From patchwork Fri Oct 20 05:40:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13430062 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A13A36FD9 for ; Fri, 20 Oct 2023 05:40:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="TYTcVET4" Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F7FCD51; Thu, 19 Oct 2023 22:40:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=2NdcUI9DyUHr2lanL5FVnDyDlgBIUYjE1oxDB5o8nXU=; b=TYTcVET4VKT5r76wzwXvbAUVaC xk+HX35iQzysz4uDIP1BUzhTLzDBe+6FcYOWatR2FycjNm87ncTx2D/ZmwP0bpNGna3HYe5clppzo /4b3HaUjeSsmIxXaiXeTeCIO8AaYsoKHVDTvZx7jIndMdYWZd81jquLFuJEvLWAnK/ALBHuOWdPL0 AlFvO0RNXgLAgttQEEq4TrNMVib75O9jbtxfT3kPMndACfjRf4KIDYCOEb4CY0TjTQ8d1B6QChEdd Feleho09GFdNhmU+at3/Rk/DHY4W5PeQ6Xi+1hmAqqYlcI2EcrajCs09QtbGyKbRpWx7WDWCdYfrC Zl1C+6Dg==; Received: from 2a02-8389-2341-5b80-39d3-4735-9a3c-88d8.cable.dynamic.v6.surfer.at ([2a02:8389:2341:5b80:39d3:4735:9a3c:88d8] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1qtiFP-001Gib-0S; Fri, 20 Oct 2023 05:40:35 +0000 From: Christoph Hellwig To: Greg Ungerer , iommu@lists.linux.dev Cc: Robin Murphy , Marek Szyprowski , Geert Uytterhoeven , Wei Fang , Shenwei Wang , Clark Wang , NXP Linux Team , linux-m68k@lists.linux-m68k.org, netdev@vger.kernel.org Subject: [PATCH 3/8] dma-direct: simplify the use atomic pool logic in dma_direct_alloc Date: Fri, 20 Oct 2023 07:40:19 +0200 Message-Id: <20231020054024.78295-4-hch@lst.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231020054024.78295-1-hch@lst.de> References: <20231020054024.78295-1-hch@lst.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html The logic in dma_direct_alloc when to use the atomic pool vs remapping grew a bit unreadable. Consolidate it into a single check, and clean up the set_uncached vs remap logic a bit as well. Signed-off-by: Christoph Hellwig Reviewed-by: Robin Murphy Reviewed-by: Greg Ungerer Tested-by: Greg Ungerer --- kernel/dma/direct.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index c078090cd38ecc..9657ef7c055eaa 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -234,27 +234,22 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_handle); /* - * Otherwise remap if the architecture is asking for it. But - * given that remapping memory is a blocking operation we'll - * instead have to dip into the atomic pools. + * Otherwise we require the architecture to either be able to + * mark arbitrary parts of the kernel direct mapping uncached, + * or remapped it uncached. */ + set_uncached = IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED); remap = IS_ENABLED(CONFIG_DMA_DIRECT_REMAP); - if (remap) { - if (dma_direct_use_pool(dev, gfp)) - return dma_direct_alloc_from_pool(dev, size, - dma_handle, gfp); - } else { - if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED)) - return NULL; - set_uncached = true; - } + if (!set_uncached && !remap) + return NULL; } /* - * Decrypting memory may block, so allocate the memory from the atomic - * pools if we can't block. + * Remapping or decrypting memory may block, allocate the memory from + * the atomic pools instead if we aren't allowed block. */ - if (force_dma_unencrypted(dev) && dma_direct_use_pool(dev, gfp)) + if ((remap || force_dma_unencrypted(dev)) && + dma_direct_use_pool(dev, gfp)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); /* we always manually zero the memory once we are done */