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From: Ard Biesheuvel <ardb@kernel.org>
To: linux-efi@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
	Ard Biesheuvel <ardb@kernel.org>,
	Russell King <linux@armlinux.org.uk>,
	Linus Walleij <linus.walleij@linaro.org>,
	Nicolas Pitre <nico@fluxnic.net>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Stefan Agner <stefan@agner.ch>, Peter Smith <Peter.Smith@arm.com>,
	Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>
Subject: [PATCH 04/12] ARM: head-common.S: use PC-relative insn sequence for __proc_info
Date: Mon, 14 Sep 2020 12:56:58 +0300	[thread overview]
Message-ID: <20200914095706.3985-5-ardb@kernel.org> (raw)
In-Reply-To: <20200914095706.3985-1-ardb@kernel.org>

Replace the open coded PC relative offset calculations with a pair of
adr_l invocations. This removes some open coded arithmetic involving
virtual addresses, avoids literal pools on v7+, and slightly reduces
the footprint of the code.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm/kernel/head-common.S | 22 ++++++--------------
 1 file changed, 6 insertions(+), 16 deletions(-)

diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index 4a3982812a40..9a5ab6c19568 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S
@@ -170,11 +170,12 @@ ENDPROC(lookup_processor_type)
  *	r9 = cpuid (preserved)
  */
 __lookup_processor_type:
-	adr	r3, __lookup_processor_type_data
-	ldmia	r3, {r4 - r6}
-	sub	r3, r3, r4			@ get offset between virt&phys
-	add	r5, r5, r3			@ convert virt addresses to
-	add	r6, r6, r3			@ physical address space
+	/*
+	 * Look in <asm/procinfo.h> for information about the __proc_info
+	 * structure.
+	 */
+	adr_l	r5, __proc_info_begin
+	adr_l	r6, __proc_info_end
 1:	ldmia	r5, {r3, r4}			@ value, mask
 	and	r4, r4, r9			@ mask wanted bits
 	teq	r3, r4
@@ -186,17 +187,6 @@ __lookup_processor_type:
 2:	ret	lr
 ENDPROC(__lookup_processor_type)
 
-/*
- * Look in <asm/procinfo.h> for information about the __proc_info structure.
- */
-	.align	2
-	.type	__lookup_processor_type_data, %object
-__lookup_processor_type_data:
-	.long	.
-	.long	__proc_info_begin
-	.long	__proc_info_end
-	.size	__lookup_processor_type_data, . - __lookup_processor_type_data
-
 __error_lpae:
 #ifdef CONFIG_DEBUG_LL
 	adr	r0, str_lpae
-- 
2.17.1


  parent reply	other threads:[~2020-09-14  9:57 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-14  9:56 [PATCH 00/12] ARM: use adr_l/ldr_l macros for PC-relative references Ard Biesheuvel
2020-09-14  9:56 ` [PATCH 01/12] ARM: assembler: introduce adr_l, ldr_l and str_l macros Ard Biesheuvel
2020-09-15  7:35   ` Ard Biesheuvel
2020-09-15 17:51     ` Nick Desaulniers
2020-09-14  9:56 ` [PATCH 02/12] ARM: efistub: replace adrl pseudo-op with adr_l macro invocation Ard Biesheuvel
2020-09-14  9:56 ` [PATCH 03/12] ARM: module: add support for place relative relocations Ard Biesheuvel
2020-09-14 13:35   ` Nicolas Pitre
2020-09-14 16:11     ` Russell King - ARM Linux admin
2020-09-14  9:56 ` Ard Biesheuvel [this message]
2020-09-14  9:56 ` [PATCH 05/12] ARM: head-common.S: use PC-relative insn sequence for idmap creation Ard Biesheuvel
2020-09-14  9:57 ` [PATCH 06/12] ARM: head.S: use PC-relative insn sequence for secondary_data Ard Biesheuvel
2020-09-14  9:57 ` [PATCH 07/12] ARM: kernel: use relative references for UP/SMP alternatives Ard Biesheuvel
2020-09-14  9:57 ` [PATCH 08/12] ARM: head: use PC-relative insn sequence for __smp_alt Ard Biesheuvel
2020-09-14  9:57 ` [PATCH 09/12] ARM: sleep.S: use PC-relative insn sequence for sleep_save_sp/mpidr_hash Ard Biesheuvel
2020-09-14  9:57 ` [PATCH 10/12] ARM: head.S: use PC-relative insn sequences for __fixup_pv_table Ard Biesheuvel
2020-09-14  9:57 ` [PATCH 11/12] ARM: head.S: use PC relative insn sequence to calculate PHYS_OFFSET Ard Biesheuvel
2020-09-14  9:57 ` [PATCH 12/12] ARM: kvm: replace open coded VA->PA calculations with adr_l call Ard Biesheuvel
2020-09-14 14:06 ` [PATCH 00/12] ARM: use adr_l/ldr_l macros for PC-relative references Nicolas Pitre
2020-09-15 19:32 ` Nick Desaulniers
2020-09-15 21:29   ` Ard Biesheuvel
2020-09-15 23:31     ` Nick Desaulniers
2020-09-16  5:54       ` Ard Biesheuvel
2020-09-16 19:53         ` Nick Desaulniers
2020-09-16 20:45           ` Ard Biesheuvel
2020-09-16 21:25             ` Nick Desaulniers
2020-09-17  0:16               ` Nick Desaulniers
2020-09-17  5:19                 ` Mike Rapoport
2020-09-17  6:01               ` Ard Biesheuvel
2020-09-18 20:03                 ` Nick Desaulniers
2020-09-18 20:44                   ` Ard Biesheuvel
2020-09-18 21:06                     ` Nick Desaulniers

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