On Tue, Jun 25, 2019 at 10:27 PM Vaibhav Jain [off-list ref] wrote:

The new hcall named H_SCM_UNBIND_ALL has been introduce that can
unbind all the memory drc memory-blocks assigned to an lpar.

This is a little muddy. For normal memory each block has a DRC so you
can add/remove individual blocks by configuring or deconfiguring the
DRC for that block. For storage class memory the DRC refers to the SCM
volume as a whole rather than an individual block so a "memory DRC"
isn't really what you're taking about here.

This is probably being a little pedantic, but I find the whole DRC
system confusing enough as-is so it's good to be clear about these
things.

more efficient than using H_SCM_UNBIND_MEM as currently we don't
support partial unbind of drc memory-blocks.

Hence this patch proposes following changes to drc_pmem_unbind():

    * Update drc_pmem_unbind() to replace hcall H_SCM_UNBIND_MEM to
      H_SCM_UNBIND_ALL.

    * Update drc_pmem_unbind() to handles cases when PHYP asks the guest
      kernel to wait for specific amount of time before retrying the
      hcall via the 'LONG_BUSY' return value.

* Ensure appropriate error code is returned back from the function
      in case of an error.

Signed-off-by: Vaibhav Jain <redacted>
---
Change-log:

v2:
* Added a dev_dbg when unbind operation succeeds [Oliver]
* Changed type of variable 'rc' to int64_t [Oliver]
* Removed the code that was logging a warning in case bind operation
  takes >1-seconds [Oliver]
* Spinned off changes to hvcall.h as a separate patch. [Oliver]

Looks good otherwise, when you respin feel free to add:

Reviewed-by: Oliver O'Halloran <oohall@gmail.com>