From 88727fc3ec897b176f30a6d41111c4a0e581d6e8 Mon Sep 17 00:00:00 2001 From: Andre Przywara Date: Thu, 26 Jan 2023 16:47:52 +0000 Subject: [PATCH] refactor(cpufeat): enable FEAT_DIT for FEAT_STATE_CHECKED At the moment we only support FEAT_DIT to be either unconditionally compiled in, or to be not supported at all. Add support for runtime detection (ENABLE_DIT=2), by splitting is_armv8_4_dit_present() into an ID register reading function and a second function to report the support status. That function considers both build time settings and runtime information (if needed). We use ENABLE_DIT in two occassions in assembly code, where we just set the DIT bit in the DIT system register. Protect those two cases by reading the CPU ID register when ENABLE_DIT is set to 2. Change the FVP platform default to the now supported dynamic option (=2), so the right decision can be made by the code at runtime. Change-Id: I506d352f18e23c60db8cdf08edb449f60adbe098 Signed-off-by: Andre Przywara --- bl32/tsp/tsp_main.c | 2 +- common/feat_detect.c | 12 +---------- include/arch/aarch32/arch_features.h | 18 ++++++++++++++++ include/arch/aarch64/arch_features.h | 27 +++++++++++++----------- include/arch/aarch64/el3_common_macros.S | 8 ++++++- lib/el3_runtime/aarch64/context.S | 6 ++++++ plat/arm/board/fvp/platform.mk | 1 + 7 files changed, 49 insertions(+), 25 deletions(-) diff --git a/bl32/tsp/tsp_main.c b/bl32/tsp/tsp_main.c index df9903bb2..0878ea4d3 100644 --- a/bl32/tsp/tsp_main.c +++ b/bl32/tsp/tsp_main.c @@ -263,7 +263,7 @@ smc_args_t *tsp_smc_handler(uint64_t func, results[1] /= service_arg1 ? service_arg1 : 1; break; case TSP_CHECK_DIT: - if (!is_armv8_4_dit_present()) { + if (!is_feat_dit_supported()) { ERROR("DIT not supported\n"); results[0] = 0; results[1] = 0xffff; diff --git a/common/feat_detect.c b/common/feat_detect.c index 98b420a33..c8a070392 100644 --- a/common/feat_detect.c +++ b/common/feat_detect.c @@ -80,16 +80,6 @@ static void read_feat_pauth(void) #endif } -/************************************************************ - * Feature : FEAT_DIT (Data Independent Timing Instructions) - ***********************************************************/ -static void read_feat_dit(void) -{ -#if (ENABLE_FEAT_DIT == FEAT_STATE_ALWAYS) - feat_detect_panic(is_armv8_4_feat_dit_present(), "DIT"); -#endif -} - /************************************************ * Feature : FEAT_MTE (Memory Tagging Extension) ***********************************************/ @@ -178,7 +168,7 @@ void detect_arch_features(void) read_feat_pauth(); /* v8.4 features */ - read_feat_dit(); + check_feature(ENABLE_FEAT_DIT, read_feat_dit_id_field(), "DIT", 1, 1); check_feature(ENABLE_FEAT_AMU, read_feat_amu_id_field(), "AMUv1", 1, 2); check_feature(ENABLE_MPAM_FOR_LOWER_ELS, read_feat_mpam_version(), diff --git a/include/arch/aarch32/arch_features.h b/include/arch/aarch32/arch_features.h index 7c25b99ac..62a512b3e 100644 --- a/include/arch/aarch32/arch_features.h +++ b/include/arch/aarch32/arch_features.h @@ -92,6 +92,24 @@ static inline bool is_feat_sys_reg_trace_supported(void) return read_feat_coptrc_id_field() != 0U; } +static inline unsigned int read_feat_dit_id_field(void) +{ + return ISOLATE_FIELD(read_id_pfr0(), ID_PFR0_DIT); +} + +static inline bool is_feat_dit_supported(void) +{ + if (ENABLE_FEAT_DIT == FEAT_STATE_DISABLED) { + return false; + } + + if (ENABLE_FEAT_DIT == FEAT_STATE_ALWAYS) { + return true; + } + + return read_feat_dit_id_field() != 0U; +} + static inline bool is_feat_spe_supported(void) { /* FEAT_SPE is AArch64 only */ diff --git a/include/arch/aarch64/arch_features.h b/include/arch/aarch64/arch_features.h index 16f4fb996..40ab82fb0 100644 --- a/include/arch/aarch64/arch_features.h +++ b/include/arch/aarch64/arch_features.h @@ -89,12 +89,6 @@ static inline bool is_armv8_3_pauth_present(void) is_feat_pacqarma3_present()); } -static inline bool is_armv8_4_dit_present(void) -{ - return ((read_id_aa64pfr0_el1() >> ID_AA64PFR0_DIT_SHIFT) & - ID_AA64PFR0_DIT_MASK) == 1U; -} - static inline bool is_armv8_4_ttst_present(void) { return ((read_id_aa64mmfr2_el1() >> ID_AA64MMFR2_EL1_ST_SHIFT) & @@ -515,13 +509,22 @@ static inline bool is_armv8_2_feat_ras_present(void) ID_AA64PFR0_RAS_MASK) != ID_AA64PFR0_RAS_NOT_SUPPORTED); } -/************************************************************************** - * Function to identify the presence of FEAT_DIT (Data Independent Timing) - *************************************************************************/ -static inline bool is_armv8_4_feat_dit_present(void) +static unsigned int read_feat_dit_id_field(void) +{ + return ISOLATE_FIELD(read_id_aa64pfr0_el1(), ID_AA64PFR0_DIT); +} + +static inline bool is_feat_dit_supported(void) { - return (((read_id_aa64pfr0_el1() >> ID_AA64PFR0_DIT_SHIFT) & - ID_AA64PFR0_DIT_MASK) == ID_AA64PFR0_DIT_SUPPORTED); + if (ENABLE_FEAT_DIT == FEAT_STATE_DISABLED) { + return false; + } + + if (ENABLE_FEAT_DIT == FEAT_STATE_ALWAYS) { + return true; + } + + return read_feat_dit_id_field() != 0U; } static inline unsigned int read_feat_tracever_id_field(void) diff --git a/include/arch/aarch64/el3_common_macros.S b/include/arch/aarch64/el3_common_macros.S index 45a86c10e..2dee07d2a 100644 --- a/include/arch/aarch64/el3_common_macros.S +++ b/include/arch/aarch64/el3_common_macros.S @@ -243,14 +243,20 @@ * register value for DIT. */ #if ENABLE_FEAT_DIT -#if ENABLE_ASSERTIONS +#if ENABLE_ASSERTIONS || ENABLE_FEAT_DIT > 1 mrs x0, id_aa64pfr0_el1 ubfx x0, x0, #ID_AA64PFR0_DIT_SHIFT, #ID_AA64PFR0_DIT_LENGTH +#if ENABLE_FEAT_DIT > 1 + cbz x0, 1f +#else cmp x0, #ID_AA64PFR0_DIT_SUPPORTED ASM_ASSERT(eq) +#endif + #endif /* ENABLE_ASSERTIONS */ mov x0, #DIT_BIT msr DIT, x0 +1: #endif .endm diff --git a/lib/el3_runtime/aarch64/context.S b/lib/el3_runtime/aarch64/context.S index 013a505d4..769117163 100644 --- a/lib/el3_runtime/aarch64/context.S +++ b/lib/el3_runtime/aarch64/context.S @@ -553,8 +553,14 @@ endfunc fpregs_context_restore * always enable DIT in EL3 */ #if ENABLE_FEAT_DIT +#if ENABLE_FEAT_DIT == 2 + mrs x8, id_aa64pfr0_el1 + and x8, x8, #(ID_AA64PFR0_DIT_MASK << ID_AA64PFR0_DIT_SHIFT) + cbz x8, 1f +#endif mov x8, #DIT_BIT msr DIT, x8 +1: #endif /* ENABLE_FEAT_DIT */ .endm /* set_unset_pstate_bits */ diff --git a/plat/arm/board/fvp/platform.mk b/plat/arm/board/fvp/platform.mk index e81f1eb65..214064bf1 100644 --- a/plat/arm/board/fvp/platform.mk +++ b/plat/arm/board/fvp/platform.mk @@ -70,6 +70,7 @@ endif ENABLE_TRBE_FOR_NS := 2 ENABLE_SYS_REG_TRACE_FOR_NS := 2 ENABLE_FEAT_CSV2_2 := 2 +ENABLE_FEAT_DIT := 2 ENABLE_FEAT_PAN := 2 ENABLE_FEAT_VHE := 2 CTX_INCLUDE_NEVE_REGS := 2 -- 2.39.5