From 9dbbc748d671c70599101836cd1c2719d92f3017 Mon Sep 17 00:00:00 2001 From: Greg Bellows Date: Fri, 29 May 2015 11:28:53 +0100 Subject: [PATCH] target-arm: Extend FP checks to use an EL Extend the ARM disassemble context to take a target exception EL instead of a boolean enable. This change reverses the polarity of the check making a value of 0 indicate floating point enabled (no exception). Signed-off-by: Greg Bellows [PMM: Use a common TB flag field for AArch32 and AArch64; CPTR_EL2 exists in v7; CPTR_EL2 should trap for EL2 accesses; CPTR_EL2 should not trap for secure accesses; CPTR_EL3 should trap for EL3 accesses; CPACR traps for secure accesses should trap to EL3 if EL3 is AArch32] Signed-off-by: Peter Maydell Reviewed-by: Edgar E. Iglesias --- target-arm/cpu.h | 92 +++++++++++++++++++++++++++++++++++----------- target-arm/translate-a64.c | 8 ++-- target-arm/translate.c | 17 ++++----- target-arm/translate.h | 2 +- 4 files changed, 82 insertions(+), 37 deletions(-) diff --git a/target-arm/cpu.h b/target-arm/cpu.h index 8aeb8aae49..bf37c49739 100644 --- a/target-arm/cpu.h +++ b/target-arm/cpu.h @@ -1741,6 +1741,9 @@ static inline bool arm_singlestep_active(CPUARMState *env) #define ARM_TBFLAG_SS_ACTIVE_MASK (1 << ARM_TBFLAG_SS_ACTIVE_SHIFT) #define ARM_TBFLAG_PSTATE_SS_SHIFT 26 #define ARM_TBFLAG_PSTATE_SS_MASK (1 << ARM_TBFLAG_PSTATE_SS_SHIFT) +/* Target EL if we take a floating-point-disabled exception */ +#define ARM_TBFLAG_FPEXC_EL_SHIFT 24 +#define ARM_TBFLAG_FPEXC_EL_MASK (0x3 << ARM_TBFLAG_FPEXC_EL_SHIFT) /* Bit usage when in AArch32 state: */ #define ARM_TBFLAG_THUMB_SHIFT 0 @@ -1755,8 +1758,6 @@ static inline bool arm_singlestep_active(CPUARMState *env) #define ARM_TBFLAG_CONDEXEC_MASK (0xff << ARM_TBFLAG_CONDEXEC_SHIFT) #define ARM_TBFLAG_BSWAP_CODE_SHIFT 16 #define ARM_TBFLAG_BSWAP_CODE_MASK (1 << ARM_TBFLAG_BSWAP_CODE_SHIFT) -#define ARM_TBFLAG_CPACR_FPEN_SHIFT 17 -#define ARM_TBFLAG_CPACR_FPEN_MASK (1 << ARM_TBFLAG_CPACR_FPEN_SHIFT) /* We store the bottom two bits of the CPAR as TB flags and handle * checks on the other bits at runtime */ @@ -1769,9 +1770,7 @@ static inline bool arm_singlestep_active(CPUARMState *env) #define ARM_TBFLAG_NS_SHIFT 22 #define ARM_TBFLAG_NS_MASK (1 << ARM_TBFLAG_NS_SHIFT) -/* Bit usage when in AArch64 state */ -#define ARM_TBFLAG_AA64_FPEN_SHIFT 2 -#define ARM_TBFLAG_AA64_FPEN_MASK (1 << ARM_TBFLAG_AA64_FPEN_SHIFT) +/* Bit usage when in AArch64 state: currently we have no A64 specific bits */ /* some convenience accessor macros */ #define ARM_TBFLAG_AARCH64_STATE(F) \ @@ -1782,6 +1781,8 @@ static inline bool arm_singlestep_active(CPUARMState *env) (((F) & ARM_TBFLAG_SS_ACTIVE_MASK) >> ARM_TBFLAG_SS_ACTIVE_SHIFT) #define ARM_TBFLAG_PSTATE_SS(F) \ (((F) & ARM_TBFLAG_PSTATE_SS_MASK) >> ARM_TBFLAG_PSTATE_SS_SHIFT) +#define ARM_TBFLAG_FPEXC_EL(F) \ + (((F) & ARM_TBFLAG_FPEXC_EL_MASK) >> ARM_TBFLAG_FPEXC_EL_SHIFT) #define ARM_TBFLAG_THUMB(F) \ (((F) & ARM_TBFLAG_THUMB_MASK) >> ARM_TBFLAG_THUMB_SHIFT) #define ARM_TBFLAG_VECLEN(F) \ @@ -1794,33 +1795,82 @@ static inline bool arm_singlestep_active(CPUARMState *env) (((F) & ARM_TBFLAG_CONDEXEC_MASK) >> ARM_TBFLAG_CONDEXEC_SHIFT) #define ARM_TBFLAG_BSWAP_CODE(F) \ (((F) & ARM_TBFLAG_BSWAP_CODE_MASK) >> ARM_TBFLAG_BSWAP_CODE_SHIFT) -#define ARM_TBFLAG_CPACR_FPEN(F) \ - (((F) & ARM_TBFLAG_CPACR_FPEN_MASK) >> ARM_TBFLAG_CPACR_FPEN_SHIFT) #define ARM_TBFLAG_XSCALE_CPAR(F) \ (((F) & ARM_TBFLAG_XSCALE_CPAR_MASK) >> ARM_TBFLAG_XSCALE_CPAR_SHIFT) -#define ARM_TBFLAG_AA64_FPEN(F) \ - (((F) & ARM_TBFLAG_AA64_FPEN_MASK) >> ARM_TBFLAG_AA64_FPEN_SHIFT) #define ARM_TBFLAG_NS(F) \ (((F) & ARM_TBFLAG_NS_MASK) >> ARM_TBFLAG_NS_SHIFT) -static inline void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, - target_ulong *cs_base, int *flags) +/* Return the exception level to which FP-disabled exceptions should + * be taken, or 0 if FP is enabled. + */ +static inline int fp_exception_el(CPUARMState *env) { int fpen; + int cur_el = arm_current_el(env); - if (arm_feature(env, ARM_FEATURE_V6)) { - fpen = extract32(env->cp15.cpacr_el1, 20, 2); - } else { - /* CPACR doesn't exist before v6, so VFP is always accessible */ - fpen = 3; + /* CPACR and the CPTR registers don't exist before v6, so FP is + * always accessible + */ + if (!arm_feature(env, ARM_FEATURE_V6)) { + return 0; + } + + /* The CPACR controls traps to EL1, or PL1 if we're 32 bit: + * 0, 2 : trap EL0 and EL1/PL1 accesses + * 1 : trap only EL0 accesses + * 3 : trap no accesses + */ + fpen = extract32(env->cp15.cpacr_el1, 20, 2); + switch (fpen) { + case 0: + case 2: + if (cur_el == 0 || cur_el == 1) { + /* Trap to PL1, which might be EL1 or EL3 */ + if (arm_is_secure(env) && !arm_el_is_aa64(env, 3)) { + return 3; + } + return 1; + } + if (cur_el == 3 && !is_a64(env)) { + /* Secure PL1 running at EL3 */ + return 3; + } + break; + case 1: + if (cur_el == 0) { + return 1; + } + break; + case 3: + break; + } + + /* For the CPTR registers we don't need to guard with an ARM_FEATURE + * check because zero bits in the registers mean "don't trap". + */ + + /* CPTR_EL2 : present in v7VE or v8 */ + if (cur_el <= 2 && extract32(env->cp15.cptr_el[2], 10, 1) + && !arm_is_secure_below_el3(env)) { + /* Trap FP ops at EL2, NS-EL1 or NS-EL0 to EL2 */ + return 2; + } + + /* CPTR_EL3 : present in v8 */ + if (extract32(env->cp15.cptr_el[3], 10, 1)) { + /* Trap all FP ops to EL3 */ + return 3; } + return 0; +} + +static inline void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, + target_ulong *cs_base, int *flags) +{ if (is_a64(env)) { *pc = env->pc; *flags = ARM_TBFLAG_AARCH64_STATE_MASK; - if (fpen == 3 || (fpen == 1 && arm_current_el(env) != 0)) { - *flags |= ARM_TBFLAG_AA64_FPEN_MASK; - } } else { *pc = env->regs[15]; *flags = (env->thumb << ARM_TBFLAG_THUMB_SHIFT) @@ -1835,9 +1885,6 @@ static inline void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, || arm_el_is_aa64(env, 1)) { *flags |= ARM_TBFLAG_VFPEN_MASK; } - if (fpen == 3 || (fpen == 1 && arm_current_el(env) != 0)) { - *flags |= ARM_TBFLAG_CPACR_FPEN_MASK; - } *flags |= (extract32(env->cp15.c15_cpar, 0, 2) << ARM_TBFLAG_XSCALE_CPAR_SHIFT); } @@ -1862,6 +1909,7 @@ static inline void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, } } } + *flags |= fp_exception_el(env) << ARM_TBFLAG_FPEXC_EL_SHIFT; *cs_base = 0; } diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c index b58778a6b9..8d08ccdf6a 100644 --- a/target-arm/translate-a64.c +++ b/target-arm/translate-a64.c @@ -412,7 +412,7 @@ static TCGv_i64 read_cpu_reg_sp(DisasContext *s, int reg, int sf) static inline void assert_fp_access_checked(DisasContext *s) { #ifdef CONFIG_DEBUG_TCG - if (unlikely(!s->fp_access_checked || !s->cpacr_fpen)) { + if (unlikely(!s->fp_access_checked || s->fp_excp_el)) { fprintf(stderr, "target-arm: FP access check missing for " "instruction 0x%08x\n", s->insn); abort(); @@ -972,12 +972,12 @@ static inline bool fp_access_check(DisasContext *s) assert(!s->fp_access_checked); s->fp_access_checked = true; - if (s->cpacr_fpen) { + if (!s->fp_excp_el) { return true; } gen_exception_insn(s, 4, EXCP_UDEF, syn_fp_access_trap(1, 0xe, false), - default_exception_el(s)); + s->fp_excp_el); return false; } @@ -10954,7 +10954,7 @@ void gen_intermediate_code_internal_a64(ARMCPU *cpu, #if !defined(CONFIG_USER_ONLY) dc->user = (dc->current_el == 0); #endif - dc->cpacr_fpen = ARM_TBFLAG_AA64_FPEN(tb->flags); + dc->fp_excp_el = ARM_TBFLAG_FPEXC_EL(tb->flags); dc->vec_len = 0; dc->vec_stride = 0; dc->cp_regs = cpu->cp_regs; diff --git a/target-arm/translate.c b/target-arm/translate.c index 2bd573354f..ed2c43d235 100644 --- a/target-arm/translate.c +++ b/target-arm/translate.c @@ -3044,10 +3044,9 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn) * for invalid encodings; we will generate incorrect syndrome information * for attempts to execute invalid vfp/neon encodings with FP disabled. */ - if (!s->cpacr_fpen) { + if (s->fp_excp_el) { gen_exception_insn(s, 4, EXCP_UDEF, - syn_fp_access_trap(1, 0xe, s->thumb), - default_exception_el(s)); + syn_fp_access_trap(1, 0xe, s->thumb), s->fp_excp_el); return 0; } @@ -4363,10 +4362,9 @@ static int disas_neon_ls_insn(DisasContext *s, uint32_t insn) * for invalid encodings; we will generate incorrect syndrome information * for attempts to execute invalid vfp/neon encodings with FP disabled. */ - if (!s->cpacr_fpen) { + if (s->fp_excp_el) { gen_exception_insn(s, 4, EXCP_UDEF, - syn_fp_access_trap(1, 0xe, s->thumb), - default_exception_el(s)); + syn_fp_access_trap(1, 0xe, s->thumb), s->fp_excp_el); return 0; } @@ -5102,10 +5100,9 @@ static int disas_neon_data_insn(DisasContext *s, uint32_t insn) * for invalid encodings; we will generate incorrect syndrome information * for attempts to execute invalid vfp/neon encodings with FP disabled. */ - if (!s->cpacr_fpen) { + if (s->fp_excp_el) { gen_exception_insn(s, 4, EXCP_UDEF, - syn_fp_access_trap(1, 0xe, s->thumb), - default_exception_el(s)); + syn_fp_access_trap(1, 0xe, s->thumb), s->fp_excp_el); return 0; } @@ -11082,7 +11079,7 @@ static inline void gen_intermediate_code_internal(ARMCPU *cpu, dc->user = (dc->current_el == 0); #endif dc->ns = ARM_TBFLAG_NS(tb->flags); - dc->cpacr_fpen = ARM_TBFLAG_CPACR_FPEN(tb->flags); + dc->fp_excp_el = ARM_TBFLAG_FPEXC_EL(tb->flags); dc->vfp_enabled = ARM_TBFLAG_VFPEN(tb->flags); dc->vec_len = ARM_TBFLAG_VECLEN(tb->flags); dc->vec_stride = ARM_TBFLAG_VECSTRIDE(tb->flags); diff --git a/target-arm/translate.h b/target-arm/translate.h index 2eadcb7f06..bcdcf11718 100644 --- a/target-arm/translate.h +++ b/target-arm/translate.h @@ -22,7 +22,7 @@ typedef struct DisasContext { #endif ARMMMUIdx mmu_idx; /* MMU index to use for normal loads/stores */ bool ns; /* Use non-secure CPREG bank on access */ - bool cpacr_fpen; /* FP enabled via CPACR.FPEN */ + int fp_excp_el; /* FP exception EL or 0 if enabled */ bool el3_is_aa64; /* Flag indicating whether EL3 is AArch64 or not */ bool vfp_enabled; /* FP enabled via FPSCR.EN */ int vec_len; -- 2.11.0