--- /dev/null
+/*
+ * Support for adapter interruptions
+ *
+ * Copyright IBM Corp. 1999, 2007
+ * Author(s): Ingo Adlung <adlung@de.ibm.com>
+ * Cornelia Huck <cornelia.huck@de.ibm.com>
+ * Arnd Bergmann <arndb@de.ibm.com>
+ * Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
+ */
+
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/kernel_stat.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/rculist.h>
+#include <linux/slab.h>
+
+#include <asm/airq.h>
+#include <asm/isc.h>
+
+#include "cio.h"
+#include "cio_debug.h"
+#include "ioasm.h"
+
+static DEFINE_SPINLOCK(airq_lists_lock);
+static struct hlist_head airq_lists[MAX_ISC+1];
+
+/**
+ * register_adapter_interrupt() - register adapter interrupt handler
+ * @airq: pointer to adapter interrupt descriptor
+ *
+ * Returns 0 on success, or -EINVAL.
+ */
+int register_adapter_interrupt(struct airq_struct *airq)
+{
+ char dbf_txt[32];
+
+ if (!airq->handler || airq->isc > MAX_ISC)
+ return -EINVAL;
+ if (!airq->lsi_ptr) {
+ airq->lsi_ptr = kzalloc(1, GFP_KERNEL);
+ if (!airq->lsi_ptr)
+ return -ENOMEM;
+ airq->flags |= AIRQ_PTR_ALLOCATED;
+ }
+ if (!airq->lsi_mask)
+ airq->lsi_mask = 0xff;
+ snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%p", airq);
+ CIO_TRACE_EVENT(4, dbf_txt);
+ isc_register(airq->isc);
+ spin_lock(&airq_lists_lock);
+ hlist_add_head_rcu(&airq->list, &airq_lists[airq->isc]);
+ spin_unlock(&airq_lists_lock);
+ return 0;
+}
+EXPORT_SYMBOL(register_adapter_interrupt);
+
+/**
+ * unregister_adapter_interrupt - unregister adapter interrupt handler
+ * @airq: pointer to adapter interrupt descriptor
+ */
+void unregister_adapter_interrupt(struct airq_struct *airq)
+{
+ char dbf_txt[32];
+
+ if (hlist_unhashed(&airq->list))
+ return;
+ snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%p", airq);
+ CIO_TRACE_EVENT(4, dbf_txt);
+ spin_lock(&airq_lists_lock);
+ hlist_del_rcu(&airq->list);
+ spin_unlock(&airq_lists_lock);
+ synchronize_rcu();
+ isc_unregister(airq->isc);
+ if (airq->flags & AIRQ_PTR_ALLOCATED) {
+ kfree(airq->lsi_ptr);
+ airq->lsi_ptr = NULL;
+ airq->flags &= ~AIRQ_PTR_ALLOCATED;
+ }
+}
+EXPORT_SYMBOL(unregister_adapter_interrupt);
+
+static irqreturn_t do_airq_interrupt(int irq, void *dummy)
+{
+ struct tpi_info *tpi_info;
+ struct airq_struct *airq;
+ struct hlist_head *head;
+
+ set_cpu_flag(CIF_NOHZ_DELAY);
+ tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
+ head = &airq_lists[tpi_info->isc];
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(airq, head, list)
+ if ((*airq->lsi_ptr & airq->lsi_mask) != 0)
+ airq->handler(airq);
+ rcu_read_unlock();
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction airq_interrupt = {
+ .name = "AIO",
+ .handler = do_airq_interrupt,
+};
+
+void __init init_airq_interrupts(void)
+{
+ irq_set_chip_and_handler(THIN_INTERRUPT,
+ &dummy_irq_chip, handle_percpu_irq);
+ setup_irq(THIN_INTERRUPT, &airq_interrupt);
+}
+
+/**
+ * airq_iv_create - create an interrupt vector
+ * @bits: number of bits in the interrupt vector
+ * @flags: allocation flags
+ *
+ * Returns a pointer to an interrupt vector structure
+ */
+struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags)
+{
+ struct airq_iv *iv;
+ unsigned long size;
+
+ iv = kzalloc(sizeof(*iv), GFP_KERNEL);
+ if (!iv)
+ goto out;
+ iv->bits = bits;
+ size = BITS_TO_LONGS(bits) * sizeof(unsigned long);
+ iv->vector = kzalloc(size, GFP_KERNEL);
+ if (!iv->vector)
+ goto out_free;
+ if (flags & AIRQ_IV_ALLOC) {
+ iv->avail = kmalloc(size, GFP_KERNEL);
+ if (!iv->avail)
+ goto out_free;
+ memset(iv->avail, 0xff, size);
+ iv->end = 0;
+ } else
+ iv->end = bits;
+ if (flags & AIRQ_IV_BITLOCK) {
+ iv->bitlock = kzalloc(size, GFP_KERNEL);
+ if (!iv->bitlock)
+ goto out_free;
+ }
+ if (flags & AIRQ_IV_PTR) {
+ size = bits * sizeof(unsigned long);
+ iv->ptr = kzalloc(size, GFP_KERNEL);
+ if (!iv->ptr)
+ goto out_free;
+ }
+ if (flags & AIRQ_IV_DATA) {
+ size = bits * sizeof(unsigned int);
+ iv->data = kzalloc(size, GFP_KERNEL);
+ if (!iv->data)
+ goto out_free;
+ }
+ spin_lock_init(&iv->lock);
+ return iv;
+
+out_free:
+ kfree(iv->ptr);
+ kfree(iv->bitlock);
+ kfree(iv->avail);
+ kfree(iv->vector);
+ kfree(iv);
+out:
+ return NULL;
+}
+EXPORT_SYMBOL(airq_iv_create);
+
+/**
+ * airq_iv_release - release an interrupt vector
+ * @iv: pointer to interrupt vector structure
+ */
+void airq_iv_release(struct airq_iv *iv)
+{
+ kfree(iv->data);
+ kfree(iv->ptr);
+ kfree(iv->bitlock);
+ kfree(iv->vector);
+ kfree(iv->avail);
+ kfree(iv);
+}
+EXPORT_SYMBOL(airq_iv_release);
+
+/**
+ * airq_iv_alloc - allocate irq bits from an interrupt vector
+ * @iv: pointer to an interrupt vector structure
+ * @num: number of consecutive irq bits to allocate
+ *
+ * Returns the bit number of the first irq in the allocated block of irqs,
+ * or -1UL if no bit is available or the AIRQ_IV_ALLOC flag has not been
+ * specified
+ */
+unsigned long airq_iv_alloc(struct airq_iv *iv, unsigned long num)
+{
+ unsigned long bit, i, flags;
+
+ if (!iv->avail || num == 0)
+ return -1UL;
+ spin_lock_irqsave(&iv->lock, flags);
+ bit = find_first_bit_inv(iv->avail, iv->bits);
+ while (bit + num <= iv->bits) {
+ for (i = 1; i < num; i++)
+ if (!test_bit_inv(bit + i, iv->avail))
+ break;
+ if (i >= num) {
+ /* Found a suitable block of irqs */
+ for (i = 0; i < num; i++)
+ clear_bit_inv(bit + i, iv->avail);
+ if (bit + num >= iv->end)
+ iv->end = bit + num + 1;
+ break;
+ }
+ bit = find_next_bit_inv(iv->avail, iv->bits, bit + i + 1);
+ }
+ if (bit + num > iv->bits)
+ bit = -1UL;
+ spin_unlock_irqrestore(&iv->lock, flags);
+ return bit;
+}
+EXPORT_SYMBOL(airq_iv_alloc);
+
+/**
+ * airq_iv_free - free irq bits of an interrupt vector
+ * @iv: pointer to interrupt vector structure
+ * @bit: number of the first irq bit to free
+ * @num: number of consecutive irq bits to free
+ */
+void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num)
+{
+ unsigned long i, flags;
+
+ if (!iv->avail || num == 0)
+ return;
+ spin_lock_irqsave(&iv->lock, flags);
+ for (i = 0; i < num; i++) {
+ /* Clear (possibly left over) interrupt bit */
+ clear_bit_inv(bit + i, iv->vector);
+ /* Make the bit positions available again */
+ set_bit_inv(bit + i, iv->avail);
+ }
+ if (bit + num >= iv->end) {
+ /* Find new end of bit-field */
+ while (iv->end > 0 && !test_bit_inv(iv->end - 1, iv->avail))
+ iv->end--;
+ }
+ spin_unlock_irqrestore(&iv->lock, flags);
+}
+EXPORT_SYMBOL(airq_iv_free);
+
+/**
+ * airq_iv_scan - scan interrupt vector for non-zero bits
+ * @iv: pointer to interrupt vector structure
+ * @start: bit number to start the search
+ * @end: bit number to end the search
+ *
+ * Returns the bit number of the next non-zero interrupt bit, or
+ * -1UL if the scan completed without finding any more any non-zero bits.
+ */
+unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start,
+ unsigned long end)
+{
+ unsigned long bit;
+
+ /* Find non-zero bit starting from 'ivs->next'. */
+ bit = find_next_bit_inv(iv->vector, end, start);
+ if (bit >= end)
+ return -1UL;
+ clear_bit_inv(bit, iv->vector);
+ return bit;
+}
+EXPORT_SYMBOL(airq_iv_scan);
Code Review / kvmfornfv.git / blobdiff