linux-stable/include/linux/secretmem.h
Matthew Wilcox (Oracle) 8f9ff2deb8 secretmem: convert page_is_secretmem() to folio_is_secretmem()
The only caller already has a folio, so use it to save calling
compound_head() in PageLRU() and remove a use of page->mapping.

Link: https://lkml.kernel.org/r/20230822202335.179081-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-24 16:20:31 -07:00

53 lines
1.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _LINUX_SECRETMEM_H
#define _LINUX_SECRETMEM_H
#ifdef CONFIG_SECRETMEM
extern const struct address_space_operations secretmem_aops;
static inline bool folio_is_secretmem(struct folio *folio)
{
struct address_space *mapping;
/*
* Using folio_mapping() is quite slow because of the actual call
* instruction.
* We know that secretmem pages are not compound and LRU so we can
* save a couple of cycles here.
*/
if (folio_test_large(folio) || !folio_test_lru(folio))
return false;
mapping = (struct address_space *)
((unsigned long)folio->mapping & ~PAGE_MAPPING_FLAGS);
if (!mapping || mapping != folio->mapping)
return false;
return mapping->a_ops == &secretmem_aops;
}
bool vma_is_secretmem(struct vm_area_struct *vma);
bool secretmem_active(void);
#else
static inline bool vma_is_secretmem(struct vm_area_struct *vma)
{
return false;
}
static inline bool folio_is_secretmem(struct folio *folio)
{
return false;
}
static inline bool secretmem_active(void)
{
return false;
}
#endif /* CONFIG_SECRETMEM */
#endif /* _LINUX_SECRETMEM_H */