linux/drivers/thunderbolt/tmu.c
Gil Fine 43f977bc60 thunderbolt: Enable CL0s for Intel Titan Ridge
Low power link states (called collectively CLx) are used to reduce
transmitter and receiver power when a high-speed lane is idle. The
simplest one being called CL0s. Follow what we already do for USB4
device routers and enable CL0s for Intel Titan Ridge device router too.
This allows better thermal management.

Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2021-12-28 10:43:56 +03:00

621 lines
15 KiB
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 inline int tb_port_tmu_unidirectional_enable(struct tb_port *port)
{
return tb_port_tmu_set_unidirectional(port, true);
}
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_port_tmu_time_sync(struct tb_port *port, bool time_sync)
{
u32 val = time_sync ? TMU_ADP_CS_6_DTS : 0;
return tb_port_tmu_write(port, TMU_ADP_CS_6, TMU_ADP_CS_6_DTS, val);
}
static int tb_port_tmu_time_sync_disable(struct tb_port *port)
{
return tb_port_tmu_time_sync(port, true);
}
static int tb_port_tmu_time_sync_enable(struct tb_port *port)
{
return tb_port_tmu_time_sync(port, false);
}
static int tb_switch_tmu_set_time_disruption(struct tb_switch *sw, bool set)
{
u32 val, offset, bit;
int ret;
if (tb_switch_is_usb4(sw)) {
offset = sw->tmu.cap + TMU_RTR_CS_0;
bit = TMU_RTR_CS_0_TD;
} else {
offset = sw->cap_vsec_tmu + TB_TIME_VSEC_3_CS_26;
bit = TB_TIME_VSEC_3_CS_26_TD;
}
ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, offset, 1);
if (ret)
return ret;
if (set)
val |= bit;
else
val &= ~bit;
return tb_sw_write(sw, &val, TB_CFG_SWITCH, offset, 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_time_high_offset, post_time_high = 0;
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;
post_time_high_offset = sw->tmu.cap + TMU_RTR_CS_25;
/*
* 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:
* 1) writing 0x1 to the Post Time Low register and 0xffffffff to
* Post Time High register.
* 2) write 0 to Post Time High register and then wait for
* the completion of the post_time register becomes 0.
* This means the time has been converged properly.
*/
post_time = 0xffffffff00000001ULL;
ret = tb_sw_write(sw, &post_time, TB_CFG_SWITCH, post_time_offset, 2);
if (ret)
goto out;
ret = tb_sw_write(sw, &post_time_high, TB_CFG_SWITCH,
post_time_high_offset, 1);
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)
{
/*
* No need to disable TMU on devices that don't support CLx since
* on these devices e.g. Alpine Ridge and earlier, the TMU mode
* HiFi bi-directional is enabled by default and we don't change it.
*/
if (!tb_switch_is_clx_supported(sw))
return 0;
/* Already disabled? */
if (sw->tmu.rate == TB_SWITCH_TMU_RATE_OFF)
return 0;
if (tb_route(sw)) {
bool unidirectional = tb_switch_tmu_hifi_is_enabled(sw, true);
struct tb_switch *parent = tb_switch_parent(sw);
struct tb_port *down, *up;
int ret;
down = tb_port_at(tb_route(sw), parent);
up = tb_upstream_port(sw);
/*
* In case of uni-directional time sync, TMU handshake is
* initiated by upstream router. In case of bi-directional
* time sync, TMU handshake is initiated by downstream router.
* Therefore, we change the rate to off in the respective
* router.
*/
if (unidirectional)
tb_switch_tmu_rate_write(parent, TB_SWITCH_TMU_RATE_OFF);
else
tb_switch_tmu_rate_write(sw, TB_SWITCH_TMU_RATE_OFF);
tb_port_tmu_time_sync_disable(up);
ret = tb_port_tmu_time_sync_disable(down);
if (ret)
return ret;
if (unidirectional) {
/* 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;
}
} else {
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;
}
static void __tb_switch_tmu_off(struct tb_switch *sw, bool unidirectional)
{
struct tb_switch *parent = tb_switch_parent(sw);
struct tb_port *down, *up;
down = tb_port_at(tb_route(sw), parent);
up = tb_upstream_port(sw);
/*
* In case of any failure in one of the steps when setting
* bi-directional or uni-directional TMU mode, get back to the TMU
* configurations in off mode. In case of additional failures in
* the functions below, ignore them since the caller shall already
* report a failure.
*/
tb_port_tmu_time_sync_disable(down);
tb_port_tmu_time_sync_disable(up);
if (unidirectional)
tb_switch_tmu_rate_write(parent, TB_SWITCH_TMU_RATE_OFF);
else
tb_switch_tmu_rate_write(sw, TB_SWITCH_TMU_RATE_OFF);
tb_port_tmu_unidirectional_disable(down);
tb_port_tmu_unidirectional_disable(up);
}
/*
* This function is called when the previous TMU mode was
* TB_SWITCH_TMU_RATE_OFF.
*/
static int __tb_switch_tmu_enable_bidirectional(struct tb_switch *sw)
{
struct tb_switch *parent = tb_switch_parent(sw);
struct tb_port *up, *down;
int ret;
up = tb_upstream_port(sw);
down = tb_port_at(tb_route(sw), parent);
ret = tb_port_tmu_unidirectional_disable(up);
if (ret)
return ret;
ret = tb_port_tmu_unidirectional_disable(down);
if (ret)
goto out;
ret = tb_switch_tmu_rate_write(sw, TB_SWITCH_TMU_RATE_HIFI);
if (ret)
goto out;
ret = tb_port_tmu_time_sync_enable(up);
if (ret)
goto out;
ret = tb_port_tmu_time_sync_enable(down);
if (ret)
goto out;
return 0;
out:
__tb_switch_tmu_off(sw, false);
return ret;
}
static int tb_switch_tmu_objection_mask(struct tb_switch *sw)
{
u32 val;
int ret;
ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
sw->cap_vsec_tmu + TB_TIME_VSEC_3_CS_9, 1);
if (ret)
return ret;
val &= ~TB_TIME_VSEC_3_CS_9_TMU_OBJ_MASK;
return tb_sw_write(sw, &val, TB_CFG_SWITCH,
sw->cap_vsec_tmu + TB_TIME_VSEC_3_CS_9, 1);
}
static int tb_switch_tmu_unidirectional_enable(struct tb_switch *sw)
{
struct tb_port *up = tb_upstream_port(sw);
return tb_port_tmu_write(up, TMU_ADP_CS_6,
TMU_ADP_CS_6_DISABLE_TMU_OBJ_MASK,
TMU_ADP_CS_6_DISABLE_TMU_OBJ_MASK);
}
/*
* This function is called when the previous TMU mode was
* TB_SWITCH_TMU_RATE_OFF.
*/
static int __tb_switch_tmu_enable_unidirectional(struct tb_switch *sw)
{
struct tb_switch *parent = tb_switch_parent(sw);
struct tb_port *up, *down;
int ret;
up = tb_upstream_port(sw);
down = tb_port_at(tb_route(sw), parent);
ret = tb_switch_tmu_rate_write(parent, TB_SWITCH_TMU_RATE_HIFI);
if (ret)
return ret;
ret = tb_port_tmu_unidirectional_enable(up);
if (ret)
goto out;
ret = tb_port_tmu_time_sync_enable(up);
if (ret)
goto out;
ret = tb_port_tmu_unidirectional_enable(down);
if (ret)
goto out;
ret = tb_port_tmu_time_sync_enable(down);
if (ret)
goto out;
return 0;
out:
__tb_switch_tmu_off(sw, true);
return ret;
}
static int tb_switch_tmu_hifi_enable(struct tb_switch *sw)
{
bool unidirectional = sw->tmu.unidirectional_request;
int ret;
if (unidirectional && !sw->tmu.has_ucap)
return -EOPNOTSUPP;
/*
* No need to enable TMU on devices that don't support CLx since on
* these devices e.g. Alpine Ridge and earlier, the TMU mode HiFi
* bi-directional is enabled by default.
*/
if (!tb_switch_is_clx_supported(sw))
return 0;
if (tb_switch_tmu_hifi_is_enabled(sw, sw->tmu.unidirectional_request))
return 0;
if (tb_switch_is_titan_ridge(sw) && unidirectional) {
/* Titan Ridge supports only CL0s */
if (!tb_switch_is_cl0s_enabled(sw))
return -EOPNOTSUPP;
ret = tb_switch_tmu_objection_mask(sw);
if (ret)
return ret;
ret = tb_switch_tmu_unidirectional_enable(sw);
if (ret)
return ret;
}
ret = tb_switch_tmu_set_time_disruption(sw, true);
if (ret)
return ret;
if (tb_route(sw)) {
/* The used mode changes are from OFF to HiFi-Uni/HiFi-BiDir */
if (sw->tmu.rate == TB_SWITCH_TMU_RATE_OFF) {
if (unidirectional)
ret = __tb_switch_tmu_enable_unidirectional(sw);
else
ret = __tb_switch_tmu_enable_bidirectional(sw);
if (ret)
return ret;
}
sw->tmu.unidirectional = unidirectional;
} else {
/*
* Host router port configurations are written as
* part of configurations for downstream port of the parent
* of the child node - see above.
* Here only the host router' rate configuration is written.
*/
ret = tb_switch_tmu_rate_write(sw, TB_SWITCH_TMU_RATE_HIFI);
if (ret)
return ret;
}
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);
}
/**
* tb_switch_tmu_enable() - Enable TMU on a router
* @sw: Router whose TMU to enable
*
* Enables TMU of a router to be in uni-directional or bi-directional HiFi mode.
* Calling tb_switch_tmu_configure() is required before calling this function,
* to select the mode HiFi and directionality (uni-directional/bi-directional).
* In both modes all tunneling should work. Uni-directional mode is required for
* CLx (Link Low-Power) to work.
*/
int tb_switch_tmu_enable(struct tb_switch *sw)
{
if (sw->tmu.rate_request == TB_SWITCH_TMU_RATE_NORMAL)
return -EOPNOTSUPP;
return tb_switch_tmu_hifi_enable(sw);
}
/**
* tb_switch_tmu_configure() - Configure the TMU rate and directionality
* @sw: Router whose mode to change
* @rate: Rate to configure Off/LowRes/HiFi
* @unidirectional: If uni-directional (bi-directional otherwise)
*
* Selects the rate of the TMU and directionality (uni-directional or
* bi-directional). Must be called before tb_switch_tmu_enable().
*/
void tb_switch_tmu_configure(struct tb_switch *sw,
enum tb_switch_tmu_rate rate, bool unidirectional)
{
sw->tmu.unidirectional_request = unidirectional;
sw->tmu.rate_request = rate;
}