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linux/drivers/isdn/gigaset/isocdata.c
Tilman Schmidt 73a8881454 [PATCH] isdn4linux: Siemens Gigaset base driver: fix disconnect handling 
Fix a possible Oops in the Siemens Gigaset base driver when the device is
unplugged while an ISDN connection is still active, and makes sure that the
isdn4linux link level (LL) is properly informed if a connection is broken
by the USB cable being unplugged.

- Avoid unsafe checks of URB status fields outside the URB completion
  handlers, keep track of in-use URBs myself instead.

- If an isochronous transfer URB completes with status==0, also check the
  status of the frame descriptors.

- Verify length of interrupt messages received from the device.

- Align the length limit on transmitted AT commands with the device
  documentation.

- In case of AT response receive overrun, keep newly arrived instead of old
  unread data.

- Remove redundant check of device ID in the USB probe function.

- Correct and improve some comments and formatting.

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Acked-by: Hansjoerg Lipp <hjlipp@web.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-22 09:19:52 -07:00

1011 lines
36 KiB
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/*
* Common data handling layer for bas_gigaset
*
* Copyright (c) 2005 by Tilman Schmidt <tilman@imap.cc>,
* Hansjoerg Lipp <hjlipp@web.de>.
*
* =====================================================================
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
* =====================================================================
*/
#include "gigaset.h"
#include <linux/crc-ccitt.h>
/* access methods for isowbuf_t */
/* ============================ */
/* initialize buffer structure
*/
void gigaset_isowbuf_init(struct isowbuf_t *iwb, unsigned char idle)
{
atomic_set(&iwb->read, 0);
atomic_set(&iwb->nextread, 0);
atomic_set(&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 = atomic_read(&iwb->read);
write = atomic_read(&iwb->write);
if ((freebytes = read - write) > 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;
}
}
/* compare two offsets within the buffer
* The buffer is seen as circular, with the read position as start
* returns -1/0/1 if position a </=/> position b without crossing 'read'
*/
static inline int isowbuf_poscmp(struct isowbuf_t *iwb, int a, int b)
{
int read;
if (a == b)
return 0;
read = atomic_read(&iwb->read);
if (a < b) {
if (a < read && read <= b)
return +1;
else
return -1;
} else {
if (b < read && read <= a)
return -1;
else
return +1;
}
}
/* start writing
* acquire the write semaphore
* return true if acquired, false 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 0;
}
#ifdef CONFIG_GIGASET_DEBUG
gig_dbg(DEBUG_ISO,
"%s: acquired iso write semaphore, data[write]=%02x, nbits=%d",
__func__, iwb->data[atomic_read(&iwb->write)], iwb->wbits);
#endif
return 1;
}
/* finish writing
* release the write semaphore and update the maximum buffer fill level
* returns the current write position
*/
static inline int isowbuf_donewrite(struct isowbuf_t *iwb)
{
int write = atomic_read(&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 = atomic_read(&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;
atomic_set(&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 = atomic_read(&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 = atomic_read(&iwb->nextread);
write = atomic_read(&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)) {
err("invalid size %d", size);
return -EINVAL;
}
src = atomic_read(&iwb->read);
if (unlikely(limit > BAS_OUTBUFSIZE + BAS_OUTBUFPAD ||
(read < src && limit >= src))) {
err("isoc write buffer frame reservation violated");
return -EFAULT;
}
#endif
if (read < write) {
/* no wraparound in valid data */
if (limit >= write) {
/* append idle frame */
if (!isowbuf_startwrite(iwb))
return -EBUSY;
/* write position could have changed */
if (limit >= (write = atomic_read(&iwb->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 */
atomic_set(&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;
}
}
atomic_set(&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];
static const char hexdigit[] = "0123456789abcdef";
int i = 0;
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++] = hexdigit[(c >> 4) & 0x0f];
dbgline[i++] = hexdigit[c & 0x0f];
}
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 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)) {
gig_dbg(DEBUG_ISO, "%s: %d bytes free -> -EAGAIN",
__func__, isowbuf_freebytes(iwb));
return -EAGAIN;
}
dump_bytes(DEBUG_STREAM, "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);
dump_bytes(DEBUG_STREAM_DUMP, "isowbuf", iwb->data, end + 1);
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 atomic_read(&iwb->write); /* better ideas? */
if (isowbuf_freebytes(iwb) < count ||
!isowbuf_startwrite(iwb)) {
gig_dbg(DEBUG_ISO, "can't put %d bytes", count);
return -EAGAIN;
}
gig_dbg(DEBUG_STREAM, "put %d bytes", count);
write = atomic_read(&iwb->write);
do {
c = gigaset_invtab[*in++];
iwb->data[write++] = c;
write %= BAS_OUTBUFSIZE;
} while (--count > 0);
atomic_set(&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 ISDN_PROTO_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->fcs = crc_ccitt_byte(bcs->fcs, c);
if (unlikely(bcs->skb == NULL)) {
/* skipping */
return;
}
if (unlikely(bcs->skb->len == SBUFSIZE)) {
dev_warn(bcs->cs->dev, "received oversized packet discarded\n");
bcs->hw.bas->giants++;
dev_kfree_skb_any(bcs->skb);
bcs->skb = NULL;
return;
}
*__skb_put(bcs->skb, 1) = 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 (likely(bcs->skb != NULL))
skb_trim(bcs->skb, 0);
else if (!bcs->ignore) {
if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL)
skb_reserve(bcs->skb, HW_HDR_LEN);
else
dev_err(bcs->cs->dev, "could not allocate skb\n");
}
/* reset packet state */
bcs->fcs = PPP_INITFCS;
}
/* hdlc_done
* process completed HDLC data packet
*/
static inline void hdlc_done(struct bc_state *bcs)
{
struct sk_buff *procskb;
if (unlikely(bcs->ignore)) {
bcs->ignore--;
hdlc_flush(bcs);
return;
}
if ((procskb = bcs->skb) == NULL) {
/* previous error */
gig_dbg(DEBUG_ISO, "%s: skb=NULL", __func__);
gigaset_rcv_error(NULL, bcs->cs, bcs);
} else if (procskb->len < 2) {
dev_notice(bcs->cs->dev, "received short frame (%d octets)\n",
procskb->len);
bcs->hw.bas->runts++;
gigaset_rcv_error(procskb, bcs->cs, bcs);
} else if (bcs->fcs != PPP_GOODFCS) {
dev_notice(bcs->cs->dev, "frame check error (0x%04x)\n",
bcs->fcs);
bcs->hw.bas->fcserrs++;
gigaset_rcv_error(procskb, bcs->cs, bcs);
} else {
procskb->len -= 2; /* subtract FCS */
procskb->tail -= 2;
gig_dbg(DEBUG_ISO, "%s: good frame (%d octets)",
__func__, procskb->len);
dump_bytes(DEBUG_STREAM,
"rcv data", procskb->data, procskb->len);
bcs->hw.bas->goodbytes += procskb->len;
gigaset_rcv_skb(procskb, bcs->cs, bcs);
}
if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL)
skb_reserve(bcs->skb, HW_HDR_LEN);
else
dev_err(bcs->cs->dev, "could not allocate skb\n");
bcs->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_rcv_error(bcs->skb, bcs->cs, bcs);
if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL)
skb_reserve(bcs->skb, HW_HDR_LEN);
else
dev_err(bcs->cs->dev, "could not allocate skb\n");
bcs->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 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_rcv_skb
* notify of errors via gigaset_rcv_error
* 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 */
inbits--;
/* correct the incorrectly handled cases individually */
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 */
inbits--;
/* correct the incorrectly handled cases individually */
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 */
switch (c) { /* unstuff individually */
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_rcv_skb
* 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--;
hdlc_flush(bcs);
return;
}
if (unlikely((skb = bcs->skb) == NULL)) {
bcs->skb = skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN);
if (!skb) {
dev_err(bcs->cs->dev, "could not allocate skb\n");
return;
}
skb_reserve(skb, HW_HDR_LEN);
}
bcs->hw.bas->goodbytes += skb->len;
dobytes = TRANSBUFSIZE - skb->len;
while (count > 0) {
dst = skb_put(skb, count < dobytes ? count : dobytes);
while (count > 0 && dobytes > 0) {
*dst++ = gigaset_invtab[*src++];
count--;
dobytes--;
}
if (dobytes == 0) {
gigaset_rcv_skb(skb, bcs->cs, bcs);
bcs->skb = skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN);
if (!skb) {
dev_err(bcs->cs->dev,
"could not allocate skb\n");
return;
}
skb_reserve(bcs->skb, HW_HDR_LEN);
dobytes = TRANSBUFSIZE;
}
}
}
void gigaset_isoc_receive(unsigned char *src, unsigned count, struct bc_state *bcs)
{
switch (bcs->proto2) {
case ISDN_PROTO_L2_HDLC:
hdlc_unpack(src, count, bcs);
break;
default: /* assume transparent */
trans_receive(src, count, bcs);
}
}
/* == data input =========================================================== */
static void cmd_loop(unsigned char *src, int numbytes, struct inbuf_t *inbuf)
{
struct cardstate *cs = inbuf->cs;
unsigned cbytes = cs->cbytes;
while (numbytes--) {
/* copy next character, check for end of line */
switch (cs->respdata[cbytes] = *src++) {
case '\r':
case '\n':
/* end of line */
gig_dbg(DEBUG_TRANSCMD, "%s: End of Command (%d Bytes)",
__func__, cbytes);
cs->cbytes = cbytes;
gigaset_handle_modem_response(cs);
cbytes = 0;
break;
default:
/* advance in line buffer, checking for overflow */
if (cbytes < MAX_RESP_SIZE - 1)
cbytes++;
else
dev_warn(cs->dev, "response too large\n");
}
}
/* 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 = atomic_read(&inbuf->head);
while (head != (tail = atomic_read(&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 (atomic_read(&cs->mstate) == MS_LOCKED) {
gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response",
numbytes, src);
gigaset_if_receive(inbuf->cs, src, numbytes);
} else {
gigaset_dbg_buffer(DEBUG_CMD, "received response",
numbytes, src);
cmd_loop(src, numbytes, inbuf);
}
head += numbytes;
if (head == RBUFSIZE)
head = 0;
gig_dbg(DEBUG_INTR, "setting head to %u", head);
atomic_set(&inbuf->head, head);
}
}
/* == data output ========================================================== */
/* gigaset_send_skb
* called by common.c to queue an skb for sending
* and start transmission if necessary
* parameters:
* B Channel control structure
* skb
* return value:
* number of bytes accepted for sending
* (skb->len if ok, 0 if out of buffer space)
* or error code (< 0, eg. -EINVAL)
*/
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 */
}
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