summaryrefslogtreecommitdiff
path: root/drivers/acpi/arm64
diff options
context:
space:
mode:
authorTomasz Nowicki <tn@semihalf.com>2016-09-12 21:54:20 +0300
committerMarc Zyngier <marc.zyngier@arm.com>2016-09-12 22:32:30 +0300
commit88ef16d888a094587b2ac77de60927df5da5d56d (patch)
treea15c57a32a81fd41efa2b0be1ea9492035dcc74f /drivers/acpi/arm64
parent89c59cca48f04ede7e63944418af1794a8e31da6 (diff)
downloadlinux-88ef16d888a094587b2ac77de60927df5da5d56d.tar.xz
ACPI: I/O Remapping Table (IORT) initial support
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. Also see IORT spec. http://infocenter.arm.com/help/topic/com.arm.doc.den0049b/DEN0049B_IO_Remapping_Table.pdf Initial support allows to detect IORT table presence and save its root pointer obtained through acpi_get_table(). The pointer validity depends on acpi_gbl_permanent_mmap because if acpi_gbl_permanent_mmap is not set while using IORT nodes we would dereference unmapped pointers. For the aforementioned reason call acpi_iort_init() from acpi_init() which guarantees acpi_gbl_permanent_mmap to be set at that point. Add generic helpers which are helpful for scanning and retrieving information from IORT table content. List of the most important helpers: - iort_find_dev_node() finds IORT node for a given device - iort_node_map_rid() maps device RID and returns IORT node which provides final translation IORT support is placed under drivers/acpi/arm64/ new directory due to its ARM64 specific nature. The code there is considered only for ARM64. The long term plan is to keep all ARM64 specific tables support in this place e.g. GTDT table. Signed-off-by: Tomasz Nowicki <tn@semihalf.com> Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'drivers/acpi/arm64')
-rw-r--r--drivers/acpi/arm64/Kconfig6
-rw-r--r--drivers/acpi/arm64/Makefile1
-rw-r--r--drivers/acpi/arm64/iort.c216
3 files changed, 223 insertions, 0 deletions
diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
new file mode 100644
index 000000000000..4616da4c15be
--- /dev/null
+++ b/drivers/acpi/arm64/Kconfig
@@ -0,0 +1,6 @@
+#
+# ACPI Configuration for ARM64
+#
+
+config ACPI_IORT
+ bool
diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
new file mode 100644
index 000000000000..72331f2ce0e9
--- /dev/null
+++ b/drivers/acpi/arm64/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_ACPI_IORT) += iort.o
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);
+ }
+}