From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753160AbbJNMG0 (ORCPT ); Wed, 14 Oct 2015 08:06:26 -0400 Received: from foss.arm.com ([217.140.101.70]:57908 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751742AbbJNMGX (ORCPT ); Wed, 14 Oct 2015 08:06:23 -0400 Date: Wed, 14 Oct 2015 13:06:18 +0100 From: Mark Rutland To: "Suzuki K. Poulose" Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will.deacon@arm.com, steve.capper@linaro.org, marc.zyngier@arm.com, ard.biesheuvel@linaro.org, christoffer.dall@linaro.org Subject: Re: [PATCHv3 02/11] arm64: Handle section maps for swapper/idmap Message-ID: <20151014120618.GB2150@leverpostej> References: <1444821634-1689-1-git-send-email-suzuki.poulose@arm.com> <1444821634-1689-3-git-send-email-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1444821634-1689-3-git-send-email-suzuki.poulose@arm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 14, 2015 at 12:20:25PM +0100, Suzuki K. Poulose wrote: > We use section maps with 4K page size to create the swapper/idmaps. > So far we have used !64K or 4K checks to handle the case where we > use the section maps. > This patch adds a new symbol, ARM64_SWAPPER_USES_SECTION_MAPS, to > handle cases where we use section maps, instead of using the page size > symbols. > > Cc: Ard Biesheuvel > Cc: Mark Rutland > Cc: Catalin Marinas > Cc: Will Deacon > Signed-off-by: Suzuki K. Poulose > --- > arch/arm64/include/asm/kernel-pgtable.h | 31 ++++++++----- > arch/arm64/mm/mmu.c | 72 ++++++++++++++----------------- > 2 files changed, 52 insertions(+), 51 deletions(-) > > diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h > index 622929d..5876a36 100644 > --- a/arch/arm64/include/asm/kernel-pgtable.h > +++ b/arch/arm64/include/asm/kernel-pgtable.h > @@ -19,6 +19,13 @@ > #ifndef __ASM_KERNEL_PGTABLE_H > #define __ASM_KERNEL_PGTABLE_H > > +/* With 4K pages, we use section maps. */ > +#ifdef CONFIG_ARM64_4K_PAGES > +#define ARM64_SWAPPER_USES_SECTION_MAPS 1 > +#else > +#define ARM64_SWAPPER_USES_SECTION_MAPS 0 > +#endif The comment is somewhat redunant. It would be better to state why we do this for 4K and not 64K (or 16K). > @@ -406,14 +407,11 @@ static void __init map_mem(void) > * memory addressable from the initial direct kernel mapping. > * > * The initial direct kernel mapping, located at swapper_pg_dir, gives > - * us PUD_SIZE (4K pages) or PMD_SIZE (64K pages) memory starting from > - * PHYS_OFFSET (which must be aligned to 2MB as per > - * Documentation/arm64/booting.txt). > + * us PUD_SIZE (with SECTION maps, i.e, 4K) or PMD_SIZE (without > + * SECTION maps, i.e, 64K pages) memory starting from PHYS_OFFSET > + * (which must be aligned to 2MB as per Documentation/arm64/booting.txt). This didn't seem to get updated for 16K later in the series, unless I missed something. Perhaps drop the mention of 4K / 64K entirely here? > @@ -551,7 +552,7 @@ int kern_addr_valid(unsigned long addr) > return pfn_valid(pte_pfn(*pte)); > } > #ifdef CONFIG_SPARSEMEM_VMEMMAP > -#ifdef CONFIG_ARM64_64K_PAGES > +#if !ARM64_SWAPPER_USES_SECTION_MAPS This leaves the comments on the #else and #endif stale. Please update those too. Otherwise this looks good! Thanks, Mark.