Merge branch 'for-v3.12' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping

Pull DMA mapping update from Marek Szyprowski:
 "This contains an addition of Device Tree support for reserved memory
  regions (Contiguous Memory Allocator is one of the drivers for it) and
  changes required by the KVM extensions for PowerPC architectue"

* 'for-v3.12' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
  ARM: init: add support for reserved memory defined by device tree
  drivers: of: add initialization code for dma reserved memory
  drivers: of: add function to scan fdt nodes given by path
  drivers: dma-contiguous: clean source code and prepare for device tree

1 files changed, 76 insertions, 0 deletions

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index b10ba00..4fb06f3 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -545,6 +545,82 @@ int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 	return of_fdt_match(initial_boot_params, node, compat);
 }
 
+struct fdt_scan_status {
+	const char *name;
+	int namelen;
+	int depth;
+	int found;
+	int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
+	void *data;
+};
+
+/**
+ * fdt_scan_node_by_path - iterator for of_scan_flat_dt_by_path function
+ */
+static int __init fdt_scan_node_by_path(unsigned long node, const char *uname,
+					int depth, void *data)
+{
+	struct fdt_scan_status *st = data;
+
+	/*
+	 * if scan at the requested fdt node has been completed,
+	 * return -ENXIO to abort further scanning
+	 */
+	if (depth <= st->depth)
+		return -ENXIO;
+
+	/* requested fdt node has been found, so call iterator function */
+	if (st->found)
+		return st->iterator(node, uname, depth, st->data);
+
+	/* check if scanning automata is entering next level of fdt nodes */
+	if (depth == st->depth + 1 &&
+	    strncmp(st->name, uname, st->namelen) == 0 &&
+	    uname[st->namelen] == 0) {
+		st->depth += 1;
+		if (st->name[st->namelen] == 0) {
+			st->found = 1;
+		} else {
+			const char *next = st->name + st->namelen + 1;
+			st->name = next;
+			st->namelen = strcspn(next, "/");
+		}
+		return 0;
+	}
+
+	/* scan next fdt node */
+	return 0;
+}
+
+/**
+ * of_scan_flat_dt_by_path - scan flattened tree blob and call callback on each
+ *			     child of the given path.
+ * @path: path to start searching for children
+ * @it: callback function
+ * @data: context data pointer
+ *
+ * This function is used to scan the flattened device-tree starting from the
+ * node given by path. It is used to extract information (like reserved
+ * memory), which is required on ealy boot before we can unflatten the tree.
+ */
+int __init of_scan_flat_dt_by_path(const char *path,
+	int (*it)(unsigned long node, const char *name, int depth, void *data),
+	void *data)
+{
+	struct fdt_scan_status st = {path, 0, -1, 0, it, data};
+	int ret = 0;
+
+	if (initial_boot_params)
+                ret = of_scan_flat_dt(fdt_scan_node_by_path, &st);
+
+	if (!st.found)
+		return -ENOENT;
+	else if (ret == -ENXIO)	/* scan has been completed */
+		return 0;
+	else
+		return ret;
+}
+
 #ifdef CONFIG_BLK_DEV_INITRD
 /**
  * early_init_dt_check_for_initrd - Decode initrd location from flat tree