From: Ard Biesheuvel <ardb@kernel.org>
To: linux-efi@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org, keescook@chromium.org,
mark.rutland@arm.com, catalin.marinas@arm.com,
Ard Biesheuvel <ardb@kernel.org>
Subject: [RFC PATCH v2 11/18] arm64: mm: make vabits_actual a build time constant if possible
Date: Wed, 30 Mar 2022 17:41:58 +0200 [thread overview]
Message-ID: <20220330154205.2483167-12-ardb@kernel.org> (raw)
In-Reply-To: <20220330154205.2483167-1-ardb@kernel.org>
Currently, we only support 52-bit virtual addressing on 64k pages
configurations, and in all other cases, vabits_actual is guaranteed to
equal VA_BITS (== VA_BITS_MIN). So get rid of the variable entirely in
that case.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/arm64/include/asm/memory.h | 4 ++++
arch/arm64/kernel/head.S | 7 +++----
arch/arm64/mm/mmu.c | 2 ++
3 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 2f1a48be11cf..c989f6bf5426 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -174,7 +174,11 @@
#include <linux/types.h>
#include <asm/bug.h>
+#if VA_BITS > 48
extern u64 vabits_actual;
+#else
+#define vabits_actual VA_BITS
+#endif
extern s64 memstart_addr;
/* PHYS_OFFSET - the physical address of the start of memory. */
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 44e2e39046a9..836237289ffb 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -283,19 +283,18 @@ SYM_FUNC_START_LOCAL(create_idmap)
adrp x0, idmap_pg_dir
adrp x3, _text // __pa(_text)
-#ifdef CONFIG_ARM64_VA_BITS_52
+#if (VA_BITS > 48)
mrs_s x6, SYS_ID_AA64MMFR2_EL1
and x6, x6, #(0xf << ID_AA64MMFR2_LVA_SHIFT)
mov x5, #52
cbnz x6, 1f
-#endif
mov x5, #VA_BITS_MIN
1:
adr_l x6, vabits_actual
str x5, [x6]
dmb sy
dc ivac, x6 // Invalidate potentially stale cache line
-
+#endif
/*
* VA_BITS may be too small to allow for an ID mapping to be created
* that covers system RAM if that is located sufficiently high in the
@@ -725,7 +724,7 @@ SYM_FUNC_START(__enable_mmu)
SYM_FUNC_END(__enable_mmu)
SYM_FUNC_START(__cpu_secondary_check52bitva)
-#ifdef CONFIG_ARM64_VA_BITS_52
+#if (VA_BITS > 48)
ldr_l x0, vabits_actual
cmp x0, #52
b.ne 2f
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 20dd95a750bc..8933d4f72427 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -45,8 +45,10 @@
u64 idmap_t0sz = TCR_T0SZ(VA_BITS_MIN);
+#if (VA_BITS > 48)
u64 __section(".mmuoff.data.write") vabits_actual;
EXPORT_SYMBOL(vabits_actual);
+#endif
u64 kimage_voffset __ro_after_init;
EXPORT_SYMBOL(kimage_voffset);
--
2.30.2
next prev parent reply other threads:[~2022-03-30 15:42 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-30 15:41 [RFC PATCH v2 00/18] arm64: efi: leave MMU and caches on at boot Ard Biesheuvel
2022-03-30 15:41 ` [RFC PATCH v2 01/18] arm64: head: drop idmap_ptrs_per_pgd Ard Biesheuvel
2022-03-30 15:41 ` [RFC PATCH v2 02/18] arm64: head: split off idmap creation code Ard Biesheuvel
2022-03-30 15:41 ` [RFC PATCH v2 03/18] arm64: kernel: drop unnecessary PoC cache clean+invalidate Ard Biesheuvel
2022-03-30 15:41 ` [RFC PATCH v2 04/18] arm64: head: cover entire kernel image in ID map Ard Biesheuvel
2022-03-30 15:41 ` [RFC PATCH v2 05/18] arm64: head: factor out TTBR1 assignment into a macro Ard Biesheuvel
2022-03-30 15:41 ` [RFC PATCH v2 06/18] arm64: head: populate kernel page tables with MMU and caches on Ard Biesheuvel
2022-03-30 15:41 ` [RFC PATCH v2 07/18] arm64: kaslr: deal with init called with VA randomization enabled Ard Biesheuvel
2022-03-30 15:41 ` [RFC PATCH v2 08/18] arm64: setup: defer R/O remapping of FDT Ard Biesheuvel
2022-03-30 15:41 ` [RFC PATCH v2 09/18] arm64: head: relocate kernel only a single time if KASLR is enabled Ard Biesheuvel
2022-03-30 15:41 ` [RFC PATCH v2 10/18] arm64: head: record the MMU state at primary entry Ard Biesheuvel
2022-03-30 15:41 ` Ard Biesheuvel [this message]
2022-03-30 15:41 ` [RFC PATCH v2 12/18] arm64: head: avoid cache invalidation when entering with the MMU on Ard Biesheuvel
2022-03-30 15:42 ` [RFC PATCH v2 13/18] arm64: head: record CPU boot mode after enabling the MMU Ard Biesheuvel
2022-03-30 15:42 ` [RFC PATCH v2 14/18] arm64: head: clean the ID map page to the PoC Ard Biesheuvel
2022-03-30 15:42 ` [RFC PATCH v2 15/18] arm64: lds: move idmap_pg_dir out of .rodata Ard Biesheuvel
2022-03-30 15:42 ` [RFC PATCH v2 16/18] efi: libstub: pass image handle to handle_kernel_image() Ard Biesheuvel
2022-03-30 15:42 ` [RFC PATCH v2 17/18] efi/arm64: libstub: run image in place if randomized by the loader Ard Biesheuvel
2022-03-30 15:42 ` [RFC PATCH v2 18/18] arm64: efi/libstub: enter with the MMU on if executing in place Ard Biesheuvel
2022-03-31 15:37 ` [RFC PATCH v2 00/18] arm64: efi: leave MMU and caches on at boot Mark Rutland
2022-03-31 16:20 ` Ard Biesheuvel
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