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From: Ard Biesheuvel <ardb@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-hardening@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
	Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Kees Cook <keescook@chromium.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Mark Brown <broonie@kernel.org>,
	Anshuman Khandual <anshuman.khandual@arm.com>
Subject: [PATCH v4 16/26] arm64: head: factor out TTBR1 assignment into a macro
Date: Mon, 13 Jun 2022 16:45:40 +0200	[thread overview]
Message-ID: <20220613144550.3760857-17-ardb@kernel.org> (raw)
In-Reply-To: <20220613144550.3760857-1-ardb@kernel.org>

Create a macro load_ttbr1 to avoid having to repeat the same instruction
sequence 3 times in a subsequent patch. No functional change intended.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm64/include/asm/assembler.h | 17 +++++++++++++----
 arch/arm64/kernel/head.S           |  5 +----
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 9468f45c07a6..b2584709c332 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -479,6 +479,18 @@ alternative_endif
 	_cond_extable .Licache_op\@, \fixup
 	.endm
 
+/*
+ * load_ttbr1 - install @pgtbl as a TTBR1 page table
+ * pgtbl preserved
+ * tmp1/tmp2 clobbered, either may overlap with pgtbl
+ */
+	.macro		load_ttbr1, pgtbl, tmp1, tmp2
+	phys_to_ttbr	\tmp1, \pgtbl
+	offset_ttbr1 	\tmp1, \tmp2
+	msr		ttbr1_el1, \tmp1
+	isb
+	.endm
+
 /*
  * To prevent the possibility of old and new partial table walks being visible
  * in the tlb, switch the ttbr to a zero page when we invalidate the old
@@ -492,10 +504,7 @@ alternative_endif
 	isb
 	tlbi	vmalle1
 	dsb	nsh
-	phys_to_ttbr \tmp, \page_table
-	offset_ttbr1 \tmp, \tmp2
-	msr	ttbr1_el1, \tmp
-	isb
+	load_ttbr1 \page_table, \tmp, \tmp2
 	.endm
 
 /*
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 64ebff634b83..d704d0bd8ffc 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -722,12 +722,9 @@ SYM_FUNC_START(__enable_mmu)
 	cmp     x3, #ID_AA64MMFR0_TGRAN_SUPPORTED_MAX
 	b.gt    __no_granule_support
 	update_early_cpu_boot_status 0, x3, x4
-	phys_to_ttbr x1, x1
 	phys_to_ttbr x2, x2
 	msr	ttbr0_el1, x2			// load TTBR0
-	offset_ttbr1 x1, x3
-	msr	ttbr1_el1, x1			// load TTBR1
-	isb
+	load_ttbr1 x1, x1, x3
 
 	set_sctlr_el1	x0
 
-- 
2.30.2


  parent reply	other threads:[~2022-06-13 18:31 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-13 14:45 [PATCH v4 00/26] arm64: refactor boot flow and add support for WXN Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 01/26] arm64: head: move kimage_vaddr variable into C file Ard Biesheuvel
2022-06-14  8:26   ` Anshuman Khandual
2022-06-13 14:45 ` [PATCH v4 02/26] arm64: mm: make vabits_actual a build time constant if possible Ard Biesheuvel
2022-06-14  8:25   ` Anshuman Khandual
2022-06-14  8:34     ` Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 03/26] arm64: head: move assignment of idmap_t0sz to C code Ard Biesheuvel
2022-06-14  9:22   ` Anshuman Khandual
2022-06-14  9:34     ` Ard Biesheuvel
2022-06-24 12:36   ` Will Deacon
2022-06-24 12:57     ` Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 04/26] arm64: head: drop idmap_ptrs_per_pgd Ard Biesheuvel
2022-06-15  4:07   ` Anshuman Khandual
2022-06-13 14:45 ` [PATCH v4 05/26] arm64: head: simplify page table mapping macros (slightly) Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 06/26] arm64: head: switch to map_memory macro for the extended ID map Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 07/26] arm64: head: split off idmap creation code Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 08/26] arm64: kernel: drop unnecessary PoC cache clean+invalidate Ard Biesheuvel
2022-06-15  4:32   ` Anshuman Khandual
2022-06-13 14:45 ` [PATCH v4 09/26] arm64: head: pass ID map root table address to __enable_mmu() Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 10/26] arm64: mm: provide idmap pointer to cpu_replace_ttbr1() Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 11/26] arm64: head: add helper function to remap regions in early page tables Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 12/26] arm64: head: cover entire kernel image in initial ID map Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 13/26] arm64: head: use relative references to the RELA and RELR tables Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 14/26] arm64: head: create a temporary FDT mapping in the initial ID map Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 15/26] arm64: idreg-override: use early FDT mapping in " Ard Biesheuvel
2022-06-13 14:45 ` Ard Biesheuvel [this message]
2022-06-13 14:45 ` [PATCH v4 17/26] arm64: head: populate kernel page tables with MMU and caches on Ard Biesheuvel
2022-06-24 12:56   ` Will Deacon
2022-06-24 13:07     ` Ard Biesheuvel
2022-06-24 13:29       ` Will Deacon
2022-06-24 14:07         ` Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 18/26] arm64: head: record CPU boot mode after enabling the MMU Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 19/26] arm64: kaslr: defer initialization to late initcall where permitted Ard Biesheuvel
2022-06-24 13:08   ` Will Deacon
2022-06-24 13:09     ` Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 20/26] arm64: head: avoid relocating the kernel twice for KASLR Ard Biesheuvel
2022-06-24 13:16   ` Will Deacon
2022-06-24 13:17     ` Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 21/26] arm64: setup: drop early FDT pointer helpers Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 22/26] arm64: mm: move ro_after_init section into the data segment Ard Biesheuvel
2022-06-13 17:00   ` Kees Cook
2022-06-13 17:16     ` Ard Biesheuvel
2022-06-13 23:38       ` Kees Cook
2022-06-16 11:31         ` Ard Biesheuvel
2022-06-16 16:18           ` Kees Cook
2022-06-16 16:31             ` Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 23/26] arm64: head: remap the kernel text/inittext region read-only Ard Biesheuvel
2022-06-13 16:57   ` Kees Cook
2022-06-13 14:45 ` [PATCH v4 24/26] mm: add arch hook to validate mmap() prot flags Ard Biesheuvel
2022-06-13 16:37   ` Kees Cook
2022-06-13 16:44     ` Ard Biesheuvel
2022-06-13 14:45 ` [PATCH v4 25/26] arm64: mm: add support for WXN memory translation attribute Ard Biesheuvel
2022-06-13 16:51   ` Kees Cook
2022-06-13 14:45 ` [PATCH v4 26/26] arm64: kernel: move ID map out of .text mapping Ard Biesheuvel
2022-06-13 16:52   ` Kees Cook
2022-06-24 13:19 ` [PATCH v4 00/26] arm64: refactor boot flow and add support for WXN Will Deacon
2022-06-24 14:40   ` Ard Biesheuvel

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