Message-ID: <bc6b967e461c066bb248437597195c0fd737e6e3.camel@linux.ibm.com>
Subject: Re: [PATCH 12/32] s390/pci: get SHM information from list pci
From:   Niklas Schnelle <schnelle@linux.ibm.com>
To:     Christian Borntraeger <borntraeger@linux.ibm.com>,
        Matthew Rosato <mjrosato@linux.ibm.com>,
        linux-s390@vger.kernel.org
Cc:     alex.williamson@redhat.com, cohuck@redhat.com,
        farman@linux.ibm.com, pmorel@linux.ibm.com, hca@linux.ibm.com,
        gor@linux.ibm.com, gerald.schaefer@linux.ibm.com,
        agordeev@linux.ibm.com, frankja@linux.ibm.com, david@redhat.com,
        imbrenda@linux.ibm.com, vneethv@linux.ibm.com,
        oberpar@linux.ibm.com, freude@linux.ibm.com, thuth@redhat.com,
        pasic@linux.ibm.com, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Date:   Fri, 10 Dec 2021 09:45:56 +0100
In-Reply-To: <cabce091-531a-de77-5b90-9ee1f1482da7@linux.ibm.com>
References: <20211207205743.150299-1-mjrosato@linux.ibm.com>
         <20211207205743.150299-13-mjrosato@linux.ibm.com>
         <cabce091-531a-de77-5b90-9ee1f1482da7@linux.ibm.com>
Content-Type: text/plain; charset="UTF-8"
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Thu, 2021-12-09 at 16:47 +0100, Christian Borntraeger wrote:
> Am 07.12.21 um 21:57 schrieb Matthew Rosato:
> > KVM will need information on the special handle mask used to indicate
> > emulated devices.  In order to obtain this, a new type of list pci call
> > must be made to gather the information.  Remove the unused data pointer
> > from clp_list_pci and __clp_add and instead optionally pass a pointer to
> > a model-dependent-data field.  Additionally, allow for clp_list_pci calls
> > that don't specify a callback - in this case, just do the first pass of
> > list pci and exit.
> > 
> > Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
> > ---
> >   arch/s390/include/asm/pci.h     |  6 ++++++
> >   arch/s390/include/asm/pci_clp.h |  2 +-
> >   arch/s390/pci/pci.c             | 19 +++++++++++++++++++
> >   arch/s390/pci/pci_clp.c         | 16 ++++++++++------
> >   4 files changed, 36 insertions(+), 7 deletions(-)
> > 
---8<---
> >   
> > +int zpci_get_mdd(u32 *mdd)
> > +{
> > +	struct clp_req_rsp_list_pci *rrb;
> > +	int rc;
> > +
> > +	if (!mdd)
> > +		return -EINVAL;
> > +
> > +	rrb = clp_alloc_block(GFP_KERNEL);
> > +	if (!rrb)
> > +		return -ENOMEM;
> > +
> > +	rc = clp_list_pci(rrb, mdd, NULL);
> > +
> > +	clp_free_block(rrb);
> > +	return rc;
> > +}
> > +EXPORT_SYMBOL_GPL(zpci_get_mdd);
> 
> Maybe move this into pci_clp.c to avoid the export of clp_alloc_block and void clp_free_block?
> Niklas?

That was actually my idea. I'm thinking of moving clp_get_state(),
clp_scan_pci_devices(), ans clp_refresh_fh() to pci.c too because I
feel these deal with higher level concerns than the rest of pci_clp.c.

I have no strong opinion though and might be thinking ahead to much
here. With the change discussed in the other mail of not modifying
clp_list_pci() maybe it would be better to keep it here and thus this
patch more focused and minimal and then possibly move it with the other
similar functions.