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arm64: Enable 52-bit virtual addressing for 4k and 16k granule configs

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Update Kconfig to permit 4k and 16k granule configurations to be built
with 52-bit virtual addressing, now that all the prerequisites are in
place.

While at it, update the feature description so it matches on the
appropriate feature bits depending on the page size. For simplicity,
let's just keep ARM64_HAS_VA52 as the feature name.

Note that LPA2 based 52-bit virtual addressing requires 52-bit physical
addressing support to be enabled as well, as programming TCR.TxSZ to
values below 16 is not allowed unless TCR.DS is set, which is what
activates the 52-bit physical addressing support.

While supporting the converse (52-bit physical addressing without 52-bit
virtual addressing) would be possible in principle, let's keep things
simple, by only allowing these features to be enabled at the same time.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240214122845.2033971-85-ardb+git@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Ard Biesheuvel 2024-02-14 13:29:26 +01:00 committed by Catalin Marinas
parent 95e059b5db
commit 352b0395b5
2 changed files with 29 additions and 12 deletions
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17
arch/arm64/Kconfig
View File

@ -368,7 +368,9 @@ config PGTABLE_LEVELS
default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
config ARCH_SUPPORTS_UPROBES
def_bool y
@ -396,13 +398,13 @@ config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
config KASAN_SHADOW_OFFSET
hex
depends on KASAN_GENERIC || KASAN_SW_TAGS
default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
@ -1310,7 +1312,7 @@ config ARM64_VA_BITS_48
config ARM64_VA_BITS_52
bool "52-bit"
depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
help
Enable 52-bit virtual addressing for userspace when explicitly
requested via a hint to mmap(). The kernel will also use 52-bit
@ -1357,10 +1359,11 @@ choice
config ARM64_PA_BITS_48
bool "48-bit"
depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
config ARM64_PA_BITS_52
bool "52-bit (ARMv8.2)"
depends on ARM64_64K_PAGES
bool "52-bit"
depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
help
Enable support for a 52-bit physical address space, introduced as

24
arch/arm64/kernel/cpufeature.c
View File

@ -2703,15 +2703,29 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
},
#ifdef CONFIG_ARM64_VA_BITS_52
{
.desc = "52-bit Virtual Addressing (LVA)",
.capability = ARM64_HAS_VA52,
.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
.sys_reg = SYS_ID_AA64MMFR2_EL1,
.sign = FTR_UNSIGNED,
.field_width = 4,
.field_pos = ID_AA64MMFR2_EL1_VARange_SHIFT,
.matches = has_cpuid_feature,
.field_width = 4,
#ifdef CONFIG_ARM64_64K_PAGES
.desc = "52-bit Virtual Addressing (LVA)",
.sign = FTR_SIGNED,
.sys_reg = SYS_ID_AA64MMFR2_EL1,
.field_pos = ID_AA64MMFR2_EL1_VARange_SHIFT,
.min_field_value = ID_AA64MMFR2_EL1_VARange_52,
#else
.desc = "52-bit Virtual Addressing (LPA2)",
.sys_reg = SYS_ID_AA64MMFR0_EL1,
#ifdef CONFIG_ARM64_4K_PAGES
.sign = FTR_SIGNED,
.field_pos = ID_AA64MMFR0_EL1_TGRAN4_SHIFT,
.min_field_value = ID_AA64MMFR0_EL1_TGRAN4_52_BIT,
#else
.sign = FTR_UNSIGNED,
.field_pos = ID_AA64MMFR0_EL1_TGRAN16_SHIFT,
.min_field_value = ID_AA64MMFR0_EL1_TGRAN16_52_BIT,
#endif
#endif
},
#endif
{},