On Mon, Jan 02, 2017 at 02:01:01PM -0700, Jason Gunthorpe wrote: > On Mon, Jan 02, 2017 at 03:22:07PM +0200, Jarkko Sakkinen wrote: > > Since there is only one thread using TPM chip at a time to transmit data > > we can migrate struct tpm_buf to struct tpm_chip. This makes the use of > > it more fail safe as the buffer is allocated from heap when the device > > is created and not for every transaction. > > Eh? What? I don't think that is the case.. > > We don't serialize until we hit tramsit_cmd at which point the buffer > is already being used and cannot be shared between threads.
There is a regression in the patch. All functions that use 'tr_buf' should take tpm_mutex first and use TPM_TRANSMIT_UNLOCKED. There's also a similar regression in TPM space patch that I have to correct. > Why would the resource manager need a single global tpm buffer? That > seems like a big regression from where we have been going. I don't > think this is a good idea to go down this road. What? 'tr_buf' is not specifically for resource manager. This commit makes creating TPM commands more fail-safe because there is no need to allocate page for every transmit. For RM decorations this is really important because I rather would have them fail as rarely as possible. If this would become a scalability issue then the granularity could be reconsidered. > > - tpm_buf_append(buf, (u8 *) &value2, 4); > > + tpm_buf_append(buf, (u8 *)&value2, 4); > > Please try and avoid this sort of churn in patches that change things.. It wasn't there on purpose. I do not know how these slipped. I can clean these up. > Jason /Jarkko
