https://github.com/torvalds/linux
Tip revision: 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 authored by Linus Torvalds on 31 May 2020, 23:49:15 UTC
Linux 5.7
Linux 5.7
Tip revision: 3d77e6a
tmu.c
// SPDX-License-Identifier: GPL-2.0
/*
* Thunderbolt Time Management Unit (TMU) support
*
* Copyright (C) 2019, Intel Corporation
* Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
* Rajmohan Mani <rajmohan.mani@intel.com>
*/
#include <linux/delay.h>
#include "tb.h"
static const char *tb_switch_tmu_mode_name(const struct tb_switch *sw)
{
bool root_switch = !tb_route(sw);
switch (sw->tmu.rate) {
case TB_SWITCH_TMU_RATE_OFF:
return "off";
case TB_SWITCH_TMU_RATE_HIFI:
/* Root switch does not have upstream directionality */
if (root_switch)
return "HiFi";
if (sw->tmu.unidirectional)
return "uni-directional, HiFi";
return "bi-directional, HiFi";
case TB_SWITCH_TMU_RATE_NORMAL:
if (root_switch)
return "normal";
return "uni-directional, normal";
default:
return "unknown";
}
}
static bool tb_switch_tmu_ucap_supported(struct tb_switch *sw)
{
int ret;
u32 val;
ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
sw->tmu.cap + TMU_RTR_CS_0, 1);
if (ret)
return false;
return !!(val & TMU_RTR_CS_0_UCAP);
}
static int tb_switch_tmu_rate_read(struct tb_switch *sw)
{
int ret;
u32 val;
ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
sw->tmu.cap + TMU_RTR_CS_3, 1);
if (ret)
return ret;
val >>= TMU_RTR_CS_3_TS_PACKET_INTERVAL_SHIFT;
return val;
}
static int tb_switch_tmu_rate_write(struct tb_switch *sw, int rate)
{
int ret;
u32 val;
ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
sw->tmu.cap + TMU_RTR_CS_3, 1);
if (ret)
return ret;
val &= ~TMU_RTR_CS_3_TS_PACKET_INTERVAL_MASK;
val |= rate << TMU_RTR_CS_3_TS_PACKET_INTERVAL_SHIFT;
return tb_sw_write(sw, &val, TB_CFG_SWITCH,
sw->tmu.cap + TMU_RTR_CS_3, 1);
}
static int tb_port_tmu_write(struct tb_port *port, u8 offset, u32 mask,
u32 value)
{
u32 data;
int ret;
ret = tb_port_read(port, &data, TB_CFG_PORT, port->cap_tmu + offset, 1);
if (ret)
return ret;
data &= ~mask;
data |= value;
return tb_port_write(port, &data, TB_CFG_PORT,
port->cap_tmu + offset, 1);
}
static int tb_port_tmu_set_unidirectional(struct tb_port *port,
bool unidirectional)
{
u32 val;
if (!port->sw->tmu.has_ucap)
return 0;
val = unidirectional ? TMU_ADP_CS_3_UDM : 0;
return tb_port_tmu_write(port, TMU_ADP_CS_3, TMU_ADP_CS_3_UDM, val);
}
static inline int tb_port_tmu_unidirectional_disable(struct tb_port *port)
{
return tb_port_tmu_set_unidirectional(port, false);
}
static bool tb_port_tmu_is_unidirectional(struct tb_port *port)
{
int ret;
u32 val;
ret = tb_port_read(port, &val, TB_CFG_PORT,
port->cap_tmu + TMU_ADP_CS_3, 1);
if (ret)
return false;
return val & TMU_ADP_CS_3_UDM;
}
static int tb_switch_tmu_set_time_disruption(struct tb_switch *sw, bool set)
{
int ret;
u32 val;
ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
sw->tmu.cap + TMU_RTR_CS_0, 1);
if (ret)
return ret;
if (set)
val |= TMU_RTR_CS_0_TD;
else
val &= ~TMU_RTR_CS_0_TD;
return tb_sw_write(sw, &val, TB_CFG_SWITCH,
sw->tmu.cap + TMU_RTR_CS_0, 1);
}
/**
* tb_switch_tmu_init() - Initialize switch TMU structures
* @sw: Switch to initialized
*
* This function must be called before other TMU related functions to
* makes the internal structures are filled in correctly. Does not
* change any hardware configuration.
*/
int tb_switch_tmu_init(struct tb_switch *sw)
{
struct tb_port *port;
int ret;
if (tb_switch_is_icm(sw))
return 0;
ret = tb_switch_find_cap(sw, TB_SWITCH_CAP_TMU);
if (ret > 0)
sw->tmu.cap = ret;
tb_switch_for_each_port(sw, port) {
int cap;
cap = tb_port_find_cap(port, TB_PORT_CAP_TIME1);
if (cap > 0)
port->cap_tmu = cap;
}
ret = tb_switch_tmu_rate_read(sw);
if (ret < 0)
return ret;
sw->tmu.rate = ret;
sw->tmu.has_ucap = tb_switch_tmu_ucap_supported(sw);
if (sw->tmu.has_ucap) {
tb_sw_dbg(sw, "TMU: supports uni-directional mode\n");
if (tb_route(sw)) {
struct tb_port *up = tb_upstream_port(sw);
sw->tmu.unidirectional =
tb_port_tmu_is_unidirectional(up);
}
} else {
sw->tmu.unidirectional = false;
}
tb_sw_dbg(sw, "TMU: current mode: %s\n", tb_switch_tmu_mode_name(sw));
return 0;
}
/**
* tb_switch_tmu_post_time() - Update switch local time
* @sw: Switch whose time to update
*
* Updates switch local time using time posting procedure.
*/
int tb_switch_tmu_post_time(struct tb_switch *sw)
{
unsigned int post_local_time_offset, post_time_offset;
struct tb_switch *root_switch = sw->tb->root_switch;
u64 hi, mid, lo, local_time, post_time;
int i, ret, retries = 100;
u32 gm_local_time[3];
if (!tb_route(sw))
return 0;
if (!tb_switch_is_usb4(sw))
return 0;
/* Need to be able to read the grand master time */
if (!root_switch->tmu.cap)
return 0;
ret = tb_sw_read(root_switch, gm_local_time, TB_CFG_SWITCH,
root_switch->tmu.cap + TMU_RTR_CS_1,
ARRAY_SIZE(gm_local_time));
if (ret)
return ret;
for (i = 0; i < ARRAY_SIZE(gm_local_time); i++)
tb_sw_dbg(root_switch, "local_time[%d]=0x%08x\n", i,
gm_local_time[i]);
/* Convert to nanoseconds (drop fractional part) */
hi = gm_local_time[2] & TMU_RTR_CS_3_LOCAL_TIME_NS_MASK;
mid = gm_local_time[1];
lo = (gm_local_time[0] & TMU_RTR_CS_1_LOCAL_TIME_NS_MASK) >>
TMU_RTR_CS_1_LOCAL_TIME_NS_SHIFT;
local_time = hi << 48 | mid << 16 | lo;
/* Tell the switch that time sync is disrupted for a while */
ret = tb_switch_tmu_set_time_disruption(sw, true);
if (ret)
return ret;
post_local_time_offset = sw->tmu.cap + TMU_RTR_CS_22;
post_time_offset = sw->tmu.cap + TMU_RTR_CS_24;
/*
* Write the Grandmaster time to the Post Local Time registers
* of the new switch.
*/
ret = tb_sw_write(sw, &local_time, TB_CFG_SWITCH,
post_local_time_offset, 2);
if (ret)
goto out;
/*
* Have the new switch update its local time (by writing 1 to
* the post_time registers) and wait for the completion of the
* same (post_time register becomes 0). This means the time has
* been converged properly.
*/
post_time = 1;
ret = tb_sw_write(sw, &post_time, TB_CFG_SWITCH, post_time_offset, 2);
if (ret)
goto out;
do {
usleep_range(5, 10);
ret = tb_sw_read(sw, &post_time, TB_CFG_SWITCH,
post_time_offset, 2);
if (ret)
goto out;
} while (--retries && post_time);
if (!retries) {
ret = -ETIMEDOUT;
goto out;
}
tb_sw_dbg(sw, "TMU: updated local time to %#llx\n", local_time);
out:
tb_switch_tmu_set_time_disruption(sw, false);
return ret;
}
/**
* tb_switch_tmu_disable() - Disable TMU of a switch
* @sw: Switch whose TMU to disable
*
* Turns off TMU of @sw if it is enabled. If not enabled does nothing.
*/
int tb_switch_tmu_disable(struct tb_switch *sw)
{
int ret;
if (!tb_switch_is_usb4(sw))
return 0;
/* Already disabled? */
if (sw->tmu.rate == TB_SWITCH_TMU_RATE_OFF)
return 0;
if (sw->tmu.unidirectional) {
struct tb_switch *parent = tb_switch_parent(sw);
struct tb_port *up, *down;
up = tb_upstream_port(sw);
down = tb_port_at(tb_route(sw), parent);
/* The switch may be unplugged so ignore any errors */
tb_port_tmu_unidirectional_disable(up);
ret = tb_port_tmu_unidirectional_disable(down);
if (ret)
return ret;
}
tb_switch_tmu_rate_write(sw, TB_SWITCH_TMU_RATE_OFF);
sw->tmu.unidirectional = false;
sw->tmu.rate = TB_SWITCH_TMU_RATE_OFF;
tb_sw_dbg(sw, "TMU: disabled\n");
return 0;
}
/**
* tb_switch_tmu_enable() - Enable TMU on a switch
* @sw: Switch whose TMU to enable
*
* Enables TMU of a switch to be in bi-directional, HiFi mode. In this mode
* all tunneling should work.
*/
int tb_switch_tmu_enable(struct tb_switch *sw)
{
int ret;
if (!tb_switch_is_usb4(sw))
return 0;
if (tb_switch_tmu_is_enabled(sw))
return 0;
ret = tb_switch_tmu_set_time_disruption(sw, true);
if (ret)
return ret;
/* Change mode to bi-directional */
if (tb_route(sw) && sw->tmu.unidirectional) {
struct tb_switch *parent = tb_switch_parent(sw);
struct tb_port *up, *down;
up = tb_upstream_port(sw);
down = tb_port_at(tb_route(sw), parent);
ret = tb_port_tmu_unidirectional_disable(down);
if (ret)
return ret;
ret = tb_switch_tmu_rate_write(sw, TB_SWITCH_TMU_RATE_HIFI);
if (ret)
return ret;
ret = tb_port_tmu_unidirectional_disable(up);
if (ret)
return ret;
} else {
ret = tb_switch_tmu_rate_write(sw, TB_SWITCH_TMU_RATE_HIFI);
if (ret)
return ret;
}
sw->tmu.unidirectional = false;
sw->tmu.rate = TB_SWITCH_TMU_RATE_HIFI;
tb_sw_dbg(sw, "TMU: mode set to: %s\n", tb_switch_tmu_mode_name(sw));
return tb_switch_tmu_set_time_disruption(sw, false);
}