arm64/cpufeature: Add remaining feature bits in ID_MMFR4 register

Enable all remaining feature bits like EVT, CCIDX, LSM, HPDS, CnP, XNX,
SpecSEI in ID_MMFR4 register per ARM DDI 0487F.a.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/1589881254-10082-9-git-send-email-anshuman.khandual@arm.comSigned-off-by: Will Deacon <will@kernel.org>

arch/arm64/include/asm/sysreg.h

@@ -794,6 +794,14 @@
 #define ID_ISAR6_DP_SHIFT		4
 #define ID_ISAR6_JSCVT_SHIFT		0
 
+#define ID_MMFR4_EVT_SHIFT		28
+#define ID_MMFR4_CCIDX_SHIFT		24
+#define ID_MMFR4_LSM_SHIFT		20
+#define ID_MMFR4_HPDS_SHIFT		16
+#define ID_MMFR4_CNP_SHIFT		12
+#define ID_MMFR4_XNX_SHIFT		8
+#define ID_MMFR4_SPECSEI_SHIFT		0
+
 #define ID_MMFR5_ETS_SHIFT		0
 
 #define ID_PFR0_DIT_SHIFT		24

arch/arm64/kernel/cpufeature.c

@@ -392,7 +392,20 @@ static const struct arm64_ftr_bits ftr_id_isar5[] = {
 };
 
 static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
+	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EVT_SHIFT, 4, 0),
+	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CCIDX_SHIFT, 4, 0),
+	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_LSM_SHIFT, 4, 0),
+	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_HPDS_SHIFT, 4, 0),
+	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CNP_SHIFT, 4, 0),
+	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_XNX_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),	/* ac2 */
+	/*
+	 * SpecSEI = 1 indicates that the PE might generate an SError on an
+	 * external abort on speculative read. It is safe to assume that an
+	 * SError might be generated than it will not be. Hence it has been
+	 * classified as FTR_HIGHER_SAFE.
+	 */
+	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_MMFR4_SPECSEI_SHIFT, 4, 0),
 	ARM64_FTR_END,
 };