Merge tag 'kvm-s390-20140304' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-next

2 files changed, 337 insertions, 42 deletions

diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c
index f055df0b167f..445564c790f6 100644
--- a/drivers/s390/cio/airq.c
+++ b/drivers/s390/cio/airq.c
@@ -186,55 +186,71 @@ void airq_iv_release(struct airq_iv *iv)
 EXPORT_SYMBOL(airq_iv_release);
 
 /**
- * airq_iv_alloc_bit - allocate an irq bit from an interrupt vector
+ * 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 allocated irq, or -1UL if no bit
- * is available or the AIRQ_IV_ALLOC flag has not been specified
+ * 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_bit(struct airq_iv *iv)
+unsigned long airq_iv_alloc(struct airq_iv *iv, unsigned long num)
 {
-	unsigned long bit;
+	unsigned long bit, i;
 
-	if (!iv->avail)
+	if (!iv->avail || num == 0)
 		return -1UL;
 	spin_lock(&iv->lock);
 	bit = find_first_bit_inv(iv->avail, iv->bits);
-	if (bit < iv->bits) {
-		clear_bit_inv(bit, iv->avail);
-		if (bit >= iv->end)
-			iv->end = bit + 1;
-	} else
+	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(&iv->lock);
 	return bit;
 
 }
-EXPORT_SYMBOL(airq_iv_alloc_bit);
+EXPORT_SYMBOL(airq_iv_alloc);
 
 /**
- * airq_iv_free_bit - free an irq bit of an interrupt vector
+ * airq_iv_free - free irq bits of an interrupt vector
  * @iv: pointer to interrupt vector structure
- * @bit: number of the irq bit to free
+ * @bit: number of the first irq bit to free
+ * @num: number of consecutive irq bits to free
  */
-void airq_iv_free_bit(struct airq_iv *iv, unsigned long bit)
+void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num)
 {
-	if (!iv->avail)
+	unsigned long i;
+
+	if (!iv->avail || num == 0)
 		return;
 	spin_lock(&iv->lock);
-	/* Clear (possibly left over) interrupt bit */
-	clear_bit_inv(bit, iv->vector);
-	/* Make the bit position available again */
-	set_bit_inv(bit, iv->avail);
-	if (bit == iv->end - 1) {
+	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)
-			if (!test_bit_inv(iv->end - 1, iv->avail))
-				break;
+		while (iv->end > 0 && !test_bit_inv(iv->end - 1, iv->avail))
+			iv->end--;
 	}
 	spin_unlock(&iv->lock);
 }
-EXPORT_SYMBOL(airq_iv_free_bit);
+EXPORT_SYMBOL(airq_iv_free);
 
 /**
  * airq_iv_scan - scan interrupt vector for non-zero bits
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index 0fc584832001..6a2b5fdcd552 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -1,7 +1,7 @@
 /*
  * ccw based virtio transport
  *
- * Copyright IBM Corp. 2012
+ * Copyright IBM Corp. 2012, 2014
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License (version 2 only)
@@ -32,6 +32,8 @@
 #include <asm/cio.h>
 #include <asm/ccwdev.h>
 #include <asm/virtio-ccw.h>
+#include <asm/isc.h>
+#include <asm/airq.h>
 
 /*
  * virtio related functions
@@ -58,6 +60,8 @@ struct virtio_ccw_device {
 	unsigned long indicators;
 	unsigned long indicators2;
 	struct vq_config_block *config_block;
+	bool is_thinint;
+	void *airq_info;
 };
 
 struct vq_info_block {
@@ -72,15 +76,38 @@ struct virtio_feature_desc {
 	__u8 index;
 } __packed;
 
+struct virtio_thinint_area {
+	unsigned long summary_indicator;
+	unsigned long indicator;
+	u64 bit_nr;
+	u8 isc;
+} __packed;
+
 struct virtio_ccw_vq_info {
 	struct virtqueue *vq;
 	int num;
 	void *queue;
 	struct vq_info_block *info_block;
+	int bit_nr;
 	struct list_head node;
 	long cookie;
 };
 
+#define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
+
+#define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
+#define MAX_AIRQ_AREAS 20
+
+static int virtio_ccw_use_airq = 1;
+
+struct airq_info {
+	rwlock_t lock;
+	u8 summary_indicator;
+	struct airq_struct airq;
+	struct airq_iv *aiv;
+};
+static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
+
 #define CCW_CMD_SET_VQ 0x13
 #define CCW_CMD_VDEV_RESET 0x33
 #define CCW_CMD_SET_IND 0x43
@@ -91,6 +118,7 @@ struct virtio_ccw_vq_info {
 #define CCW_CMD_WRITE_CONF 0x21
 #define CCW_CMD_WRITE_STATUS 0x31
 #define CCW_CMD_READ_VQ_CONF 0x32
+#define CCW_CMD_SET_IND_ADAPTER 0x73
 
 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
 #define VIRTIO_CCW_DOING_RESET 0x00040000
@@ -102,6 +130,7 @@ struct virtio_ccw_vq_info {
 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
+#define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
 
 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
@@ -109,6 +138,125 @@ static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
 	return container_of(vdev, struct virtio_ccw_device, vdev);
 }
 
+static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
+{
+	unsigned long i, flags;
+
+	write_lock_irqsave(&info->lock, flags);
+	for (i = 0; i < airq_iv_end(info->aiv); i++) {
+		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
+			airq_iv_free_bit(info->aiv, i);
+			airq_iv_set_ptr(info->aiv, i, 0);
+			break;
+		}
+	}
+	write_unlock_irqrestore(&info->lock, flags);
+}
+
+static void virtio_airq_handler(struct airq_struct *airq)
+{
+	struct airq_info *info = container_of(airq, struct airq_info, airq);
+	unsigned long ai;
+
+	inc_irq_stat(IRQIO_VAI);
+	read_lock(&info->lock);
+	/* Walk through indicators field, summary indicator active. */
+	for (ai = 0;;) {
+		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
+		if (ai == -1UL)
+			break;
+		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
+	}
+	info->summary_indicator = 0;
+	smp_wmb();
+	/* Walk through indicators field, summary indicator not active. */
+	for (ai = 0;;) {
+		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
+		if (ai == -1UL)
+			break;
+		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
+	}
+	read_unlock(&info->lock);
+}
+
+static struct airq_info *new_airq_info(void)
+{
+	struct airq_info *info;
+	int rc;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return NULL;
+	rwlock_init(&info->lock);
+	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
+	if (!info->aiv) {
+		kfree(info);
+		return NULL;
+	}
+	info->airq.handler = virtio_airq_handler;
+	info->airq.lsi_ptr = &info->summary_indicator;
+	info->airq.lsi_mask = 0xff;
+	info->airq.isc = VIRTIO_AIRQ_ISC;
+	rc = register_adapter_interrupt(&info->airq);
+	if (rc) {
+		airq_iv_release(info->aiv);
+		kfree(info);
+		return NULL;
+	}
+	return info;
+}
+
+static void destroy_airq_info(struct airq_info *info)
+{
+	if (!info)
+		return;
+
+	unregister_adapter_interrupt(&info->airq);
+	airq_iv_release(info->aiv);
+	kfree(info);
+}
+
+static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
+					u64 *first, void **airq_info)
+{
+	int i, j;
+	struct airq_info *info;
+	unsigned long indicator_addr = 0;
+	unsigned long bit, flags;
+
+	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
+		if (!airq_areas[i])
+			airq_areas[i] = new_airq_info();
+		info = airq_areas[i];
+		if (!info)
+			return 0;
+		write_lock_irqsave(&info->lock, flags);
+		bit = airq_iv_alloc(info->aiv, nvqs);
+		if (bit == -1UL) {
+			/* Not enough vacancies. */
+			write_unlock_irqrestore(&info->lock, flags);
+			continue;
+		}
+		*first = bit;
+		*airq_info = info;
+		indicator_addr = (unsigned long)info->aiv->vector;
+		for (j = 0; j < nvqs; j++) {
+			airq_iv_set_ptr(info->aiv, bit + j,
+					(unsigned long)vqs[j]);
+		}
+		write_unlock_irqrestore(&info->lock, flags);
+	}
+	return indicator_addr;
+}
+
+static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
+{
+	struct virtio_ccw_vq_info *info;
+
+	list_for_each_entry(info, &vcdev->virtqueues, node)
+		drop_airq_indicator(info->vq, vcdev->airq_info);
+}
+
 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
 {
 	unsigned long flags;
@@ -145,6 +293,51 @@ static int ccw_io_helper(struct virtio_ccw_device *vcdev,
 	return ret ? ret : vcdev->err;
 }
 
+static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
+				      struct ccw1 *ccw)
+{
+	int ret;
+	unsigned long *indicatorp = NULL;
+	struct virtio_thinint_area *thinint_area = NULL;
+	struct airq_info *airq_info = vcdev->airq_info;
+
+	if (vcdev->is_thinint) {
+		thinint_area = kzalloc(sizeof(*thinint_area),
+				       GFP_DMA | GFP_KERNEL);
+		if (!thinint_area)
+			return;
+		thinint_area->summary_indicator =
+			(unsigned long) &airq_info->summary_indicator;
+		thinint_area->isc = VIRTIO_AIRQ_ISC;
+		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
+		ccw->count = sizeof(*thinint_area);
+		ccw->cda = (__u32)(unsigned long) thinint_area;
+	} else {
+		indicatorp = kmalloc(sizeof(&vcdev->indicators),
+				     GFP_DMA | GFP_KERNEL);
+		if (!indicatorp)
+			return;
+		*indicatorp = 0;
+		ccw->cmd_code = CCW_CMD_SET_IND;
+		ccw->count = sizeof(vcdev->indicators);
+		ccw->cda = (__u32)(unsigned long) indicatorp;
+	}
+	/* Deregister indicators from host. */
+	vcdev->indicators = 0;
+	ccw->flags = 0;
+	ret = ccw_io_helper(vcdev, ccw,
+			    vcdev->is_thinint ?
+			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
+			    VIRTIO_CCW_DOING_SET_IND);
+	if (ret && (ret != -ENODEV))
+		dev_info(&vcdev->cdev->dev,
+			 "Failed to deregister indicators (%d)\n", ret);
+	else if (vcdev->is_thinint)
+		virtio_ccw_drop_indicators(vcdev);
+	kfree(indicatorp);
+	kfree(thinint_area);
+}
+
 static inline long do_kvm_notify(struct subchannel_id schid,
 				 unsigned long queue_index,
 				 long cookie)
@@ -232,11 +425,13 @@ static void virtio_ccw_del_vqs(struct virtio_device *vdev)
 {
 	struct virtqueue *vq, *n;
 	struct ccw1 *ccw;
+	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 
 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 	if (!ccw)
 		return;
 
+	virtio_ccw_drop_indicator(vcdev, ccw);
 
 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
 		virtio_ccw_del_vq(vq, ccw);
@@ -326,6 +521,54 @@ out_err:
 	return ERR_PTR(err);
 }
 
+static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
+					   struct virtqueue *vqs[], int nvqs,
+					   struct ccw1 *ccw)
+{
+	int ret;
+	struct virtio_thinint_area *thinint_area = NULL;
+	struct airq_info *info;
+
+	thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
+	if (!thinint_area) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	/* Try to get an indicator. */
+	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
+						     &thinint_area->bit_nr,
+						     &vcdev->airq_info);
+	if (!thinint_area->indicator) {
+		ret = -ENOSPC;
+		goto out;
+	}
+	info = vcdev->airq_info;
+	thinint_area->summary_indicator =
+		(unsigned long) &info->summary_indicator;
+	thinint_area->isc = VIRTIO_AIRQ_ISC;
+	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
+	ccw->flags = CCW_FLAG_SLI;
+	ccw->count = sizeof(*thinint_area);
+	ccw->cda = (__u32)(unsigned long)thinint_area;
+	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
+	if (ret) {
+		if (ret == -EOPNOTSUPP) {
+			/*
+			 * The host does not support adapter interrupts
+			 * for virtio-ccw, stop trying.
+			 */
+			virtio_ccw_use_airq = 0;
+			pr_info("Adapter interrupts unsupported on host\n");
+		} else
+			dev_warn(&vcdev->cdev->dev,
+				 "enabling adapter interrupts = %d\n", ret);
+		virtio_ccw_drop_indicators(vcdev);
+	}
+out:
+	kfree(thinint_area);
+	return ret;
+}
+
 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 			       struct virtqueue *vqs[],
 			       vq_callback_t *callbacks[],
@@ -355,15 +598,23 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 	if (!indicatorp)
 		goto out;
 	*indicatorp = (unsigned long) &vcdev->indicators;
-	/* Register queue indicators with host. */
-	vcdev->indicators = 0;
-	ccw->cmd_code = CCW_CMD_SET_IND;
-	ccw->flags = 0;
-	ccw->count = sizeof(vcdev->indicators);
-	ccw->cda = (__u32)(unsigned long) indicatorp;
-	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
-	if (ret)
-		goto out;
+	if (vcdev->is_thinint) {
+		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
+		if (ret)
+			/* no error, just fall back to legacy interrupts */
+			vcdev->is_thinint = 0;
+	}
+	if (!vcdev->is_thinint) {
+		/* Register queue indicators with host. */
+		vcdev->indicators = 0;
+		ccw->cmd_code = CCW_CMD_SET_IND;
+		ccw->flags = 0;
+		ccw->count = sizeof(vcdev->indicators);
+		ccw->cda = (__u32)(unsigned long) indicatorp;
+		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
+		if (ret)
+			goto out;
+	}
 	/* Register indicators2 with host for config changes */
 	*indicatorp = (unsigned long) &vcdev->indicators2;
 	vcdev->indicators2 = 0;
@@ -636,6 +887,8 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev,
 	struct virtqueue *vq;
 	struct virtio_driver *drv;
 
+	if (!vcdev)
+		return;
 	/* Check if it's a notification from the host. */
 	if ((intparm == 0) &&
 	    (scsw_stctl(&irb->scsw) ==
@@ -663,6 +916,7 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev,
 		case VIRTIO_CCW_DOING_SET_CONF_IND:
 		case VIRTIO_CCW_DOING_RESET:
 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
+		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
 			vcdev->curr_io &= ~activity;
 			wake_up(&vcdev->wait_q);
 			break;
@@ -734,23 +988,37 @@ static int virtio_ccw_probe(struct ccw_device *cdev)
 	return 0;
 }
 
+static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
+{
+	unsigned long flags;
+	struct virtio_ccw_device *vcdev;
+
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+	vcdev = dev_get_drvdata(&cdev->dev);
+	if (!vcdev) {
+		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+		return NULL;
+	}
+	dev_set_drvdata(&cdev->dev, NULL);
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+	return vcdev;
+}
+
 static void virtio_ccw_remove(struct ccw_device *cdev)
 {
-	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
+	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
 
-	if (cdev->online) {
+	if (vcdev && cdev->online)
 		unregister_virtio_device(&vcdev->vdev);
-		dev_set_drvdata(&cdev->dev, NULL);
-	}
 	cdev->handler = NULL;
 }
 
 static int virtio_ccw_offline(struct ccw_device *cdev)
 {
-	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
+	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
 
-	unregister_virtio_device(&vcdev->vdev);
-	dev_set_drvdata(&cdev->dev, NULL);
+	if (vcdev)
+		unregister_virtio_device(&vcdev->vdev);
 	return 0;
 }
 
@@ -759,6 +1027,7 @@ static int virtio_ccw_online(struct ccw_device *cdev)
 {
 	int ret;
 	struct virtio_ccw_device *vcdev;
+	unsigned long flags;
 
 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
 	if (!vcdev) {
@@ -778,6 +1047,8 @@ static int virtio_ccw_online(struct ccw_device *cdev)
 		goto out_free;
 	}
 
+	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
+
 	vcdev->vdev.dev.parent = &cdev->dev;
 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
 	vcdev->vdev.config = &virtio_ccw_config_ops;
@@ -786,7 +1057,9 @@ static int virtio_ccw_online(struct ccw_device *cdev)
 	INIT_LIST_HEAD(&vcdev->virtqueues);
 	spin_lock_init(&vcdev->lock);
 
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
 	dev_set_drvdata(&cdev->dev, vcdev);
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
 	vcdev->vdev.id.vendor = cdev->id.cu_type;
 	vcdev->vdev.id.device = cdev->id.cu_model;
 	ret = register_virtio_device(&vcdev->vdev);
@@ -797,7 +1070,9 @@ static int virtio_ccw_online(struct ccw_device *cdev)
 	}
 	return 0;
 out_put:
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
 	dev_set_drvdata(&cdev->dev, NULL);
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
 	put_device(&vcdev->vdev.dev);
 	return ret;
 out_free:
@@ -935,6 +1210,10 @@ module_init(virtio_ccw_init);
 
 static void __exit virtio_ccw_exit(void)
 {
+	int i;
+
 	ccw_driver_unregister(&virtio_ccw_driver);
+	for (i = 0; i < MAX_AIRQ_AREAS; i++)
+		destroy_airq_info(airq_areas[i]);
 }
 module_exit(virtio_ccw_exit);