zcache: Use div_u64 for 64-bit division

xv_get_total_size_bytes returns a u64 value and it's used in a division.
This causes build failures in 32-bit architectures, as reported by Randy
Dunlap.

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index 66469ac..2c41c44 100644 (file)
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -28,6 +28,7 @@
 #include <linux/spinlock.h>
 #include <linux/types.h>
 #include <linux/atomic.h>
+#include <linux/math64.h>
 #include "tmem.h"
 
 #include "../zram/xvmalloc.h" /* if built in drivers/staging */
@@ -1162,6 +1163,7 @@ static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph,
        uint16_t client_id = get_client_id_from_client(cli);
        unsigned long zv_mean_zsize;
        unsigned long curr_pers_pampd_count;
+       u64 total_zsize;
 
        if (eph) {
                ret = zcache_compress(page, &cdata, &clen);
@@ -1194,8 +1196,9 @@ static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph,
                }
                /* reject if mean compression is too poor */
                if ((clen > zv_max_mean_zsize) && (curr_pers_pampd_count > 0)) {
-                       zv_mean_zsize = xv_get_total_size_bytes(cli->xvpool) /
-                                               curr_pers_pampd_count;
+                       total_zsize = xv_get_total_size_bytes(cli->xvpool);
+                       zv_mean_zsize = div_u64(total_zsize,
+                                               curr_pers_pampd_count);
                        if (zv_mean_zsize > zv_max_mean_zsize) {
                                zcache_mean_compress_poor++;
                                goto out;