arm64: Check for selected granule support

Ensure that the selected page size is supported by the CPU(s). If it doesn't
park it.

Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index a7f3d4b..d59cb23 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -44,6 +44,26 @@
 #define SET_PSTATE_PAN(x) __inst_arm(0xd5000000 | REG_PSTATE_PAN_IMM |\
 				     (!!x)<<8 | 0x1f)
 
+
+#define ID_AA64MMFR0_TGRAN4_SHIFT	28
+#define ID_AA64MMFR0_TGRAN64_SHIFT	24
+#define ID_AA64MMFR0_TGRAN16_SHIFT	20
+
+#define ID_AA64MMFR0_TGRAN4_NI		0xf
+#define ID_AA64MMFR0_TGRAN4_SUPPORTED	0x0
+#define ID_AA64MMFR0_TGRAN64_NI		0xf
+#define ID_AA64MMFR0_TGRAN64_SUPPORTED	0x0
+#define ID_AA64MMFR0_TGRAN16_NI		0x0
+#define ID_AA64MMFR0_TGRAN16_SUPPORTED	0x1
+
+#if defined(CONFIG_ARM64_4K_PAGES)
+#define ID_AA64MMFR0_TGRAN_SHIFT	ID_AA64MMFR0_TGRAN4_SHIFT
+#define ID_AA64MMFR0_TGRAN_SUPPORTED	ID_AA64MMFR0_TGRAN4_SUPPORTED
+#elif defined(CONFIG_ARM64_64K_PAGES)
+#define ID_AA64MMFR0_TGRAN_SHIFT	ID_AA64MMFR0_TGRAN64_SHIFT
+#define ID_AA64MMFR0_TGRAN_SUPPORTED	ID_AA64MMFR0_TGRAN64_SUPPORTED
+#endif
+
 #ifdef __ASSEMBLY__
 
 	.irp	num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30