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Diffstat (limited to 'target/arm/tcg/helper-a64.c')
| -rw-r--r-- | target/arm/tcg/helper-a64.c | 954 |
1 files changed, 954 insertions, 0 deletions
diff --git a/target/arm/tcg/helper-a64.c b/target/arm/tcg/helper-a64.c new file mode 100644 index 0000000000..0972a4bdd0 --- /dev/null +++ b/target/arm/tcg/helper-a64.c @@ -0,0 +1,954 @@ +/* + * 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 "exec/gdbstub.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; + } + + 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); +} |