From patchwork Mon Sep 11 10:26:52 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Steffen X-Patchwork-Id: 9947043 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 1B0A8603F3 for ; Mon, 11 Sep 2017 10:27:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 06DD328B7C for ; Mon, 11 Sep 2017 10:27:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EFDD728B7F; Mon, 11 Sep 2017 10:27:54 +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=unavailable 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 9A51628B7C for ; Mon, 11 Sep 2017 10:27:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751076AbdIKK1k (ORCPT ); Mon, 11 Sep 2017 06:27:40 -0400 Received: from smtp2.infineon.com ([217.10.52.18]:42027 "EHLO smtp2.infineon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750986AbdIKK1j (ORCPT ); Mon, 11 Sep 2017 06:27:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infineon.com; i=@infineon.com; q=dns/txt; s=IFXMAIL; t=1505125659; x=1536661659; h=from:to:cc:subject:date:message-id:mime-version; bh=Qxx5LK/5Vqg2gs1AFxb1I1LLjgCbosN780MaW+nPDnc=; b=bodPKdT+OkwnRZCArci1DVlcQWaR4wHm0XXtgRpIBHcKKHhfHZHZ6uGD 3MEK2pHibjQtKyfrT9Fb2l9GnOKgClk+YxqDdCdl6gsA2QQpOJar7e1j1 M/N1yrXRUaNyYwdLHmO8RRBCufAWY54Tg0wAn6Zv794kT5DTEi5JErW4c 0=; 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; 11 Sep 2017 12:27:37 +0200 Received: from MUCSE606.infineon.com (mucse606.infineon.com [172.23.7.107]) by mucxv002.muc.infineon.com (Postfix) with ESMTPS; Mon, 11 Sep 2017 12:27:37 +0200 (CEST) Received: from MUCSE603.infineon.com (172.23.7.104) by MUCSE606.infineon.com (172.23.7.107) with Microsoft SMTP Server (TLS) id 15.0.1263.5; Mon, 11 Sep 2017 12:27:37 +0200 Received: from ABGN5CG4522MQD.eu.infineon.com (172.29.170.117) by MUCSE603.infineon.com (172.23.7.104) with Microsoft SMTP Server (TLS) id 15.0.1263.5; Mon, 11 Sep 2017 12:27:37 +0200 From: Alexander Steffen To: , CC: , , Alexander Steffen , Subject: [PATCH v4] tpm_tis_spi: Use DMA-safe memory for SPI transfers Date: Mon, 11 Sep 2017 12:26:52 +0200 Message-ID: <20170911102652.15356-1-Alexander.Steffen@infineon.com> X-Mailer: git-send-email 2.11.1.windows.1 MIME-Version: 1.0 X-Originating-IP: [172.29.170.117] 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 The buffers used as tx_buf/rx_buf in a SPI transfer need to be DMA-safe. This cannot be guaranteed for the buffers passed to tpm_tis_spi_read_bytes and tpm_tis_spi_write_bytes. Therefore, we need to use our own DMA-safe buffer and copy the data to/from it. The buffer needs to be allocated separately, to ensure that it is cacheline-aligned and not shared with other data, so that DMA can work correctly. Fixes: 0edbfea537d1 ("tpm/tpm_tis_spi: Add support for spi phy") Cc: stable@vger.kernel.org Signed-off-by: Alexander Steffen --- v2: - Updated commit message with more explanations. v3: - Split into two patches, one for making the buffers DMA-safe and another for using only a single buffer. v4: - Back to one patch, to fix conflicts with new const buffers. drivers/char/tpm/tpm_tis_spi.c | 45 +++++++++++++++++++++++++----------------- 1 file changed, 27 insertions(+), 18 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c index e49f5b9..8ab0bd8 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[4]; - u8 rx_buf[4]; + 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] = (in ? 0x80 : 0) | (transfer_len - 1); - phy->tx_buf[1] = 0xd4; - phy->tx_buf[2] = addr >> 8; - phy->tx_buf[3] = addr; + phy->iobuf[0] = (in ? 0x80 : 0) | (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; } @@ -112,8 +110,14 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, spi_xfer.cs_change = 0; spi_xfer.len = transfer_len; spi_xfer.delay_usecs = 5; - spi_xfer.tx_buf = out; - spi_xfer.rx_buf = in; + + if (in) { + spi_xfer.tx_buf = NULL; + } else if (out) { + spi_xfer.rx_buf = NULL; + memcpy(phy->iobuf, out, transfer_len); + out += transfer_len; + } spi_message_init(&m); spi_message_add_tail(&spi_xfer, &m); @@ -121,11 +125,12 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, if (ret < 0) goto exit; - len -= transfer_len; - if (in) + if (in) { + memcpy(in, phy->iobuf, transfer_len); in += transfer_len; - if (out) - out += transfer_len; + } + + len -= transfer_len; } exit: @@ -191,6 +196,10 @@ static int tpm_tis_spi_probe(struct spi_device *dev) phy->spi_device = dev; + 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, NULL); }