From: steve.capper@arm.com (Steve Capper)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 8/8] arm64: mm: Add 48/52-bit kernel VA support
Date: Thu, 10 May 2018 17:23:47 +0100 [thread overview]
Message-ID: <20180510162347.3858-9-steve.capper@arm.com> (raw)
In-Reply-To: <20180510162347.3858-1-steve.capper@arm.com>
Add the option to use 52-bit VA support upon availability at boot. We
use the same KASAN_SHADOW_OFFSET for both 48 and 52 bit VA spaces as in
both cases the start and end of the KASAN shadow region are PGD aligned.
>From ID_AA64MMFR2, we check the LVA field on very early boot and set the
VA size, PGDIR_SHIFT and TCR.T[01]SZ values which then influence how the
rest of the memory system behaves.
Note that userspace addresses will still be capped out at 48-bit. More
patches are needed to deal with scenarios where the user provides
MMAP_FIXED hint and a high address to mmap.
Signed-off-by: Steve Capper <steve.capper@arm.com>
---
arch/arm64/Kconfig | 10 +++++++++-
arch/arm64/mm/proc.S | 13 +++++++++++++
2 files changed, 22 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index f68eeab08904..6fe0c2976f0d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -266,6 +266,7 @@ config PGTABLE_LEVELS
default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48
+ default 3 if ARM64_64K_PAGES && 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_64K_PAGES && ARM64_VA_BITS_48
@@ -282,6 +283,7 @@ config MULTI_IRQ_HANDLER
config KASAN_SHADOW_OFFSET
hex
depends on KASAN
+ default 0xdfffa00000000000 if ARM64_VA_BITS_52
default 0xdfffa00000000000 if ARM64_VA_BITS_48
default 0xdfffd00000000000 if ARM64_VA_BITS_47
default 0xdffffe8000000000 if ARM64_VA_BITS_42
@@ -670,6 +672,10 @@ config ARM64_VA_BITS_47
config ARM64_VA_BITS_48
bool "48-bit"
+config ARM64_VA_BITS_52
+ bool "52-bit (ARMv8.2) (48 if not in hardware)"
+ depends on ARM64_64K_PAGES
+
endchoice
config ARM64_VA_BITS
@@ -679,10 +685,12 @@ config ARM64_VA_BITS
default 42 if ARM64_VA_BITS_42
default 47 if ARM64_VA_BITS_47
default 48 if ARM64_VA_BITS_48
+ default 52 if ARM64_VA_BITS_52
config ARM64_VA_BITS_MIN
int
- default ARM64_VA_BITS
+ default ARM64_VA_BITS if !ARM64_VA_BITS_52
+ default 48 if ARM64_VA_BITS_52
choice
prompt "Physical address space size"
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 5f8d9e452190..031604502776 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -472,9 +472,22 @@ ENTRY(__cpu_setup)
ENDPROC(__cpu_setup)
ENTRY(__setup_va_constants)
+#ifdef CONFIG_ARM64_VA_BITS_52
+ mrs_s x5, SYS_ID_AA64MMFR2_EL1
+ and x5, x5, #0xf << ID_AA64MMFR2_LVA_SHIFT
+ cmp x5, #1 << ID_AA64MMFR2_LVA_SHIFT
+ b.ne 1f
+ mov x0, #VA_BITS
+ mov x1, TCR_T0SZ(VA_BITS)
+ mov x2, #1 << (VA_BITS - PGDIR_SHIFT)
+ b 2f
+#endif
+
+1:
mov x0, #VA_BITS_MIN
mov x1, TCR_T0SZ(VA_BITS_MIN)
mov x2, #1 << (VA_BITS_MIN - PGDIR_SHIFT)
+2:
str_l x0, vabits_actual, x5
str_l x1, idmap_t0sz, x5
str_l x2, ptrs_per_pgd, x5
--
2.11.0
next prev parent reply other threads:[~2018-05-10 16:23 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-10 16:23 [PATCH V3 0/8] 52-bit kernel VAs for arm64 Steve Capper
2018-05-10 16:23 ` [PATCH v3 1/8] arm/arm64: KVM: Formalise end of direct linear map Steve Capper
2018-05-10 17:11 ` Marc Zyngier
2018-05-11 9:46 ` Steve Capper
2018-05-11 10:00 ` Steve Capper
2018-05-10 16:23 ` [PATCH v3 2/8] arm64: mm: Flip kernel VA space Steve Capper
2018-05-10 16:23 ` [PATCH v3 3/8] arm64: kasan: Switch to using KASAN_SHADOW_OFFSET Steve Capper
2018-05-10 16:23 ` [PATCH v3 4/8] arm64: mm: Replace fixed map BUILD_BUG_ON's with BUG_ON's Steve Capper
2018-05-10 16:23 ` [PATCH v3 5/8] arm64: dump: Make kernel page table dumper dynamic again Steve Capper
2018-05-10 16:23 ` [PATCH v3 6/8] arm64: module-plts: Extend veneer to address 52-bit VAs Steve Capper
2018-05-10 22:01 ` Ard Biesheuvel
2018-05-11 10:11 ` Steve Capper
2018-05-14 10:31 ` Ard Biesheuvel
2018-05-10 16:23 ` [PATCH v3 7/8] arm64: mm: Make VA space size variable Steve Capper
2018-05-10 16:23 ` Steve Capper [this message]
2018-09-07 6:25 ` [PATCH V3 0/8] 52-bit kernel VAs for arm64 Jon Masters
2018-09-07 14:13 ` Steve Capper
2018-09-07 19:45 ` Jon Masters
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