From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Mon, 13 Apr 2015 17:26:46 +0100 Subject: [PATCH v3 04/11] arm64: use fixmap region for permanent FDT mapping In-Reply-To: References: <1428674035-26603-1-git-send-email-ard.biesheuvel@linaro.org> <1428674035-26603-5-git-send-email-ard.biesheuvel@linaro.org> <20150413150203.GF4076@leverpostej> <20150413152636.GH4076@leverpostej> Message-ID: <20150413162646.GK4076@leverpostej> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > I was wondering: this code now always maps the full 4 MB, also on 64k > pages, even if in the majority of cases, the actual FDT is much > smaller. Do you think there is a downside to that? The two cases I can think of as problematic are when the FDT is in the last 2M of RAM, or in a 2M region immediately before some carveout which won't use MT_NORMAL attributes. We could solve those by only mapping however many 2M chunks are necessary, or we could keep the requirement that it fits within a naturally-aligned 2M region for now. I don't see that this should yield significant problems otherwise. Mark.