diff options
Diffstat (limited to 'lib/zlib_dfltcc/dfltcc_deflate.c')
| -rw-r--r-- | lib/zlib_dfltcc/dfltcc_deflate.c | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/lib/zlib_dfltcc/dfltcc_deflate.c b/lib/zlib_dfltcc/dfltcc_deflate.c new file mode 100644 index 0000000000..b732b6d9e3 --- /dev/null +++ b/lib/zlib_dfltcc/dfltcc_deflate.c @@ -0,0 +1,313 @@ +// SPDX-License-Identifier: Zlib + +#include "../zlib_deflate/defutil.h" +#include "dfltcc_util.h" +#include "dfltcc_deflate.h" +#include <asm/setup.h> +#include <linux/export.h> +#include <linux/zutil.h> + +#define GET_DFLTCC_DEFLATE_STATE(state) ((struct dfltcc_deflate_state *)GET_DFLTCC_STATE(state)) + +/* + * Compress. + */ +int dfltcc_can_deflate( + z_streamp strm +) +{ + deflate_state *state = (deflate_state *)strm->state; + struct dfltcc_deflate_state *dfltcc_state = GET_DFLTCC_DEFLATE_STATE(state); + + /* Check for kernel dfltcc command line parameter */ + if (zlib_dfltcc_support == ZLIB_DFLTCC_DISABLED || + zlib_dfltcc_support == ZLIB_DFLTCC_INFLATE_ONLY) + return 0; + + /* Unsupported compression settings */ + if (!dfltcc_are_params_ok(state->level, state->w_bits, state->strategy, + dfltcc_state->level_mask)) + return 0; + + /* Unsupported hardware */ + if (!is_bit_set(dfltcc_state->common.af.fns, DFLTCC_GDHT) || + !is_bit_set(dfltcc_state->common.af.fns, DFLTCC_CMPR) || + !is_bit_set(dfltcc_state->common.af.fmts, DFLTCC_FMT0)) + return 0; + + return 1; +} +EXPORT_SYMBOL(dfltcc_can_deflate); + +void dfltcc_reset_deflate_state(z_streamp strm) { + deflate_state *state = (deflate_state *)strm->state; + struct dfltcc_deflate_state *dfltcc_state = GET_DFLTCC_DEFLATE_STATE(state); + + dfltcc_reset_state(&dfltcc_state->common); + + /* Initialize tuning parameters */ + if (zlib_dfltcc_support == ZLIB_DFLTCC_FULL_DEBUG) + dfltcc_state->level_mask = DFLTCC_LEVEL_MASK_DEBUG; + else + dfltcc_state->level_mask = DFLTCC_LEVEL_MASK; + dfltcc_state->block_size = DFLTCC_BLOCK_SIZE; + dfltcc_state->block_threshold = DFLTCC_FIRST_FHT_BLOCK_SIZE; + dfltcc_state->dht_threshold = DFLTCC_DHT_MIN_SAMPLE_SIZE; +} +EXPORT_SYMBOL(dfltcc_reset_deflate_state); + +static void dfltcc_gdht( + z_streamp strm +) +{ + deflate_state *state = (deflate_state *)strm->state; + struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param; + size_t avail_in = strm->avail_in; + + dfltcc(DFLTCC_GDHT, + param, NULL, NULL, + &strm->next_in, &avail_in, NULL); +} + +static dfltcc_cc dfltcc_cmpr( + z_streamp strm +) +{ + deflate_state *state = (deflate_state *)strm->state; + struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param; + size_t avail_in = strm->avail_in; + size_t avail_out = strm->avail_out; + dfltcc_cc cc; + + cc = dfltcc(DFLTCC_CMPR | HBT_CIRCULAR, + param, &strm->next_out, &avail_out, + &strm->next_in, &avail_in, state->window); + strm->total_in += (strm->avail_in - avail_in); + strm->total_out += (strm->avail_out - avail_out); + strm->avail_in = avail_in; + strm->avail_out = avail_out; + return cc; +} + +static void send_eobs( + z_streamp strm, + const struct dfltcc_param_v0 *param +) +{ + deflate_state *state = (deflate_state *)strm->state; + + zlib_tr_send_bits( + state, + bi_reverse(param->eobs >> (15 - param->eobl), param->eobl), + param->eobl); + flush_pending(strm); + if (state->pending != 0) { + /* The remaining data is located in pending_out[0:pending]. If someone + * calls put_byte() - this might happen in deflate() - the byte will be + * placed into pending_buf[pending], which is incorrect. Move the + * remaining data to the beginning of pending_buf so that put_byte() is + * usable again. + */ + memmove(state->pending_buf, state->pending_out, state->pending); + state->pending_out = state->pending_buf; + } +#ifdef ZLIB_DEBUG + state->compressed_len += param->eobl; +#endif +} + +int dfltcc_deflate( + z_streamp strm, + int flush, + block_state *result +) +{ + deflate_state *state = (deflate_state *)strm->state; + struct dfltcc_deflate_state *dfltcc_state = GET_DFLTCC_DEFLATE_STATE(state); + struct dfltcc_param_v0 *param = &dfltcc_state->common.param; + uInt masked_avail_in; + dfltcc_cc cc; + int need_empty_block; + int soft_bcc; + int no_flush; + + if (!dfltcc_can_deflate(strm)) { + /* Clear history. */ + if (flush == Z_FULL_FLUSH) + param->hl = 0; + return 0; + } + +again: + masked_avail_in = 0; + soft_bcc = 0; + no_flush = flush == Z_NO_FLUSH; + + /* No input data. Return, except when Continuation Flag is set, which means + * that DFLTCC has buffered some output in the parameter block and needs to + * be called again in order to flush it. + */ + if (strm->avail_in == 0 && !param->cf) { + /* A block is still open, and the hardware does not support closing + * blocks without adding data. Thus, close it manually. + */ + if (!no_flush && param->bcf) { + send_eobs(strm, param); + param->bcf = 0; + } + /* Let one of deflate_* functions write a trailing empty block. */ + if (flush == Z_FINISH) + return 0; + /* Clear history. */ + if (flush == Z_FULL_FLUSH) + param->hl = 0; + /* Trigger block post-processing if necessary. */ + *result = no_flush ? need_more : block_done; + return 1; + } + + /* There is an open non-BFINAL block, we are not going to close it just + * yet, we have compressed more than DFLTCC_BLOCK_SIZE bytes and we see + * more than DFLTCC_DHT_MIN_SAMPLE_SIZE bytes. Open a new block with a new + * DHT in order to adapt to a possibly changed input data distribution. + */ + if (param->bcf && no_flush && + strm->total_in > dfltcc_state->block_threshold && + strm->avail_in >= dfltcc_state->dht_threshold) { + if (param->cf) { + /* We need to flush the DFLTCC buffer before writing the + * End-of-block Symbol. Mask the input data and proceed as usual. + */ + masked_avail_in += strm->avail_in; + strm->avail_in = 0; + no_flush = 0; + } else { + /* DFLTCC buffer is empty, so we can manually write the + * End-of-block Symbol right away. + */ + send_eobs(strm, param); + param->bcf = 0; + dfltcc_state->block_threshold = + strm->total_in + dfltcc_state->block_size; + } + } + + /* No space for compressed data. If we proceed, dfltcc_cmpr() will return + * DFLTCC_CC_OP1_TOO_SHORT without buffering header bits, but we will still + * set BCF=1, which is wrong. Avoid complications and return early. + */ + if (strm->avail_out == 0) { + *result = need_more; + return 1; + } + + /* The caller gave us too much data. Pass only one block worth of + * uncompressed data to DFLTCC and mask the rest, so that on the next + * iteration we start a new block. + */ + if (no_flush && strm->avail_in > dfltcc_state->block_size) { + masked_avail_in += (strm->avail_in - dfltcc_state->block_size); + strm->avail_in = dfltcc_state->block_size; + } + + /* When we have an open non-BFINAL deflate block and caller indicates that + * the stream is ending, we need to close an open deflate block and open a + * BFINAL one. + */ + need_empty_block = flush == Z_FINISH && param->bcf && !param->bhf; + + /* Translate stream to parameter block */ + param->cvt = CVT_ADLER32; + if (!no_flush) + /* We need to close a block. Always do this in software - when there is + * no input data, the hardware will not hohor BCC. */ + soft_bcc = 1; + if (flush == Z_FINISH && !param->bcf) + /* We are about to open a BFINAL block, set Block Header Final bit + * until the stream ends. + */ + param->bhf = 1; + /* DFLTCC-CMPR will write to next_out, so make sure that buffers with + * higher precedence are empty. + */ + Assert(state->pending == 0, "There must be no pending bytes"); + Assert(state->bi_valid < 8, "There must be less than 8 pending bits"); + param->sbb = (unsigned int)state->bi_valid; + if (param->sbb > 0) + *strm->next_out = (Byte)state->bi_buf; + /* Honor history and check value */ + param->nt = 0; + param->cv = strm->adler; + + /* When opening a block, choose a Huffman-Table Type */ + if (!param->bcf) { + if (strm->total_in == 0 && dfltcc_state->block_threshold > 0) { + param->htt = HTT_FIXED; + } + else { + param->htt = HTT_DYNAMIC; + dfltcc_gdht(strm); + } + } + + /* Deflate */ + do { + cc = dfltcc_cmpr(strm); + if (strm->avail_in < 4096 && masked_avail_in > 0) + /* We are about to call DFLTCC with a small input buffer, which is + * inefficient. Since there is masked data, there will be at least + * one more DFLTCC call, so skip the current one and make the next + * one handle more data. + */ + break; + } while (cc == DFLTCC_CC_AGAIN); + + /* Translate parameter block to stream */ + strm->msg = oesc_msg(dfltcc_state->common.msg, param->oesc); + state->bi_valid = param->sbb; + if (state->bi_valid == 0) + state->bi_buf = 0; /* Avoid accessing next_out */ + else + state->bi_buf = *strm->next_out & ((1 << state->bi_valid) - 1); + strm->adler = param->cv; + + /* Unmask the input data */ + strm->avail_in += masked_avail_in; + masked_avail_in = 0; + + /* If we encounter an error, it means there is a bug in DFLTCC call */ + Assert(cc != DFLTCC_CC_OP2_CORRUPT || param->oesc == 0, "BUG"); + + /* Update Block-Continuation Flag. It will be used to check whether to call + * GDHT the next time. + */ + if (cc == DFLTCC_CC_OK) { + if (soft_bcc) { + send_eobs(strm, param); + param->bcf = 0; + dfltcc_state->block_threshold = + strm->total_in + dfltcc_state->block_size; + } else + param->bcf = 1; + if (flush == Z_FINISH) { + if (need_empty_block) + /* Make the current deflate() call also close the stream */ + return 0; + else { + bi_windup(state); + *result = finish_done; + } + } else { + if (flush == Z_FULL_FLUSH) + param->hl = 0; /* Clear history */ + *result = flush == Z_NO_FLUSH ? need_more : block_done; + } + } else { + param->bcf = 1; + *result = need_more; + } + if (strm->avail_in != 0 && strm->avail_out != 0) + goto again; /* deflate() must use all input or all output */ + return 1; +} +EXPORT_SYMBOL(dfltcc_deflate); |