1 files changed, 318 insertions, 0 deletions
diff --git a/drivers/block/aoe/aoechr.c b/drivers/block/aoe/aoechr.c
new file mode 100644
index 000000000..8eea2529d
--- /dev/null
+++ b/drivers/block/aoe/aoechr.c
@@ -0,0 +1,318 @@
+/* Copyright (c) 2012 Coraid, Inc.  See COPYING for GPL terms. */
+/*
+ * aoechr.c
+ * AoE character device driver
+ */
+
+#include <linux/hdreg.h>
+#include <linux/blkdev.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include "aoe.h"
+
+enum {
+	//MINOR_STAT = 1, (moved to sysfs)
+	MINOR_ERR = 2,
+	MINOR_DISCOVER,
+	MINOR_INTERFACES,
+	MINOR_REVALIDATE,
+	MINOR_FLUSH,
+	MSGSZ = 2048,
+	NMSG = 100,		/* message backlog to retain */
+};
+
+struct aoe_chardev {
+	ulong minor;
+	char name[32];
+};
+
+enum { EMFL_VALID = 1 };
+
+struct ErrMsg {
+	short flags;
+	short len;
+	char *msg;
+};
+
+static DEFINE_MUTEX(aoechr_mutex);
+
+/* A ring buffer of error messages, to be read through
+ * "/dev/etherd/err".  When no messages are present,
+ * readers will block waiting for messages to appear.
+ */
+static struct ErrMsg emsgs[NMSG];
+static int emsgs_head_idx, emsgs_tail_idx;
+static struct completion emsgs_comp;
+static spinlock_t emsgs_lock;
+static int nblocked_emsgs_readers;
+static struct class *aoe_class;
+static struct aoe_chardev chardevs[] = {
+	{ MINOR_ERR, "err" },
+	{ MINOR_DISCOVER, "discover" },
+	{ MINOR_INTERFACES, "interfaces" },
+	{ MINOR_REVALIDATE, "revalidate" },
+	{ MINOR_FLUSH, "flush" },
+};
+
+static int
+discover(void)
+{
+	aoecmd_cfg(0xffff, 0xff);
+	return 0;
+}
+
+static int
+interfaces(const char __user *str, size_t size)
+{
+	if (set_aoe_iflist(str, size)) {
+		printk(KERN_ERR
+			"aoe: could not set interface list: too many interfaces\n");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int
+revalidate(const char __user *str, size_t size)
+{
+	int major, minor, n;
+	ulong flags;
+	struct aoedev *d;
+	struct sk_buff *skb;
+	char buf[16];
+
+	if (size >= sizeof buf)
+		return -EINVAL;
+	buf[sizeof buf - 1] = '\0';
+	if (copy_from_user(buf, str, size))
+		return -EFAULT;
+
+	n = sscanf(buf, "e%d.%d", &major, &minor);
+	if (n != 2) {
+		pr_err("aoe: invalid device specification %s\n", buf);
+		return -EINVAL;
+	}
+	d = aoedev_by_aoeaddr(major, minor, 0);
+	if (!d)
+		return -EINVAL;
+	spin_lock_irqsave(&d->lock, flags);
+	aoecmd_cleanslate(d);
+	aoecmd_cfg(major, minor);
+loop:
+	skb = aoecmd_ata_id(d);
+	spin_unlock_irqrestore(&d->lock, flags);
+	/* try again if we are able to sleep a bit,
+	 * otherwise give up this revalidation
+	 */
+	if (!skb && !msleep_interruptible(250)) {
+		spin_lock_irqsave(&d->lock, flags);
+		goto loop;
+	}
+	aoedev_put(d);
+	if (skb) {
+		struct sk_buff_head queue;
+		__skb_queue_head_init(&queue);
+		__skb_queue_tail(&queue, skb);
+		aoenet_xmit(&queue);
+	}
+	return 0;
+}
+
+void
+aoechr_error(char *msg)
+{
+	struct ErrMsg *em;
+	char *mp;
+	ulong flags, n;
+
+	n = strlen(msg);
+
+	spin_lock_irqsave(&emsgs_lock, flags);
+
+	em = emsgs + emsgs_tail_idx;
+	if ((em->flags & EMFL_VALID)) {
+bail:		spin_unlock_irqrestore(&emsgs_lock, flags);
+		return;
+	}
+
+	mp = kmemdup(msg, n, GFP_ATOMIC);
+	if (!mp)
+		goto bail;
+
+	em->msg = mp;
+	em->flags |= EMFL_VALID;
+	em->len = n;
+
+	emsgs_tail_idx++;
+	emsgs_tail_idx %= ARRAY_SIZE(emsgs);
+
+	spin_unlock_irqrestore(&emsgs_lock, flags);
+
+	if (nblocked_emsgs_readers)
+		complete(&emsgs_comp);
+}
+
+static ssize_t
+aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp)
+{
+	int ret = -EINVAL;
+
+	switch ((unsigned long) filp->private_data) {
+	default:
+		printk(KERN_INFO "aoe: can't write to that file.\n");
+		break;
+	case MINOR_DISCOVER:
+		ret = discover();
+		break;
+	case MINOR_INTERFACES:
+		ret = interfaces(buf, cnt);
+		break;
+	case MINOR_REVALIDATE:
+		ret = revalidate(buf, cnt);
+		break;
+	case MINOR_FLUSH:
+		ret = aoedev_flush(buf, cnt);
+		break;
+	}
+	if (ret == 0)
+		ret = cnt;
+	return ret;
+}
+
+static int
+aoechr_open(struct inode *inode, struct file *filp)
+{
+	int n, i;
+
+	mutex_lock(&aoechr_mutex);
+	n = iminor(inode);
+	filp->private_data = (void *) (unsigned long) n;
+
+	for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
+		if (chardevs[i].minor == n) {
+			mutex_unlock(&aoechr_mutex);
+			return 0;
+		}
+	mutex_unlock(&aoechr_mutex);
+	return -EINVAL;
+}
+
+static int
+aoechr_rel(struct inode *inode, struct file *filp)
+{
+	return 0;
+}
+
+static ssize_t
+aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off)
+{
+	unsigned long n;
+	char *mp;
+	struct ErrMsg *em;
+	ssize_t len;
+	ulong flags;
+
+	n = (unsigned long) filp->private_data;
+	if (n != MINOR_ERR)
+		return -EFAULT;
+
+	spin_lock_irqsave(&emsgs_lock, flags);
+
+	for (;;) {
+		em = emsgs + emsgs_head_idx;
+		if ((em->flags & EMFL_VALID) != 0)
+			break;
+		if (filp->f_flags & O_NDELAY) {
+			spin_unlock_irqrestore(&emsgs_lock, flags);
+			return -EAGAIN;
+		}
+		nblocked_emsgs_readers++;
+
+		spin_unlock_irqrestore(&emsgs_lock, flags);
+
+		n = wait_for_completion_interruptible(&emsgs_comp);
+
+		spin_lock_irqsave(&emsgs_lock, flags);
+
+		nblocked_emsgs_readers--;
+
+		if (n) {
+			spin_unlock_irqrestore(&emsgs_lock, flags);
+			return -ERESTARTSYS;
+		}
+	}
+	if (em->len > cnt) {
+		spin_unlock_irqrestore(&emsgs_lock, flags);
+		return -EAGAIN;
+	}
+	mp = em->msg;
+	len = em->len;
+	em->msg = NULL;
+	em->flags &= ~EMFL_VALID;
+
+	emsgs_head_idx++;
+	emsgs_head_idx %= ARRAY_SIZE(emsgs);
+
+	spin_unlock_irqrestore(&emsgs_lock, flags);
+
+	n = copy_to_user(buf, mp, len);
+	kfree(mp);
+	return n == 0 ? len : -EFAULT;
+}
+
+static const struct file_operations aoe_fops = {
+	.write = aoechr_write,
+	.read = aoechr_read,
+	.open = aoechr_open,
+	.release = aoechr_rel,
+	.owner = THIS_MODULE,
+	.llseek = noop_llseek,
+};
+
+static char *aoe_devnode(struct device *dev, umode_t *mode)
+{
+	return kasprintf(GFP_KERNEL, "etherd/%s", dev_name(dev));
+}
+
+int __init
+aoechr_init(void)
+{
+	int n, i;
+
+	n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops);
+	if (n < 0) {
+		printk(KERN_ERR "aoe: can't register char device\n");
+		return n;
+	}
+	init_completion(&emsgs_comp);
+	spin_lock_init(&emsgs_lock);
+	aoe_class = class_create(THIS_MODULE, "aoe");
+	if (IS_ERR(aoe_class)) {
+		unregister_chrdev(AOE_MAJOR, "aoechr");
+		return PTR_ERR(aoe_class);
+	}
+	aoe_class->devnode = aoe_devnode;
+
+	for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
+		device_create(aoe_class, NULL,
+			      MKDEV(AOE_MAJOR, chardevs[i].minor), NULL,
+			      chardevs[i].name);
+
+	return 0;
+}
+
+void
+aoechr_exit(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
+		device_destroy(aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor));
+	class_destroy(aoe_class);
+	unregister_chrdev(AOE_MAJOR, "aoechr");
+}
+