| Message ID | 1399993115-21552-3-git-send-email-grant.likely@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 5/13/2014 7:58 AM, Grant Likely wrote: > Make of_find_node_by_path() handle aliases as prefixes. To make this > work the name search is refactored to search by path component instead > of by full string. This should be a more efficient search, and it makes > it possible to start a search at a subnode of a tree. > > Signed-off-by: David Daney <david.daney@cavium.com> > Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> > [grant.likely: Rework to not require allocating at runtime] > Acked-by: Rob Herring <robh@kernel.org> > Signed-off-by: Grant Likely <grant.likely@linaro.org> > --- > drivers/of/base.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++---- > 1 file changed, 56 insertions(+), 4 deletions(-) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index 6e240698353b..60089b9a3014 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -771,9 +771,38 @@ struct device_node *of_get_child_by_name(const struct device_node *node, > } > EXPORT_SYMBOL(of_get_child_by_name); > > +static struct device_node *__of_find_node_by_path(struct device_node *parent, > + const char *path) > +{ > + struct device_node *child; > + int len = strchrnul(path, '/') - path; > + > + if (!len) > + return parent; (!len) is true if the the final character of the path passed into of_find_node_by_path() was "/". Strictly speaking, ->full_name will never end with "/", so the return value should be NULL, indicating that the match fails. > + > + for_each_child_of_node(parent, child) { > + const char *name = strrchr(child->full_name, '/'); > + if (WARN(!name, "malformed device_node %s\n", child->full_name)) > + continue; > + name++; Why go to the effort of finding the final component of child->full_name instead of just using child->name? > + if (strncmp(path, name, len) == 0 && (strlen(name) == len)) > + return child; > + } > + return NULL; > +} > + > /** > * of_find_node_by_path - Find a node matching a full OF path > * @path: The full path to match > + * @path: Either the full path to match, or if the path does not Delete the old @path description. > + * start with '/', the name of a property of the /aliases > + * node (an alias). In the case of an alias, the node > + * matching the alias' value will be returned. > + * > + * Valid paths: > + * /foo/bar Full path > + * foo Valid alias > + * foo/bar Valid alias + relative path > * > * Returns a node pointer with refcount incremented, use > * of_node_put() on it when done. > @@ -781,13 +810,36 @@ EXPORT_SYMBOL(of_get_child_by_name); > struct device_node *of_find_node_by_path(const char *path) > { > struct device_node *np = of_allnodes; > + struct property *pp; > unsigned long flags; > > + /* The path could begin with an alias */ > + if (*path != '/') { > + char *p = strchrnul(path, '/'); > + int len = p - path; > + > + /* of_aliases must not be NULL */ > + if (!of_aliases) > + return NULL; > + > + np = NULL; > + for_each_property_of_node(of_aliases, pp) { > + if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) { > + np = of_find_node_by_path(pp->value); > + break; > + } > + } > + if (!np) > + return NULL; > + path = p; > + } > + > + /* Step down the tree matching path components */ > raw_spin_lock_irqsave(&devtree_lock, flags); > - for (; np; np = np->allnext) { > - if (np->full_name && (of_node_cmp(np->full_name, path) == 0) > - && of_node_get(np)) > - break; > + while (np && *path == '/') { > + path++; /* Increment past '/' delimiter */ > + np = __of_find_node_by_path(np, path); > + path = strchrnul(path, '/'); > } > raw_spin_unlock_irqrestore(&devtree_lock, flags); > return np; > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 15 May 2014 19:51:17 -0700, Frank Rowand <frowand.list@gmail.com> wrote: > On 5/13/2014 7:58 AM, Grant Likely wrote: > > Make of_find_node_by_path() handle aliases as prefixes. To make this > > work the name search is refactored to search by path component instead > > of by full string. This should be a more efficient search, and it makes > > it possible to start a search at a subnode of a tree. > > > > Signed-off-by: David Daney <david.daney@cavium.com> > > Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> > > [grant.likely: Rework to not require allocating at runtime] > > Acked-by: Rob Herring <robh@kernel.org> > > Signed-off-by: Grant Likely <grant.likely@linaro.org> > > --- > > drivers/of/base.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++---- > > 1 file changed, 56 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/of/base.c b/drivers/of/base.c > > index 6e240698353b..60089b9a3014 100644 > > --- a/drivers/of/base.c > > +++ b/drivers/of/base.c > > @@ -771,9 +771,38 @@ struct device_node *of_get_child_by_name(const struct device_node *node, > > } > > EXPORT_SYMBOL(of_get_child_by_name); > > > > +static struct device_node *__of_find_node_by_path(struct device_node *parent, > > + const char *path) > > +{ > > + struct device_node *child; > > + int len = strchrnul(path, '/') - path; > > + > > + if (!len) > > + return parent; > > (!len) is true if the the final character of the path passed into of_find_node_by_path() > was "/". Strictly speaking, ->full_name will never end with "/", so the return value > should be NULL, indicating that the match fails. Ah, good catch. I should add a test case for that. > > > + > > + for_each_child_of_node(parent, child) { > > + const char *name = strrchr(child->full_name, '/'); > > + if (WARN(!name, "malformed device_node %s\n", child->full_name)) > > + continue; > > + name++; > > Why go to the effort of finding the final component of child->full_name instead > of just using child->name? Because child->name and the final component of child->full_name is not the same thing. child->name has the unit address stripped off. It is part of how OpenFirmware expects to be used. New drivers are never supposed to be matching by node name, but I don't currently have a good way to go through any driver depending on the OpenFirmware behaviour. Ideally I'd like to get rid of the difference. > > > + if (strncmp(path, name, len) == 0 && (strlen(name) == len)) > > + return child; > > + } > > + return NULL; > > +} > > + > > /** > > * of_find_node_by_path - Find a node matching a full OF path > > * @path: The full path to match > > + * @path: Either the full path to match, or if the path does not > > Delete the old @path description. Oops, thanks. > > > > + * start with '/', the name of a property of the /aliases > > + * node (an alias). In the case of an alias, the node > > + * matching the alias' value will be returned. > > + * > > + * Valid paths: > > + * /foo/bar Full path > > + * foo Valid alias > > + * foo/bar Valid alias + relative path > > * > > * Returns a node pointer with refcount incremented, use > > * of_node_put() on it when done. > > @@ -781,13 +810,36 @@ EXPORT_SYMBOL(of_get_child_by_name); > > struct device_node *of_find_node_by_path(const char *path) > > { > > struct device_node *np = of_allnodes; > > + struct property *pp; > > unsigned long flags; > > > > + /* The path could begin with an alias */ > > + if (*path != '/') { > > + char *p = strchrnul(path, '/'); > > + int len = p - path; > > + > > + /* of_aliases must not be NULL */ > > + if (!of_aliases) > > + return NULL; > > + > > + np = NULL; > > + for_each_property_of_node(of_aliases, pp) { > > + if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) { > > + np = of_find_node_by_path(pp->value); > > + break; > > + } > > + } > > + if (!np) > > + return NULL; > > + path = p; > > + } > > + > > + /* Step down the tree matching path components */ > > raw_spin_lock_irqsave(&devtree_lock, flags); > > - for (; np; np = np->allnext) { > > - if (np->full_name && (of_node_cmp(np->full_name, path) == 0) > > - && of_node_get(np)) > > - break; > > + while (np && *path == '/') { > > + path++; /* Increment past '/' delimiter */ > > + np = __of_find_node_by_path(np, path); > > + path = strchrnul(path, '/'); > > } > > raw_spin_unlock_irqrestore(&devtree_lock, flags); > > return np; > > > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/of/base.c b/drivers/of/base.c index 6e240698353b..60089b9a3014 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -771,9 +771,38 @@ struct device_node *of_get_child_by_name(const struct device_node *node, } EXPORT_SYMBOL(of_get_child_by_name); +static struct device_node *__of_find_node_by_path(struct device_node *parent, + const char *path) +{ + struct device_node *child; + int len = strchrnul(path, '/') - path; + + if (!len) + return parent; + + for_each_child_of_node(parent, child) { + const char *name = strrchr(child->full_name, '/'); + if (WARN(!name, "malformed device_node %s\n", child->full_name)) + continue; + name++; + if (strncmp(path, name, len) == 0 && (strlen(name) == len)) + return child; + } + return NULL; +} + /** * of_find_node_by_path - Find a node matching a full OF path * @path: The full path to match + * @path: Either the full path to match, or if the path does not + * start with '/', the name of a property of the /aliases + * node (an alias). In the case of an alias, the node + * matching the alias' value will be returned. + * + * Valid paths: + * /foo/bar Full path + * foo Valid alias + * foo/bar Valid alias + relative path * * Returns a node pointer with refcount incremented, use * of_node_put() on it when done. @@ -781,13 +810,36 @@ EXPORT_SYMBOL(of_get_child_by_name); struct device_node *of_find_node_by_path(const char *path) { struct device_node *np = of_allnodes; + struct property *pp; unsigned long flags; + /* The path could begin with an alias */ + if (*path != '/') { + char *p = strchrnul(path, '/'); + int len = p - path; + + /* of_aliases must not be NULL */ + if (!of_aliases) + return NULL; + + np = NULL; + for_each_property_of_node(of_aliases, pp) { + if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) { + np = of_find_node_by_path(pp->value); + break; + } + } + if (!np) + return NULL; + path = p; + } + + /* Step down the tree matching path components */ raw_spin_lock_irqsave(&devtree_lock, flags); - for (; np; np = np->allnext) { - if (np->full_name && (of_node_cmp(np->full_name, path) == 0) - && of_node_get(np)) - break; + while (np && *path == '/') { + path++; /* Increment past '/' delimiter */ + np = __of_find_node_by_path(np, path); + path = strchrnul(path, '/'); } raw_spin_unlock_irqrestore(&devtree_lock, flags); return np;