arm/arm64: smccc: Make function identifiers an unsigned quantity

Marc Zyngier · ctmarinas · commit ded4c39e93f3 · 2018-02-06T22:54:13.000Z
Function identifiers are a 32bit, unsigned quantity. But we never
tell so to the compiler, resulting in the following:

 4ac:   b26187e0        mov     x0, #0xffffffff80000001

We thus rely on the firmware narrowing it for us, which is not
always a reasonable expectation.

Cc: stable@vger.kernel.org
Reported-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Acked-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Tested-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
@@ -14,14 +14,16 @@
 #ifndef __LINUX_ARM_SMCCC_H
 #define __LINUX_ARM_SMCCC_H
 
+#include <uapi/linux/const.h>
+
 /*
  * This file provides common defines for ARM SMC Calling Convention as
  * specified in
  * http://infocenter.arm.com/help/topic/com.arm.doc.den0028a/index.html
  */
 
-#define ARM_SMCCC_STD_CALL		0
-#define ARM_SMCCC_FAST_CALL		1
+#define ARM_SMCCC_STD_CALL	        _AC(0,U)
+#define ARM_SMCCC_FAST_CALL	        _AC(1,U)
 #define ARM_SMCCC_TYPE_SHIFT		31
 
 #define ARM_SMCCC_SMC_32		0
