Sat, Mar 24, 2018 at 11:56:33AM CET, rahul.lakkireddy@chelsio.com wrote:

Add a new module crashdd that exports the /sys/kernel/crashdd/
directory in second kernel, containing collected hardware/firmware
dumps.

The sequence of actions done by device drivers to append their device
specific hardware/firmware logs to /sys/kernel/crashdd/ directory are
as follows:

1. During probe (before hardware is initialized), device drivers
register to the crashdd module (via crashdd_add_dump()), with
callback function, along with buffer size and log name needed for
firmware/hardware log collection.

2. Crashdd creates a driver's directory under
/sys/kernel/crashdd/<driver>. Then, it allocates the buffer with

This smells. I need to identify the exact ASIC instance that produced
the dump. To identify by driver name does not help me if I have multiple
instances of the same driver. This looks wrong to me. This looks like
a job for devlink where you have 1 devlink instance per 1 ASIC instance.

Please see:
http://patchwork.ozlabs.org/project/netdev/list/?series=36524

I bevieve that the solution in the patchset could be used for
your usecase too.

requested size and invokes the device driver's registered callback
function.

3. Device driver collects all hardware/firmware logs into the buffer
and returns control back to crashdd.

4. Crashdd exposes the buffer as a binary file via
/sys/kernel/crashdd/<driver>/<dump_file>.