From: Bernie Thompson Date: Mon, 15 Feb 2010 14:45:55 +0000 (-0800) Subject: Staging: udlfb: pre-allocated urb list helpers X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=4a4854dd2049ddc066a162a0f843dc2a78481060;p=linux-beck.git 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 Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/udlfb/udlfb.c b/drivers/staging/udlfb/udlfb.c index 3306bba9df3d..592b1857924f 100644 --- a/drivers/staging/udlfb/udlfb.c +++ b/drivers/staging/udlfb/udlfb.c @@ -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 , " "Jaya Kumar "); MODULE_DESCRIPTION(DRIVER_VERSION); diff --git a/drivers/staging/udlfb/udlfb.h b/drivers/staging/udlfb/udlfb.h index 15f3d3a68364..13f992fe45f7 100644 --- a/drivers/staging/udlfb/udlfb.h +++ b/drivers/staging/udlfb/udlfb.h @@ -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