Re: [PATCH v6 03/16] dma-debug: refactor to use physical addresses for page mapping

Leon Romanovsky
2025-09-09T19:37:53Z

On Tue, Sep 09, 2025 at 04:27:31PM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@nvidia.com>

<...>

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

<...>

> --- 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.

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

Thanks