Staging: udlfb: improved rendering performance

Rework rendering for improved performance

Approx 10-20% gain avg across several "benchmarks": x11perf, gtkperf, glxgears
Moves from a single pre-alloc'd urb protected by a long-held mutex
To a list of (4) pre-alloc'd urbs which can be dispatched asynchonously

Improved rendering algorithm to hardware with lower CPU consumption,
fewer system memory accesses, and slightly higher compression.

Better scalability to multiple processors, especially with
multiple framebuffers active.
Signed-off-by: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/udlfb/udlfb.h

 #ifndef UDLFB_H
 #define UDLFB_H
 
-/* as libdlo */
-#define BUF_HIGH_WATER_MARK	1024
-#define BUF_SIZE		(64*1024)
+/*
+ * TODO: Propose standard fb.h ioctl for reporting damage,
+ * using _IOWR() and one of the existing area structs from fb.h
+ * Consider these ioctls deprecated, but they're still used by the
+ * DisplayLink X server as yet - need both to be modified in tandem
+ * when new ioctl(s) are ready.
+ */
+#define DLFB_IOCTL_RETURN_EDID	 0xAD
+#define DLFB_IOCTL_REPORT_DAMAGE 0xAA
+struct dloarea {
+	int x, y;
+	int w, h;
+	int x2, y2;
+};
 
 struct urb_node {
 	struct list_head entry;
@@ -23,30 +34,20 @@ struct urb_list {
 struct dlfb_data {
 	struct usb_device *udev;
 	struct device *gdev; /* &udev->dev */
-	struct usb_interface *interface;
-	struct urb *tx_urb, *ctrl_urb;
 	struct fb_info *info;
 	struct urb_list urbs;
 	struct kref kref;
-	char *buf;
-	char *bufend;
 	char *backing_buffer;
 	struct delayed_work deferred_work;
 	struct mutex fb_open_lock;
-	struct mutex bulk_mutex;
 	int fb_count;
 	atomic_t usb_active; /* 0 = update virtual buffer, but no usb traffic */
 	atomic_t lost_pixels; /* 1 = a render op failed. Need screen refresh */
 	atomic_t use_defio; /* 0 = rely on ioctls and blit/copy/fill rects */
 	char edid[128];
 	int sku_pixel_limit;
-	int screen_size;
-	int line_length;
-	struct completion done;
 	int base16;
-	int base16d;
 	int base8;
-	int base8d;
 	u32 pseudo_palette[256];
 	/* blit-only rendering path metrics, exposed through sysfs */
 	atomic_t bytes_rendered; /* raw pixel-bytes driver asked to render */
@@ -72,48 +73,24 @@ struct dlfb_data {
 #define GET_URB_TIMEOUT	HZ
 #define FREE_URB_TIMEOUT (HZ*2)
 
-static void dlfb_bulk_callback(struct urb *urb)
-{
-	struct dlfb_data *dev_info = urb->context;
-	complete(&dev_info->done);
-}
-
-static void dlfb_edid(struct dlfb_data *dev_info)
-{
-	int i;
-	int ret;
-	char rbuf[2];
-
-	for (i = 0; i < 128; i++) {
-		ret =
-		    usb_control_msg(dev_info->udev,
-				    usb_rcvctrlpipe(dev_info->udev, 0), (0x02),
-				    (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
-				    0);
-		dev_info->edid[i] = rbuf[1];
-	}
-
-}
-
-static int dlfb_bulk_msg(struct dlfb_data *dev_info, int len)
-{
-	int ret;
-
-	init_completion(&dev_info->done);
+#define BPP                     2
+#define MAX_CMD_PIXELS		255
 
-	dev_info->tx_urb->actual_length = 0;
-	dev_info->tx_urb->transfer_buffer_length = len;
+#define RLX_HEADER_BYTES	7
+#define MIN_RLX_PIX_BYTES       4
+#define MIN_RLX_CMD_BYTES	(RLX_HEADER_BYTES + MIN_RLX_PIX_BYTES)
 
-	ret = usb_submit_urb(dev_info->tx_urb, GFP_KERNEL);
-	if (!wait_for_completion_timeout(&dev_info->done, 1000)) {
-		usb_kill_urb(dev_info->tx_urb);
-		printk("usb timeout !!!\n");
-	}
+#define RLE_HEADER_BYTES	6
+#define MIN_RLE_PIX_BYTES	3
+#define MIN_RLE_CMD_BYTES	(RLE_HEADER_BYTES + MIN_RLE_PIX_BYTES)
 
-	return dev_info->tx_urb->actual_length;
-}
+#define RAW_HEADER_BYTES	6
+#define MIN_RAW_PIX_BYTES	2
+#define MIN_RAW_CMD_BYTES	(RAW_HEADER_BYTES + MIN_RAW_PIX_BYTES)
 
-#define dlfb_set_register insert_command
+/* remove these once align.h patch is taken into kernel */
+#define DL_ALIGN_UP(x, a) ALIGN(x, a)
+#define DL_ALIGN_DOWN(x, a) ALIGN(x-(a-1), a)
 
 /* remove once this gets added to sysfs.h */
 #define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store)