From e8cedaf779c0c2b13e0cc1ca580beaf5a6562a73 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 18 Jun 2021 15:10:18 +0100 Subject: [PATCH] target/arm: Split vfp_access_check() into A and M versions vfp_access_check and its helper routine full_vfp_access_check() has gradually grown and is now an awkward mix of A-profile only and M-profile only pieces. Refactor it into an A-profile only and an M-profile only version, taking advantage of the fact that now the only direct call to full_vfp_access_check() is in A-profile-only code. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20210618141019.10671-7-peter.maydell@linaro.org --- target/arm/translate-vfp.c | 77 ++++++++++++++++++++++++++++------------------ 1 file changed, 47 insertions(+), 30 deletions(-) diff --git a/target/arm/translate-vfp.c b/target/arm/translate-vfp.c index 85418dee2e..d89c7834fa 100644 --- a/target/arm/translate-vfp.c +++ b/target/arm/translate-vfp.c @@ -188,32 +188,19 @@ static void gen_update_fp_context(DisasContext *s) } /* - * Check that VFP access is enabled. If it is, do the necessary - * M-profile lazy-FP handling and then return true. - * If not, emit code to generate an appropriate exception and - * return false. + * Check that VFP access is enabled, A-profile specific version. + * + * If VFP is enabled, return true. If not, emit code to generate an + * appropriate exception and return false. * The ignore_vfp_enabled argument specifies that we should ignore - * whether VFP is enabled via FPEXC[EN]: this should be true for FMXR/FMRX + * whether VFP is enabled via FPEXC.EN: this should be true for FMXR/FMRX * accesses to FPSID, FPEXC, MVFR0, MVFR1, MVFR2, and false for all other insns. */ -static bool full_vfp_access_check(DisasContext *s, bool ignore_vfp_enabled) +static bool vfp_access_check_a(DisasContext *s, bool ignore_vfp_enabled) { if (s->fp_excp_el) { - if (arm_dc_feature(s, ARM_FEATURE_M)) { - /* - * M-profile mostly catches the "FPU disabled" case early, in - * disas_m_nocp(), but a few insns (eg LCTP, WLSTP, DLSTP) - * which do coprocessor-checks are outside the large ranges of - * the encoding space handled by the patterns in m-nocp.decode, - * and for them we may need to raise NOCP here. - */ - gen_exception_insn(s, s->pc_curr, EXCP_NOCP, - syn_uncategorized(), s->fp_excp_el); - } else { - gen_exception_insn(s, s->pc_curr, EXCP_UDEF, - syn_fp_access_trap(1, 0xe, false), - s->fp_excp_el); - } + gen_exception_insn(s, s->pc_curr, EXCP_UDEF, + syn_fp_access_trap(1, 0xe, false), s->fp_excp_el); return false; } @@ -222,16 +209,38 @@ static bool full_vfp_access_check(DisasContext *s, bool ignore_vfp_enabled) unallocated_encoding(s); return false; } + return true; +} - if (arm_dc_feature(s, ARM_FEATURE_M)) { - /* Handle M-profile lazy FP state mechanics */ +/* + * Check that VFP access is enabled, M-profile specific version. + * + * If VFP is enabled, do the necessary M-profile lazy-FP handling and then + * return true. If not, emit code to generate an appropriate exception and + * return false. + */ +static bool vfp_access_check_m(DisasContext *s) +{ + if (s->fp_excp_el) { + /* + * M-profile mostly catches the "FPU disabled" case early, in + * disas_m_nocp(), but a few insns (eg LCTP, WLSTP, DLSTP) + * which do coprocessor-checks are outside the large ranges of + * the encoding space handled by the patterns in m-nocp.decode, + * and for them we may need to raise NOCP here. + */ + gen_exception_insn(s, s->pc_curr, EXCP_NOCP, + syn_uncategorized(), s->fp_excp_el); + return false; + } - /* Trigger lazy-state preservation if necessary */ - gen_preserve_fp_state(s); + /* Handle M-profile lazy FP state mechanics */ - /* Update ownership of FP context and create new FP context if needed */ - gen_update_fp_context(s); - } + /* Trigger lazy-state preservation if necessary */ + gen_preserve_fp_state(s); + + /* Update ownership of FP context and create new FP context if needed */ + gen_update_fp_context(s); return true; } @@ -242,7 +251,11 @@ static bool full_vfp_access_check(DisasContext *s, bool ignore_vfp_enabled) */ bool vfp_access_check(DisasContext *s) { - return full_vfp_access_check(s, false); + if (arm_dc_feature(s, ARM_FEATURE_M)) { + return vfp_access_check_m(s); + } else { + return vfp_access_check_a(s, false); + } } static bool trans_VSEL(DisasContext *s, arg_VSEL *a) @@ -732,7 +745,11 @@ static bool trans_VMSR_VMRS(DisasContext *s, arg_VMSR_VMRS *a) return false; } - if (!full_vfp_access_check(s, ignore_vfp_enabled)) { + /* + * Call vfp_access_check_a() directly, because we need to tell + * it to ignore FPEXC.EN for some register accesses. + */ + if (!vfp_access_check_a(s, ignore_vfp_enabled)) { return true; } -- 2.11.0