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 <tn@xxxxxxxxxxxx>
---
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 <tomasz.nowicki@xxxxxxxxxx>
+ *
+ * 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 <tomasz.nowicki@xxxxxxxxxx>
+ *
+ * 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
--
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