From 5f64f73957f6cae3222f97f2599199ee562f7f3f Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 1 Jun 2005 17:07:27 +1000 Subject: [PATCH] [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 Signed-off-by: Linus Torvalds --- arch/ppc64/kernel/pSeries_reconfig.c | 8 -- fs/proc/proc_devtree.c | 105 ++++++++++----------------- include/asm-ppc64/prom.h | 13 +--- 3 files changed, 39 insertions(+), 87 deletions(-) diff --git a/arch/ppc64/kernel/pSeries_reconfig.c b/arch/ppc64/kernel/pSeries_reconfig.c index cb5443f2e49b..dc2a69d412a2 100644 --- a/arch/ppc64/kernel/pSeries_reconfig.c +++ b/arch/ppc64/kernel/pSeries_reconfig.c @@ -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); } diff --git a/fs/proc/proc_devtree.c b/fs/proc/proc_devtree.c index 67423c696c0a..6fd57f154197 100644 --- a/fs/proc/proc_devtree.c +++ b/fs/proc/proc_devtree.c @@ -12,15 +12,8 @@ #include #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; - } - set_node_name_link(child, al); - *lastp = al; - lastp = &al->next; + if (ent != NULL) { + printk(KERN_WARNING "device-tree: property \"%s\" name" + " conflicts with node in %s\n", pp->name, + np->full_name); + continue; } - 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; } diff --git a/include/asm-ppc64/prom.h b/include/asm-ppc64/prom.h index 2440a2c90ae9..04b1a84f7ca3 100644 --- a/include/asm-ppc64/prom.h +++ b/include/asm-ppc64/prom.h @@ -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); -- 2.20.1