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authorTejun Heo <htejun@gmail.com>2007-01-20 16:00:26 +0900
committerJeff Garzik <jeff@garzik.org>2007-02-09 17:39:36 -0500
commit9ac7849e35f705830f7b016ff272b0ff1f7ff759 (patch)
tree7f17cdff87e154937a15cc2ec8da9b4e6018ce8e /kernel/irq
parent77a527eadb425b60db3f5f0aae6a4c51c38e35e5 (diff)
downloadtalos-op-linux-9ac7849e35f705830f7b016ff272b0ff1f7ff759.tar.gz
talos-op-linux-9ac7849e35f705830f7b016ff272b0ff1f7ff759.zip
devres: device resource management
Implement device resource management, in short, devres. A device driver can allocate arbirary size of devres data which is associated with a release function. On driver detach, release function is invoked on the devres data, then, devres data is freed. devreses are typed by associated release functions. Some devreses are better represented by single instance of the type while others need multiple instances sharing the same release function. Both usages are supported. devreses can be grouped using devres group such that a device driver can easily release acquired resources halfway through initialization or selectively release resources (e.g. resources for port 1 out of 4 ports). This patch adds devres core including documentation and the following managed interfaces. * alloc/free : devm_kzalloc(), devm_kzfree() * IO region : devm_request_region(), devm_release_region() * IRQ : devm_request_irq(), devm_free_irq() * DMA : dmam_alloc_coherent(), dmam_free_coherent(), dmam_declare_coherent_memory(), dmam_pool_create(), dmam_pool_destroy() * PCI : pcim_enable_device(), pcim_pin_device(), pci_is_managed() * iomap : devm_ioport_map(), devm_ioport_unmap(), devm_ioremap(), devm_ioremap_nocache(), devm_iounmap(), pcim_iomap_table(), pcim_iomap(), pcim_iounmap() Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'kernel/irq')
-rw-r--r--kernel/irq/manage.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 8b961adc3bd2..c4b7ed1cebf7 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -482,3 +482,89 @@ int request_irq(unsigned int irq, irq_handler_t handler,
return retval;
}
EXPORT_SYMBOL(request_irq);
+
+/*
+ * Device resource management aware IRQ request/free implementation.
+ */
+struct irq_devres {
+ unsigned int irq;
+ void *dev_id;
+};
+
+static void devm_irq_release(struct device *dev, void *res)
+{
+ struct irq_devres *this = res;
+
+ free_irq(this->irq, this->dev_id);
+}
+
+static int devm_irq_match(struct device *dev, void *res, void *data)
+{
+ struct irq_devres *this = res, *match = data;
+
+ return this->irq == match->irq && this->dev_id == match->dev_id;
+}
+
+/**
+ * devm_request_irq - allocate an interrupt line for a managed device
+ * @dev: device to request interrupt for
+ * @irq: Interrupt line to allocate
+ * @handler: Function to be called when the IRQ occurs
+ * @irqflags: Interrupt type flags
+ * @devname: An ascii name for the claiming device
+ * @dev_id: A cookie passed back to the handler function
+ *
+ * Except for the extra @dev argument, this function takes the
+ * same arguments and performs the same function as
+ * request_irq(). IRQs requested with this function will be
+ * automatically freed on driver detach.
+ *
+ * If an IRQ allocated with this function needs to be freed
+ * separately, dev_free_irq() must be used.
+ */
+int devm_request_irq(struct device *dev, unsigned int irq,
+ irq_handler_t handler, unsigned long irqflags,
+ const char *devname, void *dev_id)
+{
+ struct irq_devres *dr;
+ int rc;
+
+ dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
+ GFP_KERNEL);
+ if (!dr)
+ return -ENOMEM;
+
+ rc = request_irq(irq, handler, irqflags, devname, dev_id);
+ if (rc) {
+ kfree(dr);
+ return rc;
+ }
+
+ dr->irq = irq;
+ dr->dev_id = dev_id;
+ devres_add(dev, dr);
+
+ return 0;
+}
+EXPORT_SYMBOL(devm_request_irq);
+
+/**
+ * devm_free_irq - free an interrupt
+ * @dev: device to free interrupt for
+ * @irq: Interrupt line to free
+ * @dev_id: Device identity to free
+ *
+ * Except for the extra @dev argument, this function takes the
+ * same arguments and performs the same function as free_irq().
+ * This function instead of free_irq() should be used to manually
+ * free IRQs allocated with dev_request_irq().
+ */
+void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id)
+{
+ struct irq_devres match_data = { irq, dev_id };
+
+ free_irq(irq, dev_id);
+ WARN_ON(devres_destroy(dev, devm_irq_release, devm_irq_match,
+ &match_data));
+}
+EXPORT_SYMBOL(devm_free_irq);
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