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 <t...@semihalf.com>
> Signed-off-by: Dongdong Liu <liudongdo...@huawei.com>
> Signed-off-by: Christopher Covington <c...@codeaurora.org>
> ---
> 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 <t...@semihalf.com>
> + *
> + * 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.
> +/* { OEM_ID, OEM_TABLE_ID, REV, DOMAIN, BUS_RANGE, pci_ops, init_hook }, */
> +};
> +
> +static bool pci_mcfg_fixup_match(struct pci_cfg_fixup *f,
> + struct acpi_table_header *mcfg_header)
> +{
> + return (!memcmp(f->oem_id, mcfg_header->oem_id, ACPI_OEM_ID_SIZE) &&
> + !memcmp(f->oem_table_id, mcfg_header->oem_table_id,
> + ACPI_OEM_TABLE_ID_SIZE) &&
> + f->oem_revision == mcfg_header->oem_revision);
> +}
> +
> +struct pci_config_window *pci_mcfg_match_quirks(struct acpi_pci_root *root)
> +{
> + struct resource dom_res = MCFG_DOM_RANGE(root->segment, root->segment);
> + struct resource *bus_res = &root->secondary;
> + struct pci_cfg_fixup *f = mcfg_quirks;
> + struct acpi_table_header *mcfg_header;
> + acpi_status status;
> + int i;
> +
> + status = acpi_get_table(ACPI_SIG_MCFG, 0, &mcfg_header);
> + if (ACPI_FAILURE(status))
> + return NULL;
> +
> + /*
> + * First match against PCI topology <domain:bus> then use OEM ID, OEM
> + * table ID, and OEM revision from MCFG table standard header.
> + */
> + for (i = 0; i < ARRAY_SIZE(mcfg_quirks); i++, f++) {
> + if (resource_contains(&f->domain_range, &dom_res) &&
> + resource_contains(&f->bus_range, bus_res) &&
> + pci_mcfg_fixup_match(f, mcfg_header)) {
> + dev_info(&root->device->dev, "Applying PCI MCFG quirks
> for %s %s rev: %d\n",
> + f->oem_id, f->oem_table_id, f->oem_revision);
> + return f->init ? f->init(root, f->ops) :
> + pci_acpi_setup_ecam_mapping(root, f->ops);
> + }
> + }
> + return pci_acpi_setup_ecam_mapping(root, &pci_generic_ecam_ops.pci_ops);
> +}
> diff --git a/drivers/pci/host/mcfg-quirks.h b/drivers/pci/host/mcfg-quirks.h
> new file mode 100644
> index 0000000..45cbd16
> --- /dev/null
> +++ b/drivers/pci/host/mcfg-quirks.h
> @@ -0,0 +1,20 @@
> +/*
> + * 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.
> + */
> +
> +#ifndef __MCFG_QUIRKS_H__
> +#define __MCFG_QUIRKS_H__
> +
> +/* MCFG quirks initialize call list */
> +
> +#endif /* __MCFG_QUIRKS_H__ */
> diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
> index e9bfe00..28cdce4 100644
> --- a/include/linux/pci-acpi.h
> +++ b/include/linux/pci-acpi.h
> @@ -25,6 +25,8 @@ static inline acpi_status
> pci_acpi_remove_pm_notifier(struct acpi_device *dev)
> extern phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle);
>
> extern phys_addr_t pci_mcfg_lookup(u16 domain, struct resource *bus_res);
> +extern struct pci_config_window *
> +pci_mcfg_match_quirks(struct acpi_pci_root *root);
>
> extern struct pci_config_window *
> pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root, struct pci_ops *ops);
