hw/core: Introduce CPUClass.gdb_adjust_breakpoint

This will allow a breakpoint hack to move out of AVR's translator.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

cpu.c

@@ -267,8 +267,13 @@ static void breakpoint_invalidate(CPUState *cpu, target_ulong pc)
 int cpu_breakpoint_insert(CPUState *cpu, vaddr pc, int flags,
                           CPUBreakpoint **breakpoint)
 {
+    CPUClass *cc = CPU_GET_CLASS(cpu);
     CPUBreakpoint *bp;
 
+    if (cc->gdb_adjust_breakpoint) {
+        pc = cc->gdb_adjust_breakpoint(cpu, pc);
+    }
+
     bp = g_malloc(sizeof(*bp));
 
     bp->pc = pc;
@@ -294,8 +299,13 @@ int cpu_breakpoint_insert(CPUState *cpu, vaddr pc, int flags,
 /* Remove a specific breakpoint.  */
 int cpu_breakpoint_remove(CPUState *cpu, vaddr pc, int flags)
 {
+    CPUClass *cc = CPU_GET_CLASS(cpu);
     CPUBreakpoint *bp;
 
+    if (cc->gdb_adjust_breakpoint) {
+        pc = cc->gdb_adjust_breakpoint(cpu, pc);
+    }
+
     QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
         if (bp->pc == pc && bp->flags == flags) {
             cpu_breakpoint_remove_by_ref(cpu, bp);

include/hw/core/cpu.h

@@ -103,6 +103,9 @@ struct SysemuCPUOps;
  *       also implement the synchronize_from_tb hook.
  * @gdb_read_register: Callback for letting GDB read a register.
  * @gdb_write_register: Callback for letting GDB write a register.
+ * @gdb_adjust_breakpoint: Callback for adjusting the address of a
+ *       breakpoint.  Used by AVR to handle a gdb mis-feature with
+ *       its Harvard architecture split code and data.
  * @gdb_num_core_regs: Number of core registers accessible to GDB.
  * @gdb_core_xml_file: File name for core registers GDB XML description.
  * @gdb_stop_before_watchpoint: Indicates whether GDB expects the CPU to stop
@@ -137,6 +140,7 @@ struct CPUClass {
     void (*set_pc)(CPUState *cpu, vaddr value);
     int (*gdb_read_register)(CPUState *cpu, GByteArray *buf, int reg);
     int (*gdb_write_register)(CPUState *cpu, uint8_t *buf, int reg);
+    vaddr (*gdb_adjust_breakpoint)(CPUState *cpu, vaddr addr);
 
     const char *gdb_core_xml_file;
     gchar * (*gdb_arch_name)(CPUState *cpu);