From patchwork Wed Jul 17 15:31:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Saenz Julienne X-Patchwork-Id: 11048065 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DE9F31398 for ; Wed, 17 Jul 2019 15:32:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C938228754 for ; Wed, 17 Jul 2019 15:32:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BBFF528750; Wed, 17 Jul 2019 15:32:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 58A1628750 for ; Wed, 17 Jul 2019 15:32:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=EYPZq+zNrLhshy9rqSqH6fsCNQWcQtzcvFAbxK2uHlw=; b=B77UwBkhvclfNx RziII+bZiQUxOE7Y1A1vQd43RpJUGf4GvbchSadHFeS2SKui0MDBV2gxsZAcO6bi0Byq+6GZ5zza4 ygSLz5xGWdzb4IJo2MOvvigfTJ3ebHVfN7dLHbL51O9s1xM3sz07EV/cx+r3Xe0jnDLK/Mn29mhU1 1tl4998fa9jsapFYQA/206mN93N6Z8jfzOtcOfsfekl6PvJceNkfAc2TBoAiEoHG/wGAA9o3sPagu LNdEw4yWM7NbBXIgvYbWvdjDACwIOb+OUM9wfFcr6Botu9QzuVephFSbkp8umfBfu7A0kL6boaPzW O4nVfb6xgmbshgyq3tXw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hnlum-0004I7-LT; Wed, 17 Jul 2019 15:32:20 +0000 Received: from mx2.suse.de ([195.135.220.15] helo=mx1.suse.de) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hnluG-0003jn-HG for linux-arm-kernel@lists.infradead.org; Wed, 17 Jul 2019 15:31:51 +0000 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id DEE36B039; Wed, 17 Jul 2019 15:31:45 +0000 (UTC) From: Nicolas Saenz Julienne To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [RFC 2/4] arm64: mm: parse dma-ranges in order to better estimate arm64_dma_phys_limit Date: Wed, 17 Jul 2019 17:31:33 +0200 Message-Id: <20190717153135.15507-3-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190717153135.15507-1-nsaenzjulienne@suse.de> References: <20190717153135.15507-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190717_083148_864991_03F6D060 X-CRM114-Status: GOOD ( 17.10 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stefan.wahren@i2se.com, f.fainelli@gmail.com, catalin.marinas@arm.com, phil@raspberrypi.org, robin.murphy@arm.com, Jisheng.Zhang@synaptics.com, mbrugger@suse.com, will@kernel.org, hch@lst.de, Nicolas Saenz Julienne , m.szyprowski@samsung.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The dma physical limit has so far been calculated based on the memory size and the assumption that dma would be at least able to address the first 4 GB. This turned out no to be true with the Raspberry Pi 4 which, on it's main interconnect, can only address the first GB of memory, even though it might have up to 4 GB. With the current miscalculated dma physical limit the contiguous memory reserve is located in an inaccessible area for most of the board's devices. To solve this we now scan the device tree for the 'dma-ranges' property on the root or interconnect nodes, which allows us to calculate the lowest common denominator dma physical limit. If no dma-ranges is available, we'll default to the old scheme. Signed-off-by: Nicolas Saenz Julienne --- arch/arm64/mm/init.c | 61 +++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 57 insertions(+), 4 deletions(-) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 6112d6c90fa8..5708adf0db52 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -163,14 +163,67 @@ static void __init reserve_elfcorehdr(void) { } #endif /* CONFIG_CRASH_DUMP */ + +static int __init early_init_dt_scan_dma_ranges(unsigned long node, + const char *uname, int depth, void *data) +{ + phys_addr_t *dma_phys_limit = data; + u64 phys_addr, dma_addr, size; + int dma_addr_cells; + const __be32 *reg; + const void *prop; + int len; + + /* We keep looking if this isn't the root node or an interconnect */ + if (!(depth == 0 || + (depth == 1 && of_flat_dt_is_compatible(node, "simple-bus")))) + return 0; + + prop = of_get_flat_dt_prop(node, "#address-cells", NULL); + if (prop) + dma_addr_cells = be32_to_cpup(prop); + else + dma_addr_cells = 1; /* arm64's default addr_cell size */ + + reg = of_get_flat_dt_prop(node, "dma-ranges", &len); + if (!reg || + len < (dma_addr_cells + dt_root_addr_cells + dt_root_size_cells)) + return 0; + + dma_addr = dt_mem_next_cell(dma_addr_cells, ®); + phys_addr = dt_mem_next_cell(dt_root_addr_cells, ®); + size = dt_mem_next_cell(dt_root_size_cells, ®); + + /* We're in ZONE_DMA32 */ + if (size > (1ULL << 32)) + size = 1ULL << 32; + + if (*dma_phys_limit > (phys_addr + size)) + *dma_phys_limit = phys_addr + size; + + return 0; +} + /* - * Return the maximum physical address for ZONE_DMA32 (DMA_BIT_MASK(32)). It - * currently assumes that for memory starting above 4G, 32-bit devices will - * use a DMA offset. + * Return the maximum physical address for ZONE_DMA32. It currently assumes + * that for memory starting above 4G, 32-bit devices will use a DMA offset. */ static phys_addr_t __init max_zone_dma_phys(void) { - phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32); + phys_addr_t dma_phys_limit = ~0; + phys_addr_t offset; + + /* + * We walk the whole fdt looking for nodes with dma-ranges, calculate + * the max_zone_dma_phys for them and keep going. We end-up getting the + * lowest common denominator of all the matches. + */ + of_scan_flat_dt(early_init_dt_scan_dma_ranges, &dma_phys_limit); + if (dma_phys_limit != ~0) + return dma_phys_limit; + + /* If no dma-ranges property was found we try to infer the value */ + offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32); return min(offset + (1ULL << 32), memblock_end_of_DRAM()); }