The function unflatten_dt_node() is called recursively to unflatten
device nodes and properties in the FDT blob. It looks complicated
and hard to be understood.
This splits the function into 3 functions: populate_properties(),
populate_node() and unflatten_dt_node(). populate_properties(),
which is called by populate_node(), creates properties for the
indicated device node. The later one creates the device nodes
from FDT blob. populate_node() gets the offset in FDT blob for
next device nodes and then calls populate_node(). No logical
changes introduced.
Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
---
drivers/of/fdt.c | 249 ++++++++++++++++++++++++++++++++-----------------------
1 file changed, 147 insertions(+), 102 deletions(-)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 655f79d..3c69002 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -161,39 +161,127 @@ static void *unflatten_dt_alloc(void **mem, unsigned long size,
return res;
}
-/**
- * unflatten_dt_node - Alloc and populate a device_node from the flat tree
- * @blob: The parent device tree blob
- * @mem: Memory chunk to use for allocating device nodes and properties
- * @poffset: pointer to node in flat tree
- * @dad: Parent struct device_node
- * @nodepp: The device_node tree created by the call
- * @fpsize: Size of the node path up at the current depth.
- * @dryrun: If true, do not allocate device nodes but still calculate needed
- * memory size
- */
-static void * unflatten_dt_node(const void *blob,
- void *mem,
- int *poffset,
- struct device_node *dad,
- struct device_node **nodepp,
- unsigned long fpsize,
+static void populate_properties(const void *blob,
+ int offset,
+ void **mem,
+ struct device_node *np,
+ const char *nodename,
bool dryrun)
{
- const __be32 *p;
+ struct property *pp, **pprev = NULL;
+ int cur;
+ bool has_name = false;
+
+ pprev = &np->properties;
+ for (cur = fdt_first_property_offset(blob, offset);
+ cur >= 0;
+ cur = fdt_next_property_offset(blob, cur)) {
+ const __be32 *val;
+ const char *pname;
+ u32 sz;
+
+ val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
+ if (!val) {
+ pr_warn("%s: Cannot locate property at 0x%x\n",
+ __func__, cur);
+ continue;
+ }
+
+ if (!pname) {
+ pr_warn("%s: Cannot find property name at 0x%x\n",
+ __func__, cur);
+ continue;
+ }
+
+ if (!strcmp(pname, "name"))
+ has_name = true;
+
+ pp = unflatten_dt_alloc(mem, sizeof(struct property),
+ __alignof__(struct property));
+ if (dryrun)
+ continue;
+
+ /* We accept flattened tree phandles either in
+ * ePAPR-style "phandle" properties, or the
+ * legacy "linux,phandle" properties. If both
+ * appear and have different values, things
+ * will get weird. Don't do that.
+ */
+ if (!strcmp(pname, "phandle") ||
+ !strcmp(pname, "linux,phandle")) {
+ if (!np->phandle)
+ np->phandle = be32_to_cpup(val);
+ }
+
+ /* And we process the "ibm,phandle" property
+ * used in pSeries dynamic device tree
+ * stuff
+ */
+ if (!strcmp(pname, "ibm,phandle"))
+ np->phandle = be32_to_cpup(val);
+
+ pp->name = (char *)pname;
+ pp->length = sz;
+ pp->value = (__be32 *)val;
+ *pprev = pp;
+ pprev = &pp->next;
+ }
+
+ /* With version 0x10 we may not have the name property,
+ * recreate it here from the unit name if absent
+ */
+ if (!has_name) {
+ const char *p = nodename, *ps = p, *pa = NULL;
+ int len;
+
+ while (*p) {
+ if ((*p) == '@')
+ pa = p;
+ else if ((*p) == '/')
+ ps = p + 1;
+ p++;
+ }
+
+ if (pa < ps)
+ pa = p;
+ len = (pa - ps) + 1;
+ pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
+ __alignof__(struct property));
+ if (!dryrun) {
+ pp->name = "name";
+ pp->length = len;
+ pp->value = pp + 1;
+ *pprev = pp;
+ pprev = &pp->next;
+ memcpy(pp->value, ps, len - 1);
+ ((char *)pp->value)[len - 1] = 0;
+ pr_debug("fixed up name for %s -> %s\n",
+ nodename, (char *)pp->value);
+ }
+ }
+
+ if (!dryrun)
+ *pprev = NULL;
+}
+
+static unsigned long populate_node(const void *blob,
+ int offset,
+ void **mem,
+ struct device_node *dad,
+ unsigned long fpsize,
+ struct device_node **pnp,
+ bool dryrun)
+{
struct device_node *np;
- struct property *pp, **prev_pp = NULL;
const char *pathp;
unsigned int l, allocl;
- static int depth;
- int old_depth;
- int offset;
- int has_name = 0;
int new_format = 0;
- pathp = fdt_get_name(blob, *poffset, &l);
- if (!pathp)
- return mem;
+ pathp = fdt_get_name(blob, offset, &l);
+ if (!pathp) {
+ *pnp = NULL;
+ return 0;
+ }
allocl = ++l;
@@ -223,7 +311,7 @@ static void * unflatten_dt_node(const void *blob,
}
}
- np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
+ np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl,
__alignof__(struct device_node));
if (!dryrun) {
char *fn;
@@ -246,89 +334,15 @@ static void * unflatten_dt_node(const void *blob,
}
memcpy(fn, pathp, l);
- prev_pp = &np->properties;
if (dad != NULL) {
np->parent = dad;
np->sibling = dad->child;
dad->child = np;
}
}
- /* process properties */
- for (offset = fdt_first_property_offset(blob, *poffset);
- (offset >= 0);
- (offset = fdt_next_property_offset(blob, offset))) {
- const char *pname;
- u32 sz;
- if (!(p = fdt_getprop_by_offset(blob, offset, &pname, &sz))) {
- offset = -FDT_ERR_INTERNAL;
- break;
- }
-
- if (pname == NULL) {
- pr_info("Can't find property name in list !\n");
- break;
- }
- if (strcmp(pname, "name") == 0)
- has_name = 1;
- pp = unflatten_dt_alloc(&mem, sizeof(struct property),
- __alignof__(struct property));
- if (!dryrun) {
- /* We accept flattened tree phandles either in
- * ePAPR-style "phandle" properties, or the
- * legacy "linux,phandle" properties. If both
- * appear and have different values, things
- * will get weird. Don't do that. */
- if ((strcmp(pname, "phandle") == 0) ||
- (strcmp(pname, "linux,phandle") == 0)) {
- if (np->phandle == 0)
- np->phandle = be32_to_cpup(p);
- }
- /* And we process the "ibm,phandle" property
- * used in pSeries dynamic device tree
- * stuff */
- if (strcmp(pname, "ibm,phandle") == 0)
- np->phandle = be32_to_cpup(p);
- pp->name = (char *)pname;
- pp->length = sz;
- pp->value = (__be32 *)p;
- *prev_pp = pp;
- prev_pp = &pp->next;
- }
- }
- /* with version 0x10 we may not have the name property, recreate
- * it here from the unit name if absent
- */
- if (!has_name) {
- const char *p1 = pathp, *ps = pathp, *pa = NULL;
- int sz;
-
- while (*p1) {
- if ((*p1) == '@')
- pa = p1;
- if ((*p1) == '/')
- ps = p1 + 1;
- p1++;
- }
- if (pa < ps)
- pa = p1;
- sz = (pa - ps) + 1;
- pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
- __alignof__(struct property));
- if (!dryrun) {
- pp->name = "name";
- pp->length = sz;
- pp->value = pp + 1;
- *prev_pp = pp;
- prev_pp = &pp->next;
- memcpy(pp->value, ps, sz - 1);
- ((char *)pp->value)[sz - 1] = 0;
- pr_debug("fixed up name for %s -> %s\n", pathp,
- (char *)pp->value);
- }
- }
+ populate_properties(blob, offset, mem, np, pathp, dryrun);
if (!dryrun) {
- *prev_pp = NULL;
np->name = of_get_property(np, "name", NULL);
np->type = of_get_property(np, "device_type", NULL);
@@ -338,6 +352,37 @@ static void * unflatten_dt_node(const void *blob,
np->type = "<NULL>";
}
+ *pnp = np;
+ return fpsize;
+}
+
+/**
+ * unflatten_dt_node - Alloc and populate a device_node from the flat tree
+ * @blob: The parent device tree blob
+ * @mem: Memory chunk to use for allocating device nodes and properties
+ * @poffset: pointer to node in flat tree
+ * @dad: Parent struct device_node
+ * @nodepp: The device_node tree created by the call
+ * @fpsize: Size of the node path up at the current depth.
+ * @dryrun: If true, do not allocate device nodes but still calculate needed
+ * memory size
+ */
+static void *unflatten_dt_node(const void *blob,
+ void *mem,
+ int *poffset,
+ struct device_node *dad,
+ struct device_node **nodepp,
+ unsigned long fpsize,
+ bool dryrun)
+{
+ struct device_node *np;
+ static int depth;
+ int old_depth;
+
+ fpsize = populate_node(blob, *poffset, &mem, dad, fpsize, &np, dryrun);
+ if (!fpsize)
+ return mem;
+
old_depth = depth;
*poffset = fdt_next_node(blob, *poffset, &depth);
if (depth < 0)
--
2.1.0
--
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