136 lines
3.1 KiB
C
136 lines
3.1 KiB
C
/*
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* Dynamic IRQ management
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*
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* Copyright (C) 2010 Paul Mundt
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*
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* Modelled after arch/x86/kernel/apic/io_apic.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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#define pr_fmt(fmt) "intc: " fmt
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#include <linux/irq.h>
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#include <linux/bitmap.h>
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#include <linux/spinlock.h>
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#include "internals.h" /* only for activate_irq() damage.. */
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/*
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* The intc_irq_map provides a global map of bound IRQ vectors for a
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* given platform. Allocation of IRQs are either static through the CPU
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* vector map, or dynamic in the case of board mux vectors or MSI.
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*
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* As this is a central point for all IRQ controllers on the system,
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* each of the available sources are mapped out here. This combined with
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* sparseirq makes it quite trivial to keep the vector map tightly packed
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* when dynamically creating IRQs, as well as tying in to otherwise
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* unused irq_desc positions in the sparse array.
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*/
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static DECLARE_BITMAP(intc_irq_map, NR_IRQS);
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static DEFINE_RAW_SPINLOCK(vector_lock);
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/*
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* Dynamic IRQ allocation and deallocation
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*/
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unsigned int create_irq_nr(unsigned int irq_want, int node)
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{
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unsigned int irq = 0, new;
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unsigned long flags;
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struct irq_desc *desc;
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raw_spin_lock_irqsave(&vector_lock, flags);
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/*
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* First try the wanted IRQ
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*/
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if (test_and_set_bit(irq_want, intc_irq_map) == 0) {
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new = irq_want;
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} else {
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/* .. then fall back to scanning. */
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new = find_first_zero_bit(intc_irq_map, nr_irqs);
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if (unlikely(new == nr_irqs))
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goto out_unlock;
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__set_bit(new, intc_irq_map);
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}
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desc = irq_to_desc_alloc_node(new, node);
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if (unlikely(!desc)) {
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pr_err("can't get irq_desc for %d\n", new);
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goto out_unlock;
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}
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desc = move_irq_desc(desc, node);
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irq = new;
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out_unlock:
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raw_spin_unlock_irqrestore(&vector_lock, flags);
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if (irq > 0) {
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dynamic_irq_init(irq);
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activate_irq(irq);
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}
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return irq;
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}
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int create_irq(void)
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{
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int nid = cpu_to_node(smp_processor_id());
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int irq;
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irq = create_irq_nr(NR_IRQS_LEGACY, nid);
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if (irq == 0)
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irq = -1;
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return irq;
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}
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void destroy_irq(unsigned int irq)
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{
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unsigned long flags;
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dynamic_irq_cleanup(irq);
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raw_spin_lock_irqsave(&vector_lock, flags);
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__clear_bit(irq, intc_irq_map);
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raw_spin_unlock_irqrestore(&vector_lock, flags);
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}
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int reserve_irq_vector(unsigned int irq)
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{
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unsigned long flags;
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int ret = 0;
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raw_spin_lock_irqsave(&vector_lock, flags);
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if (test_and_set_bit(irq, intc_irq_map))
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ret = -EBUSY;
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raw_spin_unlock_irqrestore(&vector_lock, flags);
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return ret;
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}
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void reserve_intc_vectors(struct intc_vect *vectors, unsigned int nr_vecs)
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{
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unsigned long flags;
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int i;
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raw_spin_lock_irqsave(&vector_lock, flags);
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for (i = 0; i < nr_vecs; i++)
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__set_bit(evt2irq(vectors[i].vect), intc_irq_map);
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raw_spin_unlock_irqrestore(&vector_lock, flags);
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}
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void reserve_irq_legacy(void)
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{
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unsigned long flags;
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int i, j;
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raw_spin_lock_irqsave(&vector_lock, flags);
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j = find_first_bit(intc_irq_map, nr_irqs);
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for (i = 0; i < j; i++)
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__set_bit(i, intc_irq_map);
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raw_spin_unlock_irqrestore(&vector_lock, flags);
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}
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