Re: [PATCH v9 0/5] tpm: Command duration logging and chip-specific override

[Jason Gunthorpe <jgunthorpe@obsidianresearch.com>]

On Wed, Jul 13, 2016 at 09:44:05AM -0700, Ed Swierk wrote:
> On Wed, Jul 13, 2016 at 9:19 AM, Ed Swierk <eswierk@skyportsystems.com> wrote:
> > v9: Include command duration in existing error messages rather than
> > logging an extra debug message. Rebase onto Jarkko's tree.
> 
> Incidentally, with Jarkko's tree the tpm_tis module refuses to
> initialize (with or without force=1):
> 
> tpm_tis 00:03: can't request region for resource [mem 0xfed40000-0xfed44fff]
> tpm_tis: probe of 00:03 failed with error -16
>
> The memory region is not marked reserved by the BIOS:
> fed30000-fedfffff : RAM buffer

I think your bios is broken?

A working BIOS will look like this:

 $ cat /proc/iomem  | grep -i fed400
 fed40000-fed44fff : pnp 00:00

It sets aside the struct resource during pnp:

 [    0.097318] pnp: PnP ACPI init
 [    0.097366] system 00:00: [mem 0xfed40000-0xfed44fff] has been reserved

What did your system do?

You should see prints like this:

                printk(KERN_DEBUG
                       "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n",
                       start, end);

Which only happen if E820_RAM is set, which is certainly not right for
TPM memory.

I don't know what kernel convention is to handle these sorts of
defects?

Is the use of the memmap kernel command line an appropriate work
around?

Jason