Change in coreboot[master]: nb/intel/gm45: Guard `CxDRBy_BOUND_SHIFT` macro parameters

[Angel Pons (Code Review)]

Angel Pons has submitted this change. ( https://review.coreboot.org/c/coreboot/+/49261 )

Change subject: nb/intel/gm45: Guard `CxDRBy_BOUND_SHIFT` macro parameters
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nb/intel/gm45: Guard `CxDRBy_BOUND_SHIFT` macro parameters

Wrap `r` in parentheses to avoid unexpected behavior with compound
expressions. This prevents `CxDRBy_BOUND_MB(r+1, base)` from triggering
undefined behavior when `r = 2`, as the shift would be greater than 32.

Change-Id: I14235b2708ab502d842da677451c14203a469b45
Signed-off-by: Angel Pons 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49261
Reviewed-by: Nico Huber 
Tested-by: build bot (Jenkins) 
---
M src/northbridge/intel/gm45/gm45.h
1 file changed, 1 insertion(+), 1 deletion(-)

Approvals:
  build bot (Jenkins): Verified
  Nico Huber: Looks good to me, approved

diff --git a/src/northbridge/intel/gm45/gm45.h b/src/northbridge/intel/gm45/gm45.h
index 4d8a923..11eeaa5 100644
--- a/src/northbridge/intel/gm45/gm45.h
+++ b/src/northbridge/intel/gm45/gm45.h
@@ -274,7 +274,7 @@
  * All registers (4 ranks per channel) have to be set.
  */
 #define CxDRBy_MCHBAR(x, r)	(0x1200 + (x * 0x0100) + ((r / 2) * 4))
-#define CxDRBy_BOUND_SHIFT(r)	((r % 2) * 16)
+#define CxDRBy_BOUND_SHIFT(r)	(((r) % 2) * 16)
 #define CxDRBy_BOUND_MASK(r)	(0x1fc << CxDRBy_BOUND_SHIFT(r))
 #define CxDRBy_BOUND_MB(r, b)	/* for boundary in MB b */ \
    (((b >> 5) << CxDRBy_BOUND_SHIFT(r)) & CxDRBy_BOUND_MASK(r))