accel/tcg: Introduce translator_io_start

New wrapper around gen_io_start which takes care of the USE_ICOUNT
check, as well as marking the DisasContext to end the TB.
Remove exec/gen-icount.h.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

MAINTAINERS

@@ -2867,7 +2867,6 @@ F: ui/cocoa.m
 Main loop
 M: Paolo Bonzini <pbonzini@redhat.com>
 S: Maintained
-F: include/exec/gen-icount.h
 F: include/qemu/main-loop.h
 F: include/sysemu/runstate.h
 F: include/sysemu/runstate-action.h

accel/tcg/translator.c

@@ -12,20 +12,43 @@
 #include "tcg/tcg.h"
 #include "tcg/tcg-op.h"
 #include "exec/exec-all.h"
-#include "exec/gen-icount.h"
 #include "exec/log.h"
 #include "exec/translator.h"
 #include "exec/plugin-gen.h"
 #include "exec/replay-core.h"
 
 
-void gen_io_start(void)
+static void gen_io_start(void)
 {
     tcg_gen_st_i32(tcg_constant_i32(1), cpu_env,
                    offsetof(ArchCPU, parent_obj.can_do_io) -
                    offsetof(ArchCPU, env));
 }
 
+bool translator_io_start(DisasContextBase *db)
+{
+    uint32_t cflags = tb_cflags(db->tb);
+
+    if (!(cflags & CF_USE_ICOUNT)) {
+        return false;
+    }
+    if (db->num_insns == db->max_insns && (cflags & CF_LAST_IO)) {
+        /* Already started in translator_loop. */
+        return true;
+    }
+
+    gen_io_start();
+
+    /*
+     * Ensure that this instruction will be the last in the TB.
+     * The target may override this to something more forceful.
+     */
+    if (db->is_jmp == DISAS_NEXT) {
+        db->is_jmp = DISAS_TOO_MANY;
+    }
+    return true;
+}
+
 static TCGOp *gen_tb_start(uint32_t cflags)
 {
     TCGv_i32 count = tcg_temp_new_i32();

include/exec/gen-icount.h

@@ -1,6 +0,0 @@
-#ifndef GEN_ICOUNT_H
-#define GEN_ICOUNT_H
-
-void gen_io_start(void);
-
-#endif

include/exec/translator.h

@@ -160,6 +160,16 @@ void translator_loop(CPUState *cpu, TranslationBlock *tb, int *max_insns,
  */
 bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest);
 
+/**
+ * translator_io_start
+ * @db: Disassembly context
+ *
+ * If icount is enabled, set cpu->can_to_io, adjust db->is_jmp to
+ * DISAS_TOO_MANY if it is still DISAS_NEXT, and return true.
+ * Otherwise return false.
+ */
+bool translator_io_start(DisasContextBase *db);
+
 /*
  * Translator Load Functions
  *

target/alpha/translate.c

@@ -96,8 +96,6 @@ static TCGv cpu_lock_value;
 static TCGv cpu_pal_ir[31];
 #endif
 
-#include "exec/gen-icount.h"
-
 void alpha_translate_init(void)
 {
 #define DEF_VAR(V)  { &cpu_##V, #V, offsetof(CPUAlphaState, V) }
@@ -1236,8 +1234,7 @@ static DisasJumpType gen_mfpr(DisasContext *ctx, TCGv va, int regno)
     case 249: /* VMTIME */
         helper = gen_helper_get_vmtime;
     do_helper:
-        if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+        if (translator_io_start(&ctx->base)) {
-            gen_io_start();
             helper(va);
             return DISAS_PC_STALE;
         } else {
@@ -1298,8 +1295,7 @@ static DisasJumpType gen_mtpr(DisasContext *ctx, TCGv vb, int regno)
 
     case 251:
         /* ALARM */
-        if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+        if (translator_io_start(&ctx->base)) {
-            gen_io_start();
             ret = DISAS_PC_STALE;
         }
         gen_helper_set_alarm(cpu_env, vb);
@@ -2335,13 +2331,10 @@ static DisasJumpType translate_one(DisasContext *ctx, uint32_t insn)
         case 0xC000:
             /* RPCC */
             va = dest_gpr(ctx, ra);
-            if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+            if (translator_io_start(&ctx->base)) {
-                gen_io_start();
-                gen_helper_load_pcc(va, cpu_env);
                 ret = DISAS_PC_STALE;
-            } else {
-                gen_helper_load_pcc(va, cpu_env);
             }
+            gen_helper_load_pcc(va, cpu_env);
             break;
         case 0xE000:
             /* RC */

target/arm/cpregs.h

@@ -67,8 +67,8 @@ enum {
     ARM_CP_ALIAS                 = 1 << 8,
     /*
      * Flag: Register does I/O and therefore its accesses need to be marked
-     * with gen_io_start() and also end the TB. In particular, registers which
+     * with translator_io_start() and also end the TB. In particular,
-     * implement clocks or timers require this.
+     * registers which implement clocks or timers require this.
      */
     ARM_CP_IO                    = 1 << 9,
     /*

target/arm/tcg/translate-a64.c

@@ -28,7 +28,6 @@
 #include "internals.h"
 #include "qemu/host-utils.h"
 #include "semihosting/semihost.h"
-#include "exec/gen-icount.h"
 #include "exec/log.h"
 #include "cpregs.h"
 #include "translate-a64.h"
@@ -1552,9 +1551,7 @@ static bool trans_ERET(DisasContext *s, arg_ERET *a)
     tcg_gen_ld_i64(dst, cpu_env,
                    offsetof(CPUARMState, elr_el[s->current_el]));
 
-    if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+    translator_io_start(&s->base);
-        gen_io_start();
-    }
 
     gen_helper_exception_return(cpu_env, dst);
     /* Must exit loop to check un-masked IRQs */
@@ -1582,9 +1579,8 @@ static bool trans_ERETA(DisasContext *s, arg_reta *a)
                    offsetof(CPUARMState, elr_el[s->current_el]));
 
     dst = auth_branch_target(s, dst, cpu_X[31], !a->m);
-    if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+
-        gen_io_start();
+    translator_io_start(&s->base);
-    }
 
     gen_helper_exception_return(cpu_env, dst);
     /* Must exit loop to check un-masked IRQs */
@@ -2044,6 +2040,7 @@ static void handle_sys(DisasContext *s, uint32_t insn, bool isread,
     uint32_t key = ENCODE_AA64_CP_REG(CP_REG_ARM64_SYSREG_CP,
                                       crn, crm, op0, op1, op2);
     const ARMCPRegInfo *ri = get_arm_cp_reginfo(s->cp_regs, key);
+    bool need_exit_tb = false;
     TCGv_ptr tcg_ri = NULL;
     TCGv_i64 tcg_rt;
 
@@ -2171,8 +2168,9 @@ static void handle_sys(DisasContext *s, uint32_t insn, bool isread,
         return;
     }
 
-    if ((tb_cflags(s->base.tb) & CF_USE_ICOUNT) && (ri->type & ARM_CP_IO)) {
+    if (ri->type & ARM_CP_IO) {
-        gen_io_start();
+        /* I/O operations must end the TB here (whether read or write) */
+        need_exit_tb = translator_io_start(&s->base);
     }
 
     tcg_rt = cpu_reg(s, rt);
@@ -2202,10 +2200,6 @@ static void handle_sys(DisasContext *s, uint32_t insn, bool isread,
         }
     }
 
-    if ((tb_cflags(s->base.tb) & CF_USE_ICOUNT) && (ri->type & ARM_CP_IO)) {
-        /* I/O operations must end the TB here (whether read or write) */
-        s->base.is_jmp = DISAS_UPDATE_EXIT;
-    }
     if (!isread && !(ri->type & ARM_CP_SUPPRESS_TB_END)) {
         /*
          * A write to any coprocessor regiser that ends a TB
@@ -2217,6 +2211,9 @@ static void handle_sys(DisasContext *s, uint32_t insn, bool isread,
          * but allow this to be suppressed by the register definition
          * (usually only necessary to work around guest bugs).
          */
+        need_exit_tb = true;
+    }
+    if (need_exit_tb) {
         s->base.is_jmp = DISAS_UPDATE_EXIT;
     }
 }

target/arm/tcg/translate-mve.c

@@ -21,7 +21,6 @@
 #include "tcg/tcg-op.h"
 #include "tcg/tcg-op-gvec.h"
 #include "exec/exec-all.h"
-#include "exec/gen-icount.h"
 #include "translate.h"
 #include "translate-a32.h"
 

target/arm/tcg/translate-neon.c

@@ -24,7 +24,6 @@
 #include "tcg/tcg-op.h"
 #include "tcg/tcg-op-gvec.h"
 #include "exec/exec-all.h"
-#include "exec/gen-icount.h"
 #include "translate.h"
 #include "translate-a32.h"
 

target/arm/tcg/translate-vfp.c

@@ -24,7 +24,6 @@
 #include "tcg/tcg-op.h"
 #include "tcg/tcg-op-gvec.h"
 #include "exec/exec-all.h"
-#include "exec/gen-icount.h"
 #include "translate.h"
 #include "translate-a32.h"
 
@@ -117,9 +116,8 @@ static void gen_preserve_fp_state(DisasContext *s, bool skip_context_update)
          * so we must mark it as an IO operation for icount (and cause
          * this to be the last insn in the TB).
          */
-        if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+        if (translator_io_start(&s->base)) {
             s->base.is_jmp = DISAS_UPDATE_EXIT;
-            gen_io_start();
         }
         gen_helper_v7m_preserve_fp_state(cpu_env);
         /*

target/arm/tcg/translate.c

@@ -34,7 +34,6 @@
 #include "cpregs.h"
 #include "translate.h"
 #include "translate-a32.h"
-#include "exec/gen-icount.h"
 #include "exec/helper-proto.h"
 
 #define HELPER_H "helper.h"
@@ -2908,9 +2907,7 @@ static void gen_rfe(DisasContext *s, TCGv_i32 pc, TCGv_i32 cpsr)
      * appropriately depending on the new Thumb bit, so it must
      * be called after storing the new PC.
      */
-    if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+    translator_io_start(&s->base);
-        gen_io_start();
-    }
     gen_helper_cpsr_write_eret(cpu_env, cpsr);
     /* Must exit loop to check un-masked IRQs */
     s->base.is_jmp = DISAS_EXIT;
@@ -4559,7 +4556,7 @@ static void do_coproc_insn(DisasContext *s, int cpnum, int is64,
     uint32_t key = ENCODE_CP_REG(cpnum, is64, s->ns, crn, crm, opc1, opc2);
     const ARMCPRegInfo *ri = get_arm_cp_reginfo(s->cp_regs, key);
     TCGv_ptr tcg_ri = NULL;
-    bool need_exit_tb;
+    bool need_exit_tb = false;
     uint32_t syndrome;
 
     /*
@@ -4704,8 +4701,9 @@ static void do_coproc_insn(DisasContext *s, int cpnum, int is64,
         g_assert_not_reached();
     }
 
-    if ((tb_cflags(s->base.tb) & CF_USE_ICOUNT) && (ri->type & ARM_CP_IO)) {
+    if (ri->type & ARM_CP_IO) {
-        gen_io_start();
+        /* I/O operations must end the TB here (whether read or write) */
+        need_exit_tb = translator_io_start(&s->base);
     }
 
     if (isread) {
@@ -4787,10 +4785,6 @@ static void do_coproc_insn(DisasContext *s, int cpnum, int is64,
         }
     }
 
-    /* I/O operations must end the TB here (whether read or write) */
-    need_exit_tb = ((tb_cflags(s->base.tb) & CF_USE_ICOUNT) &&
-                    (ri->type & ARM_CP_IO));
-
     if (!isread && !(ri->type & ARM_CP_SUPPRESS_TB_END)) {
         /*
          * A write to any coprocessor register that ends a TB
@@ -8047,9 +8041,7 @@ static bool do_ldm(DisasContext *s, arg_ldst_block *a, int min_n)
     if (exc_return) {
         /* Restore CPSR from SPSR.  */
         tmp = load_cpu_field(spsr);
-        if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+        translator_io_start(&s->base);
-            gen_io_start();
-        }
         gen_helper_cpsr_write_eret(cpu_env, tmp);
         /* Must exit loop to check un-masked IRQs */
         s->base.is_jmp = DISAS_EXIT;

target/avr/translate.c

@@ -29,7 +29,6 @@
 #include "exec/helper-gen.h"
 #include "exec/log.h"
 #include "exec/translator.h"
-#include "exec/gen-icount.h"
 
 #define HELPER_H "helper.h"
 #include "exec/helper-info.c.inc"

target/cris/translate.c

@@ -88,8 +88,6 @@ static TCGv env_btaken;
 static TCGv env_btarget;
 static TCGv env_pc;
 
-#include "exec/gen-icount.h"
-
 /* This is the state at translation time.  */
 typedef struct DisasContext {
     DisasContextBase base;

target/hppa/translate.c

@@ -364,8 +364,6 @@ static TCGv_reg cpu_psw_v;
 static TCGv_reg cpu_psw_cb;
 static TCGv_reg cpu_psw_cb_msb;
 
-#include "exec/gen-icount.h"
-
 void hppa_translate_init(void)
 {
 #define DEF_VAR(V)  { &cpu_##V, #V, offsetof(CPUHPPAState, V) }
@@ -2090,8 +2088,7 @@ static bool trans_mfctl(DisasContext *ctx, arg_mfctl *a)
         /* FIXME: Respect PSW_S bit.  */
         nullify_over(ctx);
         tmp = dest_gpr(ctx, rt);
-        if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+        if (translator_io_start(&ctx->base)) {
-            gen_io_start();
             gen_helper_read_interval_timer(tmp);
             ctx->base.is_jmp = DISAS_IAQ_N_STALE;
         } else {

target/i386/tcg/translate.c

@@ -78,8 +78,6 @@ static TCGv cpu_seg_base[6];
 static TCGv_i64 cpu_bndl[4];
 static TCGv_i64 cpu_bndu[4];
 
-#include "exec/gen-icount.h"
-
 typedef struct DisasContext {
     DisasContextBase base;
 
@@ -3933,10 +3931,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
                 !(s->cpuid_ext_features & CPUID_EXT_RDRAND)) {
                 goto illegal_op;
             }
-            if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+            translator_io_start(&s->base);
-                gen_io_start();
-                s->base.is_jmp = DISAS_TOO_MANY;
-            }
             gen_helper_rdrand(s->T0, cpu_env);
             rm = (modrm & 7) | REX_B(s);
             gen_op_mov_reg_v(s, dflag, rm, s->T0);
@@ -4974,10 +4969,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
                           SVM_IOIO_TYPE_MASK | SVM_IOIO_STR_MASK)) {
             break;
         }
-        if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+        translator_io_start(&s->base);
-            gen_io_start();
-            s->base.is_jmp = DISAS_TOO_MANY;
-        }
         if (prefixes & (PREFIX_REPZ | PREFIX_REPNZ)) {
             gen_repz_ins(s, ot);
         } else {
@@ -4992,10 +4984,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
         if (!gen_check_io(s, ot, s->tmp2_i32, SVM_IOIO_STR_MASK)) {
             break;
         }
-        if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+        translator_io_start(&s->base);
-            gen_io_start();
-            s->base.is_jmp = DISAS_TOO_MANY;
-        }
         if (prefixes & (PREFIX_REPZ | PREFIX_REPNZ)) {
             gen_repz_outs(s, ot);
         } else {
@@ -5014,10 +5003,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
         if (!gen_check_io(s, ot, s->tmp2_i32, SVM_IOIO_TYPE_MASK)) {
             break;
         }
-        if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+        translator_io_start(&s->base);
-            gen_io_start();
-            s->base.is_jmp = DISAS_TOO_MANY;
-        }
         gen_helper_in_func(ot, s->T1, s->tmp2_i32);
         gen_op_mov_reg_v(s, ot, R_EAX, s->T1);
         gen_bpt_io(s, s->tmp2_i32, ot);
@@ -5030,10 +5016,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
         if (!gen_check_io(s, ot, s->tmp2_i32, 0)) {
             break;
         }
-        if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+        translator_io_start(&s->base);
-            gen_io_start();
-            s->base.is_jmp = DISAS_TOO_MANY;
-        }
         gen_op_mov_v_reg(s, ot, s->T1, R_EAX);
         tcg_gen_trunc_tl_i32(s->tmp3_i32, s->T1);
         gen_helper_out_func(ot, s->tmp2_i32, s->tmp3_i32);
@@ -5047,10 +5030,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
         if (!gen_check_io(s, ot, s->tmp2_i32, SVM_IOIO_TYPE_MASK)) {
             break;
         }
-        if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+        translator_io_start(&s->base);
-            gen_io_start();
-            s->base.is_jmp = DISAS_TOO_MANY;
-        }
         gen_helper_in_func(ot, s->T1, s->tmp2_i32);
         gen_op_mov_reg_v(s, ot, R_EAX, s->T1);
         gen_bpt_io(s, s->tmp2_i32, ot);
@@ -5063,10 +5043,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
         if (!gen_check_io(s, ot, s->tmp2_i32, 0)) {
             break;
         }
-        if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+        translator_io_start(&s->base);
-            gen_io_start();
-            s->base.is_jmp = DISAS_TOO_MANY;
-        }
         gen_op_mov_v_reg(s, ot, s->T1, R_EAX);
         tcg_gen_trunc_tl_i32(s->tmp3_i32, s->T1);
         gen_helper_out_func(ot, s->tmp2_i32, s->tmp3_i32);
@@ -5674,10 +5651,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
     case 0x131: /* rdtsc */
         gen_update_cc_op(s);
         gen_update_eip_cur(s);
-        if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+        translator_io_start(&s->base);
-            gen_io_start();
-            s->base.is_jmp = DISAS_TOO_MANY;
-        }
         gen_helper_rdtsc(cpu_env);
         break;
     case 0x133: /* rdpmc */
@@ -6133,10 +6107,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
             }
             gen_update_cc_op(s);
             gen_update_eip_cur(s);
-            if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+            translator_io_start(&s->base);
-                gen_io_start();
-                s->base.is_jmp = DISAS_TOO_MANY;
-            }
             gen_helper_rdtscp(cpu_env);
             break;
 
@@ -6490,10 +6461,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
         }
         ot  = (CODE64(s) ? MO_64 : MO_32);
 
-        if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
+        translator_io_start(&s->base);
-            gen_io_start();
-            s->base.is_jmp = DISAS_TOO_MANY;
-        }
         if (b & 2) {
             gen_svm_check_intercept(s, SVM_EXIT_WRITE_CR0 + reg);
             gen_op_mov_v_reg(s, ot, s->T0, rm);

target/loongarch/insn_trans/trans_extra.c.inc

@@ -39,9 +39,7 @@ static bool gen_rdtime(DisasContext *ctx, arg_rr *a,
     TCGv dst1 = gpr_dst(ctx, a->rd, EXT_NONE);
     TCGv dst2 = gpr_dst(ctx, a->rj, EXT_NONE);
 
-    if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+    translator_io_start(&ctx->base);
-        gen_io_start();
-    }
     gen_helper_rdtime_d(dst1, cpu_env);
     if (word) {
         tcg_gen_sextract_tl(dst1, dst1, high ? 32 : 0, 32);

target/loongarch/insn_trans/trans_privileged.c.inc

@@ -185,9 +185,7 @@ static bool check_csr_flags(DisasContext *ctx, const CSRInfo *csr, bool write)
     if ((csr->flags & CSRFL_READONLY) && write) {
         return false;
     }
-    if ((csr->flags & CSRFL_IO) &&
+    if ((csr->flags & CSRFL_IO) && translator_io_start(&ctx->base)) {
-        (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT)) {
-        gen_io_start();
         ctx->base.is_jmp = DISAS_EXIT_UPDATE;
     } else if ((csr->flags & CSRFL_EXITTB) && write) {
         ctx->base.is_jmp = DISAS_EXIT_UPDATE;

target/loongarch/translate.c

@@ -24,8 +24,6 @@
 TCGv cpu_gpr[32], cpu_pc;
 static TCGv cpu_lladdr, cpu_llval;
 
-#include "exec/gen-icount.h"
-
 #define HELPER_H "helper.h"
 #include "exec/helper-info.c.inc"
 #undef  HELPER_H

target/m68k/translate.c

@@ -65,8 +65,6 @@ static TCGv NULL_QREG;
 /* Used to distinguish stores from bad addressing modes.  */
 static TCGv store_dummy;
 
-#include "exec/gen-icount.h"
-
 void m68k_tcg_init(void)
 {
     char *p;

target/microblaze/translate.c

@@ -58,8 +58,6 @@ static TCGv_i32 cpu_iflags;
 static TCGv cpu_res_addr;
 static TCGv_i32 cpu_res_val;
 
-#include "exec/gen-icount.h"
-
 /* This is the state at translation time.  */
 typedef struct DisasContext {
     DisasContextBase base;