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| author | Ard Biesheuvel <ardb@kernel.org> | 2024-12-12 09:18:44 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2024-12-19 17:23:52 +0000 |
| commit | 62cffa496aac0c2c4eeca00d080058affd7a0172 (patch) | |
| tree | 6676beda3698279c428e6f70ee4670beaec5fd90 /arch/arm64/kernel/pi | |
| parent | bf74bb73cd87c64bd5afc1fd4b749029997b6170 (diff) | |
| download | linux-62cffa496aac0c2c4eeca00d080058affd7a0172.tar.gz linux-62cffa496aac0c2c4eeca00d080058affd7a0172.tar.bz2 linux-62cffa496aac0c2c4eeca00d080058affd7a0172.zip | |
arm64/mm: Override PARange for !LPA2 and use it consistently
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: 352b0395b505 ("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>
Diffstat (limited to 'arch/arm64/kernel/pi')
| -rw-r--r-- | arch/arm64/kernel/pi/idreg-override.c | 9 | ||||
| -rw-r--r-- | arch/arm64/kernel/pi/map_kernel.c | 6 |
2 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm64/kernel/pi/idreg-override.c b/arch/arm64/kernel/pi/idreg-override.c index 22159251eb3a..c6b185b885f7 100644 --- a/arch/arm64/kernel/pi/idreg-override.c +++ b/arch/arm64/kernel/pi/idreg-override.c @@ -83,6 +83,15 @@ static bool __init mmfr2_varange_filter(u64 val) id_aa64mmfr0_override.val |= (ID_AA64MMFR0_EL1_TGRAN_LPA2 - 1) << ID_AA64MMFR0_EL1_TGRAN_SHIFT; id_aa64mmfr0_override.mask |= 0xfU << ID_AA64MMFR0_EL1_TGRAN_SHIFT; + + /* + * Override PARange to 48 bits - the override will just be + * ignored if the actual PARange is smaller, but this is + * unlikely to be the case for LPA2 capable silicon. + */ + id_aa64mmfr0_override.val |= + ID_AA64MMFR0_EL1_PARANGE_48 << ID_AA64MMFR0_EL1_PARANGE_SHIFT; + id_aa64mmfr0_override.mask |= 0xfU << ID_AA64MMFR0_EL1_PARANGE_SHIFT; } #endif return true; diff --git a/arch/arm64/kernel/pi/map_kernel.c b/arch/arm64/kernel/pi/map_kernel.c index f374a3e5a5fe..e57b043f324b 100644 --- a/arch/arm64/kernel/pi/map_kernel.c +++ b/arch/arm64/kernel/pi/map_kernel.c @@ -136,6 +136,12 @@ static void noinline __section(".idmap.text") set_ttbr0_for_lpa2(u64 ttbr) { u64 sctlr = read_sysreg(sctlr_el1); u64 tcr = read_sysreg(tcr_el1) | TCR_DS; + u64 mmfr0 = read_sysreg(id_aa64mmfr0_el1); + u64 parange = cpuid_feature_extract_unsigned_field(mmfr0, + ID_AA64MMFR0_EL1_PARANGE_SHIFT); + + tcr &= ~TCR_IPS_MASK; + tcr |= parange << TCR_IPS_SHIFT; asm(" msr sctlr_el1, %0 ;" " isb ;" |