From patchwork Fri Oct 20 05:40:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13430065 X-Patchwork-Delegate: kuba@kernel.org 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 51FF1C15D for ; Fri, 20 Oct 2023 05:40:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="KzFFarec" Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2057F1A4; Thu, 19 Oct 2023 22:40:47 -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=KxnTs7gymzuYQJ4ABXvh3JzqxQqiL8GoV+1jwXDsc7A=; b=KzFFarecVywzyeEpwpUH/45E+L jKc1bbjilM70qeziPcc8ZLZnR5Gs8xv/vd5Nb4NPEbEAURbvbJaKInpB0Z5sBrOQD/QWTBSkS5crI MyWtpoAhbO/bdEPAV4v8tnRr58OljuULFTXtXhe14sgL3pnZ5pIy/9kR44Up6QJ1FPAdNn9fhyxLn KkPiXnDXLx9Hrko+J/4cWTzDN2O5fY+qc5zJJ9+sqShUoP1DJf7+1DYuhJqIRHhVJeSRFWOthVeKy 5Onc7Q6oWGn54r9qS2mhNTiXzOyHfELJN+FJDtSI+2QahG22L+6FfybpwjKGF6CzQ8gqTHgOHuJOV APa0iJjw==; 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 1qtiFW-001Gjq-1K; Fri, 20 Oct 2023 05:40:42 +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 6/8] net: fec: use dma_alloc_noncoherent for data cache enabled coldfire Date: Fri, 20 Oct 2023 07:40:22 +0200 Message-Id: <20231020054024.78295-7-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 X-Patchwork-Delegate: kuba@kernel.org Coldfire platforms with data caches can't properly implement dma_alloc_coherent and currently just return noncoherent memory from dma_alloc_coherent. The fec driver than works around this with a flush of all caches in the receive path. Make this hack a little less bad by using the explicit dma_alloc_noncoherent API and documenting the hacky cache flushes so that the DMA API level hack can be removed. Also replace the check for CONFIG_M532x for said hack with a check for COLDFIRE && !COLDFIRE_COHERENT_DMA. While m532x is the only such platform with a fec module, this makes the code more consistent and easier to follow. Signed-off-by: Christoph Hellwig Reviewed-by: Greg Ungerer Tested-by: Greg Ungerer --- drivers/net/ethernet/freescale/fec_main.c | 86 ++++++++++++++++++++--- 1 file changed, 76 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 77c8e9cfb44562..c5e370570f6ec6 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -406,6 +406,70 @@ static void fec_dump(struct net_device *ndev) } while (bdp != txq->bd.base); } +/* + * Coldfire does not support DMA coherent allocations, and has historically used + * a band-aid with a manual flush in fec_enet_rx_queue. + */ +#if defined(CONFIG_COLDFIRE) && !defined(CONFIG_COLDFIRE_COHERENT_DMA) +static void *fec_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, + gfp_t gfp) +{ + return dma_alloc_noncoherent(dev, size, handle, DMA_BIDIRECTIONAL, gfp); +} + +static void fec_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle) +{ + dma_free_noncoherent(dev, size, cpu_addr, handle, DMA_BIDIRECTIONAL); +} +#else /* !CONFIG_COLDFIRE || CONFIG_COLDFIRE_COHERENT_DMA */ +static void *fec_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, + gfp_t gfp) +{ + return dma_alloc_coherent(dev, size, handle, gfp); +} + +static void fec_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle) +{ + dma_free_coherent(dev, size, cpu_addr, handle); +} +#endif /* !CONFIG_COLDFIRE || CONFIG_COLDFIRE_COHERENT_DMA */ + +struct fec_dma_devres { + size_t size; + void *vaddr; + dma_addr_t dma_handle; +}; + +static void fec_dmam_release(struct device *dev, void *res) +{ + struct fec_dma_devres *this = res; + + fec_dma_free(dev, this->size, this->vaddr, this->dma_handle); +} + +static void *fec_dmam_alloc(struct device *dev, size_t size, dma_addr_t *handle, + gfp_t gfp) +{ + struct fec_dma_devres *dr; + void *vaddr; + + dr = devres_alloc(fec_dmam_release, sizeof(*dr), gfp); + if (!dr) + return NULL; + vaddr = fec_dma_alloc(dev, size, handle, gfp); + if (!vaddr) { + devres_free(dr); + return NULL; + } + dr->vaddr = vaddr; + dr->dma_handle = *handle; + dr->size = size; + devres_add(dev, dr); + return vaddr; +} + static inline bool is_ipv4_pkt(struct sk_buff *skb) { return skb->protocol == htons(ETH_P_IP) && ip_hdr(skb)->version == 4; @@ -1660,7 +1724,11 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id) } #endif -#ifdef CONFIG_M532x +#if defined(CONFIG_COLDFIRE) && !defined(CONFIG_COLDFIRE_COHERENT_DMA) + /* + * Hacky flush of all caches instead of using the DMA API for the TSO + * headers. + */ flush_cache_all(); #endif rxq = fep->rx_queue[queue_id]; @@ -3288,10 +3356,9 @@ static void fec_enet_free_queue(struct net_device *ndev) for (i = 0; i < fep->num_tx_queues; i++) if (fep->tx_queue[i] && fep->tx_queue[i]->tso_hdrs) { txq = fep->tx_queue[i]; - dma_free_coherent(&fep->pdev->dev, - txq->bd.ring_size * TSO_HEADER_SIZE, - txq->tso_hdrs, - txq->tso_hdrs_dma); + fec_dma_free(&fep->pdev->dev, + txq->bd.ring_size * TSO_HEADER_SIZE, + txq->tso_hdrs, txq->tso_hdrs_dma); } for (i = 0; i < fep->num_rx_queues; i++) @@ -3321,10 +3388,9 @@ static int fec_enet_alloc_queue(struct net_device *ndev) txq->tx_stop_threshold = FEC_MAX_SKB_DESCS; txq->tx_wake_threshold = FEC_MAX_SKB_DESCS + 2 * MAX_SKB_FRAGS; - txq->tso_hdrs = dma_alloc_coherent(&fep->pdev->dev, + txq->tso_hdrs = fec_dma_alloc(&fep->pdev->dev, txq->bd.ring_size * TSO_HEADER_SIZE, - &txq->tso_hdrs_dma, - GFP_KERNEL); + &txq->tso_hdrs_dma, GFP_KERNEL); if (!txq->tso_hdrs) { ret = -ENOMEM; goto alloc_failed; @@ -4043,8 +4109,8 @@ static int fec_enet_init(struct net_device *ndev) bd_size = (fep->total_tx_ring_size + fep->total_rx_ring_size) * dsize; /* Allocate memory for buffer descriptors. */ - cbd_base = dmam_alloc_coherent(&fep->pdev->dev, bd_size, &bd_dma, - GFP_KERNEL); + cbd_base = fec_dmam_alloc(&fep->pdev->dev, bd_size, &bd_dma, + GFP_KERNEL); if (!cbd_base) { ret = -ENOMEM; goto free_queue_mem;