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selftest/vm: add helpers to detect PAGE_SIZE and PAGE_SHIFT

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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@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mike Rapoport 2022-03-24 18:09:46 -07:00 committed by Linus Torvalds
parent 90647d9d72
commit 6f6a841fb7
2 changed files with 26 additions and 4 deletions
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3
tools/testing/selftests/vm/gup_test.c
View File

@ -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 */

27
tools/testing/selftests/vm/util.h
View File

@ -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
static unsigned int __page_size;
static unsigned int __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 PAGE_SIZE (1 << PAGE_SHIFT)
#define HPAGE_SIZE (1 << HPAGE_SHIFT)
#define PAGEMAP_PRESENT(ent) (((ent) & (1ull << 63)) != 0)