From 83ff3d6add965c9752324de11eac5687121ea826 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 19 Nov 2020 21:55:53 +0000 Subject: [PATCH] target/arm: Implement VSCCLRM insn Implement the v8.1M VSCCLRM insn, which zeros floating point registers if there is an active floating point context. This requires support in write_neon_element32() for the MO_32 element size, so add it. Because we want to use arm_gen_condlabel(), we need to move the definition of that function up in translate.c so it is before the #include of translate-vfp.c.inc. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20201119215617.29887-5-peter.maydell@linaro.org --- target/arm/cpu.h | 9 ++++ target/arm/m-nocp.decode | 8 +++- target/arm/translate-vfp.c.inc | 84 ++++++++++++++++++++++++++++++++++ target/arm/translate.c | 21 +++++---- 4 files changed, 111 insertions(+), 11 deletions(-) diff --git a/target/arm/cpu.h b/target/arm/cpu.h index e5514c8286..11400a9d24 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -3555,6 +3555,15 @@ static inline bool isar_feature_aa32_mprofile(const ARMISARegisters *id) return FIELD_EX32(id->id_pfr1, ID_PFR1, MPROGMOD) != 0; } +static inline bool isar_feature_aa32_m_sec_state(const ARMISARegisters *id) +{ + /* + * Return true if M-profile state handling insns + * (VSCCLRM, CLRM, FPCTX access insns) are implemented + */ + return FIELD_EX32(id->id_pfr1, ID_PFR1, SECURITY) >= 3; +} + static inline bool isar_feature_aa32_fp16_arith(const ARMISARegisters *id) { /* Sadly this is encoded differently for A-profile and M-profile */ diff --git a/target/arm/m-nocp.decode b/target/arm/m-nocp.decode index 28c8ac6b94..ccd62e8739 100644 --- a/target/arm/m-nocp.decode +++ b/target/arm/m-nocp.decode @@ -29,13 +29,17 @@ # If the coprocessor is not present or disabled then we will generate # the NOCP exception; otherwise we let the insn through to the main decode. +%vd_dp 22:1 12:4 +%vd_sp 12:4 22:1 + &nocp cp { # Special cases which do not take an early NOCP: VLLDM and VLSTM VLLDM_VLSTM 1110 1100 001 l:1 rn:4 0000 1010 0000 0000 - # TODO: VSCCLRM (new in v8.1M) is similar: - #VSCCLRM 1110 1100 1-01 1111 ---- 1011 ---- ---0 + # VSCCLRM (new in v8.1M) is similar: + VSCCLRM 1110 1100 1.01 1111 .... 1011 imm:7 0 vd=%vd_dp size=3 + VSCCLRM 1110 1100 1.01 1111 .... 1010 imm:8 vd=%vd_sp size=2 NOCP 111- 1110 ---- ---- ---- cp:4 ---- ---- &nocp NOCP 111- 110- ---- ---- ---- cp:4 ---- ---- &nocp diff --git a/target/arm/translate-vfp.c.inc b/target/arm/translate-vfp.c.inc index 96948f5a2d..2a67ed0f6e 100644 --- a/target/arm/translate-vfp.c.inc +++ b/target/arm/translate-vfp.c.inc @@ -3406,6 +3406,90 @@ static bool trans_VLLDM_VLSTM(DisasContext *s, arg_VLLDM_VLSTM *a) 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) { /* diff --git a/target/arm/translate.c b/target/arm/translate.c index 6d04ca3a8a..9f2b6018a2 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -100,6 +100,15 @@ void arm_translate_init(void) a64_translate_init(); } +/* Generate a label used for skipping this instruction */ +static void arm_gen_condlabel(DisasContext *s) +{ + if (!s->condjmp) { + s->condlabel = gen_new_label(); + s->condjmp = 1; + } +} + /* Flags for the disas_set_da_iss info argument: * lower bits hold the Rt register number, higher bits are flags. */ @@ -1221,6 +1230,9 @@ static void write_neon_element64(TCGv_i64 src, int reg, int ele, MemOp memop) long off = neon_element_offset(reg, ele, memop); switch (memop) { + case MO_32: + tcg_gen_st32_i64(src, cpu_env, off); + break; case MO_64: tcg_gen_st_i64(src, cpu_env, off); break; @@ -5156,15 +5168,6 @@ static void gen_srs(DisasContext *s, s->base.is_jmp = DISAS_UPDATE_EXIT; } -/* Generate a label used for skipping this instruction */ -static void arm_gen_condlabel(DisasContext *s) -{ - if (!s->condjmp) { - s->condlabel = gen_new_label(); - s->condjmp = 1; - } -} - /* Skip this instruction if the ARM condition is false */ static void arm_skip_unless(DisasContext *s, uint32_t cond) {