hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

[PATCH] ppc32/ppc64: cleanup /proc/device-tree 

This cleans up the /proc/device-tree representation of the Open Firmware
device-tree on ppc and ppc64.  It does the following things:

 - Workaround an issue in some Apple device-trees where a property may
   exist with the same name as a child node of the parent.  We now
   simply "drop" the property instead of creating duplicate entries in
   /proc with random result...

 - Do not try to chop off the "@0" at the end of a node name whose unit
   address is 0.  This is not useful, inconsistent, and the code was
   buggy and didn't always work anyway.

 - Do not create symlinks for the short name and unit address parts of a
   node.  These were never really used, bloated the memory footprint of
   the device-tree with useless struct proc_dir_entry and their matching
   dentry and inode cache bloat.

This results in smaller code, smaller memory footprint, and a more
accurate view of the tree presented to userland.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Benjamin Herrenschmidt 2005-06-01 17:07:27 +10:00 committed by Linus Torvalds
parent f93ea23498
commit 5f64f73957
3 changed files with 44 additions and 92 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
arch/ppc64/kernel/pSeries_reconfig.c
View File

@ -47,14 +47,6 @@ static void remove_node_proc_entries(struct device_node *np)
remove_proc_entry(pp->name, np->pde);
pp = pp->next;
}
/* Assuming that symlinks have the same parent directory as
* np->pde.
*/
if (np->name_link)
remove_proc_entry(np->name_link->name, parent->pde);
if (np->addr_link)
remove_proc_entry(np->addr_link->name, parent->pde);
if (np->pde)
remove_proc_entry(np->pde->name, parent->pde);
}

115
fs/proc/proc_devtree.c
View File

@ -12,15 +12,8 @@
#include <asm/uaccess.h>
#ifndef HAVE_ARCH_DEVTREE_FIXUPS
static inline void set_node_proc_entry(struct device_node *np, struct proc_dir_entry *de)
{
}
static void inline set_node_name_link(struct device_node *np, struct proc_dir_entry *de)
{
}
static void inline set_node_addr_link(struct device_node *np, struct proc_dir_entry *de)
static inline void set_node_proc_entry(struct device_node *np,
struct proc_dir_entry *de)
{
}
#endif
@ -58,89 +51,67 @@ static int property_read_proc(char *page, char **start, off_t off,
/*
* Process a node, adding entries for its children and its properties.
*/
void proc_device_tree_add_node(struct device_node *np, struct proc_dir_entry *de)
void proc_device_tree_add_node(struct device_node *np,
struct proc_dir_entry *de)
{
struct property *pp;
struct proc_dir_entry *ent;
struct device_node *child, *sib;
const char *p, *at;
int l;
struct proc_dir_entry *list, **lastp, *al;
struct device_node *child;
struct proc_dir_entry *list = NULL, **lastp;
const char *p;
set_node_proc_entry(np, de);
lastp = &list;
for (child = NULL; (child = of_get_next_child(np, child));) {
p = strrchr(child->full_name, '/');
if (!p)
p = child->full_name;
else
++p;
ent = proc_mkdir(p, de);
if (ent == 0)
break;
*lastp = ent;
ent->next = NULL;
lastp = &ent->next;
proc_device_tree_add_node(child, ent);
}
of_node_put(child);
for (pp = np->properties; pp != 0; pp = pp->next) {
/*
* Yet another Apple device-tree bogosity: on some machines,
* they have properties & nodes with the same name. Those
* properties are quite unimportant for us though, thus we
* simply "skip" them here, but we do have to check.
*/
for (ent = list; ent != NULL; ent = ent->next)
if (!strcmp(ent->name, pp->name))
break;
if (ent != NULL) {
printk(KERN_WARNING "device-tree: property \"%s\" name"
" conflicts with node in %s\n", pp->name,
np->full_name);
continue;
}
/*
* Unfortunately proc_register puts each new entry
* at the beginning of the list. So we rearrange them.
*/
ent = create_proc_read_entry(pp->name, strncmp(pp->name, "security-", 9) ?
S_IRUGO : S_IRUSR, de, property_read_proc, pp);
ent = create_proc_read_entry(pp->name,
strncmp(pp->name, "security-", 9)
? S_IRUGO : S_IRUSR, de,
property_read_proc, pp);
if (ent == 0)
break;
if (!strncmp(pp->name, "security-", 9))
ent->size = 0; /* don't leak number of password chars */
else
ent->size = pp->length;
ent->next = NULL;
*lastp = ent;
lastp = &ent->next;
}
child = NULL;
while ((child = of_get_next_child(np, child))) {
p = strrchr(child->full_name, '/');
if (!p)
p = child->full_name;
else
++p;
/* chop off '@0' if the name ends with that */
l = strlen(p);
if (l > 2 && p[l-2] == '@' && p[l-1] == '0')
l -= 2;
ent = proc_mkdir(p, de);
if (ent == 0)
break;
*lastp = ent;
lastp = &ent->next;
proc_device_tree_add_node(child, ent);
/*
* If we left the address part on the name, consider
* adding symlinks from the name and address parts.
*/
if (p[l] != 0 || (at = strchr(p, '@')) == 0)
continue;
/*
* If this is the first node with a given name property,
* add a symlink with the name property as its name.
*/
sib = NULL;
while ((sib = of_get_next_child(np, sib)) && sib != child)
if (sib->name && strcmp(sib->name, child->name) == 0)
break;
if (sib == child && strncmp(p, child->name, l) != 0) {
al = proc_symlink(child->name, de, ent->name);
if (al == 0) {
of_node_put(sib);
break;
}
set_node_name_link(child, al);
*lastp = al;
lastp = &al->next;
}
of_node_put(sib);
/*
* Add another directory with the @address part as its name.
*/
al = proc_symlink(at, de, ent->name);
if (al == 0)
break;
set_node_addr_link(child, al);
*lastp = al;
lastp = &al->next;
}
of_node_put(child);
*lastp = NULL;
de->subdir = list;
}

13
include/asm-ppc64/prom.h
View File

@ -147,9 +147,7 @@ struct device_node {
struct device_node *sibling;
struct device_node *next; /* next device of same type */
struct device_node *allnext; /* next in list of all nodes */
struct proc_dir_entry *pde; /* this node's proc directory */
struct proc_dir_entry *name_link; /* name symlink */
struct proc_dir_entry *addr_link; /* addr symlink */
struct proc_dir_entry *pde; /* this node's proc directory */
struct kref kref;
unsigned long _flags;
};
@ -174,15 +172,6 @@ static inline void set_node_proc_entry(struct device_node *dn, struct proc_dir_e
dn->pde = de;
}
static void inline set_node_name_link(struct device_node *dn, struct proc_dir_entry *de)
{
dn->name_link = de;
}
static void inline set_node_addr_link(struct device_node *dn, struct proc_dir_entry *de)
{
dn->addr_link = de;
}
/* OBSOLETE: Old stlye node lookup */
extern struct device_node *find_devices(const char *name);