Commit 5793e273 authored by Vineet Gupta's avatar Vineet Gupta
Browse files

ARC: intc: split into ARCompact ISA specific, common bits 



Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent 6ffb9c8c

arch/arc/include/asm/entry-compact.h

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Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#define __ASM_ARC_ENTRY_COMPACT_H



#include <asm/asm-offsets.h>

#include <asm/irqflags-compact.h>

#include <asm/thread_info.h>	/* For THREAD_SIZE */



/*--------------------------------------------------------------

arch/arc/include/asm/irqflags-compact.h

0 → 100644
+181 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)

 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */



#ifndef __ASM_IRQFLAGS_ARCOMPACT_H

#define __ASM_IRQFLAGS_ARCOMPACT_H



/* vineetg: March 2010 : local_irq_save( ) optimisation

 *  -Remove explicit mov of current status32 into reg, that is not needed

 *  -Use BIC  insn instead of INVERTED + AND

 *  -Conditionally disable interrupts (if they are not enabled, don't disable)

*/



#include <asm/arcregs.h>



/* status32 Reg bits related to Interrupt Handling */

#define STATUS_E1_BIT		1	/* Int 1 enable */

#define STATUS_E2_BIT		2	/* Int 2 enable */

#define STATUS_A1_BIT		3	/* Int 1 active */

#define STATUS_A2_BIT		4	/* Int 2 active */



#define STATUS_E1_MASK		(1<<STATUS_E1_BIT)

#define STATUS_E2_MASK		(1<<STATUS_E2_BIT)

#define STATUS_A1_MASK		(1<<STATUS_A1_BIT)

#define STATUS_A2_MASK		(1<<STATUS_A2_BIT)

#define STATUS_IE_MASK		(STATUS_E1_MASK | STATUS_E2_MASK)



/* Other Interrupt Handling related Aux regs */

#define AUX_IRQ_LEV		0x200	/* IRQ Priority: L1 or L2 */

#define AUX_IRQ_HINT		0x201	/* For generating Soft Interrupts */

#define AUX_IRQ_LV12		0x43	/* interrupt level register */



#define AUX_IENABLE		0x40c

#define AUX_ITRIGGER		0x40d

#define AUX_IPULSE		0x415



#ifndef __ASSEMBLY__



/******************************************************************

 * IRQ Control Macros

 *

 * All of them have "memory" clobber (compiler barrier) which is needed to

 * ensure that LD/ST requiring irq safetly (R-M-W when LLSC is not available)

 * are redone after IRQs are re-enabled (and gcc doesn't reuse stale register)

 *

 * Noted at the time of Abilis Timer List corruption

 *	Orig Bug + Rejected solution	: https://lkml.org/lkml/2013/3/29/67

 *	Reasoning			: https://lkml.org/lkml/2013/4/8/15

 *

 ******************************************************************/



/*

 * Save IRQ state and disable IRQs

 */

static inline long arch_local_irq_save(void)

{

	unsigned long temp, flags;



	__asm__ __volatile__(

	"	lr  %1, [status32]	\n"

	"	bic %0, %1, %2		\n"

	"	and.f 0, %1, %2	\n"

	"	flag.nz %0		\n"

	: "=r"(temp), "=r"(flags)

	: "n"((STATUS_E1_MASK | STATUS_E2_MASK))

	: "memory", "cc");



	return flags;

}



/*

 * restore saved IRQ state

 */

static inline void arch_local_irq_restore(unsigned long flags)

{



	__asm__ __volatile__(

	"	flag %0			\n"

	:

	: "r"(flags)

	: "memory");

}



/*

 * Unconditionally Enable IRQs

 */

extern void arch_local_irq_enable(void);



/*

 * Unconditionally Disable IRQs

 */

static inline void arch_local_irq_disable(void)

{

	unsigned long temp;



	__asm__ __volatile__(

	"	lr  %0, [status32]	\n"

	"	and %0, %0, %1		\n"

	"	flag %0			\n"

	: "=&r"(temp)

	: "n"(~(STATUS_E1_MASK | STATUS_E2_MASK))

	: "memory");

}



/*

 * save IRQ state

 */

static inline long arch_local_save_flags(void)

{

	unsigned long temp;



	__asm__ __volatile__(

	"	lr  %0, [status32]	\n"

	: "=&r"(temp)

	:

	: "memory");



	return temp;

}



/*

 * Query IRQ state

 */

static inline int arch_irqs_disabled_flags(unsigned long flags)

{

	return !(flags & (STATUS_E1_MASK

#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS

			| STATUS_E2_MASK

#endif

		));

}



static inline int arch_irqs_disabled(void)

{

	return arch_irqs_disabled_flags(arch_local_save_flags());

}



#else



#ifdef CONFIG_TRACE_IRQFLAGS



.macro TRACE_ASM_IRQ_DISABLE

	bl	trace_hardirqs_off

.endm



.macro TRACE_ASM_IRQ_ENABLE

	bl	trace_hardirqs_on

.endm



#else



.macro TRACE_ASM_IRQ_DISABLE

.endm



.macro TRACE_ASM_IRQ_ENABLE

.endm



#endif



.macro IRQ_DISABLE  scratch

	lr	\scratch, [status32]

	bic	\scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)

	flag	\scratch

	TRACE_ASM_IRQ_DISABLE

.endm



.macro IRQ_ENABLE  scratch

	lr	\scratch, [status32]

	or	\scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)

	flag	\scratch

	TRACE_ASM_IRQ_ENABLE

.endm



#endif	/* __ASSEMBLY__ */



#endif

arch/arc/include/asm/irqflags.h

+2 −166
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)

 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)

 *

 * This program is free software; you can redistribute it and/or modify
@@ -9,171 +10,6 @@ 
#ifndef __ASM_ARC_IRQFLAGS_H

#define __ASM_ARC_IRQFLAGS_H



/* vineetg: March 2010 : local_irq_save( ) optimisation

 *  -Remove explicit mov of current status32 into reg, that is not needed

 *  -Use BIC  insn instead of INVERTED + AND

 *  -Conditionally disable interrupts (if they are not enabled, don't disable)

*/



#include <asm/arcregs.h>



/* status32 Reg bits related to Interrupt Handling */

#define STATUS_E1_BIT		1	/* Int 1 enable */

#define STATUS_E2_BIT		2	/* Int 2 enable */

#define STATUS_A1_BIT		3	/* Int 1 active */

#define STATUS_A2_BIT		4	/* Int 2 active */



#define STATUS_E1_MASK		(1<<STATUS_E1_BIT)

#define STATUS_E2_MASK		(1<<STATUS_E2_BIT)

#define STATUS_A1_MASK		(1<<STATUS_A1_BIT)

#define STATUS_A2_MASK		(1<<STATUS_A2_BIT)



/* Other Interrupt Handling related Aux regs */

#define AUX_IRQ_LEV		0x200	/* IRQ Priority: L1 or L2 */

#define AUX_IRQ_HINT		0x201	/* For generating Soft Interrupts */

#define AUX_IRQ_LV12		0x43	/* interrupt level register */



#define AUX_IENABLE		0x40c

#define AUX_ITRIGGER		0x40d

#define AUX_IPULSE		0x415



#ifndef __ASSEMBLY__



/******************************************************************

 * IRQ Control Macros

 *

 * All of them have "memory" clobber (compiler barrier) which is needed to

 * ensure that LD/ST requiring irq safetly (R-M-W when LLSC is not available)

 * are redone after IRQs are re-enabled (and gcc doesn't reuse stale register)

 *

 * Noted at the time of Abilis Timer List corruption

 * 	Orig Bug + Rejected solution	: https://lkml.org/lkml/2013/3/29/67

 * 	Reasoning			: https://lkml.org/lkml/2013/4/8/15

 *

 ******************************************************************/



/*

 * Save IRQ state and disable IRQs

 */

static inline long arch_local_irq_save(void)

{

	unsigned long temp, flags;



	__asm__ __volatile__(

	"	lr  %1, [status32]	\n"

	"	bic %0, %1, %2		\n"

	"	and.f 0, %1, %2	\n"

	"	flag.nz %0		\n"

	: "=r"(temp), "=r"(flags)

	: "n"((STATUS_E1_MASK | STATUS_E2_MASK))

	: "memory", "cc");



	return flags;

}



/*

 * restore saved IRQ state

 */

static inline void arch_local_irq_restore(unsigned long flags)

{



	__asm__ __volatile__(

	"	flag %0			\n"

	:

	: "r"(flags)

	: "memory");

}



/*

 * Unconditionally Enable IRQs

 */

extern void arch_local_irq_enable(void);



/*

 * Unconditionally Disable IRQs

 */

static inline void arch_local_irq_disable(void)

{

	unsigned long temp;



	__asm__ __volatile__(

	"	lr  %0, [status32]	\n"

	"	and %0, %0, %1		\n"

	"	flag %0			\n"

	: "=&r"(temp)

	: "n"(~(STATUS_E1_MASK | STATUS_E2_MASK))

	: "memory");

}



/*

 * save IRQ state

 */

static inline long arch_local_save_flags(void)

{

	unsigned long temp;



	__asm__ __volatile__(

	"	lr  %0, [status32]	\n"

	: "=&r"(temp)

	:

	: "memory");



	return temp;

}



/*

 * Query IRQ state

 */

static inline int arch_irqs_disabled_flags(unsigned long flags)

{

	return !(flags & (STATUS_E1_MASK

#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS

			| STATUS_E2_MASK

#endif

		));

}



static inline int arch_irqs_disabled(void)

{

	return arch_irqs_disabled_flags(arch_local_save_flags());

}



#else



#ifdef CONFIG_TRACE_IRQFLAGS



.macro TRACE_ASM_IRQ_DISABLE

	bl	trace_hardirqs_off

.endm



.macro TRACE_ASM_IRQ_ENABLE

	bl	trace_hardirqs_on

.endm



#else



.macro TRACE_ASM_IRQ_DISABLE

.endm



.macro TRACE_ASM_IRQ_ENABLE

.endm



#endif



.macro IRQ_DISABLE  scratch

	lr	\scratch, [status32]

	bic	\scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)

	flag	\scratch

	TRACE_ASM_IRQ_DISABLE

.endm



.macro IRQ_ENABLE  scratch

	lr	\scratch, [status32]

	or	\scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)

	flag	\scratch

	TRACE_ASM_IRQ_ENABLE

.endm



#endif	/* __ASSEMBLY__ */

#include <asm/irqflags-compact.h>



#endif

arch/arc/kernel/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -10,7 +10,7 @@ CFLAGS_ptrace.o += -DUTS_MACHINE='"$(UTS_MACHINE)"' 


obj-y	:= arcksyms.o setup.o irq.o time.o reset.o ptrace.o process.o devtree.o

obj-y	+= signal.o traps.o sys.o troubleshoot.o stacktrace.o disasm.o clk.o

obj-y	+= entry-compact.o

obj-y	+= entry-compact.o intc-compact.o



obj-$(CONFIG_MODULES)			+= arcksyms.o module.o

obj-$(CONFIG_SMP) 			+= smp.o

arch/arc/kernel/intc-compact.c

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/*

 * Copyright (C) 2011-12 Synopsys, Inc. (www.synopsys.com)

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 */



#include <linux/interrupt.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/irqdomain.h>

#include <linux/irqchip.h>

#include "../../drivers/irqchip/irqchip.h"

#include <asm/irq.h>



/*

 * Early Hardware specific Interrupt setup

 * -Platform independent, needed for each CPU (not foldable into init_IRQ)

 * -Called very early (start_kernel -> setup_arch -> setup_processor)

 *

 * what it does ?

 * -Optionally, setup the High priority Interrupts as Level 2 IRQs

 */

void arc_init_IRQ(void)

{

	int level_mask = 0;



       /* setup any high priority Interrupts (Level2 in ARCompact jargon) */

	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ3_LV2) << 3;

	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ5_LV2) << 5;

	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ6_LV2) << 6;



	/*

	 * Write to register, even if no LV2 IRQs configured to reset it

	 * in case bootloader had mucked with it

	 */

	write_aux_reg(AUX_IRQ_LEV, level_mask);



	if (level_mask)

		pr_info("Level-2 interrupts bitset %x\n", level_mask);

}



/*

 * ARC700 core includes a simple on-chip intc supporting

 * -per IRQ enable/disable

 * -2 levels of interrupts (high/low)

 * -all interrupts being level triggered

 *

 * To reduce platform code, we assume all IRQs directly hooked-up into intc.

 * Platforms with external intc, hence cascaded IRQs, are free to over-ride

 * below, per IRQ.

 */



static void arc_irq_mask(struct irq_data *data)

{

	unsigned int ienb;



	ienb = read_aux_reg(AUX_IENABLE);

	ienb &= ~(1 << data->irq);

	write_aux_reg(AUX_IENABLE, ienb);

}



static void arc_irq_unmask(struct irq_data *data)

{

	unsigned int ienb;



	ienb = read_aux_reg(AUX_IENABLE);

	ienb |= (1 << data->irq);

	write_aux_reg(AUX_IENABLE, ienb);

}



static struct irq_chip onchip_intc = {

	.name           = "ARC In-core Intc",

	.irq_mask	= arc_irq_mask,

	.irq_unmask	= arc_irq_unmask,

};



static int arc_intc_domain_map(struct irq_domain *d, unsigned int irq,

			       irq_hw_number_t hw)

{

	/*

	 * XXX: the IPI IRQ needs to be handled like TIMER too. However ARC core

	 *      code doesn't own it (like TIMER0). ISS IDU / ezchip define it

	 *      in platform header which can't be included here as it goes

	 *      against multi-platform image philisophy

	 */

	if (irq == TIMER0_IRQ)

		irq_set_chip_and_handler(irq, &onchip_intc, handle_percpu_irq);

	else

		irq_set_chip_and_handler(irq, &onchip_intc, handle_level_irq);



	return 0;

}



static const struct irq_domain_ops arc_intc_domain_ops = {

	.xlate = irq_domain_xlate_onecell,

	.map = arc_intc_domain_map,

};



static struct irq_domain *root_domain;



static int __init

init_onchip_IRQ(struct device_node *intc, struct device_node *parent)

{

	if (parent)

		panic("DeviceTree incore intc not a root irq controller\n");



	root_domain = irq_domain_add_legacy(intc, NR_CPU_IRQS, 0, 0,

					    &arc_intc_domain_ops, NULL);



	if (!root_domain)

		panic("root irq domain not avail\n");



	/* with this we don't need to export root_domain */

	irq_set_default_host(root_domain);



	return 0;

}



IRQCHIP_DECLARE(arc_intc, "snps,arc700-intc", init_onchip_IRQ);



/*

 * arch_local_irq_enable - Enable interrupts.

 *

 * 1. Explicitly called to re-enable interrupts

 * 2. Implicitly called from spin_unlock_irq, write_unlock_irq etc

 *    which maybe in hard ISR itself

 *

 * Semantics of this function change depending on where it is called from:

 *

 * -If called from hard-ISR, it must not invert interrupt priorities

 *  e.g. suppose TIMER is high priority (Level 2) IRQ

 *    Time hard-ISR, timer_interrupt( ) calls spin_unlock_irq several times.

 *    Here local_irq_enable( ) shd not re-enable lower priority interrupts

 * -If called from soft-ISR, it must re-enable all interrupts

 *    soft ISR are low prioity jobs which can be very slow, thus all IRQs

 *    must be enabled while they run.

 *    Now hardware context wise we may still be in L2 ISR (not done rtie)

 *    still we must re-enable both L1 and L2 IRQs

 *  Another twist is prev scenario with flow being

 *     L1 ISR ==> interrupted by L2 ISR  ==> L2 soft ISR

 *     here we must not re-enable Ll as prev Ll Interrupt's h/w context will get

 *     over-written (this is deficiency in ARC700 Interrupt mechanism)

 */



#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS	/* Complex version for 2 IRQ levels */



void arch_local_irq_enable(void)

{



	unsigned long flags = arch_local_save_flags();



	/* Allow both L1 and L2 at the onset */

	flags |= (STATUS_E1_MASK | STATUS_E2_MASK);



	/* Called from hard ISR (between irq_enter and irq_exit) */

	if (in_irq()) {



		/* If in L2 ISR, don't re-enable any further IRQs as this can

		 * cause IRQ priorities to get upside down. e.g. it could allow

		 * L1 be taken while in L2 hard ISR which is wrong not only in

		 * theory, it can also cause the dreaded L1-L2-L1 scenario

		 */

		if (flags & STATUS_A2_MASK)

			flags &= ~(STATUS_E1_MASK | STATUS_E2_MASK);



		/* Even if in L1 ISR, allowe Higher prio L2 IRQs */

		else if (flags & STATUS_A1_MASK)

			flags &= ~(STATUS_E1_MASK);

	}



	/* called from soft IRQ, ideally we want to re-enable all levels */



	else if (in_softirq()) {



		/* However if this is case of L1 interrupted by L2,

		 * re-enabling both may cause whaco L1-L2-L1 scenario

		 * because ARC700 allows level 1 to interrupt an active L2 ISR

		 * Thus we disable both

		 * However some code, executing in soft ISR wants some IRQs

		 * to be enabled so we re-enable L2 only

		 *

		 * How do we determine L1 intr by L2

		 *  -A2 is set (means in L2 ISR)

		 *  -E1 is set in this ISR's pt_regs->status32 which is

		 *      saved copy of status32_l2 when l2 ISR happened

		 */

		struct pt_regs *pt = get_irq_regs();



		if ((flags & STATUS_A2_MASK) && pt &&

		    (pt->status32 & STATUS_A1_MASK)) {

			/*flags &= ~(STATUS_E1_MASK | STATUS_E2_MASK); */

			flags &= ~(STATUS_E1_MASK);

		}

	}



	arch_local_irq_restore(flags);

}



#else /* ! CONFIG_ARC_COMPACT_IRQ_LEVELS */



/*

 * Simpler version for only 1 level of interrupt

 * Here we only Worry about Level 1 Bits

 */

void arch_local_irq_enable(void)

{

	unsigned long flags;



	/*

	 * ARC IDE Drivers tries to re-enable interrupts from hard-isr

	 * context which is simply wrong

	 */

	if (in_irq()) {

		WARN_ONCE(1, "IRQ enabled from hard-isr");

		return;

	}



	flags = arch_local_save_flags();

	flags |= (STATUS_E1_MASK | STATUS_E2_MASK);

	arch_local_irq_restore(flags);

}

#endif

EXPORT_SYMBOL(arch_local_irq_enable);

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