usb-core: create dev pool allocation

Have a device structure pool and provide apis usb_devpool_[get,put]

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Acked-by: Thomas Huth <thuth@linux.vnet.ibm.com>

2 files changed, 63 insertions, 0 deletions

diff --git a/lib/libusb/usb-core.c b/lib/libusb/usb-core.c
index 6e2de1f..b1e3449 100644
--- a/lib/libusb/usb-core.c
+++ b/lib/libusb/usb-core.c
@@ -10,6 +10,7 @@
  *     IBM Corporation - initial implementation
  *****************************************************************************/
 
+#include <string.h>
 #include "usb-core.h"
 
 #undef DEBUG
@@ -21,6 +22,65 @@
 #endif
 
 struct usb_hcd_ops *head;
+struct usb_dev *devpool;
+#define USB_DEVPOOL_SIZE 4096
+
+static struct usb_dev *usb_alloc_devpool(void)
+{
+	struct usb_dev *head, *curr, *prev;
+	unsigned int dev_count = 0, i;
+
+	head = SLOF_dma_alloc(USB_DEVPOOL_SIZE);
+	if (!head)
+		return NULL;
+
+	dev_count = USB_DEVPOOL_SIZE/sizeof(struct usb_dev);
+	dprintf("%s: %d number of devices\n", __func__, dev_count);
+	/* Although an array, link them*/
+	for (i = 0, curr = head, prev = NULL; i < dev_count; i++, curr++) {
+		if (prev)
+			prev->next = curr;
+		curr->next = NULL;
+		prev = curr;
+	}
+
+#ifdef DEBUG
+	for (i = 0, curr = head; curr; curr = curr->next)
+		printf("%s: %d dev %p\n", __func__, i++, curr);
+#endif
+
+	return head;
+}
+
+struct usb_dev *usb_devpool_get(void)
+{
+	struct usb_dev *new;
+
+	if (!devpool) {
+		devpool = usb_alloc_devpool();
+		if (!devpool)
+			return NULL;
+	}
+
+	new = devpool;
+	devpool = devpool->next;
+	memset(new, 0, sizeof(*new));
+	new->next = NULL;
+	return new;
+}
+
+void usb_devpool_put(struct usb_dev *dev)
+{
+	struct usb_dev *curr;
+	if (!dev && !devpool)
+		return;
+
+	curr = devpool;
+	while (curr->next)
+		curr = curr->next;
+	curr->next = dev;
+	dev->next = NULL;
+}
 
 #ifndef DEBUG
 #define validate_hcd_ops(dev) (dev && dev->hcidev && dev->hcidev->ops)
diff --git a/lib/libusb/usb-core.h b/lib/libusb/usb-core.h
index 1de15d6..cc9dbe9 100644
--- a/lib/libusb/usb-core.h
+++ b/lib/libusb/usb-core.h
@@ -61,6 +61,7 @@ struct usb_ep_descr {
 #define USB_DEV_EP_MAX 4
 
 struct usb_dev {
+	struct usb_dev     *next;
 	struct usb_hcd_dev *hcidev;
 	struct usb_pipe    *intr;
 	struct usb_pipe    *control;
@@ -133,5 +134,7 @@ extern struct usb_pipe *usb_get_pipe(struct usb_dev *dev, struct usb_ep_descr *e
 				char *buf, size_t len);
 extern void usb_put_pipe(struct usb_pipe *pipe);
 extern int usb_send_ctrl(struct usb_pipe *pipe, struct usb_dev_req *req, void *data);
+extern struct usb_dev *usb_devpool_get(void);
+extern void usb_devpool_put(struct usb_dev *);
 
 #endif