Re: [PATCH v13 3/5] s390/pci: Improve FMB memory management

[Niklas Schnelle <schnelle@linux.ibm.com>]

On Wed, 2026-11-11 at 11:27 -0500, Omar Elghoul wrote:
> Refactor the FMB memory management code to use kzalloc() instead of a
> dedicated kmem_cache. kzalloc() already guarantees adequate alignment
> for power-of-two sizes, rendering the kmem_cache approach unnecessary.
> This simplifies both the initialization and cleanup procedures.
> 
> Allocate the FMB once upon first enable and keep it for the lifetime of
> the zdev instead of freeing it on every disable. Defer freeing the
> buffer until device teardown in zpci_release_device(). Add the field
> fmb_enabled to struct zpci_dev as the new FMB liveness bool, since a
> non-null FMB pointer no longer implies FMB enablement in firmware.
> 
> Signed-off-by: Omar Elghoul <oelghoul@linux.ibm.com>
> ---
>  arch/s390/include/asm/pci.h |  1 +
>  arch/s390/pci/pci.c         | 61 +++++++++++++++++++++----------------
>  arch/s390/pci/pci_debug.c   |  2 +-
>  3 files changed, 37 insertions(+), 27 deletions(-)

And this one too looks good now. In the beginning I had really guessed
that this would have been a series with few hurdles but the devil
really is in the detail. Thanks for the great work.

Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>

Thanks,
Niklas