refactor(amu): factor out register accesses

This change introduces a small set of register getters and setters to
avoid having to repeatedly mask and shift in complex code.

Change-Id: Ia372f60c5efb924cd6eeceb75112e635ad13d942
Signed-off-by: Chris Kay <chris.kay@arm.com>
diff --git a/include/arch/aarch32/arch.h b/include/arch/aarch32/arch.h
index 7221b62..59680b7 100644
--- a/include/arch/aarch32/arch.h
+++ b/include/arch/aarch32/arch.h
@@ -253,7 +253,8 @@
 /* HCPTR definitions */
 #define HCPTR_RES1		((U(1) << 13) | (U(1) << 12) | U(0x3ff))
 #define TCPAC_BIT		(U(1) << 31)
-#define TAM_BIT			(U(1) << 30)
+#define TAM_SHIFT		U(30)
+#define TAM_BIT			(U(1) << TAM_SHIFT)
 #define TTA_BIT			(U(1) << 20)
 #define TCP11_BIT		(U(1) << 11)
 #define TCP10_BIT		(U(1) << 10)
@@ -727,8 +728,25 @@
 #define AMEVTYPER1E	p15, 0, c13, c15, 6
 #define AMEVTYPER1F	p15, 0, c13, c15, 7
 
+/* AMCNTENSET0 definitions */
+#define AMCNTENSET0_Pn_SHIFT	U(0)
+#define AMCNTENSET0_Pn_MASK	U(0xffff)
+
+/* AMCNTENSET1 definitions */
+#define AMCNTENSET1_Pn_SHIFT	U(0)
+#define AMCNTENSET1_Pn_MASK	U(0xffff)
+
+/* AMCNTENCLR0 definitions */
+#define AMCNTENCLR0_Pn_SHIFT	U(0)
+#define AMCNTENCLR0_Pn_MASK	U(0xffff)
+
+/* AMCNTENCLR1 definitions */
+#define AMCNTENCLR1_Pn_SHIFT	U(0)
+#define AMCNTENCLR1_Pn_MASK	U(0xffff)
+
 /* AMCR definitions */
-#define AMCR_CG1RZ_BIT		(ULL(1) << 17)
+#define AMCR_CG1RZ_SHIFT	U(17)
+#define AMCR_CG1RZ_BIT		(ULL(1) << AMCR_CG1RZ_SHIFT)
 
 /* AMCFGR definitions */
 #define AMCFGR_NCG_SHIFT	U(28)