1 files changed, 143 insertions, 92 deletions

diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c
index 424bb3b666db..0e38330271d5 100644
--- a/drivers/usb/gadget/function/f_ncm.c
+++ b/drivers/usb/gadget/function/f_ncm.c
@@ -11,14 +11,17 @@
  * Copyright (C) 2008 Nokia Corporation
  */
 
+#include <linux/cleanup.h>
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/device.h>
 #include <linux/etherdevice.h>
 #include <linux/crc32.h>
+#include <linux/string_choices.h>
 
 #include <linux/usb/cdc.h>
+#include <linux/usb/gadget.h>
 
 #include "u_ether.h"
 #include "u_ether_configfs.h"
@@ -80,21 +83,6 @@ static inline struct f_ncm *func_to_ncm(struct usb_function *f)
 	return container_of(f, struct f_ncm, port.func);
 }
 
-/* peak (theoretical) bulk transfer rate in bits-per-second */
-static inline unsigned ncm_bitrate(struct usb_gadget *g)
-{
-	if (!g)
-		return 0;
-	else if (gadget_is_superspeed(g) && g->speed >= USB_SPEED_SUPER_PLUS)
-		return 4250000000U;
-	else if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
-		return 3750000000U;
-	else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
-		return 13 * 512 * 8 * 1000 * 8;
-	else
-		return 19 *  64 * 1 * 1000 * 8;
-}
-
 /*-------------------------------------------------------------------------*/
 
 /*
@@ -118,6 +106,16 @@ static inline unsigned ncm_bitrate(struct usb_gadget *g)
 /* Delay for the transmit to wait before sending an unfilled NTB frame. */
 #define TX_TIMEOUT_NSECS	300000
 
+/*
+ * Although max mtu as dictated by u_ether is 15412 bytes, setting
+ * max_segment_size to 15426 would not be efficient. If user chooses segment
+ * size to be (>= 8192), then we can't aggregate more than one buffer in each
+ * NTB (assuming each packet coming from network layer is >= 8192 bytes) as ep
+ * maxpacket limit is 16384. So let max_segment_size be limited to 8000 to allow
+ * at least 2 packets to be aggregated reducing wastage of NTB buffer space
+ */
+#define MAX_DATAGRAM_SIZE	8000
+
 #define FORMATS_SUPPORTED	(USB_CDC_NCM_NTB16_SUPPORTED |	\
 				 USB_CDC_NCM_NTB32_SUPPORTED)
 
@@ -194,7 +192,6 @@ static struct usb_cdc_ether_desc ecm_desc = {
 	/* this descriptor actually adds value, surprise! */
 	/* .iMACAddress = DYNAMIC */
 	.bmEthernetStatistics =	cpu_to_le32(0), /* no statistics */
-	.wMaxSegmentSize =	cpu_to_le16(ETH_FRAME_LEN),
 	.wNumberMCFilters =	cpu_to_le16(0),
 	.bNumberPowerFilters =	0,
 };
@@ -564,7 +561,7 @@ static void ncm_do_notify(struct f_ncm *ncm)
 		req->length = sizeof *event;
 
 		DBG(cdev, "notify connect %s\n",
-				ncm->is_open ? "true" : "false");
+				str_true_false(ncm->is_open));
 		ncm->notify_state = NCM_NOTIFY_NONE;
 		break;
 
@@ -576,10 +573,10 @@ static void ncm_do_notify(struct f_ncm *ncm)
 
 		/* SPEED_CHANGE data is up/down speeds in bits/sec */
 		data = req->buf + sizeof *event;
-		data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
+		data[0] = cpu_to_le32(gether_bitrate(cdev->gadget));
 		data[1] = data[0];
 
-		DBG(cdev, "notify speed %u\n", ncm_bitrate(cdev->gadget));
+		DBG(cdev, "notify speed %u\n", gether_bitrate(cdev->gadget));
 		ncm->notify_state = NCM_NOTIFY_CONNECT;
 		break;
 	}
@@ -884,7 +881,7 @@ static int ncm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 		if (alt > 1)
 			goto fail;
 
-		if (ncm->port.in_ep->enabled) {
+		if (ncm->netdev) {
 			DBG(cdev, "reset ncm\n");
 			ncm->netdev = NULL;
 			gether_disconnect(&ncm->port);
@@ -1171,7 +1168,8 @@ static int ncm_unwrap_ntb(struct gether *port,
 			  struct sk_buff_head *list)
 {
 	struct f_ncm	*ncm = func_to_ncm(&port->func);
-	__le16		*tmp = (void *) skb->data;
+	unsigned char	*ntb_ptr = skb->data;
+	__le16		*tmp;
 	unsigned	index, index2;
 	int		ndp_index;
 	unsigned	dg_len, dg_len2;
@@ -1180,10 +1178,18 @@ static int ncm_unwrap_ntb(struct gether *port,
 	struct sk_buff	*skb2;
 	int		ret = -EINVAL;
 	unsigned	ntb_max = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
-	unsigned	frame_max = le16_to_cpu(ecm_desc.wMaxSegmentSize);
+	unsigned	frame_max;
 	const struct ndp_parser_opts *opts = ncm->parser_opts;
 	unsigned	crc_len = ncm->is_crc ? sizeof(uint32_t) : 0;
 	int		dgram_counter;
+	int		to_process = skb->len;
+	struct f_ncm_opts *ncm_opts;
+
+	ncm_opts = container_of(port->func.fi, struct f_ncm_opts, func_inst);
+	frame_max = ncm_opts->max_segment_size;
+
+parse_ntb:
+	tmp = (__le16 *)ntb_ptr;
 
 	/* dwSignature */
 	if (get_unaligned_le32(tmp) != opts->nth_sign) {
@@ -1230,7 +1236,7 @@ static int ncm_unwrap_ntb(struct gether *port,
 		 * walk through NDP
 		 * dwSignature
 		 */
-		tmp = (void *)(skb->data + ndp_index);
+		tmp = (__le16 *)(ntb_ptr + ndp_index);
 		if (get_unaligned_le32(tmp) != ncm->ndp_sign) {
 			INFO(port->func.config->cdev, "Wrong NDP SIGN\n");
 			goto err;
@@ -1287,11 +1293,11 @@ static int ncm_unwrap_ntb(struct gether *port,
 			if (ncm->is_crc) {
 				uint32_t crc, crc2;
 
-				crc = get_unaligned_le32(skb->data +
+				crc = get_unaligned_le32(ntb_ptr +
 							 index + dg_len -
 							 crc_len);
 				crc2 = ~crc32_le(~0,
-						 skb->data + index,
+						 ntb_ptr + index,
 						 dg_len - crc_len);
 				if (crc != crc2) {
 					INFO(port->func.config->cdev,
@@ -1318,7 +1324,7 @@ static int ncm_unwrap_ntb(struct gether *port,
 							 dg_len - crc_len);
 			if (skb2 == NULL)
 				goto err;
-			skb_put_data(skb2, skb->data + index,
+			skb_put_data(skb2, ntb_ptr + index,
 				     dg_len - crc_len);
 
 			skb_queue_tail(list, skb2);
@@ -1331,10 +1337,25 @@ static int ncm_unwrap_ntb(struct gether *port,
 		} while (ndp_len > 2 * (opts->dgram_item_len * 2));
 	} while (ndp_index);
 
-	dev_consume_skb_any(skb);
-
 	VDBG(port->func.config->cdev,
 	     "Parsed NTB with %d frames\n", dgram_counter);
+
+	to_process -= block_len;
+
+	/*
+	 * Windows NCM driver avoids USB ZLPs by adding a 1-byte
+	 * zero pad as needed.
+	 */
+	if (to_process == 1 &&
+	    (*(unsigned char *)(ntb_ptr + block_len) == 0x00)) {
+		to_process--;
+	} else if ((to_process > 0) && (block_len != 0)) {
+		ntb_ptr = (unsigned char *)(ntb_ptr + block_len);
+		goto parse_ntb;
+	}
+
+	dev_consume_skb_any(skb);
+
 	return 0;
 err:
 	skb_queue_purge(list);
@@ -1349,7 +1370,7 @@ static void ncm_disable(struct usb_function *f)
 
 	DBG(cdev, "ncm deactivated\n");
 
-	if (ncm->port.in_ep->enabled) {
+	if (ncm->netdev) {
 		ncm->netdev = NULL;
 		gether_disconnect(&ncm->port);
 	}
@@ -1413,46 +1434,44 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
 	struct usb_composite_dev *cdev = c->cdev;
 	struct f_ncm		*ncm = func_to_ncm(f);
 	struct usb_string	*us;
-	int			status;
+	int			status = 0;
 	struct usb_ep		*ep;
 	struct f_ncm_opts	*ncm_opts;
 
+	struct usb_os_desc_table	*os_desc_table __free(kfree) = NULL;
+	struct usb_request		*request __free(free_usb_request) = NULL;
+
 	if (!can_support_ecm(cdev->gadget))
 		return -EINVAL;
 
 	ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);
 
 	if (cdev->use_os_string) {
-		f->os_desc_table = kzalloc(sizeof(*f->os_desc_table),
-					   GFP_KERNEL);
-		if (!f->os_desc_table)
+		os_desc_table = kzalloc(sizeof(*os_desc_table), GFP_KERNEL);
+		if (!os_desc_table)
 			return -ENOMEM;
-		f->os_desc_n = 1;
-		f->os_desc_table[0].os_desc = &ncm_opts->ncm_os_desc;
 	}
 
-	/*
-	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
-	 * configurations are bound in sequence with list_for_each_entry,
-	 * in each configuration its functions are bound in sequence
-	 * with list_for_each_entry, so we assume no race condition
-	 * with regard to ncm_opts->bound access
-	 */
+	mutex_lock(&ncm_opts->lock);
+	gether_set_gadget(ncm_opts->net, cdev->gadget);
 	if (!ncm_opts->bound) {
-		mutex_lock(&ncm_opts->lock);
-		gether_set_gadget(ncm_opts->net, cdev->gadget);
+		ncm_opts->net->mtu = (ncm_opts->max_segment_size - ETH_HLEN);
 		status = gether_register_netdev(ncm_opts->net);
-		mutex_unlock(&ncm_opts->lock);
-		if (status)
-			goto fail;
-		ncm_opts->bound = true;
 	}
+	mutex_unlock(&ncm_opts->lock);
+
+	if (status)
+		return status;
+
+	ncm_opts->bound = true;
+
+	ncm_string_defs[1].s = ncm->ethaddr;
+
 	us = usb_gstrings_attach(cdev, ncm_strings,
 				 ARRAY_SIZE(ncm_string_defs));
-	if (IS_ERR(us)) {
-		status = PTR_ERR(us);
-		goto fail;
-	}
+	if (IS_ERR(us))
+		return PTR_ERR(us);
+
 	ncm_control_intf.iInterface = us[STRING_CTRL_IDX].id;
 	ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX].id;
 	ncm_data_intf.iInterface = us[STRING_DATA_IDX].id;
@@ -1462,55 +1481,49 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
 	/* allocate instance-specific interface IDs */
 	status = usb_interface_id(c, f);
 	if (status < 0)
-		goto fail;
+		return status;
 	ncm->ctrl_id = status;
 	ncm_iad_desc.bFirstInterface = status;
 
 	ncm_control_intf.bInterfaceNumber = status;
 	ncm_union_desc.bMasterInterface0 = status;
 
-	if (cdev->use_os_string)
-		f->os_desc_table[0].if_id =
-			ncm_iad_desc.bFirstInterface;
-
 	status = usb_interface_id(c, f);
 	if (status < 0)
-		goto fail;
+		return status;
 	ncm->data_id = status;
 
 	ncm_data_nop_intf.bInterfaceNumber = status;
 	ncm_data_intf.bInterfaceNumber = status;
 	ncm_union_desc.bSlaveInterface0 = status;
 
-	status = -ENODEV;
+	ecm_desc.wMaxSegmentSize = cpu_to_le16(ncm_opts->max_segment_size);
 
 	/* allocate instance-specific endpoints */
 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_in_desc);
 	if (!ep)
-		goto fail;
+		return -ENODEV;
 	ncm->port.in_ep = ep;
 
 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_out_desc);
 	if (!ep)
-		goto fail;
+		return -ENODEV;
 	ncm->port.out_ep = ep;
 
 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_notify_desc);
 	if (!ep)
-		goto fail;
+		return -ENODEV;
 	ncm->notify = ep;
 
-	status = -ENOMEM;
-
 	/* allocate notification request and buffer */
-	ncm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
-	if (!ncm->notify_req)
-		goto fail;
-	ncm->notify_req->buf = kmalloc(NCM_STATUS_BYTECOUNT, GFP_KERNEL);
-	if (!ncm->notify_req->buf)
-		goto fail;
-	ncm->notify_req->context = ncm;
-	ncm->notify_req->complete = ncm_notify_complete;
+	request = usb_ep_alloc_request(ep, GFP_KERNEL);
+	if (!request)
+		return -ENOMEM;
+	request->buf = kmalloc(NCM_STATUS_BYTECOUNT, GFP_KERNEL);
+	if (!request->buf)
+		return -ENOMEM;
+	request->context = ncm;
+	request->complete = ncm_notify_complete;
 
 	/*
 	 * support all relevant hardware speeds... we expect that when
@@ -1530,7 +1543,7 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
 	status = usb_assign_descriptors(f, ncm_fs_function, ncm_hs_function,
 			ncm_ss_function, ncm_ss_function);
 	if (status)
-		goto fail;
+		return status;
 
 	/*
 	 * NOTE:  all that is done without knowing or caring about
@@ -1541,28 +1554,20 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
 	ncm->port.open = ncm_open;
 	ncm->port.close = ncm_close;
 
-	hrtimer_init(&ncm->task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
-	ncm->task_timer.function = ncm_tx_timeout;
+	hrtimer_setup(&ncm->task_timer, ncm_tx_timeout, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
 
-	DBG(cdev, "CDC Network: %s speed IN/%s OUT/%s NOTIFY/%s\n",
-			gadget_is_superspeed(c->cdev->gadget) ? "super" :
-			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+	if (cdev->use_os_string) {
+		os_desc_table[0].os_desc = &ncm_opts->ncm_os_desc;
+		os_desc_table[0].if_id = ncm_iad_desc.bFirstInterface;
+		f->os_desc_table = no_free_ptr(os_desc_table);
+		f->os_desc_n = 1;
+	}
+	ncm->notify_req = no_free_ptr(request);
+
+	DBG(cdev, "CDC Network: IN/%s OUT/%s NOTIFY/%s\n",
 			ncm->port.in_ep->name, ncm->port.out_ep->name,
 			ncm->notify->name);
 	return 0;
-
-fail:
-	kfree(f->os_desc_table);
-	f->os_desc_n = 0;
-
-	if (ncm->notify_req) {
-		kfree(ncm->notify_req->buf);
-		usb_ep_free_request(ncm->notify, ncm->notify_req);
-	}
-
-	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
-
-	return status;
 }
 
 static inline struct f_ncm_opts *to_f_ncm_opts(struct config_item *item)
@@ -1586,11 +1591,56 @@ USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ncm);
 /* f_ncm_opts_ifname */
 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ncm);
 
+static ssize_t ncm_opts_max_segment_size_show(struct config_item *item,
+					      char *page)
+{
+	struct f_ncm_opts *opts = to_f_ncm_opts(item);
+	u16 segment_size;
+
+	mutex_lock(&opts->lock);
+	segment_size = opts->max_segment_size;
+	mutex_unlock(&opts->lock);
+
+	return sysfs_emit(page, "%u\n", segment_size);
+}
+
+static ssize_t ncm_opts_max_segment_size_store(struct config_item *item,
+					       const char *page, size_t len)
+{
+	struct f_ncm_opts *opts = to_f_ncm_opts(item);
+	u16 segment_size;
+	int ret;
+
+	mutex_lock(&opts->lock);
+	if (opts->refcnt) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	ret = kstrtou16(page, 0, &segment_size);
+	if (ret)
+		goto out;
+
+	if (segment_size > MAX_DATAGRAM_SIZE) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	opts->max_segment_size = segment_size;
+	ret = len;
+out:
+	mutex_unlock(&opts->lock);
+	return ret;
+}
+
+CONFIGFS_ATTR(ncm_opts_, max_segment_size);
+
 static struct configfs_attribute *ncm_attrs[] = {
 	&ncm_opts_attr_dev_addr,
 	&ncm_opts_attr_host_addr,
 	&ncm_opts_attr_qmult,
 	&ncm_opts_attr_ifname,
+	&ncm_opts_attr_max_segment_size,
 	NULL,
 };
 
@@ -1633,6 +1683,7 @@ static struct usb_function_instance *ncm_alloc_inst(void)
 		kfree(opts);
 		return ERR_CAST(net);
 	}
+	opts->max_segment_size = ETH_FRAME_LEN;
 	INIT_LIST_HEAD(&opts->ncm_os_desc.ext_prop);
 
 	descs[0] = &opts->ncm_os_desc;
@@ -1710,7 +1761,6 @@ static struct usb_function *ncm_alloc(struct usb_function_instance *fi)
 		mutex_unlock(&opts->lock);
 		return ERR_PTR(-EINVAL);
 	}
-	ncm_string_defs[STRING_MAC_IDX].s = ncm->ethaddr;
 
 	spin_lock_init(&ncm->lock);
 	ncm_reset_values(ncm);
@@ -1736,5 +1786,6 @@ static struct usb_function *ncm_alloc(struct usb_function_instance *fi)
 }
 
 DECLARE_USB_FUNCTION_INIT(ncm, ncm_alloc_inst, ncm_alloc);
+MODULE_DESCRIPTION("USB CDC Network (NCM) link function driver");
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Yauheni Kaliuta");