[stable:PATCH v5.4.184 03/22] arm64: add ID_AA64ISAR2_EL1 sys register

[James Morse <james.morse@arm.com>]

From: Joey Gouly <joey.gouly@arm.com>

commit 9e45365f1469ef2b934f9d035975dbc9ad352116 upstream.

This is a new ID register, introduced in 8.7.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Reiji Watanabe <reijiw@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211210165432.8106-3-joey.gouly@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
---
 arch/arm64/include/asm/cpu.h    |  1 +
 arch/arm64/include/asm/sysreg.h | 15 +++++++++++++++
 arch/arm64/kernel/cpufeature.c  |  9 +++++++++
 arch/arm64/kernel/cpuinfo.c     |  1 +
 arch/arm64/kvm/sys_regs.c       |  2 +-
 5 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h
index d72d995b7e25..85cc06380e93 100644
--- a/arch/arm64/include/asm/cpu.h
+++ b/arch/arm64/include/asm/cpu.h
@@ -25,6 +25,7 @@ struct cpuinfo_arm64 {
 	u64		reg_id_aa64dfr1;
 	u64		reg_id_aa64isar0;
 	u64		reg_id_aa64isar1;
+	u64		reg_id_aa64isar2;
 	u64		reg_id_aa64mmfr0;
 	u64		reg_id_aa64mmfr1;
 	u64		reg_id_aa64mmfr2;
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 9b68f1b3915e..50ed2747c572 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -165,6 +165,7 @@
 
 #define SYS_ID_AA64ISAR0_EL1		sys_reg(3, 0, 0, 6, 0)
 #define SYS_ID_AA64ISAR1_EL1		sys_reg(3, 0, 0, 6, 1)
+#define SYS_ID_AA64ISAR2_EL1		sys_reg(3, 0, 0, 6, 2)
 
 #define SYS_ID_AA64MMFR0_EL1		sys_reg(3, 0, 0, 7, 0)
 #define SYS_ID_AA64MMFR1_EL1		sys_reg(3, 0, 0, 7, 1)
@@ -575,6 +576,20 @@
 #define ID_AA64ISAR1_GPI_NI		0x0
 #define ID_AA64ISAR1_GPI_IMP_DEF	0x1
 
+/* id_aa64isar2 */
+#define ID_AA64ISAR2_RPRES_SHIFT	4
+#define ID_AA64ISAR2_WFXT_SHIFT		0
+
+#define ID_AA64ISAR2_RPRES_8BIT		0x0
+#define ID_AA64ISAR2_RPRES_12BIT	0x1
+/*
+ * Value 0x1 has been removed from the architecture, and is
+ * reserved, but has not yet been removed from the ARM ARM
+ * as of ARM DDI 0487G.b.
+ */
+#define ID_AA64ISAR2_WFXT_NI		0x0
+#define ID_AA64ISAR2_WFXT_SUPPORTED	0x2
+
 /* id_aa64pfr0 */
 #define ID_AA64PFR0_CSV3_SHIFT		60
 #define ID_AA64PFR0_CSV2_SHIFT		56
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index acdef8d76c64..6b77e4942495 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -150,6 +150,10 @@ static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
 	ARM64_FTR_END,
 };
 
+static const struct arm64_ftr_bits ftr_id_aa64isar2[] = {
+	ARM64_FTR_END,
+};
+
 static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV3_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV2_SHIFT, 4, 0),
@@ -410,6 +414,7 @@ static const struct __ftr_reg_entry {
 	/* Op1 = 0, CRn = 0, CRm = 6 */
 	ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
 	ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1),
+	ARM64_FTR_REG(SYS_ID_AA64ISAR2_EL1, ftr_id_aa64isar2),
 
 	/* Op1 = 0, CRn = 0, CRm = 7 */
 	ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
@@ -581,6 +586,7 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
 	init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
 	init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
 	init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
+	init_cpu_ftr_reg(SYS_ID_AA64ISAR2_EL1, info->reg_id_aa64isar2);
 	init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
 	init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
 	init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2);
@@ -704,6 +710,8 @@ void update_cpu_features(int cpu,
 				      info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
 				      info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
+	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR2_EL1, cpu,
+				      info->reg_id_aa64isar2, boot->reg_id_aa64isar2);
 
 	/*
 	 * Differing PARange support is fine as long as all peripherals and
@@ -838,6 +846,7 @@ static u64 __read_sysreg_by_encoding(u32 sys_id)
 	read_sysreg_case(SYS_ID_AA64MMFR2_EL1);
 	read_sysreg_case(SYS_ID_AA64ISAR0_EL1);
 	read_sysreg_case(SYS_ID_AA64ISAR1_EL1);
+	read_sysreg_case(SYS_ID_AA64ISAR2_EL1);
 
 	read_sysreg_case(SYS_CNTFRQ_EL0);
 	read_sysreg_case(SYS_CTR_EL0);
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 05933c065732..90b35011a22f 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -344,6 +344,7 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
 	info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1);
 	info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
 	info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
+	info->reg_id_aa64isar2 = read_cpuid(ID_AA64ISAR2_EL1);
 	info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
 	info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
 	info->reg_id_aa64mmfr2 = read_cpuid(ID_AA64MMFR2_EL1);
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index da649e90240c..a25f737dfa0b 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1454,7 +1454,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	/* CRm=6 */
 	ID_SANITISED(ID_AA64ISAR0_EL1),
 	ID_SANITISED(ID_AA64ISAR1_EL1),
-	ID_UNALLOCATED(6,2),
+	ID_SANITISED(ID_AA64ISAR2_EL1),
 	ID_UNALLOCATED(6,3),
 	ID_UNALLOCATED(6,4),
 	ID_UNALLOCATED(6,5),
-- 
2.30.2