}
#endif
-static __always_inline int page_is_fake_head(struct page *page)
+static __always_inline int page_is_fake_head(const struct page *page)
{
return page_fixed_fake_head(page) != page;
}
*/
#define folio_page(folio, n) nth_page(&(folio)->page, n)
-static __always_inline int PageTail(struct page *page)
+static __always_inline int PageTail(const struct page *page)
{
return READ_ONCE(page->compound_head) & 1 || page_is_fake_head(page);
}
-static __always_inline int PageCompound(struct page *page)
+static __always_inline int PageCompound(const struct page *page)
{
return test_bit(PG_head, &page->flags) ||
READ_ONCE(page->compound_head) & 1;
}
#endif
+static const unsigned long *const_folio_flags(const struct folio *folio,
+ unsigned n)
+{
+ const struct page *page = &folio->page;
+
+ VM_BUG_ON_PGFLAGS(PageTail(page), page);
+ VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page);
+ return &page[n].flags;
+}
+
static unsigned long *folio_flags(struct folio *folio, unsigned n)
{
struct page *page = &folio->page;
* Macros to create function definitions for page flags
*/
#define FOLIO_TEST_FLAG(name, page) \
-static __always_inline bool folio_test_##name(struct folio *folio) \
-{ return test_bit(PG_##name, folio_flags(folio, page)); }
+static __always_inline bool folio_test_##name(const struct folio *folio) \
+{ return test_bit(PG_##name, const_folio_flags(folio, page)); }
#define FOLIO_SET_FLAG(name, page) \
static __always_inline void folio_set_##name(struct folio *folio) \
#define TESTPAGEFLAG(uname, lname, policy) \
FOLIO_TEST_FLAG(lname, FOLIO_##policy) \
-static __always_inline int Page##uname(struct page *page) \
+static __always_inline int Page##uname(const struct page *page) \
{ return test_bit(PG_##lname, &policy(page, 0)->flags); }
#define SETPAGEFLAG(uname, lname, policy) \
return test_bit(PG_head, folio_flags(folio, FOLIO_PF_ANY));
}
-static __always_inline int PageHead(struct page *page)
+static __always_inline int PageHead(const struct page *page)
{
PF_POISONED_CHECK(page);
return test_bit(PG_head, &page->flags) && !page_is_fake_head(page);