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: [email protected]
Signed-off-by: Alexander Steffen <[email protected]>
---
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
------------------------------------------------------------------------------
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