Re: [RFC PATCH V5 3/5] PCI: Check platform specific ECAM quirks

[Tomasz Nowicki]

On 08.08.2016 17:34, Mark Salter wrote:
> On Mon, 2016-08-08 at 15:05 +0200, Tomasz Nowicki wrote:
> > Some platforms may not be fully compliant with generic set of PCI config
> > accessors. For these cases we implement the way to overwrite accessors
> > set. Algorithm traverses available quirk list (static array),
> > matches against <oem_id, oem_table_id, rev, domain, bus number range> and
> > returns pci_config_window structure with fancy PCI config ops.
> > oem_id, oem_table_id and rev come from MCFG table standard header.
> >
> > It is possible to define custom init call which is responsible for
> > setting up PCI configuration access accordingly to quirk requirements.
> > If custom init call is not defined, use standard pci_acpi_setup_ecam_mapping().
> >
> > pci_generic_ecam_ops will be used for platforms free from quirks.
> >
> > Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
> > Signed-off-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
> > Signed-off-by: Christopher Covington <cov@xxxxxxxxxxxxxx>
> > ---
> >  drivers/pci/host/Makefile      |  1 +
> >  drivers/pci/host/mcfg-quirks.c | 86 ++++++++++++++++++++++++++++++++++++++++++
> >  drivers/pci/host/mcfg-quirks.h | 20 ++++++++++
> >  include/linux/pci-acpi.h       |  2 +
> >  4 files changed, 109 insertions(+)
> >  create mode 100644 drivers/pci/host/mcfg-quirks.c
> >  create mode 100644 drivers/pci/host/mcfg-quirks.h
> >
> > diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
> > index 8843410..500cf78 100644
> > --- a/drivers/pci/host/Makefile
> > +++ b/drivers/pci/host/Makefile
> > @@ -31,3 +31,4 @@ obj-$(CONFIG_PCI_HOST_THUNDER_ECAM) += pci-thunder-ecam.o
> >  obj-$(CONFIG_PCI_HOST_THUNDER_PEM) += pci-thunder-pem.o
> >  obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
> >  obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
> > +obj-$(CONFIG_ACPI_MCFG) += mcfg-quirks.o
> > diff --git a/drivers/pci/host/mcfg-quirks.c b/drivers/pci/host/mcfg-quirks.c
> > new file mode 100644
> > index 0000000..aa9907b
> > --- /dev/null
> > +++ b/drivers/pci/host/mcfg-quirks.c
> > @@ -0,0 +1,86 @@
> > +/*
> > + * Copyright (C) 2016 Semihalf
> > + *	Author: Tomasz Nowicki <tn@xxxxxxxxxxxx>
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License, version 2, as
> > + * published by the Free Software Foundation (the "GPL").
> > + *
> > + * This program is distributed in the hope that it will be useful, but
> > + * WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > + * General Public License version 2 (GPLv2) for more details.
> > + *
> > + * You should have received a copy of the GNU General Public License
> > + * version 2 (GPLv2) along with this source code.
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/ioport.h>
> > +#include <linux/pci.h>
> > +#include <linux/pci-acpi.h>
> > +#include <linux/pci-ecam.h>
> > +
> > +#include "mcfg-quirks.h"
> > +
> > +struct pci_cfg_fixup {
> > +	char oem_id[ACPI_OEM_ID_SIZE + 1];
> > +	char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
> > +	u32 oem_revision;
> > +	struct resource domain_range;
> > +	struct resource bus_range;
> > +	struct pci_ops *ops;
> > +	struct pci_config_window *(*init)(struct acpi_pci_root *root,
> > +					  struct pci_ops *ops);
> > +};
> > +
> > +#define MCFG_DOM_RANGE(start, end)	DEFINE_RES_NAMED((start),	\
> > +						((end) - (start) + 1), NULL, 0)
> > +#define MCFG_DOM_ANY			MCFG_DOM_RANGE(0x0, 0xffff)
> > +#define MCFG_BUS_RANGE(start, end)	DEFINE_RES_NAMED((start),	\
> > +						((end) - (start) + 1),	\
> > +						NULL, IORESOURCE_BUS)
> > +#define MCFG_BUS_ANY			MCFG_BUS_RANGE(0x0, 0xff)
> > +
> > +static struct pci_cfg_fixup mcfg_quirks[] __initconst = {
>                                              ^^^^^^^^^^^^^^
>
> I get section warnings because pci_cfg_fixup_match() is not
> an init function.
>
> WARNING: vmlinux.o(.text+0x3f6c74): Section mismatch in reference from the function pci_mcfg_match_quirks() to the variable .init.rodata:$d
> The function pci_mcfg_match_quirks() references
> the variable __initconst $d.
> This is often because pci_mcfg_match_quirks lacks a __initconst
> annotation or the annotation of $d is wrong.

Thanks Mark. I will fix it.

Tomasz