[RFC,11/13] ARC: head: elide ZOL

Message ID	20220222141506.4003433-12-geomatsi@gmail.com
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Headers	show Return-Path: <linux-snps-arc-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org> From: Sergey Matyukevich <geomatsi@gmail.com> To: linux-snps-arc@lists.infradead.org Cc: Vineet Gupta <vgupta@kernel.org>, Vladimir Isaev <isaev@synopsys.com>, Sergey Matyukevich <geomatsi@gmail.com>, Sergey Matyukevich <sergey.matyukevich@synopsys.com> Subject: [RFC PATCH 11/13] ARC: head: elide ZOL Date: Tue, 22 Feb 2022 17:15:04 +0300 Message-Id: <20220222141506.4003433-12-geomatsi@gmail.com> In-Reply-To: <20220222141506.4003433-1-geomatsi@gmail.com> References: <20220222141506.4003433-1-geomatsi@gmail.com> MIME-Version: 1.0 preview: From: Vineet Gupta Add entry implementation based on double load/stores if ZOL is not supported. Signed-off-by: Vineet Gupta --- arch/arc/include/asm/asm-macro-ll64-emul.h \| 3 +++ arch/arc/include/asm/entry.h \| 2 ++ arch/arc/kernel/head.S \| 8 +++++++- arch/arc/kernel/vmlinux.lds.S \| 2 +- 4 file [...] Content analysis details: (-0.2 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [2a00:1450:4864:20:0:0:0:12a 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 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider [geomatsi[at]gmail.com] -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 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: handle the lack of ZOL support \| expand [RFC,00/13] ARC: handle the lack of ZOL support [RFC,01/13] ARC: uaccess: elide unaligned handling if hardware supports [RFC,02/13] ARC: Kconfig: introduce option to disable ZOL [RFC,03/13] ARC: uaccess: drop CC_OPTIMIZE_FOR_SIZE [RFC,04/13] ARC: uaccess: elide ZOL, use double load/stores [RFC,05/13] ARCv2: memset: don't prefetch for len == 0 which happens a lot [RFC,06/13] ARCv2: memset: elide unaligned handling if hardware supports [RFC,07/13] ARCv2: memset: rewrite using double load/stores [RFC,08/13] ARC: string: use generic C code if no ZOL support [RFC,09/13] ARC: delay: elide ZOL [RFC,10/13] ARC: checksum: elide ZOL [RFC,11/13] ARC: head: elide ZOL [RFC,12/13] ARC: build: inhibit ZOL generation by compiler [RFC,13/13] ARC: pt_regs: handle the case when ZOL is not supported

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20220222141506.4003433-12-geomatsi@gmail.com

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From: Sergey Matyukevich <geomatsi@gmail.com>
To: linux-snps-arc@lists.infradead.org
Cc: Vineet Gupta <vgupta@kernel.org>, Vladimir Isaev <isaev@synopsys.com>,
 Sergey Matyukevich <geomatsi@gmail.com>,
 Sergey Matyukevich <sergey.matyukevich@synopsys.com>
Subject: [RFC PATCH 11/13] ARC: head: elide ZOL
Date: Tue, 22 Feb 2022 17:15:04 +0300
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Series

ARC: handle the lack of ZOL support | expand

Commit Message

Sergey Matyukevich Feb. 22, 2022, 2:15 p.m. UTC

From: Vineet Gupta <vgupta@kernel.org>

Add entry implementation based on double load/stores
if ZOL is not supported.

Signed-off-by: Vineet Gupta <vgupta@kernel.org>
---
 arch/arc/include/asm/asm-macro-ll64-emul.h | 3 +++
 arch/arc/include/asm/entry.h               | 2 ++
 arch/arc/kernel/head.S                     | 8 +++++++-
 arch/arc/kernel/vmlinux.lds.S              | 2 +-
 4 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/arc/include/asm/asm-macro-ll64-emul.h b/arch/arc/include/asm/asm-macro-ll64-emul.h
index 886320cc74ad..417c892d557e 100644
--- a/arch/arc/include/asm/asm-macro-ll64-emul.h
+++ b/arch/arc/include/asm/asm-macro-ll64-emul.h
@@ -15,6 +15,9 @@ 
 	.ifeqs	"\d", "r6"
 		st.ab	r7, [\s, \incr / 2]
 	.endif
+	.ifeqs	"\d", "0"
+		st.ab	\d, [\s, \incr / 2]
+	.endif
 .endm
 
 .macro LD64.ab d, s, incr
diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index fcdd59d77f42..1bc9f730e1e2 100644
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -7,6 +7,8 @@ 
 #ifndef __ASM_ARC_ENTRY_H
 #define __ASM_ARC_ENTRY_H
 
+#include <asm/asm-offsets.h>
+#include <asm/assembler.h>
 #include <asm/unistd.h>		/* For NR_syscalls defination */
 #include <asm/arcregs.h>
 #include <asm/ptrace.h>
diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
index 9152782444b5..17b5426d4ca4 100644
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -121,13 +121,19 @@  ENTRY(stext)
 #endif
 
 	; Clear BSS before updating any globals
-	; XXX: use ZOL here
 	mov	r5, __bss_start
 	sub	r6, __bss_stop, r5
+#ifndef CONFIG_ARC_LACKS_ZOL
 	lsr.f	lp_count, r6, 2
 	lpnz	1f
 	st.ab   0, [r5, 4]
 1:
+#else
+	lsr	r6, r6, 3
+1:
+	ST64.ab	0, r5, 8
+	DBNZR	r6, 1b
+#endif
 
 	; Uboot - kernel ABI
 	;    r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
diff --git a/arch/arc/kernel/vmlinux.lds.S b/arch/arc/kernel/vmlinux.lds.S
index 529ae50f9fe2..00aeb89bd169 100644
--- a/arch/arc/kernel/vmlinux.lds.S
+++ b/arch/arc/kernel/vmlinux.lds.S
@@ -107,7 +107,7 @@  SECTIONS
 
 	_edata = .;
 
-	BSS_SECTION(4, 4, 4)
+	BSS_SECTION(8, 8, 8)
 
 #ifdef CONFIG_ARC_DW2_UNWIND
 	. = ALIGN(PAGE_SIZE);

[RFC,11/13] ARC: head: elide ZOL

Commit Message

Patch