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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/misc/altera-stapl/altera-comp.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/misc/altera-stapl/altera-comp.c')
-rw-r--r-- | drivers/misc/altera-stapl/altera-comp.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/drivers/misc/altera-stapl/altera-comp.c b/drivers/misc/altera-stapl/altera-comp.c new file mode 100644 index 000000000..4a63f51cc --- /dev/null +++ b/drivers/misc/altera-stapl/altera-comp.c @@ -0,0 +1,128 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * altera-comp.c + * + * altera FPGA driver + * + * Copyright (C) Altera Corporation 1998-2001 + * Copyright (C) 2010 NetUP Inc. + * Copyright (C) 2010 Igor M. Liplianin <liplianin@netup.ru> + */ + +#include <linux/kernel.h> +#include "altera-exprt.h" + +#define SHORT_BITS 16 +#define CHAR_BITS 8 +#define DATA_BLOB_LENGTH 3 +#define MATCH_DATA_LENGTH 8192 +#define ALTERA_REQUEST_SIZE 1024 +#define ALTERA_BUFFER_SIZE (MATCH_DATA_LENGTH + ALTERA_REQUEST_SIZE) + +static u32 altera_bits_req(u32 n) +{ + u32 result = SHORT_BITS; + + if (n == 0) + result = 1; + else { + /* Look for the highest non-zero bit position */ + while ((n & (1 << (SHORT_BITS - 1))) == 0) { + n <<= 1; + --result; + } + } + + return result; +} + +static u32 altera_read_packed(u8 *buffer, u32 bits, u32 *bits_avail, + u32 *in_index) +{ + u32 result = 0; + u32 shift = 0; + u32 databyte = 0; + + while (bits > 0) { + databyte = buffer[*in_index]; + result |= (((databyte >> (CHAR_BITS - *bits_avail)) + & (0xff >> (CHAR_BITS - *bits_avail))) << shift); + + if (bits <= *bits_avail) { + result &= (0xffff >> (SHORT_BITS - (bits + shift))); + *bits_avail -= bits; + bits = 0; + } else { + ++(*in_index); + shift += *bits_avail; + bits -= *bits_avail; + *bits_avail = CHAR_BITS; + } + } + + return result; +} + +u32 altera_shrink(u8 *in, u32 in_length, u8 *out, u32 out_length, s32 version) +{ + u32 i, j, data_length = 0L; + u32 offset, length; + u32 match_data_length = MATCH_DATA_LENGTH; + u32 bits_avail = CHAR_BITS; + u32 in_index = 0L; + + if (version > 0) + --match_data_length; + + for (i = 0; i < out_length; ++i) + out[i] = 0; + + /* Read number of bytes in data. */ + for (i = 0; i < sizeof(in_length); ++i) { + data_length = data_length | ( + altera_read_packed(in, + CHAR_BITS, + &bits_avail, + &in_index) << (i * CHAR_BITS)); + } + + if (data_length > out_length) { + data_length = 0L; + return data_length; + } + + i = 0; + while (i < data_length) { + /* A 0 bit indicates literal data. */ + if (altera_read_packed(in, 1, &bits_avail, + &in_index) == 0) { + for (j = 0; j < DATA_BLOB_LENGTH; ++j) { + if (i < data_length) { + out[i] = (u8)altera_read_packed(in, + CHAR_BITS, + &bits_avail, + &in_index); + i++; + } + } + } else { + /* A 1 bit indicates offset/length to follow. */ + offset = altera_read_packed(in, altera_bits_req((s16) + (i > match_data_length ? + match_data_length : i)), + &bits_avail, + &in_index); + length = altera_read_packed(in, CHAR_BITS, + &bits_avail, + &in_index); + for (j = 0; j < length; ++j) { + if (i < data_length) { + out[i] = out[i - offset]; + i++; + } + } + } + } + + return data_length; +} |