1 files changed, 228 insertions, 103 deletions

diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c
index bc10220f684..00bfbee0af9 100644
--- a/drivers/s390/cio/airq.c
+++ b/drivers/s390/cio/airq.c
@@ -9,142 +9,267 @@
  */
 
 #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/rcupdate.h>
 
 #include <asm/airq.h>
 #include <asm/isc.h>
 
 #include "cio.h"
 #include "cio_debug.h"
+#include "ioasm.h"
 
-#define NR_AIRQS		32
-#define NR_AIRQS_PER_WORD	sizeof(unsigned long)
-#define NR_AIRQ_WORDS		(NR_AIRQS / NR_AIRQS_PER_WORD)
+static DEFINE_SPINLOCK(airq_lists_lock);
+static struct hlist_head airq_lists[MAX_ISC+1];
 
-union indicator_t {
-	unsigned long word[NR_AIRQ_WORDS];
-	unsigned char byte[NR_AIRQS];
-} __attribute__((packed));
+/**
+ * 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];
 
-struct airq_t {
-	adapter_int_handler_t handler;
-	void *drv_data;
-};
+	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);
 
-static union indicator_t indicators[MAX_ISC+1];
-static struct airq_t *airqs[MAX_ISC+1][NR_AIRQS];
+/**
+ * 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];
 
-static int register_airq(struct airq_t *airq, u8 isc)
+	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)
 {
-	int i;
+	struct tpi_info *tpi_info;
+	struct airq_struct *airq;
+	struct hlist_head *head;
+
+	__this_cpu_write(s390_idle.nohz_delay, 1);
+	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,
+};
 
-	for (i = 0; i < NR_AIRQS; i++)
-		if (!cmpxchg(&airqs[isc][i], NULL, airq))
-			return i;
-	return -ENOMEM;
+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);
 }
 
 /**
- * s390_register_adapter_interrupt() - register adapter interrupt handler
- * @handler: adapter handler to be registered
- * @drv_data: driver data passed with each call to the handler
- * @isc: isc for which the handler should be called
+ * airq_iv_create - create an interrupt vector
+ * @bits: number of bits in the interrupt vector
+ * @flags: allocation flags
  *
- * Returns:
- *  Pointer to the indicator to be used on success
- *  ERR_PTR() if registration failed
+ * Returns a pointer to an interrupt vector structure
  */
-void *s390_register_adapter_interrupt(adapter_int_handler_t handler,
-				      void *drv_data, u8 isc)
+struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags)
 {
-	struct airq_t *airq;
-	char dbf_txt[16];
-	int ret;
-
-	if (isc > MAX_ISC)
-		return ERR_PTR(-EINVAL);
-	airq = kmalloc(sizeof(struct airq_t), GFP_KERNEL);
-	if (!airq) {
-		ret = -ENOMEM;
+	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;
 	}
-	airq->handler = handler;
-	airq->drv_data = drv_data;
+	spin_lock_init(&iv->lock);
+	return iv;
 
-	ret = register_airq(airq, isc);
+out_free:
+	kfree(iv->ptr);
+	kfree(iv->bitlock);
+	kfree(iv->avail);
+	kfree(iv->vector);
+	kfree(iv);
 out:
-	snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%d", ret);
-	CIO_TRACE_EVENT(4, dbf_txt);
-	if (ret < 0) {
-		kfree(airq);
-		return ERR_PTR(ret);
-	} else
-		return &indicators[isc].byte[ret];
+	return NULL;
 }
-EXPORT_SYMBOL(s390_register_adapter_interrupt);
+EXPORT_SYMBOL(airq_iv_create);
 
 /**
- * s390_unregister_adapter_interrupt - unregister adapter interrupt handler
- * @ind: indicator for which the handler is to be unregistered
- * @isc: interruption subclass
+ * airq_iv_release - release an interrupt vector
+ * @iv: pointer to interrupt vector structure
  */
-void s390_unregister_adapter_interrupt(void *ind, u8 isc)
+void airq_iv_release(struct airq_iv *iv)
 {
-	struct airq_t *airq;
-	char dbf_txt[16];
-	int i;
-
-	i = (int) ((addr_t) ind) - ((addr_t) &indicators[isc].byte[0]);
-	snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%d", i);
-	CIO_TRACE_EVENT(4, dbf_txt);
-	indicators[isc].byte[i] = 0;
-	airq = xchg(&airqs[isc][i], NULL);
-	/*
-	 * Allow interrupts to complete. This will ensure that the airq handle
-	 * is no longer referenced by any interrupt handler.
-	 */
-	synchronize_sched();
-	kfree(airq);
+	kfree(iv->data);
+	kfree(iv->ptr);
+	kfree(iv->bitlock);
+	kfree(iv->vector);
+	kfree(iv->avail);
+	kfree(iv);
 }
-EXPORT_SYMBOL(s390_unregister_adapter_interrupt);
-
-#define INDICATOR_MASK	(0xffUL << ((NR_AIRQS_PER_WORD - 1) * 8))
+EXPORT_SYMBOL(airq_iv_release);
 
-void do_adapter_IO(u8 isc)
+/**
+ * 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)
 {
-	int w;
-	int i;
-	unsigned long word;
-	struct airq_t *airq;
-
-	/*
-	 * Access indicator array in word-sized chunks to minimize storage
-	 * fetch operations.
-	 */
-	for (w = 0; w < NR_AIRQ_WORDS; w++) {
-		word = indicators[isc].word[w];
-		i = w * NR_AIRQS_PER_WORD;
-		/*
-		 * Check bytes within word for active indicators.
-		 */
-		while (word) {
-			if (word & INDICATOR_MASK) {
-				airq = airqs[isc][i];
-				/* Make sure gcc reads from airqs only once. */
-				barrier();
-				if (likely(airq))
-					airq->handler(&indicators[isc].byte[i],
-						      airq->drv_data);
-				else
-					/*
-					 * Reset ill-behaved indicator.
-					 */
-					indicators[isc].byte[i] = 0;
-			}
-			word <<= 8;
-			i++;
+	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);