380 lines
12 KiB
Diff
380 lines
12 KiB
Diff
From: Andreas Noever <andreas.noever@gmail.com>
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Date: Tue, 3 Jun 2014 22:04:07 +0200
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Subject: [10/31] thunderbolt: Add path setup code.
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Origin: https://git.kernel.org/linus/520b670216a15fb949e6ec6a1af9b5dd55d219c7
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A thunderbolt path is a unidirectional channel between two thunderbolt
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ports. Two such paths are needed to establish a pci tunnel.
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This patch introduces struct tb_path as well as a set of tb_path_*
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methods which are used to activate & deactivate paths.
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Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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---
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drivers/thunderbolt/Makefile | 2 +-
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drivers/thunderbolt/path.c | 215 +++++++++++++++++++++++++++++++++++++++++++
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drivers/thunderbolt/switch.c | 34 +++++++
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drivers/thunderbolt/tb.h | 62 +++++++++++++
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4 files changed, 312 insertions(+), 1 deletion(-)
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create mode 100644 drivers/thunderbolt/path.c
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diff --git a/drivers/thunderbolt/Makefile b/drivers/thunderbolt/Makefile
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index 617b314..3532f36 100644
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--- a/drivers/thunderbolt/Makefile
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+++ b/drivers/thunderbolt/Makefile
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@@ -1,3 +1,3 @@
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obj-${CONFIG_THUNDERBOLT} := thunderbolt.o
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-thunderbolt-objs := nhi.o ctl.o tb.o switch.o cap.o
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+thunderbolt-objs := nhi.o ctl.o tb.o switch.o cap.o path.o
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diff --git a/drivers/thunderbolt/path.c b/drivers/thunderbolt/path.c
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new file mode 100644
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index 0000000..8fcf8a7
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--- /dev/null
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+++ b/drivers/thunderbolt/path.c
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@@ -0,0 +1,215 @@
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+/*
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+ * Thunderbolt Cactus Ridge driver - path/tunnel functionality
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+ *
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+ * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
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+ */
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+
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+#include <linux/slab.h>
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+#include <linux/errno.h>
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+
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+#include "tb.h"
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+
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+
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+static void tb_dump_hop(struct tb_port *port, struct tb_regs_hop *hop)
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+{
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+ tb_port_info(port, " Hop through port %d to hop %d (%s)\n",
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+ hop->out_port, hop->next_hop,
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+ hop->enable ? "enabled" : "disabled");
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+ tb_port_info(port, " Weight: %d Priority: %d Credits: %d Drop: %d\n",
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+ hop->weight, hop->priority,
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+ hop->initial_credits, hop->drop_packages);
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+ tb_port_info(port, " Counter enabled: %d Counter index: %d\n",
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+ hop->counter_enable, hop->counter);
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+ tb_port_info(port, " Flow Control (In/Eg): %d/%d Shared Buffer (In/Eg): %d/%d\n",
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+ hop->ingress_fc, hop->egress_fc,
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+ hop->ingress_shared_buffer, hop->egress_shared_buffer);
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+ tb_port_info(port, " Unknown1: %#x Unknown2: %#x Unknown3: %#x\n",
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+ hop->unknown1, hop->unknown2, hop->unknown3);
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+}
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+
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+/**
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+ * tb_path_alloc() - allocate a thunderbolt path
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+ *
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+ * Return: Returns a tb_path on success or NULL on failure.
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+ */
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+struct tb_path *tb_path_alloc(struct tb *tb, int num_hops)
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+{
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+ struct tb_path *path = kzalloc(sizeof(*path), GFP_KERNEL);
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+ if (!path)
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+ return NULL;
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+ path->hops = kcalloc(num_hops, sizeof(*path->hops), GFP_KERNEL);
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+ if (!path->hops) {
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+ kfree(path);
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+ return NULL;
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+ }
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+ path->tb = tb;
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+ path->path_length = num_hops;
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+ return path;
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+}
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+
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+/**
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+ * tb_path_free() - free a deactivated path
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+ */
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+void tb_path_free(struct tb_path *path)
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+{
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+ if (path->activated) {
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+ tb_WARN(path->tb, "trying to free an activated path\n")
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+ return;
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+ }
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+ kfree(path->hops);
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+ kfree(path);
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+}
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+
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+static void __tb_path_deallocate_nfc(struct tb_path *path, int first_hop)
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+{
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+ int i, res;
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+ for (i = first_hop; i < path->path_length; i++) {
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+ res = tb_port_add_nfc_credits(path->hops[i].in_port,
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+ -path->nfc_credits);
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+ if (res)
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+ tb_port_warn(path->hops[i].in_port,
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+ "nfc credits deallocation failed for hop %d\n",
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+ i);
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+ }
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+}
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+
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+static void __tb_path_deactivate_hops(struct tb_path *path, int first_hop)
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+{
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+ int i, res;
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+ struct tb_regs_hop hop = { };
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+ for (i = first_hop; i < path->path_length; i++) {
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+ res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,
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+ 2 * path->hops[i].in_hop_index, 2);
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+ if (res)
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+ tb_port_warn(path->hops[i].in_port,
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+ "hop deactivation failed for hop %d, index %d\n",
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+ i, path->hops[i].in_hop_index);
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+ }
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+}
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+
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+void tb_path_deactivate(struct tb_path *path)
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+{
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+ if (!path->activated) {
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+ tb_WARN(path->tb, "trying to deactivate an inactive path\n");
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+ return;
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+ }
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+ tb_info(path->tb,
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+ "deactivating path from %llx:%x to %llx:%x\n",
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+ tb_route(path->hops[0].in_port->sw),
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+ path->hops[0].in_port->port,
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+ tb_route(path->hops[path->path_length - 1].out_port->sw),
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+ path->hops[path->path_length - 1].out_port->port);
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+ __tb_path_deactivate_hops(path, 0);
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+ __tb_path_deallocate_nfc(path, 0);
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+ path->activated = false;
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+}
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+
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+/**
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+ * tb_path_activate() - activate a path
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+ *
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+ * Activate a path starting with the last hop and iterating backwards. The
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+ * caller must fill path->hops before calling tb_path_activate().
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+ *
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+ * Return: Returns 0 on success or an error code on failure.
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+ */
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+int tb_path_activate(struct tb_path *path)
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+{
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+ int i, res;
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+ enum tb_path_port out_mask, in_mask;
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+ if (path->activated) {
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+ tb_WARN(path->tb, "trying to activate already activated path\n");
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+ return -EINVAL;
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+ }
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+
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+ tb_info(path->tb,
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+ "activating path from %llx:%x to %llx:%x\n",
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+ tb_route(path->hops[0].in_port->sw),
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+ path->hops[0].in_port->port,
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+ tb_route(path->hops[path->path_length - 1].out_port->sw),
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+ path->hops[path->path_length - 1].out_port->port);
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+
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+ /* Clear counters. */
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+ for (i = path->path_length - 1; i >= 0; i--) {
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+ if (path->hops[i].in_counter_index == -1)
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+ continue;
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+ res = tb_port_clear_counter(path->hops[i].in_port,
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+ path->hops[i].in_counter_index);
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+ if (res)
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+ goto err;
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+ }
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+
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+ /* Add non flow controlled credits. */
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+ for (i = path->path_length - 1; i >= 0; i--) {
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+ res = tb_port_add_nfc_credits(path->hops[i].in_port,
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+ path->nfc_credits);
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+ if (res) {
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+ __tb_path_deallocate_nfc(path, i);
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+ goto err;
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+ }
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+ }
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+
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+ /* Activate hops. */
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+ for (i = path->path_length - 1; i >= 0; i--) {
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+ struct tb_regs_hop hop;
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+
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+ /* dword 0 */
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+ hop.next_hop = path->hops[i].next_hop_index;
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+ hop.out_port = path->hops[i].out_port->port;
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+ /* TODO: figure out why these are good values */
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+ hop.initial_credits = (i == path->path_length - 1) ? 16 : 7;
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+ hop.unknown1 = 0;
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+ hop.enable = 1;
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+
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+ /* dword 1 */
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+ out_mask = (i == path->path_length - 1) ?
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+ TB_PATH_DESTINATION : TB_PATH_INTERNAL;
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+ in_mask = (i == 0) ? TB_PATH_SOURCE : TB_PATH_INTERNAL;
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+ hop.weight = path->weight;
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+ hop.unknown2 = 0;
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+ hop.priority = path->priority;
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+ hop.drop_packages = path->drop_packages;
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+ hop.counter = path->hops[i].in_counter_index;
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+ hop.counter_enable = path->hops[i].in_counter_index != -1;
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+ hop.ingress_fc = path->ingress_fc_enable & in_mask;
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+ hop.egress_fc = path->egress_fc_enable & out_mask;
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+ hop.ingress_shared_buffer = path->ingress_shared_buffer
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+ & in_mask;
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+ hop.egress_shared_buffer = path->egress_shared_buffer
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+ & out_mask;
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+ hop.unknown3 = 0;
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+
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+ tb_port_info(path->hops[i].in_port, "Writing hop %d, index %d",
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+ i, path->hops[i].in_hop_index);
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+ tb_dump_hop(path->hops[i].in_port, &hop);
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+ res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,
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+ 2 * path->hops[i].in_hop_index, 2);
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+ if (res) {
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+ __tb_path_deactivate_hops(path, i);
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+ __tb_path_deallocate_nfc(path, 0);
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+ goto err;
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+ }
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+ }
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+ path->activated = true;
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+ tb_info(path->tb, "path activation complete\n");
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+ return 0;
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+err:
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+ tb_WARN(path->tb, "path activation failed\n");
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+ return res;
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+}
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+
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+/**
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+ * tb_path_is_invalid() - check whether any ports on the path are invalid
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+ *
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+ * Return: Returns true if the path is invalid, false otherwise.
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+ */
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+bool tb_path_is_invalid(struct tb_path *path)
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+{
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+ int i = 0;
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+ for (i = 0; i < path->path_length; i++) {
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+ if (path->hops[i].in_port->sw->is_unplugged)
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+ return true;
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+ if (path->hops[i].out_port->sw->is_unplugged)
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+ return true;
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+ }
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+ return false;
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+}
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diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
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index d6c32e1..667413f 100644
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--- a/drivers/thunderbolt/switch.c
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+++ b/drivers/thunderbolt/switch.c
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@@ -139,6 +139,40 @@ int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
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}
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/**
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+ * tb_port_add_nfc_credits() - add/remove non flow controlled credits to port
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+ *
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+ * Change the number of NFC credits allocated to @port by @credits. To remove
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+ * NFC credits pass a negative amount of credits.
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+ *
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+ * Return: Returns 0 on success or an error code on failure.
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+ */
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+int tb_port_add_nfc_credits(struct tb_port *port, int credits)
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+{
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+ if (credits == 0)
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+ return 0;
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+ tb_port_info(port,
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+ "adding %#x NFC credits (%#x -> %#x)",
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+ credits,
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+ port->config.nfc_credits,
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+ port->config.nfc_credits + credits);
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+ port->config.nfc_credits += credits;
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+ return tb_port_write(port, &port->config.nfc_credits,
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+ TB_CFG_PORT, 4, 1);
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+}
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+
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+/**
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+ * tb_port_clear_counter() - clear a counter in TB_CFG_COUNTER
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+ *
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+ * Return: Returns 0 on success or an error code on failure.
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+ */
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+int tb_port_clear_counter(struct tb_port *port, int counter)
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+{
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+ u32 zero[3] = { 0, 0, 0 };
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+ tb_port_info(port, "clearing counter %d\n", counter);
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+ return tb_port_write(port, zero, TB_CFG_COUNTERS, 3 * counter, 3);
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+}
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+
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+/**
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* tb_init_port() - initialize a port
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*
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* This is a helper method for tb_switch_alloc. Does not check or initialize
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diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
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index 661f182..8bbdc2b 100644
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--- a/drivers/thunderbolt/tb.h
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+++ b/drivers/thunderbolt/tb.h
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@@ -35,6 +35,60 @@ struct tb_port {
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};
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/**
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+ * struct tb_path_hop - routing information for a tb_path
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+ *
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+ * Hop configuration is always done on the IN port of a switch.
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+ * in_port and out_port have to be on the same switch. Packets arriving on
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+ * in_port with "hop" = in_hop_index will get routed to through out_port. The
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+ * next hop to take (on out_port->remote) is determined by next_hop_index.
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+ *
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+ * in_counter_index is the index of a counter (in TB_CFG_COUNTERS) on the in
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+ * port.
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+ */
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+struct tb_path_hop {
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+ struct tb_port *in_port;
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+ struct tb_port *out_port;
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+ int in_hop_index;
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+ int in_counter_index; /* write -1 to disable counters for this hop. */
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+ int next_hop_index;
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+};
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+
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+/**
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+ * enum tb_path_port - path options mask
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+ */
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+enum tb_path_port {
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+ TB_PATH_NONE = 0,
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+ TB_PATH_SOURCE = 1, /* activate on the first hop (out of src) */
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+ TB_PATH_INTERNAL = 2, /* activate on other hops (not the first/last) */
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+ TB_PATH_DESTINATION = 4, /* activate on the last hop (into dst) */
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+ TB_PATH_ALL = 7,
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+};
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+
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+/**
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+ * struct tb_path - a unidirectional path between two ports
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+ *
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+ * A path consists of a number of hops (see tb_path_hop). To establish a PCIe
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+ * tunnel two paths have to be created between the two PCIe ports.
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+ *
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+ */
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+struct tb_path {
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+ struct tb *tb;
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+ int nfc_credits; /* non flow controlled credits */
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+ enum tb_path_port ingress_shared_buffer;
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+ enum tb_path_port egress_shared_buffer;
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+ enum tb_path_port ingress_fc_enable;
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+ enum tb_path_port egress_fc_enable;
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+
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+ int priority:3;
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+ int weight:4;
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+ bool drop_packages;
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+ bool activated;
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+ struct tb_path_hop *hops;
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+ int path_length; /* number of hops */
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+};
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+
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+
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+/**
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* struct tb - main thunderbolt bus structure
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*/
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struct tb {
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@@ -165,9 +219,17 @@ void tb_sw_set_unpplugged(struct tb_switch *sw);
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struct tb_switch *get_switch_at_route(struct tb_switch *sw, u64 route);
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int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged);
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+int tb_port_add_nfc_credits(struct tb_port *port, int credits);
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+int tb_port_clear_counter(struct tb_port *port, int counter);
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int tb_find_cap(struct tb_port *port, enum tb_cfg_space space, u32 value);
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+struct tb_path *tb_path_alloc(struct tb *tb, int num_hops);
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+void tb_path_free(struct tb_path *path);
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+int tb_path_activate(struct tb_path *path);
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+void tb_path_deactivate(struct tb_path *path);
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+bool tb_path_is_invalid(struct tb_path *path);
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+
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static inline int tb_route_length(u64 route)
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{
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