X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Flib%2F842%2F842_compress.c;fp=kernel%2Flib%2F842%2F842_compress.c;h=4051339bdfbda6e6869d7f7c669672ba65f3d3f1;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=0000000000000000000000000000000000000000;hpb=f93b97fd65072de626c074dbe099a1fff05ce060;p=kvmfornfv.git diff --git a/kernel/lib/842/842_compress.c b/kernel/lib/842/842_compress.c new file mode 100644 index 000000000..4051339bd --- /dev/null +++ b/kernel/lib/842/842_compress.c @@ -0,0 +1,639 @@ +/* + * 842 Software Compression + * + * Copyright (C) 2015 Dan Streetman, IBM Corp + * + * 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. + * + * See 842.h for details of the 842 compressed format. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#define MODULE_NAME "842_compress" + +#include + +#include "842.h" +#include "842_debugfs.h" + +#define SW842_HASHTABLE8_BITS (10) +#define SW842_HASHTABLE4_BITS (11) +#define SW842_HASHTABLE2_BITS (10) + +/* By default, we allow compressing input buffers of any length, but we must + * use the non-standard "short data" template so the decompressor can correctly + * reproduce the uncompressed data buffer at the right length. However the + * hardware 842 compressor will not recognize the "short data" template, and + * will fail to decompress any compressed buffer containing it (I have no idea + * why anyone would want to use software to compress and hardware to decompress + * but that's beside the point). This parameter forces the compression + * function to simply reject any input buffer that isn't a multiple of 8 bytes + * long, instead of using the "short data" template, so that all compressed + * buffers produced by this function will be decompressable by the 842 hardware + * decompressor. Unless you have a specific need for that, leave this disabled + * so that any length buffer can be compressed. + */ +static bool sw842_strict; +module_param_named(strict, sw842_strict, bool, 0644); + +static u8 comp_ops[OPS_MAX][5] = { /* params size in bits */ + { I8, N0, N0, N0, 0x19 }, /* 8 */ + { I4, I4, N0, N0, 0x18 }, /* 18 */ + { I4, I2, I2, N0, 0x17 }, /* 25 */ + { I2, I2, I4, N0, 0x13 }, /* 25 */ + { I2, I2, I2, I2, 0x12 }, /* 32 */ + { I4, I2, D2, N0, 0x16 }, /* 33 */ + { I4, D2, I2, N0, 0x15 }, /* 33 */ + { I2, D2, I4, N0, 0x0e }, /* 33 */ + { D2, I2, I4, N0, 0x09 }, /* 33 */ + { I2, I2, I2, D2, 0x11 }, /* 40 */ + { I2, I2, D2, I2, 0x10 }, /* 40 */ + { I2, D2, I2, I2, 0x0d }, /* 40 */ + { D2, I2, I2, I2, 0x08 }, /* 40 */ + { I4, D4, N0, N0, 0x14 }, /* 41 */ + { D4, I4, N0, N0, 0x04 }, /* 41 */ + { I2, I2, D4, N0, 0x0f }, /* 48 */ + { I2, D2, I2, D2, 0x0c }, /* 48 */ + { I2, D4, I2, N0, 0x0b }, /* 48 */ + { D2, I2, I2, D2, 0x07 }, /* 48 */ + { D2, I2, D2, I2, 0x06 }, /* 48 */ + { D4, I2, I2, N0, 0x03 }, /* 48 */ + { I2, D2, D4, N0, 0x0a }, /* 56 */ + { D2, I2, D4, N0, 0x05 }, /* 56 */ + { D4, I2, D2, N0, 0x02 }, /* 56 */ + { D4, D2, I2, N0, 0x01 }, /* 56 */ + { D8, N0, N0, N0, 0x00 }, /* 64 */ +}; + +struct sw842_hlist_node8 { + struct hlist_node node; + u64 data; + u8 index; +}; + +struct sw842_hlist_node4 { + struct hlist_node node; + u32 data; + u16 index; +}; + +struct sw842_hlist_node2 { + struct hlist_node node; + u16 data; + u8 index; +}; + +#define INDEX_NOT_FOUND (-1) +#define INDEX_NOT_CHECKED (-2) + +struct sw842_param { + u8 *in; + u8 *instart; + u64 ilen; + u8 *out; + u64 olen; + u8 bit; + u64 data8[1]; + u32 data4[2]; + u16 data2[4]; + int index8[1]; + int index4[2]; + int index2[4]; + DECLARE_HASHTABLE(htable8, SW842_HASHTABLE8_BITS); + DECLARE_HASHTABLE(htable4, SW842_HASHTABLE4_BITS); + DECLARE_HASHTABLE(htable2, SW842_HASHTABLE2_BITS); + struct sw842_hlist_node8 node8[1 << I8_BITS]; + struct sw842_hlist_node4 node4[1 << I4_BITS]; + struct sw842_hlist_node2 node2[1 << I2_BITS]; +}; + +#define get_input_data(p, o, b) \ + be##b##_to_cpu(get_unaligned((__be##b *)((p)->in + (o)))) + +#define init_hashtable_nodes(p, b) do { \ + int _i; \ + hash_init((p)->htable##b); \ + for (_i = 0; _i < ARRAY_SIZE((p)->node##b); _i++) { \ + (p)->node##b[_i].index = _i; \ + (p)->node##b[_i].data = 0; \ + INIT_HLIST_NODE(&(p)->node##b[_i].node); \ + } \ +} while (0) + +#define find_index(p, b, n) ({ \ + struct sw842_hlist_node##b *_n; \ + p->index##b[n] = INDEX_NOT_FOUND; \ + hash_for_each_possible(p->htable##b, _n, node, p->data##b[n]) { \ + if (p->data##b[n] == _n->data) { \ + p->index##b[n] = _n->index; \ + break; \ + } \ + } \ + p->index##b[n] >= 0; \ +}) + +#define check_index(p, b, n) \ + ((p)->index##b[n] == INDEX_NOT_CHECKED \ + ? find_index(p, b, n) \ + : (p)->index##b[n] >= 0) + +#define replace_hash(p, b, i, d) do { \ + struct sw842_hlist_node##b *_n = &(p)->node##b[(i)+(d)]; \ + hash_del(&_n->node); \ + _n->data = (p)->data##b[d]; \ + pr_debug("add hash index%x %x pos %x data %lx\n", b, \ + (unsigned int)_n->index, \ + (unsigned int)((p)->in - (p)->instart), \ + (unsigned long)_n->data); \ + hash_add((p)->htable##b, &_n->node, _n->data); \ +} while (0) + +static u8 bmask[8] = { 0x00, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe }; + +static int add_bits(struct sw842_param *p, u64 d, u8 n); + +static int __split_add_bits(struct sw842_param *p, u64 d, u8 n, u8 s) +{ + int ret; + + if (n <= s) + return -EINVAL; + + ret = add_bits(p, d >> s, n - s); + if (ret) + return ret; + return add_bits(p, d & GENMASK_ULL(s - 1, 0), s); +} + +static int add_bits(struct sw842_param *p, u64 d, u8 n) +{ + int b = p->bit, bits = b + n, s = round_up(bits, 8) - bits; + u64 o; + u8 *out = p->out; + + pr_debug("add %u bits %lx\n", (unsigned char)n, (unsigned long)d); + + if (n > 64) + return -EINVAL; + + /* split this up if writing to > 8 bytes (i.e. n == 64 && p->bit > 0), + * or if we're at the end of the output buffer and would write past end + */ + if (bits > 64) + return __split_add_bits(p, d, n, 32); + else if (p->olen < 8 && bits > 32 && bits <= 56) + return __split_add_bits(p, d, n, 16); + else if (p->olen < 4 && bits > 16 && bits <= 24) + return __split_add_bits(p, d, n, 8); + + if (DIV_ROUND_UP(bits, 8) > p->olen) + return -ENOSPC; + + o = *out & bmask[b]; + d <<= s; + + if (bits <= 8) + *out = o | d; + else if (bits <= 16) + put_unaligned(cpu_to_be16(o << 8 | d), (__be16 *)out); + else if (bits <= 24) + put_unaligned(cpu_to_be32(o << 24 | d << 8), (__be32 *)out); + else if (bits <= 32) + put_unaligned(cpu_to_be32(o << 24 | d), (__be32 *)out); + else if (bits <= 40) + put_unaligned(cpu_to_be64(o << 56 | d << 24), (__be64 *)out); + else if (bits <= 48) + put_unaligned(cpu_to_be64(o << 56 | d << 16), (__be64 *)out); + else if (bits <= 56) + put_unaligned(cpu_to_be64(o << 56 | d << 8), (__be64 *)out); + else + put_unaligned(cpu_to_be64(o << 56 | d), (__be64 *)out); + + p->bit += n; + + if (p->bit > 7) { + p->out += p->bit / 8; + p->olen -= p->bit / 8; + p->bit %= 8; + } + + return 0; +} + +static int add_template(struct sw842_param *p, u8 c) +{ + int ret, i, b = 0; + u8 *t = comp_ops[c]; + bool inv = false; + + if (c >= OPS_MAX) + return -EINVAL; + + pr_debug("template %x\n", t[4]); + + ret = add_bits(p, t[4], OP_BITS); + if (ret) + return ret; + + for (i = 0; i < 4; i++) { + pr_debug("op %x\n", t[i]); + + switch (t[i] & OP_AMOUNT) { + case OP_AMOUNT_8: + if (b) + inv = true; + else if (t[i] & OP_ACTION_INDEX) + ret = add_bits(p, p->index8[0], I8_BITS); + else if (t[i] & OP_ACTION_DATA) + ret = add_bits(p, p->data8[0], 64); + else + inv = true; + break; + case OP_AMOUNT_4: + if (b == 2 && t[i] & OP_ACTION_DATA) + ret = add_bits(p, get_input_data(p, 2, 32), 32); + else if (b != 0 && b != 4) + inv = true; + else if (t[i] & OP_ACTION_INDEX) + ret = add_bits(p, p->index4[b >> 2], I4_BITS); + else if (t[i] & OP_ACTION_DATA) + ret = add_bits(p, p->data4[b >> 2], 32); + else + inv = true; + break; + case OP_AMOUNT_2: + if (b != 0 && b != 2 && b != 4 && b != 6) + inv = true; + if (t[i] & OP_ACTION_INDEX) + ret = add_bits(p, p->index2[b >> 1], I2_BITS); + else if (t[i] & OP_ACTION_DATA) + ret = add_bits(p, p->data2[b >> 1], 16); + else + inv = true; + break; + case OP_AMOUNT_0: + inv = (b != 8) || !(t[i] & OP_ACTION_NOOP); + break; + default: + inv = true; + break; + } + + if (ret) + return ret; + + if (inv) { + pr_err("Invalid templ %x op %d : %x %x %x %x\n", + c, i, t[0], t[1], t[2], t[3]); + return -EINVAL; + } + + b += t[i] & OP_AMOUNT; + } + + if (b != 8) { + pr_err("Invalid template %x len %x : %x %x %x %x\n", + c, b, t[0], t[1], t[2], t[3]); + return -EINVAL; + } + + if (sw842_template_counts) + atomic_inc(&template_count[t[4]]); + + return 0; +} + +static int add_repeat_template(struct sw842_param *p, u8 r) +{ + int ret; + + /* repeat param is 0-based */ + if (!r || --r > REPEAT_BITS_MAX) + return -EINVAL; + + ret = add_bits(p, OP_REPEAT, OP_BITS); + if (ret) + return ret; + + ret = add_bits(p, r, REPEAT_BITS); + if (ret) + return ret; + + if (sw842_template_counts) + atomic_inc(&template_repeat_count); + + return 0; +} + +static int add_short_data_template(struct sw842_param *p, u8 b) +{ + int ret, i; + + if (!b || b > SHORT_DATA_BITS_MAX) + return -EINVAL; + + ret = add_bits(p, OP_SHORT_DATA, OP_BITS); + if (ret) + return ret; + + ret = add_bits(p, b, SHORT_DATA_BITS); + if (ret) + return ret; + + for (i = 0; i < b; i++) { + ret = add_bits(p, p->in[i], 8); + if (ret) + return ret; + } + + if (sw842_template_counts) + atomic_inc(&template_short_data_count); + + return 0; +} + +static int add_zeros_template(struct sw842_param *p) +{ + int ret = add_bits(p, OP_ZEROS, OP_BITS); + + if (ret) + return ret; + + if (sw842_template_counts) + atomic_inc(&template_zeros_count); + + return 0; +} + +static int add_end_template(struct sw842_param *p) +{ + int ret = add_bits(p, OP_END, OP_BITS); + + if (ret) + return ret; + + if (sw842_template_counts) + atomic_inc(&template_end_count); + + return 0; +} + +static bool check_template(struct sw842_param *p, u8 c) +{ + u8 *t = comp_ops[c]; + int i, match, b = 0; + + if (c >= OPS_MAX) + return false; + + for (i = 0; i < 4; i++) { + if (t[i] & OP_ACTION_INDEX) { + if (t[i] & OP_AMOUNT_2) + match = check_index(p, 2, b >> 1); + else if (t[i] & OP_AMOUNT_4) + match = check_index(p, 4, b >> 2); + else if (t[i] & OP_AMOUNT_8) + match = check_index(p, 8, 0); + else + return false; + if (!match) + return false; + } + + b += t[i] & OP_AMOUNT; + } + + return true; +} + +static void get_next_data(struct sw842_param *p) +{ + p->data8[0] = get_input_data(p, 0, 64); + p->data4[0] = get_input_data(p, 0, 32); + p->data4[1] = get_input_data(p, 4, 32); + p->data2[0] = get_input_data(p, 0, 16); + p->data2[1] = get_input_data(p, 2, 16); + p->data2[2] = get_input_data(p, 4, 16); + p->data2[3] = get_input_data(p, 6, 16); +} + +/* update the hashtable entries. + * only call this after finding/adding the current template + * the dataN fields for the current 8 byte block must be already updated + */ +static void update_hashtables(struct sw842_param *p) +{ + u64 pos = p->in - p->instart; + u64 n8 = (pos >> 3) % (1 << I8_BITS); + u64 n4 = (pos >> 2) % (1 << I4_BITS); + u64 n2 = (pos >> 1) % (1 << I2_BITS); + + replace_hash(p, 8, n8, 0); + replace_hash(p, 4, n4, 0); + replace_hash(p, 4, n4, 1); + replace_hash(p, 2, n2, 0); + replace_hash(p, 2, n2, 1); + replace_hash(p, 2, n2, 2); + replace_hash(p, 2, n2, 3); +} + +/* find the next template to use, and add it + * the p->dataN fields must already be set for the current 8 byte block + */ +static int process_next(struct sw842_param *p) +{ + int ret, i; + + p->index8[0] = INDEX_NOT_CHECKED; + p->index4[0] = INDEX_NOT_CHECKED; + p->index4[1] = INDEX_NOT_CHECKED; + p->index2[0] = INDEX_NOT_CHECKED; + p->index2[1] = INDEX_NOT_CHECKED; + p->index2[2] = INDEX_NOT_CHECKED; + p->index2[3] = INDEX_NOT_CHECKED; + + /* check up to OPS_MAX - 1; last op is our fallback */ + for (i = 0; i < OPS_MAX - 1; i++) { + if (check_template(p, i)) + break; + } + + ret = add_template(p, i); + if (ret) + return ret; + + return 0; +} + +/** + * sw842_compress + * + * Compress the uncompressed buffer of length @ilen at @in to the output buffer + * @out, using no more than @olen bytes, using the 842 compression format. + * + * 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_compress(const u8 *in, unsigned int ilen, + u8 *out, unsigned int *olen, void *wmem) +{ + struct sw842_param *p = (struct sw842_param *)wmem; + int ret; + u64 last, next, pad, total; + u8 repeat_count = 0; + u32 crc; + + BUILD_BUG_ON(sizeof(*p) > SW842_MEM_COMPRESS); + + init_hashtable_nodes(p, 8); + init_hashtable_nodes(p, 4); + init_hashtable_nodes(p, 2); + + p->in = (u8 *)in; + p->instart = p->in; + p->ilen = ilen; + p->out = out; + p->olen = *olen; + p->bit = 0; + + total = p->olen; + + *olen = 0; + + /* if using strict mode, we can only compress a multiple of 8 */ + if (sw842_strict && (ilen % 8)) { + pr_err("Using strict mode, can't compress len %d\n", ilen); + return -EINVAL; + } + + /* let's compress at least 8 bytes, mkay? */ + if (unlikely(ilen < 8)) + goto skip_comp; + + /* make initial 'last' different so we don't match the first time */ + last = ~get_unaligned((u64 *)p->in); + + while (p->ilen > 7) { + next = get_unaligned((u64 *)p->in); + + /* must get the next data, as we need to update the hashtable + * entries with the new data every time + */ + get_next_data(p); + + /* we don't care about endianness in last or next; + * we're just comparing 8 bytes to another 8 bytes, + * they're both the same endianness + */ + if (next == last) { + /* repeat count bits are 0-based, so we stop at +1 */ + if (++repeat_count <= REPEAT_BITS_MAX) + goto repeat; + } + if (repeat_count) { + ret = add_repeat_template(p, repeat_count); + repeat_count = 0; + if (next == last) /* reached max repeat bits */ + goto repeat; + } + + if (next == 0) + ret = add_zeros_template(p); + else + ret = process_next(p); + + if (ret) + return ret; + +repeat: + last = next; + update_hashtables(p); + p->in += 8; + p->ilen -= 8; + } + + if (repeat_count) { + ret = add_repeat_template(p, repeat_count); + if (ret) + return ret; + } + +skip_comp: + if (p->ilen > 0) { + ret = add_short_data_template(p, p->ilen); + if (ret) + return ret; + + p->in += p->ilen; + p->ilen = 0; + } + + ret = add_end_template(p); + if (ret) + return ret; + + /* + * crc(0:31) is appended to target data starting with the next + * bit after End of stream template. + * nx842 calculates CRC for data in big-endian format. So doing + * same here so that sw842 decompression can be used for both + * compressed data. + */ + crc = crc32_be(0, in, ilen); + ret = add_bits(p, crc, CRC_BITS); + if (ret) + return ret; + + if (p->bit) { + p->out++; + p->olen--; + p->bit = 0; + } + + /* pad compressed length to multiple of 8 */ + pad = (8 - ((total - p->olen) % 8)) % 8; + if (pad) { + if (pad > p->olen) /* we were so close! */ + return -ENOSPC; + memset(p->out, 0, pad); + p->out += pad; + p->olen -= pad; + } + + if (unlikely((total - p->olen) > UINT_MAX)) + return -ENOSPC; + + *olen = total - p->olen; + + return 0; +} +EXPORT_SYMBOL_GPL(sw842_compress); + +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 Compressor"); +MODULE_AUTHOR("Dan Streetman ");