[17/20] ARC: entry: replace 8 byte OR with 4 byte BSET

Message ID	20230815004813.555115-18-vgupta@kernel.org
State	New
Headers	show Return-Path: <linux-snps-arc-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org> From: Vineet Gupta <vgupta@kernel.org> To: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Shahab Vahedi <Shahab.Vahedi@synopsys.com>, Alexey Brodkin <abrodkin@synopsys.com>, Vineet Gupta <vgupta@kernel.org> Subject: [PATCH 17/20] ARC: entry: replace 8 byte OR with 4 byte BSET Date: Mon, 14 Aug 2023 17:48:10 -0700 Message-Id: <20230815004813.555115-18-vgupta@kernel.org> In-Reply-To: <20230815004813.555115-1-vgupta@kernel.org> References: <20230815004813.555115-1-vgupta@kernel.org> MIME-Version: 1.0 preview: FAKE_RET_FROM_EXCEPTION drops down to pure kernel mode. It currently has an 8 byte instruction which can be replaced with 4 byte BSET This is applicable to both ARCv2 and ARCv3 entr code. ARCv2 current 00000804 <EV_Trap>: ... 874: 216a 1280 lr r9,[status32] 878: 2146 1809 bic r9,r9,0x20 87c: 2105 1f89 8000 0000 or r9,r9,0x80000000 ^^^^^^^^^ 884: 2029 8240 kflag r9 Content analysis details: (-5.4 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [139.178.84.217 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.2 DKIMWL_WL_HIGH DKIMwl.org - High trust sender Precedence: list Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-snps-arc" <linux-snps-arc-bounces@lists.infradead.org> Errors-To: linux-snps-arc-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org
Series	ARC updates \| expand [00/20] ARC updates [01/20] ARC: uaccess: remove arc specific out-of-line handles for -Os [02/20] ARC: uaccess: use optimized generic __strnlen_user/__strncpy_from_user [03/20] ARC: uaccess: elide unaliged handling if hardware supports [04/20] ARCv2: memset: don't prefetch for len == 0 which happens a alot [05/20] ARC: boot log: eliminate struct cpuinfo_arc #1: mm [06/20] ARC: boot log: eliminate struct cpuinfo_arc #2: cache [07/20] ARC: boot log: eliminate struct cpuinfo_arc #3: don't export [08/20] ARC: boot log: eliminate struct cpuinfo_arc #4: boot log per ISA [09/20] ARC: entry: use gp to cache task pointer (vs. r25) [10/20] ARC: kernel stack: INIT_THREAD need not setup @init_stack in @ksp [11/20] ARC: __switch_to: asm with dwarf ops (vs. inline asm) [12/20] ARC: __switch_to: move ksp to thread_info from thread_struct [13/20] ARC: entry: rework (non-functional) [14/20] ARC: entry: ARcompact EV_ProtV to use r10 directly [15/20] ARC: entry: EV_MachineCheck dont re-read ECR [16/20] ARC: entry: Add more common chores to EXCEPTION_PROLOGUE [17/20] ARC: entry: replace 8 byte OR with 4 byte BSET [18/20] ARC: entry: replace 8 byte ADD.ne with 4 byte ADD2.ne [19/20] ARCv2: entry: rearrange pt_regs slightly [20/20] ARC: pt_regs: create seperate type for ecr

Message ID

20230815004813.555115-18-vgupta@kernel.org

State

New

Headers

From: Vineet Gupta <vgupta@kernel.org>
To: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org,
	Shahab Vahedi <Shahab.Vahedi@synopsys.com>,
	Alexey Brodkin <abrodkin@synopsys.com>,
	Vineet Gupta <vgupta@kernel.org>
Subject: [PATCH 17/20] ARC: entry: replace 8 byte OR with 4 byte BSET
Date: Mon, 14 Aug 2023 17:48:10 -0700
Message-Id: <20230815004813.555115-18-vgupta@kernel.org>
In-Reply-To: <20230815004813.555115-1-vgupta@kernel.org>
References: <20230815004813.555115-1-vgupta@kernel.org>
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Series

ARC updates | expand

Commit Message

Vineet Gupta Aug. 15, 2023, 12:48 a.m. UTC

FAKE_RET_FROM_EXCEPTION drops down to pure kernel mode. It currently has
an 8 byte instruction which can be replaced with 4 byte BSET

This is applicable to both ARCv2 and ARCv3 entr code.

ARCv2 current
------------
00000804 <EV_Trap>:
...
 874:   216a 1280               lr      r9,[status32]
 878:   2146 1809               bic     r9,r9,0x20
 87c:   2105 1f89 8000 0000     or      r9,r9,0x80000000
                  ^^^^^^^^^
 884:   2029 8240               kflag   r9

ARCv2 after
----------
000007e0 <EV_Trap>:
...
 850:   216a 1280               lr      r9,[status32]
 854:   2150 1149               bclr    r9,r9,0x5
 858:   214f 17c9               bset    r9,r9,0x1f
 85c:   2029 8240               kflag   r9

Signed-off-by: Vineet Gupta <vgupta@kernel.org>
---
 arch/arc/include/asm/entry-arcv2.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arc/include/asm/entry-arcv2.h b/arch/arc/include/asm/entry-arcv2.h
index 11b48ab39154..f7c9b3915d10 100644
--- a/arch/arc/include/asm/entry-arcv2.h
+++ b/arch/arc/include/asm/entry-arcv2.h
@@ -274,8 +274,8 @@ 
 
 .macro FAKE_RET_FROM_EXCPN
 	lr      r9, [status32]
-	bic     r9, r9, STATUS_AE_MASK
-	or      r9, r9, STATUS_IE_MASK
+	bclr    r9, r9, STATUS_AE_BIT
+	bset    r9, r9, STATUS_IE_BIT
 	kflag   r9
 .endm

[17/20] ARC: entry: replace 8 byte OR with 4 byte BSET

Commit Message

Patch