Attachment 606684 Details for Bug 842275 – backport of upstream patch

[patch] backport of upstream patch

hans.patch (text/plain), 8.98 KB, created by Don Zickus on 2012-08-23 19:00:27 UTC

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Creator: Don Zickus

Created: 2012-08-23 19:00:27 UTC

Size: 8.98 KB

patch

obsolete

>commit 3d97ff63f8997761f12c8fbe8082996c6eeaba1a
>Author: Hans de Goede <hdegoede@redhat.com>
>Date:   Wed Jul 4 09:18:03 2012 +0200
>
>    usbdevfs: Use scatter-gather lists for large bulk transfers
>    
>    When using urb->transfer_buffer we need to allocate physical contiguous buffers
>    for the entire transfer, which is pretty much guaranteed to fail with large
>    transfers.
>    
>    Currently userspace works around this by breaking large transfers into multiple
>    urbs. For large bulk transfers this leads to all kind of complications.
>    
>    This patch makes it possible for userspace to reliable submit large bulk
>    transfers to scatter-gather capable host controllers in one go, by using a
>    scatterlist to break the transfer up in managable chunks.
>    
>    Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>    Acked-by: Alan Stern <stern@rowland.harvard.edu>
>    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
>diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
>index 0b387c1..ebb8a9d 100644
>--- a/drivers/usb/core/devio.c
>+++ b/drivers/usb/core/devio.c
>@@ -47,6 +47,7 @@
> #include <linux/notifier.h>
> #include <linux/security.h>
> #include <linux/user_namespace.h>
>+#include <linux/scatterlist.h>
> #include <asm/uaccess.h>
> #include <asm/byteorder.h>
> #include <linux/moduleparam.h>
>@@ -55,6 +56,7 @@
> 
> #define USB_MAXBUS			64
> #define USB_DEVICE_MAX			USB_MAXBUS * 128
>+#define USB_SG_SIZE			16384 /* split-size for large txs */
> 
> /* Mutual exclusion for removal, open, and release */
> DEFINE_MUTEX(usbfs_mutex);
>@@ -285,9 +287,16 @@ static struct async *alloc_async(unsigned int numisoframes)
> 
> static void free_async(struct async *as)
> {
>+	int i;
>+
> 	put_pid(as->pid);
> 	if (as->cred)
> 		put_cred(as->cred);
>+	for (i = 0; i < as->urb->num_sgs; i++) {
>+		if (sg_page(&as->urb->sg[i]))
>+			kfree(sg_virt(&as->urb->sg[i]));
>+	}
>+	kfree(as->urb->sg);
> 	kfree(as->urb->transfer_buffer);
> 	kfree(as->urb->setup_packet);
> 	usb_free_urb(as->urb);
>@@ -388,6 +397,53 @@ static void snoop_urb(struct usb_device *udev,
> 	}
> }
> 
>+static void snoop_urb_data(struct urb *urb, unsigned len)
>+{
>+	int i, size;
>+
>+	if (!usbfs_snoop)
>+		return;
>+
>+	if (urb->num_sgs == 0) {
>+		print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_NONE, 32, 1,
>+			urb->transfer_buffer, len, 1);
>+		return;
>+	}
>+
>+	for (i = 0; i < urb->num_sgs && len; i++) {
>+		size = (len > USB_SG_SIZE) ? USB_SG_SIZE : len;
>+		print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_NONE, 32, 1,
>+			sg_virt(&urb->sg[i]), size, 1);
>+		len -= size;
>+	}
>+}
>+
>+static int copy_urb_data_to_user(u8 __user *userbuffer, struct urb *urb)
>+{
>+	unsigned i, len, size;
>+
>+	if (urb->number_of_packets > 0)		/* Isochronous */
>+		len = urb->transfer_buffer_length;
>+	else					/* Non-Isoc */
>+		len = urb->actual_length;
>+
>+	if (urb->num_sgs == 0) {
>+		if (copy_to_user(userbuffer, urb->transfer_buffer, len))
>+			return -EFAULT;
>+		return 0;
>+	}
>+
>+	for (i = 0; i < urb->num_sgs && len; i++) {
>+		size = (len > USB_SG_SIZE) ? USB_SG_SIZE : len;
>+		if (copy_to_user(userbuffer, sg_virt(&urb->sg[i]), size))
>+			return -EFAULT;
>+		userbuffer += size;
>+		len -= size;
>+	}
>+
>+	return 0;
>+}
>+
> #define AS_CONTINUATION	1
> #define AS_UNLINK	2
> 
>@@ -454,9 +510,10 @@ static void async_completed(struct urb *urb)
> 	}
> 	snoop(&urb->dev->dev, "urb complete\n");
> 	snoop_urb(urb->dev, as->userurb, urb->pipe, urb->actual_length,
>-			as->status, COMPLETE,
>-			((urb->transfer_flags & URB_DIR_MASK) == USB_DIR_OUT) ?
>-				NULL : urb->transfer_buffer, urb->actual_length);
>+			as->status, COMPLETE, NULL, 0);
>+	if ((urb->transfer_flags & URB_DIR_MASK) == USB_DIR_IN)
>+		snoop_urb_data(urb, urb->actual_length);
>+
> 	if (as->status < 0 && as->bulk_addr && as->status != -ECONNRESET &&
> 			as->status != -ENOENT)
> 		cancel_bulk_urbs(ps, as->bulk_addr);
>@@ -1114,8 +1171,8 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
> 	struct async *as = NULL;
> 	struct usb_ctrlrequest *dr = NULL;
> 	unsigned int u, totlen, isofrmlen;
>-	int ret, ifnum = -1;
>-	int is_in;
>+	int i, ret, is_in, num_sgs = 0, ifnum = -1;
>+	void *buf;
> 
> 	if (uurb->flags & ~(USBDEVFS_URB_ISO_ASAP |
> 				USBDEVFS_URB_SHORT_NOT_OK |
>@@ -1199,6 +1256,9 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
> 			goto interrupt_urb;
> 		}
> 		uurb->number_of_packets = 0;
>+		num_sgs = DIV_ROUND_UP(uurb->buffer_length, USB_SG_SIZE);
>+		if (num_sgs == 1 || num_sgs > ps->dev->bus->sg_tablesize)
>+			num_sgs = 0;
> 		break;
> 
> 	case USBDEVFS_URB_TYPE_INTERRUPT:
>@@ -1255,26 +1315,67 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
> 		ret = -ENOMEM;
> 		goto error;
> 	}
>-	u += sizeof(struct async) + sizeof(struct urb) + uurb->buffer_length;
>+
>+	u += sizeof(struct async) + sizeof(struct urb) + uurb->buffer_length +
>+	     num_sgs * sizeof(struct scatterlist);
> 	ret = usbfs_increase_memory_usage(u);
> 	if (ret)
> 		goto error;
> 	as->mem_usage = u;
> 
>-	if (uurb->buffer_length > 0) {
>+	if (num_sgs) {
>+		as->urb->sg = kmalloc(num_sgs * sizeof(struct scatterlist),
>+				      GFP_KERNEL);
>+		if (!as->urb->sg) {
>+			ret = -ENOMEM;
>+			goto error;
>+		}
>+		as->urb->num_sgs = num_sgs;
>+		sg_init_table(as->urb->sg, as->urb->num_sgs);
>+
>+		totlen = uurb->buffer_length;
>+		for (i = 0; i < as->urb->num_sgs; i++) {
>+			u = (totlen > USB_SG_SIZE) ? USB_SG_SIZE : totlen;
>+			buf = kmalloc(u, GFP_KERNEL);
>+			if (!buf) {
>+				ret = -ENOMEM;
>+				goto error;
>+			}
>+			sg_set_buf(&as->urb->sg[i], buf, u);
>+
>+			if (!is_in) {
>+				if (copy_from_user(buf, uurb->buffer, u)) {
>+					ret = -EFAULT;
>+					goto error;
>+				}
>+			}
>+			totlen -= u;
>+		}
>+	} else if (uurb->buffer_length > 0) {
> 		as->urb->transfer_buffer = kmalloc(uurb->buffer_length,
> 				GFP_KERNEL);
> 		if (!as->urb->transfer_buffer) {
> 			ret = -ENOMEM;
> 			goto error;
> 		}
>-		/* Isochronous input data may end up being discontiguous
>-		 * if some of the packets are short.  Clear the buffer so
>-		 * that the gaps don't leak kernel data to userspace.
>-		 */
>-		if (is_in && uurb->type == USBDEVFS_URB_TYPE_ISO)
>+
>+		if (!is_in) {
>+			if (copy_from_user(as->urb->transfer_buffer,
>+					   uurb->buffer,
>+					   uurb->buffer_length)) {
>+				ret = -EFAULT;
>+				goto error;
>+			}
>+		} else if (uurb->type == USBDEVFS_URB_TYPE_ISO) {
>+			/*
>+			 * Isochronous input data may end up being
>+			 * discontiguous if some of the packets are short.
>+			 * Clear the buffer so that the gaps don't leak
>+			 * kernel data to userspace.
>+			 */
> 			memset(as->urb->transfer_buffer, 0,
> 					uurb->buffer_length);
>+		}
> 	}
> 	as->urb->dev = ps->dev;
> 	as->urb->pipe = (uurb->type << 30) |
>@@ -1328,17 +1429,12 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
> 	as->pid = get_pid(task_pid(current));
> 	as->cred = get_current_cred();
> 	security_task_getsecid(current, &as->secid);
>-	if (!is_in && uurb->buffer_length > 0) {
>-		if (copy_from_user(as->urb->transfer_buffer, uurb->buffer,
>-				uurb->buffer_length)) {
>-			ret = -EFAULT;
>-			goto error;
>-		}
>-	}
> 	snoop_urb(ps->dev, as->userurb, as->urb->pipe,
> 			as->urb->transfer_buffer_length, 0, SUBMIT,
>-			is_in ? NULL : as->urb->transfer_buffer,
>-				uurb->buffer_length);
>+			NULL, 0);
>+	if (!is_in)
>+		snoop_urb_data(as->urb, as->urb->transfer_buffer_length);
>+
> 	async_newpending(as);
> 
> 	if (usb_endpoint_xfer_bulk(&ep->desc)) {
>@@ -1433,11 +1529,7 @@ static int processcompl(struct async *as, void __user * __user *arg)
> 	unsigned int i;
> 
> 	if (as->userbuffer && urb->actual_length) {
>-		if (urb->number_of_packets > 0)		/* Isochronous */
>-			i = urb->transfer_buffer_length;
>-		else					/* Non-Isoc */
>-			i = urb->actual_length;
>-		if (copy_to_user(as->userbuffer, urb->transfer_buffer, i))
>+		if (copy_urb_data_to_user(as->userbuffer, urb))
> 			goto err_out;
> 	}
> 	if (put_user(as->status, &userurb->status))
>@@ -1605,11 +1697,7 @@ static int processcompl_compat(struct async *as, void __user * __user *arg)
> 	unsigned int i;
> 
> 	if (as->userbuffer && urb->actual_length) {
>-		if (urb->number_of_packets > 0)		/* Isochronous */
>-			i = urb->transfer_buffer_length;
>-		else					/* Non-Isoc */
>-			i = urb->actual_length;
>-		if (copy_to_user(as->userbuffer, urb->transfer_buffer, i))
>+		if (copy_urb_data_to_user(as->userbuffer, urb))
> 			return -EFAULT;
> 	}
> 	if (put_user(as->status, &userurb->status))
>@@ -1831,6 +1919,8 @@ static int proc_get_capabilities(struct dev_state *ps, void __user *arg)
> 	caps = USBDEVFS_CAP_ZERO_PACKET | USBDEVFS_CAP_NO_PACKET_SIZE_LIM;
> 	if (!ps->dev->bus->no_stop_on_short)
> 		caps |= USBDEVFS_CAP_BULK_CONTINUATION;
>+	if (ps->dev->bus->sg_tablesize)
>+		caps |= USBDEVFS_CAP_BULK_SCATTER_GATHER;
> 
> 	if (put_user(caps, (__u32 __user *)arg))
> 		return -EFAULT;
>diff --git a/include/linux/usbdevice_fs.h b/include/linux/usbdevice_fs.h
>index 07b2cea..3b74666 100644
>--- a/include/linux/usbdevice_fs.h
>+++ b/include/linux/usbdevice_fs.h
>@@ -129,6 +129,7 @@ struct usbdevfs_hub_portinfo {
> #define USBDEVFS_CAP_ZERO_PACKET		0x01
> #define USBDEVFS_CAP_BULK_CONTINUATION		0x02
> #define USBDEVFS_CAP_NO_PACKET_SIZE_LIM		0x04
>+#define USBDEVFS_CAP_BULK_SCATTER_GATHER	0x08
> 
> #ifdef __KERNEL__
> #ifdef CONFIG_COMPAT

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Attachments on bug 842275: 606684 | 606689