[PATCH RFC 01/11] devres: add devm_alloc_percpu()

From: Madalin Bucur
Date: Tue Mar 17 2015 - 15:13:52 EST


Introduce managed counterparts for alloc_percpu() and free_percpu().
Add devm_alloc_percpu() and devm_free_percpu() into the managed
interfaces list.

Signed-off-by: Madalin Bucur <madalin.bucur@xxxxxxxxxxxxx>
Tested-by: Madalin-Cristian Bucur <madalin.bucur@xxxxxxxxxxxxx>
---
Documentation/driver-model/devres.txt | 4 +++
drivers/base/devres.c | 63 +++++++++++++++++++++++++++++++++++
include/linux/device.h | 19 +++++++++++
3 files changed, 86 insertions(+)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index 6d1e8ee..f105669 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -307,6 +307,10 @@ MEM
devm_kvasprintf()
devm_kzalloc()

+PER-CPU MEM
+ devm_alloc_percpu()
+ devm_free_percpu()
+
PCI
pcim_enable_device() : after success, all PCI ops become managed
pcim_pin_device() : keep PCI device enabled after release
diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index c8a53d1..6c76e75 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -984,3 +984,66 @@ void devm_free_pages(struct device *dev, unsigned long addr)
&devres));
}
EXPORT_SYMBOL_GPL(devm_free_pages);
+
+static void devm_percpu_release(struct device *dev, void *pdata)
+{
+ void __percpu *p;
+
+ p = *(void __percpu **)pdata;
+ free_percpu(p);
+}
+
+static int devm_percpu_match(struct device *dev, void *data, void *p)
+{
+ struct devres *devr = container_of(data, struct devres, data);
+
+ return *(void **)devr->data == p;
+}
+
+/**
+ * __devm_alloc_percpu - Resource-managed alloc_percpu
+ * @dev: Device to allocate per-cpu memory for
+ * @size: Size of per-cpu memory to allocate
+ * @align: Alignement of per-cpu memory to allocate
+ *
+ * Managed alloc_percpu. Per-cpu memory allocated with this function is
+ * automatically freed on driver detach.
+ *
+ * RETURNS:
+ * Pointer to allocated memory on success, NULL on failure.
+ */
+void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
+ size_t align)
+{
+ void *p;
+ void __percpu *pcpu;
+
+ pcpu = __alloc_percpu(size, align);
+ if (!pcpu)
+ return NULL;
+
+ p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
+ if (!p)
+ return NULL;
+
+ *(void __percpu **)p = pcpu;
+
+ devres_add(dev, p);
+
+ return pcpu;
+}
+EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
+
+/**
+ * devm_free_percpu - Resource-managed free_percpu
+ * @dev: Device this memory belongs to
+ * @pdata: Per-cpu memory to free
+ *
+ * Free memory allocated with devm_alloc_percpu().
+ */
+void devm_free_percpu(struct device *dev, void __percpu *pdata)
+{
+ WARN_ON(devres_destroy(dev, devm_percpu_release, devm_percpu_match,
+ (void *)pdata));
+}
+EXPORT_SYMBOL_GPL(devm_free_percpu);
diff --git a/include/linux/device.h b/include/linux/device.h
index 0eb8ee2..5b570f4 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -641,6 +641,25 @@ void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
int devm_add_action(struct device *dev, void (*action)(void *), void *data);
void devm_remove_action(struct device *dev, void (*action)(void *), void *data);

+/**
+ * devm_alloc_percpu - Resource-managed alloc_percpu
+ * @dev: Device to allocate per-cpu memory for
+ * @type: Type to allocate per-cpu memory for
+ *
+ * Managed alloc_percpu. Per-cpu memory allocated with this function is
+ * automatically freed on driver detach.
+ *
+ * RETURNS:
+ * Pointer to allocated memory on success, NULL on failure.
+ */
+#define devm_alloc_percpu(dev, type) \
+ (typeof(type) __percpu *)__devm_alloc_percpu(dev, sizeof(type), \
+ __alignof__(type))
+
+void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
+ size_t align);
+void devm_free_percpu(struct device *dev, void __percpu *pdata);
+
struct device_dma_parameters {
/*
* a low level driver may set these to teach IOMMU code about
--
1.7.11.7

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