The device tree data structure uses a custom linked list implementation which is baroque and prone to bugs. Replace the allnodes list with a list_head and the common list_head accessor functions.
At the same time, move the private for_each_of_allnodes() macro into drivers/of/base.c. It must not be used outside of the core code because the macro doesn't take into account device tree locking. Signed-off-by: Grant Likely <[email protected]> Cc: Rob Herring <[email protected]> --- arch/arm/mach-vexpress/v2m.c | 2 +- drivers/of/base.c | 126 +++++++++++++++++++----------------- drivers/of/fdt.c | 27 ++++---- drivers/of/pdt.c | 26 +++----- drivers/pci/hotplug/rpadlpar_core.c | 2 +- include/linux/of.h | 9 ++- include/linux/of_fdt.h | 3 +- include/linux/of_pdt.h | 3 +- 8 files changed, 96 insertions(+), 102 deletions(-) diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c index 4f8b8cb17ff5..57151ba5edee 100644 --- a/arch/arm/mach-vexpress/v2m.c +++ b/arch/arm/mach-vexpress/v2m.c @@ -412,7 +412,7 @@ void __init v2m_dt_init_early(void) vexpress_sysreg_of_early_init(); /* Confirm board type against DT property, if available */ - if (of_property_read_u32(of_allnodes, "arm,hbi", &dt_hbi) == 0) { + if (of_property_read_u32(of_root, "arm,hbi", &dt_hbi) == 0) { u32 hbi = vexpress_get_hbi(VEXPRESS_SITE_MASTER); if (WARN_ON(dt_hbi != hbi)) diff --git a/drivers/of/base.c b/drivers/of/base.c index 567e6e1b7921..6c0bd86b802f 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -31,14 +31,22 @@ LIST_HEAD(aliases_lookup); -struct device_node *of_allnodes; +LIST_HEAD(of_allnodes); EXPORT_SYMBOL(of_allnodes); -struct device_node *of_chosen; -struct device_node *of_aliases; +struct device_node *of_root = NULL; +struct device_node *of_chosen = NULL; +struct device_node *of_aliases = NULL; static struct device_node *of_stdout; static struct kset *of_kset; +#define of_allnodes_prepare(dn) \ + list_prepare_entry(dn, &of_allnodes, allnext) +#define for_each_of_allnodes(dn) \ + list_for_each_entry(dn, &of_allnodes, allnext) +#define for_each_of_allnodes_continue(dn) \ + list_for_each_entry_continue(dn, &of_allnodes, allnext) + /* * Used to protect the of_aliases; but also overloaded to hold off addition of * nodes to sysfs @@ -299,7 +307,7 @@ static int __init of_init(void) mutex_unlock(&of_aliases_mutex); /* Symlink in /proc as required by userspace ABI */ - if (of_allnodes) + if (of_root) proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base"); return 0; @@ -348,18 +356,18 @@ EXPORT_SYMBOL(of_find_property); * Returns a node pointer with refcount incremented, use * of_node_put() on it when done. */ -struct device_node *of_find_all_nodes(struct device_node *prev) +struct device_node *of_find_all_nodes(struct device_node *np) { - struct device_node *np; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); - np = prev ? prev->allnext : of_allnodes; - for (; np != NULL; np = np->allnext) - if (of_node_get(np)) - break; - of_node_put(prev); + of_node_put(np); + np = list_next_entry(of_allnodes_prepare(np), allnext); + if (&np->allnext == &of_allnodes) + np = NULL; + of_node_get(np); raw_spin_unlock_irqrestore(&devtree_lock, flags); + return np; } EXPORT_SYMBOL(of_find_all_nodes); @@ -831,7 +839,7 @@ struct device_node *of_find_node_by_path(const char *path) unsigned long flags; if (strcmp(path, "/") == 0) - return of_node_get(of_allnodes); + return of_node_get(of_root); /* The path could begin with an alias */ if (*path != '/') { @@ -856,7 +864,7 @@ struct device_node *of_find_node_by_path(const char *path) /* Step down the tree matching path components */ raw_spin_lock_irqsave(&devtree_lock, flags); if (!np) - np = of_node_get(of_allnodes); + np = of_node_get(of_root); while (np && *path == '/') { path++; /* Increment past '/' delimiter */ np = __of_find_node_by_path(np, path); @@ -881,16 +889,18 @@ EXPORT_SYMBOL(of_find_node_by_path); struct device_node *of_find_node_by_name(struct device_node *from, const char *name) { - struct device_node *np; + struct device_node *np = NULL; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); - np = from ? from->allnext : of_allnodes; - for (; np; np = np->allnext) - if (np->name && (of_node_cmp(np->name, name) == 0) - && of_node_get(np)) - break; of_node_put(from); + from = of_allnodes_prepare(from); + for_each_of_allnodes_continue(from) { + if (from->name && (of_node_cmp(from->name, name) == 0)) { + np = of_node_get(from); + break; + } + } raw_spin_unlock_irqrestore(&devtree_lock, flags); return np; } @@ -911,16 +921,18 @@ EXPORT_SYMBOL(of_find_node_by_name); struct device_node *of_find_node_by_type(struct device_node *from, const char *type) { - struct device_node *np; + struct device_node *np = NULL; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); - np = from ? from->allnext : of_allnodes; - for (; np; np = np->allnext) - if (np->type && (of_node_cmp(np->type, type) == 0) - && of_node_get(np)) - break; of_node_put(from); + from = of_allnodes_prepare(from); + for_each_of_allnodes_continue(from) { + if (from->type && (of_node_cmp(from->type, type) == 0)) { + np = of_node_get(from); + break; + } + } raw_spin_unlock_irqrestore(&devtree_lock, flags); return np; } @@ -943,18 +955,20 @@ EXPORT_SYMBOL(of_find_node_by_type); struct device_node *of_find_compatible_node(struct device_node *from, const char *type, const char *compatible) { - struct device_node *np; + struct device_node *np = NULL; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); - np = from ? from->allnext : of_allnodes; - for (; np; np = np->allnext) { - if (__of_device_is_compatible(np, compatible, type, NULL) && - of_node_get(np)) + of_node_put(from); + from = of_allnodes_prepare(from); + for_each_of_allnodes_continue(from) { + if (__of_device_is_compatible(from, compatible, type, NULL)) { + np = of_node_get(from); break; + } } - of_node_put(from); raw_spin_unlock_irqrestore(&devtree_lock, flags); + return np; } EXPORT_SYMBOL(of_find_compatible_node); @@ -974,22 +988,22 @@ EXPORT_SYMBOL(of_find_compatible_node); struct device_node *of_find_node_with_property(struct device_node *from, const char *prop_name) { - struct device_node *np; + struct device_node *np = NULL; struct property *pp; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); - np = from ? from->allnext : of_allnodes; - for (; np; np = np->allnext) { - for (pp = np->properties; pp; pp = pp->next) { + of_node_put(from); + from = of_allnodes_prepare(from); + for_each_of_allnodes_continue(from) { + for (pp = from->properties; pp; pp = pp->next) { if (of_prop_cmp(pp->name, prop_name) == 0) { - of_node_get(np); + np = of_node_get(from); goto out; } } } -out: - of_node_put(from); + out: raw_spin_unlock_irqrestore(&devtree_lock, flags); return np; } @@ -1054,7 +1068,7 @@ struct device_node *of_find_matching_node_and_match(struct device_node *from, const struct of_device_id *matches, const struct of_device_id **match) { - struct device_node *np; + struct device_node *np = NULL; const struct of_device_id *m; unsigned long flags; @@ -1062,16 +1076,16 @@ struct device_node *of_find_matching_node_and_match(struct device_node *from, *match = NULL; raw_spin_lock_irqsave(&devtree_lock, flags); - np = from ? from->allnext : of_allnodes; - for (; np; np = np->allnext) { - m = __of_match_node(matches, np); - if (m && of_node_get(np)) { + of_node_put(from); + from = of_allnodes_prepare(from); + for_each_of_allnodes_continue(from) { + if ((m = __of_match_node(matches, from))) { + np = of_node_get(from); if (match) *match = m; break; } } - of_node_put(from); raw_spin_unlock_irqrestore(&devtree_lock, flags); return np; } @@ -1113,14 +1127,16 @@ EXPORT_SYMBOL_GPL(of_modalias_node); */ struct device_node *of_find_node_by_phandle(phandle handle) { - struct device_node *np; + struct device_node *tmp, *np = NULL; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); - for (np = of_allnodes; np; np = np->allnext) - if (np->phandle == handle) + for_each_of_allnodes(tmp) { + if (tmp->phandle == handle) { + np = of_node_get(tmp); break; - of_node_get(np); + } + } raw_spin_unlock_irqrestore(&devtree_lock, flags); return np; } @@ -1959,10 +1975,9 @@ int of_attach_node(struct device_node *np) return rc; raw_spin_lock_irqsave(&devtree_lock, flags); + list_add_tail(&np->allnext, &of_allnodes); np->sibling = np->parent->child; - np->allnext = of_allnodes; np->parent->child = np; - of_allnodes = np; of_node_clear_flag(np, OF_DETACHED); raw_spin_unlock_irqrestore(&devtree_lock, flags); @@ -2000,16 +2015,7 @@ int of_detach_node(struct device_node *np) return rc; } - if (of_allnodes == np) - of_allnodes = np->allnext; - else { - struct device_node *prev; - for (prev = of_allnodes; - prev->allnext != np; - prev = prev->allnext) - ; - prev->allnext = np->allnext; - } + list_del(&np->allnext); if (parent->child == np) parent->child = np->sibling; diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 17be90f5445f..6876ac3d4b30 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -96,14 +96,14 @@ static void *unflatten_dt_alloc(void **mem, unsigned long size, * @mem: Memory chunk to use for allocating device nodes and properties * @p: pointer to node in flat tree * @dad: Parent struct device_node - * @allnextpp: pointer to ->allnext from last allocated device_node + * @allnext: list of ->allnext from this tree * @fpsize: Size of the node path up at the current depth. */ static void * unflatten_dt_node(void *blob, void *mem, int *poffset, struct device_node *dad, - struct device_node ***allnextpp, + struct list_head *allnext, unsigned long fpsize) { const __be32 *p; @@ -151,7 +151,7 @@ static void * unflatten_dt_node(void *blob, np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl, __alignof__(struct device_node)); - if (allnextpp) { + if (allnext) { char *fn; of_node_init(np); np->full_name = fn = ((char *)np) + sizeof(*np); @@ -173,8 +173,7 @@ static void * unflatten_dt_node(void *blob, memcpy(fn, pathp, l); prev_pp = &np->properties; - **allnextpp = np; - *allnextpp = &np->allnext; + list_add_tail(&np->allnext, allnext); if (dad != NULL) { np->parent = dad; /* we temporarily use the next field as `last_child'*/ @@ -205,7 +204,7 @@ static void * unflatten_dt_node(void *blob, has_name = 1; pp = unflatten_dt_alloc(&mem, sizeof(struct property), __alignof__(struct property)); - if (allnextpp) { + if (allnext) { /* We accept flattened tree phandles either in * ePAPR-style "phandle" properties, or the * legacy "linux,phandle" properties. If both @@ -247,7 +246,7 @@ static void * unflatten_dt_node(void *blob, sz = (pa - ps) + 1; pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz, __alignof__(struct property)); - if (allnextpp) { + if (allnext) { pp->name = "name"; pp->length = sz; pp->value = pp + 1; @@ -259,7 +258,7 @@ static void * unflatten_dt_node(void *blob, (char *)pp->value); } } - if (allnextpp) { + if (allnext) { *prev_pp = NULL; np->name = of_get_property(np, "name", NULL); np->type = of_get_property(np, "device_type", NULL); @@ -275,7 +274,7 @@ static void * unflatten_dt_node(void *blob, if (depth < 0) depth = 0; while (*poffset > 0 && depth > old_depth) - mem = unflatten_dt_node(blob, mem, poffset, np, allnextpp, + mem = unflatten_dt_node(blob, mem, poffset, np, allnext, fpsize); if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND) @@ -297,13 +296,12 @@ static void * unflatten_dt_node(void *blob, * for the resulting tree */ static void __unflatten_device_tree(void *blob, - struct device_node **mynodes, + struct list_head *allnext, void * (*dt_alloc)(u64 size, u64 align)) { unsigned long size; int start; void *mem; - struct device_node **allnextp = mynodes; pr_debug(" -> unflatten_device_tree()\n"); @@ -339,11 +337,10 @@ static void __unflatten_device_tree(void *blob, /* Second pass, do actual unflattening */ start = 0; - unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0); + unflatten_dt_node(blob, mem, &start, NULL, allnext, 0); if (be32_to_cpup(mem + size) != 0xdeadbeef) pr_warning("End of tree marker overwritten: %08x\n", be32_to_cpup(mem + size)); - *allnextp = NULL; pr_debug(" <- unflatten_device_tree()\n"); } @@ -361,8 +358,7 @@ static void *kernel_tree_alloc(u64 size, u64 align) * pointers of the nodes so the normal device-tree walking functions * can be used. */ -void of_fdt_unflatten_tree(unsigned long *blob, - struct device_node **mynodes) +void of_fdt_unflatten_tree(unsigned long *blob, struct list_head *mynodes) { __unflatten_device_tree(blob, mynodes, &kernel_tree_alloc); } @@ -904,6 +900,7 @@ void __init unflatten_device_tree(void) { __unflatten_device_tree(initial_boot_params, &of_allnodes, early_init_dt_alloc_memory_arch); + of_root = list_first_entry_or_null(&of_allnodes, struct device_node, allnext); /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ of_alias_scan(early_init_dt_alloc_memory_arch); diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c index 36b4035881b0..38dd814870b4 100644 --- a/drivers/of/pdt.c +++ b/drivers/of/pdt.c @@ -25,8 +25,7 @@ static struct of_pdt_ops *of_pdt_prom_ops __initdata; -void __initdata (*of_pdt_build_more)(struct device_node *dp, - struct device_node ***nextp); +void __initdata (*of_pdt_build_more)(struct device_node *dp); #if defined(CONFIG_SPARC) unsigned int of_pdt_unique_id __initdata; @@ -192,8 +191,7 @@ static struct device_node * __init of_pdt_create_node(phandle node, } static struct device_node * __init of_pdt_build_tree(struct device_node *parent, - phandle node, - struct device_node ***nextp) + phandle node) { struct device_node *ret = NULL, *prev_sibling = NULL; struct device_node *dp; @@ -210,16 +208,15 @@ static struct device_node * __init of_pdt_build_tree(struct device_node *parent, ret = dp; prev_sibling = dp; - *(*nextp) = dp; - *nextp = &dp->allnext; + list_add_tail(&of_allnodes, &np->allnext); dp->full_name = of_pdt_build_full_name(dp); dp->child = of_pdt_build_tree(dp, - of_pdt_prom_ops->getchild(node), nextp); + of_pdt_prom_ops->getchild(node)); if (of_pdt_build_more) - of_pdt_build_more(dp, nextp); + of_pdt_build_more(dp); node = of_pdt_prom_ops->getsibling(node); } @@ -234,20 +231,17 @@ static void * __init kernel_tree_alloc(u64 size, u64 align) void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops) { - struct device_node **nextp; - BUG_ON(!ops); of_pdt_prom_ops = ops; - of_allnodes = of_pdt_create_node(root_node, NULL); + of_root = of_pdt_create_node(root_node, NULL); #if defined(CONFIG_SPARC) - of_allnodes->path_component_name = ""; + of_root->path_component_name = ""; #endif - of_allnodes->full_name = "/"; + of_root->full_name = "/"; - nextp = &of_allnodes->allnext; - of_allnodes->child = of_pdt_build_tree(of_allnodes, - of_pdt_prom_ops->getchild(of_allnodes->phandle), &nextp); + list_add_tail(&of_allnodes, &of_root->allnext); + of_root->child = of_pdt_build_tree(of_root, of_pdt_prom_ops->getchild(of_root->phandle)); /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ of_alias_scan(kernel_tree_alloc); diff --git a/drivers/pci/hotplug/rpadlpar_core.c b/drivers/pci/hotplug/rpadlpar_core.c index 4fcdeedda31b..e25e4d1ec241 100644 --- a/drivers/pci/hotplug/rpadlpar_core.c +++ b/drivers/pci/hotplug/rpadlpar_core.c @@ -68,7 +68,7 @@ static struct device_node *find_php_slot_pci_node(char *drc_name, char *type; int rc; - while ((np = of_find_node_by_name(np, "pci"))) { + for_each_node_by_name(np, "pci") { rc = rpaphp_get_drc_props(np, NULL, &name, &type, NULL); if (rc == 0) if (!strcmp(drc_name, name) && !strcmp(drc_type, type)) diff --git a/include/linux/of.h b/include/linux/of.h index 3bad8d106e0e..e082db3c284f 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -56,7 +56,7 @@ struct device_node { struct device_node *child; struct device_node *sibling; struct device_node *next; /* next device of same type */ - struct device_node *allnext; /* next in list of all nodes */ + struct list_head allnext; struct kobject kobj; unsigned long _flags; void *data; @@ -110,14 +110,15 @@ static inline void of_node_put(struct device_node *node) { } #ifdef CONFIG_OF /* Pointer for first entry in chain of all nodes. */ -extern struct device_node *of_allnodes; +extern struct list_head of_allnodes; +extern struct device_node *of_root; extern struct device_node *of_chosen; extern struct device_node *of_aliases; extern raw_spinlock_t devtree_lock; static inline bool of_have_populated_dt(void) { - return of_allnodes != NULL; + return !list_empty(&of_allnodes); } static inline bool of_node_is_root(const struct device_node *node) @@ -208,8 +209,6 @@ static inline const char *of_node_full_name(const struct device_node *np) return np ? np->full_name : "<no-node>"; } -#define for_each_of_allnodes(dn) \ - for (dn = of_allnodes; dn; dn = dn->allnext) extern struct device_node *of_find_node_by_name(struct device_node *from, const char *name); extern struct device_node *of_find_node_by_type(struct device_node *from, diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index 5c0ab057eecf..efa7615a1ce9 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -35,8 +35,7 @@ extern int of_fdt_is_compatible(const void *blob, const char *compat); extern int of_fdt_match(const void *blob, unsigned long node, const char *const *compat); -extern void of_fdt_unflatten_tree(unsigned long *blob, - struct device_node **mynodes); +extern void of_fdt_unflatten_tree(unsigned long *blob, struct list_head *mynodes); /* TBD: Temporary export of fdt globals - remove when code fully merged */ extern int __initdata dt_root_addr_cells; diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h index c65a18a0cfdf..7e09244bb679 100644 --- a/include/linux/of_pdt.h +++ b/include/linux/of_pdt.h @@ -39,7 +39,6 @@ extern void *prom_early_alloc(unsigned long size); /* for building the device tree */ extern void of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops); -extern void (*of_pdt_build_more)(struct device_node *dp, - struct device_node ***nextp); +extern void (*of_pdt_build_more)(struct device_node *dp); #endif /* _LINUX_OF_PDT_H */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
