Commit Graph

8 Commits

Author SHA1 Message Date
Alexander Steffen eb75717b18 tpm_tis_spi: Use DMA-safe memory for SPI transfers
commit 6b3a13173f 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: 0edbfea537 ("tpm/tpm_tis_spi: Add support for spi phy")
Cc: stable@vger.kernel.org
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-11 16:21:27 +01:00
Arnd Bergmann e6b9e04f57 tpm: constify transmit data pointers
commit c37fbc09bd upstream.

Making cmd_getticks 'const' introduced a couple of harmless warnings:

drivers/char/tpm/tpm_tis_core.c: In function 'probe_itpm':
drivers/char/tpm/tpm_tis_core.c:469:31: error: passing argument 2 of 'tpm_tis_send_data' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
  rc = tpm_tis_send_data(chip, cmd_getticks, len);
drivers/char/tpm/tpm_tis_core.c:477:31: error: passing argument 2 of 'tpm_tis_send_data' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
  rc = tpm_tis_send_data(chip, cmd_getticks, len);
drivers/char/tpm/tpm_tis_core.c:255:12: note: expected 'u8 * {aka unsigned char *}' but argument is of type 'const u8 * {aka const unsigned char *}'
 static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)

This changes the related functions to all take 'const' pointers
so that gcc can see this as being correct. I had to slightly
modify the logic around tpm_tis_spi_transfer() for this to work
without introducing ugly casts.

Cc: stable@vger.kernel.org
Fixes: 5e35bd8e06b9 ("tpm_tis: make array cmd_getticks static const to shink object code size")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-11 16:21:27 +01:00
Peter Huewe 568ea0dcc2 tpm_tis_spi: Add small delay after last transfer
commit 5cc0101d1f upstream.

Testing the implementation with a Raspberry Pi 2 showed that under some
circumstances its SPI master erroneously releases the CS line before the
transfer is complete, i.e. before the end of the last clock. In this case
the TPM ignores the transfer and misses for example the GO command. The
driver is unable to detect this communication problem and will wait for a
command response that is never going to arrive, timing out eventually.

As a workaround, the small delay ensures that the CS line is held long
enough, even with a faulty SPI master. Other SPI masters are not affected,
except for a negligible performance penalty.

Fixes: 0edbfea537 ("tpm/tpm_tis_spi: Add support for spi phy")
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Peter Huewe <peter.huewe@infineon.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Benoit Houyere <benoit.houyere@st.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 15:44:32 +02:00
Peter Huewe c4b3779c97 tpm_tis_spi: Remove limitation of transfers to MAX_SPI_FRAMESIZE bytes
commit 591e48c26c upstream.

Limiting transfers to MAX_SPI_FRAMESIZE was not expected by the upper
layers, as tpm_tis has no such limitation. Add a loop to hide that
limitation.

v2: Moved scope of spi_message to the top as requested by Jarkko
Fixes: 0edbfea537 ("tpm/tpm_tis_spi: Add support for spi phy")
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Peter Huewe <peter.huewe@infineon.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Benoit Houyere <benoit.houyere@st.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 15:44:31 +02:00
Peter Huewe d513cf24e2 tpm_tis_spi: Check correct byte for wait state indicator
commit e110cc69dc upstream.

Wait states are signaled in the last byte received from the TPM in
response to the header, not the first byte. Check rx_buf[3] instead of
rx_buf[0].

Fixes: 0edbfea537 ("tpm/tpm_tis_spi: Add support for spi phy")
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Peter Huewe <peter.huewe@infineon.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Benoit Houyere <benoit.houyere@st.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 15:44:31 +02:00
Peter Huewe daa432c1a6 tpm_tis_spi: Abort transfer when too many wait states are signaled
commit 975094ddc3 upstream.

Abort the transfer with ETIMEDOUT when the TPM signals more than
TPM_RETRY wait states. Continuing with the transfer in this state
will only lead to arbitrary failures in other parts of the code.

Fixes: 0edbfea537 ("tpm/tpm_tis_spi: Add support for spi phy")
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Peter Huewe <peter.huewe@infineon.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Benoit Houyere <benoit.houyere@st.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 15:44:31 +02:00
Peter Huewe aad1e5c81c tpm_tis_spi: Use single function to transfer data
commit f848f2143a upstream.

The algorithm for sending data to the TPM is mostly identical to the
algorithm for receiving data from the TPM, so a single function is
sufficient to handle both cases.

This is a prequisite for all the other fixes, so we don't have to fix
everything twice (send/receive)

v2: u16 instead of u8 for the length.
Fixes: 0edbfea537 ("tpm/tpm_tis_spi: Add support for spi phy")
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Peter Huewe <peter.huewe@infineon.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Benoit Houyere <benoit.houyere@st.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 15:44:31 +02:00
Christophe Ricard 0edbfea537 tpm/tpm_tis_spi: Add support for spi phy
Spi protocol standardized by the TCG is now supported by most of TPM
vendors.

It supports SPI Bit Protocol as describe in the TCG PTP
specification (chapter 6.4.6 SPI Bit Protocol).

Irq mode is not supported.

This commit is based on the initial work by Peter Huewe.

Signed-off-by: Peter Huewe <peter.huewe@infineon.com>
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2016-06-25 17:28:57 +03:00