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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->flags ? REVERSE(state->check) : 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 = state->flags ? REVERSE(param->cv) : 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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