From 485eb324e352a53bdf99f90511bd546eebab68f5 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 7 Mar 2024 12:19:03 +0000 Subject: [PATCH] target/arm: Define CNTPCTSS_EL0 and CNTVCTSS_EL0 For FEAT_ECV, new registers CNTPCTSS_EL0 and CNTVCTSS_EL0 are defined, which are "self-synchronized" views of the physical and virtual counts as seen in the CNTPCT_EL0 and CNTVCT_EL0 registers (meaning that no barriers are needed around accesses to them to ensure that reads of them do not occur speculatively and out-of-order with other instructions). For QEMU, all our system registers are self-synchronized, so we can simply copy the existing implementation of CNTPCT_EL0 and CNTVCT_EL0 to the new register encodings. This means we now implement all the functionality required for ID_AA64MMFR0_EL1.ECV == 0b0001. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20240301183219.2424889-7-peter.maydell@linaro.org --- target/arm/helper.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/target/arm/helper.c b/target/arm/helper.c index 46e0c3c4fc..68b5d6a4cb 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -3389,6 +3389,34 @@ static const ARMCPRegInfo generic_timer_cp_reginfo[] = { }, }; +/* + * FEAT_ECV adds extra views of CNTVCT_EL0 and CNTPCT_EL0 which + * are "self-synchronizing". For QEMU all sysregs are self-synchronizing, + * so our implementations here are identical to the normal registers. + */ +static const ARMCPRegInfo gen_timer_ecv_cp_reginfo[] = { + { .name = "CNTVCTSS", .cp = 15, .crm = 14, .opc1 = 9, + .access = PL0_R, .type = ARM_CP_64BIT | ARM_CP_NO_RAW | ARM_CP_IO, + .accessfn = gt_vct_access, + .readfn = gt_virt_cnt_read, .resetfn = arm_cp_reset_ignore, + }, + { .name = "CNTVCTSS_EL0", .state = ARM_CP_STATE_AA64, + .opc0 = 3, .opc1 = 3, .crn = 14, .crm = 0, .opc2 = 6, + .access = PL0_R, .type = ARM_CP_NO_RAW | ARM_CP_IO, + .accessfn = gt_vct_access, .readfn = gt_virt_cnt_read, + }, + { .name = "CNTPCTSS", .cp = 15, .crm = 14, .opc1 = 8, + .access = PL0_R, .type = ARM_CP_64BIT | ARM_CP_NO_RAW | ARM_CP_IO, + .accessfn = gt_pct_access, + .readfn = gt_cnt_read, .resetfn = arm_cp_reset_ignore, + }, + { .name = "CNTPCTSS_EL0", .state = ARM_CP_STATE_AA64, + .opc0 = 3, .opc1 = 3, .crn = 14, .crm = 0, .opc2 = 5, + .access = PL0_R, .type = ARM_CP_NO_RAW | ARM_CP_IO, + .accessfn = gt_pct_access, .readfn = gt_cnt_read, + }, +}; + #else /* @@ -3422,6 +3450,18 @@ static const ARMCPRegInfo generic_timer_cp_reginfo[] = { }, }; +/* + * CNTVCTSS_EL0 has the same trap conditions as CNTVCT_EL0, so it also + * is exposed to userspace by Linux. + */ +static const ARMCPRegInfo gen_timer_ecv_cp_reginfo[] = { + { .name = "CNTVCTSS_EL0", .state = ARM_CP_STATE_AA64, + .opc0 = 3, .opc1 = 3, .crn = 14, .crm = 0, .opc2 = 6, + .access = PL0_R, .type = ARM_CP_NO_RAW | ARM_CP_IO, + .readfn = gt_virt_cnt_read, + }, +}; + #endif static void par_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value) @@ -9258,6 +9298,9 @@ void register_cp_regs_for_features(ARMCPU *cpu) if (arm_feature(env, ARM_FEATURE_GENERIC_TIMER)) { define_arm_cp_regs(cpu, generic_timer_cp_reginfo); } + if (cpu_isar_feature(aa64_ecv_traps, cpu)) { + define_arm_cp_regs(cpu, gen_timer_ecv_cp_reginfo); + } if (arm_feature(env, ARM_FEATURE_VAPA)) { ARMCPRegInfo vapa_cp_reginfo[] = { { .name = "PAR", .cp = 15, .crn = 7, .crm = 4, .opc1 = 0, .opc2 = 0, -- 2.39.5