diff options
Diffstat (limited to 'drivers/acpi/arm64/iort.c')
| -rw-r--r-- | drivers/acpi/arm64/iort.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c new file mode 100644 index 000000000000..5279a358924a --- /dev/null +++ b/drivers/acpi/arm64/iort.c @@ -0,0 +1,216 @@ +/* + * 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 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/acpi_iort.h> +#include <linux/kernel.h> +#include <linux/pci.h> + +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); +static DEFINE_SPINLOCK(iort_msi_chip_lock); + +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; + + /* Get the first IORT node */ + iort = (struct acpi_table_iort *)iort_table; + 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 (WARN_TAINT(iort_node >= iort_end, TAINT_FIRMWARE_WORKAROUND, + "IORT node pointer overflows, bad table!\n")) + return NULL; + + if (iort_node->type == type && + 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 acpi_status iort_match_node_callback(struct acpi_iort_node *node, + void *context) +{ + struct device *dev = context; + acpi_status status; + + if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT) { + struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL }; + struct acpi_device *adev = to_acpi_device_node(dev->fwnode); + struct acpi_iort_named_component *ncomp; + + if (!adev) { + status = AE_NOT_FOUND; + goto out; + } + + status = acpi_get_name(adev->handle, ACPI_FULL_PATHNAME, &buf); + if (ACPI_FAILURE(status)) { + dev_warn(dev, "Can't get device full path name\n"); + goto out; + } + + ncomp = (struct acpi_iort_named_component *)node->node_data; + status = !strcmp(ncomp->device_name, buf.pointer) ? + AE_OK : AE_NOT_FOUND; + acpi_os_free(buf.pointer); + } else if (node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) { + struct acpi_iort_root_complex *pci_rc; + struct pci_bus *bus; + + bus = to_pci_bus(dev); + pci_rc = (struct acpi_iort_root_complex *)node->node_data; + + /* + * It is assumed that PCI segment numbers maps one-to-one + * with root complexes. Each segment number can represent only + * one root complex. + */ + status = pci_rc->pci_segment_number == pci_domain_nr(bus) ? + AE_OK : AE_NOT_FOUND; + } else { + status = AE_NOT_FOUND; + } +out: + return status; +} + +static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in, + u32 *rid_out) +{ + /* Single mapping does not care for input id */ + if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) { + if (type == ACPI_IORT_NODE_NAMED_COMPONENT || + type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) { + *rid_out = map->output_base; + return 0; + } + + pr_warn(FW_BUG "[map %p] SINGLE MAPPING flag not allowed for node type %d, skipping ID map\n", + map, type); + return -ENXIO; + } + + if (rid_in < map->input_base || + (rid_in >= map->input_base + map->id_count)) + return -ENXIO; + + *rid_out = map->output_base + (rid_in - map->input_base); + return 0; +} + +static struct acpi_iort_node *iort_node_map_rid(struct acpi_iort_node *node, + u32 rid_in, u32 *rid_out, + u8 type) +{ + u32 rid = rid_in; + + /* Parse the ID mapping tree to find specified node type */ + while (node) { + struct acpi_iort_id_mapping *map; + int i; + + if (node->type == type) { + if (rid_out) + *rid_out = rid; + return node; + } + + if (!node->mapping_offset || !node->mapping_count) + goto fail_map; + + map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node, + node->mapping_offset); + + /* Firmware bug! */ + if (!map->output_reference) { + pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n", + node, node->type); + goto fail_map; + } + + /* Do the RID translation */ + for (i = 0; i < node->mapping_count; i++, map++) { + if (!iort_id_map(map, node->type, rid, &rid)) + break; + } + + if (i == node->mapping_count) + goto fail_map; + + node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table, + map->output_reference); + } + +fail_map: + /* Map input RID to output RID unchanged on mapping failure*/ + if (rid_out) + *rid_out = rid_in; + + return NULL; +} + +static struct acpi_iort_node *iort_find_dev_node(struct device *dev) +{ + struct pci_bus *pbus; + + if (!dev_is_pci(dev)) + return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT, + iort_match_node_callback, dev); + + /* Find a PCI root bus */ + pbus = to_pci_dev(dev)->bus; + while (!pci_is_root_bus(pbus)) + pbus = pbus->parent; + + return iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX, + iort_match_node_callback, &pbus->dev); +} + +void __init acpi_iort_init(void) +{ + acpi_status status; + + status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table); + if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { + const char *msg = acpi_format_exception(status); + pr_err("Failed to get table, %s\n", msg); + } +} |