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arm64/mm: Override PARange for !LPA2 and use it consistently

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When FEAT_LPA{,2} are not implemented, the ID_AA64MMFR0_EL1.PARange and
TCR.IPS values corresponding with 52-bit physical addressing are
reserved.

Setting the TCR.IPS field to 0b110 (52-bit physical addressing) has side
effects, such as how the TTBRn_ELx.BADDR fields are interpreted, and so
it is important that disabling FEAT_LPA2 (by overriding the
ID_AA64MMFR0.TGran fields) also presents a PARange field consistent with
that.

So limit the field to 48 bits unless LPA2 is enabled, and update
existing references to use the override consistently.

Fixes: 352b0395b5 ("arm64: Enable 52-bit virtual addressing for 4k and 16k granule configs")
Cc: stable@vger.kernel.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241212081841.2168124-10-ardb+git@google.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Ard Biesheuvel
2024-12-12 09:18:44 +01:00
committed by Will Deacon
parent bf74bb73cd
commit 62cffa496a
5 changed files with 27 additions and 2 deletions
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7
arch/arm64/mm/init.c
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@@ -279,7 +279,12 @@ void __init arm64_memblock_init(void)
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
extern u16 memstart_offset_seed;
u64 mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
/*
* Use the sanitised version of id_aa64mmfr0_el1 so that linear
* map randomization can be enabled by shrinking the IPA space.
*/
u64 mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
int parange = cpuid_feature_extract_unsigned_field(
mmfr0, ID_AA64MMFR0_EL1_PARANGE_SHIFT);
s64 range = linear_region_size -