From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755275AbcESQ4p (ORCPT ); Thu, 19 May 2016 12:56:45 -0400 Received: from smtp.nue.novell.com ([195.135.221.5]:41243 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754484AbcESQ4n (ORCPT ); Thu, 19 May 2016 12:56:43 -0400 Subject: Re: [PATCH V7 08/11] pci, acpi: Support for ACPI based generic PCI host controller To: Tomasz Nowicki , helgaas@kernel.org, arnd@arndb.de, will.deacon@arm.com, catalin.marinas@arm.com, rafael@kernel.org, hanjun.guo@linaro.org, Lorenzo.Pieralisi@arm.com, okaya@codeaurora.org, jchandra@broadcom.com References: <1462893601-8937-1-git-send-email-tn@semihalf.com> <1462893601-8937-9-git-send-email-tn@semihalf.com> Cc: jcm@redhat.com, linaro-acpi@lists.linaro.org, linux-pci@vger.kernel.org, dhdang@apm.com, Liviu.Dudau@arm.com, ddaney@caviumnetworks.com, jeremy.linton@arm.com, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, robert.richter@caviumnetworks.com, cov@codeaurora.org, Suravee.Suthikulpanit@amd.com, msalter@redhat.com, wangyijing@huawei.com, mw@semihalf.com, andrea.gallo@linaro.org, linux-arm-kernel@lists.infradead.org, liudongdong3@huawei.com From: Matthias Brugger Message-ID: <573DF039.5040405@suse.com> Date: Thu, 19 May 2016 18:56:25 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.0 MIME-Version: 1.0 In-Reply-To: <1462893601-8937-9-git-send-email-tn@semihalf.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/05/16 17:19, Tomasz Nowicki wrote: > This patch is going to implement generic PCI host controller for > ACPI world, similar to what pci-host-generic.c driver does for DT world. > > All such drivers, which we have seen so far, were implemented within > arch/ directory since they had some arch assumptions (x86 and ia64). > However, they all are doing similar thing, so it makes sense to find > some common code and abstract it into the generic driver. > > In order to handle PCI config space regions properly, we define new > MCFG interface which does sanity checks on MCFG table and keeps its > root pointer. User is able to lookup MCFG regions based on that root > pointer and specified domain:bus_start:bus_end touple. We are using > pci_mmcfg_late_init old prototype to avoid another function name. > > The implementation of pci_acpi_scan_root() looks up the MCFG entries > and sets up a new mapping (regions are not mapped until host controller ask > for it). Generic PCI functions are used for accessing config space. > Driver selects PCI_ECAM and uses functions from drivers/pci/ecam.h > to create and access ECAM mappings. > > As mentioned in Kconfig help section, ACPI_PCI_HOST_GENERIC choice > should be made on a per-architecture basis. > > Signed-off-by: Tomasz Nowicki > Signed-off-by: Jayachandran C > --- > drivers/acpi/Kconfig | 8 +++ > drivers/acpi/Makefile | 1 + > drivers/acpi/pci_mcfg.c | 97 ++++++++++++++++++++++++++ > drivers/acpi/pci_root_generic.c | 149 ++++++++++++++++++++++++++++++++++++++++ > drivers/pci/ecam.h | 5 ++ > include/linux/pci-acpi.h | 5 ++ > include/linux/pci.h | 5 +- > 7 files changed, 269 insertions(+), 1 deletion(-) > create mode 100644 drivers/acpi/pci_mcfg.c > create mode 100644 drivers/acpi/pci_root_generic.c > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > index 183ffa3..44afc76 100644 > --- a/drivers/acpi/Kconfig > +++ b/drivers/acpi/Kconfig > @@ -346,6 +346,14 @@ config ACPI_PCI_SLOT > i.e., segment/bus/device/function tuples, with physical slots in > the system. If you are unsure, say N. > > +config ACPI_PCI_HOST_GENERIC > + bool > + select PCI_ECAM > + help > + Select this config option from the architecture Kconfig, > + if it is preferred to enable ACPI PCI host controller driver which > + has no arch-specific assumptions. > + > config X86_PM_TIMER > bool "Power Management Timer Support" if EXPERT > depends on X86 > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile > index 81e5cbc..627a2b7 100644 > --- a/drivers/acpi/Makefile > +++ b/drivers/acpi/Makefile > @@ -40,6 +40,7 @@ acpi-$(CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC) += processor_pdc.o > acpi-y += ec.o > acpi-$(CONFIG_ACPI_DOCK) += dock.o > acpi-y += pci_root.o pci_link.o pci_irq.o > +obj-$(CONFIG_ACPI_PCI_HOST_GENERIC) += pci_root_generic.o pci_mcfg.o > acpi-y += acpi_lpss.o acpi_apd.o > acpi-y += acpi_platform.o > acpi-y += acpi_pnp.o > diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c > new file mode 100644 > index 0000000..373d079 > --- /dev/null > +++ b/drivers/acpi/pci_mcfg.c > @@ -0,0 +1,97 @@ > +/* > + * Copyright (C) 2016 Broadcom > + * Author: Jayachandran C > + * 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 > + > +#define PREFIX "ACPI: " > + > +/* Root pointer to the mapped MCFG table */ > +static struct acpi_table_mcfg *mcfg_table; > + > +#define MCFG_ENTRIES(mcfg_ptr) (((mcfg_ptr)->header.length - \ > + sizeof(struct acpi_table_mcfg)) / \ > + sizeof(struct acpi_mcfg_allocation)) > + > +static phys_addr_t pci_mcfg_lookup_static(u16 seg, u8 bus_start, u8 bus_end) > +{ > + struct acpi_mcfg_allocation *mptr; > + int i; > + > + if (!mcfg_table) { > + pr_err(PREFIX "MCFG table not available, lookup failed\n"); > + return -ENXIO; > + } > + > + mptr = (struct acpi_mcfg_allocation *) &mcfg_table[1]; > + > + /* > + * We expect exact match, unless MCFG entry end bus covers more than > + * specified by caller. > + */ > + for (i = 0; i < MCFG_ENTRIES(mcfg_table); i++, mptr++) { > + if (mptr->pci_segment == seg && > + mptr->start_bus_number == bus_start && > + mptr->end_bus_number >= bus_end) { > + return mptr->address; > + } > + } > + > + return -ENXIO; > +} > + > +phys_addr_t pci_mcfg_lookup(struct acpi_device *device, u16 seg, > + struct resource *bus_res) > +{ > + phys_addr_t addr; > + > + addr = acpi_pci_root_get_mcfg_addr(device->handle); > + if (addr) > + return addr; > + > + return pci_mcfg_lookup_static(seg, bus_res->start, bus_res->end); > +} > + > +static __init int pci_mcfg_parse(struct acpi_table_header *header) > +{ > + struct acpi_table_mcfg *mcfg; > + int n; > + > + if (!header) > + return -EINVAL; Maybe that's bike shedding, but acpi_table_parse already checks that the table passed to the handler exists, so this is redundant. Regards, Matthias