From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Steffen Subject: [PATCH] tpm_tis_spi: Use DMA-safe memory for SPI transfers Date: Tue, 4 Jul 2017 15:56:09 +0200 Message-ID: <20170704135609.5064-1-Alexander.Steffen@infineon.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Sender: stable-owner@vger.kernel.org To: tpmdd-devel@lists.sourceforge.net Cc: Alexander Steffen , stable@vger.kernel.org List-Id: tpmdd-devel@lists.sourceforge.net 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. Fixes: 0edbfea537d1 ("tpm/tpm_tis_spi: Add support for spi phy") Cc: stable@vger.kernel.org Signed-off-by: Alexander Steffen --- drivers/char/tpm/tpm_tis_spi.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c index 88fe72a..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[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] = 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; } @@ -115,10 +113,9 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, if (direction) { spi_xfer.tx_buf = NULL; - spi_xfer.rx_buf = buffer; } else { - spi_xfer.tx_buf = buffer; spi_xfer.rx_buf = NULL; + memcpy(phy->iobuf, buffer, transfer_len); } spi_message_init(&m); @@ -127,6 +124,9 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, if (ret < 0) goto exit; + if (direction) + memcpy(buffer, phy->iobuf, transfer_len); + len -= transfer_len; buffer += transfer_len; } @@ -194,6 +194,10 @@ 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); } -- 2.7.4