arm64/cpufeature: Introduce ID_MMFR5 CPU register

This adds basic building blocks required for ID_MMFR5 CPU register which
provides information about the implemented memory model and memory
management support in AArch32 state. This is added per ARM DDI 0487F.a
specification.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/1589881254-10082-7-git-send-email-anshuman.khandual@arm.comSigned-off-by: Will Deacon <will@kernel.org>

arch/arm64/include/asm/cpu.h

@@ -45,6 +45,7 @@ struct cpuinfo_arm64 {
 	u32		reg_id_mmfr1;
 	u32		reg_id_mmfr2;
 	u32		reg_id_mmfr3;
+	u32		reg_id_mmfr5;
 	u32		reg_id_pfr0;
 	u32		reg_id_pfr1;
 	u32		reg_id_pfr2;

arch/arm64/include/asm/sysreg.h

@@ -147,6 +147,7 @@
 #define SYS_ID_MMFR2_EL1		sys_reg(3, 0, 0, 1, 6)
 #define SYS_ID_MMFR3_EL1		sys_reg(3, 0, 0, 1, 7)
 #define SYS_ID_MMFR4_EL1		sys_reg(3, 0, 0, 2, 6)
+#define SYS_ID_MMFR5_EL1		sys_reg(3, 0, 0, 3, 6)
 
 #define SYS_ID_ISAR0_EL1		sys_reg(3, 0, 0, 2, 0)
 #define SYS_ID_ISAR1_EL1		sys_reg(3, 0, 0, 2, 1)
@@ -793,6 +794,8 @@
 #define ID_ISAR6_DP_SHIFT		4
 #define ID_ISAR6_JSCVT_SHIFT		0
 
+#define ID_MMFR5_ETS_SHIFT		0
+
 #define ID_PFR2_SSBS_SHIFT		4
 #define ID_PFR2_CSV3_SHIFT		0
 

arch/arm64/kernel/cpufeature.c

@@ -408,6 +408,11 @@ static const struct arm64_ftr_bits ftr_id_isar4[] = {
 	ARM64_FTR_END,
 };
 
+static const struct arm64_ftr_bits ftr_id_mmfr5[] = {
+	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR5_ETS_SHIFT, 4, 0),
+	ARM64_FTR_END,
+};
+
 static const struct arm64_ftr_bits ftr_id_isar6[] = {
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_I8MM_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_BF16_SHIFT, 4, 0),
@@ -533,6 +538,7 @@ static const struct __ftr_reg_entry {
 	ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
 	ARM64_FTR_REG(SYS_ID_PFR2_EL1, ftr_id_pfr2),
 	ARM64_FTR_REG(SYS_ID_DFR1_EL1, ftr_id_dfr1),
+	ARM64_FTR_REG(SYS_ID_MMFR5_EL1, ftr_id_mmfr5),
 
 	/* Op1 = 0, CRn = 0, CRm = 4 */
 	ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
@@ -738,6 +744,7 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
 		init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
 		init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
 		init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
+		init_cpu_ftr_reg(SYS_ID_MMFR5_EL1, info->reg_id_mmfr5);
 		init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
 		init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
 		init_cpu_ftr_reg(SYS_ID_PFR2_EL1, info->reg_id_pfr2);
@@ -872,6 +879,8 @@ static int update_32bit_cpu_features(int cpu, struct cpuinfo_arm64 *info,
 				      info->reg_id_mmfr2, boot->reg_id_mmfr2);
 	taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
 				      info->reg_id_mmfr3, boot->reg_id_mmfr3);
+	taint |= check_update_ftr_reg(SYS_ID_MMFR5_EL1, cpu,
+				      info->reg_id_mmfr5, boot->reg_id_mmfr5);
 	taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
 				      info->reg_id_pfr0, boot->reg_id_pfr0);
 	taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
@@ -1012,6 +1021,7 @@ static u64 __read_sysreg_by_encoding(u32 sys_id)
 	read_sysreg_case(SYS_ID_MMFR1_EL1);
 	read_sysreg_case(SYS_ID_MMFR2_EL1);
 	read_sysreg_case(SYS_ID_MMFR3_EL1);
+	read_sysreg_case(SYS_ID_MMFR5_EL1);
 	read_sysreg_case(SYS_ID_ISAR0_EL1);
 	read_sysreg_case(SYS_ID_ISAR1_EL1);
 	read_sysreg_case(SYS_ID_ISAR2_EL1);

arch/arm64/kernel/cpuinfo.c

@@ -374,6 +374,7 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
 		info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
 		info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
 		info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
+		info->reg_id_mmfr5 = read_cpuid(ID_MMFR5_EL1);
 		info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
 		info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
 		info->reg_id_pfr2 = read_cpuid(ID_PFR2_EL1);

arch/arm64/kvm/sys_regs.c

@@ -1458,7 +1458,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	ID_UNALLOCATED(3,3),
 	ID_SANITISED(ID_PFR2_EL1),
 	ID_HIDDEN(ID_DFR1_EL1),
-	ID_UNALLOCATED(3,6),
+	ID_SANITISED(ID_MMFR5_EL1),
 	ID_UNALLOCATED(3,7),
 
 	/* AArch64 ID registers */