From: Jayachandran C jchandra@broadcom.com

This header will be used from arch/arm64 for ACPI PCI implementation so it needs to be moved out of drivers/pci.

Update users of the header file to use the new name. No functional changes.

Signed-off-by: Jayachandran C jchandra@broadcom.com Acked-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com --- drivers/pci/ecam.c | 3 +- drivers/pci/ecam.h | 67 ------------------------------------- drivers/pci/host/pci-host-common.c | 3 +- drivers/pci/host/pci-host-generic.c | 3 +- drivers/pci/host/pci-thunder-ecam.c | 3 +- drivers/pci/host/pci-thunder-pem.c | 3 +- include/linux/pci-ecam.h | 67 +++++++++++++++++++++++++++++++++++++ 7 files changed, 72 insertions(+), 77 deletions(-) delete mode 100644 drivers/pci/ecam.h create mode 100644 include/linux/pci-ecam.h

diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c index f9832ad..820e26b 100644 --- a/drivers/pci/ecam.c +++ b/drivers/pci/ecam.c @@ -19,10 +19,9 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/pci.h> +#include <linux/pci-ecam.h> #include <linux/slab.h>

-#include "ecam.h" - /* * On 64-bit systems, we do a single ioremap for the whole config space * since we have enough virtual address range available. On 32-bit, we diff --git a/drivers/pci/ecam.h b/drivers/pci/ecam.h deleted file mode 100644 index 9878beb..0000000 --- a/drivers/pci/ecam.h +++ /dev/null @@ -1,67 +0,0 @@ -/* - * Copyright 2016 Broadcom - * - * 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 DRIVERS_PCI_ECAM_H -#define DRIVERS_PCI_ECAM_H - -#include <linux/kernel.h> -#include <linux/platform_device.h> - -/* - * struct to hold pci ops and bus shift of the config window - * for a PCI controller. - */ -struct pci_config_window; -struct pci_ecam_ops { - unsigned int bus_shift; - struct pci_ops pci_ops; - int (*init)(struct device *, - struct pci_config_window *); -}; - -/* - * struct to hold the mappings of a config space window. This - * is expected to be used as sysdata for PCI controllers that - * use ECAM. - */ -struct pci_config_window { - struct resource res; - struct resource busr; - void *priv; - struct pci_ecam_ops *ops; - union { - void __iomem *win; /* 64-bit single mapping */ - void __iomem **winp; /* 32-bit per-bus mapping */ - }; -}; - -/* create and free pci_config_window */ -struct pci_config_window *pci_ecam_create(struct device *dev, - struct resource *cfgres, struct resource *busr, - struct pci_ecam_ops *ops); -void pci_ecam_free(struct pci_config_window *cfg); - -/* map_bus when ->sysdata is an instance of pci_config_window */ -void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn, - int where); -/* default ECAM ops */ -extern struct pci_ecam_ops pci_generic_ecam_ops; - -#ifdef CONFIG_PCI_HOST_GENERIC -/* for DT-based PCI controllers that support ECAM */ -int pci_host_common_probe(struct platform_device *pdev, - struct pci_ecam_ops *ops); -#endif -#endif diff --git a/drivers/pci/host/pci-host-common.c b/drivers/pci/host/pci-host-common.c index 8cba7ab..c18b9e3 100644 --- a/drivers/pci/host/pci-host-common.c +++ b/drivers/pci/host/pci-host-common.c @@ -20,10 +20,9 @@ #include <linux/module.h> #include <linux/of_address.h> #include <linux/of_pci.h> +#include <linux/pci-ecam.h> #include <linux/platform_device.h>

-#include "../ecam.h" - static int gen_pci_parse_request_of_pci_ranges(struct device *dev, struct list_head *resources, struct resource **bus_range) { diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c index 6eaceab..f0ca6de 100644 --- a/drivers/pci/host/pci-host-generic.c +++ b/drivers/pci/host/pci-host-generic.c @@ -23,10 +23,9 @@ #include <linux/module.h> #include <linux/of_address.h> #include <linux/of_pci.h> +#include <linux/pci-ecam.h> #include <linux/platform_device.h>

-#include "../ecam.h" - static struct pci_ecam_ops gen_pci_cfg_cam_bus_ops = { .bus_shift = 16, .pci_ops = { diff --git a/drivers/pci/host/pci-thunder-ecam.c b/drivers/pci/host/pci-thunder-ecam.c index 540d030..a9fc1c9 100644 --- a/drivers/pci/host/pci-thunder-ecam.c +++ b/drivers/pci/host/pci-thunder-ecam.c @@ -11,10 +11,9 @@ #include <linux/ioport.h> #include <linux/of_pci.h> #include <linux/of.h> +#include <linux/pci-ecam.h> #include <linux/platform_device.h>

-#include "../ecam.h" - static void set_val(u32 v, int where, int size, u32 *val) { int shift = (where & 3) * 8; diff --git a/drivers/pci/host/pci-thunder-pem.c b/drivers/pci/host/pci-thunder-pem.c index 9b8ab94..5020d3d 100644 --- a/drivers/pci/host/pci-thunder-pem.c +++ b/drivers/pci/host/pci-thunder-pem.c @@ -18,10 +18,9 @@ #include <linux/module.h> #include <linux/of_address.h> #include <linux/of_pci.h> +#include <linux/pci-ecam.h> #include <linux/platform_device.h>

-#include "../ecam.h" - #define PEM_CFG_WR 0x28 #define PEM_CFG_RD 0x30

diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h new file mode 100644 index 0000000..9878beb --- /dev/null +++ b/include/linux/pci-ecam.h @@ -0,0 +1,67 @@ +/* + * Copyright 2016 Broadcom + * + * 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 DRIVERS_PCI_ECAM_H +#define DRIVERS_PCI_ECAM_H + +#include <linux/kernel.h> +#include <linux/platform_device.h> + +/* + * struct to hold pci ops and bus shift of the config window + * for a PCI controller. + */ +struct pci_config_window; +struct pci_ecam_ops { + unsigned int bus_shift; + struct pci_ops pci_ops; + int (*init)(struct device *, + struct pci_config_window *); +}; + +/* + * struct to hold the mappings of a config space window. This + * is expected to be used as sysdata for PCI controllers that + * use ECAM. + */ +struct pci_config_window { + struct resource res; + struct resource busr; + void *priv; + struct pci_ecam_ops *ops; + union { + void __iomem *win; /* 64-bit single mapping */ + void __iomem **winp; /* 32-bit per-bus mapping */ + }; +}; + +/* create and free pci_config_window */ +struct pci_config_window *pci_ecam_create(struct device *dev, + struct resource *cfgres, struct resource *busr, + struct pci_ecam_ops *ops); +void pci_ecam_free(struct pci_config_window *cfg); + +/* map_bus when ->sysdata is an instance of pci_config_window */ +void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn, + int where); +/* default ECAM ops */ +extern struct pci_ecam_ops pci_generic_ecam_ops; + +#ifdef CONFIG_PCI_HOST_GENERIC +/* for DT-based PCI controllers that support ECAM */ +int pci_host_common_probe(struct platform_device *pdev, + struct pci_ecam_ops *ops); +#endif +#endif

From: Sinan Kaya okaya@codeaurora.org

We need to release I/O resources so that the same I/O resources can be allocated again in pci_remap_iospace(), like in PCI hotplug removal scenario. Therefore implement new pci_unmap_iospace() call which unmaps I/O space as the symmetry to pci_remap_iospace().

Signed-off-by: Sinan Kaya okaya@codeaurora.org Signed-off-by: Tomasz Nowicki tn@semihalf.com Acked-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com --- drivers/pci/pci.c | 18 ++++++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 19 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index c8b4dbd..eb431b5 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -25,6 +25,7 @@ #include <linux/device.h> #include <linux/pm_runtime.h> #include <linux/pci_hotplug.h> +#include <linux/vmalloc.h> #include <asm/setup.h> #include <linux/aer.h> #include "pci.h" @@ -3165,6 +3166,23 @@ int __weak pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) #endif }

+/** + * pci_unmap_iospace - Unmap the memory mapped I/O space + * @res: resource to be unmapped + * + * Unmap the CPU virtual address @res from virtual address space. + * Only architectures that have memory mapped IO functions defined + * (and the PCI_IOBASE value defined) should call this function. + */ +void pci_unmap_iospace(struct resource *res) +{ +#if defined(PCI_IOBASE) && defined(CONFIG_MMU) + unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start; + + unmap_kernel_range(vaddr, resource_size(res)); +#endif +} + static void __pci_set_master(struct pci_dev *dev, bool enable) { u16 old_cmd, cmd; diff --git a/include/linux/pci.h b/include/linux/pci.h index b67e4df..12349de 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1167,6 +1167,7 @@ int pci_register_io_range(phys_addr_t addr, resource_size_t size); unsigned long pci_address_to_pio(phys_addr_t addr); phys_addr_t pci_pio_to_address(unsigned long pio); int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr); +void pci_unmap_iospace(struct resource *res);

static inline pci_bus_addr_t pci_bus_address(struct pci_dev *pdev, int bar) {

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; + } + + 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

pci_bus_find_domain_nr() retrieves the host bridge domain number in a DT specific way. Factor our pci_bus_find_domain_nr() in a separate DT function (ie of_pci_bus_find_domain_nr()) so that DT code is self contained, paving the way for retrieving domain number in pci_bus_find_domain_nr() with additional firmware methods (ie ACPI).

Signed-off-by: Tomasz Nowicki tn@semihalf.com --- drivers/pci/pci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b9a7833..327828d 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4941,7 +4941,7 @@ int pci_get_new_domain_nr(void) }

#ifdef CONFIG_PCI_DOMAINS_GENERIC -int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent) +static int of_pci_bus_find_domain_nr(struct device *parent) { static int use_dt_domains = -1; int domain = -1; @@ -4987,6 +4987,11 @@ int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)

return domain; } + +int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent) +{ + return of_pci_bus_find_domain_nr(parent); +} #endif #endif

To enable PCI legacy IRQs on platforms booting with ACPI, arch code should include ACPI specific callbacks that parse and set-up the device IRQ number, equivalent to the DT boot path. Owing to the current ACPI core scan handlers implementation, ACPI PCI legacy IRQs bindings cannot be parsed at device add time, since that would trigger ACPI scan handlers ordering issues depending on how the ACPI tables are defined.

To solve this problem and consolidate FW PCI legacy IRQs parsing in one single pcibios callback (pending final removal), this patch moves DT PCI IRQ parsing to the pcibios_alloc_irq() callback (called by PCI core code at device probe time) and adds ACPI PCI legacy IRQs parsing to the same callback too, so that FW PCI legacy IRQs parsing is confined in one single arch callback that can be easily removed when code parsing PCI legacy IRQs is consolidated and moved to core PCI code.

Signed-off-by: Tomasz Nowicki tn@semihalf.com Suggested-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com --- arch/arm64/kernel/pci.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index d5d3d26..b3b8a2c 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -51,11 +51,16 @@ int pcibios_enable_device(struct pci_dev *dev, int mask) }

/* - * Try to assign the IRQ number from DT when adding a new device + * Try to assign the IRQ number when probing a new device */ -int pcibios_add_device(struct pci_dev *dev) +int pcibios_alloc_irq(struct pci_dev *dev) { - dev->irq = of_irq_parse_and_map_pci(dev, 0, 0); + if (acpi_disabled) + dev->irq = of_irq_parse_and_map_pci(dev, 0, 0); +#ifdef CONFIG_ACPI + else + return acpi_pci_irq_enable(dev); +#endif

return 0; }

Implement pci_acpi_scan_root and other arch-specific call so that ARM64 can start using ACPI to setup and enumerate PCI buses.

Prior to buses enumeration the pci_acpi_scan_root() implementation looks for configuration space start address (obtained through ACPI _CBA method or MCFG interface). If succeed, it uses ECAM library to create new mapping. Then it attaches generic ECAM ops (pci_generic_ecam_ops) which are used for accessing configuration space later on.

On ARM64, we need to use generic domains (CONFIG_PCI_DOMAINS_GENERIC). In order to achieve that for ACPI case implement acpi_pci_bus_find_domain_nr() body so that it retrieves pci_config_window structure from bus sysdata and eventually gets domain number from acpi_pci_root structure.

ACPI requires to run acpi_pci_{add|remove}_bus while new PCI bus is created. This allows to do some ACPI-specific additional configuration, like PCI hotplug slot enumeration. In order to fulfill these requirements, we implement arch-specific pcibios_{add|remove}_bus calls and call acpi_pci_{add|remove}_bus from there.

Signed-off-by: Tomasz Nowicki tn@semihalf.com Signed-off-by: Jayachandran C jchandra@broadcom.com Reviewed-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com --- arch/arm64/Kconfig | 2 + arch/arm64/kernel/pci.c | 116 ++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 115 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 5a0a691..4806cde 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -3,6 +3,7 @@ config ARM64 select ACPI_CCA_REQUIRED if ACPI select ACPI_GENERIC_GSI if ACPI select ACPI_REDUCED_HARDWARE_ONLY if ACPI + select ACPI_MCFG if ACPI select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE select ARCH_HAS_ELF_RANDOMIZE @@ -96,6 +97,7 @@ config ARM64 select OF_EARLY_FLATTREE select OF_NUMA if NUMA && OF select OF_RESERVED_MEM + select PCI_ECAM if ACPI select PERF_USE_VMALLOC select POWER_RESET select POWER_SUPPLY diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index 328f857..94cd43c 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -18,6 +18,8 @@ #include <linux/of_pci.h> #include <linux/of_platform.h> #include <linux/pci.h> +#include <linux/pci-acpi.h> +#include <linux/pci-ecam.h> #include <linux/slab.h>

/* @@ -100,15 +102,123 @@ EXPORT_SYMBOL(pcibus_to_node);

#ifdef CONFIG_ACPI

+struct acpi_pci_generic_root_info { + struct acpi_pci_root_info common; + struct pci_config_window *cfg; /* config space mapping */ +}; + int acpi_pci_bus_find_domain_nr(struct pci_bus *bus) { + struct pci_config_window *cfg = bus->sysdata; + struct acpi_device *adev = to_acpi_device(cfg->parent); + struct acpi_pci_root *root = acpi_driver_data(adev); + + return root->segment; +} + +int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) +{ + if (!acpi_disabled) { + struct pci_config_window *cfg = bridge->bus->sysdata; + struct acpi_device *adev = to_acpi_device(cfg->parent); + ACPI_COMPANION_SET(&bridge->dev, adev); + } + return 0; }

-/* Root bridge scanning */ +/* + * Lookup the bus range for the domain in MCFG, and set up config space + * mapping. + */ +static struct pci_config_window * +pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root) +{ + struct resource *bus_res = &root->secondary; + u16 seg = root->segment; + struct pci_config_window *cfg; + struct resource cfgres; + unsigned int bsz; + + /* Use address from _CBA if present, otherwise lookup MCFG */ + if (!root->mcfg_addr) + root->mcfg_addr = pci_mcfg_lookup(seg, bus_res); + + if (!root->mcfg_addr) { + dev_err(&root->device->dev, "%04x:%pR ECAM region not found\n", + seg, bus_res); + return NULL; + } + + bsz = 1 << pci_generic_ecam_ops.bus_shift; + cfgres.start = root->mcfg_addr + bus_res->start * bsz; + cfgres.end = cfgres.start + resource_size(bus_res) * bsz - 1; + cfgres.flags = IORESOURCE_MEM; + cfg = pci_ecam_create(&root->device->dev, &cfgres, bus_res, + &pci_generic_ecam_ops); + if (IS_ERR(cfg)) { + dev_err(&root->device->dev, "%04x:%pR error %ld mapping ECAM\n", + seg, bus_res, PTR_ERR(cfg)); + return NULL; + } + + return cfg; +} + +/* release_info: free resources allocated by init_info */ +static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci) +{ + struct acpi_pci_generic_root_info *ri; + + ri = container_of(ci, struct acpi_pci_generic_root_info, common); + pci_ecam_free(ri->cfg); + kfree(ri); +} + +static struct acpi_pci_root_ops acpi_pci_root_ops = { + .release_info = pci_acpi_generic_release_info, +}; + +/* Interface called from ACPI code to setup PCI host controller */ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) { - /* TODO: Should be revisited when implementing PCI on ACPI */ - return NULL; + int node = acpi_get_node(root->device->handle); + struct acpi_pci_generic_root_info *ri; + struct pci_bus *bus, *child; + + ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node); + if (!ri) + return NULL; + + ri->cfg = pci_acpi_setup_ecam_mapping(root); + if (!ri->cfg) { + kfree(ri); + return NULL; + } + + acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops; + bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common, + ri->cfg); + if (!bus) + return NULL; + + pci_bus_size_bridges(bus); + pci_bus_assign_resources(bus); + + list_for_each_entry(child, &bus->children, node) + pcie_bus_configure_settings(child); + + return bus; +} + +void pcibios_add_bus(struct pci_bus *bus) +{ + acpi_pci_add_bus(bus); } + +void pcibios_remove_bus(struct pci_bus *bus) +{ + acpi_pci_remove_bus(bus); +} + #endif

On Fri, Jun 10, 2016 at 09:55:15PM +0200, Tomasz Nowicki wrote:

pci_bus_find_domain_nr() retrieves the host bridge domain number in a DT specific way. Factor our pci_bus_find_domain_nr() in a separate DT

s/our/out

function (ie of_pci_bus_find_domain_nr()) so that DT code is self contained, paving the way for retrieving domain number in pci_bus_find_domain_nr() with additional firmware methods (ie ACPI).

Signed-off-by: Tomasz Nowicki tn@semihalf.com

drivers/pci/pci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)

Reviewed-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b9a7833..327828d 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4941,7 +4941,7 @@ int pci_get_new_domain_nr(void) } #ifdef CONFIG_PCI_DOMAINS_GENERIC -int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent) +static int of_pci_bus_find_domain_nr(struct device *parent) { static int use_dt_domains = -1; int domain = -1; @@ -4987,6 +4987,11 @@ int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent) return domain; }

+int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent) +{

• return of_pci_bus_find_domain_nr(parent);

+} #endif #endif -- 1.9.1

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

On 11.06.2016 01:36, Bjorn Helgaas wrote:

On Fri, Jun 10, 2016 at 09:55:17PM +0200, Tomasz Nowicki wrote:

...

To enable PCI legacy IRQs on platforms booting with ACPI, arch code should include ACPI specific callbacks that parse and set-up the device IRQ number, equivalent to the DT boot path. Owing to the current ACPI core scan handlers implementation, ACPI PCI legacy IRQs bindings cannot be parsed at device add time, since that would trigger ACPI scan handlers ordering issues depending on how the ACPI tables are defined.

Uh, OK :) I can't figure out exactly what the problem is here -- I don't know where to look if I wanted to fix the scan handler ordering issues, and I don't know how I could tell if it would ever be safe to move this from driver probe-time back to device add-time.

I also notice that x86 and ia64 call acpi_pci_irq_enable() even later, when the driver *enables* the device. Is there a reason you didn't do it at the same time as x86 and ia64? This is another of those pcibios hooks that really don't do anything arch-specific, so I can imagine refactoring this somehow, someday.

Did we have this conversation before? It seems vaguely familiar, so I apologize if you already explained this once.

It stared with a scan handler ordering issue, please see: https://lists.linaro.org/pipermail/linaro-acpi/2015-October/005944.html hence we decided to postpone ACPI legacy IRQs parsing. We also decided to keep ACPI and DT legacy IRQs parsing all together as the candidate for further PCI legacy IRQs consolidation, please see [1]. This will allow us to remove it from here (as you pointed out is is not arch-specific at all).

I share Lorenzo's option. We could put this to pcibios_enable_device instead of pcibios_alloc_irq but since ACPI and DT code is in one call we wanted to avoid regressions on PCI host controllers that do not call pci_fixup_irqs(), but rely on the legacy IRQ routing to be done in arm64 pcibios_add_device().

[1] http://www.spinics.net/lists/linux-pci/msg45950.html

Thanks, Tomasz

...

To solve this problem and consolidate FW PCI legacy IRQs parsing in one single pcibios callback (pending final removal), this patch moves DT PCI IRQ parsing to the pcibios_alloc_irq() callback (called by PCI core code at device probe time) and adds ACPI PCI legacy IRQs parsing to the same callback too, so that FW PCI legacy IRQs parsing is confined in one single arch callback that can be easily removed when code parsing PCI legacy IRQs is consolidated and moved to core PCI code.

Signed-off-by: Tomasz Nowicki tn@semihalf.com Suggested-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com

---

arch/arm64/kernel/pci.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index d5d3d26..b3b8a2c 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -51,11 +51,16 @@ int pcibios_enable_device(struct pci_dev *dev, int mask) }

/*

• • Try to assign the IRQ number from DT when adding a new device

• • Try to assign the IRQ number when probing a new device
  */

-int pcibios_add_device(struct pci_dev *dev) +int pcibios_alloc_irq(struct pci_dev *dev) {

• dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);

• if (acpi_disabled)

• dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
  

+#ifdef CONFIG_ACPI

• else

• return acpi_pci_irq_enable(dev);
  

+#endif

return 0; } -- 1.9.1

On Mon, Jun 13, 2016 at 11:40:05AM +0100, Lorenzo Pieralisi wrote:

On Fri, Jun 10, 2016 at 06:36:12PM -0500, Bjorn Helgaas wrote:

...

On Fri, Jun 10, 2016 at 09:55:17PM +0200, Tomasz Nowicki wrote:

...

To enable PCI legacy IRQs on platforms booting with ACPI, arch code should include ACPI specific callbacks that parse and set-up the device IRQ number, equivalent to the DT boot path. Owing to the current ACPI core scan handlers implementation, ACPI PCI legacy IRQs bindings cannot be parsed at device add time, since that would trigger ACPI scan handlers ordering issues depending on how the ACPI tables are defined.

Uh, OK :) I can't figure out exactly what the problem is here -- I don't know where to look if I wanted to fix the scan handler ordering issues, and I don't know how I could tell if it would ever be safe to move this from driver probe-time back to device add-time.

Right, the commit log could have been more informative.

pcibios_add_device() was added in:

commit d1e6dc91b532 ("arm64: Add architectural support for PCI")

whose commit log does not specify why legacy IRQ parsing should be done at pcibios_add_device() either, so honestly we had to do with the information we have at hand.

Because at that time (September 2014) there was no pcibios_alloc_irq() (added June 2015 by commit 890e4847587fcf) and after that nobody bothered to update the arm64 code to make use of the new API.

Best regards, Liviu

...

I also notice that x86 and ia64 call acpi_pci_irq_enable() even later, when the driver *enables* the device. Is there a reason you didn't do it at the same time as x86 and ia64? This is another of those pcibios hooks that really don't do anything arch-specific, so I can imagine refactoring this somehow, someday.

Yes, with [1], that was the goal, that stopped because [1] does not work on x86.

Only DT platform(s) affected by this change are all platforms relying on drivers/pci/host/pci-xgene.c (others rely on pci_fixup_irqs() that should be removed too), if on those platforms probing IRQs at device enable time works ok I can update this patch (it can be done through [1] once we figure out what to do with it on x86) and move the IRQ set-up at pcibios_enable_device() time.

@Duc: any feedback on this ?

Thanks, Lorenzo

[1] http://www.spinics.net/lists/linux-pci/msg45950.html

...

Did we have this conversation before? It seems vaguely familiar, so I apologize if you already explained this once.

...

To solve this problem and consolidate FW PCI legacy IRQs parsing in one single pcibios callback (pending final removal), this patch moves DT PCI IRQ parsing to the pcibios_alloc_irq() callback (called by PCI core code at device probe time) and adds ACPI PCI legacy IRQs parsing to the same callback too, so that FW PCI legacy IRQs parsing is confined in one single arch callback that can be easily removed when code parsing PCI legacy IRQs is consolidated and moved to core PCI code.

Signed-off-by: Tomasz Nowicki tn@semihalf.com Suggested-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com

---

arch/arm64/kernel/pci.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index d5d3d26..b3b8a2c 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -51,11 +51,16 @@ int pcibios_enable_device(struct pci_dev *dev, int mask) } /*

• • Try to assign the IRQ number from DT when adding a new device

• • Try to assign the IRQ number when probing a new device
  */

-int pcibios_add_device(struct pci_dev *dev) +int pcibios_alloc_irq(struct pci_dev *dev) {

• dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);

• if (acpi_disabled)

• dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
  

+#ifdef CONFIG_ACPI

• else

• return acpi_pci_irq_enable(dev);
  

+#endif return 0; } -- 1.9.1

On Mon, Jun 13, 2016 at 01:01:35PM -0700, Duc Dang wrote:

On Mon, Jun 13, 2016 at 3:40 AM, Lorenzo Pieralisi lorenzo.pieralisi@arm.com wrote:

...

On Fri, Jun 10, 2016 at 06:36:12PM -0500, Bjorn Helgaas wrote:

...

On Fri, Jun 10, 2016 at 09:55:17PM +0200, Tomasz Nowicki wrote:

...

To enable PCI legacy IRQs on platforms booting with ACPI, arch code should include ACPI specific callbacks that parse and set-up the device IRQ number, equivalent to the DT boot path. Owing to the current ACPI core scan handlers implementation, ACPI PCI legacy IRQs bindings cannot be parsed at device add time, since that would trigger ACPI scan handlers ordering issues depending on how the ACPI tables are defined.

Uh, OK :) I can't figure out exactly what the problem is here -- I don't know where to look if I wanted to fix the scan handler ordering issues, and I don't know how I could tell if it would ever be safe to move this from driver probe-time back to device add-time.

Right, the commit log could have been more informative.

pcibios_add_device() was added in:

commit d1e6dc91b532 ("arm64: Add architectural support for PCI")

whose commit log does not specify why legacy IRQ parsing should be done at pcibios_add_device() either, so honestly we had to do with the information we have at hand.

...

I also notice that x86 and ia64 call acpi_pci_irq_enable() even later, when the driver *enables* the device. Is there a reason you didn't do it at the same time as x86 and ia64? This is another of those pcibios hooks that really don't do anything arch-specific, so I can imagine refactoring this somehow, someday.

Yes, with [1], that was the goal, that stopped because [1] does not work on x86.

Only DT platform(s) affected by this change are all platforms relying on drivers/pci/host/pci-xgene.c (others rely on pci_fixup_irqs() that should be removed too), if on those platforms probing IRQs at device enable time works ok I can update this patch (it can be done through [1] once we figure out what to do with it on x86) and move the IRQ set-up at pcibios_enable_device() time.

@Duc: any feedback on this ?

Hi Lorenzo,

The changes to add pcibios_alloc_irq works fine on X-Gene PCIe

I also tried to remove pcibios_alloc_irq and move its code into pcibios_enable_device after pci_enable_resource call and legacy IRQ also works.

Thank you, that was important to check.

Can you also point me to the discussion thread or some info. about the issue on x86 with [1]? I want to check if there is any more test case I need to verify.

http://marc.info/?l=linux-pci&m=145091187918297&w=2

I do not think there is much we can do, unless we convert pci_fixup_irqs as per [1] but keep x86 code as-is (for now), there is a way to do it it is just a matter of taking Matt's series and refactor it, there are potential problems (not on xgene, but on other ARM platforms where the IRQ legacy routing is done through pci_fixup_irqs()).

Lorenzo

Regards, Duc Dang.

...

Thanks, Lorenzo

[1] http://www.spinics.net/lists/linux-pci/msg45950.html

...

Did we have this conversation before? It seems vaguely familiar, so I apologize if you already explained this once.

...

To solve this problem and consolidate FW PCI legacy IRQs parsing in one single pcibios callback (pending final removal), this patch moves DT PCI IRQ parsing to the pcibios_alloc_irq() callback (called by PCI core code at device probe time) and adds ACPI PCI legacy IRQs parsing to the same callback too, so that FW PCI legacy IRQs parsing is confined in one single arch callback that can be easily removed when code parsing PCI legacy IRQs is consolidated and moved to core PCI code.

Signed-off-by: Tomasz Nowicki tn@semihalf.com Suggested-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com

---

arch/arm64/kernel/pci.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index d5d3d26..b3b8a2c 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -51,11 +51,16 @@ int pcibios_enable_device(struct pci_dev *dev, int mask) }

/*

• • Try to assign the IRQ number from DT when adding a new device

• • Try to assign the IRQ number when probing a new device
  */

-int pcibios_add_device(struct pci_dev *dev) +int pcibios_alloc_irq(struct pci_dev *dev) {

• dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);

• if (acpi_disabled)

•       dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
  

+#ifdef CONFIG_ACPI

• else

•       return acpi_pci_irq_enable(dev);
  

+#endif

return 0;

}

1.9.1

Hi Bjorn,

On 23.11.2016 00:13, Bjorn Helgaas wrote:

Hi Tomasz,

On Fri, Jun 10, 2016 at 09:55:19PM +0200, Tomasz Nowicki wrote:

...

Implement pci_acpi_scan_root and other arch-specific call so that ARM64 can start using ACPI to setup and enumerate PCI buses.

Prior to buses enumeration the pci_acpi_scan_root() implementation looks for configuration space start address (obtained through ACPI _CBA method or MCFG interface). If succeed, it uses ECAM library to create new mapping. Then it attaches generic ECAM ops (pci_generic_ecam_ops) which are used for accessing configuration space later on. ...

...

+static struct acpi_pci_root_ops acpi_pci_root_ops = {

• .release_info = pci_acpi_generic_release_info,

+};

+/* Interface called from ACPI code to setup PCI host controller */ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) {

• /* TODO: Should be revisited when implementing PCI on ACPI */
• return NULL;

• int node = acpi_get_node(root->device->handle);
• struct acpi_pci_generic_root_info *ri;
• struct pci_bus *bus, *child;
• ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
• if (!ri)

• return NULL;
  

• ri->cfg = pci_acpi_setup_ecam_mapping(root);
• if (!ri->cfg) {

• kfree(ri);
  

• return NULL;
  

• }
• acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;

This has already been merged, but this isn't right, is it? We're writing a host controller-specific pointer into the single system-wide acpi_pci_root_ops, then passing it on to acpi_pci_root_create().

Today, I think ri->cfg->ops->pci_ops is always &pci_generic_ecam_ops, from this path:

ri->cfg = pci_acpi_setup_ecam_mapping cfg = pci_ecam_create(..., &pci_generic_ecam_ops) cfg = kzalloc(...) cfg->ops = ops # &pci_generic_ecam_ops

But we're about to merge the ECAM quirks series, which will mean it may not be &pci_generic_ecam_ops. Even apart from the ECAM quirks, we should avoid this pattern of putting device-specific info in a single shared structure because it's too difficult to verify that it's correct.

Well spotted. I agree, we need to fix this. How about this: diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index fb439c7..31c0e1c 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -152,33 +152,35 @@ static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)

ri = container_of(ci, struct acpi_pci_generic_root_info, common); pci_ecam_free(ri->cfg); + kfree(ci->ops); kfree(ri); }

-static struct acpi_pci_root_ops acpi_pci_root_ops = { - .release_info = pci_acpi_generic_release_info, -}; - /* Interface called from ACPI code to setup PCI host controller */ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) { int node = acpi_get_node(root->device->handle); struct acpi_pci_generic_root_info *ri; struct pci_bus *bus, *child; + struct acpi_pci_root_ops *root_ops;

ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node); if (!ri) return NULL;

+ root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node); + if (!root_ops) + return NULL; + ri->cfg = pci_acpi_setup_ecam_mapping(root); if (!ri->cfg) { kfree(ri); + kfree(root_ops); return NULL; }

- acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops; - bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common, - ri->cfg); + root_ops->release_info = pci_acpi_generic_release_info; + root_ops->pci_ops = &ri->cfg->ops->pci_ops; + bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg); if (!bus) return NULL;

Of course, this should be the part of ECAM quirks core patches.

The other option we have is to remove "struct pci_ops *pci_ops;" from acpi_pci_root_ops structure and pass struct pci_ops as an extra argument to acpi_pci_root_create(). What do you think?

Thanks, Tomasz

On 23.11.2016 19:22, Bjorn Helgaas wrote:

On Wed, Nov 23, 2016 at 12:21:03PM +0100, Tomasz Nowicki wrote:

...

Hi Bjorn,

On 23.11.2016 00:13, Bjorn Helgaas wrote:

...

Hi Tomasz,

On Fri, Jun 10, 2016 at 09:55:19PM +0200, Tomasz Nowicki wrote:

...

Implement pci_acpi_scan_root and other arch-specific call so that ARM64 can start using ACPI to setup and enumerate PCI buses.

Prior to buses enumeration the pci_acpi_scan_root() implementation looks for configuration space start address (obtained through ACPI _CBA method or MCFG interface). If succeed, it uses ECAM library to create new mapping. Then it attaches generic ECAM ops (pci_generic_ecam_ops) which are used for accessing configuration space later on. ...

...

+static struct acpi_pci_root_ops acpi_pci_root_ops = {

• .release_info = pci_acpi_generic_release_info,

+};

+/* Interface called from ACPI code to setup PCI host controller */ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) {

• /* TODO: Should be revisited when implementing PCI on ACPI */
• return NULL;

• int node = acpi_get_node(root->device->handle);
• struct acpi_pci_generic_root_info *ri;
• struct pci_bus *bus, *child;
• ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
• if (!ri)

• return NULL;
  

• ri->cfg = pci_acpi_setup_ecam_mapping(root);
• if (!ri->cfg) {

• kfree(ri);
  

• return NULL;
  

• }
• acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;

This has already been merged, but this isn't right, is it? We're writing a host controller-specific pointer into the single system-wide acpi_pci_root_ops, then passing it on to acpi_pci_root_create().

Today, I think ri->cfg->ops->pci_ops is always &pci_generic_ecam_ops, from this path:

ri->cfg = pci_acpi_setup_ecam_mapping cfg = pci_ecam_create(..., &pci_generic_ecam_ops) cfg = kzalloc(...) cfg->ops = ops # &pci_generic_ecam_ops

But we're about to merge the ECAM quirks series, which will mean it may not be &pci_generic_ecam_ops. Even apart from the ECAM quirks, we should avoid this pattern of putting device-specific info in a single shared structure because it's too difficult to verify that it's correct.

Well spotted. I agree, we need to fix this. How about this: diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index fb439c7..31c0e1c 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -152,33 +152,35 @@ static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)

    ri = container_of(ci, struct acpi_pci_generic_root_info, common);
    pci_ecam_free(ri->cfg);

•   kfree(ci->ops);
    kfree(ri);
  

}

-static struct acpi_pci_root_ops acpi_pci_root_ops = {

•   .release_info = pci_acpi_generic_release_info,
  

-};

/* Interface called from ACPI code to setup PCI host controller */ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) { int node = acpi_get_node(root->device->handle); struct acpi_pci_generic_root_info *ri; struct pci_bus *bus, *child;

•   struct acpi_pci_root_ops *root_ops;
  
    ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
    if (!ri)
            return NULL;
  
  

•   root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node);
  

•   if (!root_ops)
  

•           return NULL;
  

•   ri->cfg = pci_acpi_setup_ecam_mapping(root);
    if (!ri->cfg) {
            kfree(ri);
  

•           kfree(root_ops);
            return NULL;
    }
  
  

•   acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
  

•   bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
  

•                              ri->cfg);
  

•   root_ops->release_info = pci_acpi_generic_release_info;
  

•   root_ops->pci_ops = &ri->cfg->ops->pci_ops;
  

•   bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
    if (!bus)
            return NULL;
  
  

Of course, this should be the part of ECAM quirks core patches.

The other option we have is to remove "struct pci_ops *pci_ops;" from acpi_pci_root_ops structure and pass struct pci_ops as an extra argument to acpi_pci_root_create(). What do you think?

I think your patch above is fine and avoids the need to change the x86 and ia64 code. Would you mind packaging this up with a changelog and signed-off-by? I can take care of putting it in the ECAM series.

Sure, I have just sent the patch in replay to ECAM quirks V6 patch set.

Let us know when you update your branch so we base our quirks on it.

Thanks, Tomasz