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

[Gabriele Paoloni <gabriele.paoloni@huawei.com>]

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

Gab

> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 30398db..9743186 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -105,6 +105,7 @@ config ARM64
>          select OF_EARLY_FLATTREE
>          select OF_RESERVED_MEM
>          select PCI_ECAM if ACPI
> +       select PCI_ECAM_QUIRKS if ACPI
>          select POWER_RESET
>          select POWER_SUPPLY
>          select SPARSE_IRQ
> 
> I agree with Bjorn, we should not have to turn on platform-specific
> config options for ARM64 & ACPI.
> 
> Thanks,
> Tomasz