mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-02 23:06:50 +07:00
5f64f73957
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>
137 lines
3.1 KiB
C
137 lines
3.1 KiB
C
/*
|
|
* proc_devtree.c - handles /proc/device-tree
|
|
*
|
|
* Copyright 1997 Paul Mackerras
|
|
*/
|
|
#include <linux/errno.h>
|
|
#include <linux/time.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/string.h>
|
|
#include <asm/prom.h>
|
|
#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)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
static struct proc_dir_entry *proc_device_tree;
|
|
|
|
/*
|
|
* Supply data on a read from /proc/device-tree/node/property.
|
|
*/
|
|
static int property_read_proc(char *page, char **start, off_t off,
|
|
int count, int *eof, void *data)
|
|
{
|
|
struct property *pp = data;
|
|
int n;
|
|
|
|
if (off >= pp->length) {
|
|
*eof = 1;
|
|
return 0;
|
|
}
|
|
n = pp->length - off;
|
|
if (n > count)
|
|
n = count;
|
|
else
|
|
*eof = 1;
|
|
memcpy(page, pp->value + off, n);
|
|
*start = page;
|
|
return n;
|
|
}
|
|
|
|
/*
|
|
* For a node with a name like "gc@10", we make symlinks called "gc"
|
|
* and "@10" to it.
|
|
*/
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct property *pp;
|
|
struct proc_dir_entry *ent;
|
|
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);
|
|
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;
|
|
}
|
|
de->subdir = list;
|
|
}
|
|
|
|
/*
|
|
* Called on initialization to set up the /proc/device-tree subtree
|
|
*/
|
|
void proc_device_tree_init(void)
|
|
{
|
|
struct device_node *root;
|
|
if ( !have_of )
|
|
return;
|
|
proc_device_tree = proc_mkdir("device-tree", NULL);
|
|
if (proc_device_tree == 0)
|
|
return;
|
|
root = of_find_node_by_path("/");
|
|
if (root == 0) {
|
|
printk(KERN_ERR "/proc/device-tree: can't find root\n");
|
|
return;
|
|
}
|
|
proc_device_tree_add_node(root, proc_device_tree);
|
|
of_node_put(root);
|
|
}
|