Define registers for FEAT_RNG support

Add ISAR0 feature register read helper, location
of FEAT_RNG bits, feature support helper and the
rndr/rndrrs register read helpers.
Signed-off-by: Tomas Pilar <tomas@nuviainc.com>
Change-Id: I2a785a36f62a917548e55892ce92fa8b72fcb99d

include/arch/aarch64/arch.h

@@ -193,6 +193,10 @@
 #define ID_AA64DFR0_MTPMU_MASK		ULL(0xf)
 #define ID_AA64DFR0_MTPMU_SUPPORTED	ULL(1)
 
+/* ID_AA64ISAR0_EL1 definitions */
+#define ID_AA64ISAR0_RNDR_SHIFT U(60)
+#define ID_AA64ISAR0_RNDR_MASK  ULL(0xf)
+
 /* ID_AA64ISAR1_EL1 definitions */
 #define ID_AA64ISAR1_EL1	S3_0_C0_C6_1
 #define ID_AA64ISAR1_GPI_SHIFT	U(28)

include/arch/aarch64/arch_features.h

@@ -76,6 +76,12 @@ static inline unsigned long int get_armv8_6_ecv_support(void)
 		ID_AA64MMFR0_EL1_ECV_MASK);
 }
 
+static inline bool is_armv8_5_rng_present(void)
+{
+	return ((read_id_aa64isar0_el1() >> ID_AA64ISAR0_RNDR_SHIFT) &
+		ID_AA64ISAR0_RNDR_MASK);
+}
+
 /*
  * Return MPAM version:
  *

include/arch/aarch64/arch_helpers.h

@@ -245,6 +245,7 @@ void disable_mmu_icache_el3(void);
 
 DEFINE_SYSREG_RW_FUNCS(par_el1)
 DEFINE_SYSREG_READ_FUNC(id_pfr1_el1)
+DEFINE_SYSREG_READ_FUNC(id_aa64isar0_el1)
 DEFINE_SYSREG_READ_FUNC(id_aa64isar1_el1)
 DEFINE_SYSREG_READ_FUNC(id_aa64pfr0_el1)
 DEFINE_SYSREG_READ_FUNC(id_aa64pfr1_el1)
@@ -522,6 +523,10 @@ DEFINE_RENAME_SYSREG_RW_FUNCS(tfsr_el1, TFSR_EL1)
 DEFINE_RENAME_SYSREG_RW_FUNCS(rgsr_el1, RGSR_EL1)
 DEFINE_RENAME_SYSREG_RW_FUNCS(gcr_el1, GCR_EL1)
 
+/* Armv8.5 FEAT_RNG Registers */
+DEFINE_SYSREG_READ_FUNC(rndr)
+DEFINE_SYSREG_READ_FUNC(rndrrs)
+
 /* DynamIQ Shared Unit power management */
 DEFINE_RENAME_SYSREG_RW_FUNCS(clusterpwrdn_el1, CLUSTERPWRDN_EL1)