[PATCH v6 0/2] tpm: add support for nonblocking operation

On Mon, Sep 10, 2018 at 10:18:22AM -0700, Tadeusz Struk wrote:

The TCG SAPI specification [1] defines a set of functions, which allow
applications to use the TPM device in either blocking or non-blocking fashion.
Each command defined by the specification has a corresponding
Tss2_Sys_<COMMAND>_Prepare() and Tss2_Sys_<COMMAND>_Complete() call, which
together with Tss2_Sys_ExecuteAsync() is designed to allow asynchronous
mode of operation. Currently the TPM driver supports only blocking calls,
which doesn't allow asynchronous IO operations.
This patch changes it and adds support for nonblocking write and a new poll
function to enable applications, which want to take advantage of this feature.
The new functionality can be tested using standard TPM tools implemented
in [2], together with modified TCTI from [3], and an example application
by Philip Tricca [4]. Here is a short description from Philip:

"The example application `glib-tss2-event` uses a glib main event loop
to create an RSA 2048 primary key in the TPM2 NULL hierarchy while
using a glib timer event to time the operation. A GSource object is
used to generate an event when the FD underlying the tss2 function
call has data ready. While the application waits for an event indicating
that the CreatePrimary operation is complete, it counts timer events
that occur every 100ms. Once the CreatePrimary operation completes the
number of timer events that occurred is used to make a rough calculation
of the elapsed time. This value is then printed to the console.
This takes ~300 lines of C code and requires no management or
synchronization of threads. The glib GMainContext is "just a poll()
loop" according to the glib documentation here:

https://developer.gnome.org/programming-guidelines/stable/main-contexts.html.en

and so supporting 'poll' is the easiest way to integrate with glib /
gtk+. This is true of any other event system that relies on 'poll'
instead of worker threads."

[1] https://trustedcomputinggroup.org/wp-content/uploads/TSS_SAPI_Version-1.1_Revision-22_review_030918.pdf
[2] https://github.com/tpm2-software/tpm2-tools
[3] https://github.com/tstruk/tpm2-tss/tree/async
[4] https://github.com/flihp/glib-tss2-async-example

I tried to test this but I get 404 from https://github.com/tstruk/tpm2-tss/tree/async

/Jarkko