Commit 5f64f739 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Linus Torvalds
Browse files

[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: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent f93ea234

arch/ppc64/kernel/pSeries_reconfig.c

+0 −8
Original line number Diff line number Diff line
@@ -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);

}

fs/proc/proc_devtree.c

+38 −67
Original line number Diff line number Diff line
@@ -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 (pp = np->properties; pp != 0; pp = pp->next) {

		/*

		 * 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;

		*lastp = ent;

		lastp = &ent->next;

	}

	child = NULL;

	while ((child = of_get_next_child(np, child))) {

	for (child = NULL; (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;

		ent->next = NULL;

		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;



	}

	of_node_put(child);

	for (pp = np->properties; pp != 0; pp = pp->next) {

		/*

		 * If this is the first node with a given name property,

		 * add a symlink with the name property as its name.

		 * 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.

		 */

		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);

		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;

		}

			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.

		 * Unfortunately proc_register puts each new entry

		 * at the beginning of the list.  So we rearrange them.

		 */

		al = proc_symlink(at, de, ent->name);

		if (al == 0)

		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;

		set_node_addr_link(child, al);

		*lastp = al;

		lastp = &al->next;

		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;

	}

	of_node_put(child);

	*lastp = NULL;

	de->subdir = list;

}

include/asm-ppc64/prom.h

+1 −12
Original line number Diff line number Diff line
@@ -148,8 +148,6 @@ struct device_node { 
	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  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);

CRA Git | Maintained and supported by SUSTech CRA and CCSE