From patchwork Sat Sep 12 18:17:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Anderson X-Patchwork-Id: 292894 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F2CAC433E2 for ; Sat, 12 Sep 2020 18:18:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F11D72158C for ; Sat, 12 Sep 2020 18:18:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="cwvhRxfb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725910AbgILSSY (ORCPT ); Sat, 12 Sep 2020 14:18:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725877AbgILSST (ORCPT ); Sat, 12 Sep 2020 14:18:19 -0400 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6BCAC061757 for ; Sat, 12 Sep 2020 11:18:18 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id o20so9453450pfp.11 for ; Sat, 12 Sep 2020 11:18:18 -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:mime-version :content-transfer-encoding; bh=a1GTBXxKUvJxoon/aNt1MN6fmALohNRxcmfcvMYUVuI=; b=cwvhRxfbcTFj4svbdXDZ9jcAEMhYVMR7LZ4P87bq1El3TaxmfOrqur6oTokv//oGuR O6lBjAZZoASK01mJbAZUMKWC8cxKClvwn+gDUrgegq07Rhz3N7cIq0hUCJNbKT3N6xVs DZAooRgvRH8KK96ejVU7xL8oGc/eW70Ngbe6s= 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:mime-version :content-transfer-encoding; bh=a1GTBXxKUvJxoon/aNt1MN6fmALohNRxcmfcvMYUVuI=; b=KZ7RmoL5pZDO8EQaXksDyeUn88v+i+PULyIxN5YqfsB25mRf1cxPmZtpTBWFi+rhaQ WL7VaRw8asrQ9UZynMxRRNwKvtbJ2m6j658JQyoUqy1THePmrQCJ/upRZMR7tA6See2+ Pw/lRVpmJFuBeRVLsmDl/l9cICXY973W0Uapsq9jFL5rsMhv8wkYCSGlGQuXEJ9qUS8i MFAUfkqmtwTkbSblrWcL1VGP55JLcu4B5r2XgW8kjLGdU4JMnpHARlKdVyJcrofx+gbU ve/X1wJM7cB18e04CQPrxsTOAtWZgGbcAHVoPzhOX2pt7prWkm8LvpPMDBo9b2kip7Pz +AZw== X-Gm-Message-State: AOAM533KVoLwikvCsys0ImWMj9tgygJcDX8xmz0hcmSXIGYMHbAkPHHF OZZFjyt+PlzKnOl6GJ6Kn5gDOHf2Q3EMAg== X-Google-Smtp-Source: ABdhPJxwX4AccK3tYQzQmCHCIqpQZFNdVItS5jcKZcDzjfHI6EGkPeg1jTKnv2I6CfAhC/+Xma58Vw== X-Received: by 2002:aa7:80d3:: with SMTP id a19mr7177026pfn.102.1599934698016; Sat, 12 Sep 2020 11:18:18 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:1:42b0:34ff:fe3d:58e6]) by smtp.gmail.com with ESMTPSA id f6sm5858183pfq.82.2020.09.12.11.18.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 12 Sep 2020 11:18:17 -0700 (PDT) From: Douglas Anderson To: Mark Brown Cc: swboyd@chromium.org, Akash Asthana , Douglas Anderson , Andy Gross , Bjorn Andersson , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org Subject: [PATCH] spi: spi-geni-qcom: Don't wait to start 1st transfer if transmitting Date: Sat, 12 Sep 2020 11:17:25 -0700 Message-Id: <20200912111716.1.Ied5e843fad0d6b733a1fb8bcfb364dd2fa889eb3@changeid> X-Mailer: git-send-email 2.28.0.618.gf4bc123cb7-goog MIME-Version: 1.0 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org If we're sending bytes over SPI, we know the FIFO is empty at the start of the transfer. There's no reason to wait for the interrupt telling us to start--we can just start right away. Then if we transmit everything in one swell foop we don't even need to bother listening for TX interrupts. In a test of "flashrom -p ec -r /tmp/foo.bin" interrupts were reduced from ~30560 to ~29730, about a 3% savings. This patch looks bigger than it is because I moved a few functions rather than adding a forward declaration. The only actual change to geni_spi_handle_tx() was to make it return a bool indicating if there is more to tx. Signed-off-by: Douglas Anderson --- drivers/spi/spi-geni-qcom.c | 167 +++++++++++++++++++----------------- 1 file changed, 86 insertions(+), 81 deletions(-) diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c index 0dc3f4c55b0b..49c9eb870755 100644 --- a/drivers/spi/spi-geni-qcom.c +++ b/drivers/spi/spi-geni-qcom.c @@ -326,6 +326,88 @@ static int spi_geni_init(struct spi_geni_master *mas) return 0; } +static unsigned int geni_byte_per_fifo_word(struct spi_geni_master *mas) +{ + /* + * Calculate how many bytes we'll put in each FIFO word. If the + * transfer words don't pack cleanly into a FIFO word we'll just put + * one transfer word in each FIFO word. If they do pack we'll pack 'em. + */ + if (mas->fifo_width_bits % mas->cur_bits_per_word) + return roundup_pow_of_two(DIV_ROUND_UP(mas->cur_bits_per_word, + BITS_PER_BYTE)); + + return mas->fifo_width_bits / BITS_PER_BYTE; +} + +static bool geni_spi_handle_tx(struct spi_geni_master *mas) +{ + struct geni_se *se = &mas->se; + unsigned int max_bytes; + const u8 *tx_buf; + unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas); + unsigned int i = 0; + + max_bytes = (mas->tx_fifo_depth - mas->tx_wm) * bytes_per_fifo_word; + if (mas->tx_rem_bytes < max_bytes) + max_bytes = mas->tx_rem_bytes; + + tx_buf = mas->cur_xfer->tx_buf + mas->cur_xfer->len - mas->tx_rem_bytes; + while (i < max_bytes) { + unsigned int j; + unsigned int bytes_to_write; + u32 fifo_word = 0; + u8 *fifo_byte = (u8 *)&fifo_word; + + bytes_to_write = min(bytes_per_fifo_word, max_bytes - i); + for (j = 0; j < bytes_to_write; j++) + fifo_byte[j] = tx_buf[i++]; + iowrite32_rep(se->base + SE_GENI_TX_FIFOn, &fifo_word, 1); + } + mas->tx_rem_bytes -= max_bytes; + if (!mas->tx_rem_bytes) { + writel(0, se->base + SE_GENI_TX_WATERMARK_REG); + return false; + } + return true; +} + +static void geni_spi_handle_rx(struct spi_geni_master *mas) +{ + struct geni_se *se = &mas->se; + u32 rx_fifo_status; + unsigned int rx_bytes; + unsigned int rx_last_byte_valid; + u8 *rx_buf; + unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas); + unsigned int i = 0; + + rx_fifo_status = readl(se->base + SE_GENI_RX_FIFO_STATUS); + rx_bytes = (rx_fifo_status & RX_FIFO_WC_MSK) * bytes_per_fifo_word; + if (rx_fifo_status & RX_LAST) { + rx_last_byte_valid = rx_fifo_status & RX_LAST_BYTE_VALID_MSK; + rx_last_byte_valid >>= RX_LAST_BYTE_VALID_SHFT; + if (rx_last_byte_valid && rx_last_byte_valid < 4) + rx_bytes -= bytes_per_fifo_word - rx_last_byte_valid; + } + if (mas->rx_rem_bytes < rx_bytes) + rx_bytes = mas->rx_rem_bytes; + + rx_buf = mas->cur_xfer->rx_buf + mas->cur_xfer->len - mas->rx_rem_bytes; + while (i < rx_bytes) { + u32 fifo_word = 0; + u8 *fifo_byte = (u8 *)&fifo_word; + unsigned int bytes_to_read; + unsigned int j; + + bytes_to_read = min(bytes_per_fifo_word, rx_bytes - i); + ioread32_rep(se->base + SE_GENI_RX_FIFOn, &fifo_word, 1); + for (j = 0; j < bytes_to_read; j++) + rx_buf[i++] = fifo_byte[j]; + } + mas->rx_rem_bytes -= rx_bytes; +} + static void setup_fifo_xfer(struct spi_transfer *xfer, struct spi_geni_master *mas, u16 mode, struct spi_master *spi) @@ -398,8 +480,10 @@ static void setup_fifo_xfer(struct spi_transfer *xfer, * setting up GENI SE engine, as driver starts data transfer * for the watermark interrupt. */ - if (m_cmd & SPI_TX_ONLY) - writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG); + if (m_cmd & SPI_TX_ONLY) { + if (geni_spi_handle_tx(mas)) + writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG); + } spin_unlock_irq(&mas->lock); } @@ -417,85 +501,6 @@ static int spi_geni_transfer_one(struct spi_master *spi, return 1; } -static unsigned int geni_byte_per_fifo_word(struct spi_geni_master *mas) -{ - /* - * Calculate how many bytes we'll put in each FIFO word. If the - * transfer words don't pack cleanly into a FIFO word we'll just put - * one transfer word in each FIFO word. If they do pack we'll pack 'em. - */ - if (mas->fifo_width_bits % mas->cur_bits_per_word) - return roundup_pow_of_two(DIV_ROUND_UP(mas->cur_bits_per_word, - BITS_PER_BYTE)); - - return mas->fifo_width_bits / BITS_PER_BYTE; -} - -static void geni_spi_handle_tx(struct spi_geni_master *mas) -{ - struct geni_se *se = &mas->se; - unsigned int max_bytes; - const u8 *tx_buf; - unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas); - unsigned int i = 0; - - max_bytes = (mas->tx_fifo_depth - mas->tx_wm) * bytes_per_fifo_word; - if (mas->tx_rem_bytes < max_bytes) - max_bytes = mas->tx_rem_bytes; - - tx_buf = mas->cur_xfer->tx_buf + mas->cur_xfer->len - mas->tx_rem_bytes; - while (i < max_bytes) { - unsigned int j; - unsigned int bytes_to_write; - u32 fifo_word = 0; - u8 *fifo_byte = (u8 *)&fifo_word; - - bytes_to_write = min(bytes_per_fifo_word, max_bytes - i); - for (j = 0; j < bytes_to_write; j++) - fifo_byte[j] = tx_buf[i++]; - iowrite32_rep(se->base + SE_GENI_TX_FIFOn, &fifo_word, 1); - } - mas->tx_rem_bytes -= max_bytes; - if (!mas->tx_rem_bytes) - writel(0, se->base + SE_GENI_TX_WATERMARK_REG); -} - -static void geni_spi_handle_rx(struct spi_geni_master *mas) -{ - struct geni_se *se = &mas->se; - u32 rx_fifo_status; - unsigned int rx_bytes; - unsigned int rx_last_byte_valid; - u8 *rx_buf; - unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas); - unsigned int i = 0; - - rx_fifo_status = readl(se->base + SE_GENI_RX_FIFO_STATUS); - rx_bytes = (rx_fifo_status & RX_FIFO_WC_MSK) * bytes_per_fifo_word; - if (rx_fifo_status & RX_LAST) { - rx_last_byte_valid = rx_fifo_status & RX_LAST_BYTE_VALID_MSK; - rx_last_byte_valid >>= RX_LAST_BYTE_VALID_SHFT; - if (rx_last_byte_valid && rx_last_byte_valid < 4) - rx_bytes -= bytes_per_fifo_word - rx_last_byte_valid; - } - if (mas->rx_rem_bytes < rx_bytes) - rx_bytes = mas->rx_rem_bytes; - - rx_buf = mas->cur_xfer->rx_buf + mas->cur_xfer->len - mas->rx_rem_bytes; - while (i < rx_bytes) { - u32 fifo_word = 0; - u8 *fifo_byte = (u8 *)&fifo_word; - unsigned int bytes_to_read; - unsigned int j; - - bytes_to_read = min(bytes_per_fifo_word, rx_bytes - i); - ioread32_rep(se->base + SE_GENI_RX_FIFOn, &fifo_word, 1); - for (j = 0; j < bytes_to_read; j++) - rx_buf[i++] = fifo_byte[j]; - } - mas->rx_rem_bytes -= rx_bytes; -} - static irqreturn_t geni_spi_isr(int irq, void *data) { struct spi_master *spi = data;