From mboxrd@z Thu Jan 1 00:00:00 1970 From: helgaas@kernel.org (Bjorn Helgaas) Date: Sun, 4 Sep 2016 21:59:08 -0500 Subject: [RFC PATCH V5 3/5] PCI: Check platform specific ECAM quirks In-Reply-To: <1470661541-26270-4-git-send-email-tn@semihalf.com> References: <1470661541-26270-1-git-send-email-tn@semihalf.com> <1470661541-26270-4-git-send-email-tn@semihalf.com> Message-ID: <20160905025908.GG30488@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Aug 08, 2016 at 03:05:39PM +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 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 > Signed-off-by: Dongdong Liu > Signed-off-by: Christopher Covington > --- > 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 > + * > + * 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 > +#include > +#include > +#include > +#include > + > +#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 = { > +/* { 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; I remember working out why pci_mcfg_parse() has to cache the data from MCFG, but I don't remember the actual reason... a comment there would have been helpful. Anyway, now I wonder why it's OK to call acpi_get_table(ACPI_SIG_MCFG) again here. I guess I'd be inclined to just cache the OEM info along with the rest of the data so you don't have to get the table again here. > + /* > + * First match against PCI topology 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); I think the scope of these MCFG quirks is to: 1) Override (or even fabricate) a MEM resource to be used as ECAM space, and 2) Supply a pci_ecam_ops structure if we need something other than pci_generic_ecam_ops Today, pci_mcfg_lookup() merely returns a physical address. I didn't chase down where (or whether) that is turned into a struct resource that we put in the iomem tree. I wonder if pci_mcfg_lookup() could be extended to return a resource and a pci_ecam_ops pointer, and handle the quirk application internally, e.g., int pci_mcfg_lookup(u16 seg, struct resource *bus_res, struct resource *cfgres, struct pci_ecam_ops **ecam_ops) { struct resource res; struct pci_ecam_ops *ops; struct mcfg_entry *e; memset(&res, 0, sizeof(res)); res.flags = IORESOURCE_MEM; e = pci_mcfg_list_search(seg, bus_res); if (e) { res.start = e->addr; res.end = res.start + ...; } ops = &pci_generic_ecam_ops; ret = pci_mcfg_match_quirks(seg, bus_res, &res, &ops); if (ret) return ret; *cfgres = res; *ecam_ops = ops; return 0; } Then the quirks would see any mem resource we discovered via MCFG, and they would see the default pci_ecam_ops, and they could override whatever they needed to. That would make pci_acpi_setup_ecam_mapping() look something like this: pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root) { struct resource cfgres; struct pci_ecam_ops *ecam_ops; ret = pci_mcfg_lookup(root->segment, &root->secondary, &cfgres, &ecam_ops); if (ret) { dev_err(..., "ECAM region not found\n"); return ret; } cfg = pci_ecam_create(&root->device->dev, &cfgres, bus_res, ecam_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); > -- > 1.9.1 >