From 772ddd6500a74220e641782cc2ee892433197192 Mon Sep 17 00:00:00 2001

From: IBM developers

Date: Mon, 25 May 2020 14:09:48 +0200

Subject: [PATCH] Fix for Z hardware-accelerated deflate for s390x

 architectures

---

 configure                     |  7 +++

 contrib/s390/dfltcc.c         | 94 ++++++++++++++++++++---------------

 contrib/s390/dfltcc_deflate.h | 10 ++--

 deflate.c                     | 12 +++--

 4 files changed, 76 insertions(+), 47 deletions(-)

diff --git a/configure b/configure

index 66caece..bfe4386 100755

--- a/configure

+++ b/configure

@@ -114,6 +114,7 @@ case "$1" in

       echo '  configure [--const] [--zprefix] [--prefix=PREFIX]  [--eprefix=EXPREFIX]' | tee -a configure.log

       echo '    [--static] [--64] [--libdir=LIBDIR] [--sharedlibdir=LIBDIR]' | tee -a configure.log

       echo '    [--includedir=INCLUDEDIR] [--archs="-arch i386 -arch x86_64"]' | tee -a configure.log

+      echo '    [--dfltcc]' | tee -a configure.log

         exit 0 ;;

     -p*=* | --prefix=*) prefix=`echo $1 | sed 's/.*=//'`; shift ;;

     -e*=* | --eprefix=*) exec_prefix=`echo $1 | sed 's/.*=//'`; shift ;;

@@ -137,6 +138,12 @@ case "$1" in

     -c* | --const) zconst=1; shift ;;

     -w* | --warn) warn=1; shift ;;

     -d* | --debug) debug=1; shift ;;

+    --dfltcc)

+	    CFLAGS="$CFLAGS -DDFLTCC"

+      OBJC="$OBJC dfltcc.o"

+	    PIC_OBJC="$PIC_OBJC dfltcc.lo"

+      shift

+      ;; 

     *)

       echo "unknown option: $1" | tee -a configure.log

       echo "$0 --help for help" | tee -a configure.log

diff --git a/contrib/s390/dfltcc.c b/contrib/s390/dfltcc.c

index d187796..face8f1 100644

--- a/contrib/s390/dfltcc.c

+++ b/contrib/s390/dfltcc.c

@@ -2,8 +2,8 @@

 /*

    Use the following commands to build zlib with DFLTCC support:

-        $ CFLAGS=-DDFLTCC ./configure

-        $ make OBJA=dfltcc.o PIC_OBJA=dfltcc.lo

+        $ ./configure --dfltcc

+        $ make 

 */

 #define _GNU_SOURCE

@@ -230,31 +230,28 @@ struct dfltcc_state {

 /*

    Compress.

  */

-local inline int dfltcc_are_params_ok(int level,

-                                      uInt window_bits,

-                                      int strategy,

-                                      uLong level_mask);

-local inline int dfltcc_are_params_ok(level, window_bits, strategy, level_mask)

+local inline int dfltcc_can_deflate_with_params(z_streamp strm,

+                                                 int level,

+                                                 uInt window_bits,

+                                                 int strategy);

+local inline int dfltcc_can_deflate_with_params(strm,

+                                                 level,

+                                                 window_bits,

+                                                 strategy)

+    z_streamp strm; 

     int level;

     uInt window_bits;

     int strategy;

-    uLong level_mask;

-{

-    return (level_mask & (1 << level)) != 0 &&

-        (window_bits == HB_BITS) &&

-        (strategy == Z_FIXED || strategy == Z_DEFAULT_STRATEGY);

-}

-

-

-int ZLIB_INTERNAL dfltcc_can_deflate(strm)

-    z_streamp strm;

 {

     deflate_state FAR *state = (deflate_state FAR *)strm->state;

     struct dfltcc_state FAR *dfltcc_state = GET_DFLTCC_STATE(state);

     /* Unsupported compression settings */

-    if (!dfltcc_are_params_ok(state->level, state->w_bits, state->strategy,

-                              dfltcc_state->level_mask))

+    if ((dfltcc_state->level_mask & (1 << level)) == 0)

+        return 0;

+    if (window_bits != HB_BITS)

+        return 0;

+    if (strategy != Z_FIXED && strategy != Z_DEFAULT_STRATEGY) 

         return 0;

     /* Unsupported hardware */

@@ -266,6 +263,17 @@ int ZLIB_INTERNAL dfltcc_can_deflate(strm)

     return 1;

 }

+int ZLIB_INTERNAL dfltcc_can_deflate(strm)

+    z_streamp strm;

+{

+    deflate_state FAR *state = (deflate_state FAR *)strm->state;

+

+    return dfltcc_can_deflate_with_params(strm,

+                                          state->level,

+                                          state->w_bits,

+                                          state->strategy);

+} 

+

 local void dfltcc_gdht OF((z_streamp strm));

 local void dfltcc_gdht(strm)

     z_streamp strm;

@@ -349,22 +357,24 @@ again:

     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;

     }

@@ -418,7 +428,7 @@ again:

     param->cvt = state->wrap == 2 ? CVT_CRC32 : 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 honor BCC. */

         soft_bcc = 1;

     if (flush == Z_FINISH && !param->bcf)

         /* We are about to open a BFINAL block, set Block Header Final bit

@@ -433,8 +443,8 @@ again:

     param->sbb = (unsigned int)state->bi_valid;

     if (param->sbb > 0)

         *strm->next_out = (Bytef)state->bi_buf;

-    if (param->hl)

-        param->nt = 0; /* Honor history */

+    /* Honor history and check value */

+    param->nt = 0; 

     param->cv = state->wrap == 2 ? ZSWAP32(strm->adler) : strm->adler;

     /* When opening a block, choose a Huffman-Table Type */

@@ -792,17 +802,20 @@ void ZLIB_INTERNAL dfltcc_free_window(strm, w)

    fly with deflateParams, we need to convert between hardware and software

    window formats.

 */

-int ZLIB_INTERNAL dfltcc_deflate_params(strm, level, strategy)

+int ZLIB_INTERNAL dfltcc_deflate_params(strm, level, strategy, flush)

     z_streamp strm;

     int level;

     int strategy;

+    int *flush;

 {

     deflate_state FAR *state = (deflate_state FAR *)strm->state;

     struct dfltcc_state FAR *dfltcc_state = GET_DFLTCC_STATE(state);

     struct dfltcc_param_v0 FAR *param = &dfltcc_state->param;

     int could_deflate = dfltcc_can_deflate(strm);

-    int can_deflate = dfltcc_are_params_ok(level, state->w_bits, strategy,

-                                           dfltcc_state->level_mask);

+    int can_deflate = dfltcc_can_deflate_with_params(strm,

+                                                     level,

+                                                     state->w_bits,

+                                                     strategy); 

     if (can_deflate == could_deflate)

         /* We continue to work in the same mode - no changes needed */

@@ -812,8 +825,11 @@ int ZLIB_INTERNAL dfltcc_deflate_params(strm, level, strategy)

         /* DFLTCC was not used yet - no changes needed */

         return Z_OK;

-    /* Switching between hardware and software is not implemented */

-    return Z_STREAM_ERROR;

+    /* For now, do not convert between window formats - simply get rid of the

+     * old data instead.

+     */

+    *flush = Z_FULL_FLUSH;

+    return Z_OK; 

 }

 /*

diff --git a/contrib/s390/dfltcc_deflate.h b/contrib/s390/dfltcc_deflate.h

index a129a91..947b1e4 100644

--- a/contrib/s390/dfltcc_deflate.h

+++ b/contrib/s390/dfltcc_deflate.h

@@ -9,7 +9,8 @@ int ZLIB_INTERNAL dfltcc_deflate OF((z_streamp strm,

                                      block_state *result));

 int ZLIB_INTERNAL dfltcc_deflate_params OF((z_streamp strm,

                                             int level,

-                                            int strategy));

+                                            int strategy,

+                                            int *flush)); 

 int ZLIB_INTERNAL dfltcc_deflate_set_dictionary OF((z_streamp strm,

                                                     const Bytef *dictionary,

                                                     uInt dict_length));

@@ -29,11 +30,14 @@ int ZLIB_INTERNAL dfltcc_deflate_get_dictionary OF((z_streamp strm,

     } while (0)

 #define DEFLATE_RESET_KEEP_HOOK(strm) \

     dfltcc_reset((strm), sizeof(deflate_state))

-#define DEFLATE_PARAMS_HOOK(strm, level, strategy) \

+#define DEFLATE_PARAMS_HOOK(strm, level, strategy, hook_flush) \

     do { \

         int err; \

 \

-        err = dfltcc_deflate_params((strm), (level), (strategy)); \

+        err = dfltcc_deflate_params((strm), \

+                                    (level), \

+                                    (strategy), \

+                                    (hook_flush)); \ 

         if (err == Z_STREAM_ERROR) \

             return err; \

     } while (0)

diff --git a/deflate.c b/deflate.c

index 9b09718..9284483 100644

--- a/deflate.c

+++ b/deflate.c

@@ -74,7 +74,7 @@ const char deflate_copyright[] =

 #define DEFLATE_SET_DICTIONARY_HOOK(strm, dict, dict_len) do {} while (0)

 #define DEFLATE_GET_DICTIONARY_HOOK(strm, dict, dict_len) do {} while (0)

 #define DEFLATE_RESET_KEEP_HOOK(strm) do {} while (0)

-#define DEFLATE_PARAMS_HOOK(strm, level, strategy) do {} while (0)

+#define DEFLATE_PARAMS_HOOK(strm, level, strategy, hook_flush) do {} while (0)

 #define DEFLATE_BOUND_ADJUST_COMPLEN(strm, complen, sourceLen) do {} while (0)

 #define DEFLATE_NEED_CONSERVATIVE_BOUND(strm) 0

 #define DEFLATE_HOOK(strm, flush, bstate) 0

@@ -589,6 +589,7 @@ int ZEXPORT deflateParams(strm, level, strategy)

 {

     deflate_state *s;

     compress_func func;

+    int hook_flush = Z_NO_FLUSH;

     if (deflateStateCheck(strm)) return Z_STREAM_ERROR;

     s = strm->state;

@@ -601,13 +602,14 @@ int ZEXPORT deflateParams(strm, level, strategy)

     if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {

         return Z_STREAM_ERROR;

     }

-    DEFLATE_PARAMS_HOOK(strm, level, strategy);

+    DEFLATE_PARAMS_HOOK(strm, level, strategy, &hook_flush);

     func = configuration_table[s->level].func;

-    if ((strategy != s->strategy || func != configuration_table[level].func) &&

-        s->high_water) {

+    if ((strategy != s->strategy || func != configuration_table[level].func ||

+        hook_flush != Z_NO_FLUSH) && s->high_water) {

         /* Flush the last buffer: */

-        int err = deflate(strm, Z_BLOCK);

+        int err = deflate(strm, RANK(hook_flush) > RANK(Z_BLOCK) ?

+                          hook_flush : Z_BLOCK); 

         if (err == Z_STREAM_ERROR)

             return err;

         if (strm->avail_out == 0)

-- 

2.24.1