From 4a9ee99db38ba513bf1e8f43665b79c60accd017 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 5 Feb 2019 16:52:39 +0000 Subject: target/arm: Add TBFLAG_A64_TBID, split out gen_top_byte_ignore Split out gen_top_byte_ignore in preparation of handling these data accesses; the new tbflags field is not yet honored. Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson Message-id: 20190204132126.3255-2-richard.henderson@linaro.org Signed-off-by: Peter Maydell --- target/arm/translate-a64.c | 70 +++++++++++++++++++++++----------------------- 1 file changed, 35 insertions(+), 35 deletions(-) (limited to 'target/arm/translate-a64.c') diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index 7375ebf7a9..d24a083a19 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -284,10 +284,10 @@ void gen_a64_set_pc_im(uint64_t val) tcg_gen_movi_i64(cpu_pc, val); } -/* Load the PC from a generic TCG variable. +/* + * Handle Top Byte Ignore (TBI) bits. * - * If address tagging is enabled via the TCR TBI bits, then loading - * an address into the PC will clear out any tag in it: + * If address tagging is enabled via the TCR TBI bits: * + for EL2 and EL3 there is only one TBI bit, and if it is set * then the address is zero-extended, clearing bits [63:56] * + for EL0 and EL1, TBI0 controls addresses with bit 55 == 0 @@ -295,45 +295,44 @@ void gen_a64_set_pc_im(uint64_t val) * If the appropriate TBI bit is set for the address then * the address is sign-extended from bit 55 into bits [63:56] * - * We can avoid doing this for relative-branches, because the - * PC + offset can never overflow into the tag bits (assuming - * that virtual addresses are less than 56 bits wide, as they - * are currently), but we must handle it for branch-to-register. + * Here We have concatenated TBI{1,0} into tbi. */ -static void gen_a64_set_pc(DisasContext *s, TCGv_i64 src) +static void gen_top_byte_ignore(DisasContext *s, TCGv_i64 dst, + TCGv_i64 src, int tbi) { - /* Note that TBII is TBI1:TBI0. */ - int tbi = s->tbii; - - if (s->current_el <= 1) { - if (tbi != 0) { - /* Sign-extend from bit 55. */ - tcg_gen_sextract_i64(cpu_pc, src, 0, 56); + if (tbi == 0) { + /* Load unmodified address */ + tcg_gen_mov_i64(dst, src); + } else if (s->current_el >= 2) { + /* FIXME: ARMv8.1-VHE S2 translation regime. */ + /* Force tag byte to all zero */ + tcg_gen_extract_i64(dst, src, 0, 56); + } else { + /* Sign-extend from bit 55. */ + tcg_gen_sextract_i64(dst, src, 0, 56); - if (tbi != 3) { - TCGv_i64 tcg_zero = tcg_const_i64(0); + if (tbi != 3) { + TCGv_i64 tcg_zero = tcg_const_i64(0); - /* - * The two TBI bits differ. - * If tbi0, then !tbi1: only use the extension if positive. - * if !tbi0, then tbi1: only use the extension if negative. - */ - tcg_gen_movcond_i64(tbi == 1 ? TCG_COND_GE : TCG_COND_LT, - cpu_pc, cpu_pc, tcg_zero, cpu_pc, src); - tcg_temp_free_i64(tcg_zero); - } - return; - } - } else { - if (tbi != 0) { - /* Force tag byte to all zero */ - tcg_gen_extract_i64(cpu_pc, src, 0, 56); - return; + /* + * The two TBI bits differ. + * If tbi0, then !tbi1: only use the extension if positive. + * if !tbi0, then tbi1: only use the extension if negative. + */ + tcg_gen_movcond_i64(tbi == 1 ? TCG_COND_GE : TCG_COND_LT, + dst, dst, tcg_zero, dst, src); + tcg_temp_free_i64(tcg_zero); } } +} - /* Load unmodified address */ - tcg_gen_mov_i64(cpu_pc, src); +static void gen_a64_set_pc(DisasContext *s, TCGv_i64 src) +{ + /* + * If address tagging is enabled for instructions via the TCR TBI bits, + * then loading an address into the PC will clear out any tag. + */ + gen_top_byte_ignore(s, cpu_pc, src, s->tbii); } typedef struct DisasCompare64 { @@ -14012,6 +14011,7 @@ static void aarch64_tr_init_disas_context(DisasContextBase *dcbase, core_mmu_idx = FIELD_EX32(tb_flags, TBFLAG_ANY, MMUIDX); dc->mmu_idx = core_to_arm_mmu_idx(env, core_mmu_idx); dc->tbii = FIELD_EX32(tb_flags, TBFLAG_A64, TBII); + dc->tbid = FIELD_EX32(tb_flags, TBFLAG_A64, TBID); dc->current_el = arm_mmu_idx_to_el(dc->mmu_idx); #if !defined(CONFIG_USER_ONLY) dc->user = (dc->current_el == 0); -- cgit v1.2.3