From 5d2555a1fe7370feeb1efbbf276a653040910017 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 19 Oct 2020 16:12:53 +0100 Subject: target/arm: Implement v8.1M NOCP handling From v8.1M, disabled-coprocessor handling changes slightly: * coprocessors 8, 9, 14 and 15 are also governed by the cp10 enable bit, like cp11 * an extra range of instruction patterns is considered to be inside the coprocessor space We previously marked these up with TODO comments; implement the correct behaviour. Unfortunately there is no ID register field which indicates this behaviour. We could in theory test an unrelated ID register which indicates guaranteed-to-be-in-v8.1M behaviour like ID_ISAR0.CmpBranch >= 3 (low-overhead-loops), but it seems better to simply define a new ARM_FEATURE_V8_1M feature flag and use it for this and other new-in-v8.1M behaviour that isn't identifiable from the ID registers. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20201019151301.2046-3-peter.maydell@linaro.org --- target/arm/cpu.h | 1 + target/arm/m-nocp.decode | 10 ++++++---- target/arm/translate-vfp.c.inc | 17 +++++++++++++++-- 3 files changed, 22 insertions(+), 6 deletions(-) (limited to 'target') diff --git a/target/arm/cpu.h b/target/arm/cpu.h index cfff1b5c8f..74392fa029 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -1985,6 +1985,7 @@ enum arm_features { ARM_FEATURE_VBAR, /* has cp15 VBAR */ ARM_FEATURE_M_SECURITY, /* M profile Security Extension */ ARM_FEATURE_M_MAIN, /* M profile Main Extension */ + ARM_FEATURE_V8_1M, /* M profile extras only in v8.1M and later */ }; static inline int arm_feature(CPUARMState *env, int feature) diff --git a/target/arm/m-nocp.decode b/target/arm/m-nocp.decode index 7182d7d121..28c8ac6b94 100644 --- a/target/arm/m-nocp.decode +++ b/target/arm/m-nocp.decode @@ -29,14 +29,16 @@ # 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. +&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 - NOCP 111- 1110 ---- ---- ---- cp:4 ---- ---- - NOCP 111- 110- ---- ---- ---- cp:4 ---- ---- - # TODO: From v8.1M onwards we will also want this range to NOCP - #NOCP_8_1 111- 1111 ---- ---- ---- ---- ---- ---- cp=10 + NOCP 111- 1110 ---- ---- ---- cp:4 ---- ---- &nocp + NOCP 111- 110- ---- ---- ---- cp:4 ---- ---- &nocp + # From v8.1M onwards this range will also NOCP: + NOCP_8_1 111- 1111 ---- ---- ---- ---- ---- ---- &nocp cp=10 } diff --git a/target/arm/translate-vfp.c.inc b/target/arm/translate-vfp.c.inc index 9b11b81f80..a7ed9bc81b 100644 --- a/target/arm/translate-vfp.c.inc +++ b/target/arm/translate-vfp.c.inc @@ -3459,7 +3459,7 @@ static bool trans_VLLDM_VLSTM(DisasContext *s, arg_VLLDM_VLSTM *a) return true; } -static bool trans_NOCP(DisasContext *s, arg_NOCP *a) +static bool trans_NOCP(DisasContext *s, arg_nocp *a) { /* * Handle M-profile early check for disabled coprocessor: @@ -3472,7 +3472,11 @@ static bool trans_NOCP(DisasContext *s, arg_NOCP *a) if (a->cp == 11) { a->cp = 10; } - /* TODO: in v8.1M cp 8, 9, 14, 15 also are governed by the cp10 enable */ + 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, @@ -3489,6 +3493,15 @@ static bool trans_NOCP(DisasContext *s, arg_NOCP *a) 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); +} + static bool trans_VINS(DisasContext *s, arg_VINS *a) { TCGv_i32 rd, rm; -- cgit v1.2.3