linux_dsm_epyc7002/arch/mips/include/asm/mach-loongson64/kernel-entry-init.h
Huacai Chen 1e820da3c9 MIPS: Loongson-3: Introduce CONFIG_LOONGSON3_ENHANCEMENT
New Loongson 3 CPU (since Loongson-3A R2, as opposed to Loongson-3A R1,
Loongson-3B R1 and Loongson-3B R2) has many enhancements, such as FTLB,
L1-VCache, EI/DI/Wait/Prefetch instruction, DSP/DSPv2 ASE, User Local
register, Read-Inhibit/Execute-Inhibit, SFB (Store Fill Buffer), Fast
TLB refill support, etc.

This patch introduce a config option, CONFIG_LOONGSON3_ENHANCEMENT, to
enable those enhancements which are not probed at run time. If you want
a generic kernel to run on all Loongson 3 machines, please say 'N'
here. If you want a high-performance kernel to run on new Loongson 3
machines only, please say 'Y' here.

Some additional explanations:
1) SFB locates between core and L1 cache, it causes memory access out
   of order, so writel/outl (and other similar functions) need a I/O
   reorder barrier.
2) Loongson 3 has a bug that di instruction can not save the irqflag,
   so arch_local_irq_save() is modified. Since CPU_MIPSR2 is selected
   by CONFIG_LOONGSON3_ENHANCEMENT, generic kernel doesn't use ei/di
   at all.
3) CPU_HAS_PREFETCH is selected by CONFIG_LOONGSON3_ENHANCEMENT, so
   MIPS_CPU_PREFETCH (used by uasm) probing is also put in this patch.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12755/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:02:15 +02:00

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1.4 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2005 Embedded Alley Solutions, Inc
* Copyright (C) 2005 Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 2009 Jiajie Chen (chenjiajie@cse.buaa.edu.cn)
* Copyright (C) 2012 Huacai Chen (chenhc@lemote.com)
*/
#ifndef __ASM_MACH_LOONGSON64_KERNEL_ENTRY_H
#define __ASM_MACH_LOONGSON64_KERNEL_ENTRY_H
/*
* Override macros used in arch/mips/kernel/head.S.
*/
.macro kernel_entry_setup
#ifdef CONFIG_CPU_LOONGSON3
.set push
.set mips64
/* Set LPA on LOONGSON3 config3 */
mfc0 t0, $16, 3
or t0, (0x1 << 7)
mtc0 t0, $16, 3
/* Set ELPA on LOONGSON3 pagegrain */
mfc0 t0, $5, 1
or t0, (0x1 << 29)
mtc0 t0, $5, 1
#ifdef CONFIG_LOONGSON3_ENHANCEMENT
/* Enable STFill Buffer */
mfc0 t0, $16, 6
or t0, 0x100
mtc0 t0, $16, 6
#endif
_ehb
.set pop
#endif
.endm
/*
* Do SMP slave processor setup.
*/
.macro smp_slave_setup
#ifdef CONFIG_CPU_LOONGSON3
.set push
.set mips64
/* Set LPA on LOONGSON3 config3 */
mfc0 t0, $16, 3
or t0, (0x1 << 7)
mtc0 t0, $16, 3
/* Set ELPA on LOONGSON3 pagegrain */
mfc0 t0, $5, 1
or t0, (0x1 << 29)
mtc0 t0, $5, 1
#ifdef CONFIG_LOONGSON3_ENHANCEMENT
/* Enable STFill Buffer */
mfc0 t0, $16, 6
or t0, 0x100
mtc0 t0, $16, 6
#endif
_ehb
.set pop
#endif
.endm
#endif /* __ASM_MACH_LOONGSON64_KERNEL_ENTRY_H */