lib/zlib: add zlib_deflate_dfltcc_enabled() function

Add a new function to zlib.h checking if s390 Deflate-Conversion
facility is installed and enabled.

Link: http://lkml.kernel.org/r/20200103223334.20669-6-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Eduard Shishkin <edward6@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/zlib_dfltcc/dfltcc_util.h

@@ -3,8 +3,6 @@
 #define DFLTCC_UTIL_H
 
 #include <linux/zutil.h>
-#include <asm/facility.h>
-#include <asm/setup.h>
 
 /*
  * C wrapper for the DEFLATE CONVERSION CALL instruction.
@@ -24,7 +22,6 @@ typedef enum {
 #define HBT_CIRCULAR (1 << 7)
 #define HB_BITS 15
 #define HB_SIZE (1 << HB_BITS)
-#define DFLTCC_FACILITY 151
 
 static inline dfltcc_cc dfltcc(
     int fn,
@@ -101,12 +98,6 @@ static inline int dfltcc_are_params_ok(
         (strategy == Z_DEFAULT_STRATEGY);
 }
 
-static inline int is_dfltcc_enabled(void)
-{
-    return (zlib_dfltcc_support != ZLIB_DFLTCC_DISABLED &&
-            test_facility(DFLTCC_FACILITY));
-}
-
 char *oesc_msg(char *buf, int oesc);
 
 #endif /* DFLTCC_UTIL_H */