A) XOR sign(B) */
return make_float16((1U << 14) |
((float16_val(a) ^ float16_val(b)) & (1U << 15)));
}
return float16_mul(a, b, fpst);
}
ADVSIMD_HALFOP(mulx)
ADVSIMD_TWOHALFOP(mulx)
/* fused multiply-accumulate */
uint32_t HELPER(advsimd_muladdh)(uint32_t a, uint32_t b, uint32_t c,
void *fpstp)
{
float_status *fpst = fpstp;
return float16_muladd(a, b, c, 0, fpst);
}
uint32_t HELPER(advsimd_muladd2h)(uint32_t two_a, uint32_t two_b,
uint32_t two_c, void *fpstp)
{
float_status *fpst = fpstp;
float16 a1, a2, b1, b2, c1, c2;
uint32_t r1, r2;
a1 = extract32(two_a, 0, 16);
a2 = extract32(two_a, 16, 16);
b1 = extract32(two_b, 0, 16);
b2 = extract32(two_b, 16, 16);
c1 = extract32(two_c, 0, 16);
c2 = extract32(two_c, 16, 16);
r1 = float16_muladd(a1, b1, c1, 0, fpst);
r2 = float16_muladd(a2, b2, c2, 0, fpst);
return deposit32(r1, 16, 16, r2);
}
/*
* Floating point comparisons produce an integer result. Softfloat
* routines return float_relation types which we convert to the 0/-1
* Neon requires.
*/
#define ADVSIMD_CMPRES(test) (test) ? 0xffff : 0
uint32_t HELPER(advsimd_ceq_f16)(uint32_t a, uint32_t b, void *fpstp)
{
float_status *fpst = fpstp;
int compare = float16_compare_quiet(a, b, fpst);
return ADVSIMD_CMPRES(compare == float_relation_equal);
}
uint32_t HELPER(advsimd_cge_f16)(uint32_t a, uint32_t b, void *fpstp)
{
float_status *fpst = fpstp;
int compare = float16_compare(a, b, fpst);
return ADVSIMD_CMPRES(compare == float_relation_greater ||
compare == float_relation_equal);
}
uint32_t HELPER(advsimd_cgt_f16)(uint32_t a, uint32_t b, void *fpstp)
{
float_status *fpst = fpstp;
int compare = float16_compare(a, b, fpst);
return ADVSIMD_CMPRES(compare == float_relation_greater);
}
uint32_t HELPER(advsimd_acge_f16)(uint32_t a, uint32_t b, void *fpstp)
{
float_status *fpst = fpstp;
float16 f0 = float16_abs(a);
float16 f1 = float16_abs(b);
int compare = float16_compare(f0, f1, fpst);
return ADVSIMD_CMPRES(compare == float_relation_greater ||
compare == float_relation_equal);
}
uint32_t HELPER(advsimd_acgt_f16)(uint32_t a, uint32_t b, void *fpstp)
{
float_status *fpst = fpstp;
float16 f0 = float16_abs(a);
float16 f1 = float16_abs(b);
int compare = float16_compare(f0, f1, fpst);
return ADVSIMD_CMPRES(compare == float_relation_greater);
}
/* round to integral */
uint32_t HELPER(advsimd_rinth_exact)(uint32_t x, void *fp_status)
{
return float16_round_to_int(x, fp_status);
}
uint32_t HELPER(advsimd_rinth)(uint32_t x, void *fp_status)
{
int old_flags = get_float_exception_flags(fp_status), new_flags;
float16 ret;
ret = float16_round_to_int(x, fp_status);
/* Suppress any inexact exceptions the conversion produced */
if (!(old_flags & float_flag_inexact)) {
new_flags = get_float_exception_flags(fp_status);
set_float_exception_flags(new_flags & ~float_flag_inexact, fp_status);
}
return ret;
}
/*
* Half-precision floating point conversion functions
*
* There are a multitude of conversion functions with various
* different rounding modes. This is dealt with by the calling code
* setting the mode appropriately before calling the helper.
*/
uint32_t HELPER(advsimd_f16tosinth)(uint32_t a, void *fpstp)
{
float_status *fpst = fpstp;
/* Invalid if we are passed a NaN */
if (float16_is_any_nan(a)) {
float_raise(float_flag_invalid, fpst);
return 0;
}
return float16_to_int16(a, fpst);
}
uint32_t HELPER(advsimd_f16touinth)(uint32_t a, void *fpstp)
{
float_status *fpst = fpstp;
/* Invalid if we are passed a NaN */
if (float16_is_any_nan(a)) {
float_raise(float_flag_invalid, fpst);
return 0;
}
return float16_to_uint16(a, fpst);
}
static int el_from_spsr(uint32_t spsr)
{
/* Return the exception level that this SPSR is requesting a return to,
* or -1 if it is invalid (an illegal return)
*/
if (spsr & PSTATE_nRW) {
switch (spsr & CPSR_M) {
case ARM_CPU_MODE_USR:
return 0;
case ARM_CPU_MODE_HYP:
return 2;
case ARM_CPU_MODE_FIQ:
case ARM_CPU_MODE_IRQ:
case ARM_CPU_MODE_SVC:
case ARM_CPU_MODE_ABT:
case ARM_CPU_MODE_UND:
case ARM_CPU_MODE_SYS:
return 1;
case ARM_CPU_MODE_MON:
/* Returning to Mon from AArch64 is never possible,
* so this is an illegal return.
*/
default:
return -1;
}
} else {
if (extract32(spsr, 1, 1)) {
/* Return with reserved M[1] bit set */
return -1;
}
if (extract32(spsr, 0, 4) == 1) {
/* return to EL0 with M[0] bit set */
return -1;
}
return extract32(spsr, 2, 2);
}
}
static void cpsr_write_from_spsr_elx(CPUARMState *env,
uint32_t val)
{
uint32_t mask;
/* Save SPSR_ELx.SS into PSTATE. */
env->pstate = (env->pstate & ~PSTATE_SS) | (val & PSTATE_SS);
val &= ~PSTATE_SS;
/* Move DIT to the correct location for CPSR */
if (val & PSTATE_DIT) {
val &= ~PSTATE_DIT;
val |= CPSR_DIT;
}
mask = aarch32_cpsr_valid_mask(env->features, \
&env_archcpu(env)->isar);
cpsr_write(env, val, mask, CPSRWriteRaw);
}
void HELPER(exception_return)(CPUARMState *env, uint64_t new_pc)
{
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;
bool return_to_aa64 = (spsr & PSTATE_nRW) == 0;
aarch64_save_sp(env, cur_el);
arm_clear_exclusive(env);
/* 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;
}
/*
* FEAT_RME forbids return from EL3 with an invalid security state.
* We don't need an explicit check for FEAT_RME here because we enforce
* in scr_write() that you can't set the NSE bit without it.
*/
if (cur_el == 3 && (env->cp15.scr_el3 & (SCR_NS | SCR_NSE)) == SCR_NSE) {
goto illegal_return;
}
new_el = el_from_spsr(spsr);
if (new_el == -1) {
goto illegal_return;
}
if (new_el > cur_el || (new_el == 2 && !arm_is_el2_enabled(env))) {
/* Disallow return to an EL which is unimplemented or higher
* than the current one.
*/
goto illegal_return;
}
if (new_el != 0 && arm_el_is_aa64(env, new_el) != return_to_aa64) {
/* Return to an EL which is configured for a different register width */
goto illegal_return;
}
if (new_el == 1 && (arm_hcr_el2_eff(env) & HCR_TGE)) {
goto illegal_return;
}
qemu_mutex_lock_iothread();
arm_call_pre_el_change_hook(env_archcpu(env));
qemu_mutex_unlock_iothread();
if (!return_to_aa64) {
env->aarch64 = false;
/* We do a raw CPSR write because aarch64_sync_64_to_32()
* will sort the register banks out for us, and we've already
* caught all the bad-mode cases in el_from_spsr().
*/
cpsr_write_from_spsr_elx(env, spsr);
if (!arm_singlestep_active(env)) {
env->pstate &= ~PSTATE_SS;
}
aarch64_sync_64_to_32(env);
if (spsr & CPSR_T) {
env->regs[15] = new_pc & ~0x1;
} else {
env->regs[15] = new_pc & ~0x3;
}
helper_rebuild_hflags_a32(env, new_el);
qemu_log_mask(CPU_LOG_INT, "Exception return from AArch64 EL%d to "
"AArch32 EL%d PC 0x%" PRIx32 "\n",
cur_el, new_el, env->regs[15]);
} else {
int tbii;
env->aarch64 = true;
spsr &= aarch64_pstate_valid_mask(&env_archcpu(env)->isar);
pstate_write(env, spsr);
if (!arm_singlestep_active(env)) {
env->pstate &= ~PSTATE_SS;
}
aarch64_restore_sp(env, new_el);
helper_rebuild_hflags_a64(env, new_el);
/*
* Apply TBI to the exception return address. We had to delay this
* until after we selected the new EL, so that we could select the
* correct TBI+TBID bits. This is made easier by waiting until after
* the hflags rebuild, since we can pull the composite TBII field
* from there.
*/
tbii = EX_TBFLAG_A64(env->hflags, TBII);
if ((tbii >> extract64(new_pc, 55, 1)) & 1) {
/* TBI is enabled. */
int core_mmu_idx = cpu_mmu_index(env, false);
if (regime_has_2_ranges(core_to_aa64_mmu_idx(core_mmu_idx))) {
new_pc = sextract64(new_pc, 0, 56);
} else {
new_pc = extract64(new_pc, 0, 56);
}
}
env->pc = new_pc;
qemu_log_mask(CPU_LOG_INT, "Exception return from AArch64 EL%d to "
"AArch64 EL%d PC 0x%" PRIx64 "\n",
cur_el, new_el, env->pc);
}
/*
* Note that cur_el can never be 0. If new_el is 0, then
* el0_a64 is return_to_aa64, else el0_a64 is ignored.
*/
aarch64_sve_change_el(env, cur_el, new_el, return_to_aa64);
qemu_mutex_lock_iothread();
arm_call_el_change_hook(env_archcpu(env));
qemu_mutex_unlock_iothread();
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 = new_pc;
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;
}
helper_rebuild_hflags_a64(env, cur_el);
qemu_log_mask(LOG_GUEST_ERROR, "Illegal exception return at EL%d: "
"resuming execution at 0x%" PRIx64 "\n", cur_el, env->pc);
}
/*
* Square Root and Reciprocal square root
*/
uint32_t HELPER(sqrt_f16)(uint32_t a, void *fpstp)
{
float_status *s = fpstp;
return float16_sqrt(a, s);
}
void HELPER(dc_zva)(CPUARMState *env, uint64_t vaddr_in)
{
/*
* Implement DC ZVA, which zeroes a fixed-length block of memory.
* Note that we do not implement the (architecturally mandated)
* alignment fault for attempts to use this on Device memory
* (which matches the usual QEMU behaviour of not implementing either
* alignment faults or any memory attribute handling).
*/
int blocklen = 4 << env_archcpu(env)->dcz_blocksize;
uint64_t vaddr = vaddr_in & ~(blocklen - 1);
int mmu_idx = cpu_mmu_index(env, false);
void *mem;
/*
* Trapless lookup. In addition to actual invalid page, may
* return NULL for I/O, watchpoints, clean pages, etc.
*/
mem = tlb_vaddr_to_host(env, vaddr, MMU_DATA_STORE, mmu_idx);
#ifndef CONFIG_USER_ONLY
if (unlikely(!mem)) {
uintptr_t ra = GETPC();
/*
* Trap if accessing an invalid page. DC_ZVA requires that we supply
* the original pointer for an invalid page. But watchpoints require
* that we probe the actual space. So do both.
*/
(void) probe_write(env, vaddr_in, 1, mmu_idx, ra);
mem = probe_write(env, vaddr, blocklen, mmu_idx, ra);
if (unlikely(!mem)) {
/*
* The only remaining reason for mem == NULL is I/O.
* Just do a series of byte writes as the architecture demands.
*/
for (int i = 0; i < blocklen; i++) {
cpu_stb_mmuidx_ra(env, vaddr + i, 0, mmu_idx, ra);
}
return;
}
}
#endif
memset(mem, 0, blocklen);
}
void HELPER(unaligned_access)(CPUARMState *env, uint64_t addr,
uint32_t access_type, uint32_t mmu_idx)
{
arm_cpu_do_unaligned_access(env_cpu(env), addr, access_type,
mmu_idx, GETPC());
}
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