From 4b6a83fb0c34a6fcc7bb1058284e3c3674e54421 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Wed, 20 Jun 2012 11:57:06 +0000 Subject: target-arm: initial coprocessor register framework Initial infrastructure for data-driven registration of coprocessor register implementations. We still fall back to the old-style switch statements pending complete conversion of all existing registers. Signed-off-by: Peter Maydell --- target-arm/cpu.h | 201 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 201 insertions(+) (limited to 'target-arm/cpu.h') diff --git a/target-arm/cpu.h b/target-arm/cpu.h index d01285fd57..6c7d3e72e0 100644 --- a/target-arm/cpu.h +++ b/target-arm/cpu.h @@ -410,6 +410,207 @@ void cpu_arm_set_cp_io(CPUARMState *env, int cpnum, ARMReadCPFunc *cp_read, ARMWriteCPFunc *cp_write, void *opaque); +/* Interface for defining coprocessor registers. + * Registers are defined in tables of arm_cp_reginfo structs + * which are passed to define_arm_cp_regs(). + */ + +/* When looking up a coprocessor register we look for it + * via an integer which encodes all of: + * coprocessor number + * Crn, Crm, opc1, opc2 fields + * 32 or 64 bit register (ie is it accessed via MRC/MCR + * or via MRRC/MCRR?) + * We allow 4 bits for opc1 because MRRC/MCRR have a 4 bit field. + * (In this case crn and opc2 should be zero.) + */ +#define ENCODE_CP_REG(cp, is64, crn, crm, opc1, opc2) \ + (((cp) << 16) | ((is64) << 15) | ((crn) << 11) | \ + ((crm) << 7) | ((opc1) << 3) | (opc2)) + +#define DECODE_CPREG_CRN(enc) (((enc) >> 7) & 0xf) + +/* ARMCPRegInfo type field bits. If the SPECIAL bit is set this is a + * special-behaviour cp reg and bits [15..8] indicate what behaviour + * it has. Otherwise it is a simple cp reg, where CONST indicates that + * TCG can assume the value to be constant (ie load at translate time) + * and 64BIT indicates a 64 bit wide coprocessor register. SUPPRESS_TB_END + * indicates that the TB should not be ended after a write to this register + * (the default is that the TB ends after cp writes). OVERRIDE permits + * a register definition to override a previous definition for the + * same (cp, is64, crn, crm, opc1, opc2) tuple: either the new or the + * old must have the OVERRIDE bit set. + */ +#define ARM_CP_SPECIAL 1 +#define ARM_CP_CONST 2 +#define ARM_CP_64BIT 4 +#define ARM_CP_SUPPRESS_TB_END 8 +#define ARM_CP_OVERRIDE 16 +#define ARM_CP_NOP (ARM_CP_SPECIAL | (1 << 8)) +#define ARM_CP_WFI (ARM_CP_SPECIAL | (2 << 8)) +#define ARM_LAST_SPECIAL ARM_CP_WFI +/* Used only as a terminator for ARMCPRegInfo lists */ +#define ARM_CP_SENTINEL 0xffff +/* Mask of only the flag bits in a type field */ +#define ARM_CP_FLAG_MASK 0x1f + +/* Return true if cptype is a valid type field. This is used to try to + * catch errors where the sentinel has been accidentally left off the end + * of a list of registers. + */ +static inline bool cptype_valid(int cptype) +{ + return ((cptype & ~ARM_CP_FLAG_MASK) == 0) + || ((cptype & ARM_CP_SPECIAL) && + (cptype <= ARM_LAST_SPECIAL)); +} + +/* Access rights: + * We define bits for Read and Write access for what rev C of the v7-AR ARM ARM + * defines as PL0 (user), PL1 (fiq/irq/svc/abt/und/sys, ie privileged), and + * PL2 (hyp). The other level which has Read and Write bits is Secure PL1 + * (ie any of the privileged modes in Secure state, or Monitor mode). + * If a register is accessible in one privilege level it's always accessible + * in higher privilege levels too. Since "Secure PL1" also follows this rule + * (ie anything visible in PL2 is visible in S-PL1, some things are only + * visible in S-PL1) but "Secure PL1" is a bit of a mouthful, we bend the + * terminology a little and call this PL3. + * + * If access permissions for a register are more complex than can be + * described with these bits, then use a laxer set of restrictions, and + * do the more restrictive/complex check inside a helper function. + */ +#define PL3_R 0x80 +#define PL3_W 0x40 +#define PL2_R (0x20 | PL3_R) +#define PL2_W (0x10 | PL3_W) +#define PL1_R (0x08 | PL2_R) +#define PL1_W (0x04 | PL2_W) +#define PL0_R (0x02 | PL1_R) +#define PL0_W (0x01 | PL1_W) + +#define PL3_RW (PL3_R | PL3_W) +#define PL2_RW (PL2_R | PL2_W) +#define PL1_RW (PL1_R | PL1_W) +#define PL0_RW (PL0_R | PL0_W) + +static inline int arm_current_pl(CPUARMState *env) +{ + if ((env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_USR) { + return 0; + } + /* We don't currently implement the Virtualization or TrustZone + * extensions, so PL2 and PL3 don't exist for us. + */ + return 1; +} + +typedef struct ARMCPRegInfo ARMCPRegInfo; + +/* Access functions for coprocessor registers. These should return + * 0 on success, or one of the EXCP_* constants if access should cause + * an exception (in which case *value is not written). + */ +typedef int CPReadFn(CPUARMState *env, const ARMCPRegInfo *opaque, + uint64_t *value); +typedef int CPWriteFn(CPUARMState *env, const ARMCPRegInfo *opaque, + uint64_t value); +/* Hook function for register reset */ +typedef void CPResetFn(CPUARMState *env, const ARMCPRegInfo *opaque); + +#define CP_ANY 0xff + +/* Definition of an ARM coprocessor register */ +struct ARMCPRegInfo { + /* Name of register (useful mainly for debugging, need not be unique) */ + const char *name; + /* Location of register: coprocessor number and (crn,crm,opc1,opc2) + * tuple. Any of crm, opc1 and opc2 may be CP_ANY to indicate a + * 'wildcard' field -- any value of that field in the MRC/MCR insn + * will be decoded to this register. The register read and write + * callbacks will be passed an ARMCPRegInfo with the crn/crm/opc1/opc2 + * used by the program, so it is possible to register a wildcard and + * then behave differently on read/write if necessary. + * For 64 bit registers, only crm and opc1 are relevant; crn and opc2 + * must both be zero. + */ + uint8_t cp; + uint8_t crn; + uint8_t crm; + uint8_t opc1; + uint8_t opc2; + /* Register type: ARM_CP_* bits/values */ + int type; + /* Access rights: PL*_[RW] */ + int access; + /* The opaque pointer passed to define_arm_cp_regs_with_opaque() when + * this register was defined: can be used to hand data through to the + * register read/write functions, since they are passed the ARMCPRegInfo*. + */ + void *opaque; + /* Value of this register, if it is ARM_CP_CONST. Otherwise, if + * fieldoffset is non-zero, the reset value of the register. + */ + uint64_t resetvalue; + /* Offset of the field in CPUARMState for this register. This is not + * needed if either: + * 1. type is ARM_CP_CONST or one of the ARM_CP_SPECIALs + * 2. both readfn and writefn are specified + */ + ptrdiff_t fieldoffset; /* offsetof(CPUARMState, field) */ + /* Function for handling reads of this register. If NULL, then reads + * will be done by loading from the offset into CPUARMState specified + * by fieldoffset. + */ + CPReadFn *readfn; + /* Function for handling writes of this register. If NULL, then writes + * will be done by writing to the offset into CPUARMState specified + * by fieldoffset. + */ + CPWriteFn *writefn; + /* Function for resetting the register. If NULL, then reset will be done + * by writing resetvalue to the field specified in fieldoffset. If + * fieldoffset is 0 then no reset will be done. + */ + CPResetFn *resetfn; +}; + +/* Macros which are lvalues for the field in CPUARMState for the + * ARMCPRegInfo *ri. + */ +#define CPREG_FIELD32(env, ri) \ + (*(uint32_t *)((char *)(env) + (ri)->fieldoffset)) +#define CPREG_FIELD64(env, ri) \ + (*(uint64_t *)((char *)(env) + (ri)->fieldoffset)) + +#define REGINFO_SENTINEL { .type = ARM_CP_SENTINEL } + +void define_arm_cp_regs_with_opaque(ARMCPU *cpu, + const ARMCPRegInfo *regs, void *opaque); +void define_one_arm_cp_reg_with_opaque(ARMCPU *cpu, + const ARMCPRegInfo *regs, void *opaque); +static inline void define_arm_cp_regs(ARMCPU *cpu, const ARMCPRegInfo *regs) +{ + define_arm_cp_regs_with_opaque(cpu, regs, 0); +} +static inline void define_one_arm_cp_reg(ARMCPU *cpu, const ARMCPRegInfo *regs) +{ + define_one_arm_cp_reg_with_opaque(cpu, regs, 0); +} +const ARMCPRegInfo *get_arm_cp_reginfo(ARMCPU *cpu, uint32_t encoded_cp); + +/* CPWriteFn that can be used to implement writes-ignored behaviour */ +int arm_cp_write_ignore(CPUARMState *env, const ARMCPRegInfo *ri, + uint64_t value); +/* CPReadFn that can be used for read-as-zero behaviour */ +int arm_cp_read_zero(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t *value); + +static inline bool cp_access_ok(CPUARMState *env, + const ARMCPRegInfo *ri, int isread) +{ + return (ri->access >> ((arm_current_pl(env) * 2) + isread)) & 1; +} + /* Does the core conform to the the "MicroController" profile. e.g. Cortex-M3. Note the M in older cores (eg. ARM7TDMI) stands for Multiply. These are conventional cores (ie. Application or Realtime profile). */ -- cgit v1.2.1