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: NPeter Huewe <peter.huewe@infineon.com>
Signed-off-by: NAlexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

To avoid code duplication between the old tpm_tis and the new and future
native tcg tis driver(ie: spi, i2c...), the tpm_tis driver was reworked,
so that all common logic is extracted and can be reused from all drivers.

The core methods can also be used from other TIS like drivers.

itpm workaround is now managed with a specific tis flag
TPM_TIS_ITPM_POSSIBLE.

This commit is based on the initial work by Peter Huewe.
Signed-off-by: NPeter Huewe <peter.huewe@infineon.com>
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Add missing vendor to vendor-prefix.txt.

Trusted Computing Group design common specifications for
TPM (Trusted Platform Module) vendors.
TCG designates a TPM answering to a public specification.

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

Cc: devicetree@vger.kernel.org
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Acked-by: NRob Herring <robh@kernel.org>
Acked-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Add missing vendor to vendor-prefix.txt

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

Cc: devicetree@vger.kernel.org
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Acked-by: NRob Herring <robh@kernel.org>
Acked-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

This splits tpm_tis in a high-level protocol part and a low-level interface
for the actual TPM communication. The low-level interface can then be
implemented by additional drivers to provide access to TPMs using other
mechanisms, for example native I2C or SPI transfers, while still reusing
the same TIS protocol implementation.

Though the ioread/iowrite calls cannot fail, other implementations of this
interface might want to return error codes if their communication fails.

This follows the usual pattern of negative values representing errors and
zero representing success. Positive values are not used (yet).

Errors are passed back to the caller if possible. If the interface of a
function does not allow that, it tries to do the most sensible thing it
can, but this might also mean ignoring the error in this instance.

This commit is based on the initial work by Peter Huewe.
Signed-off-by: NAlexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Split priv_data structure in common and phy specific structures. This will
allow in future patches to reuse the same tis logic on top of new phy such
as spi and i2c. Ultimately, other drivers may reuse this tis logic.
(e.g: st33zp24...)

iobase field is specific to TPM addressed on 0xFED4xxxx on LPC/SPI bus.

This commit is based on the initial work by Peter Huewe.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Add missing include guards in tpm.h
Signed-off-by: NPeter Huewe <peter.huewe@infineon.com>
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Fix the suspend regression due to the wrong way of retrieving the
chip structure. The suspend functions are attached to the hardware
device, not the chip and thus must rely on drvdata.

Fixes: e89f8b1ade9cc1a ("tpm: Remove all uses of drvdata from the TPM Core")
Reported-by: NJeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NJeremiah Mahler <jmmahler@gmail.com>
Acked-by: NJarkko Sakkinen <jarkko.sakkine@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkine@linux.intel.com>

Fixes: 28157164b056 ("tpm: Remove useless priv field in struct tpm_vendor_specific")
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

The newly added vtpmx driver fails to build if CONFIG_ANON_INODES
is disabled:

drivers/char/built-in.o: In function `vtpmx_fops_ioctl':
(.text+0x97f8): undefined reference to `anon_inode_getfile'

This adds a Kconfig 'select' statement to ensure it's always there
when we need it.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: 794c38e01358 ("tpm: Proxy driver for supporting multiple emulated TPMs")
Acked-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Acked-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

The devm for the IRQ was placed on the chip, not the pdev. This can
cause the irq to be still callable after the pdev has been cleaned up
(eg priv kfree'd).

Found by CONFIG_DEBUG_SHIRQ=y
Reported-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Fixes: 233a065e0cd0 ("tpm: Get rid of chip->pdev")
Signed-off-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Add documentation for the tpm_vtpm device driver that implements
support for providing TPM functionality to Linux containers.

Parts of this documentation were recycled from the Xen vTPM
device driver documentation.

Update the documentation for the ioctl numbers.
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

CC: linux-kernel@vger.kernel.org
CC: linux-doc@vger.kernel.org
CC: linux-api@vger.kernel.org
Tested-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

This patch implements a proxy driver for supporting multiple emulated TPMs
in a system.

The driver implements a device /dev/vtpmx that is used to created
a client device pair /dev/tpmX (e.g., /dev/tpm10) and a server side that
is accessed using a file descriptor returned by an ioctl.
The device /dev/tpmX is the usual TPM device created by the core TPM
driver. Applications or kernel subsystems can send TPM commands to it
and the corresponding server-side file descriptor receives these
commands and delivers them to an emulated TPM.

The driver retrievs the TPM 1.2 durations and timeouts. Since this requires
the startup of the TPM, we send a startup for TPM 1.2 as well as TPM 2.
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>

CC: linux-kernel@vger.kernel.org
CC: linux-doc@vger.kernel.org
CC: linux-api@vger.kernel.org
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Introduce TPM_CHIP_FLAG_VIRTUAL to be used when the chip device has no
parent device.

Prevent sysfs entries requiring a parent device from being created.
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

The final thing preventing this was the way the sysfs files were
attached to the pdev. Follow the approach developed for ppi and move
the sysfs files to the chip->dev with symlinks from the pdev
for compatibility. Everything in the core now sanely uses container_of
to get the chip.
Signed-off-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Remove useless priv field in struct tpm_vendor_specific and take benefit
of chip->dev.driver_data.  As priv is the latest field available in
struct tpm_vendor_specific, remove any reference to that structure.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Move tpm_vendor_specific data related to TCG PTP specification to tpm_chip.

Move all fields directly linked with well known TCG concepts and used in
TPM drivers (tpm_i2c_atmel, tpm_i2c_infineon, tpm_i2c_nuvoton, tpm_tis
and xen-tpmfront) as well as in TPM core files (tpm-sysfs, tpm-interface
and tpm2-cmd) in tpm_chip.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Dropped the field 'locality' from struct tpm_vendor_specific migrated it to
the private structures of st33zp24, tpm_i2c_infineon and tpm_tis.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Dropped the field 'read_queue' from struct tpm_vendor_specific and make it
available to the various private structures in the drivers.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Dropped the field 'irq' from struct tpm_vendor_specific and make it
available to the various private structures in the drivers using irqs.

A dedicated flag TPM_CHIP_FLAG_IRQ is added for the upper layers.

In st33zp24, struct st33zp24_dev declaration is moved to st33zp24.h in
order to make accessible irq from other phy's(i2c, spi).

In tpm_i2c_nuvoton, chip->vendor.priv is not directly allocated. We can
access irq field from priv_data in a cleaner way.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Dropped the field 'iobase' from struct tpm_vendor_specific and migrated
it to the private structures of tpm_atmel and tpm_tis.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Dropped list from struct tpm_vendor_specific as it is not used in any
place.

It is initialized in tpm_i2c_infineon but not used at all in the code.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Removed the field because it is not used for anything.
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>

Dropped the field 'base' from struct tpm_vendor_specific and migrated
it to the private structures of tpm_atmel and tpm_nsc.
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>

Dropped manufacturer_id from struct tpm_vendor_specific and redeclared
it in the private struct priv_data that tpm_tis uses because the field
is only used tpm_tis.
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>

Introduced a private struct tpm_atmel_priv that contains the variables
have_region and region_size that were previously located in struct
tpm_vendor_specific. These fields were only used by tpm_atmel.
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>

Drop field int_queue from tpm_vendor_specific as it is used only by
tpm_tis. Probably all of the fields should be eventually dropped and
moved to the private structures of different drivers but it is better to
do this one step at a time in order not to break anything.
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>

Fixes: 20e0152393b41 ("tpm: fix crash in tpm_tis deinitialization")
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reported-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-By: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>

On my Lenovo x250 the following situation occurs:

[18697.813871] tpm_crb MSFT0101:00: can't request region for resource
[mem 0xacdff080-0xacdfffff]

The mapping of the control area overlaps the mapping of the command
buffer. The control area is mapped over page, which is not right. It
should mapped over sizeof(struct crb_control_area).

Fixing this issue unmasks another issue. Command and response buffers
can overlap and they do interleave on this machine. According to the PTP
specification the overlapping means that they are mapped to the same
buffer.

The commit has been also on a Haswell NUC where things worked before
applying this fix so that the both code paths for response buffer
initialization are tested.

Cc: stable@vger.kernel.org
Fixes: 1bd047be ("tpm_crb: Use devm_ioremap_resource")
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>

We can get rid of tpm_reg variable in get_burstcount.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

When st33zp24_spi_acpi_request_resources() gets called we
already know that the entries in ->acpi_match_table have matched ACPI ID
of the device.
In addition spi_device pointer cannot be NULL in any case (otherwise I2C
core would not call ->probe() for the driver in the first place).

Drop the two useless checks from the driver.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

When st33zp24_i2c_acpi_request_resources() gets called we
already know that the entries in ->acpi_match_table have matched ACPI ID
of the device.
In addition I2C client pointer cannot be NULL in any case (otherwise I2C
core would not call ->probe() for the driver in the first place).

Drop the two useless checks from the driver.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

The iomem resource is needed only temporarily so it is better to pass
it on instead of storing it permanently. Named the variable as io_res
so that the code better documents itself.
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: NStefan Berger <stefanb@linux.vnet.ibm.com>

rmmod crashes the driver because tpm_chip_unregister() already sets ops
to NULL. This commit fixes the issue by moving tpm2_shutdown() to
tpm_chip_unregister(). This commit is also cleanup because it removes
duplicate code from tpm_crb and tpm_tis to the core.

Fixes: 4d3eac5e156a ("tpm: Provide strong locking for device removal")
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>

Created a local variable pointing to the INT_ENABLE_x register. The
expression clearing INT_ENABLE_x.globalIntEnable is unreadable and
hard to modify without surpassing the 80 char boundary.
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NChristophe Ricard <christophe-h.ricard@st.com>

A cleanup patch changed the prototype of the regular tpm_bios_log_setup
function, but not that of the stub that is used when the TPM is disabled,
causing a harmless build warning:

drivers/char/tpm/tpm-chip.c: In function 'tpm1_chip_register':
drivers/char/tpm/tpm-chip.c:287:38: error: passing argument 1 of 'tpm_bios_log_setup' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
  chip->bios_dir = tpm_bios_log_setup(dev_name(&chip->dev));
In file included from ../drivers/char/tpm/tpm-chip.c:30:0:
../drivers/char/tpm/tpm_eventlog.h:83:31: note: expected 'char *' but argument is of type 'const char *'
 static inline struct dentry **tpm_bios_log_setup(char *name)

This changes the stub function to match the normal prototype,
avoiding that warning.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: aca8db8088c3 ("tpm: Get rid of devname")
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Replace the device number bitmap with IDR. Extend the number of devices we
can create to 64k.
Since an IDR allows us to associate a pointer with an ID, we use this now
to rewrite tpm_chip_find_get() to simply look up the chip pointer by the
given device ID.

Protect the IDR calls with a mutex.
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

tpm_chip_alloc becomes a typical subsystem allocate call.
Signed-off-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Now that the tpm core has strong locking around 'ops' it is possible
to remove a TPM driver, module and all, even while user space still
has things like /dev/tpmX open. For consistency and simplicity, drop
the module locking entirely.
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Add a read/write semaphore around the ops function pointers so
ops can be set to null when the driver un-registers.

Previously the tpm core expected module locking to be enough to
ensure that tpm_unregister could not be called during certain times,
however that hasn't been sufficient for a long time.

Introduce a read/write semaphore around 'ops' so the core can set
it to null when unregistering. This provides a strong fence around
the driver callbacks, guaranteeing to the driver that no callbacks
are running or will run again.

For now the ops_lock is placed very high in the call stack, it could
be pushed down and made more granular in future if necessary.
Signed-off-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>