From: Leonid Yegoshin <[email protected]> Provide hooks that allow architectures with aliasing cache to align mapping address of high pages according to their color. Such architectures may enforce similar coloring of low- and high-memory page mappings and reuse existing cache management functions to support highmem.
Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: David Rientjes <[email protected]> Signed-off-by: Leonid Yegoshin <[email protected]> [ Max: extract architecture-independent part of the original patch, clean up checkpatch and build warnings. ] Signed-off-by: Max Filippov <[email protected]> --- Changes since the initial version: - define set_pkmap_color(pg, cl) as do { } while (0) instead of /* */; - rename is_no_more_pkmaps to no_more_pkmaps; - change 'if (count > 0)' to 'if (count)' to better match the original code behavior; mm/highmem.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/mm/highmem.c b/mm/highmem.c index b32b70c..88fb62e 100644 --- a/mm/highmem.c +++ b/mm/highmem.c @@ -44,6 +44,14 @@ DEFINE_PER_CPU(int, __kmap_atomic_idx); */ #ifdef CONFIG_HIGHMEM +#ifndef ARCH_PKMAP_COLORING +#define set_pkmap_color(pg, cl) do { } while (0) +#define get_last_pkmap_nr(p, cl) (p) +#define get_next_pkmap_nr(p, cl) (((p) + 1) & LAST_PKMAP_MASK) +#define no_more_pkmaps(p, cl) (!(p)) +#define get_next_pkmap_counter(c, cl) ((c) - 1) +#endif + unsigned long totalhigh_pages __read_mostly; EXPORT_SYMBOL(totalhigh_pages); @@ -161,19 +169,24 @@ static inline unsigned long map_new_virtual(struct page *page) { unsigned long vaddr; int count; + int color __maybe_unused; + + set_pkmap_color(page, color); + last_pkmap_nr = get_last_pkmap_nr(last_pkmap_nr, color); start: count = LAST_PKMAP; /* Find an empty entry */ for (;;) { - last_pkmap_nr = (last_pkmap_nr + 1) & LAST_PKMAP_MASK; - if (!last_pkmap_nr) { + last_pkmap_nr = get_next_pkmap_nr(last_pkmap_nr, color); + if (no_more_pkmaps(last_pkmap_nr, color)) { flush_all_zero_pkmaps(); count = LAST_PKMAP; } if (!pkmap_count[last_pkmap_nr]) break; /* Found a usable entry */ - if (--count) + count = get_next_pkmap_counter(count, color); + if (count) continue; /* -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
