powerpc/BSR: Support multiple OF-node description of BSR

This adds support for multiple BSR nodes in the OF device tree.

Previously, the BSR driver only supported a single OF node describing
a BSR.  Apparently when an LPAR is set to use "all system resources"
the BSR appears as a single node, but when it is handed out in pieces,
each 8 byte piece gets its own node.  So, this keeps a list of BSR
devices instead of the array and includes all nodes.

Also, this makes the code be more inclusive of what BSR devices we
accept by only checking compatibility and not the device name property
(which might change in the future versions of BSR).

Signed-off-by: Sonny Rao <sonnyrao@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

drivers/char/bsr.c

@@ -60,15 +60,17 @@ struct bsr_dev {
 	unsigned bsr_num;      /* bsr id number for its type */
 	int      bsr_minor;
 
+	struct list_head bsr_list;
+
 	dev_t    bsr_dev;
 	struct cdev bsr_cdev;
 	struct device *bsr_device;
 	char     bsr_name[32];
 
 };
 
-static unsigned num_bsr_devs;
-static struct bsr_dev *bsr_devs;
+static unsigned total_bsr_devs;
+static struct list_head bsr_devs = LIST_HEAD_INIT(bsr_devs);
 static struct class *bsr_class;
 static int bsr_major;
 
@@ -146,60 +148,62 @@ const static struct file_operations bsr_fops = {
 
 static void bsr_cleanup_devs(void)
 {
-	int i;
-	for (i=0 ; i < num_bsr_devs; i++) {
-		struct bsr_dev *cur = bsr_devs + i;
+	struct bsr_dev *cur, *n;
+
+	list_for_each_entry_safe(cur, n, &bsr_devs, bsr_list) {
 		if (cur->bsr_device) {
 			cdev_del(&cur->bsr_cdev);
 			device_del(cur->bsr_device);
 		}
+		list_del(&cur->bsr_list);
+		kfree(cur);
 	}
-
-	kfree(bsr_devs);
 }
 
-static int bsr_create_devs(struct device_node *bn)
+static int bsr_add_node(struct device_node *bn)
 {
-	int bsr_stride_len, bsr_bytes_len;
+	int bsr_stride_len, bsr_bytes_len, num_bsr_devs;
 	const u32 *bsr_stride;
 	const u32 *bsr_bytes;
 	unsigned i;
+	int ret = -ENODEV;
 
 	bsr_stride = of_get_property(bn, "ibm,lock-stride", &bsr_stride_len);
 	bsr_bytes  = of_get_property(bn, "ibm,#lock-bytes", &bsr_bytes_len);
 
 	if (!bsr_stride || !bsr_bytes ||
 	    (bsr_stride_len != bsr_bytes_len)) {
 		printk(KERN_ERR "bsr of-node has missing/incorrect property\n");
-		return -ENODEV;
+		return ret;
 	}
 
 	num_bsr_devs = bsr_bytes_len / sizeof(u32);
 
-	/* only a warning, its informational since we'll fail and exit */
-	WARN_ON(num_bsr_devs > BSR_MAX_DEVS);
-
-	bsr_devs = kzalloc(sizeof(struct bsr_dev) * num_bsr_devs, GFP_KERNEL);
-	if (!bsr_devs)
-		return -ENOMEM;
-
 	for (i = 0 ; i < num_bsr_devs; i++) {
-		struct bsr_dev *cur = bsr_devs + i;
+		struct bsr_dev *cur = kzalloc(sizeof(struct bsr_dev),
+					      GFP_KERNEL);
 		struct resource res;
 		int result;
 
+		if (!cur) {
+			printk(KERN_ERR "Unable to alloc bsr dev\n");
+			ret = -ENOMEM;
+			goto out_err;
+		}
+
 		result = of_address_to_resource(bn, i, &res);
 		if (result < 0) {
-			printk(KERN_ERR "bsr of-node has invalid reg property\n");
-			goto out_err;
+			printk(KERN_ERR "bsr of-node has invalid reg property, skipping\n");
+			kfree(cur);
+			continue;
 		}
 
-		cur->bsr_minor  = i;
+		cur->bsr_minor  = i + total_bsr_devs;
 		cur->bsr_addr   = res.start;
 		cur->bsr_len    = res.end - res.start + 1;
 		cur->bsr_bytes  = bsr_bytes[i];
 		cur->bsr_stride = bsr_stride[i];
-		cur->bsr_dev    = MKDEV(bsr_major, i);
+		cur->bsr_dev    = MKDEV(bsr_major, i + total_bsr_devs);
 
 		switch(cur->bsr_bytes) {
 		case 8:
@@ -220,31 +224,53 @@ static int bsr_create_devs(struct device_node *bn)
 		}
 
 		cur->bsr_num = bsr_types[cur->bsr_type];
-		bsr_types[cur->bsr_type] = cur->bsr_num + 1;
 		snprintf(cur->bsr_name, 32, "bsr%d_%d",
 			 cur->bsr_bytes, cur->bsr_num);
 
 		cdev_init(&cur->bsr_cdev, &bsr_fops);
 		result = cdev_add(&cur->bsr_cdev, cur->bsr_dev, 1);
-		if (result)
+		if (result) {
+			kfree(cur);
 			goto out_err;
+		}
 
 		cur->bsr_device = device_create(bsr_class, NULL, cur->bsr_dev,
 						cur, cur->bsr_name);
 		if (!cur->bsr_device) {
 			printk(KERN_ERR "device_create failed for %s\n",
 			       cur->bsr_name);
 			cdev_del(&cur->bsr_cdev);
+			kfree(cur);
 			goto out_err;
 		}
+
+		bsr_types[cur->bsr_type] = cur->bsr_num + 1;
+		list_add_tail(&cur->bsr_list, &bsr_devs);
 	}
 
+	total_bsr_devs += num_bsr_devs;
+
 	return 0;
 
  out_err:
 
 	bsr_cleanup_devs();
-	return -ENODEV;
+	return ret;
+}
+
+static int bsr_create_devs(struct device_node *bn)
+{
+	int ret;
+
+	while (bn) {
+		ret = bsr_add_node(bn);
+		if (ret) {
+			of_node_put(bn);
+			return ret;
+		}
+		bn = of_find_compatible_node(bn, NULL, "ibm,bsr");
+	}
+	return 0;
 }
 
 static int __init bsr_init(void)
@@ -254,7 +280,7 @@ static int __init bsr_init(void)
 	int ret = -ENODEV;
 	int result;
 
-	np = of_find_compatible_node(NULL, "ibm,bsr", "ibm,bsr");
+	np = of_find_compatible_node(NULL, NULL, "ibm,bsr");
 	if (!np)
 		goto out_err;
 
@@ -272,10 +298,10 @@ static int __init bsr_init(void)
 		goto out_err_2;
 	}
 
-	if ((ret = bsr_create_devs(np)) < 0)
+	if ((ret = bsr_create_devs(np)) < 0) {
+		np = NULL;
 		goto out_err_3;
-
-	of_node_put(np);
+	}
 
 	return 0;