From: Alistair Francis <alistair.francis@xilinx.com>
Date: Mon, 4 Jul 2016 12:06:36 +0000 (+0100)
Subject: bitops: Add MAKE_64BIT_MASK macro
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ae2923b5c20a21c6457680330506a9c13873485c;p=qemu.git

bitops: Add MAKE_64BIT_MASK macro

Add a macro that creates a 64bit value which has length number of ones
shifted across by the value of shift.

Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 9773244aa1c8c26b8b82cb261d8f5dd4b7b9fcf9.1467053537.git.alistair.francis@xilinx.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---

diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h
index 15418a86df..98fb005aba 100644
--- a/include/qemu/bitops.h
+++ b/include/qemu/bitops.h
@@ -24,6 +24,9 @@
 #define BIT_WORD(nr)            ((nr) / BITS_PER_LONG)
 #define BITS_TO_LONGS(nr)       DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
 
+#define MAKE_64BIT_MASK(shift, length) \
+    (((~0ULL) >> (64 - (length))) << (shift))
+
 /**
  * set_bit - Set a bit in memory
  * @nr: the bit to set