diff options
Diffstat (limited to 'lib/zlib_dfltcc/dfltcc_inflate.c')
| -rw-r--r-- | lib/zlib_dfltcc/dfltcc_inflate.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/lib/zlib_dfltcc/dfltcc_inflate.c b/lib/zlib_dfltcc/dfltcc_inflate.c new file mode 100644 index 0000000000..437cd34c84 --- /dev/null +++ b/lib/zlib_dfltcc/dfltcc_inflate.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: Zlib + +#include "../zlib_inflate/inflate.h" +#include "dfltcc_util.h" +#include "dfltcc_inflate.h" +#include <asm/setup.h> +#include <linux/export.h> +#include <linux/zutil.h> + +/* + * Expand. + */ +int dfltcc_can_inflate( + z_streamp strm +) +{ + struct inflate_state *state = (struct inflate_state *)strm->state; + struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state); + + /* Check for kernel dfltcc command line parameter */ + if (zlib_dfltcc_support == ZLIB_DFLTCC_DISABLED || + zlib_dfltcc_support == ZLIB_DFLTCC_DEFLATE_ONLY) + return 0; + + /* Unsupported hardware */ + return is_bit_set(dfltcc_state->af.fns, DFLTCC_XPND) && + is_bit_set(dfltcc_state->af.fmts, DFLTCC_FMT0); +} +EXPORT_SYMBOL(dfltcc_can_inflate); + +void dfltcc_reset_inflate_state(z_streamp strm) { + struct inflate_state *state = (struct inflate_state *)strm->state; + struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state); + + dfltcc_reset_state(dfltcc_state); +} +EXPORT_SYMBOL(dfltcc_reset_inflate_state); + +static int dfltcc_was_inflate_used( + z_streamp strm +) +{ + struct inflate_state *state = (struct inflate_state *)strm->state; + struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param; + + return !param->nt; +} + +static int dfltcc_inflate_disable( + z_streamp strm +) +{ + struct inflate_state *state = (struct inflate_state *)strm->state; + struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state); + + if (!dfltcc_can_inflate(strm)) + return 0; + if (dfltcc_was_inflate_used(strm)) + /* DFLTCC has already decompressed some data. Since there is not + * enough information to resume decompression in software, the call + * must fail. + */ + return 1; + /* DFLTCC was not used yet - decompress in software */ + memset(&dfltcc_state->af, 0, sizeof(dfltcc_state->af)); + return 0; +} + +static dfltcc_cc dfltcc_xpnd( + z_streamp strm +) +{ + struct inflate_state *state = (struct inflate_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_XPND | HBT_CIRCULAR, + param, &strm->next_out, &avail_out, + &strm->next_in, &avail_in, state->window); + strm->avail_in = avail_in; + strm->avail_out = avail_out; + return cc; +} + +dfltcc_inflate_action dfltcc_inflate( + z_streamp strm, + int flush, + int *ret +) +{ + struct inflate_state *state = (struct inflate_state *)strm->state; + struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state); + struct dfltcc_param_v0 *param = &dfltcc_state->param; + dfltcc_cc cc; + + if (flush == Z_BLOCK || flush == Z_PACKET_FLUSH) { + /* DFLTCC does not support stopping on block boundaries (Z_BLOCK flush option) + * as well as the use of Z_PACKET_FLUSH option (used exclusively by PPP driver) + */ + if (dfltcc_inflate_disable(strm)) { + *ret = Z_STREAM_ERROR; + return DFLTCC_INFLATE_BREAK; + } else + return DFLTCC_INFLATE_SOFTWARE; + } + + if (state->last) { + if (state->bits != 0) { + strm->next_in++; + strm->avail_in--; + state->bits = 0; + } + state->mode = CHECK; + return DFLTCC_INFLATE_CONTINUE; + } + + if (strm->avail_in == 0 && !param->cf) + return DFLTCC_INFLATE_BREAK; + + if (!state->window || state->wsize == 0) { + state->mode = MEM; + return DFLTCC_INFLATE_CONTINUE; + } + + /* Translate stream to parameter block */ + param->cvt = CVT_ADLER32; + param->sbb = state->bits; + if (param->hl) + param->nt = 0; /* Honor history for the first block */ + param->cv = state->check; + + /* Inflate */ + do { + cc = dfltcc_xpnd(strm); + } while (cc == DFLTCC_CC_AGAIN); + + /* Translate parameter block to stream */ + strm->msg = oesc_msg(dfltcc_state->msg, param->oesc); + state->last = cc == DFLTCC_CC_OK; + state->bits = param->sbb; + state->check = param->cv; + if (cc == DFLTCC_CC_OP2_CORRUPT && param->oesc != 0) { + /* Report an error if stream is corrupted */ + state->mode = BAD; + return DFLTCC_INFLATE_CONTINUE; + } + state->mode = TYPEDO; + /* Break if operands are exhausted, otherwise continue looping */ + return (cc == DFLTCC_CC_OP1_TOO_SHORT || cc == DFLTCC_CC_OP2_TOO_SHORT) ? + DFLTCC_INFLATE_BREAK : DFLTCC_INFLATE_CONTINUE; +} +EXPORT_SYMBOL(dfltcc_inflate); |