linux/drivers/thunderbolt/path.c

592 lines
15 KiB
C
Raw Normal View History

License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 14:07:57 +00:00
// SPDX-License-Identifier: GPL-2.0
/*
* Thunderbolt driver - path/tunnel functionality
*
* Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
* Copyright (C) 2019, Intel Corporation
*/
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/ktime.h>
#include "tb.h"
static void tb_dump_hop(const struct tb_path_hop *hop, const struct tb_regs_hop *regs)
{
const struct tb_port *port = hop->in_port;
tb_port_dbg(port, " In HopID: %d => Out port: %d Out HopID: %d\n",
hop->in_hop_index, regs->out_port, regs->next_hop);
tb_port_dbg(port, " Weight: %d Priority: %d Credits: %d Drop: %d\n",
regs->weight, regs->priority,
regs->initial_credits, regs->drop_packages);
tb_port_dbg(port, " Counter enabled: %d Counter index: %d\n",
regs->counter_enable, regs->counter);
tb_port_dbg(port, " Flow Control (In/Eg): %d/%d Shared Buffer (In/Eg): %d/%d\n",
regs->ingress_fc, regs->egress_fc,
regs->ingress_shared_buffer, regs->egress_shared_buffer);
tb_port_dbg(port, " Unknown1: %#x Unknown2: %#x Unknown3: %#x\n",
regs->unknown1, regs->unknown2, regs->unknown3);
}
static struct tb_port *tb_path_find_dst_port(struct tb_port *src, int src_hopid,
int dst_hopid)
{
struct tb_port *port, *out_port = NULL;
struct tb_regs_hop hop;
struct tb_switch *sw;
int i, ret, hopid;
hopid = src_hopid;
port = src;
for (i = 0; port && i < TB_PATH_MAX_HOPS; i++) {
sw = port->sw;
ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hopid, 2);
if (ret) {
tb_port_warn(port, "failed to read path at %d\n", hopid);
return NULL;
}
if (!hop.enable)
return NULL;
out_port = &sw->ports[hop.out_port];
hopid = hop.next_hop;
port = out_port->remote;
}
return out_port && hopid == dst_hopid ? out_port : NULL;
}
static int tb_path_find_src_hopid(struct tb_port *src,
const struct tb_port *dst, int dst_hopid)
{
struct tb_port *out;
int i;
for (i = TB_PATH_MIN_HOPID; i <= src->config.max_in_hop_id; i++) {
out = tb_path_find_dst_port(src, i, dst_hopid);
if (out == dst)
return i;
}
return 0;
}
/**
* tb_path_discover() - Discover a path
* @src: First input port of a path
* @src_hopid: Starting HopID of a path (%-1 if don't care)
* @dst: Expected destination port of the path (%NULL if don't care)
* @dst_hopid: HopID to the @dst (%-1 if don't care)
* @last: Last port is filled here if not %NULL
* @name: Name of the path
*
* Follows a path starting from @src and @src_hopid to the last output
* port of the path. Allocates HopIDs for the visited ports. Call
* tb_path_free() to release the path and allocated HopIDs when the path
* is not needed anymore.
*
* Note function discovers also incomplete paths so caller should check
* that the @dst port is the expected one. If it is not, the path can be
* cleaned up by calling tb_path_deactivate() before tb_path_free().
*
* Return: Discovered path on success, %NULL in case of failure
*/
struct tb_path *tb_path_discover(struct tb_port *src, int src_hopid,
struct tb_port *dst, int dst_hopid,
struct tb_port **last, const char *name)
{
struct tb_port *out_port;
struct tb_regs_hop hop;
struct tb_path *path;
struct tb_switch *sw;
struct tb_port *p;
size_t num_hops;
int ret, i, h;
if (src_hopid < 0 && dst) {
/*
* For incomplete paths the intermediate HopID can be
* different from the one used by the protocol adapter
* so in that case find a path that ends on @dst with
* matching @dst_hopid. That should give us the correct
* HopID for the @src.
*/
src_hopid = tb_path_find_src_hopid(src, dst, dst_hopid);
if (!src_hopid)
return NULL;
}
p = src;
h = src_hopid;
num_hops = 0;
for (i = 0; p && i < TB_PATH_MAX_HOPS; i++) {
sw = p->sw;
ret = tb_port_read(p, &hop, TB_CFG_HOPS, 2 * h, 2);
if (ret) {
tb_port_warn(p, "failed to read path at %d\n", h);
return NULL;
}
/* If the hop is not enabled we got an incomplete path */
if (!hop.enable)
break;
out_port = &sw->ports[hop.out_port];
if (last)
*last = out_port;
h = hop.next_hop;
p = out_port->remote;
num_hops++;
}
path = kzalloc(sizeof(*path), GFP_KERNEL);
if (!path)
return NULL;
path->name = name;
path->tb = src->sw->tb;
path->path_length = num_hops;
path->activated = true;
path->hops = kcalloc(num_hops, sizeof(*path->hops), GFP_KERNEL);
if (!path->hops) {
kfree(path);
return NULL;
}
p = src;
h = src_hopid;
for (i = 0; i < num_hops; i++) {
int next_hop;
sw = p->sw;
ret = tb_port_read(p, &hop, TB_CFG_HOPS, 2 * h, 2);
if (ret) {
tb_port_warn(p, "failed to read path at %d\n", h);
goto err;
}
if (tb_port_alloc_in_hopid(p, h, h) < 0)
goto err;
out_port = &sw->ports[hop.out_port];
next_hop = hop.next_hop;
if (tb_port_alloc_out_hopid(out_port, next_hop, next_hop) < 0) {
tb_port_release_in_hopid(p, h);
goto err;
}
path->hops[i].in_port = p;
path->hops[i].in_hop_index = h;
path->hops[i].in_counter_index = -1;
path->hops[i].out_port = out_port;
path->hops[i].next_hop_index = next_hop;
h = next_hop;
p = out_port->remote;
}
return path;
err:
tb_port_warn(src, "failed to discover path starting at HopID %d\n",
src_hopid);
tb_path_free(path);
return NULL;
}
/**
* tb_path_alloc() - allocate a thunderbolt path between two ports
* @tb: Domain pointer
* @src: Source port of the path
* @src_hopid: HopID used for the first ingress port in the path
* @dst: Destination port of the path
* @dst_hopid: HopID used for the last egress port in the path
* @link_nr: Preferred link if there are dual links on the path
* @name: Name of the path
*
* Creates path between two ports starting with given @src_hopid. Reserves
* HopIDs for each port (they can be different from @src_hopid depending on
* how many HopIDs each port already have reserved). If there are dual
* links on the path, prioritizes using @link_nr but takes into account
* that the lanes may be bonded.
*
* Return: Returns a tb_path on success or NULL on failure.
*/
struct tb_path *tb_path_alloc(struct tb *tb, struct tb_port *src, int src_hopid,
struct tb_port *dst, int dst_hopid, int link_nr,
const char *name)
{
struct tb_port *in_port, *out_port, *first_port, *last_port;
int in_hopid, out_hopid;
struct tb_path *path;
size_t num_hops;
int i, ret;
path = kzalloc(sizeof(*path), GFP_KERNEL);
if (!path)
return NULL;
first_port = last_port = NULL;
i = 0;
tb_for_each_port_on_path(src, dst, in_port) {
if (!first_port)
first_port = in_port;
last_port = in_port;
i++;
}
/* Check that src and dst are reachable */
if (first_port != src || last_port != dst) {
kfree(path);
return NULL;
}
/* Each hop takes two ports */
num_hops = i / 2;
path->hops = kcalloc(num_hops, sizeof(*path->hops), GFP_KERNEL);
if (!path->hops) {
kfree(path);
return NULL;
}
in_hopid = src_hopid;
out_port = NULL;
for (i = 0; i < num_hops; i++) {
in_port = tb_next_port_on_path(src, dst, out_port);
if (!in_port)
goto err;
/* When lanes are bonded primary link must be used */
if (!in_port->bonded && in_port->dual_link_port &&
in_port->link_nr != link_nr)
in_port = in_port->dual_link_port;
ret = tb_port_alloc_in_hopid(in_port, in_hopid, in_hopid);
if (ret < 0)
goto err;
in_hopid = ret;
out_port = tb_next_port_on_path(src, dst, in_port);
if (!out_port)
goto err;
/*
* Pick up right port when going from non-bonded to
* bonded or from bonded to non-bonded.
*/
if (out_port->dual_link_port) {
if (!in_port->bonded && out_port->bonded &&
out_port->link_nr) {
/*
* Use primary link when going from
* non-bonded to bonded.
*/
out_port = out_port->dual_link_port;
} else if (!out_port->bonded &&
out_port->link_nr != link_nr) {
/*
* If out port is not bonded follow
* link_nr.
*/
out_port = out_port->dual_link_port;
}
}
if (i == num_hops - 1)
ret = tb_port_alloc_out_hopid(out_port, dst_hopid,
dst_hopid);
else
ret = tb_port_alloc_out_hopid(out_port, -1, -1);
if (ret < 0)
goto err;
out_hopid = ret;
path->hops[i].in_hop_index = in_hopid;
path->hops[i].in_port = in_port;
path->hops[i].in_counter_index = -1;
path->hops[i].out_port = out_port;
path->hops[i].next_hop_index = out_hopid;
in_hopid = out_hopid;
}
path->tb = tb;
path->path_length = num_hops;
path->name = name;
return path;
err:
tb_path_free(path);
return NULL;
}
/**
* tb_path_free() - free a path
* @path: Path to free
*
* Frees a path. The path does not need to be deactivated.
*/
void tb_path_free(struct tb_path *path)
{
int i;
for (i = 0; i < path->path_length; i++) {
const struct tb_path_hop *hop = &path->hops[i];
if (hop->in_port)
tb_port_release_in_hopid(hop->in_port,
hop->in_hop_index);
if (hop->out_port)
tb_port_release_out_hopid(hop->out_port,
hop->next_hop_index);
}
kfree(path->hops);
kfree(path);
}
static void __tb_path_deallocate_nfc(struct tb_path *path, int first_hop)
{
int i, res;
for (i = first_hop; i < path->path_length; i++) {
res = tb_port_add_nfc_credits(path->hops[i].in_port,
-path->nfc_credits);
if (res)
tb_port_warn(path->hops[i].in_port,
"nfc credits deallocation failed for hop %d\n",
i);
}
}
static int __tb_path_deactivate_hop(struct tb_port *port, int hop_index,
bool clear_fc)
{
struct tb_regs_hop hop;
ktime_t timeout;
int ret;
/* Disable the path */
ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
if (ret)
return ret;
/* Already disabled */
if (!hop.enable)
return 0;
hop.enable = 0;
ret = tb_port_write(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
if (ret)
return ret;
/* Wait until it is drained */
timeout = ktime_add_ms(ktime_get(), 500);
do {
ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
if (ret)
return ret;
if (!hop.pending) {
if (clear_fc) {
/* Clear flow control */
hop.ingress_fc = 0;
hop.egress_fc = 0;
hop.ingress_shared_buffer = 0;
hop.egress_shared_buffer = 0;
return tb_port_write(port, &hop, TB_CFG_HOPS,
2 * hop_index, 2);
}
return 0;
}
usleep_range(10, 20);
} while (ktime_before(ktime_get(), timeout));
return -ETIMEDOUT;
}
static void __tb_path_deactivate_hops(struct tb_path *path, int first_hop)
{
int i, res;
for (i = first_hop; i < path->path_length; i++) {
res = __tb_path_deactivate_hop(path->hops[i].in_port,
path->hops[i].in_hop_index,
path->clear_fc);
if (res && res != -ENODEV)
tb_port_warn(path->hops[i].in_port,
"hop deactivation failed for hop %d, index %d\n",
i, path->hops[i].in_hop_index);
}
}
void tb_path_deactivate(struct tb_path *path)
{
if (!path->activated) {
tb_WARN(path->tb, "trying to deactivate an inactive path\n");
return;
}
tb_dbg(path->tb,
"deactivating %s path from %llx:%x to %llx:%x\n",
path->name, tb_route(path->hops[0].in_port->sw),
path->hops[0].in_port->port,
tb_route(path->hops[path->path_length - 1].out_port->sw),
path->hops[path->path_length - 1].out_port->port);
__tb_path_deactivate_hops(path, 0);
__tb_path_deallocate_nfc(path, 0);
path->activated = false;
}
/**
* tb_path_activate() - activate a path
*
* Activate a path starting with the last hop and iterating backwards. The
* caller must fill path->hops before calling tb_path_activate().
*
* Return: Returns 0 on success or an error code on failure.
*/
int tb_path_activate(struct tb_path *path)
{
int i, res;
enum tb_path_port out_mask, in_mask;
if (path->activated) {
tb_WARN(path->tb, "trying to activate already activated path\n");
return -EINVAL;
}
tb_dbg(path->tb,
"activating %s path from %llx:%x to %llx:%x\n",
path->name, tb_route(path->hops[0].in_port->sw),
path->hops[0].in_port->port,
tb_route(path->hops[path->path_length - 1].out_port->sw),
path->hops[path->path_length - 1].out_port->port);
/* Clear counters. */
for (i = path->path_length - 1; i >= 0; i--) {
if (path->hops[i].in_counter_index == -1)
continue;
res = tb_port_clear_counter(path->hops[i].in_port,
path->hops[i].in_counter_index);
if (res)
goto err;
}
/* Add non flow controlled credits. */
for (i = path->path_length - 1; i >= 0; i--) {
res = tb_port_add_nfc_credits(path->hops[i].in_port,
path->nfc_credits);
if (res) {
__tb_path_deallocate_nfc(path, i);
goto err;
}
}
/* Activate hops. */
for (i = path->path_length - 1; i >= 0; i--) {
struct tb_regs_hop hop = { 0 };
/* If it is left active deactivate it first */
__tb_path_deactivate_hop(path->hops[i].in_port,
path->hops[i].in_hop_index, path->clear_fc);
/* dword 0 */
hop.next_hop = path->hops[i].next_hop_index;
hop.out_port = path->hops[i].out_port->port;
hop.initial_credits = path->hops[i].initial_credits;
hop.unknown1 = 0;
hop.enable = 1;
/* dword 1 */
out_mask = (i == path->path_length - 1) ?
TB_PATH_DESTINATION : TB_PATH_INTERNAL;
in_mask = (i == 0) ? TB_PATH_SOURCE : TB_PATH_INTERNAL;
hop.weight = path->weight;
hop.unknown2 = 0;
hop.priority = path->priority;
hop.drop_packages = path->drop_packages;
hop.counter = path->hops[i].in_counter_index;
hop.counter_enable = path->hops[i].in_counter_index != -1;
hop.ingress_fc = path->ingress_fc_enable & in_mask;
hop.egress_fc = path->egress_fc_enable & out_mask;
hop.ingress_shared_buffer = path->ingress_shared_buffer
& in_mask;
hop.egress_shared_buffer = path->egress_shared_buffer
& out_mask;
hop.unknown3 = 0;
tb_port_dbg(path->hops[i].in_port, "Writing hop %d\n", i);
tb_dump_hop(&path->hops[i], &hop);
res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,
2 * path->hops[i].in_hop_index, 2);
if (res) {
__tb_path_deactivate_hops(path, i);
__tb_path_deallocate_nfc(path, 0);
goto err;
}
}
path->activated = true;
tb_dbg(path->tb, "path activation complete\n");
return 0;
err:
tb_WARN(path->tb, "path activation failed\n");
return res;
}
/**
* tb_path_is_invalid() - check whether any ports on the path are invalid
*
* Return: Returns true if the path is invalid, false otherwise.
*/
bool tb_path_is_invalid(struct tb_path *path)
{
int i = 0;
for (i = 0; i < path->path_length; i++) {
if (path->hops[i].in_port->sw->is_unplugged)
return true;
if (path->hops[i].out_port->sw->is_unplugged)
return true;
}
return false;
}
/**
* tb_path_port_on_path() - Does the path go through certain port
* @path: Path to check
* @port: Switch to check
*
* Goes over all hops on path and checks if @port is any of them.
* Direction does not matter.
*/
bool tb_path_port_on_path(const struct tb_path *path, const struct tb_port *port)
{
int i;
for (i = 0; i < path->path_length; i++) {
if (path->hops[i].in_port == port ||
path->hops[i].out_port == port)
return true;
}
return false;
}