[PATCH] of/fdt: Add unflatten_partial_device_tree
Stephen Neuendorffer
stephen.neuendorffer at xilinx.com
Tue Jun 29 03:47:57 EST 2010
This code allows a user to parse a partial device tree blob, which is
structurally independent of any toplevel blob.
Previously, this code assumed that the blob comes from initial_boot_params.
Now, unflatten_partial_device_tree can take a blob from an arbitrary position,
and the location of the blob gets passed around to the various support functions.
Some of the functions are still tied to the initial_boot_params blob, although
perhaps they should get abstracted as well?
---
drivers/of/fdt.c | 147 ++++++++++++++++++++++++++++++++++++------------
include/linux/of_fdt.h | 10 ++-
2 files changed, 118 insertions(+), 39 deletions(-)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 66401bc..628ba4f 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>
@@ -22,15 +24,16 @@
#include <asm/page.h>
-int __initdata dt_root_addr_cells;
-int __initdata dt_root_size_cells;
+int dt_root_addr_cells;
+int dt_root_size_cells;
struct boot_param_header *initial_boot_params;
-char *find_flat_dt_string(u32 offset)
+char *find_flat_dt_string(u32 offset,
+ struct boot_param_header *blob)
{
- return ((char *)initial_boot_params) +
- be32_to_cpu(initial_boot_params->off_dt_strings) + offset;
+ return ((char *)blob) +
+ be32_to_cpu(blob->off_dt_strings) + offset;
}
/**
@@ -42,7 +45,7 @@ char *find_flat_dt_string(u32 offset)
* used to extract the memory information at boot before we can
* unflatten the tree
*/
-int __init of_scan_flat_dt(int (*it)(unsigned long node,
+int of_scan_flat_dt(int (*it)(unsigned long node,
const char *uname, int depth,
void *data),
void *data)
@@ -102,7 +105,7 @@ int __init of_scan_flat_dt(int (*it)(unsigned long node,
/**
* of_get_flat_dt_root - find the root node in the flat blob
*/
-unsigned long __init of_get_flat_dt_root(void)
+unsigned long of_get_flat_dt_root(void)
{
unsigned long p = ((unsigned long)initial_boot_params) +
be32_to_cpu(initial_boot_params->off_dt_struct);
@@ -120,8 +123,9 @@ unsigned long __init of_get_flat_dt_root(void)
* This function can be used within scan_flattened_dt callback to get
* access to properties
*/
-void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
- unsigned long *size)
+void * of_get_flat_dt_prop(unsigned long node, const char *name,
+ unsigned long *size,
+ struct boot_param_header *blob)
{
unsigned long p = node;
@@ -142,7 +146,7 @@ void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
if (be32_to_cpu(initial_boot_params->version) < 0x10)
p = ALIGN(p, sz >= 8 ? 8 : 4);
- nstr = find_flat_dt_string(noff);
+ nstr = find_flat_dt_string(noff, blob);
if (nstr == NULL) {
pr_warning("Can't find property index name !\n");
return NULL;
@@ -162,12 +166,13 @@ void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
* @node: node to test
* @compat: compatible string to compare with compatible list.
*/
-int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
+int of_flat_dt_is_compatible(unsigned long node, const char *compat,
+ struct boot_param_header *blob)
{
const char *cp;
unsigned long cplen, l;
- cp = of_get_flat_dt_prop(node, "compatible", &cplen);
+ cp = of_get_flat_dt_prop(node, "compatible", &cplen, blob);
if (cp == NULL)
return 0;
while (cplen > 0) {
@@ -181,7 +186,7 @@ int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
return 0;
}
-static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
+static void * unflatten_dt_alloc(unsigned long *mem, unsigned long size,
unsigned long align)
{
void *res;
@@ -200,11 +205,12 @@ static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
* @allnextpp: pointer to ->allnext from last allocated device_node
* @fpsize: Size of the node path up at the current depth.
*/
-unsigned long __init unflatten_dt_node(unsigned long mem,
+unsigned long unflatten_dt_node(unsigned long mem,
unsigned long *p,
struct device_node *dad,
struct device_node ***allnextpp,
- unsigned long fpsize)
+ unsigned long fpsize,
+ struct boot_param_header *blob)
{
struct device_node *np;
struct property *pp, **prev_pp = NULL;
@@ -300,10 +306,10 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
sz = be32_to_cpup((__be32 *)(*p));
noff = be32_to_cpup((__be32 *)((*p) + 4));
*p += 8;
- if (be32_to_cpu(initial_boot_params->version) < 0x10)
+ if (be32_to_cpu(blob->version) < 0x10)
*p = ALIGN(*p, sz >= 8 ? 8 : 4);
- pname = find_flat_dt_string(noff);
+ pname = find_flat_dt_string(noff, blob);
if (pname == NULL) {
pr_info("Can't find property name in list !\n");
break;
@@ -382,7 +388,7 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
if (tag == OF_DT_NOP)
*p += 4;
else
- mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
+ mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize, blob);
tag = be32_to_cpup((__be32 *)(*p));
}
if (tag != OF_DT_END_NODE) {
@@ -393,24 +399,26 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
return mem;
}
+#if defined(CONFIG_MICROBLAZE) || defined(CONFIG_POWERPC) || defined(CONFIG_SPARC)
+
#ifdef CONFIG_BLK_DEV_INITRD
/**
* early_init_dt_check_for_initrd - Decode initrd location from flat tree
* @node: reference to node containing initrd location ('chosen')
*/
-void __init early_init_dt_check_for_initrd(unsigned long node)
+void early_init_dt_check_for_initrd(unsigned long node)
{
unsigned long start, end, len;
__be32 *prop;
pr_debug("Looking for initrd properties... ");
- prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
+ prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len, initial_boot_params);
if (!prop)
return;
start = of_read_ulong(prop, len/4);
- prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
+ prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len, initial_boot_params);
if (!prop)
return;
end = of_read_ulong(prop, len/4);
@@ -427,7 +435,7 @@ inline void early_init_dt_check_for_initrd(unsigned long node)
/**
* early_init_dt_scan_root - fetch the top level address and size cells
*/
-int __init early_init_dt_scan_root(unsigned long node, const char *uname,
+int early_init_dt_scan_root(unsigned long node, const char *uname,
int depth, void *data)
{
__be32 *prop;
@@ -438,12 +446,12 @@ int __init early_init_dt_scan_root(unsigned long node, const char *uname,
dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
- prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
+ prop = of_get_flat_dt_prop(node, "#size-cells", NULL, initial_boot_params);
if (prop)
dt_root_size_cells = be32_to_cpup(prop);
pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
- prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
+ prop = of_get_flat_dt_prop(node, "#address-cells", NULL, initial_boot_params);
if (prop)
dt_root_addr_cells = be32_to_cpup(prop);
pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
@@ -452,7 +460,7 @@ int __init early_init_dt_scan_root(unsigned long node, const char *uname,
return 1;
}
-u64 __init dt_mem_next_cell(int s, __be32 **cellp)
+u64 dt_mem_next_cell(int s, __be32 **cellp)
{
__be32 *p = *cellp;
@@ -463,10 +471,10 @@ u64 __init dt_mem_next_cell(int s, __be32 **cellp)
/**
* early_init_dt_scan_memory - Look for an parse memory nodes
*/
-int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
+int early_init_dt_scan_memory(unsigned long node, const char *uname,
int depth, void *data)
{
- char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+ char *type = of_get_flat_dt_prop(node, "device_type", NULL, initial_boot_params);
__be32 *reg, *endp;
unsigned long l;
@@ -481,9 +489,9 @@ int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
} else if (strcmp(type, "memory") != 0)
return 0;
- reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
+ reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l, initial_boot_params);
if (reg == NULL)
- reg = of_get_flat_dt_prop(node, "reg", &l);
+ reg = of_get_flat_dt_prop(node, "reg", &l, initial_boot_params);
if (reg == NULL)
return 0;
@@ -509,7 +517,7 @@ int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
return 0;
}
-int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
+int early_init_dt_scan_chosen(unsigned long node, const char *uname,
int depth, void *data)
{
unsigned long l;
@@ -523,12 +531,12 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
early_init_dt_check_for_initrd(node);
+#ifdef CONFIG_CMDLINE
/* Retreive command line */
- p = of_get_flat_dt_prop(node, "bootargs", &l);
+ p = of_get_flat_dt_prop(node, "bootargs", &l, initial_boot_params);
if (p != NULL && l > 0)
strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE));
-#ifdef CONFIG_CMDLINE
#ifndef CONFIG_CMDLINE_FORCE
if (p == NULL || l == 0 || (l == 1 && (*p) == 0))
#endif
@@ -537,12 +545,14 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
early_init_dt_scan_chosen_arch(node);
+#ifdef CONFIG_CMDLINE
pr_debug("Command line is: %s\n", cmd_line);
+#endif /* CONFIG_CMDLINE */
/* break now */
return 1;
}
-
+
/**
* unflatten_device_tree - create tree of device_nodes from flat blob
*
@@ -551,7 +561,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
* pointers of the nodes so the normal device-tree walking functions
* can be used.
*/
-void __init unflatten_device_tree(void)
+void unflatten_device_tree(void)
{
unsigned long start, mem, size;
struct device_node **allnextp = &allnodes;
@@ -576,7 +586,7 @@ void __init unflatten_device_tree(void)
/* First pass, scan for size */
start = ((unsigned long)initial_boot_params) +
be32_to_cpu(initial_boot_params->off_dt_struct);
- size = unflatten_dt_node(0, &start, NULL, NULL, 0);
+ size = unflatten_dt_node(0, &start, NULL, NULL, 0, initial_boot_params);
size = (size | 3) + 1;
pr_debug(" size is %lx, allocating...\n", size);
@@ -593,7 +603,7 @@ void __init unflatten_device_tree(void)
/* Second pass, do actual unflattening */
start = ((unsigned long)initial_boot_params) +
be32_to_cpu(initial_boot_params->off_dt_struct);
- unflatten_dt_node(mem, &start, NULL, &allnextp, 0);
+ unflatten_dt_node(mem, &start, NULL, &allnextp, 0, initial_boot_params);
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)
@@ -608,3 +618,68 @@ void __init unflatten_device_tree(void)
pr_debug(" <- unflatten_device_tree()\n");
}
+
+#endif
+
+/**
+ * unflatten_partial_device_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 unflatten_partial_device_tree(unsigned long *blob, struct device_node **mynodes)
+{
+ struct boot_param_header *device_tree = (struct boot_param_header *)blob;
+ unsigned long start, mem, size;
+ struct device_node **allnextp = mynodes;
+
+ pr_debug(" -> unflatten_partial_device_tree()\n");
+
+ if (!device_tree) {
+ pr_debug("No device tree pointer\n");
+ return;
+ }
+
+ pr_debug("Unflattening device tree:\n");
+ pr_debug("magic: %08x\n", be32_to_cpu(device_tree->magic));
+ pr_debug("size: %08x\n", be32_to_cpu(device_tree->totalsize));
+ pr_debug("version: %08x\n", be32_to_cpu(device_tree->version));
+
+ if (be32_to_cpu(device_tree->magic) != OF_DT_HEADER) {
+ pr_err("Invalid device tree blob header %x \n", be32_to_cpu(device_tree->magic));
+ return;
+ }
+
+ /* First pass, scan for size */
+ start = ((unsigned long)device_tree) +
+ be32_to_cpu(device_tree->off_dt_struct);
+ size = unflatten_dt_node(0, &start, NULL, NULL, 0, device_tree);
+ size = (size | 3) + 1;
+
+ pr_debug(" size is %lx, allocating...\n", size);
+
+ /* Allocate memory for the expanded device tree */
+ mem = (unsigned long) kzalloc(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)device_tree) +
+ be32_to_cpu(device_tree->off_dt_struct);
+ unflatten_dt_node(mem, &start, NULL, &allnextp, 0, device_tree);
+ 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_partial_device_tree()\n");
+}
+
+EXPORT_SYMBOL(unflatten_partial_device_tree);
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index 71e1a91..008f520 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -64,13 +64,16 @@ extern int __initdata dt_root_size_cells;
extern struct boot_param_header *initial_boot_params;
/* For scanning the flat device-tree at boot time */
-extern char *find_flat_dt_string(u32 offset);
+extern char *find_flat_dt_string(u32 offset,
+ struct boot_param_header *blob);
extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname,
int depth, void *data),
void *data);
extern void *of_get_flat_dt_prop(unsigned long node, const char *name,
- unsigned long *size);
-extern int of_flat_dt_is_compatible(unsigned long node, const char *name);
+ unsigned long *size,
+ struct boot_param_header *blob);
+extern int of_flat_dt_is_compatible(unsigned long node, const char *name,
+ struct boot_param_header *blob);
extern unsigned long of_get_flat_dt_root(void);
extern void early_init_dt_scan_chosen_arch(unsigned long node);
extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
@@ -98,6 +101,7 @@ extern int early_init_dt_scan_root(unsigned long node, const char *uname,
/* Other Prototypes */
extern void unflatten_device_tree(void);
+extern void unflatten_partial_device_tree(unsigned long *blob, struct device_node **mynodes);
extern void early_init_devtree(void *);
#else /* CONFIG_OF_FLATTREE */
static inline void unflatten_device_tree(void) {}
--
1.5.6.6
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