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path: root/drivers/dca/dca-core.c
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Diffstat (limited to 'drivers/dca/dca-core.c')
-rw-r--r--drivers/dca/dca-core.c131
1 files changed, 103 insertions, 28 deletions
diff --git a/drivers/dca/dca-core.c b/drivers/dca/dca-core.c
index bf5b92f86df7..ec249d2db633 100644
--- a/drivers/dca/dca-core.c
+++ b/drivers/dca/dca-core.c
@@ -28,13 +28,29 @@
#include <linux/device.h>
#include <linux/dca.h>
-MODULE_LICENSE("GPL");
+#define DCA_VERSION "1.4"
-/* For now we're assuming a single, global, DCA provider for the system. */
+MODULE_VERSION(DCA_VERSION);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Intel Corporation");
static DEFINE_SPINLOCK(dca_lock);
-static struct dca_provider *global_dca = NULL;
+static LIST_HEAD(dca_providers);
+
+static struct dca_provider *dca_find_provider_by_dev(struct device *dev)
+{
+ struct dca_provider *dca, *ret = NULL;
+
+ list_for_each_entry(dca, &dca_providers, node) {
+ if ((!dev) || (dca->ops->dev_managed(dca, dev))) {
+ ret = dca;
+ break;
+ }
+ }
+
+ return ret;
+}
/**
* dca_add_requester - add a dca client to the list
@@ -42,25 +58,39 @@ static struct dca_provider *global_dca = NULL;
*/
int dca_add_requester(struct device *dev)
{
- int err, slot;
+ struct dca_provider *dca;
+ int err, slot = -ENODEV;
- if (!global_dca)
- return -ENODEV;
+ if (!dev)
+ return -EFAULT;
spin_lock(&dca_lock);
- slot = global_dca->ops->add_requester(global_dca, dev);
- spin_unlock(&dca_lock);
- if (slot < 0)
+
+ /* check if the requester has not been added already */
+ dca = dca_find_provider_by_dev(dev);
+ if (dca) {
+ spin_unlock(&dca_lock);
+ return -EEXIST;
+ }
+
+ list_for_each_entry(dca, &dca_providers, node) {
+ slot = dca->ops->add_requester(dca, dev);
+ if (slot >= 0)
+ break;
+ }
+ if (slot < 0) {
+ spin_unlock(&dca_lock);
return slot;
+ }
- err = dca_sysfs_add_req(global_dca, dev, slot);
+ err = dca_sysfs_add_req(dca, dev, slot);
if (err) {
- spin_lock(&dca_lock);
- global_dca->ops->remove_requester(global_dca, dev);
+ dca->ops->remove_requester(dca, dev);
spin_unlock(&dca_lock);
return err;
}
+ spin_unlock(&dca_lock);
return 0;
}
EXPORT_SYMBOL_GPL(dca_add_requester);
@@ -71,30 +101,78 @@ EXPORT_SYMBOL_GPL(dca_add_requester);
*/
int dca_remove_requester(struct device *dev)
{
+ struct dca_provider *dca;
int slot;
- if (!global_dca)
- return -ENODEV;
+
+ if (!dev)
+ return -EFAULT;
spin_lock(&dca_lock);
- slot = global_dca->ops->remove_requester(global_dca, dev);
- spin_unlock(&dca_lock);
- if (slot < 0)
+ dca = dca_find_provider_by_dev(dev);
+ if (!dca) {
+ spin_unlock(&dca_lock);
+ return -ENODEV;
+ }
+ slot = dca->ops->remove_requester(dca, dev);
+ if (slot < 0) {
+ spin_unlock(&dca_lock);
return slot;
+ }
- dca_sysfs_remove_req(global_dca, slot);
+ dca_sysfs_remove_req(dca, slot);
+
+ spin_unlock(&dca_lock);
return 0;
}
EXPORT_SYMBOL_GPL(dca_remove_requester);
/**
- * dca_get_tag - return the dca tag for the given cpu
+ * dca_common_get_tag - return the dca tag (serves both new and old api)
+ * @dev - the device that wants dca service
* @cpu - the cpuid as returned by get_cpu()
*/
-u8 dca_get_tag(int cpu)
+u8 dca_common_get_tag(struct device *dev, int cpu)
{
- if (!global_dca)
+ struct dca_provider *dca;
+ u8 tag;
+
+ spin_lock(&dca_lock);
+
+ dca = dca_find_provider_by_dev(dev);
+ if (!dca) {
+ spin_unlock(&dca_lock);
return -ENODEV;
- return global_dca->ops->get_tag(global_dca, cpu);
+ }
+ tag = dca->ops->get_tag(dca, dev, cpu);
+
+ spin_unlock(&dca_lock);
+ return tag;
+}
+
+/**
+ * dca3_get_tag - return the dca tag to the requester device
+ * for the given cpu (new api)
+ * @dev - the device that wants dca service
+ * @cpu - the cpuid as returned by get_cpu()
+ */
+u8 dca3_get_tag(struct device *dev, int cpu)
+{
+ if (!dev)
+ return -EFAULT;
+
+ return dca_common_get_tag(dev, cpu);
+}
+EXPORT_SYMBOL_GPL(dca3_get_tag);
+
+/**
+ * dca_get_tag - return the dca tag for the given cpu (old api)
+ * @cpu - the cpuid as returned by get_cpu()
+ */
+u8 dca_get_tag(int cpu)
+{
+ struct device *dev = NULL;
+
+ return dca_common_get_tag(dev, cpu);
}
EXPORT_SYMBOL_GPL(dca_get_tag);
@@ -140,12 +218,10 @@ int register_dca_provider(struct dca_provider *dca, struct device *dev)
{
int err;
- if (global_dca)
- return -EEXIST;
err = dca_sysfs_add_provider(dca, dev);
if (err)
return err;
- global_dca = dca;
+ list_add(&dca->node, &dca_providers);
blocking_notifier_call_chain(&dca_provider_chain,
DCA_PROVIDER_ADD, NULL);
return 0;
@@ -158,11 +234,9 @@ EXPORT_SYMBOL_GPL(register_dca_provider);
*/
void unregister_dca_provider(struct dca_provider *dca)
{
- if (!global_dca)
- return;
blocking_notifier_call_chain(&dca_provider_chain,
DCA_PROVIDER_REMOVE, NULL);
- global_dca = NULL;
+ list_del(&dca->node);
dca_sysfs_remove_provider(dca);
}
EXPORT_SYMBOL_GPL(unregister_dca_provider);
@@ -187,6 +261,7 @@ EXPORT_SYMBOL_GPL(dca_unregister_notify);
static int __init dca_init(void)
{
+ printk(KERN_ERR "dca service started, version %s\n", DCA_VERSION);
return dca_sysfs_init();
}