From patchwork Tue Sep 29 07:37:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ikjoon Jang X-Patchwork-Id: 11805095 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 27532139A for ; Tue, 29 Sep 2020 07:38:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 051FD20848 for ; Tue, 29 Sep 2020 07:38:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="GvVQ+kAG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727557AbgI2Hiq (ORCPT ); Tue, 29 Sep 2020 03:38:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727555AbgI2Hip (ORCPT ); Tue, 29 Sep 2020 03:38:45 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25B9AC0613D2 for ; Tue, 29 Sep 2020 00:38:45 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id g29so3175102pgl.2 for ; Tue, 29 Sep 2020 00:38:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=rdWz+ZyG62m5arW+Qy6bGdg2LVkta9/ER2EhDPjnR0s=; b=GvVQ+kAGZRMHDvFY+dX0CiorSG0wudjaaSuFKXMLGOMZCTG/Ve9qYDA+7MGGLXXAcT VuHqgAl5RBIeWHgeoonxdMFugZ3JceAqI/WLejNr1SjJODLRcB2ZWT2jrtmIUSaXX/bu cN5O8FcycZx0hgad1TZdbxAK9r8oErQLgTFHQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=rdWz+ZyG62m5arW+Qy6bGdg2LVkta9/ER2EhDPjnR0s=; b=dZY5FubaJUXCR2XHMTi/mOIHQ9mJiPzwXg2YJ95UwXQyxISA60Bk47bppQnDA9MXTG 2Lc7MT6teAy+yvPVS5w22hHZ74uzCYZAB0Vwd6LILhXD0t+IWZjWGFNWDxrSVimAEivY +BIYbjyUD87/OvalkItIzkYkEpQCcLRZmw3TgCQ2hZu8bWK6Eup1kQ6j/E76wv/VTvDW InTHTQvLuyk7nHgeySFPR31Fon3Avd4K/beW6jEsJEEXDcwwtxvs1eCbHJdC9yRmX4pk agcYQzhENMlPOFtz7gwdqczKEmTGwRyssMWrzOgg/vfq8C0E5zDHoj0FTu45VaQSdC7w F7Jg== X-Gm-Message-State: AOAM5336yyhEcziA3Tjb2OZUTGHmWQeBS7kPAcSHx57ED19efcPNuOYU He0PmbA9LqqFlNhrGZDfKPIKsQ== X-Google-Smtp-Source: ABdhPJwLJTU9cxoMZuGNs9a4koIqVDQ2Ze6yK26tMjSimBv2MYtu7K5VT9yr3F3lAgWk7FHF0RYc2A== X-Received: by 2002:a17:902:c213:b029:d2:564d:8352 with SMTP id 19-20020a170902c213b02900d2564d8352mr3350077pll.54.1601365124558; Tue, 29 Sep 2020 00:38:44 -0700 (PDT) Received: from ikjn-p920.tpe.corp.google.com ([2401:fa00:1:10:f693:9fff:fef4:a8fc]) by smtp.gmail.com with ESMTPSA id e13sm3737317pjy.38.2020.09.29.00.38.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Sep 2020 00:38:43 -0700 (PDT) From: Ikjoon Jang To: Rob Herring , Mark Brown , devicetree@vger.kernel.org, linux-spi@vger.kernel.org, linux-mtd@lists.infradead.org Cc: Ikjoon Jang , Chuanhong Guo , Matthias Brugger , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org Subject: [PATCH v4 2/4] spi: spi-mtk-nor: use dma_alloc_coherent() for bounce buffer Date: Tue, 29 Sep 2020 15:37:53 +0800 Message-Id: <20200929153320.v4.2.I06cb65401ab5ad63ea30c4788d26633928d80f38@changeid> X-Mailer: git-send-email 2.28.0.709.gb0816b6eb0-goog In-Reply-To: <20200929073755.3741416-1-ikjn@chromium.org> References: <20200929073755.3741416-1-ikjn@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org Use dma_alloc_coherent() for bounce buffer instead of kmalloc() to make sure the bounce buffer to be allocated within its DMAable range. Additionally, add an internal helper need_bounce() function checking whether op's data buffer is DMAable. Reviewed-by: Chuanhong Guo Signed-off-by: Ikjoon Jang --- Changes in v4: - No changes since v3 Changes in v3: - simplify function names - restore back padding bytes to bounce buffer omitted in v2 drivers/spi/spi-mtk-nor.c | 93 +++++++++++++++++++++------------------ 1 file changed, 51 insertions(+), 42 deletions(-) diff --git a/drivers/spi/spi-mtk-nor.c b/drivers/spi/spi-mtk-nor.c index 6e6ca2b8e6c8..cfb9a2450962 100644 --- a/drivers/spi/spi-mtk-nor.c +++ b/drivers/spi/spi-mtk-nor.c @@ -96,6 +96,7 @@ struct mtk_nor { struct device *dev; void __iomem *base; u8 *buffer; + dma_addr_t buffer_dma; struct clk *spi_clk; struct clk *ctlr_clk; unsigned int spi_freq; @@ -144,6 +145,11 @@ static void mtk_nor_set_addr(struct mtk_nor *sp, const struct spi_mem_op *op) } } +static bool need_bounce(struct mtk_nor *sp, const struct spi_mem_op *op) +{ + return ((uintptr_t)op->data.buf.in & MTK_NOR_DMA_ALIGN_MASK); +} + static bool mtk_nor_match_read(const struct spi_mem_op *op) { int dummy = 0; @@ -169,6 +175,7 @@ static bool mtk_nor_match_read(const struct spi_mem_op *op) static int mtk_nor_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op) { + struct mtk_nor *sp = spi_controller_get_devdata(mem->spi->master); size_t len; if (!op->data.nbytes) @@ -180,8 +187,7 @@ static int mtk_nor_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op) if ((op->addr.val & MTK_NOR_DMA_ALIGN_MASK) || (op->data.nbytes < MTK_NOR_DMA_ALIGN)) op->data.nbytes = 1; - else if (!((ulong)(op->data.buf.in) & - MTK_NOR_DMA_ALIGN_MASK)) + else if (!need_bounce(sp, op)) op->data.nbytes &= ~MTK_NOR_DMA_ALIGN_MASK; else if (op->data.nbytes > MTK_NOR_BOUNCE_BUF_SIZE) op->data.nbytes = MTK_NOR_BOUNCE_BUF_SIZE; @@ -261,19 +267,12 @@ static void mtk_nor_setup_bus(struct mtk_nor *sp, const struct spi_mem_op *op) mtk_nor_rmw(sp, MTK_NOR_REG_BUSCFG, reg, MTK_NOR_BUS_MODE_MASK); } -static int mtk_nor_read_dma(struct mtk_nor *sp, u32 from, unsigned int length, - u8 *buffer) +static int mtk_nor_dma_exec(struct mtk_nor *sp, u32 from, unsigned int length, + dma_addr_t dma_addr) { int ret = 0; ulong delay; u32 reg; - dma_addr_t dma_addr; - - dma_addr = dma_map_single(sp->dev, buffer, length, DMA_FROM_DEVICE); - if (dma_mapping_error(sp->dev, dma_addr)) { - dev_err(sp->dev, "failed to map dma buffer.\n"); - return -EINVAL; - } writel(from, sp->base + MTK_NOR_REG_DMA_FADR); writel(dma_addr, sp->base + MTK_NOR_REG_DMA_DADR); @@ -298,30 +297,49 @@ static int mtk_nor_read_dma(struct mtk_nor *sp, u32 from, unsigned int length, (delay + 1) * 100); } - dma_unmap_single(sp->dev, dma_addr, length, DMA_FROM_DEVICE); if (ret < 0) dev_err(sp->dev, "dma read timeout.\n"); return ret; } -static int mtk_nor_read_bounce(struct mtk_nor *sp, u32 from, - unsigned int length, u8 *buffer) +static int mtk_nor_read_bounce(struct mtk_nor *sp, const struct spi_mem_op *op) { unsigned int rdlen; int ret; - if (length & MTK_NOR_DMA_ALIGN_MASK) - rdlen = (length + MTK_NOR_DMA_ALIGN) & ~MTK_NOR_DMA_ALIGN_MASK; + if (op->data.nbytes & MTK_NOR_DMA_ALIGN_MASK) + rdlen = (op->data.nbytes + MTK_NOR_DMA_ALIGN) & ~MTK_NOR_DMA_ALIGN_MASK; else - rdlen = length; + rdlen = op->data.nbytes; - ret = mtk_nor_read_dma(sp, from, rdlen, sp->buffer); - if (ret) - return ret; + ret = mtk_nor_dma_exec(sp, op->addr.val, rdlen, sp->buffer_dma); - memcpy(buffer, sp->buffer, length); - return 0; + if (!ret) + memcpy(op->data.buf.in, sp->buffer, op->data.nbytes); + + return ret; +} + +static int mtk_nor_read_dma(struct mtk_nor *sp, const struct spi_mem_op *op) +{ + int ret; + dma_addr_t dma_addr; + + if (need_bounce(sp, op)) + return mtk_nor_read_bounce(sp, op); + + dma_addr = dma_map_single(sp->dev, op->data.buf.in, + op->data.nbytes, DMA_FROM_DEVICE); + + if (dma_mapping_error(sp->dev, dma_addr)) + return -EINVAL; + + ret = mtk_nor_dma_exec(sp, op->addr.val, op->data.nbytes, dma_addr); + + dma_unmap_single(sp->dev, dma_addr, op->data.nbytes, DMA_FROM_DEVICE); + + return ret; } static int mtk_nor_read_pio(struct mtk_nor *sp, const struct spi_mem_op *op) @@ -425,15 +443,8 @@ static int mtk_nor_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) if (op->data.nbytes == 1) { mtk_nor_set_addr(sp, op); return mtk_nor_read_pio(sp, op); - } else if (((ulong)(op->data.buf.in) & - MTK_NOR_DMA_ALIGN_MASK)) { - return mtk_nor_read_bounce(sp, op->addr.val, - op->data.nbytes, - op->data.buf.in); } else { - return mtk_nor_read_dma(sp, op->addr.val, - op->data.nbytes, - op->data.buf.in); + return mtk_nor_read_dma(sp, op); } } @@ -588,7 +599,6 @@ static int mtk_nor_probe(struct platform_device *pdev) struct spi_controller *ctlr; struct mtk_nor *sp; void __iomem *base; - u8 *buffer; struct clk *spi_clk, *ctlr_clk; int ret, irq; @@ -604,16 +614,6 @@ static int mtk_nor_probe(struct platform_device *pdev) if (IS_ERR(ctlr_clk)) return PTR_ERR(ctlr_clk); - buffer = devm_kmalloc(&pdev->dev, - MTK_NOR_BOUNCE_BUF_SIZE + MTK_NOR_DMA_ALIGN, - GFP_KERNEL); - if (!buffer) - return -ENOMEM; - - if ((ulong)buffer & MTK_NOR_DMA_ALIGN_MASK) - buffer = (u8 *)(((ulong)buffer + MTK_NOR_DMA_ALIGN) & - ~MTK_NOR_DMA_ALIGN_MASK); - ctlr = spi_alloc_master(&pdev->dev, sizeof(*sp)); if (!ctlr) { dev_err(&pdev->dev, "failed to allocate spi controller\n"); @@ -633,13 +633,22 @@ static int mtk_nor_probe(struct platform_device *pdev) sp = spi_controller_get_devdata(ctlr); sp->base = base; - sp->buffer = buffer; sp->has_irq = false; sp->wbuf_en = false; sp->ctlr = ctlr; sp->dev = &pdev->dev; sp->spi_clk = spi_clk; sp->ctlr_clk = ctlr_clk; + sp->buffer = dmam_alloc_coherent(&pdev->dev, + MTK_NOR_BOUNCE_BUF_SIZE + MTK_NOR_DMA_ALIGN, + &sp->buffer_dma, GFP_KERNEL); + if (!sp->buffer) + return -ENOMEM; + + if ((uintptr_t)sp->buffer & MTK_NOR_DMA_ALIGN_MASK) { + dev_err(sp->dev, "misaligned allocation of internal buffer.\n"); + return -ENOMEM; + } irq = platform_get_irq_optional(pdev, 0); if (irq < 0) {