Patchwork [02/33] target-arm: initial coprocessor register framework

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Submitter Peter Maydell
Date June 20, 2012, 12:26 p.m.
Message ID <1340195241-16620-3-git-send-email-peter.maydell@linaro.org>
Download mbox | patch
Permalink /patch/166101/
State New
Headers show

Comments

Peter Maydell - June 20, 2012, 12:26 p.m.
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 <peter.maydell@linaro.org>
---
 target-arm/cpu-qom.h   |    3 +
 target-arm/cpu.c       |   41 ++++++++++
 target-arm/cpu.h       |  201 ++++++++++++++++++++++++++++++++++++++++++++++++
 target-arm/helper.c    |  101 ++++++++++++++++++++++++
 target-arm/helper.h    |    5 +
 target-arm/op_helper.c |   42 ++++++++++-
 target-arm/translate.c |  156 +++++++++++++++++++++++++++++++++++++-
 7 files changed, 546 insertions(+), 3 deletions(-)

Patch

diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
index a61c68d..848ac2f 100644
--- a/target-arm/cpu-qom.h
+++ b/target-arm/cpu-qom.h
@@ -58,6 +58,9 @@  typedef struct ARMCPU {
 
     CPUARMState env;
 
+    /* Coprocessor information */
+    GHashTable *cp_regs;
+
     /* The instance init functions for implementation-specific subclasses
      * set these fields to specify the implementation-dependent values of
      * various constant registers and reset values of non-constant
diff --git a/target-arm/cpu.c b/target-arm/cpu.c
index 934894b..6456a3d 100644
--- a/target-arm/cpu.c
+++ b/target-arm/cpu.c
@@ -24,6 +24,37 @@ 
 #include "hw/loader.h"
 #endif
 
+static void cp_reg_reset(gpointer key, gpointer value, gpointer opaque)
+{
+    /* Reset a single ARMCPRegInfo register */
+    ARMCPRegInfo *ri = value;
+    ARMCPU *cpu = opaque;
+
+    if (ri->type & ARM_CP_SPECIAL) {
+        return;
+    }
+
+    if (ri->resetfn) {
+        ri->resetfn(&cpu->env, ri);
+        return;
+    }
+
+    /* A zero offset is never possible as it would be regs[0]
+     * so we use it to indicate that reset is being handled elsewhere.
+     * This is basically only used for fields in non-core coprocessors
+     * (like the pxa2xx ones).
+     */
+    if (!ri->fieldoffset) {
+        return;
+    }
+
+    if (ri->type & ARM_CP_64BIT) {
+        CPREG_FIELD64(&cpu->env, ri) = ri->resetvalue;
+    } else {
+        CPREG_FIELD32(&cpu->env, ri) = ri->resetvalue;
+    }
+}
+
 /* CPUClass::reset() */
 static void arm_cpu_reset(CPUState *s)
 {
@@ -39,6 +70,7 @@  static void arm_cpu_reset(CPUState *s)
     acc->parent_reset(s);
 
     memset(env, 0, offsetof(CPUARMState, breakpoints));
+    g_hash_table_foreach(cpu->cp_regs, cp_reg_reset, cpu);
     env->cp15.c15_config_base_address = cpu->reset_cbar;
     env->cp15.c0_cpuid = cpu->midr;
     env->vfp.xregs[ARM_VFP_FPSID] = cpu->reset_fpsid;
@@ -130,6 +162,14 @@  static void arm_cpu_initfn(Object *obj)
     ARMCPU *cpu = ARM_CPU(obj);
 
     cpu_exec_init(&cpu->env);
+    cpu->cp_regs = g_hash_table_new_full(g_int_hash, g_int_equal,
+                                         g_free, g_free);
+}
+
+static void arm_cpu_finalizefn(Object *obj)
+{
+    ARMCPU *cpu = ARM_CPU(obj);
+    g_hash_table_destroy(cpu->cp_regs);
 }
 
 void arm_cpu_realize(ARMCPU *cpu)
@@ -657,6 +697,7 @@  static const TypeInfo arm_cpu_type_info = {
     .parent = TYPE_CPU,
     .instance_size = sizeof(ARMCPU),
     .instance_init = arm_cpu_initfn,
+    .instance_finalize = arm_cpu_finalizefn,
     .abstract = true,
     .class_size = sizeof(ARMCPUClass),
     .class_init = arm_cpu_class_init,
diff --git a/target-arm/cpu.h b/target-arm/cpu.h
index d01285f..6c7d3e7 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).  */
diff --git a/target-arm/helper.c b/target-arm/helper.c
index bbb1d05..7032423 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -137,6 +137,107 @@  void arm_cpu_list(FILE *f, fprintf_function cpu_fprintf)
     g_slist_free(list);
 }
 
+void define_one_arm_cp_reg_with_opaque(ARMCPU *cpu,
+                                       const ARMCPRegInfo *r, void *opaque)
+{
+    /* Define implementations of coprocessor registers.
+     * We store these in a hashtable because typically
+     * there are less than 150 registers in a space which
+     * is 16*16*16*8*8 = 262144 in size.
+     * Wildcarding is supported for the crm, opc1 and opc2 fields.
+     * If a register is defined twice then the second definition is
+     * used, so this can be used to define some generic registers and
+     * then override them with implementation specific variations.
+     * At least one of the original and the second definition should
+     * include ARM_CP_OVERRIDE in its type bits -- this is just a guard
+     * against accidental use.
+     */
+    int crm, opc1, opc2;
+    int crmmin = (r->crm == CP_ANY) ? 0 : r->crm;
+    int crmmax = (r->crm == CP_ANY) ? 15 : r->crm;
+    int opc1min = (r->opc1 == CP_ANY) ? 0 : r->opc1;
+    int opc1max = (r->opc1 == CP_ANY) ? 7 : r->opc1;
+    int opc2min = (r->opc2 == CP_ANY) ? 0 : r->opc2;
+    int opc2max = (r->opc2 == CP_ANY) ? 7 : r->opc2;
+    /* 64 bit registers have only CRm and Opc1 fields */
+    assert(!((r->type & ARM_CP_64BIT) && (r->opc2 || r->crn)));
+    /* Check that the register definition has enough info to handle
+     * reads and writes if they are permitted.
+     */
+    if (!(r->type & (ARM_CP_SPECIAL|ARM_CP_CONST))) {
+        if (r->access & PL3_R) {
+            assert(r->fieldoffset || r->readfn);
+        }
+        if (r->access & PL3_W) {
+            assert(r->fieldoffset || r->writefn);
+        }
+    }
+    /* Bad type field probably means missing sentinel at end of reg list */
+    assert(cptype_valid(r->type));
+    for (crm = crmmin; crm <= crmmax; crm++) {
+        for (opc1 = opc1min; opc1 <= opc1max; opc1++) {
+            for (opc2 = opc2min; opc2 <= opc2max; opc2++) {
+                uint32_t *key = g_new(uint32_t, 1);
+                ARMCPRegInfo *r2 = g_memdup(r, sizeof(ARMCPRegInfo));
+                int is64 = (r->type & ARM_CP_64BIT) ? 1 : 0;
+                *key = ENCODE_CP_REG(r->cp, is64, r->crn, crm, opc1, opc2);
+                r2->opaque = opaque;
+                /* Make sure reginfo passed to helpers for wildcarded regs
+                 * has the correct crm/opc1/opc2 for this reg, not CP_ANY:
+                 */
+                r2->crm = crm;
+                r2->opc1 = opc1;
+                r2->opc2 = opc2;
+                /* Overriding of an existing definition must be explicitly
+                 * requested.
+                 */
+                if (!(r->type & ARM_CP_OVERRIDE)) {
+                    ARMCPRegInfo *oldreg;
+                    oldreg = g_hash_table_lookup(cpu->cp_regs, key);
+                    if (oldreg && !(oldreg->type & ARM_CP_OVERRIDE)) {
+                        fprintf(stderr, "Register redefined: cp=%d %d bit "
+                                "crn=%d crm=%d opc1=%d opc2=%d, "
+                                "was %s, now %s\n", r2->cp, 32 + 32 * is64,
+                                r2->crn, r2->crm, r2->opc1, r2->opc2,
+                                oldreg->name, r2->name);
+                        assert(0);
+                    }
+                }
+                g_hash_table_insert(cpu->cp_regs, key, r2);
+            }
+        }
+    }
+}
+
+void define_arm_cp_regs_with_opaque(ARMCPU *cpu,
+                                    const ARMCPRegInfo *regs, void *opaque)
+{
+    /* Define a whole list of registers */
+    const ARMCPRegInfo *r;
+    for (r = regs; r->type != ARM_CP_SENTINEL; r++) {
+        define_one_arm_cp_reg_with_opaque(cpu, r, opaque);
+    }
+}
+
+const ARMCPRegInfo *get_arm_cp_reginfo(ARMCPU *cpu, uint32_t encoded_cp)
+{
+    return g_hash_table_lookup(cpu->cp_regs, &encoded_cp);
+}
+
+int arm_cp_write_ignore(CPUARMState *env, const ARMCPRegInfo *ri,
+                        uint64_t value)
+{
+    /* Helper coprocessor write function for write-ignore registers */
+    return 0;
+}
+
+int arm_cp_read_zero(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t *value)
+{
+    /* Helper coprocessor write function for read-as-zero registers */
+    *value = 0;
+    return 0;
+}
+
 static int bad_mode_switch(CPUARMState *env, int mode)
 {
     /* Return true if it is not valid for us to switch to
diff --git a/target-arm/helper.h b/target-arm/helper.h
index 16dd5fc..b6cefed 100644
--- a/target-arm/helper.h
+++ b/target-arm/helper.h
@@ -65,6 +65,11 @@  DEF_HELPER_2(get_cp15, i32, env, i32)
 DEF_HELPER_3(set_cp, void, env, i32, i32)
 DEF_HELPER_2(get_cp, i32, env, i32)
 
+DEF_HELPER_3(set_cp_reg, void, env, ptr, i32)
+DEF_HELPER_2(get_cp_reg, i32, env, ptr)
+DEF_HELPER_3(set_cp_reg64, void, env, ptr, i64)
+DEF_HELPER_2(get_cp_reg64, i64, env, ptr)
+
 DEF_HELPER_2(get_r13_banked, i32, env, i32)
 DEF_HELPER_3(set_r13_banked, void, env, i32, i32)
 
diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
index b53369d..490111c 100644
--- a/target-arm/op_helper.c
+++ b/target-arm/op_helper.c
@@ -23,13 +23,11 @@ 
 #define SIGNBIT (uint32_t)0x80000000
 #define SIGNBIT64 ((uint64_t)1 << 63)
 
-#if !defined(CONFIG_USER_ONLY)
 static void raise_exception(int tt)
 {
     env->exception_index = tt;
     cpu_loop_exit(env);
 }
-#endif
 
 uint32_t HELPER(neon_tbl)(uint32_t ireg, uint32_t def,
                           uint32_t rn, uint32_t maxindex)
@@ -287,6 +285,46 @@  void HELPER(set_user_reg)(uint32_t regno, uint32_t val)
     }
 }
 
+void HELPER(set_cp_reg)(CPUARMState *env, void *rip, uint32_t value)
+{
+    const ARMCPRegInfo *ri = rip;
+    int excp = ri->writefn(env, ri, value);
+    if (excp) {
+        raise_exception(excp);
+    }
+}
+
+uint32_t HELPER(get_cp_reg)(CPUARMState *env, void *rip)
+{
+    const ARMCPRegInfo *ri = rip;
+    uint64_t value;
+    int excp = ri->readfn(env, ri, &value);
+    if (excp) {
+        raise_exception(excp);
+    }
+    return value;
+}
+
+void HELPER(set_cp_reg64)(CPUARMState *env, void *rip, uint64_t value)
+{
+    const ARMCPRegInfo *ri = rip;
+    int excp = ri->writefn(env, ri, value);
+    if (excp) {
+        raise_exception(excp);
+    }
+}
+
+uint64_t HELPER(get_cp_reg64)(CPUARMState *env, void *rip)
+{
+    const ARMCPRegInfo *ri = rip;
+    uint64_t value;
+    int excp = ri->readfn(env, ri, &value);
+    if (excp) {
+        raise_exception(excp);
+    }
+    return value;
+}
+
 /* ??? Flag setting arithmetic is awkward because we need to do comparisons.
    The only way to do that in TCG is a conditional branch, which clobbers
    all our temporaries.  For now implement these as helper functions.  */
diff --git a/target-arm/translate.c b/target-arm/translate.c
index 437d9db..d7edda7 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -6479,13 +6479,16 @@  static int disas_cp14_write(CPUARMState * env, DisasContext *s, uint32_t insn)
 
 static int disas_coproc_insn(CPUARMState * env, DisasContext *s, uint32_t insn)
 {
-    int cpnum;
+    int cpnum, is64, crn, crm, opc1, opc2, isread, rt, rt2;
+    const ARMCPRegInfo *ri;
+    ARMCPU *cpu = arm_env_get_cpu(env);
 
     cpnum = (insn >> 8) & 0xf;
     if (arm_feature(env, ARM_FEATURE_XSCALE)
 	    && ((env->cp15.c15_cpar ^ 0x3fff) & (1 << cpnum)))
 	return 1;
 
+    /* First check for coprocessor space used for actual instructions */
     switch (cpnum) {
       case 0:
       case 1:
@@ -6498,6 +6501,157 @@  static int disas_coproc_insn(CPUARMState * env, DisasContext *s, uint32_t insn)
     case 10:
     case 11:
 	return disas_vfp_insn (env, s, insn);
+    default:
+        break;
+    }
+
+    /* Otherwise treat as a generic register access */
+    is64 = (insn & (1 << 25)) == 0;
+    if (!is64 && ((insn & (1 << 4)) == 0)) {
+        /* cdp */
+        return 1;
+    }
+
+    crm = insn & 0xf;
+    if (is64) {
+        crn = 0;
+        opc1 = (insn >> 4) & 0xf;
+        opc2 = 0;
+        rt2 = (insn >> 16) & 0xf;
+    } else {
+        crn = (insn >> 16) & 0xf;
+        opc1 = (insn >> 21) & 7;
+        opc2 = (insn >> 5) & 7;
+        rt2 = 0;
+    }
+    isread = (insn >> 20) & 1;
+    rt = (insn >> 12) & 0xf;
+
+    ri = get_arm_cp_reginfo(cpu,
+                            ENCODE_CP_REG(cpnum, is64, crn, crm, opc1, opc2));
+    if (ri) {
+        /* Check access permissions */
+        if (!cp_access_ok(env, ri, isread)) {
+            return 1;
+        }
+
+        /* Handle special cases first */
+        switch (ri->type & ~(ARM_CP_FLAG_MASK & ~ARM_CP_SPECIAL)) {
+        case ARM_CP_NOP:
+            return 0;
+        case ARM_CP_WFI:
+            if (isread) {
+                return 1;
+            }
+            gen_set_pc_im(s->pc);
+            s->is_jmp = DISAS_WFI;
+            break;
+        default:
+            break;
+        }
+
+        if (isread) {
+            /* Read */
+            if (is64) {
+                TCGv_i64 tmp64;
+                TCGv_i32 tmp;
+                if (ri->type & ARM_CP_CONST) {
+                    tmp64 = tcg_const_i64(ri->resetvalue);
+                } else if (ri->readfn) {
+                    TCGv_ptr tmpptr;
+                    gen_set_pc_im(s->pc);
+                    tmp64 = tcg_temp_new_i64();
+                    tmpptr = tcg_const_ptr(ri);
+                    gen_helper_get_cp_reg64(tmp64, cpu_env, tmpptr);
+                    tcg_temp_free_ptr(tmpptr);
+                } else {
+                    tmp64 = tcg_temp_new_i64();
+                    tcg_gen_ld_i64(tmp64, cpu_env, ri->fieldoffset);
+                }
+                tmp = tcg_temp_new_i32();
+                tcg_gen_trunc_i64_i32(tmp, tmp64);
+                store_reg(s, rt, tmp);
+                tcg_gen_shri_i64(tmp64, tmp64, 32);
+                tcg_gen_trunc_i64_i32(tmp, tmp64);
+                store_reg(s, rt2, tmp);
+            } else {
+                TCGv tmp;
+                if (ri->type & ARM_CP_CONST) {
+                    tmp = tcg_const_i32(ri->resetvalue);
+                } else if (ri->readfn) {
+                    TCGv_ptr tmpptr;
+                    gen_set_pc_im(s->pc);
+                    tmp = tcg_temp_new_i32();
+                    tmpptr = tcg_const_ptr(ri);
+                    gen_helper_get_cp_reg(tmp, cpu_env, tmpptr);
+                    tcg_temp_free_ptr(tmpptr);
+                } else {
+                    tmp = load_cpu_offset(ri->fieldoffset);
+                }
+                if (rt == 15) {
+                    /* Destination register of r15 for 32 bit loads sets
+                     * the condition codes from the high 4 bits of the value
+                     */
+                    gen_set_nzcv(tmp);
+                    tcg_temp_free_i32(tmp);
+                } else {
+                    store_reg(s, rt, tmp);
+                }
+            }
+        } else {
+            /* Write */
+            if (ri->type & ARM_CP_CONST) {
+                /* If not forbidden by access permissions, treat as WI */
+                return 0;
+            }
+
+            if (is64) {
+                TCGv tmplo, tmphi;
+                TCGv_i64 tmp64 = tcg_temp_new_i64();
+                tmplo = load_reg(s, rt);
+                tmphi = load_reg(s, rt2);
+                tcg_gen_concat_i32_i64(tmp64, tmplo, tmphi);
+                tcg_temp_free_i32(tmplo);
+                tcg_temp_free_i32(tmphi);
+                if (ri->writefn) {
+                    TCGv_ptr tmpptr = tcg_const_ptr(ri);
+                    gen_set_pc_im(s->pc);
+                    gen_helper_set_cp_reg64(cpu_env, tmpptr, tmp64);
+                    tcg_temp_free_ptr(tmpptr);
+                } else {
+                    tcg_gen_st_i64(tmp64, cpu_env, ri->fieldoffset);
+                }
+                tcg_temp_free_i64(tmp64);
+            } else {
+                if (ri->writefn) {
+                    TCGv tmp;
+                    TCGv_ptr tmpptr;
+                    gen_set_pc_im(s->pc);
+                    tmp = load_reg(s, rt);
+                    tmpptr = tcg_const_ptr(ri);
+                    gen_helper_set_cp_reg(cpu_env, tmpptr, tmp);
+                    tcg_temp_free_ptr(tmpptr);
+                    tcg_temp_free_i32(tmp);
+                } else {
+                    TCGv tmp = load_reg(s, rt);
+                    store_cpu_offset(tmp, ri->fieldoffset);
+                }
+            }
+            /* We default to ending the TB on a coprocessor register write,
+             * but allow this to be suppressed by the register definition
+             * (usually only necessary to work around guest bugs).
+             */
+            if (!(ri->type & ARM_CP_SUPPRESS_TB_END)) {
+                gen_lookup_tb(s);
+            }
+        }
+        return 0;
+    }
+
+    /* Fallback code: handle coprocessor registers not yet converted
+     * to ARMCPRegInfo.
+     */
+    switch (cpnum) {
     case 14:
         /* Coprocessors 7-15 are architecturally reserved by ARM.
            Unfortunately Intel decided to ignore this.  */