shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-08 03:40:35 +09:00
Code Issues Packages Projects Releases Wiki Activity

UPSTREAM: nvmem: use kref

Browse Source 
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().

Bug: 154188491
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>
(cherry picked from commit c1de7f43bd)
Signed-off-by: Will McVicker <willmcvicker@google.com>
Change-Id: I4c05a0614255d72163b79526324e41dd4b0100ef
This commit is contained in:
Bartosz Golaszewski
2018-09-21 06:40:08 -07:00
committed by Will McVicker
parent 8c9e954cea
commit 38697b7c72
1 changed files with 22 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

44
drivers/nvmem/core.c
View File

@@ -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>
@@ -32,7 +33,7 @@ struct nvmem_device {
int stride;
int word_size;
int id;
int users;
struct kref refcnt;
size_t size;
bool read_only;
int flags;
@@ -525,6 +526,8 @@ 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)
@@ -598,6 +601,20 @@ 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
*
@@ -607,19 +624,7 @@ 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;
}
@@ -714,7 +719,6 @@ static struct nvmem_device *__nvmem_device_get(struct device_node *np,
}
}
nvmem->users++;
mutex_unlock(&nvmem_mutex);
if (!try_module_get(nvmem->owner)) {
@@ -722,22 +726,18 @@ static struct nvmem_device *__nvmem_device_get(struct device_node *np,
"could not increase module refcount for cell %s\n",
nvmem->name);
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)