tcg: Remove needless CPUState::current_tb

This field was used for telling cpu_interrupt() to unlink a chain of TBs
being executed when it worked that way. Now, cpu_interrupt() don't do
this anymore. So we don't need this field anymore.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1462273462-14036-1-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>

cpu-exec-common.c

@@ -68,7 +68,6 @@ void cpu_reloading_memory_map(void)
 
 void cpu_loop_exit(CPUState *cpu)
 {
-    cpu->current_tb = NULL;
     siglongjmp(cpu->jmp_env, 1);
 }
 
@@ -77,6 +76,5 @@ void cpu_loop_exit_restore(CPUState *cpu, uintptr_t pc)
     if (pc) {
         cpu_restore_state(cpu, pc);
     }
-    cpu->current_tb = NULL;
     siglongjmp(cpu->jmp_env, 1);
 }

cpu-exec.c

@@ -216,11 +216,9 @@ static void cpu_exec_nocache(CPUState *cpu, int max_cycles,
                          | (ignore_icount ? CF_IGNORE_ICOUNT : 0));
     tb->orig_tb = cpu->tb_flushed ? NULL : orig_tb;
     cpu->tb_flushed |= old_tb_flushed;
-    cpu->current_tb = tb;
     /* execute the generated code */
     trace_exec_tb_nocache(tb, tb->pc);
     cpu_tb_exec(cpu, tb);
-    cpu->current_tb = NULL;
     tb_phys_invalidate(tb, -1);
     tb_free(tb);
 }
@@ -532,9 +530,7 @@ int cpu_exec(CPUState *cpu)
                     uintptr_t ret;
                     trace_exec_tb(tb, tb->pc);
                     /* execute the generated code */
-                    cpu->current_tb = tb;
                     ret = cpu_tb_exec(cpu, tb);
-                    cpu->current_tb = NULL;
                     last_tb = (TranslationBlock *)(ret & ~TB_EXIT_MASK);
                     tb_exit = ret & TB_EXIT_MASK;
                     switch (tb_exit) {

cputlb.c

@@ -76,10 +76,6 @@ void tlb_flush(CPUState *cpu, int flush_global)
 
     tlb_debug("(%d)\n", flush_global);
 
-    /* must reset current TB so that interrupts cannot modify the
-       links while we are modifying them */
-    cpu->current_tb = NULL;
-
     memset(env->tlb_table, -1, sizeof(env->tlb_table));
     memset(env->tlb_v_table, -1, sizeof(env->tlb_v_table));
     memset(cpu->tb_jmp_cache, 0, sizeof(cpu->tb_jmp_cache));
@@ -95,9 +91,6 @@ static inline void v_tlb_flush_by_mmuidx(CPUState *cpu, va_list argp)
     CPUArchState *env = cpu->env_ptr;
 
     tlb_debug("start\n");
-    /* must reset current TB so that interrupts cannot modify the
-       links while we are modifying them */
-    cpu->current_tb = NULL;
 
     for (;;) {
         int mmu_idx = va_arg(argp, int);
@@ -152,9 +145,6 @@ void tlb_flush_page(CPUState *cpu, target_ulong addr)
         tlb_flush(cpu, 1);
         return;
     }
-    /* must reset current TB so that interrupts cannot modify the
-       links while we are modifying them */
-    cpu->current_tb = NULL;
 
     addr &= TARGET_PAGE_MASK;
     i = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
@@ -193,9 +183,6 @@ void tlb_flush_page_by_mmuidx(CPUState *cpu, target_ulong addr, ...)
         va_end(argp);
         return;
     }
-    /* must reset current TB so that interrupts cannot modify the
-       links while we are modifying them */
-    cpu->current_tb = NULL;
 
     addr &= TARGET_PAGE_MASK;
     i = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);

hw/i386/kvmvapic.c

@@ -446,7 +446,6 @@ static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip)
     resume_all_vcpus();
 
     if (!kvm_enabled()) {
-        cs->current_tb = NULL;
         tb_gen_code(cs, current_pc, current_cs_base, current_flags, 1);
         cpu_resume_from_signal(cs, NULL);
     }

include/qom/cpu.h

@@ -253,7 +253,6 @@ struct kvm_run;
  * @as: Pointer to the first AddressSpace, for the convenience of targets which
  *      only have a single AddressSpace
  * @env_ptr: Pointer to subclass-specific CPUArchState field.
- * @current_tb: Currently executing TB.
  * @gdb_regs: Additional GDB registers.
  * @gdb_num_regs: Number of total registers accessible to GDB.
  * @gdb_num_g_regs: Number of registers in GDB 'g' packets.
@@ -305,7 +304,6 @@ struct CPUState {
     MemoryRegion *memory;
 
     void *env_ptr; /* CPUArchState */
-    struct TranslationBlock *current_tb;
     struct TranslationBlock *tb_jmp_cache[TB_JMP_CACHE_SIZE];
     struct GDBRegisterState *gdb_regs;
     int gdb_num_regs;

qom/cpu.c

@@ -254,7 +254,6 @@ static void cpu_common_reset(CPUState *cpu)
     }
 
     cpu->interrupt_request = 0;
-    cpu->current_tb = NULL;
     cpu->halted = 0;
     cpu->mem_io_pc = 0;
     cpu->mem_io_vaddr = 0;

translate-all.c

@@ -305,7 +305,6 @@ bool cpu_restore_state(CPUState *cpu, uintptr_t retaddr)
         cpu_restore_state_from_tb(cpu, tb, retaddr);
         if (tb->cflags & CF_NOCACHE) {
             /* one-shot translation, invalidate it immediately */
-            cpu->current_tb = NULL;
             tb_phys_invalidate(tb, -1);
             tb_free(tb);
         }
@@ -1309,9 +1308,9 @@ void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end)
 void tb_invalidate_phys_page_range(tb_page_addr_t start, tb_page_addr_t end,
                                    int is_cpu_write_access)
 {
-    TranslationBlock *tb, *tb_next, *saved_tb;
+    TranslationBlock *tb, *tb_next;
-    CPUState *cpu = current_cpu;
 #if defined(TARGET_HAS_PRECISE_SMC)
+    CPUState *cpu = current_cpu;
     CPUArchState *env = NULL;
 #endif
     tb_page_addr_t tb_start, tb_end;
@@ -1378,20 +1377,7 @@ void tb_invalidate_phys_page_range(tb_page_addr_t start, tb_page_addr_t end,
                                      &current_flags);
             }
 #endif /* TARGET_HAS_PRECISE_SMC */
-            /* we need to do that to handle the case where a signal
-               occurs while doing tb_phys_invalidate() */
-            saved_tb = NULL;
-            if (cpu != NULL) {
-                saved_tb = cpu->current_tb;
-                cpu->current_tb = NULL;
-            }
             tb_phys_invalidate(tb, -1);
-            if (cpu != NULL) {
-                cpu->current_tb = saved_tb;
-                if (cpu->interrupt_request && cpu->current_tb) {
-                    cpu_interrupt(cpu, cpu->interrupt_request);
-                }
-            }
         }
         tb = tb_next;
     }
@@ -1407,7 +1393,6 @@ void tb_invalidate_phys_page_range(tb_page_addr_t start, tb_page_addr_t end,
         /* we generate a block containing just the instruction
            modifying the memory. It will ensure that it cannot modify
            itself */
-        cpu->current_tb = NULL;
         tb_gen_code(cpu, current_pc, current_cs_base, current_flags, 1);
         cpu_resume_from_signal(cpu, NULL);
     }
@@ -1512,7 +1497,6 @@ static void tb_invalidate_phys_page(tb_page_addr_t addr,
         /* we generate a block containing just the instruction
            modifying the memory. It will ensure that it cannot modify
            itself */
-        cpu->current_tb = NULL;
         tb_gen_code(cpu, current_pc, current_cs_base, current_flags, 1);
         if (locked) {
             mmap_unlock();