ARMv8.2 architecture hardware extensions can support upto 52-bit physical addresses (ARMv8.2-LPA) and 52-bit virtual addresses (ARMv8.2-LVA).
User-space utilities like 'makedumpfile' can try and use the getauxval() function to retrieve the underlying PARange and VARange values supported. An example implementation can be via the 'Appendix I: Example' shown in 'Documentation/arm64/cpu-feature-registers.txt'. A reference 'makedumpfile' implementation which uses a similar approach is available in [0]. So, we expose these properties via 'FTR_NONSTRICT' and 'FTR_VISIBLE' settings for 'ID_AA64MMFR0_PARANGE_SHIFT' and 'ID_AA64MMFR2_LVA_SHIFT'. [0]. https://github.com/bhupesh-sharma/makedumpfile/blob/9d7da4aad3efe79b448f48cc3454fcae46a316d6/arch/arm64.c#L499 Signed-off-by: Bhupesh Sharma <[email protected]> --- arch/arm64/kernel/cpufeature.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index f6d84e2c92fe..5cfc08cbf147 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -194,7 +194,7 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = { * Differing PARange is fine as long as all peripherals and memory are mapped * within the minimum PARange of all CPUs */ - ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0), ARM64_FTR_END, }; @@ -211,7 +211,7 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = { static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_FWB_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_AT_SHIFT, 4, 0), - ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IESB_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LSM_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_UAO_SHIFT, 4, 0), -- 2.7.4 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
