summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/mm/util.h
diff options
context:
space:
mode:
Diffstat (limited to 'tools/testing/selftests/mm/util.h')
-rw-r--r--tools/testing/selftests/mm/util.h69
1 files changed, 69 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/util.h b/tools/testing/selftests/mm/util.h
new file mode 100644
index 000000000000..b27d26199334
--- /dev/null
+++ b/tools/testing/selftests/mm/util.h
@@ -0,0 +1,69 @@
+/* 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