[PATCH v5 bpf-next 4/5] vmalloc: introduce huge_vmalloc_supported

[Song Liu]

huge_vmalloc_supported() exposes vmap_allow_huge so that users of vmalloc
APIs could know whether vmalloc will return huge pages.

Suggested-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Signed-off-by: Song Liu <song@xxxxxxxxxx>
---
 include/linux/vmalloc.h | 6 ++++++
 mm/vmalloc.c            | 5 +++++
 2 files changed, 11 insertions(+)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 59d3e1f3e108..aa2182959fc5 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -243,11 +243,17 @@ static inline void set_vm_flush_reset_perms(void *addr)
 	if (vm)
 		vm->flags |= VM_FLUSH_RESET_PERMS;
 }
+bool huge_vmalloc_supported(void);
 
 #else
 static inline void set_vm_flush_reset_perms(void *addr)
 {
 }
+
+static inline bool huge_vmalloc_supported(void)
+{
+	return false;
+}
 #endif
 
 /* for /proc/kcore */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index effd1ff6a4b4..0a5add4b5b2d 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -72,6 +72,11 @@ early_param("nohugevmalloc", set_nohugevmalloc);
 static const bool vmap_allow_huge = false;
 #endif	/* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
 
+bool huge_vmalloc_supported(void)
+{
+	return vmap_allow_huge;
+}
+
 bool is_vmalloc_addr(const void *x)
 {
 	unsigned long addr = (unsigned long)kasan_reset_tag(x);
-- 
2.30.2