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Subject[PATCH 2/2] thunderbolt: Add support for authenticate on disconnect
Date
Some external devices can support completing thunderbolt authentication
when they are unplugged. For this to work though, the link controller must
remain operational.

The only device known to support this right now is the Dell WD19TB, so add
a quirk for this.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
---
.../ABI/testing/sysfs-bus-thunderbolt | 13 ++++++
drivers/thunderbolt/Makefile | 1 +
drivers/thunderbolt/eeprom.c | 2 +
drivers/thunderbolt/lc.c | 14 +++++++
drivers/thunderbolt/quirks.c | 38 +++++++++++++++++
drivers/thunderbolt/switch.c | 42 +++++++++++++++++--
drivers/thunderbolt/tb-quirks.h | 16 +++++++
drivers/thunderbolt/tb.h | 3 ++
drivers/thunderbolt/tb_regs.h | 1 +
9 files changed, 126 insertions(+), 4 deletions(-)
create mode 100644 drivers/thunderbolt/quirks.c
create mode 100644 drivers/thunderbolt/tb-quirks.h

diff --git a/Documentation/ABI/testing/sysfs-bus-thunderbolt b/Documentation/ABI/testing/sysfs-bus-thunderbolt
index 26b15cbc9881..30798f9a8f59 100644
--- a/Documentation/ABI/testing/sysfs-bus-thunderbolt
+++ b/Documentation/ABI/testing/sysfs-bus-thunderbolt
@@ -243,3 +243,16 @@ KernelVersion: 4.15
Contact: thunderbolt-software@lists.01.org
Description: This contains XDomain service specific settings as
bitmask. Format: %x
+
+What: /sys/bus/thunderbolt/devices/.../nvm_authenticate_on_disconnect
+Date: August 2020
+KernelVersion: 5.9
+Contact: thunderbolt-software@lists.01.org
+Description: For supported devices, automatically authenticate the new Thunderbolt
+ image when the device is disconnected from the host system.
+
+ This file will accept writing values "1" or "2"
+ - Writing "1" will flush the image to the storage
+ area and prepare the device for authentication on disconnect.
+ - Writing "2" will only flush the image to the storage
+ area.
diff --git a/drivers/thunderbolt/Makefile b/drivers/thunderbolt/Makefile
index eae28dd45250..013c5564565a 100644
--- a/drivers/thunderbolt/Makefile
+++ b/drivers/thunderbolt/Makefile
@@ -2,3 +2,4 @@
obj-${CONFIG_USB4} := thunderbolt.o
thunderbolt-objs := nhi.o nhi_ops.o ctl.o tb.o switch.o cap.o path.o tunnel.o eeprom.o
thunderbolt-objs += domain.o dma_port.o icm.o property.o xdomain.o lc.o tmu.o usb4.o
+thunderbolt-objs += quirks.o
diff --git a/drivers/thunderbolt/eeprom.c b/drivers/thunderbolt/eeprom.c
index b451a5aa90b5..32838c016c4f 100644
--- a/drivers/thunderbolt/eeprom.c
+++ b/drivers/thunderbolt/eeprom.c
@@ -10,6 +10,7 @@
#include <linux/property.h>
#include <linux/slab.h>
#include "tb.h"
+#include "tb-quirks.h"

/**
* tb_eeprom_ctl_write() - write control word
@@ -599,6 +600,7 @@ int tb_drom_read(struct tb_switch *sw)
sw->uid = header->uid;
sw->vendor = header->vendor_id;
sw->device = header->model_id;
+ check_tbt_quirks(sw);

crc = tb_crc32(sw->drom + TB_DROM_DATA_START, header->data_len);
if (crc != header->data_crc32) {
diff --git a/drivers/thunderbolt/lc.c b/drivers/thunderbolt/lc.c
index bd44d50246d2..45d2a1de2069 100644
--- a/drivers/thunderbolt/lc.c
+++ b/drivers/thunderbolt/lc.c
@@ -366,3 +366,17 @@ int tb_lc_dp_sink_dealloc(struct tb_switch *sw, struct tb_port *in)
tb_port_dbg(in, "sink %d de-allocated\n", sink);
return 0;
}
+
+/**
+ * lc_force_power() - Force powers a ridge
+ * @sw: thunderbolt switch
+ *
+ * This is useful to let authentication cycle pass even without
+ * a Thunderbolt link present
+ */
+int lc_force_power(struct tb_switch *sw)
+{
+ u32 in = 0xFFFF;
+
+ return tb_sw_write(sw, &in, TB_CFG_SWITCH, TB_LC_POWER, 1);
+}
diff --git a/drivers/thunderbolt/quirks.c b/drivers/thunderbolt/quirks.c
new file mode 100644
index 000000000000..b9c5cfb97645
--- /dev/null
+++ b/drivers/thunderbolt/quirks.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Thunderbolt driver - quirks
+ *
+ * Copyright (c) 2020 Mario Limonciello <mario.limonciello@dell.com>
+ */
+
+#include "tb.h"
+#include "tb-quirks.h"
+
+static void quirk_force_power_link(struct tb_switch *sw)
+{
+ sw->quirks |= QUIRK_FORCE_POWER_LINK_CONTROLLER;
+}
+
+struct tbt_quirk {
+ u16 vendor;
+ u16 device;
+ void (*hook)(struct tb_switch *sw);
+};
+
+static struct tbt_quirk tbt_quirks[] = {
+ /* Dell WD19TB supports self-authentication on unplug */
+ { 0x00d4, 0xb070, quirk_force_power_link },
+};
+
+void check_tbt_quirks(struct tb_switch *sw)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(tbt_quirks); i++) {
+ struct tbt_quirk *q = &tbt_quirks[i];
+
+ if (sw->device == q->device &&
+ sw->vendor == q->vendor)
+ q->hook(sw);
+ }
+}
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 4c476a58db38..0576fe7c0054 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -16,6 +16,7 @@
#include <linux/vmalloc.h>

#include "tb.h"
+#include "tb-quirks.h"

/* Switch NVM support */

@@ -1542,8 +1543,8 @@ static ssize_t nvm_authenticate_show(struct device *dev,
return sprintf(buf, "%#x\n", status);
}

-static ssize_t nvm_authenticate_store(struct device *dev,
- struct device_attribute *attr, const char *buf, size_t count)
+static ssize_t nvm_authenticate_sysfs(struct device *dev, const char *buf,
+ bool disconnect)
{
struct tb_switch *sw = tb_to_switch(dev);
int val;
@@ -1581,8 +1582,12 @@ static ssize_t nvm_authenticate_store(struct device *dev,
goto exit_unlock;
}
if (val == WRITE_AND_AUTHENTICATE) {
- sw->nvm->authenticating = true;
- ret = nvm_authenticate(sw);
+ if (disconnect) {
+ ret = lc_force_power(sw);
+ } else {
+ sw->nvm->authenticating = true;
+ ret = nvm_authenticate(sw);
+ }
}
}

@@ -1592,12 +1597,36 @@ static ssize_t nvm_authenticate_store(struct device *dev,
pm_runtime_mark_last_busy(&sw->dev);
pm_runtime_put_autosuspend(&sw->dev);

+ return ret;
+}
+
+static ssize_t nvm_authenticate_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ int ret = nvm_authenticate_sysfs(dev, buf, false);
if (ret)
return ret;
return count;
}
static DEVICE_ATTR_RW(nvm_authenticate);

+static ssize_t nvm_authenticate_on_disconnect_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return nvm_authenticate_show(dev, attr, buf);
+}
+
+static ssize_t nvm_authenticate_on_disconnect_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ int ret = nvm_authenticate_sysfs(dev, buf, true);
+
+ if (ret)
+ return ret;
+ return count;
+}
+static DEVICE_ATTR_RW(nvm_authenticate_on_disconnect);
+
static ssize_t nvm_version_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -1655,6 +1684,7 @@ static struct attribute *switch_attrs[] = {
&dev_attr_generation.attr,
&dev_attr_key.attr,
&dev_attr_nvm_authenticate.attr,
+ &dev_attr_nvm_authenticate_on_disconnect.attr,
&dev_attr_nvm_version.attr,
&dev_attr_rx_speed.attr,
&dev_attr_rx_lanes.attr,
@@ -1709,6 +1739,10 @@ static umode_t switch_attr_is_visible(struct kobject *kobj,
if (tb_route(sw))
return attr->mode;
return 0;
+ } else if (attr == &dev_attr_nvm_authenticate_on_disconnect.attr) {
+ if (sw->quirks & QUIRK_FORCE_POWER_LINK_CONTROLLER)
+ return attr->mode;
+ return 0;
}

return sw->safe_mode ? 0 : attr->mode;
diff --git a/drivers/thunderbolt/tb-quirks.h b/drivers/thunderbolt/tb-quirks.h
new file mode 100644
index 000000000000..6b644eaaac40
--- /dev/null
+++ b/drivers/thunderbolt/tb-quirks.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Thunderbolt driver - quirks
+ *
+ * Copyright (c) 2020 Mario Limonciello <mario.limonciello@dell.com>
+ */
+
+
+#ifndef _TB_QUIRKS
+#define _TB_QUIRKS
+
+#define QUIRK_FORCE_POWER_LINK_CONTROLLER (1<<1)
+
+void check_tbt_quirks(struct tb_switch *sw);
+
+#endif
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 222ec19737fa..22937be69a1f 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -118,6 +118,7 @@ struct tb_switch_tmu {
* @depth: Depth in the chain this switch is connected (ICM only)
* @rpm_complete: Completion used to wait for runtime resume to
* complete (ICM only)
+ * @quirks: Quirks used for this Thunderbolt switch
*
* When the switch is being added or removed to the domain (other
* switches) you need to have domain lock held.
@@ -155,6 +156,7 @@ struct tb_switch {
u8 link;
u8 depth;
struct completion rpm_complete;
+ unsigned long quirks;
};

/**
@@ -784,6 +786,7 @@ bool tb_lc_lane_bonding_possible(struct tb_switch *sw);
bool tb_lc_dp_sink_query(struct tb_switch *sw, struct tb_port *in);
int tb_lc_dp_sink_alloc(struct tb_switch *sw, struct tb_port *in);
int tb_lc_dp_sink_dealloc(struct tb_switch *sw, struct tb_port *in);
+int lc_force_power(struct tb_switch *sw);

static inline int tb_route_length(u64 route)
{
diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index c29c5075525a..9a2fab9c5346 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -379,6 +379,7 @@ struct tb_regs_hop {
#define TB_LC_SNK_ALLOCATION_SNK1_SHIFT 4
#define TB_LC_SNK_ALLOCATION_SNK1_MASK GENMASK(7, 4)
#define TB_LC_SNK_ALLOCATION_SNK1_CM 0x1
+#define TB_LC_POWER 0x740

/* Link controller registers */
#define TB_LC_PORT_ATTR 0x8d
--
2.25.1
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