The component helper treats the void match data pointer as an opaque object which needs no further management. When device nodes being passed, this is not true: the caller should pass its refcount to the component helper, and there should be a way to drop the refcount when the matching information is destroyed.
This patch provides a per-match release method in addition to the match method to solve this issue. Rather than using component_match_add(), users should use component_match_add_release() which takes an additional function pointer for releasing this reference.
Signed-off-by: Russell King rmk+kernel@arm.linux.org.uk --- drivers/base/component.c | 101 ++++++++++++++++++++++++++++++---------------- include/linux/component.h | 28 +++++++++---- 2 files changed, 87 insertions(+), 42 deletions(-)
diff --git a/drivers/base/component.c b/drivers/base/component.c index d99b06b341fb..89f5cf68d80a 100644 --- a/drivers/base/component.c +++ b/drivers/base/component.c @@ -20,15 +20,18 @@
struct component;
+struct component_match_array { + void *data; + int (*compare)(struct device *, void *); + void (*release)(struct device *, void *); + struct component *component; + bool duplicate; +}; + struct component_match { size_t alloc; size_t num; - struct { - void *data; - int (*fn)(struct device *, void *); - struct component *component; - bool duplicate; - } compare[0]; + struct component_match_array *compare; };
struct master { @@ -92,6 +95,7 @@ static int find_components(struct master *master) * any components which are found to this master. */ for (i = 0; i < match->num; i++) { + struct component_match_array *mc = &match->compare[i]; struct component *c;
dev_dbg(master->dev, "Looking for component %zu\n", i); @@ -99,8 +103,7 @@ static int find_components(struct master *master) if (match->compare[i].component) continue;
- c = find_component(master, match->compare[i].fn, - match->compare[i].data); + c = find_component(master, mc->compare, mc->data); if (!c) { ret = -ENXIO; break; @@ -192,41 +195,55 @@ static void take_down_master(struct master *master) } }
-static size_t component_match_size(size_t num) +static void component_match_release(struct device *master, + struct component_match *match) +{ + unsigned int i; + + for (i = 0; i < match->num; i++) { + struct component_match_array *mc = &match->compare[i]; + + if (mc->release) + mc->release(master, mc->data); + } +} + +static void devm_component_match_release(struct device *dev, void *res) { - return offsetof(struct component_match, compare[num]); + component_match_release(dev, res); }
-static struct component_match *component_match_realloc(struct device *dev, +static int component_match_realloc(struct device *dev, struct component_match *match, size_t num) { - struct component_match *new; + struct component_match_array *new;
- if (match && match->alloc == num) - return match; + if (match->alloc == num) + return 0;
- new = devm_kmalloc(dev, component_match_size(num), GFP_KERNEL); + new = devm_kmalloc_array(dev, num, sizeof(*new), GFP_KERNEL); if (!new) - return ERR_PTR(-ENOMEM); + return -ENOMEM;
- if (match) { - memcpy(new, match, component_match_size(min(match->num, num))); - devm_kfree(dev, match); - } else { - new->num = 0; + if (match->compare) { + memcpy(new, match->compare, sizeof(*new) * + min(match->num, num)); + devm_kfree(dev, match->compare); } + match->compare = new; + match->alloc = num;
- new->alloc = num; - - return new; + return 0; }
/* - * Add a component to be matched. + * Add a component to be matched, with a release function. * * The match array is first created or extended if necessary. */ -void component_match_add(struct device *dev, struct component_match **matchptr, +void component_match_add_release(struct device *master, + struct component_match **matchptr, + void (*release)(struct device *, void *), int (*compare)(struct device *, void *), void *compare_data) { struct component_match *match = *matchptr; @@ -234,23 +251,37 @@ void component_match_add(struct device *dev, struct component_match **matchptr, if (IS_ERR(match)) return;
- if (!match || match->num == match->alloc) { - size_t new_size = match ? match->alloc + 16 : 15; + if (!match) { + match = devres_alloc(devm_component_match_release, + sizeof(*match), GFP_KERNEL); + if (!match) { + *matchptr = ERR_PTR(-ENOMEM); + return; + }
- match = component_match_realloc(dev, match, new_size); + devres_add(master, match);
*matchptr = match; + } + + if (match->num == match->alloc) { + size_t new_size = match ? match->alloc + 16 : 15; + int ret;
- if (IS_ERR(match)) + ret = component_match_realloc(master, match, new_size); + if (ret) { + *matchptr = ERR_PTR(ret); return; + } }
- match->compare[match->num].fn = compare; + match->compare[match->num].compare = compare; + match->compare[match->num].release = release; match->compare[match->num].data = compare_data; match->compare[match->num].component = NULL; match->num++; } -EXPORT_SYMBOL(component_match_add); +EXPORT_SYMBOL(component_match_add_release);
int component_master_add_with_match(struct device *dev, const struct component_master_ops *ops, @@ -260,9 +291,9 @@ int component_master_add_with_match(struct device *dev, int ret;
/* Reallocate the match array for its true size */ - match = component_match_realloc(dev, match, match->num); - if (IS_ERR(match)) - return PTR_ERR(match); + ret = component_match_realloc(dev, match, match->num); + if (ret) + return ret;
master = kzalloc(sizeof(*master), GFP_KERNEL); if (!master) diff --git a/include/linux/component.h b/include/linux/component.h index 71c434a6a5ee..a559eebc0e0f 100644 --- a/include/linux/component.h +++ b/include/linux/component.h @@ -1,24 +1,28 @@ #ifndef COMPONENT_H #define COMPONENT_H
+#include <linux/stddef.h> + struct device;
struct component_ops { - int (*bind)(struct device *, struct device *, void *); - void (*unbind)(struct device *, struct device *, void *); + int (*bind)(struct device *comp, struct device *master, + void *master_data); + void (*unbind)(struct device *comp, struct device *master, + void *master_data); };
int component_add(struct device *, const struct component_ops *); void component_del(struct device *, const struct component_ops *);
-int component_bind_all(struct device *, void *); -void component_unbind_all(struct device *, void *); +int component_bind_all(struct device *master, void *master_data); +void component_unbind_all(struct device *master, void *master_data);
struct master;
struct component_master_ops { - int (*bind)(struct device *); - void (*unbind)(struct device *); + int (*bind)(struct device *master); + void (*unbind)(struct device *master); };
void component_master_del(struct device *, @@ -28,7 +32,17 @@ struct component_match;
int component_master_add_with_match(struct device *, const struct component_master_ops *, struct component_match *); -void component_match_add(struct device *, struct component_match **, +void component_match_add_release(struct device *master, + struct component_match **matchptr, + void (*release)(struct device *, void *), int (*compare)(struct device *, void *), void *compare_data);
+static inline void component_match_add(struct device *master, + struct component_match **matchptr, + int (*compare)(struct device *, void *), void *compare_data) +{ + component_match_add_release(master, matchptr, NULL, compare, + compare_data); +} + #endif