ahci: Add some MMIO debug printfs

These are useful for bringup of AHCI.
Signed-off-by: NPeter Crosthwaite <crosthwaite.peter@gmail.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Message-id: 517ba413dce7deb4ab17c0cc1e8bbdaaace2a0db.1445917756.git.crosthwaite.peter@gmail.com
Signed-off-by: NJohn Snow <jsnow@redhat.com>

hw/ide/ahci.c

@@ -378,17 +378,23 @@ static uint64_t ahci_mem_read(void *opaque, hwaddr addr, unsigned size)
     int ofst = addr - aligned;
     uint64_t lo = ahci_mem_read_32(opaque, aligned);
     uint64_t hi;
+    uint64_t val;
 
     /* if < 8 byte read does not cross 4 byte boundary */
     if (ofst + size <= 4) {
-        return lo >> (ofst * 8);
+        val = lo >> (ofst * 8);
+    } else {
+        g_assert_cmpint(size, >, 1);
+
+        /* If the 64bit read is unaligned, we will produce undefined
+         * results. AHCI does not support unaligned 64bit reads. */
+        hi = ahci_mem_read_32(opaque, aligned + 4);
+        val = (hi << 32 | lo) >> (ofst * 8);
     }
-    g_assert_cmpint(size, >, 1);
 
-    /* If the 64bit read is unaligned, we will produce undefined
-     * results. AHCI does not support unaligned 64bit reads. */
-    hi = ahci_mem_read_32(opaque, aligned + 4);
-    return (hi << 32 | lo) >> (ofst * 8);
+    DPRINTF(-1, "addr=0x%" HWADDR_PRIx " val=0x%" PRIx64 ", size=%d\n",
+            addr, val, size);
+    return val;
 }
 
 
@@ -397,6 +403,9 @@ static void ahci_mem_write(void *opaque, hwaddr addr,
 {
     AHCIState *s = opaque;
 
+    DPRINTF(-1, "addr=0x%" HWADDR_PRIx " val=0x%" PRIx64 ", size=%d\n",
+            addr, val, size);
+
     /* Only aligned reads are allowed on AHCI */
     if (addr & 3) {
         fprintf(stderr, "ahci: Mis-aligned write to addr 0x"