Nobody is maintaining SMTC anymore and there also seems to be no userbase. Which is a pity - the SMTC technology primarily developed by Kevin D. Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT ASE's power and elegance. Based on Markos Chandras <Markos.Chandras@imgtec.com> patch https://patchwork.linux-mips.org/patch/6719/ which while very similar did no longer apply cleanly when I tried to merge it plus some additional post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to merge once upon a time. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
		
			
				
	
	
		
			161 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			161 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * This file is subject to the terms and conditions of the GNU General Public
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 * License.  See the file "COPYING" in the main directory of this archive
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 * for more details.
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 *
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 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003 by Ralf Baechle
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 * Copyright (C) 1996 by Paul M. Antoine
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 * Copyright (C) 1999 Silicon Graphics
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 * Copyright (C) 2000 MIPS Technologies, Inc.
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 */
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#include <asm/irqflags.h>
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#include <asm/hazards.h>
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#include <linux/compiler.h>
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#include <linux/preempt.h>
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#include <linux/export.h>
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#include <linux/stringify.h>
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#ifndef CONFIG_CPU_MIPSR2
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/*
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 * For cli() we have to insert nops to make sure that the new value
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 * has actually arrived in the status register before the end of this
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 * macro.
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 * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs
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 * no nops at all.
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 */
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/*
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 * For TX49, operating only IE bit is not enough.
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 *
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 * If mfc0 $12 follows store and the mfc0 is last instruction of a
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 * page and fetching the next instruction causes TLB miss, the result
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 * of the mfc0 might wrongly contain EXL bit.
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 *
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 * ERT-TX49H2-027, ERT-TX49H3-012, ERT-TX49HL3-006, ERT-TX49H4-008
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 *
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 * Workaround: mask EXL bit of the result or place a nop before mfc0.
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 */
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notrace void arch_local_irq_disable(void)
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{
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	preempt_disable();
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	__asm__ __volatile__(
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	"	.set	push						\n"
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	"	.set	noat						\n"
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#if   defined(CONFIG_CPU_MIPSR2)
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	/* see irqflags.h for inline function */
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#else
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	"	mfc0	$1,$12						\n"
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	"	ori	$1,0x1f						\n"
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	"	xori	$1,0x1f						\n"
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	"	.set	noreorder					\n"
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	"	mtc0	$1,$12						\n"
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#endif
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	"	" __stringify(__irq_disable_hazard) "			\n"
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	"	.set	pop						\n"
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	: /* no outputs */
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	: /* no inputs */
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	: "memory");
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	preempt_enable();
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}
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EXPORT_SYMBOL(arch_local_irq_disable);
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notrace unsigned long arch_local_irq_save(void)
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{
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	unsigned long flags;
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	preempt_disable();
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	__asm__ __volatile__(
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	"	.set	push						\n"
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	"	.set	reorder						\n"
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	"	.set	noat						\n"
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#if   defined(CONFIG_CPU_MIPSR2)
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	/* see irqflags.h for inline function */
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#else
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	"	mfc0	%[flags], $12					\n"
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	"	ori	$1, %[flags], 0x1f				\n"
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	"	xori	$1, 0x1f					\n"
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	"	.set	noreorder					\n"
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	"	mtc0	$1, $12						\n"
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#endif
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	"	" __stringify(__irq_disable_hazard) "			\n"
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	"	.set	pop						\n"
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	: [flags] "=r" (flags)
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	: /* no inputs */
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	: "memory");
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	preempt_enable();
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	return flags;
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}
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EXPORT_SYMBOL(arch_local_irq_save);
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notrace void arch_local_irq_restore(unsigned long flags)
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{
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	unsigned long __tmp1;
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	preempt_disable();
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	__asm__ __volatile__(
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	"	.set	push						\n"
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	"	.set	noreorder					\n"
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	"	.set	noat						\n"
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#if   defined(CONFIG_CPU_MIPSR2) && defined(CONFIG_IRQ_CPU)
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	/* see irqflags.h for inline function */
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#elif defined(CONFIG_CPU_MIPSR2)
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	/* see irqflags.h for inline function */
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#else
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	"	mfc0	$1, $12						\n"
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	"	andi	%[flags], 1					\n"
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	"	ori	$1, 0x1f					\n"
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	"	xori	$1, 0x1f					\n"
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	"	or	%[flags], $1					\n"
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	"	mtc0	%[flags], $12					\n"
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#endif
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	"	" __stringify(__irq_disable_hazard) "			\n"
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	"	.set	pop						\n"
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	: [flags] "=r" (__tmp1)
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	: "0" (flags)
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	: "memory");
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	preempt_enable();
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}
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EXPORT_SYMBOL(arch_local_irq_restore);
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notrace void __arch_local_irq_restore(unsigned long flags)
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{
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	unsigned long __tmp1;
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	preempt_disable();
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	__asm__ __volatile__(
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	"	.set	push						\n"
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	"	.set	noreorder					\n"
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	"	.set	noat						\n"
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#if   defined(CONFIG_CPU_MIPSR2) && defined(CONFIG_IRQ_CPU)
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	/* see irqflags.h for inline function */
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#elif defined(CONFIG_CPU_MIPSR2)
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	/* see irqflags.h for inline function */
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#else
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	"	mfc0	$1, $12						\n"
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	"	andi	%[flags], 1					\n"
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	"	ori	$1, 0x1f					\n"
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	"	xori	$1, 0x1f					\n"
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	"	or	%[flags], $1					\n"
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	"	mtc0	%[flags], $12					\n"
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#endif
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	"	" __stringify(__irq_disable_hazard) "			\n"
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	"	.set	pop						\n"
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	: [flags] "=r" (__tmp1)
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	: "0" (flags)
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	: "memory");
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	preempt_enable();
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}
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EXPORT_SYMBOL(__arch_local_irq_restore);
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#endif /* !CONFIG_CPU_MIPSR2 */
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