[coreboot-gerrit] Change in coreboot[master]: mmio: Use unsigned types for bit operations

[Hung-Te Lin (Code Review)]

Hung-Te Lin has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/40404 )

Change subject: mmio: Use unsigned types for bit operations
......................................................................

mmio: Use unsigned types for bit operations

When declaring bit fields with 31 bits (e.g: DEFINE_BITFIELD(MYREG, 30, 0) )
the calculation of mask value will go overflow (
 "error: integer overflow in expression '-2147483648 - 1' of type 'int'
  Results in '2147483647'").

To fix that, we want to bit field macros to always use unsigned
integers.

Change-Id: Ie3cddf9df60b83de4e21243bfde6b79729fb06ef
Changr-Id: Ib165700edba6f26fb885fad15c0e483bcb6a63a9
Signed-off-by: Hung-Te Lin 
---
M src/include/device/mmio.h
1 file changed, 2 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/04/40404/1

diff --git a/src/include/device/mmio.h b/src/include/device/mmio.h
index 524284a..374c8ac 100644
--- a/src/include/device/mmio.h
+++ b/src/include/device/mmio.h
@@ -142,10 +142,10 @@
 #define DEFINE_BIT(name, bit) DEFINE_BITFIELD(name, bit, bit)

#define _BF_MASK(name, value) \
-	(((1 << name##_BITFIELD_SIZE) - 1) << name##_BITFIELD_SHIFT)
+	(((1U << name##_BITFIELD_SIZE) - 1) << name##_BITFIELD_SHIFT)

#define _BF_VALUE(name, value) \
-	((value) << name##_BITFIELD_SHIFT)
+	((unsigned int)(value) << name##_BITFIELD_SHIFT)

#define _BF_APPLY1(op, name, value, ...) (op(name, value))
 #define _BF_APPLY2(op, name, value, ...) ((op(name, value)) | \