[Qemu-devel] [PATCH v2 07/20] memory: Access MemoryRegion with MemOp

[<tony.nguyen@bt.com>]

Replacing size with size+sign+endianness (MemOp) will enable us to
collapse the two byte swaps, adjust_endianness and handle_bswap, along
the I/O path.

While interfaces are converted, callers will have existing unsigned
size coerced into a MemOp, and the callee will use this MemOp as an
unsigned size.

Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
---
 include/exec/memop.h  | 4 ++++
 include/exec/memory.h | 9 +++++----
 memory.c              | 7 +++++--
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/include/exec/memop.h b/include/exec/memop.h
index 43e99d7..73f1bf7 100644
--- a/include/exec/memop.h
+++ b/include/exec/memop.h
@@ -24,4 +24,8 @@ typedef enum MemOp {
     MO_BSWAP = 8,   /* Host reverse endian.  */
 } MemOp;

+/* No-op while memory_region_dispatch_[read|write] is converted to MemOp */
+#define MEMOP_SIZE(op)  (op)    /* MemOp to size.  */
+#define SIZE_MEMOP(ul)  (ul)    /* Size to MemOp.  */
+
 #endif
diff --git a/include/exec/memory.h b/include/exec/memory.h
index bb0961d..30b1c58 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -19,6 +19,7 @@
 #include "exec/cpu-common.h"
 #include "exec/hwaddr.h"
 #include "exec/memattrs.h"
+#include "exec/memop.h"
 #include "exec/ramlist.h"
 #include "qemu/queue.h"
 #include "qemu/int128.h"
@@ -1731,13 +1732,13 @@ void mtree_info(bool flatview, bool dispatch_tree, bool owner);
  * @mr: #MemoryRegion to access
  * @addr: address within that region
  * @pval: pointer to uint64_t which the data is written to
- * @size: size of the access in bytes
+ * @op: encodes size of the access in bytes
  * @attrs: memory transaction attributes to use for the access
  */
 MemTxResult memory_region_dispatch_read(MemoryRegion *mr,
                                         hwaddr addr,
                                         uint64_t *pval,
-                                        unsigned size,
+                                        MemOp op,
                                         MemTxAttrs attrs);
 /**
  * memory_region_dispatch_write: perform a write directly to the specified
@@ -1746,13 +1747,13 @@ MemTxResult memory_region_dispatch_read(MemoryRegion *mr,
  * @mr: #MemoryRegion to access
  * @addr: address within that region
  * @data: data to write
- * @size: size of the access in bytes
+ * @op: encodes size of the access in bytes
  * @attrs: memory transaction attributes to use for the access
  */
 MemTxResult memory_region_dispatch_write(MemoryRegion *mr,
                                          hwaddr addr,
                                          uint64_t data,
-                                         unsigned size,
+                                         MemOp op,
                                          MemTxAttrs attrs);

 /**
diff --git a/memory.c b/memory.c
index d4579bb..73cb345 100644
--- a/memory.c
+++ b/memory.c
@@ -1437,10 +1437,11 @@ static MemTxResult memory_region_dispatch_read1(MemoryRegion *mr,
 MemTxResult memory_region_dispatch_read(MemoryRegion *mr,
                                         hwaddr addr,
                                         uint64_t *pval,
-                                        unsigned size,
+                                        MemOp op,
                                         MemTxAttrs attrs)
 {
     MemTxResult r;
+    unsigned size = MEMOP_SIZE(op);

     if (!memory_region_access_valid(mr, addr, size, false, attrs)) {
         *pval = unassigned_mem_read(mr, addr, size);
@@ -1481,9 +1482,11 @@ static bool memory_region_dispatch_write_eventfds(MemoryRegion *mr,
 MemTxResult memory_region_dispatch_write(MemoryRegion *mr,
                                          hwaddr addr,
                                          uint64_t data,
-                                         unsigned size,
+                                         MemOp op,
                                          MemTxAttrs attrs)
 {
+    unsigned size = MEMOP_SIZE(op);
+
     if (!memory_region_access_valid(mr, addr, size, true, attrs)) {
         unassigned_mem_write(mr, addr, data, size);
         return MEMTX_DECODE_ERROR;
--
1.8.3.1