linuxdebug/tools/testing/selftests/vm/util.h

70 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __KSELFTEST_VM_UTIL_H
#define __KSELFTEST_VM_UTIL_H
#include <stdint.h>
#include <sys/mman.h>
#include <err.h>
#include <string.h> /* ffsl() */
#include <unistd.h> /* _SC_PAGESIZE */
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 HPAGE_SIZE (1 << HPAGE_SHIFT)
#define PAGEMAP_PRESENT(ent) (((ent) & (1ull << 63)) != 0)
#define PAGEMAP_PFN(ent) ((ent) & ((1ull << 55) - 1))
static inline int64_t allocate_transhuge(void *ptr, int pagemap_fd)
{
uint64_t ent[2];
/* drop pmd */
if (mmap(ptr, HPAGE_SIZE, PROT_READ | PROT_WRITE,
MAP_FIXED | MAP_ANONYMOUS |
MAP_NORESERVE | MAP_PRIVATE, -1, 0) != ptr)
errx(2, "mmap transhuge");
if (madvise(ptr, HPAGE_SIZE, MADV_HUGEPAGE))
err(2, "MADV_HUGEPAGE");
/* allocate transparent huge page */
*(volatile void **)ptr = ptr;
if (pread(pagemap_fd, ent, sizeof(ent),
(uintptr_t)ptr >> (PAGE_SHIFT - 3)) != sizeof(ent))
err(2, "read pagemap");
if (PAGEMAP_PRESENT(ent[0]) && PAGEMAP_PRESENT(ent[1]) &&
PAGEMAP_PFN(ent[0]) + 1 == PAGEMAP_PFN(ent[1]) &&
!(PAGEMAP_PFN(ent[0]) & ((1 << (HPAGE_SHIFT - PAGE_SHIFT)) - 1)))
return PAGEMAP_PFN(ent[0]);
return -1;
}
#endif