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| author | Bartosz Golaszewski <bgolaszewski@baylibre.com> | 2018-09-21 06:40:08 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-28 15:14:54 +0200 |
| commit | c1de7f43bd84271e438a4f2dadc4ba9a353baaea (patch) | |
| tree | f08b22fddaa52f2d55f6b2cb34bacc936e8838a9 | |
| parent | fa72d847d68d7833b77a4bef944cf2c5baf56f49 (diff) | |
| download | linux-c1de7f43bd84271e438a4f2dadc4ba9a353baaea.tar.gz linux-c1de7f43bd84271e438a4f2dadc4ba9a353baaea.tar.bz2 linux-c1de7f43bd84271e438a4f2dadc4ba9a353baaea.zip | |
nvmem: use kref
Use kref for reference counting. Use an approach similar to the one
seen in the common clock subsystem: don't actually destroy the nvmem
device until the last user puts it. This way we can get rid of the
users check from nvmem_unregister().
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/nvmem/core.c | 44 |
1 files changed, 22 insertions, 22 deletions
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 0ef84441ebe5..920b56e500cc 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -19,6 +19,7 @@ #include <linux/fs.h> #include <linux/idr.h> #include <linux/init.h> +#include <linux/kref.h> #include <linux/module.h> #include <linux/nvmem-consumer.h> #include <linux/nvmem-provider.h> @@ -31,7 +32,7 @@ struct nvmem_device { int stride; int word_size; int id; - int users; + struct kref refcnt; size_t size; bool read_only; int flags; @@ -463,6 +464,8 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) return ERR_PTR(rval); } + kref_init(&nvmem->refcnt); + nvmem->id = rval; nvmem->owner = config->owner; if (!nvmem->owner && config->dev->driver) @@ -532,6 +535,20 @@ err_put_device: } EXPORT_SYMBOL_GPL(nvmem_register); +static void nvmem_device_release(struct kref *kref) +{ + struct nvmem_device *nvmem; + + nvmem = container_of(kref, struct nvmem_device, refcnt); + + if (nvmem->flags & FLAG_COMPAT) + device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); + + nvmem_device_remove_all_cells(nvmem); + device_del(&nvmem->dev); + put_device(&nvmem->dev); +} + /** * nvmem_unregister() - Unregister previously registered nvmem device * @@ -541,19 +558,7 @@ EXPORT_SYMBOL_GPL(nvmem_register); */ int nvmem_unregister(struct nvmem_device *nvmem) { - mutex_lock(&nvmem_mutex); - if (nvmem->users) { - mutex_unlock(&nvmem_mutex); - return -EBUSY; - } - mutex_unlock(&nvmem_mutex); - - if (nvmem->flags & FLAG_COMPAT) - device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); - - nvmem_device_remove_all_cells(nvmem); - device_del(&nvmem->dev); - put_device(&nvmem->dev); + kref_put(&nvmem->refcnt, nvmem_device_release); return 0; } @@ -647,7 +652,6 @@ static struct nvmem_device *__nvmem_device_get(struct device_node *np, } } - nvmem->users++; mutex_unlock(&nvmem_mutex); if (!try_module_get(nvmem->owner)) { @@ -655,22 +659,18 @@ static struct nvmem_device *__nvmem_device_get(struct device_node *np, "could not increase module refcount for cell %s\n", nvmem_dev_name(nvmem)); - mutex_lock(&nvmem_mutex); - nvmem->users--; - mutex_unlock(&nvmem_mutex); - return ERR_PTR(-EINVAL); } + kref_get(&nvmem->refcnt); + return nvmem; } static void __nvmem_device_put(struct nvmem_device *nvmem) { module_put(nvmem->owner); - mutex_lock(&nvmem_mutex); - nvmem->users--; - mutex_unlock(&nvmem_mutex); + kref_put(&nvmem->refcnt, nvmem_device_release); } static struct nvmem_device *nvmem_find(const char *name) |