From patchwork Thu Aug 31 16:58:19 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Steffen X-Patchwork-Id: 9932519 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 3991960362 for ; Thu, 31 Aug 2017 16:58:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 29D2728994 for ; Thu, 31 Aug 2017 16:58:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1C1E428A14; Thu, 31 Aug 2017 16:58:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B342728994 for ; Thu, 31 Aug 2017 16:58:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751827AbdHaQ6n (ORCPT ); Thu, 31 Aug 2017 12:58:43 -0400 Received: from smtp2.infineon.com ([217.10.52.18]:20268 "EHLO smtp2.infineon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751834AbdHaQ6k (ORCPT ); Thu, 31 Aug 2017 12:58:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infineon.com; i=@infineon.com; q=dns/txt; s=IFXMAIL; t=1504198719; x=1535734719; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=z/9t6Epliv0YlINrRs1KWP+A8Tcn24DXYtdUXGFrDdo=; b=NgRUVDQFifkkeUpeHuvvZywQnplW6FZwSgMlcUxGQru2JkR70anbygwC lsocRrDIDb1vlYyh5MtvhIqZVy9+tcJKi8yFlhBFJfYHJbYA5lELNWWa9 8U6HGD0GFnK85hFimu2V8rqEFZbzmJjR7T63c19DJSxBhgF2vjfuvJuuU M=; X-SBRS: None Received: from unknown (HELO mucxv002.muc.infineon.com) ([172.23.11.17]) by smtp2.infineon.com with ESMTP/TLS/AES256-GCM-SHA384; 31 Aug 2017 18:58:38 +0200 Received: from MUCSE608.infineon.com (mucse608.infineon.com [172.23.7.109]) by mucxv002.muc.infineon.com (Postfix) with ESMTPS; Thu, 31 Aug 2017 18:58:38 +0200 (CEST) Received: from MUCSE603.infineon.com (172.23.7.104) by MUCSE608.infineon.com (172.23.7.109) with Microsoft SMTP Server (TLS) id 15.0.1263.5; Thu, 31 Aug 2017 18:58:38 +0200 Received: from ABGN5CG4522MQD.eu.infineon.com (172.29.170.103) by MUCSE603.infineon.com (172.23.7.104) with Microsoft SMTP Server (TLS) id 15.0.1263.5; Thu, 31 Aug 2017 18:58:37 +0200 From: Alexander Steffen To: , , CC: , , Alexander Steffen Subject: [PATCH RESEND v3 2/2] tpm_tis_spi: Use a single buffer for SPI transfers Date: Thu, 31 Aug 2017 18:58:19 +0200 Message-ID: <20170831165819.13544-3-Alexander.Steffen@infineon.com> X-Mailer: git-send-email 2.11.1.windows.1 In-Reply-To: <20170831165819.13544-1-Alexander.Steffen@infineon.com> References: <20170831165819.13544-1-Alexander.Steffen@infineon.com> MIME-Version: 1.0 X-Originating-IP: [172.29.170.103] X-ClientProxiedBy: MUCSE601.infineon.com (172.23.7.102) To MUCSE603.infineon.com (172.23.7.104) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP A single buffer is sufficient for both tx and rx, since bytes that have already been sent are not used anymore and can safely be overwritten with the received bytes. Signed-off-by: Alexander Steffen Reviewed-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_tis_spi.c | 34 ++++++++++++++-------------------- 1 file changed, 14 insertions(+), 20 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c index 05ce841..5321245 100644 --- a/drivers/char/tpm/tpm_tis_spi.c +++ b/drivers/char/tpm/tpm_tis_spi.c @@ -46,9 +46,7 @@ struct tpm_tis_spi_phy { struct tpm_tis_data priv; struct spi_device *spi_device; - - u8 *tx_buf; - u8 *rx_buf; + u8 *iobuf; }; static inline struct tpm_tis_spi_phy *to_tpm_tis_spi_phy(struct tpm_tis_data *data) @@ -71,14 +69,14 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, while (len) { transfer_len = min_t(u16, len, MAX_SPI_FRAMESIZE); - phy->tx_buf[0] = direction | (transfer_len - 1); - phy->tx_buf[1] = 0xd4; - phy->tx_buf[2] = addr >> 8; - phy->tx_buf[3] = addr; + phy->iobuf[0] = direction | (transfer_len - 1); + phy->iobuf[1] = 0xd4; + phy->iobuf[2] = addr >> 8; + phy->iobuf[3] = addr; memset(&spi_xfer, 0, sizeof(spi_xfer)); - spi_xfer.tx_buf = phy->tx_buf; - spi_xfer.rx_buf = phy->rx_buf; + spi_xfer.tx_buf = phy->iobuf; + spi_xfer.rx_buf = phy->iobuf; spi_xfer.len = 4; spi_xfer.cs_change = 1; @@ -88,9 +86,9 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, if (ret < 0) goto exit; - if ((phy->rx_buf[3] & 0x01) == 0) { + if ((phy->iobuf[3] & 0x01) == 0) { // handle SPI wait states - phy->tx_buf[0] = 0; + phy->iobuf[0] = 0; for (i = 0; i < TPM_RETRY; i++) { spi_xfer.len = 1; @@ -99,7 +97,7 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, ret = spi_sync_locked(phy->spi_device, &m); if (ret < 0) goto exit; - if (phy->rx_buf[0] & 0x01) + if (phy->iobuf[0] & 0x01) break; } @@ -117,7 +115,7 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, spi_xfer.tx_buf = NULL; } else { spi_xfer.rx_buf = NULL; - memcpy(phy->tx_buf, buffer, transfer_len); + memcpy(phy->iobuf, buffer, transfer_len); } spi_message_init(&m); @@ -127,7 +125,7 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, goto exit; if (direction) - memcpy(buffer, phy->rx_buf, transfer_len); + memcpy(buffer, phy->iobuf, transfer_len); len -= transfer_len; buffer += transfer_len; @@ -196,12 +194,8 @@ static int tpm_tis_spi_probe(struct spi_device *dev) phy->spi_device = dev; - phy->tx_buf = devm_kmalloc(&dev->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL); - if (!phy->tx_buf) - return -ENOMEM; - - phy->rx_buf = devm_kmalloc(&dev->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL); - if (!phy->rx_buf) + phy->iobuf = devm_kmalloc(&dev->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL); + if (!phy->iobuf) return -ENOMEM; return tpm_tis_core_init(&dev->dev, &phy->priv, -1, &tpm_spi_phy_ops,