[PATCH] thunderbolt: Make PCIe NHI support opt-in
From: Konrad Dybcio
Date: Tue Sep 15 2026 - 13:07:49 EST
From: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
With more implementations coming in, one may desire not to enable
support for the PCIe-attached NHIs. Allow it to be built as a module
atop the framework.
Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
---
The diff came out a little messy.. compile-tested with CONFIG_PCI=n and
tested USB4_PCIE=m/=y on a NUC with an Alpine Ridge controller
---
drivers/thunderbolt/Kconfig | 11 ++++++++++-
drivers/thunderbolt/Makefile | 7 +++++--
drivers/thunderbolt/ctl.c | 6 +++++-
drivers/thunderbolt/domain.c | 14 ++++++++++++--
drivers/thunderbolt/nhi.c | 18 +++++++++++-------
drivers/thunderbolt/nhi.h | 2 ++
drivers/thunderbolt/pci.c | 39 ++++++++++++++-------------------------
drivers/thunderbolt/switch.c | 9 +++++++++
drivers/thunderbolt/tb.h | 2 --
drivers/thunderbolt/tunnel.c | 1 +
drivers/thunderbolt/xdomain.c | 5 +++++
11 files changed, 74 insertions(+), 40 deletions(-)
diff --git a/drivers/thunderbolt/Kconfig b/drivers/thunderbolt/Kconfig
index 294b3227a545..81fca3bfcdd7 100644
--- a/drivers/thunderbolt/Kconfig
+++ b/drivers/thunderbolt/Kconfig
@@ -1,7 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
menuconfig USB4
tristate "Unified support for USB4 and Thunderbolt"
- depends on PCI
select APPLE_PROPERTIES if EFI_STUB && X86
select CRC32
select CRYPTO_LIB_SHA256
@@ -18,6 +17,16 @@ menuconfig USB4
if USB4
+config USB4_PCIE
+ depends on PCI
+ tristate "Support for PCIe-attached USB4 and Thunderbolt controllers"
+ help
+ Say Y here to add support for the USB4 and Thunderbolt host
+ routers attached over the PCIe bus, commonly found on x86 PCs.
+
+ To compile this driver a module, choose M here. The module will be
+ called thunderbolt_pcie.
+
config USB4_CONFIGFS
def_tristate USB4
depends on CONFIGFS_FS && !(USB4=y && CONFIGFS_FS=m)
diff --git a/drivers/thunderbolt/Makefile b/drivers/thunderbolt/Makefile
index beb054c3126b..fc808c6b23e6 100644
--- a/drivers/thunderbolt/Makefile
+++ b/drivers/thunderbolt/Makefile
@@ -1,10 +1,13 @@
# SPDX-License-Identifier: GPL-2.0-only
ccflags-y := -I$(src)
obj-${CONFIG_USB4} := thunderbolt.o
-thunderbolt-objs := nhi.o ctl.o tb.o switch.o cap.o pci.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 := nhi.o ctl.o tb.o switch.o cap.o path.o tunnel.o eeprom.o
+thunderbolt-objs += domain.o dma_port.o property.o xdomain.o lc.o tmu.o usb4.o
thunderbolt-objs += usb4_port.o nvm.o retimer.o quirks.o clx.o
+obj-${CONFIG_USB4_PCIE} += thunderbolt_pcie.o
+thunderbolt_pcie-y := pci.o icm.o
+
thunderbolt-${CONFIG_ACPI} += acpi.o
thunderbolt-$(CONFIG_DEBUG_FS) += debugfs.o
thunderbolt-$(CONFIG_USB4_CONFIGFS) += configfs.o
diff --git a/drivers/thunderbolt/ctl.c b/drivers/thunderbolt/ctl.c
index 965988b18608..96717a0a94b1 100644
--- a/drivers/thunderbolt/ctl.c
+++ b/drivers/thunderbolt/ctl.c
@@ -9,7 +9,6 @@
#include <linux/crc32.h>
#include <linux/delay.h>
#include <linux/slab.h>
-#include <linux/pci.h>
#include <linux/dmapool.h>
#include <linux/workqueue.h>
@@ -96,6 +95,7 @@ struct tb_cfg_request *tb_cfg_request_alloc(void)
return req;
}
+EXPORT_SYMBOL_GPL(tb_cfg_request_alloc);
/**
* tb_cfg_request_get() - Increase refcount of a request
@@ -128,6 +128,7 @@ void tb_cfg_request_put(struct tb_cfg_request *req)
kref_put(&req->kref, tb_cfg_request_destroy);
mutex_unlock(&tb_cfg_request_lock);
}
+EXPORT_SYMBOL_GPL(tb_cfg_request_put);
static int tb_cfg_request_enqueue(struct tb_ctl *ctl,
struct tb_cfg_request *req)
@@ -575,6 +576,7 @@ int tb_cfg_request(struct tb_ctl *ctl, struct tb_cfg_request *req,
tb_cfg_request_dequeue(req);
return ret;
}
+EXPORT_SYMBOL_GPL(tb_cfg_request);
/**
* tb_cfg_request_cancel() - Cancel a control request
@@ -634,6 +636,7 @@ struct tb_cfg_result tb_cfg_request_sync(struct tb_ctl *ctl,
return req->result;
}
+EXPORT_SYMBOL_GPL(tb_cfg_request_sync);
/* public interface, alloc/start/stop/free */
@@ -1009,6 +1012,7 @@ struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer,
memcpy(buffer, &reply.data, 4 * length);
return res;
}
+EXPORT_SYMBOL_GPL(tb_cfg_read_raw);
/**
* tb_cfg_write_raw() - write from buffer into config space
diff --git a/drivers/thunderbolt/domain.c b/drivers/thunderbolt/domain.c
index 12c88509a54f..1c76fd8151ca 100644
--- a/drivers/thunderbolt/domain.c
+++ b/drivers/thunderbolt/domain.c
@@ -313,6 +313,7 @@ const struct bus_type tb_bus_type = {
.remove = tb_service_remove,
.shutdown = tb_service_shutdown,
};
+EXPORT_SYMBOL_GPL(tb_bus_type);
static void tb_domain_release(struct device *dev)
{
@@ -421,6 +422,7 @@ struct tb *tb_domain_alloc(struct tb_nhi *nhi, int timeout_msec, size_t privsize
return NULL;
}
+EXPORT_SYMBOL_GPL(tb_domain_alloc);
/**
* tb_domain_add() - Add domain to the system
@@ -514,6 +516,7 @@ void tb_domain_remove(struct tb *tb)
device_unregister(&tb->dev);
}
+EXPORT_SYMBOL_GPL(tb_domain_remove);
/**
* tb_domain_suspend_noirq() - Suspend a domain
@@ -904,8 +907,9 @@ int tb_domain_unregister_unplugged_xdomains(struct tb *tb)
return ctx.n;
}
+EXPORT_SYMBOL_GPL(tb_domain_unregister_unplugged_xdomains);
-int tb_domain_init(void)
+static int __init tb_domain_init(void)
{
int ret;
@@ -931,7 +935,7 @@ int tb_domain_init(void)
return ret;
}
-void tb_domain_exit(void)
+static void __exit tb_domain_exit(void)
{
bus_unregister(&tb_bus_type);
ida_destroy(&tb_domain_ida);
@@ -941,3 +945,9 @@ void tb_domain_exit(void)
tb_debugfs_exit();
tb_configfs_exit();
}
+
+postcore_initcall(tb_domain_init);
+module_exit(tb_domain_exit);
+
+MODULE_DESCRIPTION("Thunderbolt/USB4 core driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index 020db5a1f029..9b1165b2a484 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -548,6 +548,7 @@ irqreturn_t ring_msix(int irq, void *data)
return IRQ_HANDLED;
}
+EXPORT_SYMBOL_GPL(ring_msix);
static int nhi_alloc_hop(struct tb_nhi *nhi, struct tb_ring *ring)
{
@@ -1001,6 +1002,7 @@ int nhi_mailbox_cmd(struct tb_nhi *nhi, enum nhi_mailbox_cmd cmd, u32 data)
return 0;
}
+EXPORT_SYMBOL_GPL(nhi_mailbox_cmd);
/**
* nhi_mailbox_mode() - Return current firmware operation mode
@@ -1021,6 +1023,7 @@ enum nhi_fw_mode nhi_mailbox_mode(struct tb_nhi *nhi)
return (enum nhi_fw_mode)val;
}
+EXPORT_SYMBOL_GPL(nhi_mailbox_mode);
void nhi_interrupt_work(struct work_struct *work)
{
@@ -1071,6 +1074,7 @@ void nhi_interrupt_work(struct work_struct *work)
}
spin_unlock_irq(&nhi->lock);
}
+EXPORT_SYMBOL_GPL(nhi_interrupt_work);
irqreturn_t nhi_msi(int irq, void *data)
{
@@ -1078,6 +1082,7 @@ irqreturn_t nhi_msi(int irq, void *data)
schedule_work(&nhi->interrupt_work);
return IRQ_HANDLED;
}
+EXPORT_SYMBOL_GPL(nhi_msi);
static int __nhi_suspend_noirq(struct device *dev, bool wakeup)
{
@@ -1235,6 +1240,7 @@ void nhi_shutdown(struct tb_nhi *nhi)
if (nhi->ops->shutdown)
nhi->ops->shutdown(nhi);
}
+EXPORT_SYMBOL_GPL(nhi_shutdown);
static void nhi_reset(struct tb_nhi *nhi)
{
@@ -1292,6 +1298,7 @@ void nhi_reset_interface(struct tb_nhi *nhi)
/* Wait for tHIReset (10 ms) to complete */
usleep_range(10000, 20000);
}
+EXPORT_SYMBOL_GPL(nhi_reset_interface);
static struct tb *nhi_select_cm(struct tb_nhi *nhi)
{
@@ -1302,13 +1309,8 @@ static struct tb *nhi_select_cm(struct tb_nhi *nhi)
* USB4 case is simple. If we got control of any of the
* capabilities, we use software CM.
*/
- if (!tb_acpi_is_native()) {
- /*
- * Either firmware based CM is running (we did not get
- * control from the firmware) or this is pre-USB4 PC so
- * try first firmware CM and then fallback to software CM.
- */
- tb = icm_probe(nhi);
+ if (!tb_acpi_is_native() && nhi->ops->select_cm) {
+ tb = nhi->ops->select_cm(nhi);
if (tb)
return tb;
}
@@ -1411,6 +1413,7 @@ int nhi_probe(struct tb_nhi *nhi)
return 0;
}
+EXPORT_SYMBOL_GPL(nhi_probe);
/*
* The tunneled pci bridges are siblings of us. Use resume_noirq to reenable
@@ -1433,3 +1436,4 @@ const struct dev_pm_ops nhi_pm_ops = {
.runtime_suspend = nhi_runtime_suspend,
.runtime_resume = nhi_runtime_resume,
};
+EXPORT_SYMBOL_GPL(nhi_pm_ops);
diff --git a/drivers/thunderbolt/nhi.h b/drivers/thunderbolt/nhi.h
index b2e2e2c413b2..475ee8615edf 100644
--- a/drivers/thunderbolt/nhi.h
+++ b/drivers/thunderbolt/nhi.h
@@ -56,6 +56,7 @@ extern const struct dev_pm_ops nhi_pm_ops;
* @is_present: Whether the device is currently present on the parent bus
* @init_interrupts: NHI specific interrupt initialization hook
* @reset_interface: Resets the host interface
+ * @select_cm: optional hook to select a custom CM
*/
struct tb_nhi_ops {
int (*init)(struct tb_nhi *nhi);
@@ -72,6 +73,7 @@ struct tb_nhi_ops {
bool (*is_present)(struct tb_nhi *nhi);
int (*init_interrupts)(struct tb_nhi *nhi);
void (*reset_interface)(struct tb_nhi *nhi);
+ struct tb * (*select_cm)(struct tb_nhi *nhi);
};
/*
diff --git a/drivers/thunderbolt/pci.c b/drivers/thunderbolt/pci.c
index e40d4d6af071..f215ef7aa336 100644
--- a/drivers/thunderbolt/pci.c
+++ b/drivers/thunderbolt/pci.c
@@ -348,6 +348,16 @@ static bool nhi_pci_is_present(struct tb_nhi *nhi)
return pci_device_is_present(to_pci_dev(nhi->dev));
}
+static struct tb *nhi_pci_select_cm(struct tb_nhi *nhi)
+{
+ /*
+ * Either the firmware-based CM is running (we did not get
+ * control from the firmware) or this is a pre-USB4 PC, so
+ * first try using the firmware CM and then fallback to software CM.
+ */
+ return icm_probe(nhi);
+}
+
static const struct tb_nhi_ops pci_nhi_default_ops = {
.add_links = nhi_pci_add_links,
.pre_nvm_auth = nhi_pci_start_dma_port,
@@ -358,6 +368,7 @@ static const struct tb_nhi_ops pci_nhi_default_ops = {
.is_present = nhi_pci_is_present,
.init_interrupts = nhi_pci_init_msi,
.reset_interface = nhi_reset_interface,
+ .select_cm = nhi_pci_select_cm,
};
/* Ice Lake specific NHI operations */
@@ -577,6 +588,7 @@ static const struct tb_nhi_ops icl_nhi_ops = {
.is_present = nhi_pci_is_present,
.init_interrupts = nhi_pci_init_msi,
.reset_interface = nhi_reset_interface,
+ .select_cm = nhi_pci_select_cm,
};
static int nhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
@@ -738,7 +750,7 @@ static struct pci_device_id nhi_ids[] = {
};
MODULE_DEVICE_TABLE(pci, nhi_ids);
-MODULE_DESCRIPTION("Thunderbolt/USB4 core driver");
+MODULE_DESCRIPTION("PCIe-attached Thunderbolt/USB4 host interface driver");
MODULE_LICENSE("GPL");
static struct pci_driver nhi_driver = {
@@ -749,27 +761,4 @@ static struct pci_driver nhi_driver = {
.shutdown = nhi_pci_shutdown,
.driver.pm = &nhi_pm_ops,
};
-
-static int __init nhi_init(void)
-{
- int ret;
-
- ret = tb_domain_init();
- if (ret)
- return ret;
-
- ret = pci_register_driver(&nhi_driver);
- if (ret)
- tb_domain_exit();
-
- return ret;
-}
-
-static void __exit nhi_unload(void)
-{
- pci_unregister_driver(&nhi_driver);
- tb_domain_exit();
-}
-
-rootfs_initcall(nhi_init);
-module_exit(nhi_unload);
+module_pci_driver(nhi_driver)
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index d22d8db8f890..7ff3da79da76 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -2396,6 +2396,7 @@ const struct device_type tb_switch_type = {
.uevent = tb_switch_uevent,
.pm = &tb_switch_pm_ops,
};
+EXPORT_SYMBOL_GPL(tb_switch_type);
static int tb_switch_get_generation(struct tb_switch *sw)
{
@@ -2571,6 +2572,7 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
return ERR_PTR(ret);
}
+EXPORT_SYMBOL_GPL(tb_switch_alloc);
/**
* tb_switch_alloc_safe_mode() - allocate a switch that is in safe mode
@@ -2610,6 +2612,7 @@ tb_switch_alloc_safe_mode(struct tb *tb, struct device *parent, u64 route)
return sw;
}
+EXPORT_SYMBOL_GPL(tb_switch_alloc_safe_mode);
/**
* tb_switch_configure() - Uploads configuration to the switch
@@ -3438,6 +3441,7 @@ int tb_switch_add(struct tb_switch *sw)
return ret;
}
+EXPORT_SYMBOL_GPL(tb_switch_add);
/**
* tb_switch_remove() - Remove and release a switch
@@ -3483,6 +3487,7 @@ void tb_switch_remove(struct tb_switch *sw)
dev_info(&sw->dev, "device disconnected\n");
device_unregister(&sw->dev);
}
+EXPORT_SYMBOL_GPL(tb_switch_remove);
/**
* tb_sw_set_unplugged() - set is_unplugged on switch and downstream switches
@@ -3828,6 +3833,7 @@ struct tb_switch *tb_switch_find_by_link_depth(struct tb *tb, u8 link, u8 depth)
return NULL;
}
+EXPORT_SYMBOL_GPL(tb_switch_find_by_link_depth);
/**
* tb_switch_find_by_uuid() - Find switch by UUID
@@ -3854,6 +3860,7 @@ struct tb_switch *tb_switch_find_by_uuid(struct tb *tb, const uuid_t *uuid)
return NULL;
}
+EXPORT_SYMBOL_GPL(tb_switch_find_by_uuid);
/**
* tb_switch_find_by_route() - Find switch by route string
@@ -3883,6 +3890,7 @@ struct tb_switch *tb_switch_find_by_route(struct tb *tb, u64 route)
return NULL;
}
+EXPORT_SYMBOL_GPL(tb_switch_find_by_route);
/**
* tb_switch_find_port() - return the first port of @type on @sw or NULL
@@ -3903,6 +3911,7 @@ struct tb_port *tb_switch_find_port(struct tb_switch *sw,
return NULL;
}
+EXPORT_SYMBOL_GPL(tb_switch_find_port);
/*
* Can be used for read/write a specified PCIe bridge for any Thunderbolt 3
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index c112954ce3fd..12dad4097a8f 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -768,8 +768,6 @@ extern const struct device_type tb_retimer_type;
extern const struct device_type tb_switch_type;
extern const struct device_type usb4_port_device_type;
-int tb_domain_init(void);
-void tb_domain_exit(void);
int tb_xdomain_init(void);
void tb_xdomain_exit(void);
diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
index ffd2d04b3bfa..fdaff55baead 100644
--- a/drivers/thunderbolt/tunnel.c
+++ b/drivers/thunderbolt/tunnel.c
@@ -273,6 +273,7 @@ void tb_tunnel_event(struct tb *tb, enum tb_tunnel_event event,
kfree(envp[1]);
kfree(envp[0]);
}
+EXPORT_SYMBOL_GPL(tb_tunnel_event);
static inline void tb_tunnel_set_active(struct tb_tunnel *tunnel, bool active)
{
diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
index b187a60663f5..af82b86a0348 100644
--- a/drivers/thunderbolt/xdomain.c
+++ b/drivers/thunderbolt/xdomain.c
@@ -86,6 +86,7 @@ bool tb_is_xdomain_enabled(void)
{
return tb_xdomain_enabled && tb_acpi_is_xdomain_allowed();
}
+EXPORT_SYMBOL_GPL(tb_is_xdomain_enabled);
static bool tb_xdomain_match(const struct tb_cfg_request *req,
const struct ctl_pkg *pkg)
@@ -2196,6 +2197,7 @@ struct tb_xdomain *tb_xdomain_alloc(struct tb *tb, struct device *parent,
return NULL;
}
+EXPORT_SYMBOL_GPL(tb_xdomain_alloc);
/**
* tb_xdomain_add() - Add XDomain to the bus
@@ -2211,6 +2213,7 @@ void tb_xdomain_add(struct tb_xdomain *xd)
/* Start exchanging properties with the other host */
start_handshake(xd);
}
+EXPORT_SYMBOL_GPL(tb_xdomain_add);
static int unregister_service(struct device *dev, void *data)
{
@@ -2270,6 +2273,7 @@ void tb_xdomain_unregister(struct tb_xdomain *xd)
dev_info(&xd->dev, "host disconnected\n");
device_unregister(&xd->dev);
}
+EXPORT_SYMBOL_GPL(tb_xdomain_remove);
/**
* tb_xdomain_lane_bonding_enable() - Enable lane bonding on XDomain
@@ -2593,6 +2597,7 @@ struct tb_xdomain *tb_xdomain_find_by_link_depth(struct tb *tb, u8 link,
xd = switch_find_xdomain(tb->root_switch, &lookup);
return tb_xdomain_get(xd);
}
+EXPORT_SYMBOL_GPL(tb_xdomain_find_by_link_depth);
/**
* tb_xdomain_find_by_route() - Find an XDomain by route string
---
base-commit: 1a1de54f7369cd2b5bac0f265910e60ad3a6b4c3
change-id: 20260915-topic-tbt_pcie_optional-2af6de7e47f3
Best regards,
--
Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>