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Diffstat (limited to 'target/arm/translate-m-nocp.c')
| -rw-r--r-- | target/arm/translate-m-nocp.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/target/arm/translate-m-nocp.c b/target/arm/translate-m-nocp.c new file mode 100644 index 0000000000..d47eb8e153 --- /dev/null +++ b/target/arm/translate-m-nocp.c @@ -0,0 +1,221 @@ +/* + * ARM translation: M-profile NOCP special-case instructions + * + * Copyright (c) 2020 Linaro, Ltd. + * + * 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 "tcg/tcg-op.h" +#include "translate.h" +#include "translate-a32.h" + +#include "decode-m-nocp.c.inc" + +/* + * Decode VLLDM and VLSTM are nonstandard because: + * * if there is no FPU then these insns must NOP in + * Secure state and UNDEF in Nonsecure state + * * if there is an FPU then these insns do not have + * the usual behaviour that vfp_access_check() provides of + * being controlled by CPACR/NSACR enable bits or the + * lazy-stacking logic. + */ +static bool trans_VLLDM_VLSTM(DisasContext *s, arg_VLLDM_VLSTM *a) +{ + TCGv_i32 fptr; + + if (!arm_dc_feature(s, ARM_FEATURE_M) || + !arm_dc_feature(s, ARM_FEATURE_V8)) { + return false; + } + + if (a->op) { + /* + * T2 encoding ({D0-D31} reglist): v8.1M and up. We choose not + * to take the IMPDEF option to make memory accesses to the stack + * slots that correspond to the D16-D31 registers (discarding + * read data and writing UNKNOWN values), so for us the T2 + * encoding behaves identically to the T1 encoding. + */ + if (!arm_dc_feature(s, ARM_FEATURE_V8_1M)) { + return false; + } + } else { + /* + * T1 encoding ({D0-D15} reglist); undef if we have 32 Dregs. + * This is currently architecturally impossible, but we add the + * check to stay in line with the pseudocode. Note that we must + * emit code for the UNDEF so it takes precedence over the NOCP. + */ + if (dc_isar_feature(aa32_simd_r32, s)) { + unallocated_encoding(s); + return true; + } + } + + /* + * If not secure, UNDEF. We must emit code for this + * rather than returning false so that this takes + * precedence over the m-nocp.decode NOCP fallback. + */ + if (!s->v8m_secure) { + unallocated_encoding(s); + return true; + } + /* If no fpu, NOP. */ + if (!dc_isar_feature(aa32_vfp, s)) { + return true; + } + + fptr = load_reg(s, a->rn); + if (a->l) { + gen_helper_v7m_vlldm(cpu_env, fptr); + } else { + gen_helper_v7m_vlstm(cpu_env, fptr); + } + tcg_temp_free_i32(fptr); + + /* End the TB, because we have updated FP control bits */ + s->base.is_jmp = DISAS_UPDATE_EXIT; + return true; +} + +static bool trans_VSCCLRM(DisasContext *s, arg_VSCCLRM *a) +{ + int btmreg, topreg; + TCGv_i64 zero; + TCGv_i32 aspen, sfpa; + + if (!dc_isar_feature(aa32_m_sec_state, s)) { + /* Before v8.1M, fall through in decode to NOCP check */ + return false; + } + + /* Explicitly UNDEF because this takes precedence over NOCP */ + if (!arm_dc_feature(s, ARM_FEATURE_M_MAIN) || !s->v8m_secure) { + unallocated_encoding(s); + return true; + } + + if (!dc_isar_feature(aa32_vfp_simd, s)) { + /* NOP if we have neither FP nor MVE */ + return true; + } + + /* + * If FPCCR.ASPEN != 0 && CONTROL_S.SFPA == 0 then there is no + * active floating point context so we must NOP (without doing + * any lazy state preservation or the NOCP check). + */ + aspen = load_cpu_field(v7m.fpccr[M_REG_S]); + sfpa = load_cpu_field(v7m.control[M_REG_S]); + tcg_gen_andi_i32(aspen, aspen, R_V7M_FPCCR_ASPEN_MASK); + tcg_gen_xori_i32(aspen, aspen, R_V7M_FPCCR_ASPEN_MASK); + tcg_gen_andi_i32(sfpa, sfpa, R_V7M_CONTROL_SFPA_MASK); + tcg_gen_or_i32(sfpa, sfpa, aspen); + arm_gen_condlabel(s); + tcg_gen_brcondi_i32(TCG_COND_EQ, sfpa, 0, s->condlabel); + + if (s->fp_excp_el != 0) { + gen_exception_insn(s, s->pc_curr, EXCP_NOCP, + syn_uncategorized(), s->fp_excp_el); + return true; + } + + topreg = a->vd + a->imm - 1; + btmreg = a->vd; + + /* Convert to Sreg numbers if the insn specified in Dregs */ + if (a->size == 3) { + topreg = topreg * 2 + 1; + btmreg *= 2; + } + + if (topreg > 63 || (topreg > 31 && !(topreg & 1))) { + /* UNPREDICTABLE: we choose to undef */ + unallocated_encoding(s); + return true; + } + + /* Silently ignore requests to clear D16-D31 if they don't exist */ + if (topreg > 31 && !dc_isar_feature(aa32_simd_r32, s)) { + topreg = 31; + } + + if (!vfp_access_check(s)) { + return true; + } + + /* Zero the Sregs from btmreg to topreg inclusive. */ + zero = tcg_const_i64(0); + if (btmreg & 1) { + write_neon_element64(zero, btmreg >> 1, 1, MO_32); + btmreg++; + } + for (; btmreg + 1 <= topreg; btmreg += 2) { + write_neon_element64(zero, btmreg >> 1, 0, MO_64); + } + if (btmreg == topreg) { + write_neon_element64(zero, btmreg >> 1, 0, MO_32); + btmreg++; + } + assert(btmreg == topreg + 1); + /* TODO: when MVE is implemented, zero VPR here */ + return true; +} + +static bool trans_NOCP(DisasContext *s, arg_nocp *a) +{ + /* + * Handle M-profile early check for disabled coprocessor: + * all we need to do here is emit the NOCP exception if + * the coprocessor is disabled. Otherwise we return false + * and the real VFP/etc decode will handle the insn. + */ + assert(arm_dc_feature(s, ARM_FEATURE_M)); + + if (a->cp == 11) { + a->cp = 10; + } + if (arm_dc_feature(s, ARM_FEATURE_V8_1M) && + (a->cp == 8 || a->cp == 9 || a->cp == 14 || a->cp == 15)) { + /* in v8.1M cp 8, 9, 14, 15 also are governed by the cp10 enable */ + a->cp = 10; + } + + if (a->cp != 10) { + gen_exception_insn(s, s->pc_curr, EXCP_NOCP, + syn_uncategorized(), default_exception_el(s)); + return true; + } + + if (s->fp_excp_el != 0) { + gen_exception_insn(s, s->pc_curr, EXCP_NOCP, + syn_uncategorized(), s->fp_excp_el); + return true; + } + + return false; +} + +static bool trans_NOCP_8_1(DisasContext *s, arg_nocp *a) +{ + /* This range needs a coprocessor check for v8.1M and later only */ + if (!arm_dc_feature(s, ARM_FEATURE_V8_1M)) { + return false; + } + return trans_NOCP(s, a); +} |