From patchwork Sat Dec 2 13:42:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jisheng Zhang X-Patchwork-Id: 13476996 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9BF56C4167B for ; Sat, 2 Dec 2023 13:55:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=U+rpNmxbrlCA5xuqsINj2tOPyjumJrlKsJm+Ke+Zdv4=; b=Hmn8GoJTloEdDY xyixCa5WOl+DpqBgoev3vQK37MragqchL6rKTI53SLLwkX1qL2tia8GEWeUAh6zegN8m9OgDstaYn 0zgQSBCLCN1zAsYSJ4tLMzEVUvxGlkINMCNwwkyXga0OAbgdkTE6fmKH9D6t4PWlLogRphRmKidMx uPmA2Rijf1D5fg4g2rHnDtQS2nyP1t2jGRsg9ZCSLiDTboZTKnmmkGhzVkz2H97CJAnbKIK1pHt9X rD6F6polJDSd1Tk66cIctBWGU1thp4tFXqqMhRgrXuBW29nWC1vP8HJ0S2LZw1bQIlz7PgMubDyTS C5LAHsyvCZ1DHrmPs6SQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r9QSR-00Flvm-1h; Sat, 02 Dec 2023 13:54:59 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r9QSO-00Flug-35 for linux-riscv@lists.infradead.org; Sat, 02 Dec 2023 13:54:58 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id 46A91B81C18; Sat, 2 Dec 2023 13:54:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 848CCC433C7; Sat, 2 Dec 2023 13:54:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1701525290; bh=bomojrOAMU2gHGxmYDLygOQUoO4KABGe2Me37Cc0YE0=; h=From:To:Cc:Subject:Date:From; b=TLDhW872Qeq6T2lOiL/tmbelYRkMW2rIQaE4jkN2Q7OnQKvnK0+B81Hngx2UZIR6/ ETWx7tcNYE1TVKJ/8r0TWFldBBt2c6NYUdKvD/W53sET147ei1ih0uJTMZ62Xg1vv+ D/4V4wCKLUKiU811CGfxekWJC4K6Fggm+IeihHucqryvW612yFnA8LGBAEtNM8svgs vMuRCcbUFUwuUPLb6beNdkzHMJzbgsMvem8OkFLCefLaFbR1d0cEhJFlyN0VhjWcFn yRoteBGcCKVHJ9iOC9iJtNNYym5kkvhP81ByRe4F8vGM9m0Du3s0rI+Ok4JtfJDPIx Vyg8Ib3CbhMAQ== From: Jisheng Zhang To: Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] riscv: mm: still create swiotlb buffer for kmalloc() bouncing if required Date: Sat, 2 Dec 2023 21:42:24 +0800 Message-Id: <20231202134224.4029-1-jszhang@kernel.org> X-Mailer: git-send-email 2.40.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231202_055457_135037_16527584 X-CRM114-Status: GOOD ( 12.27 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org After commit f51f7a0fc2f4 ("riscv: enable DMA_BOUNCE_UNALIGNED_KMALLOC for !dma_coherent"), for non-coherent platforms with less than 4GB memory, we rely on users to pass "swiotlb=mmnn,force" kernel parameters to enable DMA bouncing for unaligned kmalloc() buffers. Now let's go further: If no bouncing needed for ZONE_DMA, let kernel automatically allocate 1MB swiotlb buffer per 1GB of RAM for kmalloc() bouncing on non-coherent platforms, so that no need to pass "swiotlb=mmnn,force" any more. The math of "1MB swiotlb buffer per 1GB of RAM for kmalloc() bouncing" is taken from arm64. Users can still force smaller swiotlb buffer by passing "swiotlb=mmnn". Signed-off-by: Jisheng Zhang Reviewed-by: Alexandre Ghiti --- since v2: - fix build error if CONFIG_RISCV_DMA_NONCOHERENT=n arch/riscv/include/asm/cache.h | 2 +- arch/riscv/mm/init.c | 16 +++++++++++++++- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/arch/riscv/include/asm/cache.h b/arch/riscv/include/asm/cache.h index 2174fe7bac9a..570e9d8acad1 100644 --- a/arch/riscv/include/asm/cache.h +++ b/arch/riscv/include/asm/cache.h @@ -26,8 +26,8 @@ #ifndef __ASSEMBLY__ -#ifdef CONFIG_RISCV_DMA_NONCOHERENT extern int dma_cache_alignment; +#ifdef CONFIG_RISCV_DMA_NONCOHERENT #define dma_get_cache_alignment dma_get_cache_alignment static inline int dma_get_cache_alignment(void) { diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 2e011cbddf3a..cbcb9918f721 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -162,11 +162,25 @@ static void print_vm_layout(void) { } void __init mem_init(void) { + bool swiotlb = max_pfn > PFN_DOWN(dma32_phys_limit); #ifdef CONFIG_FLATMEM BUG_ON(!mem_map); #endif /* CONFIG_FLATMEM */ - swiotlb_init(max_pfn > PFN_DOWN(dma32_phys_limit), SWIOTLB_VERBOSE); + if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) && !swiotlb && + dma_cache_alignment != 1) { + /* + * If no bouncing needed for ZONE_DMA, allocate 1MB swiotlb + * buffer per 1GB of RAM for kmalloc() bouncing on + * non-coherent platforms. + */ + unsigned long size = + DIV_ROUND_UP(memblock_phys_mem_size(), 1024); + swiotlb_adjust_size(min(swiotlb_size_or_default(), size)); + swiotlb = true; + } + + swiotlb_init(swiotlb, SWIOTLB_VERBOSE); memblock_free_all(); print_vm_layout();