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authorStephen Neuendorffer <stephen.neuendorffer@xilinx.com>2010-11-18 15:55:02 -0800
committerGrant Likely <grant.likely@secretlab.ca>2010-12-29 17:02:15 -0700
commitfe14042358fac0673d4b6362a73796fd64379938 (patch)
tree7d2db09ee18157468c420909bef1be8e81d47b2f
parent57d00ecf90cc9854973da2960012b734acc26e51 (diff)
downloadop-kernel-dev-fe14042358fac0673d4b6362a73796fd64379938.zip
op-kernel-dev-fe14042358fac0673d4b6362a73796fd64379938.tar.gz
of/flattree: Refactor unflatten_device_tree and add fdt_unflatten_tree
unflatten_device_tree has two dependencies on things that happen during boot time. Firstly, it references the initial device tree directly. Secondly, it allocates memory using the early boot allocator. This patch factors out these dependencies and uses the new __unflatten_device_tree function to implement a driver-visible fdt_unflatten_tree function, which can be used to unflatten a blob after boot time. V2: - remove extra __va() call - make dt_alloc functions return void *. This doesn't fix the general strangeness in this code that constantly casts back and forth between unsigned long and __be32 * Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
-rw-r--r--drivers/of/fdt.c149
-rw-r--r--include/linux/of_fdt.h2
2 files changed, 100 insertions, 51 deletions
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 71edc9c..8a90ee4 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -11,10 +11,12 @@
#include <linux/kernel.h>
#include <linux/initrd.h>
+#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/string.h>
#include <linux/errno.h>
+#include <linux/slab.h>
#ifdef CONFIG_PPC
#include <asm/machdep.h>
@@ -312,6 +314,94 @@ unsigned long unflatten_dt_node(struct boot_param_header *blob,
return mem;
}
+/**
+ * __unflatten_device_tree - create tree of device_nodes from flat blob
+ *
+ * unflattens a device-tree, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ * @blob: The blob to expand
+ * @mynodes: The device_node tree created by the call
+ * @dt_alloc: An allocator that provides a virtual address to memory
+ * for the resulting tree
+ */
+void __unflatten_device_tree(struct boot_param_header *blob,
+ struct device_node **mynodes,
+ void * (*dt_alloc)(u64 size, u64 align))
+{
+ unsigned long start, mem, size;
+ struct device_node **allnextp = mynodes;
+
+ pr_debug(" -> unflatten_device_tree()\n");
+
+ if (!blob) {
+ pr_debug("No device tree pointer\n");
+ return;
+ }
+
+ pr_debug("Unflattening device tree:\n");
+ pr_debug("magic: %08x\n", be32_to_cpu(blob->magic));
+ pr_debug("size: %08x\n", be32_to_cpu(blob->totalsize));
+ pr_debug("version: %08x\n", be32_to_cpu(blob->version));
+
+ if (be32_to_cpu(blob->magic) != OF_DT_HEADER) {
+ pr_err("Invalid device tree blob header\n");
+ return;
+ }
+
+ /* First pass, scan for size */
+ start = ((unsigned long)blob) +
+ be32_to_cpu(blob->off_dt_struct);
+ size = unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
+ size = (size | 3) + 1;
+
+ pr_debug(" size is %lx, allocating...\n", size);
+
+ /* Allocate memory for the expanded device tree */
+ mem = (unsigned long)
+ dt_alloc(size + 4, __alignof__(struct device_node));
+
+ ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
+
+ pr_debug(" unflattening %lx...\n", mem);
+
+ /* Second pass, do actual unflattening */
+ start = ((unsigned long)blob) +
+ be32_to_cpu(blob->off_dt_struct);
+ unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
+ if (be32_to_cpup((__be32 *)start) != OF_DT_END)
+ pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
+ if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
+ pr_warning("End of tree marker overwritten: %08x\n",
+ be32_to_cpu(((__be32 *)mem)[size / 4]));
+ *allnextp = NULL;
+
+ pr_debug(" <- unflatten_device_tree()\n");
+}
+
+static void *kernel_tree_alloc(u64 size, u64 align)
+{
+ return kzalloc(size, GFP_KERNEL);
+}
+
+/**
+ * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
+ *
+ * unflattens the device-tree passed by the firmware, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ */
+void of_fdt_unflatten_tree(unsigned long *blob,
+ struct device_node **mynodes)
+{
+ struct boot_param_header *device_tree =
+ (struct boot_param_header *)blob;
+ __unflatten_device_tree(device_tree, mynodes, &kernel_tree_alloc);
+}
+EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
+
/* Everything below here references initial_boot_params directly. */
int __initdata dt_root_addr_cells;
int __initdata dt_root_size_cells;
@@ -569,6 +659,12 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
return 1;
}
+static void *__init early_device_tree_alloc(u64 size, u64 align)
+{
+ unsigned long mem = early_init_dt_alloc_memory_arch(size, align);
+ return __va(mem);
+}
+
/**
* unflatten_device_tree - create tree of device_nodes from flat blob
*
@@ -579,62 +675,13 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
*/
void __init unflatten_device_tree(void)
{
- unsigned long start, mem, size;
- struct device_node **allnextp = &allnodes;
-
- pr_debug(" -> unflatten_device_tree()\n");
-
- if (!initial_boot_params) {
- pr_debug("No device tree pointer\n");
- return;
- }
-
- pr_debug("Unflattening device tree:\n");
- pr_debug("magic: %08x\n", be32_to_cpu(initial_boot_params->magic));
- pr_debug("size: %08x\n", be32_to_cpu(initial_boot_params->totalsize));
- pr_debug("version: %08x\n", be32_to_cpu(initial_boot_params->version));
-
- if (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER) {
- pr_err("Invalid device tree blob header\n");
- return;
- }
-
- /* First pass, scan for size */
- start = ((unsigned long)initial_boot_params) +
- be32_to_cpu(initial_boot_params->off_dt_struct);
- size = unflatten_dt_node(initial_boot_params, 0, &start,
- NULL, NULL, 0);
- size = (size | 3) + 1;
-
- pr_debug(" size is %lx, allocating...\n", size);
-
- /* Allocate memory for the expanded device tree */
- mem = early_init_dt_alloc_memory_arch(size + 4,
- __alignof__(struct device_node));
- mem = (unsigned long) __va(mem);
-
- ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
-
- pr_debug(" unflattening %lx...\n", mem);
-
- /* Second pass, do actual unflattening */
- start = ((unsigned long)initial_boot_params) +
- be32_to_cpu(initial_boot_params->off_dt_struct);
- unflatten_dt_node(initial_boot_params, mem, &start,
- NULL, &allnextp, 0);
- if (be32_to_cpup((__be32 *)start) != OF_DT_END)
- pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
- if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
- pr_warning("End of tree marker overwritten: %08x\n",
- be32_to_cpu(((__be32 *)mem)[size / 4]));
- *allnextp = NULL;
+ __unflatten_device_tree(initial_boot_params, &allnodes,
+ early_device_tree_alloc);
/* Get pointer to OF "/chosen" node for use everywhere */
of_chosen = of_find_node_by_path("/chosen");
if (of_chosen == NULL)
of_chosen = of_find_node_by_path("/chosen@0");
-
- pr_debug(" <- unflatten_device_tree()\n");
}
#endif /* CONFIG_OF_EARLY_FLATTREE */
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index 70c5b73..9ce5dfd 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -68,6 +68,8 @@ extern void *of_fdt_get_property(struct boot_param_header *blob,
extern int of_fdt_is_compatible(struct boot_param_header *blob,
unsigned long node,
const char *compat);
+extern void of_fdt_unflatten_tree(unsigned long *blob,
+ struct device_node **mynodes);
/* TBD: Temporary export of fdt globals - remove when code fully merged */
extern int __initdata dt_root_addr_cells;
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