ARM: 9029/1: Make iwmmxt.S support Clang's integrated assembler

This patch replaces 6 IWMMXT instructions Clang's integrated assembler
does not support in iwmmxt.S using macros, while making sure GNU
assembler still emit the same instructions. This should be easier than
providing full IWMMXT support in Clang.  This is one of the last bits of
kernel code that could be compiled but not assembled with clang. Once
all of it works with IAS, we no longer need to special-case 32-bit Arm
in Kbuild, or turn off CONFIG_IWMMXT when build-testing.

"Intel Wireless MMX Technology - Developer Guide - August, 2002" should
be referenced for the encoding schemes of these extensions.

Link: https://github.com/ClangBuiltLinux/linux/issues/975

Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Jian Cai <jiancai@google.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Jian Cai 2020-11-17 23:11:36 +01:00 committed by Russell King
parent 4d576cab16
commit 3c9f5708b7
2 changed files with 92 additions and 44 deletions

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@ -16,6 +16,7 @@
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
#include <asm/assembler.h>
#include "iwmmxt.h"
#if defined(CONFIG_CPU_PJ4) || defined(CONFIG_CPU_PJ4B)
#define PJ4(code...) code
@ -113,33 +114,33 @@ concan_save:
concan_dump:
wstrw wCSSF, [r1, #MMX_WCSSF]
wstrw wCASF, [r1, #MMX_WCASF]
wstrw wCGR0, [r1, #MMX_WCGR0]
wstrw wCGR1, [r1, #MMX_WCGR1]
wstrw wCGR2, [r1, #MMX_WCGR2]
wstrw wCGR3, [r1, #MMX_WCGR3]
wstrw wCSSF, r1, MMX_WCSSF
wstrw wCASF, r1, MMX_WCASF
wstrw wCGR0, r1, MMX_WCGR0
wstrw wCGR1, r1, MMX_WCGR1
wstrw wCGR2, r1, MMX_WCGR2
wstrw wCGR3, r1, MMX_WCGR3
1: @ MUP? wRn
tst r2, #0x2
beq 2f
wstrd wR0, [r1, #MMX_WR0]
wstrd wR1, [r1, #MMX_WR1]
wstrd wR2, [r1, #MMX_WR2]
wstrd wR3, [r1, #MMX_WR3]
wstrd wR4, [r1, #MMX_WR4]
wstrd wR5, [r1, #MMX_WR5]
wstrd wR6, [r1, #MMX_WR6]
wstrd wR7, [r1, #MMX_WR7]
wstrd wR8, [r1, #MMX_WR8]
wstrd wR9, [r1, #MMX_WR9]
wstrd wR10, [r1, #MMX_WR10]
wstrd wR11, [r1, #MMX_WR11]
wstrd wR12, [r1, #MMX_WR12]
wstrd wR13, [r1, #MMX_WR13]
wstrd wR14, [r1, #MMX_WR14]
wstrd wR15, [r1, #MMX_WR15]
wstrd wR0, r1, MMX_WR0
wstrd wR1, r1, MMX_WR1
wstrd wR2, r1, MMX_WR2
wstrd wR3, r1, MMX_WR3
wstrd wR4, r1, MMX_WR4
wstrd wR5, r1, MMX_WR5
wstrd wR6, r1, MMX_WR6
wstrd wR7, r1, MMX_WR7
wstrd wR8, r1, MMX_WR8
wstrd wR9, r1, MMX_WR9
wstrd wR10, r1, MMX_WR10
wstrd wR11, r1, MMX_WR11
wstrd wR12, r1, MMX_WR12
wstrd wR13, r1, MMX_WR13
wstrd wR14, r1, MMX_WR14
wstrd wR15, r1, MMX_WR15
2: teq r0, #0 @ anything to load?
reteq lr @ if not, return
@ -147,30 +148,30 @@ concan_dump:
concan_load:
@ Load wRn
wldrd wR0, [r0, #MMX_WR0]
wldrd wR1, [r0, #MMX_WR1]
wldrd wR2, [r0, #MMX_WR2]
wldrd wR3, [r0, #MMX_WR3]
wldrd wR4, [r0, #MMX_WR4]
wldrd wR5, [r0, #MMX_WR5]
wldrd wR6, [r0, #MMX_WR6]
wldrd wR7, [r0, #MMX_WR7]
wldrd wR8, [r0, #MMX_WR8]
wldrd wR9, [r0, #MMX_WR9]
wldrd wR10, [r0, #MMX_WR10]
wldrd wR11, [r0, #MMX_WR11]
wldrd wR12, [r0, #MMX_WR12]
wldrd wR13, [r0, #MMX_WR13]
wldrd wR14, [r0, #MMX_WR14]
wldrd wR15, [r0, #MMX_WR15]
wldrd wR0, r0, MMX_WR0
wldrd wR1, r0, MMX_WR1
wldrd wR2, r0, MMX_WR2
wldrd wR3, r0, MMX_WR3
wldrd wR4, r0, MMX_WR4
wldrd wR5, r0, MMX_WR5
wldrd wR6, r0, MMX_WR6
wldrd wR7, r0, MMX_WR7
wldrd wR8, r0, MMX_WR8
wldrd wR9, r0, MMX_WR9
wldrd wR10, r0, MMX_WR10
wldrd wR11, r0, MMX_WR11
wldrd wR12, r0, MMX_WR12
wldrd wR13, r0, MMX_WR13
wldrd wR14, r0, MMX_WR14
wldrd wR15, r0, MMX_WR15
@ Load wCx
wldrw wCSSF, [r0, #MMX_WCSSF]
wldrw wCASF, [r0, #MMX_WCASF]
wldrw wCGR0, [r0, #MMX_WCGR0]
wldrw wCGR1, [r0, #MMX_WCGR1]
wldrw wCGR2, [r0, #MMX_WCGR2]
wldrw wCGR3, [r0, #MMX_WCGR3]
wldrw wCSSF, r0, MMX_WCSSF
wldrw wCASF, r0, MMX_WCASF
wldrw wCGR0, r0, MMX_WCGR0
wldrw wCGR1, r0, MMX_WCGR1
wldrw wCGR2, r0, MMX_WCGR2
wldrw wCGR3, r0, MMX_WCGR3
@ clear CUP/MUP (only if r1 != 0)
teq r1, #0

47
arch/arm/kernel/iwmmxt.h Normal file
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@ -0,0 +1,47 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __IWMMXT_H__
#define __IWMMXT_H__
.irp b, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
.set .LwR\b, \b
.set .Lr\b, \b
.endr
.set .LwCSSF, 0x2
.set .LwCASF, 0x3
.set .LwCGR0, 0x8
.set .LwCGR1, 0x9
.set .LwCGR2, 0xa
.set .LwCGR3, 0xb
.macro wldrd, reg:req, base:req, offset:req
.inst 0xedd00100 | (.L\reg << 12) | (.L\base << 16) | (\offset >> 2)
.endm
.macro wldrw, reg:req, base:req, offset:req
.inst 0xfd900100 | (.L\reg << 12) | (.L\base << 16) | (\offset >> 2)
.endm
.macro wstrd, reg:req, base:req, offset:req
.inst 0xedc00100 | (.L\reg << 12) | (.L\base << 16) | (\offset >> 2)
.endm
.macro wstrw, reg:req, base:req, offset:req
.inst 0xfd800100 | (.L\reg << 12) | (.L\base << 16) | (\offset >> 2)
.endm
#ifdef __clang__
#define wCon c1
.macro tmrc, dest:req, control:req
mrc p1, 0, \dest, \control, c0, 0
.endm
.macro tmcr, control:req, src:req
mcr p1, 0, \src, \control, c0, 0
.endm
#endif
#endif