tcg: TCGMemOp is now accelerator independent MemOp

Preparation for collapsing the two byte swaps, adjust_endianness and
handle_bswap, along the I/O path.

Target dependant attributes are conditionalized upon NEED_CPU_H.

Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <81d9cd7d7f5aaadfa772d6c48ecee834e9cf7882.1566466906.git.tony.nguyen@bt.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

include/exec/memop.h

@@ -0,0 +1,110 @@
+/*
+ * Constants for memory operations
+ *
+ * Authors:
+ *  Richard Henderson <rth@twiddle.net>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef MEMOP_H
+#define MEMOP_H
+
+typedef enum MemOp {
+    MO_8     = 0,
+    MO_16    = 1,
+    MO_32    = 2,
+    MO_64    = 3,
+    MO_SIZE  = 3,   /* Mask for the above.  */
+
+    MO_SIGN  = 4,   /* Sign-extended, otherwise zero-extended.  */
+
+    MO_BSWAP = 8,   /* Host reverse endian.  */
+#ifdef HOST_WORDS_BIGENDIAN
+    MO_LE    = MO_BSWAP,
+    MO_BE    = 0,
+#else
+    MO_LE    = 0,
+    MO_BE    = MO_BSWAP,
+#endif
+#ifdef NEED_CPU_H
+#ifdef TARGET_WORDS_BIGENDIAN
+    MO_TE    = MO_BE,
+#else
+    MO_TE    = MO_LE,
+#endif
+#endif
+
+    /*
+     * MO_UNALN accesses are never checked for alignment.
+     * MO_ALIGN accesses will result in a call to the CPU's
+     * do_unaligned_access hook if the guest address is not aligned.
+     * The default depends on whether the target CPU defines
+     * TARGET_ALIGNED_ONLY.
+     *
+     * Some architectures (e.g. ARMv8) need the address which is aligned
+     * to a size more than the size of the memory access.
+     * Some architectures (e.g. SPARCv9) need an address which is aligned,
+     * but less strictly than the natural alignment.
+     *
+     * MO_ALIGN supposes the alignment size is the size of a memory access.
+     *
+     * There are three options:
+     * - unaligned access permitted (MO_UNALN).
+     * - an alignment to the size of an access (MO_ALIGN);
+     * - an alignment to a specified size, which may be more or less than
+     *   the access size (MO_ALIGN_x where 'x' is a size in bytes);
+     */
+    MO_ASHIFT = 4,
+    MO_AMASK = 7 << MO_ASHIFT,
+#ifdef NEED_CPU_H
+#ifdef TARGET_ALIGNED_ONLY
+    MO_ALIGN = 0,
+    MO_UNALN = MO_AMASK,
+#else
+    MO_ALIGN = MO_AMASK,
+    MO_UNALN = 0,
+#endif
+#endif
+    MO_ALIGN_2  = 1 << MO_ASHIFT,
+    MO_ALIGN_4  = 2 << MO_ASHIFT,
+    MO_ALIGN_8  = 3 << MO_ASHIFT,
+    MO_ALIGN_16 = 4 << MO_ASHIFT,
+    MO_ALIGN_32 = 5 << MO_ASHIFT,
+    MO_ALIGN_64 = 6 << MO_ASHIFT,
+
+    /* Combinations of the above, for ease of use.  */
+    MO_UB    = MO_8,
+    MO_UW    = MO_16,
+    MO_UL    = MO_32,
+    MO_SB    = MO_SIGN | MO_8,
+    MO_SW    = MO_SIGN | MO_16,
+    MO_SL    = MO_SIGN | MO_32,
+    MO_Q     = MO_64,
+
+    MO_LEUW  = MO_LE | MO_UW,
+    MO_LEUL  = MO_LE | MO_UL,
+    MO_LESW  = MO_LE | MO_SW,
+    MO_LESL  = MO_LE | MO_SL,
+    MO_LEQ   = MO_LE | MO_Q,
+
+    MO_BEUW  = MO_BE | MO_UW,
+    MO_BEUL  = MO_BE | MO_UL,
+    MO_BESW  = MO_BE | MO_SW,
+    MO_BESL  = MO_BE | MO_SL,
+    MO_BEQ   = MO_BE | MO_Q,
+
+#ifdef NEED_CPU_H
+    MO_TEUW  = MO_TE | MO_UW,
+    MO_TEUL  = MO_TE | MO_UL,
+    MO_TESW  = MO_TE | MO_SW,
+    MO_TESL  = MO_TE | MO_SL,
+    MO_TEQ   = MO_TE | MO_Q,
+#endif
+
+    MO_SSIZE = MO_SIZE | MO_SIGN,
+} MemOp;
+
+#endif