summaryrefslogtreecommitdiff
path: root/lib/zlib_dfltcc
diff options
context:
space:
mode:
authorMikhail Zaslonko <zaslonko@linux.ibm.com>2023-01-26 14:14:22 +0100
committerAndrew Morton <akpm@linux-foundation.org>2023-02-02 22:50:08 -0800
commit9a549338260ac6eaa495095d4c237aee09aa5a99 (patch)
tree54bd03daeeabc36ca328183de442e19082b11f51 /lib/zlib_dfltcc
parent4cc06c9afbb4dbed007f06450127ab745d6dc450 (diff)
lib/zlib: implement switching between DFLTCC and software
This commit is based on: https://github.com/zlib-ng/zlib-ng/commit/fc04275 Link: https://lkml.kernel.org/r/20230126131428.1222214-3-zaslonko@linux.ibm.com Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib/zlib_dfltcc')
-rw-r--r--lib/zlib_dfltcc/dfltcc_deflate.c38
1 files changed, 22 insertions, 16 deletions
diff --git a/lib/zlib_dfltcc/dfltcc_deflate.c b/lib/zlib_dfltcc/dfltcc_deflate.c
index 6c946e8532ee..dc85ec890163 100644
--- a/lib/zlib_dfltcc/dfltcc_deflate.c
+++ b/lib/zlib_dfltcc/dfltcc_deflate.c
@@ -112,30 +112,36 @@ int dfltcc_deflate(
int soft_bcc;
int no_flush;
- if (!dfltcc_can_deflate(strm))
+ if (!dfltcc_can_deflate(strm)) {
+ /* Clear history. */
+ if (flush == Z_FULL_FLUSH)
+ param->hl = 0;
return 0;
+ }
again:
masked_avail_in = 0;
soft_bcc = 0;
no_flush = flush == Z_NO_FLUSH;
- /* Trailing empty block. Switch to software, except when Continuation Flag
- * is set, which means that DFLTCC has buffered some output in the
- * parameter block and needs to be called again in order to flush it.
+ /* No input data. Return, except when Continuation Flag is set, which means
+ * that DFLTCC has buffered some output in the parameter block and needs to
+ * be called again in order to flush it.
*/
- if (flush == Z_FINISH && strm->avail_in == 0 && !param->cf) {
- if (param->bcf) {
- /* A block is still open, and the hardware does not support closing
- * blocks without adding data. Thus, close it manually.
- */
+ if (strm->avail_in == 0 && !param->cf) {
+ /* A block is still open, and the hardware does not support closing
+ * blocks without adding data. Thus, close it manually.
+ */
+ if (!no_flush && param->bcf) {
send_eobs(strm, param);
param->bcf = 0;
}
- return 0;
- }
-
- if (strm->avail_in == 0 && !param->cf) {
+ /* Let one of deflate_* functions write a trailing empty block. */
+ if (flush == Z_FINISH)
+ return 0;
+ /* Clear history. */
+ if (flush == Z_FULL_FLUSH)
+ param->hl = 0;
*result = need_more;
return 1;
}
@@ -189,7 +195,7 @@ again:
param->cvt = CVT_ADLER32;
if (!no_flush)
/* We need to close a block. Always do this in software - when there is
- * no input data, the hardware will not nohor BCC. */
+ * no input data, the hardware will not hohor BCC. */
soft_bcc = 1;
if (flush == Z_FINISH && !param->bcf)
/* We are about to open a BFINAL block, set Block Header Final bit
@@ -204,8 +210,8 @@ again:
param->sbb = (unsigned int)state->bi_valid;
if (param->sbb > 0)
*strm->next_out = (Byte)state->bi_buf;
- if (param->hl)
- param->nt = 0; /* Honor history */
+ /* Honor history and check value */
+ param->nt = 0;
param->cv = strm->adler;
/* When opening a block, choose a Huffman-Table Type */