[PATCH v1 05/16] arm64: Helper for parange to PASize

[Suzuki K Poulose <suzuki.poulose@arm.com>]

Add a helper to convert ID_AA64MMFR0_EL1:PARange to they physical
size shift. Limit the size to the maximum supported by the kernel.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 arch/arm64/include/asm/cpufeature.h | 16 ++++++++++++++++
 arch/arm64/kvm/hyp/s2-setup.c       | 28 +++++-----------------------
 2 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index ac67cfc2585a..0564e14616eb 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -304,6 +304,22 @@ static inline u64 read_zcr_features(void)
 	return zcr;
 }
 
+static inline u32 id_aa64mmfr0_parange_to_phys_shift(int parange)
+{
+	switch (parange) {
+	case 0: return 32;
+	case 1: return 36;
+	case 2: return 40;
+	case 3: return 42;
+	case 4: return 44;
+
+	default:
+	case 5: return 48;
+#ifdef CONFIG_ARM64_PA_BITS_52
+	case 6: return 52;
+#endif
+	}
+}
 #endif /* __ASSEMBLY__ */
 
 #endif
diff --git a/arch/arm64/kvm/hyp/s2-setup.c b/arch/arm64/kvm/hyp/s2-setup.c
index 603e1ee83e89..b1129c83c531 100644
--- a/arch/arm64/kvm/hyp/s2-setup.c
+++ b/arch/arm64/kvm/hyp/s2-setup.c
@@ -19,11 +19,13 @@
 #include <asm/kvm_arm.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_hyp.h>
+#include <asm/cpufeature.h>
 
 u32 __hyp_text __init_stage2_translation(void)
 {
 	u64 val = VTCR_EL2_FLAGS;
 	u64 parange;
+	u32 phys_shift;
 	u64 tmp;
 
 	/*
@@ -37,27 +39,7 @@ u32 __hyp_text __init_stage2_translation(void)
 	val |= parange << 16;
 
 	/* Compute the actual PARange... */
-	switch (parange) {
-	case 0:
-		parange = 32;
-		break;
-	case 1:
-		parange = 36;
-		break;
-	case 2:
-		parange = 40;
-		break;
-	case 3:
-		parange = 42;
-		break;
-	case 4:
-		parange = 44;
-		break;
-	case 5:
-	default:
-		parange = 48;
-		break;
-	}
+	phys_shift = id_aa64mmfr0_parange_to_phys_shift(parange);
 
 	/*
 	 * ... and clamp it to 40 bits, unless we have some braindead
@@ -65,7 +47,7 @@ u32 __hyp_text __init_stage2_translation(void)
 	 * return that value for the rest of the kernel to decide what
 	 * to do.
 	 */
-	val |= 64 - (parange > 40 ? 40 : parange);
+	val |= 64 - (phys_shift > 40 ? 40 : phys_shift);
 
 	/*
 	 * Check the availability of Hardware Access Flag / Dirty Bit
@@ -86,5 +68,5 @@ u32 __hyp_text __init_stage2_translation(void)
 
 	write_sysreg(val, vtcr_el2);
 
-	return parange;
+	return phys_shift;
 }
-- 
2.13.6