Add comments to the cachemode translation tables to clarify that the default values are set as minimal supported mode, which are necessary to handle WC and WT fallback to UC- when they are not enabled.
Signed-off-by: Toshi Kani <toshi.k...@hp.com> Cc: Jan Beulich <jbeul...@suse.com> Cc: Borislav Petkov <b...@suse.de> Cc: Ingo Molnar <mi...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> --- Ingo, please replace the patch below with this patch. https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg937806.html --- arch/x86/mm/init.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 8533b46..1d8a83d 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -30,8 +30,11 @@ /* * Tables translating between page_cache_type_t and pte encoding. * - * Minimal supported modes are defined statically, they are modified - * during bootup if more supported cache modes are available. + * The default values are defined statically as minimal supported mode; + * WC and WT fall back to UC-. pat_init() updates these values to support + * more cache modes, WC and WT, when it is safe to do so. See pat_init() + * for the details. Note, __early_ioremap() used during early boot-time + * takes pgprot_t (pte encoding) and does not use these tables. * * Index into __cachemode2pte_tbl[] is the cachemode. * -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
