Factor address_space_is_io() out of cpu_physical_memory_is_io().

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/system/memory.h |  9 +++++++++
 system/physmem.c        | 21 ++++++++++++---------
 2 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/include/system/memory.h b/include/system/memory.h
index aa85fc27a10..1b2b0e5ce1e 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -3029,6 +3029,15 @@ static inline MemoryRegion *address_space_translate(AddressSpace *as,
 bool address_space_access_valid(AddressSpace *as, hwaddr addr, hwaddr len,
                                 bool is_write, MemTxAttrs attrs);
 
+/**
+ * address_space_is_io: check whether an guest physical addresses
+ *                      whithin an address space is I/O memory.
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ */
+bool address_space_is_io(AddressSpace *as, hwaddr addr);
+
 /* address_space_map: map a physical memory region into a host virtual address
  *
  * May map a subset of the requested range, given by and returned in @plen.
diff --git a/system/physmem.c b/system/physmem.c
index 225ab817883..c2829ab407a 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3358,6 +3358,17 @@ bool address_space_access_valid(AddressSpace *as, hwaddr addr,
     return flatview_access_valid(fv, addr, len, is_write, attrs);
 }
 
+bool address_space_is_io(AddressSpace *as, hwaddr addr)
+{
+    MemoryRegion *mr;
+
+    RCU_READ_LOCK_GUARD();
+    mr = address_space_translate(as, addr, &addr, NULL, false,
+                                 MEMTXATTRS_UNSPECIFIED);
+
+    return !(memory_region_is_ram(mr) || memory_region_is_romd(mr));
+}
+
 static hwaddr
 flatview_extend_translation(FlatView *fv, hwaddr addr,
                             hwaddr target_len,
@@ -3754,15 +3765,7 @@ int cpu_memory_rw_debug(CPUState *cpu, vaddr addr,
 
 bool cpu_physical_memory_is_io(hwaddr phys_addr)
 {
-    MemoryRegion*mr;
-    hwaddr l = 1;
-
-    RCU_READ_LOCK_GUARD();
-    mr = address_space_translate(&address_space_memory,
-                                 phys_addr, &phys_addr, &l, false,
-                                 MEMTXATTRS_UNSPECIFIED);
-
-    return !(memory_region_is_ram(mr) || memory_region_is_romd(mr));
+    return address_space_is_io(&address_space_memory, phys_addr);
 }
 
 int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque)
-- 
2.51.0