1 files changed, 315 insertions, 0 deletions
diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c
new file mode 100644
index 000000000..34967e672
--- /dev/null
+++ b/drivers/s390/cio/airq.c
@@ -0,0 +1,315 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *    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 <linux/dmapool.h>
+
+#include <asm/airq.h>
+#include <asm/isc.h>
+#include <asm/cio.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];
+
+static struct dma_pool *airq_iv_cache;
+
+/**
+ * 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 = cio_dma_zalloc(1);
+		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) {
+		cio_dma_free(airq->lsi_ptr, 1);
+		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 = &get_irq_regs()->tpi_info;
+	trace_s390_cio_adapter_int(tpi_info);
+	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, tpi_info);
+	rcu_read_unlock();
+
+	return IRQ_HANDLED;
+}
+
+void __init init_airq_interrupts(void)
+{
+	irq_set_chip_and_handler(THIN_INTERRUPT,
+				 &dummy_irq_chip, handle_percpu_irq);
+	if (request_irq(THIN_INTERRUPT, do_airq_interrupt, 0, "AIO", NULL))
+		panic("Failed to register AIO interrupt\n");
+}
+
+static inline unsigned long iv_size(unsigned long bits)
+{
+	return BITS_TO_LONGS(bits) * sizeof(unsigned long);
+}
+
+/**
+ * airq_iv_create - create an interrupt vector
+ * @bits: number of bits in the interrupt vector
+ * @flags: allocation flags
+ * @vec: pointer to pinned guest memory if AIRQ_IV_GUESTVEC
+ *
+ * Returns a pointer to an interrupt vector structure
+ */
+struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags,
+			       unsigned long *vec)
+{
+	struct airq_iv *iv;
+	unsigned long size;
+
+	iv = kzalloc(sizeof(*iv), GFP_KERNEL);
+	if (!iv)
+		goto out;
+	iv->bits = bits;
+	iv->flags = flags;
+	size = iv_size(bits);
+
+	if (flags & AIRQ_IV_CACHELINE) {
+		if ((cache_line_size() * BITS_PER_BYTE) < bits
+				|| !airq_iv_cache)
+			goto out_free;
+
+		iv->vector = dma_pool_zalloc(airq_iv_cache, GFP_KERNEL,
+					     &iv->vector_dma);
+		if (!iv->vector)
+			goto out_free;
+	} else if (flags & AIRQ_IV_GUESTVEC) {
+		iv->vector = vec;
+	} else {
+		iv->vector = cio_dma_zalloc(size);
+		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);
+	if (iv->flags & AIRQ_IV_CACHELINE && iv->vector)
+		dma_pool_free(airq_iv_cache, iv->vector, iv->vector_dma);
+	else if (!(iv->flags & AIRQ_IV_GUESTVEC))
+		cio_dma_free(iv->vector, size);
+	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);
+	if (iv->flags & AIRQ_IV_CACHELINE)
+		dma_pool_free(airq_iv_cache, iv->vector, iv->vector_dma);
+	else if (!(iv->flags & AIRQ_IV_GUESTVEC))
+		cio_dma_free(iv->vector, iv_size(iv->bits));
+	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);
+
+int __init airq_init(void)
+{
+	airq_iv_cache = dma_pool_create("airq_iv_cache", cio_get_dma_css_dev(),
+					cache_line_size(),
+					cache_line_size(), PAGE_SIZE);
+	if (!airq_iv_cache)
+		return -ENOMEM;
+	return 0;
+}