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1// SPDX-License-Identifier: Zlib2 3#include "../zlib_inflate/inflate.h"4#include "dfltcc_util.h"5#include "dfltcc_inflate.h"6#include <asm/setup.h>7#include <linux/export.h>8#include <linux/zutil.h>9 10/*11 * Expand.12 */13int dfltcc_can_inflate(14 z_streamp strm15)16{17 struct inflate_state *state = (struct inflate_state *)strm->state;18 struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);19 20 /* Check for kernel dfltcc command line parameter */21 if (zlib_dfltcc_support == ZLIB_DFLTCC_DISABLED ||22 zlib_dfltcc_support == ZLIB_DFLTCC_DEFLATE_ONLY)23 return 0;24 25 /* Unsupported hardware */26 return is_bit_set(dfltcc_state->af.fns, DFLTCC_XPND) &&27 is_bit_set(dfltcc_state->af.fmts, DFLTCC_FMT0);28}29EXPORT_SYMBOL(dfltcc_can_inflate);30 31void dfltcc_reset_inflate_state(z_streamp strm) {32 struct inflate_state *state = (struct inflate_state *)strm->state;33 struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);34 35 dfltcc_reset_state(dfltcc_state);36}37EXPORT_SYMBOL(dfltcc_reset_inflate_state);38 39static int dfltcc_was_inflate_used(40 z_streamp strm41)42{43 struct inflate_state *state = (struct inflate_state *)strm->state;44 struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param;45 46 return !param->nt;47}48 49static int dfltcc_inflate_disable(50 z_streamp strm51)52{53 struct inflate_state *state = (struct inflate_state *)strm->state;54 struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);55 56 if (!dfltcc_can_inflate(strm))57 return 0;58 if (dfltcc_was_inflate_used(strm))59 /* DFLTCC has already decompressed some data. Since there is not60 * enough information to resume decompression in software, the call61 * must fail.62 */63 return 1;64 /* DFLTCC was not used yet - decompress in software */65 memset(&dfltcc_state->af, 0, sizeof(dfltcc_state->af));66 return 0;67}68 69static dfltcc_cc dfltcc_xpnd(70 z_streamp strm71)72{73 struct inflate_state *state = (struct inflate_state *)strm->state;74 struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param;75 size_t avail_in = strm->avail_in;76 size_t avail_out = strm->avail_out;77 dfltcc_cc cc;78 79 cc = dfltcc(DFLTCC_XPND | HBT_CIRCULAR,80 param, &strm->next_out, &avail_out,81 &strm->next_in, &avail_in, state->window);82 strm->avail_in = avail_in;83 strm->avail_out = avail_out;84 return cc;85}86 87dfltcc_inflate_action dfltcc_inflate(88 z_streamp strm,89 int flush,90 int *ret91)92{93 struct inflate_state *state = (struct inflate_state *)strm->state;94 struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);95 struct dfltcc_param_v0 *param = &dfltcc_state->param;96 dfltcc_cc cc;97 98 if (flush == Z_BLOCK || flush == Z_PACKET_FLUSH) {99 /* DFLTCC does not support stopping on block boundaries (Z_BLOCK flush option)100 * as well as the use of Z_PACKET_FLUSH option (used exclusively by PPP driver)101 */102 if (dfltcc_inflate_disable(strm)) {103 *ret = Z_STREAM_ERROR;104 return DFLTCC_INFLATE_BREAK;105 } else106 return DFLTCC_INFLATE_SOFTWARE;107 }108 109 if (state->last) {110 if (state->bits != 0) {111 strm->next_in++;112 strm->avail_in--;113 state->bits = 0;114 }115 state->mode = CHECK;116 return DFLTCC_INFLATE_CONTINUE;117 }118 119 if (strm->avail_in == 0 && !param->cf)120 return DFLTCC_INFLATE_BREAK;121 122 if (!state->window || state->wsize == 0) {123 state->mode = MEM;124 return DFLTCC_INFLATE_CONTINUE;125 }126 127 /* Translate stream to parameter block */128 param->cvt = CVT_ADLER32;129 param->sbb = state->bits;130 if (param->hl)131 param->nt = 0; /* Honor history for the first block */132 param->cv = state->check;133 134 /* Inflate */135 do {136 cc = dfltcc_xpnd(strm);137 } while (cc == DFLTCC_CC_AGAIN);138 139 /* Translate parameter block to stream */140 strm->msg = oesc_msg(dfltcc_state->msg, param->oesc);141 state->last = cc == DFLTCC_CC_OK;142 state->bits = param->sbb;143 state->check = param->cv;144 if (cc == DFLTCC_CC_OP2_CORRUPT && param->oesc != 0) {145 /* Report an error if stream is corrupted */146 state->mode = BAD;147 return DFLTCC_INFLATE_CONTINUE;148 }149 state->mode = TYPEDO;150 /* Break if operands are exhausted, otherwise continue looping */151 return (cc == DFLTCC_CC_OP1_TOO_SHORT || cc == DFLTCC_CC_OP2_TOO_SHORT) ?152 DFLTCC_INFLATE_BREAK : DFLTCC_INFLATE_CONTINUE;153}154EXPORT_SYMBOL(dfltcc_inflate);155