Re: [PATCH v9 10/15] ACPI: platform-msi: retrieve dev id from IORT

[Hanjun Guo]

On 03/29/2017 08:38 PM, Lorenzo Pieralisi wrote:
> On Wed, Mar 29, 2017 at 07:52:48PM +0800, Hanjun Guo wrote:
> > Hi Lorenzo,
> >
> > On 03/29/2017 06:14 PM, Lorenzo Pieralisi wrote:
> > > Hi Hanjun, Marc,
> > >
> > > On Tue, Mar 07, 2017 at 08:40:05PM +0800, Hanjun Guo wrote:
> > > > From: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> > > >
> > > > For devices connecting to ITS, the devices need to identify themself
> > > > through a dev id; this dev id is represented in the IORT table in named
> > > > component node [1] for platform devices, so this patch adds code that
> > > > scans the IORT table to retrieve the devices' dev id.
> > > >
> > > > Leveraging the iort_node_map_platform_id() IORT API, add a new function
> > > > call, iort_pmsi_get_dev_id() and use it in its_pmsi_prepare() to allow
> > > > retrieving dev id in ACPI platforms.
> > > >
> > > > [1]: https://static.docs.arm.com/den0049/b/DEN0049B_IO_Remapping_Table.pdf
> > > >
> > > > Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> > > > [lorenzo.pieralisi@xxxxxxx: rewrote commit log]
> > > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> > > > Tested-by: Ming Lei <ming.lei@xxxxxxxxxxxxx>
> > > > Tested-by: Wei Xu <xuwei5@xxxxxxxxxxxxx>
> > > > Tested-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
> > > > Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
> > > > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> > > > Cc: Tomasz Nowicki <tn@xxxxxxxxxxxx>
> > > > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > > > ---
> > > >   drivers/acpi/arm64/iort.c                     | 24 ++++++++++++++++++++++++
> > > >   drivers/irqchip/irq-gic-v3-its-platform-msi.c |  3 ++-
> > > >   include/linux/acpi_iort.h                     |  5 +++++
> > > >   3 files changed, 31 insertions(+), 1 deletion(-)
> > >
> > > To simplify merging ACPI/IRQCHIP changes via different trees it
> > > would be good to split this patch; I am not sure what's the best
> > > way of handling it though given that we would end up in a merge
> > > ordering dependency anyway (ie we can create an empty stub
> > > for iort_pmsi_get_dev_id() but that would create a dependency
> > > between ARM64 and irqchip trees anyway).
> >
> > The first 12 patches for ACPI platform MSI and later 3 patches
> > for mbigen have no "physical" dependency, which means they can
> > be merged and compiled independently, they only have functional
> > dependency only.
> >
> > We already had SAS, XGE, USB and even UART drivers depend on
> > the mbigen ACPI support, so I don't think the dependency of ACPI
> > platform MSI and mbigen patches cares much if those two parts are
> > merged in one merge window, even they are merged independently via
> > different tree.
> >
> > > Please let me know what's your preferred way of handling this.
> >
> > So in my opinion, they can be merged independently via ARM64 and
> > irqchip tree with no ordering dependency, is it OK?
>
> I am speaking about merging MBIgen AND ITS patches via IRQCHIP and
> ACPI/IORT for ARM64, that's why I replied to this patch. I do not
> think that's feasible to split patches in two separate branches
> without having a dependency between them.
>
> Sure, the last three patches can go via IRQCHIP but that was not
> my question :)

Sorry, I misunderstood that :(

Since it's not feasible to split patches, the best way I got is that
we get Marc's ack then merge it.

Marc, Lorenzo, is this OK?

Thanks
Hanjun