From: Mike Rapoport <rppt@xxxxxxxxxx>
Subject: selftest/vm: add helpers to detect PAGE_SIZE and PAGE_SHIFT
PAGE_SIZE is not 4096 in many configurations, particularly ppc64 uses 64K
pages in majority of cases.
Add helpers to detect PAGE_SIZE and PAGE_SHIFT dynamically.
Without this tests are broken w.r.t reading /proc/self/pagemap
if (pread(pagemap_fd, ent, sizeof(ent),
(uintptr_t)ptr >> (PAGE_SHIFT - 3)) != sizeof(ent))
err(2, "read pagemap");
Link: https://lkml.kernel.org/r/20220307054355.149820-2-aneesh.kumar@xxxxxxxxxxxxx
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/vm/gup_test.c | 3 +-
tools/testing/selftests/vm/util.h | 27 +++++++++++++++++++++---
2 files changed, 26 insertions(+), 4 deletions(-)
--- a/tools/testing/selftests/vm/gup_test.c~selftest-vm-add-helpers-to-detect-page_size-and-page_shift
+++ a/tools/testing/selftests/vm/gup_test.c
@@ -10,8 +10,9 @@
#include <assert.h>
#include "../../../../mm/gup_test.h"
+#include "util.h"
+
#define MB (1UL << 20)
-#define PAGE_SIZE sysconf(_SC_PAGESIZE)
/* Just the flags we need, copied from mm.h: */
#define FOLL_WRITE 0x01 /* check pte is writable */
--- a/tools/testing/selftests/vm/util.h~selftest-vm-add-helpers-to-detect-page_size-and-page_shift
+++ a/tools/testing/selftests/vm/util.h
@@ -6,11 +6,32 @@
#include <stdint.h>
#include <sys/mman.h>
#include <err.h>
+#include <string.h> /* ffsl() */
+#include <unistd.h> /* _SC_PAGESIZE */
-#define PAGE_SHIFT 12
-#define HPAGE_SHIFT 21
+static unsigned int __page_size;
+static unsigned int __page_shift;
-#define PAGE_SIZE (1 << PAGE_SHIFT)
+static inline unsigned int page_size(void)
+{
+ if (!__page_size)
+ __page_size = sysconf(_SC_PAGESIZE);
+ return __page_size;
+}
+
+static inline unsigned int page_shift(void)
+{
+ if (!__page_shift)
+ __page_shift = (ffsl(page_size()) - 1);
+ return __page_shift;
+}
+
+#define PAGE_SHIFT (page_shift())
+#define PAGE_SIZE (page_size())
+/*
+ * On ppc64 this will only work with radix 2M hugepage size
+ */
+#define HPAGE_SHIFT 21
#define HPAGE_SIZE (1 << HPAGE_SHIFT)
#define PAGEMAP_PRESENT(ent) (((ent) & (1ull << 63)) != 0)
_
