hardirq.h

来自「Linux Kernel 2.6.9 for OMAP1710」· C头文件 代码 · 共 65 行

/*
 * 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) 1997, 1998, 1999, 2000, 2001 by Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2001 MIPS Technologies, Inc.
 */
#ifndef _ASM_HARDIRQ_H
#define _ASM_HARDIRQ_H

#include <linux/config.h>
#include <linux/threads.h>
#include <linux/irq.h>

typedef struct {
	unsigned int __softirq_pending;
} ____cacheline_aligned irq_cpustat_t;

#include <linux/irq_cpustat.h>	/* Standard mappings for irq_cpustat_t above */

/*
 * We put the hardirq and softirq counter into the preemption
 * counter. The bitmask has the following meaning:
 *
 * - bits 0-7 are the preemption count (max preemption depth: 256)
 * - bits 8-15 are the softirq count (max # of softirqs: 256)
 * - bits 16-23 are the hardirq count (max # of hardirqs: 256)
 *
 * - ( bit 26 is the PREEMPT_ACTIVE flag. )
 *
 * PREEMPT_MASK: 0x000000ff
 * SOFTIRQ_MASK: 0x0000ff00
 * HARDIRQ_MASK: 0x00ff0000
 */

#define PREEMPT_BITS	8
#define SOFTIRQ_BITS	8
#define HARDIRQ_BITS	8

#define PREEMPT_SHIFT	0
#define SOFTIRQ_SHIFT	(PREEMPT_SHIFT + PREEMPT_BITS)
#define HARDIRQ_SHIFT	(SOFTIRQ_SHIFT + SOFTIRQ_BITS)

/*
 * The hardirq mask has to be large enough to have
 * space for potentially all IRQ sources in the system
 * nesting on a single CPU:
 */
#if (1 << HARDIRQ_BITS) < NR_IRQS
# error HARDIRQ_BITS is too low!
#endif

#define irq_enter()		(preempt_count() += HARDIRQ_OFFSET)
#define irq_exit()                                                     \
do {                                                                   \
	preempt_count() -= IRQ_EXIT_OFFSET;                     \
	if (!in_interrupt() && softirq_pending(smp_processor_id())) \
		do_softirq();                                   \
	preempt_enable_no_resched();                            \
} while (0)

#endif /* _ASM_HARDIRQ_H */