mm/hugetlb: remove prepare_hugepage_range()

Only mips and loongarch implemented this API, however what it does was
checking against stack overflow for either len or addr.  That's already
done in arch's arch_get_unmapped_area*() functions, even though it may not
be 100% identical checks.

For example, for both of the architectures, there will be a trivial
difference on how stack top was defined.  The old code uses STACK_TOP
which may be slightly smaller than TASK_SIZE on either of them, but the
hope is that shouldn't be a problem.

It means the whole API is pretty much obsolete at least now, remove it
completely.

Link: https://lkml.kernel.org/r/20250627160707.2124580-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

2 files changed, 0 insertions, 14 deletions

diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
index 3e0a8fe9b108..4bce4f07f44f 100644
--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h
@@ -114,14 +114,6 @@ static inline int huge_pte_none_mostly(pte_t pte)
 }
 #endif
 
-#ifndef __HAVE_ARCH_PREPARE_HUGEPAGE_RANGE
-static inline int prepare_hugepage_range(struct file *file,
-		unsigned long addr, unsigned long len)
-{
-	return 0;
-}
-#endif
-
 #ifndef __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
 static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
 		unsigned long addr, pte_t *ptep)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index c6c87eae4a8d..474de8e2a8f2 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -359,12 +359,6 @@ static inline void hugetlb_show_meminfo_node(int nid)
 {
 }
 
-static inline int prepare_hugepage_range(struct file *file,
-				unsigned long addr, unsigned long len)
-{
-	return -EINVAL;
-}
-
 static inline void hugetlb_vma_lock_read(struct vm_area_struct *vma)
 {
 }