This is a note to let you know that I've just added the patch titled
tpm_tis_spi: Use DMA-safe memory for SPI transfers
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tpm_tis_spi-use-dma-safe-memory-for-spi-transfers.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6b3a13173f23e798e1ba213dd4a2c065a3b8d751 Mon Sep 17 00:00:00 2001
From: Alexander Steffen <Alexander.Steffen@xxxxxxxxxxxx>
Date: Mon, 11 Sep 2017 12:26:52 +0200
Subject: tpm_tis_spi: Use DMA-safe memory for SPI transfers
From: Alexander Steffen <Alexander.Steffen@xxxxxxxxxxxx>
commit 6b3a13173f23e798e1ba213dd4a2c065a3b8d751 upstream.
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@xxxxxxxxxxxxxxx
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: Alexander Steffen <Alexander.Steffen@xxxxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm_tis_spi.c | 45 ++++++++++++++++++++++++-----------------
1 file changed, 27 insertions(+), 18 deletions(-)
--- 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 t
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 t
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 t
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 t
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 t
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_
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);
}
Patches currently in stable-queue which might be from Alexander.Steffen@xxxxxxxxxxxx are
queue-4.14/tpm_tis_spi-use-dma-safe-memory-for-spi-transfers.patch