| Message ID | 1465588519-11334-6-git-send-email-tn@semihalf.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Jun 10, 2016 at 09:55:13PM +0200, Tomasz Nowicki wrote: > According to PCI firmware specifications, on systems booting with ACPI, > PCI configuration for a host bridge must be set-up through the MCFG table > regions for non-hotpluggable bridges and _CBA method for hotpluggable ones. > > Current MCFG table handling code, as implemented for x86, cannot be > easily generalized owing to x86 specific quirks handling and related > code, which makes it hard to reuse on other architectures. > > In order to implement MCFG PCI configuration handling for new platforms > booting with ACPI (eg ARM64) this patch re-implements MCFG handling from > scratch in a streamlined fashion and provides (through a generic > interface available to all arches): > > - Simplified MCFG table parsing (executed through the pci_mmcfg_late_init() > hook as in current x86) > - MCFG regions look-up interface through domain:bus_start:bus_end tuple > > The new MCFG regions handling interface is added to generic ACPI code > so that existing architectures (eg x86) can be moved over to it and > architectures relying on MCFG for ACPI PCI config space can rely on it > without having to resort to arch specific implementations. > > Signed-off-by: Tomasz Nowicki <tn@semihalf.com> > Signed-off-by: Jayachandran C <jchandra@broadcom.com> > Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > --- > drivers/acpi/Kconfig | 3 ++ > drivers/acpi/Makefile | 1 + > drivers/acpi/pci_mcfg.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/pci-acpi.h | 2 ++ > include/linux/pci.h | 2 +- > 5 files changed, 99 insertions(+), 1 deletion(-) > create mode 100644 drivers/acpi/pci_mcfg.c > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > index b7e2e77..f98c328 100644 > --- a/drivers/acpi/Kconfig > +++ b/drivers/acpi/Kconfig > @@ -217,6 +217,9 @@ config ACPI_PROCESSOR_IDLE > bool > select CPU_IDLE > > +config ACPI_MCFG > + bool > + > config ACPI_CPPC_LIB > bool > depends on ACPI_PROCESSOR > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile > index 251ce85..632e81f 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_MCFG) += 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..d3c3e85 > --- /dev/null > +++ b/drivers/acpi/pci_mcfg.c > @@ -0,0 +1,92 @@ > +/* > + * Copyright (C) 2016 Broadcom > + * Author: Jayachandran C <jchandra@broadcom.com> > + * Copyright (C) 2016 Semihalf > + * Author: Tomasz Nowicki <tn@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. > + */ > + > +#define pr_fmt(fmt) "ACPI: " fmt > + > +#include <linux/kernel.h> > +#include <linux/pci.h> > +#include <linux/pci-acpi.h> > + > +/* Structure to hold entries from the MCFG table */ > +struct mcfg_entry { > + struct list_head list; > + phys_addr_t addr; > + u16 segment; > + u8 bus_start; > + u8 bus_end; > +}; > + > +/* List to save mcfg entries */ > +static LIST_HEAD(pci_mcfg_list); > + > +phys_addr_t pci_mcfg_lookup(u16 seg, struct resource *bus_res) > +{ > + struct mcfg_entry *e; > + > + /* > + * We expect exact match, unless MCFG entry end bus covers more than > + * specified by caller. > + */ > + list_for_each_entry(e, &pci_mcfg_list, list) { > + if (e->segment == seg && e->bus_start == bus_res->start && > + e->bus_end >= bus_res->end) > + return e->addr; I think this is more strict than necessary. Here's a common situation on x86: MCFG for domain 0000 [bus 00-ff] at [mem 0xe0000000-0xefffffff] ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-7f]) ACPI: PCI Root Bridge [PCI1] (domain 0000 [bus 80-ff]) We would fail on PCI1 because the start doesn't match. But what you have is fine for now, and we can loosen this up later if necessary. > + } > + > + return 0; > +} > + > +static __init int pci_mcfg_parse(struct acpi_table_header *header) > +{ > + struct acpi_table_mcfg *mcfg; > + struct acpi_mcfg_allocation *mptr; > + struct mcfg_entry *e, *arr; > + int i, n; > + > + if (header->length < sizeof(struct acpi_table_mcfg)) > + return -EINVAL; > + > + n = (header->length - sizeof(struct acpi_table_mcfg)) / > + sizeof(struct acpi_mcfg_allocation); > + mcfg = (struct acpi_table_mcfg *)header; > + mptr = (struct acpi_mcfg_allocation *) &mcfg[1]; > + > + arr = kcalloc(n, sizeof(*arr), GFP_KERNEL); > + if (!arr) > + return -ENOMEM; > + > + for (i = 0, e = arr; i < n; i++, mptr++, e++) { > + e->segment = mptr->pci_segment; > + e->addr = mptr->address; > + e->bus_start = mptr->start_bus_number; > + e->bus_end = mptr->end_bus_number; > + list_add(&e->list, &pci_mcfg_list); > + } > + > + pr_info("MCFG table detected, %d entries\n", n); > + return 0; > +} > + > +/* Interface called by ACPI - parse and save MCFG table */ > +void __init pci_mmcfg_late_init(void) > +{ > + int err = acpi_table_parse(ACPI_SIG_MCFG, pci_mcfg_parse); > + if (err) > + pr_err("Failed to parse MCFG (%d)\n", err); > +} > diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h > index 89ab057..7d63a66 100644 > --- a/include/linux/pci-acpi.h > +++ b/include/linux/pci-acpi.h > @@ -24,6 +24,8 @@ 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); > + > static inline acpi_handle acpi_find_root_bridge_handle(struct pci_dev *pdev) > { > struct pci_bus *pbus = pdev->bus; > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 12349de..ce03d65 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1723,7 +1723,7 @@ void pcibios_free_irq(struct pci_dev *dev); > extern struct dev_pm_ops pcibios_pm_ops; > #endif > > -#ifdef CONFIG_PCI_MMCONFIG > +#if defined(CONFIG_PCI_MMCONFIG) || defined(CONFIG_ACPI_MCFG) > void __init pci_mmcfg_early_init(void); > void __init pci_mmcfg_late_init(void); > #else > -- > 1.9.1 >
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index b7e2e77..f98c328 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -217,6 +217,9 @@ config ACPI_PROCESSOR_IDLE bool select CPU_IDLE +config ACPI_MCFG + bool + config ACPI_CPPC_LIB bool depends on ACPI_PROCESSOR diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 251ce85..632e81f 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_MCFG) += 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..d3c3e85 --- /dev/null +++ b/drivers/acpi/pci_mcfg.c @@ -0,0 +1,92 @@ +/* + * Copyright (C) 2016 Broadcom + * Author: Jayachandran C <jchandra@broadcom.com> + * Copyright (C) 2016 Semihalf + * Author: Tomasz Nowicki <tn@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. + */ + +#define pr_fmt(fmt) "ACPI: " fmt + +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/pci-acpi.h> + +/* Structure to hold entries from the MCFG table */ +struct mcfg_entry { + struct list_head list; + phys_addr_t addr; + u16 segment; + u8 bus_start; + u8 bus_end; +}; + +/* List to save mcfg entries */ +static LIST_HEAD(pci_mcfg_list); + +phys_addr_t pci_mcfg_lookup(u16 seg, struct resource *bus_res) +{ + struct mcfg_entry *e; + + /* + * We expect exact match, unless MCFG entry end bus covers more than + * specified by caller. + */ + list_for_each_entry(e, &pci_mcfg_list, list) { + if (e->segment == seg && e->bus_start == bus_res->start && + e->bus_end >= bus_res->end) + return e->addr; + } + + return 0; +} + +static __init int pci_mcfg_parse(struct acpi_table_header *header) +{ + struct acpi_table_mcfg *mcfg; + struct acpi_mcfg_allocation *mptr; + struct mcfg_entry *e, *arr; + int i, n; + + if (header->length < sizeof(struct acpi_table_mcfg)) + return -EINVAL; + + n = (header->length - sizeof(struct acpi_table_mcfg)) / + sizeof(struct acpi_mcfg_allocation); + mcfg = (struct acpi_table_mcfg *)header; + mptr = (struct acpi_mcfg_allocation *) &mcfg[1]; + + arr = kcalloc(n, sizeof(*arr), GFP_KERNEL); + if (!arr) + return -ENOMEM; + + for (i = 0, e = arr; i < n; i++, mptr++, e++) { + e->segment = mptr->pci_segment; + e->addr = mptr->address; + e->bus_start = mptr->start_bus_number; + e->bus_end = mptr->end_bus_number; + list_add(&e->list, &pci_mcfg_list); + } + + pr_info("MCFG table detected, %d entries\n", n); + return 0; +} + +/* Interface called by ACPI - parse and save MCFG table */ +void __init pci_mmcfg_late_init(void) +{ + int err = acpi_table_parse(ACPI_SIG_MCFG, pci_mcfg_parse); + if (err) + pr_err("Failed to parse MCFG (%d)\n", err); +} diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h index 89ab057..7d63a66 100644 --- a/include/linux/pci-acpi.h +++ b/include/linux/pci-acpi.h @@ -24,6 +24,8 @@ 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); + static inline acpi_handle acpi_find_root_bridge_handle(struct pci_dev *pdev) { struct pci_bus *pbus = pdev->bus; diff --git a/include/linux/pci.h b/include/linux/pci.h index 12349de..ce03d65 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1723,7 +1723,7 @@ void pcibios_free_irq(struct pci_dev *dev); extern struct dev_pm_ops pcibios_pm_ops; #endif -#ifdef CONFIG_PCI_MMCONFIG +#if defined(CONFIG_PCI_MMCONFIG) || defined(CONFIG_ACPI_MCFG) void __init pci_mmcfg_early_init(void); void __init pci_mmcfg_late_init(void); #else