IORT shows representation of IO topology for ARM based systems. It describes how various components are connected together on parent-child basis e.g. PCI RC -> SMMU -> ITS.
Initial support allows to: - register ITS MSI chip along with ITS translation ID and domain token - find registered domain token based on ITS translation ID - find registered domain token corresponding to given PCI device - find PCI device DeviceID based on its RequesterID Additional features like: - devices to SMMU binding - finding platform device DeviceID based on its RequesterID will be added in next series. Signed-off-by: Tomasz Nowicki <[email protected]> --- drivers/acpi/Kconfig | 3 + drivers/acpi/Makefile | 1 + drivers/acpi/iort.c | 326 ++++++++++++++++++++++++++++++++++++++++++++++++ drivers/irqchip/Kconfig | 1 + include/linux/iort.h | 38 ++++++ 5 files changed, 369 insertions(+) create mode 100644 drivers/acpi/iort.c create mode 100644 include/linux/iort.h diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 5d1015c..8d2b2bd 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -57,6 +57,9 @@ config ACPI_SYSTEM_POWER_STATES_SUPPORT config ACPI_CCA_REQUIRED bool +config IORT_TABLE + bool + config ACPI_SLEEP bool depends on SUSPEND || HIBERNATION diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index b5e7cd8..962f98e 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -78,6 +78,7 @@ obj-$(CONFIG_ACPI_HED) += hed.o obj-$(CONFIG_ACPI_EC_DEBUGFS) += ec_sys.o obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o obj-$(CONFIG_ACPI_BGRT) += bgrt.o +obj-$(CONFIG_IORT_TABLE) += iort.o # processor has its own "processor." module_param namespace processor-y := processor_driver.o diff --git a/drivers/acpi/iort.c b/drivers/acpi/iort.c new file mode 100644 index 0000000..13efc5f --- /dev/null +++ b/drivers/acpi/iort.c @@ -0,0 +1,326 @@ +/* + * Copyright (C) 2015, Linaro Ltd. + * Author: Tomasz Nowicki <[email protected]> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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 for + * more details. + * + * This file implements early detection/parsing of I/O mapping + * reported to OS through firmware via I/O Remapping Table (IORT) + * IORT document number: ARM DEN 0049A + */ + +#define pr_fmt(fmt) "ACPI: IORT: " fmt + +#include <linux/export.h> +#include <linux/iort.h> +#include <linux/irqdomain.h> +#include <linux/kernel.h> +#include <linux/pci.h> + +struct iort_its_msi_chip { + struct list_head list; + struct fwnode_handle *fw_node; + u32 translation_id; +}; + +typedef acpi_status (*iort_find_node_callback) + (struct acpi_iort_node *node, void *context); + +/* Root pointer to the mapped IORT table */ +static struct acpi_table_header *iort_table; + +static LIST_HEAD(iort_msi_chip_list); + +/** + * iort_register_domain_token() - register domain token and related ITS ID + * to the list from where we can get it back + * later on. + * @translation_id: ITS ID + * @token: domain token + * + * Returns: 0 on success, -ENOMEM if not memory when allocating list element. + */ +int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node) +{ + struct iort_its_msi_chip *its_msi_chip; + + its_msi_chip = kzalloc(sizeof(*its_msi_chip), GFP_KERNEL); + if (!its_msi_chip) + return -ENOMEM; + + its_msi_chip->fw_node = fw_node; + its_msi_chip->translation_id = trans_id; + + list_add(&its_msi_chip->list, &iort_msi_chip_list); + return 0; +} + +/** + * iort_find_its_domain_token() - find domain token based on given ITS ID. + * @translation_id: ITS ID + * + * Returns: domain token when find on the list, NULL otherwise. + */ +struct fwnode_handle *iort_find_its_domain_token(int trans_id) +{ + struct iort_its_msi_chip *its_msi_chip; + + list_for_each_entry(its_msi_chip, &iort_msi_chip_list, list) { + if (its_msi_chip->translation_id == trans_id) + return its_msi_chip->fw_node; + } + + return NULL; +} + +static struct acpi_iort_node * +iort_scan_node(enum acpi_iort_node_type type, + iort_find_node_callback callback, void *context) +{ + struct acpi_iort_node *iort_node, *iort_end; + struct acpi_table_iort *iort; + int i; + + if (!iort_table) + return NULL; + + /* + * iort_table and iort both point to the start of IORT table, but + * have different struct types + */ + iort = (struct acpi_table_iort *)iort_table; + + /* Get the first IORT node */ + iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort, + iort->node_offset); + iort_end = ACPI_ADD_PTR(struct acpi_iort_node, iort_table, + iort_table->length); + + for (i = 0; i < iort->node_count; i++) { + if (iort_node >= iort_end) { + pr_err("iort node pointer overflows, bad table\n"); + return NULL; + } + + if (iort_node->type == type) { + if (ACPI_SUCCESS(callback(iort_node, context))) + return iort_node; + } + + iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node, + iort_node->length); + } + + return NULL; +} + +static struct acpi_iort_node *iort_find_parent_node(struct acpi_iort_node *node) +{ + struct acpi_iort_id_mapping *id; + + if (!node || !node->mapping_offset || !node->mapping_count) + return NULL; + + id = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node, + node->mapping_offset); + /* Firmware bug! */ + if (!id->output_reference) { + pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n", + node, node->type); + return NULL; + } + + node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table, + id->output_reference); + return node; +} + +static acpi_status +iort_find_dev_callback(struct acpi_iort_node *node, void *context) +{ + struct acpi_iort_root_complex *pci_rc; + struct device *dev = context; + struct pci_bus *bus; + + switch (node->type) { + case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: + bus = to_pci_bus(dev); + pci_rc = (struct acpi_iort_root_complex *)node->node_data; + + /* + * It is assumed that PCI segment numbers have a one-to-one + * mapping with root complexes. Each segment number can + * represent only one root complex. + */ + if (pci_rc->pci_segment_number == pci_domain_nr(bus)) + return AE_OK; + + break; + } + + return AE_NOT_FOUND; +} + +/** + * iort_pci_find_its_id() - find the ITS identifier based on specified device. + * @dev: device + * @idx: index of the ITS identifier list + * @its_id: ITS identifier + * + * Returns: 0 on success, appropriate error value otherwise + */ +static int +iort_pci_find_its_id(struct device *dev, unsigned int idx, int *its_id) +{ + struct acpi_iort_its_group *its; + struct acpi_iort_node *node; + + node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX, + iort_find_dev_callback, dev); + if (!node) { + pr_err("can't find node related to %s device\n", dev_name(dev)); + return -ENXIO; + } + + /* Go upstream until find its parent ITS node */ + while (node->type != ACPI_IORT_NODE_ITS_GROUP) { + node = iort_find_parent_node(node); + if (!node) + return -ENXIO; + } + + /* Move to ITS specific data */ + its = (struct acpi_iort_its_group *)node->node_data; + if (idx > its->its_count) { + pr_err("requested ITS ID index [%d] is greater than available ITS count [%d]\n", + idx, its->its_count); + return -ENXIO; + } + + *its_id = its->identifiers[idx]; + return 0; +} + + +/** + * iort_find_pci_domain_token() - find registered domain token related to + * PCI device + * @dev: device + * + * Returns: domain token on success, NULL otherwise + */ +struct fwnode_handle *iort_find_pci_domain_token(struct device *dev) +{ + static struct fwnode_handle *domain_handle; + int its_id; + + if (iort_pci_find_its_id(dev, 0, &its_id)) + return NULL; + + domain_handle = iort_find_its_domain_token(its_id); + if (!domain_handle) + return NULL; + + return domain_handle; +} + +static int +iort_translate_dev_to_devid(struct acpi_iort_node *node, u32 req_id, + u32 *dev_id) +{ + u32 curr_id = req_id; + + if (!node) + return -EINVAL; + + /* Go upstream */ + while (node->type != ACPI_IORT_NODE_ITS_GROUP) { + struct acpi_iort_id_mapping *id; + int i, found = 0; + + /* Exit when no mapping array */ + if (!node->mapping_offset || !node->mapping_count) + return -EINVAL; + + id = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node, + node->mapping_offset); + + for (i = 0, found = 0; i < node->mapping_count; i++, id++) { + /* + * Single mapping is not translation rule, + * lets move on for this case + */ + if (id->flags & ACPI_IORT_ID_SINGLE_MAPPING) + continue; + + if (curr_id < id->input_base || + (curr_id > id->input_base + id->id_count)) + continue; + + curr_id = id->output_base + (curr_id - id->input_base); + found = 1; + break; + } + + if (!found) + return -ENXIO; + + node = iort_find_parent_node(node); + if (!node) + return -ENXIO; + } + + *dev_id = curr_id; + return 0; +} + +/** + * iort_find_pci_id() - find PCI device ID based on requester ID + * @dev: device + * @req_id: requester ID + * @dev_id: device ID + * + * Returns: 0 on success, appropriate error value otherwise + */ +int iort_find_pci_id(struct pci_dev *pdev, u32 req_id, u32 *dev_id) +{ + struct pci_bus *bus = pdev->bus; + struct acpi_iort_node *node; + int err; + + node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX, + iort_find_dev_callback, &bus->dev); + if (!node) { + pr_err("can't find node related to %s device\n", + dev_name(&pdev->dev)); + return -ENXIO; + } + + err = iort_translate_dev_to_devid(node, req_id, dev_id); + return err; +} + +static int __init iort_table_detect(void) +{ + acpi_status status; + + if (acpi_disabled) + return -ENODEV; + + status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table); + if (ACPI_FAILURE(status)) { + const char *msg = acpi_format_exception(status); + pr_err("Failed to get table, %s\n", msg); + return -EINVAL; + } + + return 0; +} +arch_initcall(iort_table_detect); diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index 27b52c8..67a8da56 100644 --- a/drivers/irqchip/Kconfig +++ b/drivers/irqchip/Kconfig @@ -26,6 +26,7 @@ config ARM_GIC_V3 config ARM_GIC_V3_ITS bool select PCI_MSI_IRQ_DOMAIN + select IORT_TABLE if ACPI config ARM_NVIC bool diff --git a/include/linux/iort.h b/include/linux/iort.h new file mode 100644 index 0000000..783e8d6 --- /dev/null +++ b/include/linux/iort.h @@ -0,0 +1,38 @@ +/* + * Copyright (C) 2015, Linaro Ltd. + * Author: Tomasz Nowicki <[email protected]> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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 for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple + * Place - Suite 330, Boston, MA 02111-1307 USA. + */ + +#ifndef __IORT_H__ +#define __IORT_H__ + +#include <linux/acpi.h> + +#ifdef CONFIG_ACPI + +struct fwnode_handle; + +int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node); +struct fwnode_handle *iort_find_its_domain_token(int trans_id); +struct fwnode_handle *iort_find_pci_domain_token(struct device *dev); +int iort_find_pci_id(struct pci_dev *pdev, u32 req_id, u32 *dev_id); +#else /* CONFIG_ACPI */ +static inline int +iort_find_pci_id(struct pci_dev *pdev, u32 req_id, u32 *dev_id) +{ return -ENXIO; } +#endif /* CONFIG_ACPI */ + +#endif /* __IORT_H__ */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
