On Tue, Sep 09, 2025 at 10:37:48PM +0300, Leon Romanovsky wrote:

quoted

On Tue, Sep 09, 2025 at 04:27:31PM +0300, Leon Romanovsky wrote:

quoted

From: Leon Romanovsky <leonro@nvidia.com>

<...>

quoted

  include/linux/page-flags.h         |  1 +

<...>

quoted

--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h

@@ -614,6 +614,7 @@ FOLIO_FLAG(dropbehind, FOLIO_HEAD_PAGE)
   * available at this point.
   */
  #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p))
+#define PhysHighMem(__p) (PageHighMem(phys_to_page(__p)))

This was a not so great idea to add PhysHighMem() because of "else"
below which unfolds to maze of macros and automatically generated
functions with "static inline int Page##uname ..." signature.

quoted

  #define folio_test_highmem(__f)	is_highmem_idx(folio_zonenum(__f))
  #else
  PAGEFLAG_FALSE(HighMem, highmem)

After sleeping over it, the following hunk will help:

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index dfbc4ba86bba2..2a1f346178024 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h

@@ -614,11 +614,11 @@ FOLIO_FLAG(dropbehind, FOLIO_HEAD_PAGE)
   * available at this point.
   */
  #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p))
-#define PhysHighMem(__p) (PageHighMem(phys_to_page(__p)))
  #define folio_test_highmem(__f)        is_highmem_idx(folio_zonenum(__f))
  #else
  PAGEFLAG_FALSE(HighMem, highmem)
  #endif
+#define PhysHighMem(__p) (PageHighMem(phys_to_page(__p)))

  /* Does kmap_local_folio() only allow access to one page of the folio? */
  #ifdef CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP