+// SPDX-License-Identifier: Zlib
+
+#include "../zlib_inflate/inflate.h"
+#include "dfltcc_util.h"
+#include "dfltcc.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);
+
+ /* 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);
+}
+
+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;
+}
projects / linux-2.6-microblaze.git / commitdiff