linux/lib/842/842_decompress.c
Thomas Gleixner c942fddf87 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
Based on 3 normalized pattern(s):

  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 this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

  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 [author] [kishon] [vijay] [abraham]
  [i] [kishon]@[ti] [com] this program is distributed in the hope that
  it will be useful but without any warranty without even the implied
  warranty of merchantability or fitness for a particular purpose see
  the gnu general public license for more details

  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 [author] [graeme] [gregory]
  [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
  [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
  [hk] [hemahk]@[ti] [com] this program is distributed in the hope
  that it will be useful but without any warranty without even the
  implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:37 -07:00

418 lines
8.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 842 Software Decompression
*
* Copyright (C) 2015 Dan Streetman, IBM Corp
*
* See 842.h for details of the 842 compressed format.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#define MODULE_NAME "842_decompress"
#include "842.h"
#include "842_debugfs.h"
/* rolling fifo sizes */
#define I2_FIFO_SIZE (2 * (1 << I2_BITS))
#define I4_FIFO_SIZE (4 * (1 << I4_BITS))
#define I8_FIFO_SIZE (8 * (1 << I8_BITS))
static u8 decomp_ops[OPS_MAX][4] = {
{ D8, N0, N0, N0 },
{ D4, D2, I2, N0 },
{ D4, I2, D2, N0 },
{ D4, I2, I2, N0 },
{ D4, I4, N0, N0 },
{ D2, I2, D4, N0 },
{ D2, I2, D2, I2 },
{ D2, I2, I2, D2 },
{ D2, I2, I2, I2 },
{ D2, I2, I4, N0 },
{ I2, D2, D4, N0 },
{ I2, D4, I2, N0 },
{ I2, D2, I2, D2 },
{ I2, D2, I2, I2 },
{ I2, D2, I4, N0 },
{ I2, I2, D4, N0 },
{ I2, I2, D2, I2 },
{ I2, I2, I2, D2 },
{ I2, I2, I2, I2 },
{ I2, I2, I4, N0 },
{ I4, D4, N0, N0 },
{ I4, D2, I2, N0 },
{ I4, I2, D2, N0 },
{ I4, I2, I2, N0 },
{ I4, I4, N0, N0 },
{ I8, N0, N0, N0 }
};
struct sw842_param {
u8 *in;
u8 bit;
u64 ilen;
u8 *out;
u8 *ostart;
u64 olen;
};
#define beN_to_cpu(d, s) \
((s) == 2 ? be16_to_cpu(get_unaligned((__be16 *)d)) : \
(s) == 4 ? be32_to_cpu(get_unaligned((__be32 *)d)) : \
(s) == 8 ? be64_to_cpu(get_unaligned((__be64 *)d)) : \
0)
static int next_bits(struct sw842_param *p, u64 *d, u8 n);
static int __split_next_bits(struct sw842_param *p, u64 *d, u8 n, u8 s)
{
u64 tmp = 0;
int ret;
if (n <= s) {
pr_debug("split_next_bits invalid n %u s %u\n", n, s);
return -EINVAL;
}
ret = next_bits(p, &tmp, n - s);
if (ret)
return ret;
ret = next_bits(p, d, s);
if (ret)
return ret;
*d |= tmp << s;
return 0;
}
static int next_bits(struct sw842_param *p, u64 *d, u8 n)
{
u8 *in = p->in, b = p->bit, bits = b + n;
if (n > 64) {
pr_debug("next_bits invalid n %u\n", n);
return -EINVAL;
}
/* split this up if reading > 8 bytes, or if we're at the end of
* the input buffer and would read past the end
*/
if (bits > 64)
return __split_next_bits(p, d, n, 32);
else if (p->ilen < 8 && bits > 32 && bits <= 56)
return __split_next_bits(p, d, n, 16);
else if (p->ilen < 4 && bits > 16 && bits <= 24)
return __split_next_bits(p, d, n, 8);
if (DIV_ROUND_UP(bits, 8) > p->ilen)
return -EOVERFLOW;
if (bits <= 8)
*d = *in >> (8 - bits);
else if (bits <= 16)
*d = be16_to_cpu(get_unaligned((__be16 *)in)) >> (16 - bits);
else if (bits <= 32)
*d = be32_to_cpu(get_unaligned((__be32 *)in)) >> (32 - bits);
else
*d = be64_to_cpu(get_unaligned((__be64 *)in)) >> (64 - bits);
*d &= GENMASK_ULL(n - 1, 0);
p->bit += n;
if (p->bit > 7) {
p->in += p->bit / 8;
p->ilen -= p->bit / 8;
p->bit %= 8;
}
return 0;
}
static int do_data(struct sw842_param *p, u8 n)
{
u64 v;
int ret;
if (n > p->olen)
return -ENOSPC;
ret = next_bits(p, &v, n * 8);
if (ret)
return ret;
switch (n) {
case 2:
put_unaligned(cpu_to_be16((u16)v), (__be16 *)p->out);
break;
case 4:
put_unaligned(cpu_to_be32((u32)v), (__be32 *)p->out);
break;
case 8:
put_unaligned(cpu_to_be64((u64)v), (__be64 *)p->out);
break;
default:
return -EINVAL;
}
p->out += n;
p->olen -= n;
return 0;
}
static int __do_index(struct sw842_param *p, u8 size, u8 bits, u64 fsize)
{
u64 index, offset, total = round_down(p->out - p->ostart, 8);
int ret;
ret = next_bits(p, &index, bits);
if (ret)
return ret;
offset = index * size;
/* a ring buffer of fsize is used; correct the offset */
if (total > fsize) {
/* this is where the current fifo is */
u64 section = round_down(total, fsize);
/* the current pos in the fifo */
u64 pos = total - section;
/* if the offset is past/at the pos, we need to
* go back to the last fifo section
*/
if (offset >= pos)
section -= fsize;
offset += section;
}
if (offset + size > total) {
pr_debug("index%x %lx points past end %lx\n", size,
(unsigned long)offset, (unsigned long)total);
return -EINVAL;
}
if (size != 2 && size != 4 && size != 8)
WARN(1, "__do_index invalid size %x\n", size);
else
pr_debug("index%x to %lx off %lx adjoff %lx tot %lx data %lx\n",
size, (unsigned long)index,
(unsigned long)(index * size), (unsigned long)offset,
(unsigned long)total,
(unsigned long)beN_to_cpu(&p->ostart[offset], size));
memcpy(p->out, &p->ostart[offset], size);
p->out += size;
p->olen -= size;
return 0;
}
static int do_index(struct sw842_param *p, u8 n)
{
switch (n) {
case 2:
return __do_index(p, 2, I2_BITS, I2_FIFO_SIZE);
case 4:
return __do_index(p, 4, I4_BITS, I4_FIFO_SIZE);
case 8:
return __do_index(p, 8, I8_BITS, I8_FIFO_SIZE);
default:
return -EINVAL;
}
}
static int do_op(struct sw842_param *p, u8 o)
{
int i, ret = 0;
if (o >= OPS_MAX)
return -EINVAL;
for (i = 0; i < 4; i++) {
u8 op = decomp_ops[o][i];
pr_debug("op is %x\n", op);
switch (op & OP_ACTION) {
case OP_ACTION_DATA:
ret = do_data(p, op & OP_AMOUNT);
break;
case OP_ACTION_INDEX:
ret = do_index(p, op & OP_AMOUNT);
break;
case OP_ACTION_NOOP:
break;
default:
pr_err("Internal error, invalid op %x\n", op);
return -EINVAL;
}
if (ret)
return ret;
}
if (sw842_template_counts)
atomic_inc(&template_count[o]);
return 0;
}
/**
* sw842_decompress
*
* Decompress the 842-compressed buffer of length @ilen at @in
* to the output buffer @out, using no more than @olen bytes.
*
* The compressed buffer must be only a single 842-compressed buffer,
* with the standard format described in the comments in 842.h
* Processing will stop when the 842 "END" template is detected,
* not the end of the buffer.
*
* Returns: 0 on success, error on failure. The @olen parameter
* will contain the number of output bytes written on success, or
* 0 on error.
*/
int sw842_decompress(const u8 *in, unsigned int ilen,
u8 *out, unsigned int *olen)
{
struct sw842_param p;
int ret;
u64 op, rep, tmp, bytes, total;
u64 crc;
p.in = (u8 *)in;
p.bit = 0;
p.ilen = ilen;
p.out = out;
p.ostart = out;
p.olen = *olen;
total = p.olen;
*olen = 0;
do {
ret = next_bits(&p, &op, OP_BITS);
if (ret)
return ret;
pr_debug("template is %lx\n", (unsigned long)op);
switch (op) {
case OP_REPEAT:
ret = next_bits(&p, &rep, REPEAT_BITS);
if (ret)
return ret;
if (p.out == out) /* no previous bytes */
return -EINVAL;
/* copy rep + 1 */
rep++;
if (rep * 8 > p.olen)
return -ENOSPC;
while (rep-- > 0) {
memcpy(p.out, p.out - 8, 8);
p.out += 8;
p.olen -= 8;
}
if (sw842_template_counts)
atomic_inc(&template_repeat_count);
break;
case OP_ZEROS:
if (8 > p.olen)
return -ENOSPC;
memset(p.out, 0, 8);
p.out += 8;
p.olen -= 8;
if (sw842_template_counts)
atomic_inc(&template_zeros_count);
break;
case OP_SHORT_DATA:
ret = next_bits(&p, &bytes, SHORT_DATA_BITS);
if (ret)
return ret;
if (!bytes || bytes > SHORT_DATA_BITS_MAX)
return -EINVAL;
while (bytes-- > 0) {
ret = next_bits(&p, &tmp, 8);
if (ret)
return ret;
*p.out = (u8)tmp;
p.out++;
p.olen--;
}
if (sw842_template_counts)
atomic_inc(&template_short_data_count);
break;
case OP_END:
if (sw842_template_counts)
atomic_inc(&template_end_count);
break;
default: /* use template */
ret = do_op(&p, op);
if (ret)
return ret;
break;
}
} while (op != OP_END);
/*
* crc(0:31) is saved in compressed data starting with the
* next bit after End of stream template.
*/
ret = next_bits(&p, &crc, CRC_BITS);
if (ret)
return ret;
/*
* Validate CRC saved in compressed data.
*/
if (crc != (u64)crc32_be(0, out, total - p.olen)) {
pr_debug("CRC mismatch for decompression\n");
return -EINVAL;
}
if (unlikely((total - p.olen) > UINT_MAX))
return -ENOSPC;
*olen = total - p.olen;
return 0;
}
EXPORT_SYMBOL_GPL(sw842_decompress);
static int __init sw842_init(void)
{
if (sw842_template_counts)
sw842_debugfs_create();
return 0;
}
module_init(sw842_init);
static void __exit sw842_exit(void)
{
if (sw842_template_counts)
sw842_debugfs_remove();
}
module_exit(sw842_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Software 842 Decompressor");
MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");