[PATCH 6.1.y] selftests/mm: Move default_huge_page_size to vm_util.c

[Leon Hwang <leon.hwang@linux.dev>]

Fix the build error:

map_hugetlb.c: In function 'main':
map_hugetlb.c:79:25: warning: implicit declaration of function 'default_huge_page_size' [-Wimplicit-function-declaration]
   79 |         hugepage_size = default_huge_page_size();
      |                         ^~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccYOogvJ.o: in function 'main':
map_hugetlb.c:(.text+0x114): undefined reference to 'default_huge_page_size'

According to the latest selftests, 'default_huge_page_size' has been
moved to 'vm_util.c'. So fix the error by the same way.

Reviewed-by: Lance Yang <lance.yang@linux.dev>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
---
 tools/testing/selftests/vm/Makefile      |  1 +
 tools/testing/selftests/vm/userfaultfd.c | 24 ------------------------
 tools/testing/selftests/vm/vm_util.c     | 21 +++++++++++++++++++++
 tools/testing/selftests/vm/vm_util.h     |  1 +
 4 files changed, 23 insertions(+), 24 deletions(-)

diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
index 192ea3725c5c..ed90deebef0d 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -100,6 +100,7 @@ $(OUTPUT)/madv_populate: vm_util.c
 $(OUTPUT)/soft-dirty: vm_util.c
 $(OUTPUT)/split_huge_page_test: vm_util.c
 $(OUTPUT)/userfaultfd: vm_util.c
+$(OUTPUT)/map_hugetlb: vm_util.c
 
 ifeq ($(MACHINE),x86_64)
 BINARIES_32 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_32))
diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 297f250c1d95..4751b28eba18 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -1674,30 +1674,6 @@ static int userfaultfd_stress(void)
 		|| userfaultfd_events_test() || userfaultfd_minor_test();
 }
 
-/*
- * Copied from mlock2-tests.c
- */
-unsigned long default_huge_page_size(void)
-{
-	unsigned long hps = 0;
-	char *line = NULL;
-	size_t linelen = 0;
-	FILE *f = fopen("/proc/meminfo", "r");
-
-	if (!f)
-		return 0;
-	while (getline(&line, &linelen, f) > 0) {
-		if (sscanf(line, "Hugepagesize:       %lu kB", &hps) == 1) {
-			hps <<= 10;
-			break;
-		}
-	}
-
-	free(line);
-	fclose(f);
-	return hps;
-}
-
 static void set_test_type(const char *type)
 {
 	if (!strcmp(type, "anon")) {
diff --git a/tools/testing/selftests/vm/vm_util.c b/tools/testing/selftests/vm/vm_util.c
index fc5743bc1283..613cc61602c9 100644
--- a/tools/testing/selftests/vm/vm_util.c
+++ b/tools/testing/selftests/vm/vm_util.c
@@ -161,6 +161,27 @@ bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size)
 	return __check_huge(addr, "ShmemPmdMapped:", nr_hpages, hpage_size);
 }
 
+unsigned long default_huge_page_size(void)
+{
+	unsigned long hps = 0;
+	char *line = NULL;
+	size_t linelen = 0;
+	FILE *f = fopen("/proc/meminfo", "r");
+
+	if (!f)
+		return 0;
+	while (getline(&line, &linelen, f) > 0) {
+		if (sscanf(line, "Hugepagesize:       %lu kB", &hps) == 1) {
+			hps <<= 10;
+			break;
+		}
+	}
+
+	free(line);
+	fclose(f);
+	return hps;
+}
+
 static bool check_vmflag(void *addr, const char *flag)
 {
 	char buffer[MAX_LINE_LENGTH];
diff --git a/tools/testing/selftests/vm/vm_util.h b/tools/testing/selftests/vm/vm_util.h
index 470f85fe9594..a4439db0d6f8 100644
--- a/tools/testing/selftests/vm/vm_util.h
+++ b/tools/testing/selftests/vm/vm_util.h
@@ -11,4 +11,5 @@ uint64_t read_pmd_pagesize(void);
 bool check_huge_anon(void *addr, int nr_hpages, uint64_t hpage_size);
 bool check_huge_file(void *addr, int nr_hpages, uint64_t hpage_size);
 bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size);
+unsigned long default_huge_page_size(void);
 bool softdirty_supported(void);
-- 
2.43.0