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![Martin Schwidefsky](/assets/img/avatar_default.png)
The PCI code is the first user of adapter interrupts vectors. Add a set of helpers to airq.c to separate the adatper interrupt code from the PCI bits. The helpers allow for adapter interrupt vectors of any size. Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
248 lines
6 KiB
C
248 lines
6 KiB
C
/*
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* Support for adapter interruptions
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*
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* Copyright IBM Corp. 1999, 2007
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* Author(s): Ingo Adlung <adlung@de.ibm.com>
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* Cornelia Huck <cornelia.huck@de.ibm.com>
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* Arnd Bergmann <arndb@de.ibm.com>
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* Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
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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/kernel_stat.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/rculist.h>
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#include <linux/slab.h>
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#include <asm/airq.h>
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#include <asm/isc.h>
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#include "cio.h"
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#include "cio_debug.h"
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#include "ioasm.h"
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static DEFINE_SPINLOCK(airq_lists_lock);
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static struct hlist_head airq_lists[MAX_ISC+1];
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/**
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* register_adapter_interrupt() - register adapter interrupt handler
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* @airq: pointer to adapter interrupt descriptor
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*
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* Returns 0 on success, or -EINVAL.
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*/
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int register_adapter_interrupt(struct airq_struct *airq)
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{
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char dbf_txt[32];
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if (!airq->handler || airq->isc > MAX_ISC)
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return -EINVAL;
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if (!airq->lsi_ptr) {
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airq->lsi_ptr = kzalloc(1, GFP_KERNEL);
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if (!airq->lsi_ptr)
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return -ENOMEM;
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airq->flags |= AIRQ_PTR_ALLOCATED;
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}
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if (!airq->lsi_mask)
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airq->lsi_mask = 0xff;
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snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%p", airq);
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CIO_TRACE_EVENT(4, dbf_txt);
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isc_register(airq->isc);
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spin_lock(&airq_lists_lock);
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hlist_add_head_rcu(&airq->list, &airq_lists[airq->isc]);
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spin_unlock(&airq_lists_lock);
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return 0;
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}
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EXPORT_SYMBOL(register_adapter_interrupt);
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/**
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* unregister_adapter_interrupt - unregister adapter interrupt handler
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* @airq: pointer to adapter interrupt descriptor
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*/
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void unregister_adapter_interrupt(struct airq_struct *airq)
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{
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char dbf_txt[32];
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if (hlist_unhashed(&airq->list))
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return;
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snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%p", airq);
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CIO_TRACE_EVENT(4, dbf_txt);
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spin_lock(&airq_lists_lock);
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hlist_del_rcu(&airq->list);
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spin_unlock(&airq_lists_lock);
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synchronize_rcu();
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isc_unregister(airq->isc);
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if (airq->flags & AIRQ_PTR_ALLOCATED) {
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kfree(airq->lsi_ptr);
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airq->lsi_ptr = NULL;
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airq->flags &= ~AIRQ_PTR_ALLOCATED;
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}
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}
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EXPORT_SYMBOL(unregister_adapter_interrupt);
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void do_adapter_IO(u8 isc)
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{
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struct airq_struct *airq;
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struct hlist_head *head;
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head = &airq_lists[isc];
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rcu_read_lock();
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hlist_for_each_entry_rcu(airq, head, list)
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if ((*airq->lsi_ptr & airq->lsi_mask) != 0)
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airq->handler(airq);
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rcu_read_unlock();
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}
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/**
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* airq_iv_create - create an interrupt vector
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* @bits: number of bits in the interrupt vector
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* @flags: allocation flags
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*
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* Returns a pointer to an interrupt vector structure
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*/
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struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags)
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{
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struct airq_iv *iv;
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unsigned long size;
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iv = kzalloc(sizeof(*iv), GFP_KERNEL);
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if (!iv)
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goto out;
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iv->bits = bits;
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size = BITS_TO_LONGS(bits) * sizeof(unsigned long);
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iv->vector = kzalloc(size, GFP_KERNEL);
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if (!iv->vector)
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goto out_free;
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if (flags & AIRQ_IV_ALLOC) {
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iv->avail = kmalloc(size, GFP_KERNEL);
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if (!iv->avail)
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goto out_free;
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memset(iv->avail, 0xff, size);
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iv->end = 0;
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} else
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iv->end = bits;
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if (flags & AIRQ_IV_BITLOCK) {
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iv->bitlock = kzalloc(size, GFP_KERNEL);
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if (!iv->bitlock)
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goto out_free;
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}
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if (flags & AIRQ_IV_PTR) {
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size = bits * sizeof(unsigned long);
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iv->ptr = kzalloc(size, GFP_KERNEL);
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if (!iv->ptr)
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goto out_free;
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}
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if (flags & AIRQ_IV_DATA) {
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size = bits * sizeof(unsigned int);
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iv->data = kzalloc(size, GFP_KERNEL);
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if (!iv->data)
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goto out_free;
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}
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spin_lock_init(&iv->lock);
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return iv;
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out_free:
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kfree(iv->ptr);
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kfree(iv->bitlock);
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kfree(iv->avail);
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kfree(iv->vector);
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kfree(iv);
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out:
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return NULL;
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}
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EXPORT_SYMBOL(airq_iv_create);
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/**
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* airq_iv_release - release an interrupt vector
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* @iv: pointer to interrupt vector structure
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*/
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void airq_iv_release(struct airq_iv *iv)
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{
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kfree(iv->data);
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kfree(iv->ptr);
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kfree(iv->bitlock);
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kfree(iv->vector);
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kfree(iv->avail);
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kfree(iv);
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}
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EXPORT_SYMBOL(airq_iv_release);
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/**
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* airq_iv_alloc_bit - allocate an irq bit from an interrupt vector
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* @iv: pointer to an interrupt vector structure
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*
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* Returns the bit number of the allocated irq, or -1UL if no bit
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* is available or the AIRQ_IV_ALLOC flag has not been specified
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*/
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unsigned long airq_iv_alloc_bit(struct airq_iv *iv)
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{
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const unsigned long be_to_le = BITS_PER_LONG - 1;
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unsigned long bit;
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if (!iv->avail)
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return -1UL;
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spin_lock(&iv->lock);
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bit = find_first_bit_left(iv->avail, iv->bits);
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if (bit < iv->bits) {
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clear_bit(bit ^ be_to_le, iv->avail);
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if (bit >= iv->end)
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iv->end = bit + 1;
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} else
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bit = -1UL;
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spin_unlock(&iv->lock);
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return bit;
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}
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EXPORT_SYMBOL(airq_iv_alloc_bit);
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/**
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* airq_iv_free_bit - free an irq bit of an interrupt vector
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* @iv: pointer to interrupt vector structure
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* @bit: number of the irq bit to free
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*/
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void airq_iv_free_bit(struct airq_iv *iv, unsigned long bit)
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{
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const unsigned long be_to_le = BITS_PER_LONG - 1;
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if (!iv->avail)
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return;
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spin_lock(&iv->lock);
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/* Clear (possibly left over) interrupt bit */
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clear_bit(bit ^ be_to_le, iv->vector);
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/* Make the bit position available again */
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set_bit(bit ^ be_to_le, iv->avail);
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if (bit == iv->end - 1) {
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/* Find new end of bit-field */
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while (--iv->end > 0)
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if (!test_bit((iv->end - 1) ^ be_to_le, iv->avail))
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break;
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}
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spin_unlock(&iv->lock);
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}
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EXPORT_SYMBOL(airq_iv_free_bit);
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/**
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* airq_iv_scan - scan interrupt vector for non-zero bits
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* @iv: pointer to interrupt vector structure
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* @start: bit number to start the search
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* @end: bit number to end the search
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*
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* Returns the bit number of the next non-zero interrupt bit, or
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* -1UL if the scan completed without finding any more any non-zero bits.
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*/
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unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start,
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unsigned long end)
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{
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const unsigned long be_to_le = BITS_PER_LONG - 1;
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unsigned long bit;
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/* Find non-zero bit starting from 'ivs->next'. */
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bit = find_next_bit_left(iv->vector, end, start);
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if (bit >= end)
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return -1UL;
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/* Clear interrupt bit (find left uses big-endian bit numbers) */
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clear_bit(bit ^ be_to_le, iv->vector);
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return bit;
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}
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EXPORT_SYMBOL(airq_iv_scan);
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