[PATCH v2 09/11] ArmPkg: Prevent SgiId from setting RES0 bits of GICD_SGIR

["Sami Mujawar" <sami.mujawar@arm.com>]

GICD_SGIR is a 32-bit register, of which INTID is bits [3:0]
and Bits [14:4] is RES0. Since SgiId parameter in the function
ArmGicSendSgiTo () is UINT8, mask unused bits of SgiId before
writing to the GICD_SGIR register to prevent accidental setting
of the RES0 bits.

Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
---

Notes:
    v2:
     - Updated copyright year                             [Sami]

 ArmPkg/Drivers/ArmGic/ArmGicLib.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ArmPkg/Drivers/ArmGic/ArmGicLib.c b/ArmPkg/Drivers/ArmGic/ArmGicLib.c
index eefe6350eb804bf9b2727b605d59035877ffb817..0127cca3bf0567bc80702f415e9cbb9bd2709fbc 100644
--- a/ArmPkg/Drivers/ArmGic/ArmGicLib.c
+++ b/ArmPkg/Drivers/ArmGic/ArmGicLib.c
@@ -148,7 +148,9 @@ ArmGicSendSgiTo (
 {
   MmioWrite32 (
     GicDistributorBase + ARM_GIC_ICDSGIR,
-    ((TargetListFilter & 0x3) << 24) | ((CPUTargetList & 0xFF) << 16) | SgiId
+    ((TargetListFilter & 0x3) << 24) |
+    ((CPUTargetList & 0xFF) << 16)   |
+    (SgiId & 0xF)
     );
 }
 
-- 
'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'