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- // SPDX-License-Identifier: Zlib
- #include "../zlib_inflate/inflate.h"
- #include "dfltcc_util.h"
- #include "dfltcc.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 compression settings */
- if (state->wbits != HB_BITS)
- 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);
- 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) {
- /* DFLTCC does not support stopping on block boundaries */
- 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;
- param->hl = state->whave; /* Software and hardware history formats match */
- param->ho = (state->write - state->whave) & ((1 << HB_BITS) - 1);
- 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->whave = param->hl;
- state->write = (param->ho + param->hl) & ((1 << HB_BITS) - 1);
- 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);
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