mirror of https://gitee.com/openkylin/linux.git
49 lines
919 B
C
49 lines
919 B
C
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/*
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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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#include <linux/init.h>
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#include <linux/irq.h>
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#include <linux/types.h>
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#include <asm/barrier.h>
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static DECLARE_BITMAP(irq_map, NR_IRQS);
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int allocate_irqno(void)
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{
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int irq;
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again:
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irq = find_first_zero_bit(irq_map, NR_IRQS);
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if (irq >= NR_IRQS)
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return -ENOSPC;
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if (test_and_set_bit(irq, irq_map))
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goto again;
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return irq;
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}
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/*
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* Allocate the 16 legacy interrupts for i8259 devices. This happens early
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* in the kernel initialization so treating allocation failure as BUG() is
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* ok.
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*/
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void __init alloc_legacy_irqno(void)
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{
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int i;
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for (i = 0; i <= 16; i++)
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BUG_ON(test_and_set_bit(i, irq_map));
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}
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void free_irqno(unsigned int irq)
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{
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smp_mb__before_atomic();
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clear_bit(irq, irq_map);
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smp_mb__after_atomic();
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}
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