From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Jonathan Corbet <corbet@lwn.net>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J . Wysocki" <rafael@kernel.org>,
Guenter Roeck <linux@roeck-us.net>,
Jean Delvare <jdelvare@suse.com>
Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-hwmon@vger.kernel.org,
Bartosz Golaszewski <bgolaszewski@baylibre.com>
Subject: [PATCH 4/5] devres: provide devm_krealloc()
Date: Fri, 26 Jun 2020 18:55:34 +0200 [thread overview]
Message-ID: <20200626165535.7662-5-brgl@bgdev.pl> (raw)
In-Reply-To: <20200626165535.7662-1-brgl@bgdev.pl>
From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Implement the managed variant of krealloc(). This function works with
all memory allocated by devm_kmalloc() (or devres functions using it
implicitly like devm_kmemdup(), devm_kstrdup() etc.).
Managed realloc'ed chunks can be manually released with devm_kfree().
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
.../driver-api/driver-model/devres.rst | 1 +
drivers/base/devres.c | 42 +++++++++++++++++++
include/linux/device.h | 2 +
3 files changed, 45 insertions(+)
diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index e0b58c392e4f..0a2572c3813c 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -352,6 +352,7 @@ MEM
devm_kfree()
devm_kmalloc()
devm_kmalloc_array()
+ devm_krealloc()
devm_kmemdup()
devm_kstrdup()
devm_kvasprintf()
diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index 1df1fb10b2d9..baf41a290356 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -834,6 +834,48 @@ void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
}
EXPORT_SYMBOL_GPL(devm_kmalloc);
+void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
+{
+ struct devres *old_dr, *new_dr;
+ struct list_head old_head;
+ unsigned long flags;
+ void *ret = NULL;
+ size_t tot_size;
+
+ if (unlikely(!new_size)) {
+ devm_kfree(dev, ptr);
+ return ZERO_SIZE_PTR;
+ }
+
+ if (unlikely(!ptr))
+ return devm_kmalloc(dev, new_size, gfp);
+
+ if (!check_dr_size(new_size, &tot_size))
+ return NULL;
+
+ spin_lock_irqsave(&dev->devres_lock, flags);
+
+ old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr);
+ if (WARN_ONCE(!old_dr, "Memory chunk not managed or managed by a different device"))
+ goto out;
+
+ old_head = old_dr->node.entry;
+
+ new_dr = krealloc(old_dr, tot_size, gfp);
+ if (!new_dr)
+ goto out;
+
+ if (new_dr != old_dr)
+ list_replace(&old_head, &new_dr->node.entry);
+
+ ret = new_dr->data;
+
+out:
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(devm_krealloc);
+
/**
* devm_kstrdup - Allocate resource managed space and
* copy an existing string into that.
diff --git a/include/linux/device.h b/include/linux/device.h
index 9cadb647cacc..228063c6392c 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -201,6 +201,8 @@ int devres_release_group(struct device *dev, void *id);
/* managed devm_k.alloc/kfree for device drivers */
void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
+void *devm_krealloc(struct device *dev, void *ptr, size_t size,
+ gfp_t gfp) __must_check;
__printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp,
const char *fmt, va_list ap) __malloc;
__printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp,
--
2.26.1
next prev parent reply other threads:[~2020-06-26 16:56 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-26 16:55 [PATCH 0/5] devres: provide and use devm_krealloc() Bartosz Golaszewski
2020-06-26 16:55 ` [PATCH 1/5] devres: remove stray space from devm_kmalloc() definition Bartosz Golaszewski
2020-06-26 16:55 ` [PATCH 2/5] devres: move the size check from alloc_dr() into a separate function Bartosz Golaszewski
2020-06-26 16:55 ` [PATCH 3/5] device: remove 'extern' attribute from function prototypes in device.h Bartosz Golaszewski
2020-06-26 16:55 ` Bartosz Golaszewski [this message]
2020-06-26 16:55 ` [PATCH 5/5] hwmon: pmbus: use more devres helpers Bartosz Golaszewski
2020-06-26 21:50 ` Guenter Roeck
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