Re: [PATCH V6 2/2] PCI/ACPI: hisi: Add ACPI support for HiSilicon SoCs Host Controllers

[Graeme Gregory <gg@slimlogic.co.uk>]

On Tue, Nov 22, 2016 at 03:05:29PM +0000, Gabriele Paoloni wrote:
> Hi Tomasz
> 
> > -----Original Message-----
> > From: Tomasz Nowicki [mailto:tn@semihalf.com]
> > Sent: 22 November 2016 13:58
> > To: liudongdong (C); helgaas@kernel.org; arnd@arndb.de;
> > rafael@kernel.org; Lorenzo.Pieralisi@arm.com; Wangzhou (B);
> > pratyush.anand@gmail.com
> > Cc: linux-pci@vger.kernel.org; linux-acpi@vger.kernel.org; linux-
> > kernel@vger.kernel.org; jcm@redhat.com; Gabriele Paoloni; Chenxin
> > (Charles); hanjun.guo@linaro.org; Linuxarm
> > Subject: Re: [PATCH V6 2/2] PCI/ACPI: hisi: Add ACPI support for
> > HiSilicon SoCs Host Controllers
> > 
> > On 22.11.2016 13:08, Dongdong Liu wrote:
> > > PCIe controller in Hip05/HIP06/HIP07 SoCs is not ECAM compliant.
> > > It is non ECAM only for the RC bus config space;for any other bus
> > > underneath the root bus we support ECAM access.
> > > Add specific quirks for PCI config space accessors.This involves:
> > > 1. New initialization call hisi_pcie_init() to obtain rc base
> > > addresses from PNP0C02 at the root of the ACPI namespace (under
> > \_SB).
> > > 2. New entry in common quirk array.
> > >
> > > Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>
> > > Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.com>
> > > ---
> > >  MAINTAINERS                       |   1 +
> > >  drivers/acpi/pci_mcfg.c           |  13 +++++
> > >  drivers/pci/host/Kconfig          |   7 +++
> > >  drivers/pci/host/Makefile         |   1 +
> > >  drivers/pci/host/pcie-hisi-acpi.c | 119
> > ++++++++++++++++++++++++++++++++++++++
> > >  include/linux/pci-ecam.h          |   5 ++
> > >  6 files changed, 146 insertions(+)
> > >  create mode 100644 drivers/pci/host/pcie-hisi-acpi.c
> > >
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > index 1cd38a7..b224caa 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -9358,6 +9358,7 @@ L:	linux-pci@vger.kernel.org
> > >  S:	Maintained
> > >  F:	Documentation/devicetree/bindings/pci/hisilicon-pcie.txt
> > >  F:	drivers/pci/host/pcie-hisi.c
> > > +F:	drivers/pci/host/pcie-hisi-acpi.c
> > >
> > >  PCIE DRIVER FOR ROCKCHIP
> > >  M:	Shawn Lin <shawn.lin@rock-chips.com>
> > > diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
> > > index ac21db3..3297c5a 100644
> > > --- a/drivers/acpi/pci_mcfg.c
> > > +++ b/drivers/acpi/pci_mcfg.c
> > > @@ -57,6 +57,19 @@ struct mcfg_fixup {
> > >  	{ "QCOM  ", "QDF2432 ", 1, 5, MCFG_BUS_ANY, &pci_32b_ops },
> > >  	{ "QCOM  ", "QDF2432 ", 1, 6, MCFG_BUS_ANY, &pci_32b_ops },
> > >  	{ "QCOM  ", "QDF2432 ", 1, 7, MCFG_BUS_ANY, &pci_32b_ops },
> > > +#ifdef CONFIG_PCI_ECAM_QUIRKS
> > > +	#define PCI_ACPI_QUIRK_QUAD_DOM(table_id, seg, ops) \
> > > +	{ "HISI  ", table_id, 0, seg + 0, MCFG_BUS_ANY, ops }, \
> > > +	{ "HISI  ", table_id, 0, seg + 1, MCFG_BUS_ANY, ops }, \
> > > +	{ "HISI  ", table_id, 0, seg + 2, MCFG_BUS_ANY, ops }, \
> > > +	{ "HISI  ", table_id, 0, seg + 3, MCFG_BUS_ANY, ops }
> > > +	PCI_ACPI_QUIRK_QUAD_DOM("HIP05   ", 0, &hisi_pcie_ops),
> > > +	PCI_ACPI_QUIRK_QUAD_DOM("HIP06   ", 0, &hisi_pcie_ops),
> > > +	PCI_ACPI_QUIRK_QUAD_DOM("HIP07   ", 0, &hisi_pcie_ops),
> > > +	PCI_ACPI_QUIRK_QUAD_DOM("HIP07   ", 4, &hisi_pcie_ops),
> > > +	PCI_ACPI_QUIRK_QUAD_DOM("HIP07   ", 8, &hisi_pcie_ops),
> > > +	PCI_ACPI_QUIRK_QUAD_DOM("HIP07   ", 12, &hisi_pcie_ops),
> > > +#endif
> > >  };
> > >
> > >  static char mcfg_oem_id[ACPI_OEM_ID_SIZE];
> > > diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> > > index ae98644..1fbade5 100644
> > > --- a/drivers/pci/host/Kconfig
> > > +++ b/drivers/pci/host/Kconfig
> > > @@ -301,4 +301,11 @@ config VMD
> > >  	  To compile this driver as a module, choose M here: the
> > >  	  module will be called vmd.
> > >
> > > +config PCI_ECAM_QUIRKS
> > > +	bool "PCI ECAM quirks for ARM64 platform"
> > > +	depends on PCI_ECAM && ARM64 && ACPI
> > > +	help
> > > +	  Say y here to enable your platform-specific config access that
> > > +	  is not ECAM compliant.
> > > +
> > 
> > ARM64 selects PCI_ECAM for ACPI anyway so we can skip it here.
> 
> Yes sure
> 
> > 
> > How about selecting PCI_ECAM_QUIRKS from ARM64 Kconfig:
> 
> I don't think we should assume that ARM64 platforms should
> support quirks by default...
> i.e. from my perspective the quirk module should go in only
> if strictly required by the platform you're working on.
> 
> Thoughts?
> 
> Thanks
> 
No, same kernel multiple machines is the model, code should go in
unconditional.

Graeme