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drivers/of: Split unflatten_dt_node() 

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@linux.vnet.ibm.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
This commit is contained in:
Gavin Shan 2016-05-03 23:22:47 +10:00 committed by Rob Herring
parent 011d6f5c3e
commit dfbd4c6eff
1 changed files with 147 additions and 102 deletions
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249
drivers/of/fdt.c
View File

@ -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)