qemu/target/arm/translate.h
Peter Maydell e33cf0f8d8 target/arm: Implement M-profile lazy FP state preservation
The M-profile architecture floating point system supports
lazy FP state preservation, where FP registers are not
pushed to the stack when an exception occurs but are instead
only saved if and when the first FP instruction in the exception
handler is executed. Implement this in QEMU, corresponding
to the check of LSPACT in the pseudocode ExecuteFPCheck().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190416125744.27770-24-peter.maydell@linaro.org
2019-04-29 17:36:02 +01:00

264 lines
8.6 KiB
C

#ifndef TARGET_ARM_TRANSLATE_H
#define TARGET_ARM_TRANSLATE_H
#include "exec/translator.h"
/* internal defines */
typedef struct DisasContext {
DisasContextBase base;
const ARMISARegisters *isar;
target_ulong pc;
target_ulong page_start;
uint32_t insn;
/* Nonzero if this instruction has been conditionally skipped. */
int condjmp;
/* The label that will be jumped to when the instruction is skipped. */
TCGLabel *condlabel;
/* Thumb-2 conditional execution bits. */
int condexec_mask;
int condexec_cond;
int thumb;
int sctlr_b;
TCGMemOp be_data;
#if !defined(CONFIG_USER_ONLY)
int user;
#endif
ARMMMUIdx mmu_idx; /* MMU index to use for normal loads/stores */
uint8_t tbii; /* TBI1|TBI0 for insns */
uint8_t tbid; /* TBI1|TBI0 for data */
bool ns; /* Use non-secure CPREG bank on access */
int fp_excp_el; /* FP exception EL or 0 if enabled */
int sve_excp_el; /* SVE exception EL or 0 if enabled */
int sve_len; /* SVE vector length in bytes */
/* Flag indicating that exceptions from secure mode are routed to EL3. */
bool secure_routed_to_el3;
bool vfp_enabled; /* FP enabled via FPSCR.EN */
int vec_len;
int vec_stride;
bool v7m_handler_mode;
bool v8m_secure; /* true if v8M and we're in Secure mode */
bool v8m_stackcheck; /* true if we need to perform v8M stack limit checks */
bool v8m_fpccr_s_wrong; /* true if v8M FPCCR.S != v8m_secure */
bool v7m_new_fp_ctxt_needed; /* ASPEN set but no active FP context */
bool v7m_lspact; /* FPCCR.LSPACT set */
/* Immediate value in AArch32 SVC insn; must be set if is_jmp == DISAS_SWI
* so that top level loop can generate correct syndrome information.
*/
uint32_t svc_imm;
int aarch64;
int current_el;
GHashTable *cp_regs;
uint64_t features; /* CPU features bits */
/* Because unallocated encodings generate different exception syndrome
* information from traps due to FP being disabled, we can't do a single
* "is fp access disabled" check at a high level in the decode tree.
* To help in catching bugs where the access check was forgotten in some
* code path, we set this flag when the access check is done, and assert
* that it is set at the point where we actually touch the FP regs.
*/
bool fp_access_checked;
/* ARMv8 single-step state (this is distinct from the QEMU gdbstub
* single-step support).
*/
bool ss_active;
bool pstate_ss;
/* True if the insn just emitted was a load-exclusive instruction
* (necessary for syndrome information for single step exceptions),
* ie A64 LDX*, LDAX*, A32/T32 LDREX*, LDAEX*.
*/
bool is_ldex;
/* True if a single-step exception will be taken to the current EL */
bool ss_same_el;
/* True if v8.3-PAuth is active. */
bool pauth_active;
/* True with v8.5-BTI and SCTLR_ELx.BT* set. */
bool bt;
/*
* >= 0, a copy of PSTATE.BTYPE, which will be 0 without v8.5-BTI.
* < 0, set by the current instruction.
*/
int8_t btype;
/* True if this page is guarded. */
bool guarded_page;
/* Bottom two bits of XScale c15_cpar coprocessor access control reg */
int c15_cpar;
/* TCG op of the current insn_start. */
TCGOp *insn_start;
#define TMP_A64_MAX 16
int tmp_a64_count;
TCGv_i64 tmp_a64[TMP_A64_MAX];
} DisasContext;
typedef struct DisasCompare {
TCGCond cond;
TCGv_i32 value;
bool value_global;
} DisasCompare;
/* Share the TCG temporaries common between 32 and 64 bit modes. */
extern TCGv_i32 cpu_NF, cpu_ZF, cpu_CF, cpu_VF;
extern TCGv_i64 cpu_exclusive_addr;
extern TCGv_i64 cpu_exclusive_val;
static inline int arm_dc_feature(DisasContext *dc, int feature)
{
return (dc->features & (1ULL << feature)) != 0;
}
static inline int get_mem_index(DisasContext *s)
{
return arm_to_core_mmu_idx(s->mmu_idx);
}
/* Function used to determine the target exception EL when otherwise not known
* or default.
*/
static inline int default_exception_el(DisasContext *s)
{
/* If we are coming from secure EL0 in a system with a 32-bit EL3, then
* there is no secure EL1, so we route exceptions to EL3. Otherwise,
* exceptions can only be routed to ELs above 1, so we target the higher of
* 1 or the current EL.
*/
return (s->mmu_idx == ARMMMUIdx_S1SE0 && s->secure_routed_to_el3)
? 3 : MAX(1, s->current_el);
}
static inline void disas_set_insn_syndrome(DisasContext *s, uint32_t syn)
{
/* We don't need to save all of the syndrome so we mask and shift
* out unneeded bits to help the sleb128 encoder do a better job.
*/
syn &= ARM_INSN_START_WORD2_MASK;
syn >>= ARM_INSN_START_WORD2_SHIFT;
/* We check and clear insn_start_idx to catch multiple updates. */
assert(s->insn_start != NULL);
tcg_set_insn_start_param(s->insn_start, 2, syn);
s->insn_start = NULL;
}
/* is_jmp field values */
#define DISAS_JUMP DISAS_TARGET_0 /* only pc was modified dynamically */
#define DISAS_UPDATE DISAS_TARGET_1 /* cpu state was modified dynamically */
/* These instructions trap after executing, so the A32/T32 decoder must
* defer them until after the conditional execution state has been updated.
* WFI also needs special handling when single-stepping.
*/
#define DISAS_WFI DISAS_TARGET_2
#define DISAS_SWI DISAS_TARGET_3
/* WFE */
#define DISAS_WFE DISAS_TARGET_4
#define DISAS_HVC DISAS_TARGET_5
#define DISAS_SMC DISAS_TARGET_6
#define DISAS_YIELD DISAS_TARGET_7
/* M profile branch which might be an exception return (and so needs
* custom end-of-TB code)
*/
#define DISAS_BX_EXCRET DISAS_TARGET_8
/* For instructions which want an immediate exit to the main loop,
* as opposed to attempting to use lookup_and_goto_ptr. Unlike
* DISAS_UPDATE this doesn't write the PC on exiting the translation
* loop so you need to ensure something (gen_a64_set_pc_im or runtime
* helper) has done so before we reach return from cpu_tb_exec.
*/
#define DISAS_EXIT DISAS_TARGET_9
#ifdef TARGET_AARCH64
void a64_translate_init(void);
void gen_a64_set_pc_im(uint64_t val);
void aarch64_cpu_dump_state(CPUState *cs, FILE *f, int flags);
extern const TranslatorOps aarch64_translator_ops;
#else
static inline void a64_translate_init(void)
{
}
static inline void gen_a64_set_pc_im(uint64_t val)
{
}
static inline void aarch64_cpu_dump_state(CPUState *cs, FILE *f, int flags)
{
}
#endif
void arm_test_cc(DisasCompare *cmp, int cc);
void arm_free_cc(DisasCompare *cmp);
void arm_jump_cc(DisasCompare *cmp, TCGLabel *label);
void arm_gen_test_cc(int cc, TCGLabel *label);
/* Return state of Alternate Half-precision flag, caller frees result */
static inline TCGv_i32 get_ahp_flag(void)
{
TCGv_i32 ret = tcg_temp_new_i32();
tcg_gen_ld_i32(ret, cpu_env,
offsetof(CPUARMState, vfp.xregs[ARM_VFP_FPSCR]));
tcg_gen_extract_i32(ret, ret, 26, 1);
return ret;
}
/* Set bits within PSTATE. */
static inline void set_pstate_bits(uint32_t bits)
{
TCGv_i32 p = tcg_temp_new_i32();
tcg_debug_assert(!(bits & CACHED_PSTATE_BITS));
tcg_gen_ld_i32(p, cpu_env, offsetof(CPUARMState, pstate));
tcg_gen_ori_i32(p, p, bits);
tcg_gen_st_i32(p, cpu_env, offsetof(CPUARMState, pstate));
tcg_temp_free_i32(p);
}
/* Clear bits within PSTATE. */
static inline void clear_pstate_bits(uint32_t bits)
{
TCGv_i32 p = tcg_temp_new_i32();
tcg_debug_assert(!(bits & CACHED_PSTATE_BITS));
tcg_gen_ld_i32(p, cpu_env, offsetof(CPUARMState, pstate));
tcg_gen_andi_i32(p, p, ~bits);
tcg_gen_st_i32(p, cpu_env, offsetof(CPUARMState, pstate));
tcg_temp_free_i32(p);
}
/* If the singlestep state is Active-not-pending, advance to Active-pending. */
static inline void gen_ss_advance(DisasContext *s)
{
if (s->ss_active) {
s->pstate_ss = 0;
clear_pstate_bits(PSTATE_SS);
}
}
/* Vector operations shared between ARM and AArch64. */
extern const GVecGen3 bsl_op;
extern const GVecGen3 bit_op;
extern const GVecGen3 bif_op;
extern const GVecGen3 mla_op[4];
extern const GVecGen3 mls_op[4];
extern const GVecGen3 cmtst_op[4];
extern const GVecGen2i ssra_op[4];
extern const GVecGen2i usra_op[4];
extern const GVecGen2i sri_op[4];
extern const GVecGen2i sli_op[4];
extern const GVecGen4 uqadd_op[4];
extern const GVecGen4 sqadd_op[4];
extern const GVecGen4 uqsub_op[4];
extern const GVecGen4 sqsub_op[4];
void gen_cmtst_i64(TCGv_i64 d, TCGv_i64 a, TCGv_i64 b);
/*
* Forward to the isar_feature_* tests given a DisasContext pointer.
*/
#define dc_isar_feature(name, ctx) \
({ DisasContext *ctx_ = (ctx); isar_feature_##name(ctx_->isar); })
#endif /* TARGET_ARM_TRANSLATE_H */