Staging: udlfb: pre-allocated urb list helpers

Add functions to pre-allocate and free usb bulk urbs for core render path.

Udlfb currently allocates a single urb, guarded by a mutex, that is a key
bottleneck. Because udlfb sends so much data, preallocation is most efficient.

Functions will be used by new rendering functions in later patches.

Signed-off-by: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Bernie Thompson 2010-02-15 06:45:55 -08:00 committed by Greg Kroah-Hartman
parent cc403dc67d
commit 4a4854dd20
2 changed files with 227 additions and 0 deletions

View File

@ -51,6 +51,13 @@ static struct usb_device_id id_table[] = {
};
MODULE_DEVICE_TABLE(usb, id_table);
/* dlfb keeps a list of urbs for efficient bulk transfers */
static void dlfb_urb_completion(struct urb *urb);
static struct urb *dlfb_get_urb(struct dlfb_data *dev);
static int dlfb_submit_urb(struct dlfb_data *dev, struct urb * urb, size_t len);
static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size);
static void dlfb_free_urb_list(struct dlfb_data *dev);
/*
* Inserts a specific DisplayLink controller command into the provided
* buffer.
@ -901,6 +908,21 @@ static int dlfb_release(struct fb_info *info, int user)
return 0;
}
/*
* Called when all client interfaces to start transactions have been disabled,
* and all references to our device instance (dlfb_data) are released.
* Every transaction must have a reference, so we know are fully spun down
*/
static void dlfb_delete(struct kref *kref)
{
struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
if (dev->backing_buffer)
vfree(dev->backing_buffer);
kfree(dev);
}
static int dlfb_blank(int blank_mode, struct fb_info *info)
{
struct dlfb_data *dev_info = info->par;
@ -974,6 +996,7 @@ static int dlfb_probe(struct usb_interface *interface,
mutex_init(&dev->bulk_mutex);
dev->udev = usbdev;
dev->gdev = &usbdev->dev; /* our generic struct device * */
dev->interface = interface;
usb_set_intfdata(interface, dev);
@ -1168,6 +1191,175 @@ static void __exit dlfb_exit(void)
module_init(dlfb_init);
module_exit(dlfb_exit);
static void dlfb_urb_completion(struct urb *urb)
{
struct urb_node *unode = urb->context;
struct dlfb_data *dev = unode->dev;
unsigned long flags;
/* sync/async unlink faults aren't errors */
if (urb->status) {
if (!(urb->status == -ENOENT ||
urb->status == -ECONNRESET ||
urb->status == -ESHUTDOWN)) {
dl_err("%s - nonzero write bulk status received: %d\n",
__func__, urb->status);
atomic_set(&dev->lost_pixels, 1);
}
}
urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
spin_lock_irqsave(&dev->urbs.lock, flags);
list_add_tail(&unode->entry, &dev->urbs.list);
dev->urbs.available++;
spin_unlock_irqrestore(&dev->urbs.lock, flags);
up(&dev->urbs.limit_sem);
}
static void dlfb_free_urb_list(struct dlfb_data *dev)
{
int count = dev->urbs.count;
struct list_head *node;
struct urb_node *unode;
struct urb *urb;
int ret;
unsigned long flags;
dl_notice("Waiting for completes and freeing all render urbs\n");
/* keep waiting and freeing, until we've got 'em all */
while (count--) {
/* Timeout means a memory leak and/or fault */
ret = down_timeout(&dev->urbs.limit_sem, FREE_URB_TIMEOUT);
if (ret) {
BUG_ON(ret);
break;
}
spin_lock_irqsave(&dev->urbs.lock, flags);
node = dev->urbs.list.next; /* have reserved one with sem */
list_del_init(node);
spin_unlock_irqrestore(&dev->urbs.lock, flags);
unode = list_entry(node, struct urb_node, entry);
urb = unode->urb;
/* Free each separately allocated piece */
usb_buffer_free(urb->dev, dev->urbs.size,
urb->transfer_buffer, urb->transfer_dma);
usb_free_urb(urb);
kfree(node);
}
kref_put(&dev->kref, dlfb_delete);
}
static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
{
int i = 0;
struct urb *urb;
struct urb_node *unode;
char *buf;
spin_lock_init(&dev->urbs.lock);
dev->urbs.size = size;
INIT_LIST_HEAD(&dev->urbs.list);
while (i < count) {
unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
if (!unode)
break;
unode->dev = dev;
urb = usb_alloc_urb(0, GFP_KERNEL);
if (!urb) {
kfree(unode);
break;
}
unode->urb = urb;
buf = usb_buffer_alloc(dev->udev, MAX_TRANSFER, GFP_KERNEL,
&urb->transfer_dma);
if (!buf) {
kfree(unode);
usb_free_urb(urb);
break;
}
/* urb->transfer_buffer_length set to actual before submit */
usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
buf, size, dlfb_urb_completion, unode);
urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
list_add_tail(&unode->entry, &dev->urbs.list);
i++;
}
sema_init(&dev->urbs.limit_sem, i);
dev->urbs.count = i;
dev->urbs.available = i;
kref_get(&dev->kref); /* released in free_render_urbs() */
dl_notice("allocated %d %d byte urbs \n", i, (int) size);
return i;
}
static struct urb *dlfb_get_urb(struct dlfb_data *dev)
{
int ret = 0;
struct list_head *entry;
struct urb_node *unode;
struct urb *urb = NULL;
unsigned long flags;
/* Wait for an in-flight buffer to complete and get re-queued */
ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
if (ret) {
atomic_set(&dev->lost_pixels, 1);
dl_err("wait for urb interrupted: %x\n", ret);
goto error;
}
spin_lock_irqsave(&dev->urbs.lock, flags);
BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
entry = dev->urbs.list.next;
list_del_init(entry);
dev->urbs.available--;
spin_unlock_irqrestore(&dev->urbs.lock, flags);
unode = list_entry(entry, struct urb_node, entry);
urb = unode->urb;
error:
return urb;
}
static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
{
int ret;
BUG_ON(len > dev->urbs.size);
urb->transfer_buffer_length = len; /* set to actual payload len */
ret = usb_submit_urb(urb, GFP_KERNEL);
if (ret) {
dlfb_urb_completion(urb); /* because no one else will */
atomic_set(&dev->lost_pixels, 1);
dl_err("usb_submit_urb error %x\n", ret);
}
return ret;
}
MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
"Jaya Kumar <jayakumar.lkml@gmail.com>");
MODULE_DESCRIPTION(DRIVER_VERSION);

View File

@ -5,16 +5,35 @@
#define BUF_HIGH_WATER_MARK 1024
#define BUF_SIZE (64*1024)
struct urb_node {
struct list_head entry;
struct dlfb_data *dev;
struct urb *urb;
};
struct urb_list {
struct list_head list;
spinlock_t lock;
struct semaphore limit_sem;
int available;
int count;
size_t size;
};
struct dlfb_data {
struct usb_device *udev;
struct device *gdev; /* &udev->dev */
struct usb_interface *interface;
struct urb *tx_urb, *ctrl_urb;
struct usb_ctrlrequest dr;
struct fb_info *info;
struct urb_list urbs;
struct kref kref;
char *buf;
char *bufend;
char *backing_buffer;
struct mutex bulk_mutex;
atomic_t lost_pixels; /* 1 = a render op failed. Need screen refresh */
char edid[128];
int screen_size;
int line_length;
@ -29,6 +48,14 @@ struct dlfb_data {
#define NR_USB_REQUEST_I2C_SUB_IO 0x02
#define NR_USB_REQUEST_CHANNEL 0x12
/* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
#define BULK_SIZE 512
#define MAX_TRANSFER (PAGE_SIZE*16 - BULK_SIZE)
#define WRITES_IN_FLIGHT (4)
#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;
@ -72,4 +99,12 @@ static int dlfb_bulk_msg(struct dlfb_data *dev_info, int len)
#define dlfb_set_register insert_command
#define dl_err(format, arg...) \
dev_err(dev->gdev, "dlfb: " format, ## arg)
#define dl_warn(format, arg...) \
dev_warn(dev->gdev, "dlfb: " format, ## arg)
#define dl_notice(format, arg...) \
dev_notice(dev->gdev, "dlfb: " format, ## arg)
#define dl_info(format, arg...) \
dev_info(dev->gdev, "dlfb: " format, ## arg)
#endif