From patchwork Sat Oct 10 15:12:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Saenz Julienne X-Patchwork-Id: 1319385 Return-Path: Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0534C433DF for ; Sat, 10 Oct 2020 23:08:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9BAB2075E for ; Sat, 10 Oct 2020 23:08:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729873AbgJJW5N (ORCPT ); Sat, 10 Oct 2020 18:57:13 -0400 Received: from mx2.suse.de ([195.135.220.15]:48186 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732221AbgJJTnx (ORCPT ); Sat, 10 Oct 2020 15:43:53 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 45896B14F; Sat, 10 Oct 2020 15:12:48 +0000 (UTC) From: Nicolas Saenz Julienne To: robh+dt@kernel.org, catalin.marinas@arm.com, hch@lst.de, ardb@kernel.org, linux-kernel@vger.kernel.org Cc: robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org, jeremy.linton@arm.com, iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, Nicolas Saenz Julienne , Will Deacon Subject: [PATCH v2 4/5] arm64: mm: Dynamically resize zone_dma_bits based on system's constraints Date: Sat, 10 Oct 2020 17:12:34 +0200 Message-Id: <20201010151235.20585-5-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201010151235.20585-1-nsaenzjulienne@suse.de> References: <20201010151235.20585-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With the help of of_dma_safe_phys_limit() we can get the topmost physical address accessible for DMA to the whole system and use that information to properly setup zone_dma_bits. Signed-off-by: Nicolas Saenz Julienne --- arch/arm64/include/asm/processor.h | 1 + arch/arm64/mm/init.c | 5 ++--- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index fce8cbecd6bc..c09d3f1a9a6b 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -97,6 +97,7 @@ extern phys_addr_t arm64_dma_phys_limit; #define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1) +#define ZONE_DMA_BITS_DEFAULT 32 struct debug_info { #ifdef CONFIG_HAVE_HW_BREAKPOINT diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 0eca5865dcb1..5934df93bf4d 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -42,8 +42,6 @@ #include #include -#define ARM64_ZONE_DMA_BITS 30 - /* * We need to be able to catch inadvertent references to memstart_addr * that occur (potentially in generic code) before arm64_memblock_init() @@ -196,7 +194,8 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) unsigned long max_zone_pfns[MAX_NR_ZONES] = {0}; #ifdef CONFIG_ZONE_DMA - zone_dma_bits = ARM64_ZONE_DMA_BITS; + zone_dma_bits = min(zone_dma_bits, + (unsigned int)ilog2(of_dma_safe_phys_limit())); if (IS_ENABLED(CONFIG_ACPI)) { extern unsigned int acpi_iort_get_zone_dma_size(void);