Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:
 "Some highlights from this development cycle:

   1) Big refactoring of ipv6 route and neigh handling to support
      nexthop objects configurable as units from userspace. From David
      Ahern.

   2) Convert explored_states in BPF verifier into a hash table,
      significantly decreased state held for programs with bpf2bpf
      calls, from Alexei Starovoitov.

   3) Implement bpf_send_signal() helper, from Yonghong Song.

   4) Various classifier enhancements to mvpp2 driver, from Maxime
      Chevallier.

   5) Add aRFS support to hns3 driver, from Jian Shen.

   6) Fix use after free in inet frags by allocating fqdirs dynamically
      and reworking how rhashtable dismantle occurs, from Eric Dumazet.

   7) Add act_ctinfo packet classifier action, from Kevin
      Darbyshire-Bryant.

   8) Add TFO key backup infrastructure, from Jason Baron.

   9) Remove several old and unused ISDN drivers, from Arnd Bergmann.

  10) Add devlink notifications for flash update status to mlxsw driver,
      from Jiri Pirko.

  11) Lots of kTLS offload infrastructure fixes, from Jakub Kicinski.

  12) Add support for mv88e6250 DSA chips, from Rasmus Villemoes.

  13) Various enhancements to ipv6 flow label handling, from Eric
      Dumazet and Willem de Bruijn.

  14) Support TLS offload in nfp driver, from Jakub Kicinski, Dirk van
      der Merwe, and others.

  15) Various improvements to axienet driver including converting it to
      phylink, from Robert Hancock.

  16) Add PTP support to sja1105 DSA driver, from Vladimir Oltean.

  17) Add mqprio qdisc offload support to dpaa2-eth, from Ioana
      Radulescu.

  18) Add devlink health reporting to mlx5, from Moshe Shemesh.

  19) Convert stmmac over to phylink, from Jose Abreu.

  20) Add PTP PHC (Physical Hardware Clock) support to mlxsw, from
      Shalom Toledo.

  21) Add nftables SYNPROXY support, from Fernando Fernandez Mancera.

  22) Convert tcp_fastopen over to use SipHash, from Ard Biesheuvel.

  23) Track spill/fill of constants in BPF verifier, from Alexei
      Starovoitov.

  24) Support bounded loops in BPF, from Alexei Starovoitov.

  25) Various page_pool API fixes and improvements, from Jesper Dangaard
      Brouer.

  26) Just like ipv4, support ref-countless ipv6 route handling. From
      Wei Wang.

  27) Support VLAN offloading in aquantia driver, from Igor Russkikh.

  28) Add AF_XDP zero-copy support to mlx5, from Maxim Mikityanskiy.

  29) Add flower GRE encap/decap support to nfp driver, from Pieter
      Jansen van Vuuren.

  30) Protect against stack overflow when using act_mirred, from John
      Hurley.

  31) Allow devmap map lookups from eBPF, from Toke Høiland-Jørgensen.

  32) Use page_pool API in netsec driver, Ilias Apalodimas.

  33) Add Google gve network driver, from Catherine Sullivan.

  34) More indirect call avoidance, from Paolo Abeni.

  35) Add kTLS TX HW offload support to mlx5, from Tariq Toukan.

  36) Add XDP_REDIRECT support to bnxt_en, from Andy Gospodarek.

  37) Add MPLS manipulation actions to TC, from John Hurley.

  38) Add sending a packet to connection tracking from TC actions, and
      then allow flower classifier matching on conntrack state. From
      Paul Blakey.

  39) Netfilter hw offload support, from Pablo Neira Ayuso"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2080 commits)
  net/mlx5e: Return in default case statement in tx_post_resync_params
  mlx5: Return -EINVAL when WARN_ON_ONCE triggers in mlx5e_tls_resync().
  net: dsa: add support for BRIDGE_MROUTER attribute
  pkt_sched: Include const.h
  net: netsec: remove static declaration for netsec_set_tx_de()
  net: netsec: remove superfluous if statement
  netfilter: nf_tables: add hardware offload support
  net: flow_offload: rename tc_cls_flower_offload to flow_cls_offload
  net: flow_offload: add flow_block_cb_is_busy() and use it
  net: sched: remove tcf block API
  drivers: net: use flow block API
  net: sched: use flow block API
  net: flow_offload: add flow_block_cb_{priv, incref, decref}()
  net: flow_offload: add list handling functions
  net: flow_offload: add flow_block_cb_alloc() and flow_block_cb_free()
  net: flow_offload: rename TCF_BLOCK_BINDER_TYPE_* to FLOW_BLOCK_BINDER_TYPE_*
  net: flow_offload: rename TC_BLOCK_{UN}BIND to FLOW_BLOCK_{UN}BIND
  net: flow_offload: add flow_block_cb_setup_simple()
  net: hisilicon: Add an tx_desc to adapt HI13X1_GMAC
  net: hisilicon: Add an rx_desc to adapt HI13X1_GMAC
  ...

1 files changed, 1006 insertions, 0 deletions

diff --git a/drivers/staging/isdn/gigaset/isocdata.c b/drivers/staging/isdn/gigaset/isocdata.c
new file mode 100644
index 000000000000..3ecf6e33ed15
--- /dev/null
+++ b/drivers/staging/isdn/gigaset/isocdata.c
@@ -0,0 +1,1006 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Common data handling layer for bas_gigaset
+ *
+ * Copyright (c) 2005 by Tilman Schmidt <tilman@imap.cc>,
+ *                       Hansjoerg Lipp <hjlipp@web.de>.
+ *
+ * =====================================================================
+ * =====================================================================
+ */
+
+#include "gigaset.h"
+#include <linux/crc-ccitt.h>
+#include <linux/bitrev.h>
+
+/* access methods for isowbuf_t */
+/* ============================ */
+
+/* initialize buffer structure
+ */
+void gigaset_isowbuf_init(struct isowbuf_t *iwb, unsigned char idle)
+{
+	iwb->read = 0;
+	iwb->nextread = 0;
+	iwb->write = 0;
+	atomic_set(&iwb->writesem, 1);
+	iwb->wbits = 0;
+	iwb->idle = idle;
+	memset(iwb->data + BAS_OUTBUFSIZE, idle, BAS_OUTBUFPAD);
+}
+
+/* compute number of bytes which can be appended to buffer
+ * so that there is still room to append a maximum frame of flags
+ */
+static inline int isowbuf_freebytes(struct isowbuf_t *iwb)
+{
+	int read, write, freebytes;
+
+	read = iwb->read;
+	write = iwb->write;
+	freebytes = read - write;
+	if (freebytes > 0) {
+		/* no wraparound: need padding space within regular area */
+		return freebytes - BAS_OUTBUFPAD;
+	} else if (read < BAS_OUTBUFPAD) {
+		/* wraparound: can use space up to end of regular area */
+		return BAS_OUTBUFSIZE - write;
+	} else {
+		/* following the wraparound yields more space */
+		return freebytes + BAS_OUTBUFSIZE - BAS_OUTBUFPAD;
+	}
+}
+
+/* start writing
+ * acquire the write semaphore
+ * return 0 if acquired, <0 if busy
+ */
+static inline int isowbuf_startwrite(struct isowbuf_t *iwb)
+{
+	if (!atomic_dec_and_test(&iwb->writesem)) {
+		atomic_inc(&iwb->writesem);
+		gig_dbg(DEBUG_ISO, "%s: couldn't acquire iso write semaphore",
+			__func__);
+		return -EBUSY;
+	}
+	gig_dbg(DEBUG_ISO,
+		"%s: acquired iso write semaphore, data[write]=%02x, nbits=%d",
+		__func__, iwb->data[iwb->write], iwb->wbits);
+	return 0;
+}
+
+/* finish writing
+ * release the write semaphore
+ * returns the current write position
+ */
+static inline int isowbuf_donewrite(struct isowbuf_t *iwb)
+{
+	int write = iwb->write;
+	atomic_inc(&iwb->writesem);
+	return write;
+}
+
+/* append bits to buffer without any checks
+ * - data contains bits to append, starting at LSB
+ * - nbits is number of bits to append (0..24)
+ * must be called with the write semaphore held
+ * If more than nbits bits are set in data, the extraneous bits are set in the
+ * buffer too, but the write position is only advanced by nbits.
+ */
+static inline void isowbuf_putbits(struct isowbuf_t *iwb, u32 data, int nbits)
+{
+	int write = iwb->write;
+	data <<= iwb->wbits;
+	data |= iwb->data[write];
+	nbits += iwb->wbits;
+	while (nbits >= 8) {
+		iwb->data[write++] = data & 0xff;
+		write %= BAS_OUTBUFSIZE;
+		data >>= 8;
+		nbits -= 8;
+	}
+	iwb->wbits = nbits;
+	iwb->data[write] = data & 0xff;
+	iwb->write = write;
+}
+
+/* put final flag on HDLC bitstream
+ * also sets the idle fill byte to the correspondingly shifted flag pattern
+ * must be called with the write semaphore held
+ */
+static inline void isowbuf_putflag(struct isowbuf_t *iwb)
+{
+	int write;
+
+	/* add two flags, thus reliably covering one byte */
+	isowbuf_putbits(iwb, 0x7e7e, 8);
+	/* recover the idle flag byte */
+	write = iwb->write;
+	iwb->idle = iwb->data[write];
+	gig_dbg(DEBUG_ISO, "idle fill byte %02x", iwb->idle);
+	/* mask extraneous bits in buffer */
+	iwb->data[write] &= (1 << iwb->wbits) - 1;
+}
+
+/* retrieve a block of bytes for sending
+ * The requested number of bytes is provided as a contiguous block.
+ * If necessary, the frame is filled to the requested number of bytes
+ * with the idle value.
+ * returns offset to frame, < 0 on busy or error
+ */
+int gigaset_isowbuf_getbytes(struct isowbuf_t *iwb, int size)
+{
+	int read, write, limit, src, dst;
+	unsigned char pbyte;
+
+	read = iwb->nextread;
+	write = iwb->write;
+	if (likely(read == write)) {
+		/* return idle frame */
+		return read < BAS_OUTBUFPAD ?
+			BAS_OUTBUFSIZE : read - BAS_OUTBUFPAD;
+	}
+
+	limit = read + size;
+	gig_dbg(DEBUG_STREAM, "%s: read=%d write=%d limit=%d",
+		__func__, read, write, limit);
+#ifdef CONFIG_GIGASET_DEBUG
+	if (unlikely(size < 0 || size > BAS_OUTBUFPAD)) {
+		pr_err("invalid size %d\n", size);
+		return -EINVAL;
+	}
+#endif
+
+	if (read < write) {
+		/* no wraparound in valid data */
+		if (limit >= write) {
+			/* append idle frame */
+			if (isowbuf_startwrite(iwb) < 0)
+				return -EBUSY;
+			/* write position could have changed */
+			write = iwb->write;
+			if (limit >= write) {
+				pbyte = iwb->data[write]; /* save
+							     partial byte */
+				limit = write + BAS_OUTBUFPAD;
+				gig_dbg(DEBUG_STREAM,
+					"%s: filling %d->%d with %02x",
+					__func__, write, limit, iwb->idle);
+				if (write + BAS_OUTBUFPAD < BAS_OUTBUFSIZE)
+					memset(iwb->data + write, iwb->idle,
+					       BAS_OUTBUFPAD);
+				else {
+					/* wraparound, fill entire pad area */
+					memset(iwb->data + write, iwb->idle,
+					       BAS_OUTBUFSIZE + BAS_OUTBUFPAD
+					       - write);
+					limit = 0;
+				}
+				gig_dbg(DEBUG_STREAM,
+					"%s: restoring %02x at %d",
+					__func__, pbyte, limit);
+				iwb->data[limit] = pbyte; /* restore
+							     partial byte */
+				iwb->write = limit;
+			}
+			isowbuf_donewrite(iwb);
+		}
+	} else {
+		/* valid data wraparound */
+		if (limit >= BAS_OUTBUFSIZE) {
+			/* copy wrapped part into pad area */
+			src = 0;
+			dst = BAS_OUTBUFSIZE;
+			while (dst < limit && src < write)
+				iwb->data[dst++] = iwb->data[src++];
+			if (dst <= limit) {
+				/* fill pad area with idle byte */
+				memset(iwb->data + dst, iwb->idle,
+				       BAS_OUTBUFSIZE + BAS_OUTBUFPAD - dst);
+			}
+			limit = src;
+		}
+	}
+	iwb->nextread = limit;
+	return read;
+}
+
+/* dump_bytes
+ * write hex bytes to syslog for debugging
+ */
+static inline void dump_bytes(enum debuglevel level, const char *tag,
+			      unsigned char *bytes, int count)
+{
+#ifdef CONFIG_GIGASET_DEBUG
+	unsigned char c;
+	static char dbgline[3 * 32 + 1];
+	int i = 0;
+
+	if (!(gigaset_debuglevel & level))
+		return;
+
+	while (count-- > 0) {
+		if (i > sizeof(dbgline) - 4) {
+			dbgline[i] = '\0';
+			gig_dbg(level, "%s:%s", tag, dbgline);
+			i = 0;
+		}
+		c = *bytes++;
+		dbgline[i] = (i && !(i % 12)) ? '-' : ' ';
+		i++;
+		dbgline[i++] = hex_asc_hi(c);
+		dbgline[i++] = hex_asc_lo(c);
+	}
+	dbgline[i] = '\0';
+	gig_dbg(level, "%s:%s", tag, dbgline);
+#endif
+}
+
+/*============================================================================*/
+
+/* bytewise HDLC bitstuffing via table lookup
+ * lookup table: 5 subtables for 0..4 preceding consecutive '1' bits
+ * index: 256*(number of preceding '1' bits) + (next byte to stuff)
+ * value: bit  9.. 0 = result bits
+ *        bit 12..10 = number of trailing '1' bits in result
+ *        bit 14..13 = number of bits added by stuffing
+ */
+static const u16 stufftab[5 * 256] = {
+/* previous 1s = 0: */
+	0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
+	0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x201f,
+	0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
+	0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x205f,
+	0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
+	0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x209f,
+	0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
+	0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20df,
+	0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x0487, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x048f,
+	0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x0497, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x251f,
+	0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x04a7, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x04af,
+	0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x04b7, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x255f,
+	0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x08c7, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x08cf,
+	0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x08d7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x299f,
+	0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x0ce7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x0cef,
+	0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x10f7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x2ddf,
+
+/* previous 1s = 1: */
+	0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x200f,
+	0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x202f,
+	0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x204f,
+	0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x206f,
+	0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x208f,
+	0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x20af,
+	0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x20cf,
+	0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20ef,
+	0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x0487, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x250f,
+	0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x0497, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x252f,
+	0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x04a7, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x254f,
+	0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x04b7, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x256f,
+	0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x08c7, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x298f,
+	0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x08d7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x29af,
+	0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x0ce7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x2dcf,
+	0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x10f7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x31ef,
+
+/* previous 1s = 2: */
+	0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x2007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x2017,
+	0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x2027, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x2037,
+	0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x2047, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x2057,
+	0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x2067, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x2077,
+	0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x2087, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x2097,
+	0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x20a7, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x20b7,
+	0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x20c7, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x20d7,
+	0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x20e7, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20f7,
+	0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x2507, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x2517,
+	0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x2527, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x2537,
+	0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x2547, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x2557,
+	0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x2567, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x2577,
+	0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x2987, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x2997,
+	0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x29a7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x29b7,
+	0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x2dc7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x2dd7,
+	0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x31e7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x41f7,
+
+/* previous 1s = 3: */
+	0x0000, 0x0001, 0x0002, 0x2003, 0x0004, 0x0005, 0x0006, 0x200b, 0x0008, 0x0009, 0x000a, 0x2013, 0x000c, 0x000d, 0x000e, 0x201b,
+	0x0010, 0x0011, 0x0012, 0x2023, 0x0014, 0x0015, 0x0016, 0x202b, 0x0018, 0x0019, 0x001a, 0x2033, 0x001c, 0x001d, 0x001e, 0x203b,
+	0x0020, 0x0021, 0x0022, 0x2043, 0x0024, 0x0025, 0x0026, 0x204b, 0x0028, 0x0029, 0x002a, 0x2053, 0x002c, 0x002d, 0x002e, 0x205b,
+	0x0030, 0x0031, 0x0032, 0x2063, 0x0034, 0x0035, 0x0036, 0x206b, 0x0038, 0x0039, 0x003a, 0x2073, 0x003c, 0x003d, 0x203e, 0x207b,
+	0x0040, 0x0041, 0x0042, 0x2083, 0x0044, 0x0045, 0x0046, 0x208b, 0x0048, 0x0049, 0x004a, 0x2093, 0x004c, 0x004d, 0x004e, 0x209b,
+	0x0050, 0x0051, 0x0052, 0x20a3, 0x0054, 0x0055, 0x0056, 0x20ab, 0x0058, 0x0059, 0x005a, 0x20b3, 0x005c, 0x005d, 0x005e, 0x20bb,
+	0x0060, 0x0061, 0x0062, 0x20c3, 0x0064, 0x0065, 0x0066, 0x20cb, 0x0068, 0x0069, 0x006a, 0x20d3, 0x006c, 0x006d, 0x006e, 0x20db,
+	0x0070, 0x0071, 0x0072, 0x20e3, 0x0074, 0x0075, 0x0076, 0x20eb, 0x0078, 0x0079, 0x007a, 0x20f3, 0x207c, 0x207d, 0x20be, 0x40fb,
+	0x0480, 0x0481, 0x0482, 0x2503, 0x0484, 0x0485, 0x0486, 0x250b, 0x0488, 0x0489, 0x048a, 0x2513, 0x048c, 0x048d, 0x048e, 0x251b,
+	0x0490, 0x0491, 0x0492, 0x2523, 0x0494, 0x0495, 0x0496, 0x252b, 0x0498, 0x0499, 0x049a, 0x2533, 0x049c, 0x049d, 0x049e, 0x253b,
+	0x04a0, 0x04a1, 0x04a2, 0x2543, 0x04a4, 0x04a5, 0x04a6, 0x254b, 0x04a8, 0x04a9, 0x04aa, 0x2553, 0x04ac, 0x04ad, 0x04ae, 0x255b,
+	0x04b0, 0x04b1, 0x04b2, 0x2563, 0x04b4, 0x04b5, 0x04b6, 0x256b, 0x04b8, 0x04b9, 0x04ba, 0x2573, 0x04bc, 0x04bd, 0x253e, 0x257b,
+	0x08c0, 0x08c1, 0x08c2, 0x2983, 0x08c4, 0x08c5, 0x08c6, 0x298b, 0x08c8, 0x08c9, 0x08ca, 0x2993, 0x08cc, 0x08cd, 0x08ce, 0x299b,
+	0x08d0, 0x08d1, 0x08d2, 0x29a3, 0x08d4, 0x08d5, 0x08d6, 0x29ab, 0x08d8, 0x08d9, 0x08da, 0x29b3, 0x08dc, 0x08dd, 0x08de, 0x29bb,
+	0x0ce0, 0x0ce1, 0x0ce2, 0x2dc3, 0x0ce4, 0x0ce5, 0x0ce6, 0x2dcb, 0x0ce8, 0x0ce9, 0x0cea, 0x2dd3, 0x0cec, 0x0ced, 0x0cee, 0x2ddb,
+	0x10f0, 0x10f1, 0x10f2, 0x31e3, 0x10f4, 0x10f5, 0x10f6, 0x31eb, 0x20f8, 0x20f9, 0x20fa, 0x41f3, 0x257c, 0x257d, 0x29be, 0x46fb,
+
+/* previous 1s = 4: */
+	0x0000, 0x2001, 0x0002, 0x2005, 0x0004, 0x2009, 0x0006, 0x200d, 0x0008, 0x2011, 0x000a, 0x2015, 0x000c, 0x2019, 0x000e, 0x201d,
+	0x0010, 0x2021, 0x0012, 0x2025, 0x0014, 0x2029, 0x0016, 0x202d, 0x0018, 0x2031, 0x001a, 0x2035, 0x001c, 0x2039, 0x001e, 0x203d,
+	0x0020, 0x2041, 0x0022, 0x2045, 0x0024, 0x2049, 0x0026, 0x204d, 0x0028, 0x2051, 0x002a, 0x2055, 0x002c, 0x2059, 0x002e, 0x205d,
+	0x0030, 0x2061, 0x0032, 0x2065, 0x0034, 0x2069, 0x0036, 0x206d, 0x0038, 0x2071, 0x003a, 0x2075, 0x003c, 0x2079, 0x203e, 0x407d,
+	0x0040, 0x2081, 0x0042, 0x2085, 0x0044, 0x2089, 0x0046, 0x208d, 0x0048, 0x2091, 0x004a, 0x2095, 0x004c, 0x2099, 0x004e, 0x209d,
+	0x0050, 0x20a1, 0x0052, 0x20a5, 0x0054, 0x20a9, 0x0056, 0x20ad, 0x0058, 0x20b1, 0x005a, 0x20b5, 0x005c, 0x20b9, 0x005e, 0x20bd,
+	0x0060, 0x20c1, 0x0062, 0x20c5, 0x0064, 0x20c9, 0x0066, 0x20cd, 0x0068, 0x20d1, 0x006a, 0x20d5, 0x006c, 0x20d9, 0x006e, 0x20dd,
+	0x0070, 0x20e1, 0x0072, 0x20e5, 0x0074, 0x20e9, 0x0076, 0x20ed, 0x0078, 0x20f1, 0x007a, 0x20f5, 0x207c, 0x40f9, 0x20be, 0x417d,
+	0x0480, 0x2501, 0x0482, 0x2505, 0x0484, 0x2509, 0x0486, 0x250d, 0x0488, 0x2511, 0x048a, 0x2515, 0x048c, 0x2519, 0x048e, 0x251d,
+	0x0490, 0x2521, 0x0492, 0x2525, 0x0494, 0x2529, 0x0496, 0x252d, 0x0498, 0x2531, 0x049a, 0x2535, 0x049c, 0x2539, 0x049e, 0x253d,
+	0x04a0, 0x2541, 0x04a2, 0x2545, 0x04a4, 0x2549, 0x04a6, 0x254d, 0x04a8, 0x2551, 0x04aa, 0x2555, 0x04ac, 0x2559, 0x04ae, 0x255d,
+	0x04b0, 0x2561, 0x04b2, 0x2565, 0x04b4, 0x2569, 0x04b6, 0x256d, 0x04b8, 0x2571, 0x04ba, 0x2575, 0x04bc, 0x2579, 0x253e, 0x467d,
+	0x08c0, 0x2981, 0x08c2, 0x2985, 0x08c4, 0x2989, 0x08c6, 0x298d, 0x08c8, 0x2991, 0x08ca, 0x2995, 0x08cc, 0x2999, 0x08ce, 0x299d,
+	0x08d0, 0x29a1, 0x08d2, 0x29a5, 0x08d4, 0x29a9, 0x08d6, 0x29ad, 0x08d8, 0x29b1, 0x08da, 0x29b5, 0x08dc, 0x29b9, 0x08de, 0x29bd,
+	0x0ce0, 0x2dc1, 0x0ce2, 0x2dc5, 0x0ce4, 0x2dc9, 0x0ce6, 0x2dcd, 0x0ce8, 0x2dd1, 0x0cea, 0x2dd5, 0x0cec, 0x2dd9, 0x0cee, 0x2ddd,
+	0x10f0, 0x31e1, 0x10f2, 0x31e5, 0x10f4, 0x31e9, 0x10f6, 0x31ed, 0x20f8, 0x41f1, 0x20fa, 0x41f5, 0x257c, 0x46f9, 0x29be, 0x4b7d
+};
+
+/* hdlc_bitstuff_byte
+ * perform HDLC bitstuffing for one input byte (8 bits, LSB first)
+ * parameters:
+ *	cin	input byte
+ *	ones	number of trailing '1' bits in result before this step
+ *	iwb	pointer to output buffer structure
+ *		(write semaphore must be held)
+ * return value:
+ *	number of trailing '1' bits in result after this step
+ */
+
+static inline int hdlc_bitstuff_byte(struct isowbuf_t *iwb, unsigned char cin,
+				     int ones)
+{
+	u16 stuff;
+	int shiftinc, newones;
+
+	/* get stuffing information for input byte
+	 * value: bit  9.. 0 = result bits
+	 *        bit 12..10 = number of trailing '1' bits in result
+	 *        bit 14..13 = number of bits added by stuffing
+	 */
+	stuff = stufftab[256 * ones + cin];
+	shiftinc = (stuff >> 13) & 3;
+	newones = (stuff >> 10) & 7;
+	stuff &= 0x3ff;
+
+	/* append stuffed byte to output stream */
+	isowbuf_putbits(iwb, stuff, 8 + shiftinc);
+	return newones;
+}
+
+/* hdlc_buildframe
+ * Perform HDLC framing with bitstuffing on a byte buffer
+ * The input buffer is regarded as a sequence of bits, starting with the least
+ * significant bit of the first byte and ending with the most significant bit
+ * of the last byte. A 16 bit FCS is appended as defined by RFC 1662.
+ * Whenever five consecutive '1' bits appear in the resulting bit sequence, a
+ * '0' bit is inserted after them.
+ * The resulting bit string and a closing flag pattern (PPP_FLAG, '01111110')
+ * are appended to the output buffer starting at the given bit position, which
+ * is assumed to already contain a leading flag.
+ * The output buffer must have sufficient length; count + count/5 + 6 bytes
+ * starting at *out are safe and are verified to be present.
+ * parameters:
+ *	in	input buffer
+ *	count	number of bytes in input buffer
+ *	iwb	pointer to output buffer structure
+ *		(write semaphore must be held)
+ * return value:
+ *	position of end of packet in output buffer on success,
+ *	-EAGAIN if write semaphore busy or buffer full
+ */
+
+static inline int hdlc_buildframe(struct isowbuf_t *iwb,
+				  unsigned char *in, int count)
+{
+	int ones;
+	u16 fcs;
+	int end;
+	unsigned char c;
+
+	if (isowbuf_freebytes(iwb) < count + count / 5 + 6 ||
+	    isowbuf_startwrite(iwb) < 0) {
+		gig_dbg(DEBUG_ISO, "%s: %d bytes free -> -EAGAIN",
+			__func__, isowbuf_freebytes(iwb));
+		return -EAGAIN;
+	}
+
+	dump_bytes(DEBUG_STREAM_DUMP, "snd data", in, count);
+
+	/* bitstuff and checksum input data */
+	fcs = PPP_INITFCS;
+	ones = 0;
+	while (count-- > 0) {
+		c = *in++;
+		ones = hdlc_bitstuff_byte(iwb, c, ones);
+		fcs = crc_ccitt_byte(fcs, c);
+	}
+
+	/* bitstuff and append FCS
+	 * (complemented, least significant byte first) */
+	fcs ^= 0xffff;
+	ones = hdlc_bitstuff_byte(iwb, fcs & 0x00ff, ones);
+	ones = hdlc_bitstuff_byte(iwb, (fcs >> 8) & 0x00ff, ones);
+
+	/* put closing flag and repeat byte for flag idle */
+	isowbuf_putflag(iwb);
+	end = isowbuf_donewrite(iwb);
+	return end;
+}
+
+/* trans_buildframe
+ * Append a block of 'transparent' data to the output buffer,
+ * inverting the bytes.
+ * The output buffer must have sufficient length; count bytes
+ * starting at *out are safe and are verified to be present.
+ * parameters:
+ *	in	input buffer
+ *	count	number of bytes in input buffer
+ *	iwb	pointer to output buffer structure
+ *		(write semaphore must be held)
+ * return value:
+ *	position of end of packet in output buffer on success,
+ *	-EAGAIN if write semaphore busy or buffer full
+ */
+
+static inline int trans_buildframe(struct isowbuf_t *iwb,
+				   unsigned char *in, int count)
+{
+	int write;
+	unsigned char c;
+
+	if (unlikely(count <= 0))
+		return iwb->write;
+
+	if (isowbuf_freebytes(iwb) < count ||
+	    isowbuf_startwrite(iwb) < 0) {
+		gig_dbg(DEBUG_ISO, "can't put %d bytes", count);
+		return -EAGAIN;
+	}
+
+	gig_dbg(DEBUG_STREAM, "put %d bytes", count);
+	dump_bytes(DEBUG_STREAM_DUMP, "snd data", in, count);
+
+	write = iwb->write;
+	do {
+		c = bitrev8(*in++);
+		iwb->data[write++] = c;
+		write %= BAS_OUTBUFSIZE;
+	} while (--count > 0);
+	iwb->write = write;
+	iwb->idle = c;
+
+	return isowbuf_donewrite(iwb);
+}
+
+int gigaset_isoc_buildframe(struct bc_state *bcs, unsigned char *in, int len)
+{
+	int result;
+
+	switch (bcs->proto2) {
+	case L2_HDLC:
+		result = hdlc_buildframe(bcs->hw.bas->isooutbuf, in, len);
+		gig_dbg(DEBUG_ISO, "%s: %d bytes HDLC -> %d",
+			__func__, len, result);
+		break;
+	default:			/* assume transparent */
+		result = trans_buildframe(bcs->hw.bas->isooutbuf, in, len);
+		gig_dbg(DEBUG_ISO, "%s: %d bytes trans -> %d",
+			__func__, len, result);
+	}
+	return result;
+}
+
+/* hdlc_putbyte
+ * append byte c to current skb of B channel structure *bcs, updating fcs
+ */
+static inline void hdlc_putbyte(unsigned char c, struct bc_state *bcs)
+{
+	bcs->rx_fcs = crc_ccitt_byte(bcs->rx_fcs, c);
+	if (bcs->rx_skb == NULL)
+		/* skipping */
+		return;
+	if (bcs->rx_skb->len >= bcs->rx_bufsize) {
+		dev_warn(bcs->cs->dev, "received oversized packet discarded\n");
+		bcs->hw.bas->giants++;
+		dev_kfree_skb_any(bcs->rx_skb);
+		bcs->rx_skb = NULL;
+		return;
+	}
+	__skb_put_u8(bcs->rx_skb, c);
+}
+
+/* hdlc_flush
+ * drop partial HDLC data packet
+ */
+static inline void hdlc_flush(struct bc_state *bcs)
+{
+	/* clear skb or allocate new if not skipping */
+	if (bcs->rx_skb != NULL)
+		skb_trim(bcs->rx_skb, 0);
+	else
+		gigaset_new_rx_skb(bcs);
+
+	/* reset packet state */
+	bcs->rx_fcs = PPP_INITFCS;
+}
+
+/* hdlc_done
+ * process completed HDLC data packet
+ */
+static inline void hdlc_done(struct bc_state *bcs)
+{
+	struct cardstate *cs = bcs->cs;
+	struct sk_buff *procskb;
+	unsigned int len;
+
+	if (unlikely(bcs->ignore)) {
+		bcs->ignore--;
+		hdlc_flush(bcs);
+		return;
+	}
+	procskb = bcs->rx_skb;
+	if (procskb == NULL) {
+		/* previous error */
+		gig_dbg(DEBUG_ISO, "%s: skb=NULL", __func__);
+		gigaset_isdn_rcv_err(bcs);
+	} else if (procskb->len < 2) {
+		dev_notice(cs->dev, "received short frame (%d octets)\n",
+			   procskb->len);
+		bcs->hw.bas->runts++;
+		dev_kfree_skb_any(procskb);
+		gigaset_isdn_rcv_err(bcs);
+	} else if (bcs->rx_fcs != PPP_GOODFCS) {
+		dev_notice(cs->dev, "frame check error\n");
+		bcs->hw.bas->fcserrs++;
+		dev_kfree_skb_any(procskb);
+		gigaset_isdn_rcv_err(bcs);
+	} else {
+		len = procskb->len;
+		__skb_trim(procskb, len -= 2);	/* subtract FCS */
+		gig_dbg(DEBUG_ISO, "%s: good frame (%d octets)", __func__, len);
+		dump_bytes(DEBUG_STREAM_DUMP,
+			   "rcv data", procskb->data, len);
+		bcs->hw.bas->goodbytes += len;
+		gigaset_skb_rcvd(bcs, procskb);
+	}
+	gigaset_new_rx_skb(bcs);
+	bcs->rx_fcs = PPP_INITFCS;
+}
+
+/* hdlc_frag
+ * drop HDLC data packet with non-integral last byte
+ */
+static inline void hdlc_frag(struct bc_state *bcs, unsigned inbits)
+{
+	if (unlikely(bcs->ignore)) {
+		bcs->ignore--;
+		hdlc_flush(bcs);
+		return;
+	}
+
+	dev_notice(bcs->cs->dev, "received partial byte (%d bits)\n", inbits);
+	bcs->hw.bas->alignerrs++;
+	gigaset_isdn_rcv_err(bcs);
+	__skb_trim(bcs->rx_skb, 0);
+	bcs->rx_fcs = PPP_INITFCS;
+}
+
+/* bit counts lookup table for HDLC bit unstuffing
+ * index: input byte
+ * value: bit 0..3 = number of consecutive '1' bits starting from LSB
+ *        bit 4..6 = number of consecutive '1' bits starting from MSB
+ *		     (replacing 8 by 7 to make it fit; the algorithm won't care)
+ *        bit 7 set if there are 5 or more "interior" consecutive '1' bits
+ */
+static const unsigned char bitcounts[256] = {
+	0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
+	0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x05,
+	0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
+	0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x80, 0x06,
+	0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
+	0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x05,
+	0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
+	0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x80, 0x81, 0x80, 0x07,
+	0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x14,
+	0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x15,
+	0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x14,
+	0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x90, 0x16,
+	0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x23, 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x24,
+	0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x23, 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x25,
+	0x30, 0x31, 0x30, 0x32, 0x30, 0x31, 0x30, 0x33, 0x30, 0x31, 0x30, 0x32, 0x30, 0x31, 0x30, 0x34,
+	0x40, 0x41, 0x40, 0x42, 0x40, 0x41, 0x40, 0x43, 0x50, 0x51, 0x50, 0x52, 0x60, 0x61, 0x70, 0x78
+};
+
+/* hdlc_unpack
+ * perform HDLC frame processing (bit unstuffing, flag detection, FCS
+ * calculation) on a sequence of received data bytes (8 bits each, LSB first)
+ * pass on successfully received, complete frames as SKBs via gigaset_skb_rcvd
+ * notify of errors via gigaset_isdn_rcv_err
+ * tally frames, errors etc. in BC structure counters
+ * parameters:
+ *	src	received data
+ *	count	number of received bytes
+ *	bcs	receiving B channel structure
+ */
+static inline void hdlc_unpack(unsigned char *src, unsigned count,
+			       struct bc_state *bcs)
+{
+	struct bas_bc_state *ubc = bcs->hw.bas;
+	int inputstate;
+	unsigned seqlen, inbyte, inbits;
+
+	/* load previous state:
+	 * inputstate = set of flag bits:
+	 * - INS_flag_hunt: no complete opening flag received since connection
+	 *                  setup or last abort
+	 * - INS_have_data: at least one complete data byte received since last
+	 *                  flag
+	 * seqlen = number of consecutive '1' bits in last 7 input stream bits
+	 *          (0..7)
+	 * inbyte = accumulated partial data byte (if !INS_flag_hunt)
+	 * inbits = number of valid bits in inbyte, starting at LSB (0..6)
+	 */
+	inputstate = bcs->inputstate;
+	seqlen = ubc->seqlen;
+	inbyte = ubc->inbyte;
+	inbits = ubc->inbits;
+
+	/* bit unstuffing a byte a time
+	 * Take your time to understand this; it's straightforward but tedious.
+	 * The "bitcounts" lookup table is used to speed up the counting of
+	 * leading and trailing '1' bits.
+	 */
+	while (count--) {
+		unsigned char c = *src++;
+		unsigned char tabentry = bitcounts[c];
+		unsigned lead1 = tabentry & 0x0f;
+		unsigned trail1 = (tabentry >> 4) & 0x0f;
+
+		seqlen += lead1;
+
+		if (unlikely(inputstate & INS_flag_hunt)) {
+			if (c == PPP_FLAG) {
+				/* flag-in-one */
+				inputstate &= ~(INS_flag_hunt | INS_have_data);
+				inbyte = 0;
+				inbits = 0;
+			} else if (seqlen == 6 && trail1 != 7) {
+				/* flag completed & not followed by abort */
+				inputstate &= ~(INS_flag_hunt | INS_have_data);
+				inbyte = c >> (lead1 + 1);
+				inbits = 7 - lead1;
+				if (trail1 >= 8) {
+					/* interior stuffing:
+					 * omitting the MSB handles most cases,
+					 * correct the incorrectly handled
+					 * cases individually */
+					inbits--;
+					switch (c) {
+					case 0xbe:
+						inbyte = 0x3f;
+						break;
+					}
+				}
+			}
+			/* else: continue flag-hunting */
+		} else if (likely(seqlen < 5 && trail1 < 7)) {
+			/* streamlined case: 8 data bits, no stuffing */
+			inbyte |= c << inbits;
+			hdlc_putbyte(inbyte & 0xff, bcs);
+			inputstate |= INS_have_data;
+			inbyte >>= 8;
+			/* inbits unchanged */
+		} else if (likely(seqlen == 6 && inbits == 7 - lead1 &&
+				  trail1 + 1 == inbits &&
+				  !(inputstate & INS_have_data))) {
+			/* streamlined case: flag idle - state unchanged */
+		} else if (unlikely(seqlen > 6)) {
+			/* abort sequence */
+			ubc->aborts++;
+			hdlc_flush(bcs);
+			inputstate |= INS_flag_hunt;
+		} else if (seqlen == 6) {
+			/* closing flag, including (6 - lead1) '1's
+			 * and one '0' from inbits */
+			if (inbits > 7 - lead1) {
+				hdlc_frag(bcs, inbits + lead1 - 7);
+				inputstate &= ~INS_have_data;
+			} else {
+				if (inbits < 7 - lead1)
+					ubc->stolen0s++;
+				if (inputstate & INS_have_data) {
+					hdlc_done(bcs);
+					inputstate &= ~INS_have_data;
+				}
+			}
+
+			if (c == PPP_FLAG) {
+				/* complete flag, LSB overlaps preceding flag */
+				ubc->shared0s++;
+				inbits = 0;
+				inbyte = 0;
+			} else if (trail1 != 7) {
+				/* remaining bits */
+				inbyte = c >> (lead1 + 1);
+				inbits = 7 - lead1;
+				if (trail1 >= 8) {
+					/* interior stuffing:
+					 * omitting the MSB handles most cases,
+					 * correct the incorrectly handled
+					 * cases individually */
+					inbits--;
+					switch (c) {
+					case 0xbe:
+						inbyte = 0x3f;
+						break;
+					}
+				}
+			} else {
+				/* abort sequence follows,
+				 * skb already empty anyway */
+				ubc->aborts++;
+				inputstate |= INS_flag_hunt;
+			}
+		} else { /* (seqlen < 6) && (seqlen == 5 || trail1 >= 7) */
+
+			if (c == PPP_FLAG) {
+				/* complete flag */
+				if (seqlen == 5)
+					ubc->stolen0s++;
+				if (inbits) {
+					hdlc_frag(bcs, inbits);
+					inbits = 0;
+					inbyte = 0;
+				} else if (inputstate & INS_have_data)
+					hdlc_done(bcs);
+				inputstate &= ~INS_have_data;
+			} else if (trail1 == 7) {
+				/* abort sequence */
+				ubc->aborts++;
+				hdlc_flush(bcs);
+				inputstate |= INS_flag_hunt;
+			} else {
+				/* stuffed data */
+				if (trail1 < 7) { /* => seqlen == 5 */
+					/* stuff bit at position lead1,
+					 * no interior stuffing */
+					unsigned char mask = (1 << lead1) - 1;
+					c = (c & mask) | ((c & ~mask) >> 1);
+					inbyte |= c << inbits;
+					inbits += 7;
+				} else if (seqlen < 5) { /* trail1 >= 8 */
+					/* interior stuffing:
+					 * omitting the MSB handles most cases,
+					 * correct the incorrectly handled
+					 * cases individually */
+					switch (c) {
+					case 0xbe:
+						c = 0x7e;
+						break;
+					}
+					inbyte |= c << inbits;
+					inbits += 7;
+				} else { /* seqlen == 5 && trail1 >= 8 */
+
+					/* stuff bit at lead1 *and* interior
+					 * stuffing -- unstuff individually */
+					switch (c) {
+					case 0x7d:
+						c = 0x3f;
+						break;
+					case 0xbe:
+						c = 0x3f;
+						break;
+					case 0x3e:
+						c = 0x1f;
+						break;
+					case 0x7c:
+						c = 0x3e;
+						break;
+					}
+					inbyte |= c << inbits;
+					inbits += 6;
+				}
+				if (inbits >= 8) {
+					inbits -= 8;
+					hdlc_putbyte(inbyte & 0xff, bcs);
+					inputstate |= INS_have_data;
+					inbyte >>= 8;
+				}
+			}
+		}
+		seqlen = trail1 & 7;
+	}
+
+	/* save new state */
+	bcs->inputstate = inputstate;
+	ubc->seqlen = seqlen;
+	ubc->inbyte = inbyte;
+	ubc->inbits = inbits;
+}
+
+/* trans_receive
+ * pass on received USB frame transparently as SKB via gigaset_skb_rcvd
+ * invert bytes
+ * tally frames, errors etc. in BC structure counters
+ * parameters:
+ *	src	received data
+ *	count	number of received bytes
+ *	bcs	receiving B channel structure
+ */
+static inline void trans_receive(unsigned char *src, unsigned count,
+				 struct bc_state *bcs)
+{
+	struct sk_buff *skb;
+	int dobytes;
+	unsigned char *dst;
+
+	if (unlikely(bcs->ignore)) {
+		bcs->ignore--;
+		return;
+	}
+	skb = bcs->rx_skb;
+	if (skb == NULL) {
+		skb = gigaset_new_rx_skb(bcs);
+		if (skb == NULL)
+			return;
+	}
+	dobytes = bcs->rx_bufsize - skb->len;
+	while (count > 0) {
+		dst = skb_put(skb, count < dobytes ? count : dobytes);
+		while (count > 0 && dobytes > 0) {
+			*dst++ = bitrev8(*src++);
+			count--;
+			dobytes--;
+		}
+		if (dobytes == 0) {
+			dump_bytes(DEBUG_STREAM_DUMP,
+				   "rcv data", skb->data, skb->len);
+			bcs->hw.bas->goodbytes += skb->len;
+			gigaset_skb_rcvd(bcs, skb);
+			skb = gigaset_new_rx_skb(bcs);
+			if (skb == NULL)
+				return;
+			dobytes = bcs->rx_bufsize;
+		}
+	}
+}
+
+void gigaset_isoc_receive(unsigned char *src, unsigned count,
+			  struct bc_state *bcs)
+{
+	switch (bcs->proto2) {
+	case L2_HDLC:
+		hdlc_unpack(src, count, bcs);
+		break;
+	default:		/* assume transparent */
+		trans_receive(src, count, bcs);
+	}
+}
+
+/* == data input =========================================================== */
+
+/* process a block of received bytes in command mode (mstate != MS_LOCKED)
+ * Append received bytes to the command response buffer and forward them
+ * line by line to the response handler.
+ * Note: Received lines may be terminated by CR, LF, or CR LF, which will be
+ * removed before passing the line to the response handler.
+ */
+static void cmd_loop(unsigned char *src, int numbytes, struct inbuf_t *inbuf)
+{
+	struct cardstate *cs = inbuf->cs;
+	unsigned cbytes      = cs->cbytes;
+	unsigned char c;
+
+	while (numbytes--) {
+		c = *src++;
+		switch (c) {
+		case '\n':
+			if (cbytes == 0 && cs->respdata[0] == '\r') {
+				/* collapse LF with preceding CR */
+				cs->respdata[0] = 0;
+				break;
+			}
+			/* fall through */
+		case '\r':
+			/* end of message line, pass to response handler */
+			if (cbytes >= MAX_RESP_SIZE) {
+				dev_warn(cs->dev, "response too large (%d)\n",
+					 cbytes);
+				cbytes = MAX_RESP_SIZE;
+			}
+			cs->cbytes = cbytes;
+			gigaset_dbg_buffer(DEBUG_TRANSCMD, "received response",
+					   cbytes, cs->respdata);
+			gigaset_handle_modem_response(cs);
+			cbytes = 0;
+
+			/* store EOL byte for CRLF collapsing */
+			cs->respdata[0] = c;
+			break;
+		default:
+			/* append to line buffer if possible */
+			if (cbytes < MAX_RESP_SIZE)
+				cs->respdata[cbytes] = c;
+			cbytes++;
+		}
+	}
+
+	/* save state */
+	cs->cbytes = cbytes;
+}
+
+
+/* process a block of data received through the control channel
+ */
+void gigaset_isoc_input(struct inbuf_t *inbuf)
+{
+	struct cardstate *cs = inbuf->cs;
+	unsigned tail, head, numbytes;
+	unsigned char *src;
+
+	head = inbuf->head;
+	while (head != (tail = inbuf->tail)) {
+		gig_dbg(DEBUG_INTR, "buffer state: %u -> %u", head, tail);
+		if (head > tail)
+			tail = RBUFSIZE;
+		src = inbuf->data + head;
+		numbytes = tail - head;
+		gig_dbg(DEBUG_INTR, "processing %u bytes", numbytes);
+
+		if (cs->mstate == MS_LOCKED) {
+			gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response",
+					   numbytes, src);
+			gigaset_if_receive(inbuf->cs, src, numbytes);
+		} else {
+			cmd_loop(src, numbytes, inbuf);
+		}
+
+		head += numbytes;
+		if (head == RBUFSIZE)
+			head = 0;
+		gig_dbg(DEBUG_INTR, "setting head to %u", head);
+		inbuf->head = head;
+	}
+}
+
+
+/* == data output ========================================================== */
+
+/**
+ * gigaset_isoc_send_skb() - queue an skb for sending
+ * @bcs:	B channel descriptor structure.
+ * @skb:	data to send.
+ *
+ * Called by LL to queue an skb for sending, and start transmission if
+ * necessary.
+ * Once the payload data has been transmitted completely, gigaset_skb_sent()
+ * will be called with the skb's link layer header preserved.
+ *
+ * Return value:
+ *	number of bytes accepted for sending (skb->len) if ok,
+ *	error code < 0 (eg. -ENODEV) on error
+ */
+int gigaset_isoc_send_skb(struct bc_state *bcs, struct sk_buff *skb)
+{
+	int len = skb->len;
+	unsigned long flags;
+
+	spin_lock_irqsave(&bcs->cs->lock, flags);
+	if (!bcs->cs->connected) {
+		spin_unlock_irqrestore(&bcs->cs->lock, flags);
+		return -ENODEV;
+	}
+
+	skb_queue_tail(&bcs->squeue, skb);
+	gig_dbg(DEBUG_ISO, "%s: skb queued, qlen=%d",
+		__func__, skb_queue_len(&bcs->squeue));
+
+	/* tasklet submits URB if necessary */
+	tasklet_schedule(&bcs->hw.bas->sent_tasklet);
+	spin_unlock_irqrestore(&bcs->cs->lock, flags);
+
+	return len;	/* ok so far */
+}