feat(pauth): add/modify helpers to support QARMA3

QARMA3 is a pointer authentication algorithm that generates
the PAC codes.

The is_armv8_3_pauth_present() helper was modified in order to
consider the presence of the QARMA3 algorithm (i.e.: when
ID_AA64ISAR2_EL1.{GPA3, APA3} fields are not 0.

In addition, helper is_feat_pacqarma3_present() was implemented to
explicitly detect the presence of QARMA3 algorithm.

Signed-off-by: Juan Pablo Conde <juanpablo.conde@arm.com>
Change-Id: I68e8fa7f8b7ca50d74ae0a2f5f182236d68f3d7b

include/arch/aarch64/arch.h

@@ -261,6 +261,15 @@
 #define ID_AA64ISAR1_SB_SUPPORTED	ULL(0x1)
 #define ID_AA64ISAR1_SB_NOT_SUPPORTED	ULL(0x0)
 
+/* ID_AA64ISAR2_EL1 definitions */
+#define ID_AA64ISAR2_EL1		S3_0_C0_C6_2
+
+#define ID_AA64ISAR2_GPA3_SHIFT		U(8)
+#define ID_AA64ISAR2_GPA3_MASK		ULL(0xf)
+
+#define ID_AA64ISAR2_APA3_SHIFT		U(12)
+#define ID_AA64ISAR2_APA3_MASK		ULL(0xf)
+
 /* ID_AA64MMFR0_EL1 definitions */
 #define ID_AA64MMFR0_EL1_PARANGE_SHIFT	U(0)
 #define ID_AA64MMFR0_EL1_PARANGE_MASK	ULL(0xf)

include/arch/aarch64/arch_features.h

@@ -35,15 +35,30 @@ static inline bool is_armv8_2_ttcnp_present(void)
 		ID_AA64MMFR2_EL1_CNP_MASK) != 0U;
 }
 
+static inline bool is_feat_pacqarma3_present(void)
+{
+	uint64_t mask_id_aa64isar2 =
+			(ID_AA64ISAR2_GPA3_MASK << ID_AA64ISAR2_GPA3_SHIFT) |
+			(ID_AA64ISAR2_APA3_MASK << ID_AA64ISAR2_APA3_SHIFT);
+
+	/* If any of the fields is not zero, QARMA3 algorithm is present */
+	return (read_id_aa64isar2_el1() & mask_id_aa64isar2) != 0U;
+}
+
 static inline bool is_armv8_3_pauth_present(void)
 {
-	uint64_t mask = (ID_AA64ISAR1_GPI_MASK << ID_AA64ISAR1_GPI_SHIFT) |
+	uint64_t mask_id_aa64isar1 =
+		(ID_AA64ISAR1_GPI_MASK << ID_AA64ISAR1_GPI_SHIFT) |
 		(ID_AA64ISAR1_GPA_MASK << ID_AA64ISAR1_GPA_SHIFT) |
 		(ID_AA64ISAR1_API_MASK << ID_AA64ISAR1_API_SHIFT) |
 		(ID_AA64ISAR1_APA_MASK << ID_AA64ISAR1_APA_SHIFT);
 
-	/* If any of the fields is not zero, PAuth is present */
-	return (read_id_aa64isar1_el1() & mask) != 0U;
+	/*
+	 * If any of the fields is not zero or QARMA3 is present,
+	 * PAuth is present
+	 */
+	return ((read_id_aa64isar1_el1() & mask_id_aa64isar1) != 0U ||
+		is_feat_pacqarma3_present());
 }
 
 static inline bool is_armv8_4_dit_present(void)

include/arch/aarch64/arch_helpers.h

@@ -250,6 +250,7 @@ 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_RENAME_SYSREG_READ_FUNC(id_aa64isar2_el1, ID_AA64ISAR2_EL1)
 DEFINE_SYSREG_READ_FUNC(id_aa64pfr0_el1)
 DEFINE_SYSREG_READ_FUNC(id_aa64pfr1_el1)
 DEFINE_SYSREG_READ_FUNC(id_aa64dfr0_el1)