[PATCH v8 7/9] PCI/IDE: Add IDE establishment helpers

Dan Williams
2025-10-31T21:29:07Z

There are two components to establishing an encrypted link, provisioning
the stream in Partner Port config-space, and programming the keys into
the link layer via IDE_KM (IDE Key Management). This new library,
drivers/pci/ide.c, enables the former. IDE_KM, via a TSM low-level
driver, is saved for later.

With the platform TSM implementations of SEV-TIO and TDX Connect in mind
this library abstracts small differences in those implementations. For
example, TDX Connect handles Root Port register setup while SEV-TIO
expects System Software to update the Root Port registers. This is the
rationale for fine-grained 'setup' + 'enable' verbs.

The other design detail for TSM-coordinated IDE establishment is that
the TSM may manage allocation of Stream IDs, this is why the Stream ID
value is passed in to pci_ide_stream_setup().

The flow is:

pci_ide_stream_alloc():
Allocate a Selective IDE Stream Register Block in each Partner Port
(Endpoint + Root Port), and reserve a host bridge / platform stream
slot. Gather Partner Port specific stream settings like Requester ID.

pci_ide_stream_register():
Publish the stream in sysfs after allocating a Stream ID. In the TSM
case the TSM allocates the Stream ID for the Partner Port pair.

pci_ide_stream_setup():
Program the stream settings to a Partner Port. Caller is responsible
for optionally calling this for the Root Port as well if the TSM
implementation requires it.

pci_ide_stream_enable():
Enable the stream after IDE_KM.

In support of system administrators auditing where platform, Root Port,
and Endpoint IDE stream resources are being spent, the allocated stream
is reflected as a symlink from the host bridge to the endpoint with the
name:

stream%d.%d.%d

Where the tuple of integers reflects the allocated platform, Root Port,
and Endpoint stream index (Selective IDE Stream Register Block) values.

Thanks to Wu Hao for a draft implementation of this infrastructure.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Samuel Ortiz <sameo@rivosinc.com>
Co-developed-by: Alexey Kardashevskiy <aik@amd.com>
Signed-off-by: Alexey Kardashevskiy <aik@amd.com>
Co-developed-by: Xu Yilun <yilun.xu@linux.intel.com>
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
.../ABI/testing/sysfs-devices-pci-host-bridge | 14 +
drivers/pci/pci.h | 2 +
include/linux/pci-ide.h | 78 ++++
include/linux/pci.h | 6 +
drivers/pci/ide.c | 428 ++++++++++++++++++
drivers/pci/probe.c | 1 +
6 files changed, 529 insertions(+)
create mode 100644 include/linux/pci-ide.h

diff --git a/Documentation/ABI/testing/sysfs-devices-pci-host-bridge b/Documentation/ABI/testing/sysfs-devices-pci-host-bridge
index 8c3a652799f1..2c66e5bb2bf8 100644
--- a/Documentation/ABI/testing/sysfs-devices-pci-host-bridge
+++ b/Documentation/ABI/testing/sysfs-devices-pci-host-bridge
@@ -17,3 +17,17 @@ Description:
PNP0A08 (/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00). See
/sys/devices/pciDDDD:BB entry for details about the DDDD:BB
format.
+
+What: pciDDDD:BB/streamH.R.E
+Contact: linux-pci@vger.kernel.org
+Description:
+ (RO) When a platform has established a secure connection, PCIe
+ IDE, between two Partner Ports, this symlink appears. A stream
+ consumes a Stream ID slot in each of the Host bridge (H), Root
+ Port (R) and Endpoint (E). The link points to the Endpoint PCI
+ device in the Selective IDE Stream pairing. Specifically, "R"
+ and "E" represent the assigned Selective IDE Stream Register
+ Block in the Root Port and Endpoint, and "H" represents a
+ platform specific pool of stream resources shared by the Root
+ Ports in a host bridge. See /sys/devices/pciDDDD:BB entry for
+ details about the DDDD:BB format.
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 6e4cc1c9aa58..d3f16be40102 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -615,8 +615,10 @@ static inline void pci_doe_sysfs_teardown(struct pci_dev *pdev) { }

#ifdef CONFIG_PCI_IDE
void pci_ide_init(struct pci_dev *dev);
+void pci_ide_init_host_bridge(struct pci_host_bridge *hb);
#else
static inline void pci_ide_init(struct pci_dev *dev) { }
+static inline void pci_ide_init_host_bridge(struct pci_host_bridge *hb) { }
#endif

#ifdef CONFIG_PCI_TSM
diff --git a/include/linux/pci-ide.h b/include/linux/pci-ide.h
new file mode 100644
index 000000000000..e638f9429bf9
--- /dev/null
+++ b/include/linux/pci-ide.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common helpers for drivers (e.g. low-level PCI/TSM drivers) implementing the
+ * IDE key management protocol (IDE_KM) as defined by:
+ * PCIe r7.0 section 6.33 Integrity & Data Encryption (IDE)
+ *
+ * Copyright(c) 2024-2025 Intel Corporation. All rights reserved.
+ */
+
+#ifndef __PCI_IDE_H__
+#define __PCI_IDE_H__
+
+enum pci_ide_partner_select {
+ PCI_IDE_EP,
+ PCI_IDE_RP,
+ PCI_IDE_PARTNER_MAX,
+ /*
+ * In addition to the resources in each partner port the
+ * platform / host-bridge additionally has a Stream ID pool that
+ * it shares across root ports. Let pci_ide_stream_alloc() use
+ * the alloc_stream_index() helper as endpoints and root ports.
+ */
+ PCI_IDE_HB = PCI_IDE_PARTNER_MAX,
+};
+
+/**
+ * struct pci_ide_partner - Per port pair Selective IDE Stream settings
+ * @rid_start: Partner Port Requester ID range start
+ * @rid_end: Partner Port Requester ID range end
+ * @stream_index: Selective IDE Stream Register Block selection
+ * @default_stream: Endpoint uses this stream for all upstream TLPs regardless of
+ * address and RID association registers
+ * @setup: flag to track whether to run pci_ide_stream_teardown() for this
+ * partner slot
+ * @enable: flag whether to run pci_ide_stream_disable() for this partner slot
+ */
+struct pci_ide_partner {
+ u16 rid_start;
+ u16 rid_end;
+ u8 stream_index;
+ unsigned int default_stream:1;
+ unsigned int setup:1;
+ unsigned int enable:1;
+};
+
+/**
+ * struct pci_ide - PCIe Selective IDE Stream descriptor
+ * @pdev: PCIe Endpoint in the pci_ide_partner pair
+ * @partner: per-partner settings
+ * @host_bridge_stream: allocated from host bridge @ide_stream_ida pool
+ * @stream_id: unique Stream ID (within Partner Port pairing)
+ * @name: name of the established Selective IDE Stream in sysfs
+ *
+ * Negative @stream_id values indicate "uninitialized" on the
+ * expectation that with TSM established IDE the TSM owns the stream_id
+ * allocation.
+ */
+struct pci_ide {
+ struct pci_dev *pdev;
+ struct pci_ide_partner partner[PCI_IDE_PARTNER_MAX];
+ u8 host_bridge_stream;
+ int stream_id;
+ const char *name;
+};
+
+struct pci_ide_partner *pci_ide_to_settings(struct pci_dev *pdev,
+ struct pci_ide *ide);
+struct pci_ide *pci_ide_stream_alloc(struct pci_dev *pdev);
+void pci_ide_stream_free(struct pci_ide *ide);
+int pci_ide_stream_register(struct pci_ide *ide);
+void pci_ide_stream_unregister(struct pci_ide *ide);
+void pci_ide_stream_setup(struct pci_dev *pdev, struct pci_ide *ide);
+void pci_ide_stream_teardown(struct pci_dev *pdev, struct pci_ide *ide);
+int pci_ide_stream_enable(struct pci_dev *pdev, struct pci_ide *ide);
+void pci_ide_stream_disable(struct pci_dev *pdev, struct pci_ide *ide);
+void pci_ide_stream_release(struct pci_ide *ide);
+DEFINE_FREE(pci_ide_stream_release, struct pci_ide *, if (_T) pci_ide_stream_release(_T))
+#endif /* __PCI_IDE_H__ */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index ea94799c81b0..2c8dbae4916c 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -545,6 +545,8 @@ struct pci_dev {
u16 ide_cap; /* Link Integrity & Data Encryption */
u8 nr_ide_mem; /* Address association resources for streams */
u8 nr_link_ide; /* Link Stream count (Selective Stream offset) */
+ u16 nr_sel_ide; /* Selective Stream count (register block allocator) */
+ struct ida ide_stream_ida;
unsigned int ide_cfg:1; /* Config cycles over IDE */
unsigned int ide_tee_limit:1; /* Disallow T=0 traffic over IDE */
#endif
@@ -614,6 +616,10 @@ struct pci_host_bridge {
int domain_nr;
struct list_head windows; /* resource_entry */
struct list_head dma_ranges; /* dma ranges resource list */
+#ifdef CONFIG_PCI_IDE
+ u16 nr_ide_streams; /* Max streams possibly active in @ide_stream_ida */
+ struct ida ide_stream_ida;
+#endif
u8 (*swizzle_irq)(struct pci_dev *, u8 *); /* Platform IRQ swizzler */
int (*map_irq)(const struct pci_dev *, u8, u8);
void (*release_fn)(struct pci_host_bridge *);
diff --git a/drivers/pci/ide.c b/drivers/pci/ide.c
index 26866edf91b4..7643840738fe 100644
--- a/drivers/pci/ide.c
+++ b/drivers/pci/ide.c
@@ -5,8 +5,12 @@

#define dev_fmt(fmt) "PCI/IDE: " fmt
#include <linux/bitfield.h>
+#include <linux/bitops.h>
#include <linux/pci.h>
+#include <linux/pci-ide.h>
#include <linux/pci_regs.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>

#include "pci.h"

@@ -23,12 +27,25 @@ static int __sel_ide_offset(u16 ide_cap, u8 nr_link_ide, u8 stream_index,
return offset + stream_index * PCI_IDE_SEL_BLOCK_SIZE(nr_ide_mem);
}

+static int sel_ide_offset(struct pci_dev *pdev,
+ struct pci_ide_partner *settings)
+{
+ return __sel_ide_offset(pdev->ide_cap, pdev->nr_link_ide,
+ settings->stream_index, pdev->nr_ide_mem);
+}
+
void pci_ide_init(struct pci_dev *pdev)
{
u16 nr_link_ide, nr_ide_mem, nr_streams;
u16 ide_cap;
u32 val;

+ /*
+ * Unconditionally init so that ida idle state is consistent with
+ * pdev->ide_cap.
+ */
+ ida_init(&pdev->ide_stream_ida);
+
if (!pci_is_pcie(pdev))
return;

@@ -84,5 +101,416 @@ void pci_ide_init(struct pci_dev *pdev)

pdev->ide_cap = ide_cap;
pdev->nr_link_ide = nr_link_ide;
+ pdev->nr_sel_ide = nr_streams;
pdev->nr_ide_mem = nr_ide_mem;
}
+
+struct stream_index {
+ struct ida *ida;
+ u8 stream_index;
+};
+
+static void free_stream_index(struct stream_index *stream)
+{
+ ida_free(stream->ida, stream->stream_index);
+}
+
+DEFINE_FREE(free_stream, struct stream_index *, if (_T) free_stream_index(_T))
+static struct stream_index *alloc_stream_index(struct ida *ida, u16 max,
+ struct stream_index *stream)
+{
+ int id;
+
+ if (!max)
+ return NULL;
+
+ id = ida_alloc_max(ida, max - 1, GFP_KERNEL);
+ if (id < 0)
+ return NULL;
+
+ *stream = (struct stream_index) {
+ .ida = ida,
+ .stream_index = id,
+ };
+ return stream;
+}
+
+/**
+ * pci_ide_stream_alloc() - Reserve stream indices and probe for settings
+ * @pdev: IDE capable PCIe Endpoint Physical Function
+ *
+ * Retrieve the Requester ID range of @pdev for programming its Root
+ * Port IDE RID Association registers, and conversely retrieve the
+ * Requester ID of the Root Port for programming @pdev's IDE RID
+ * Association registers.
+ *
+ * Allocate a Selective IDE Stream Register Block instance per port.
+ *
+ * Allocate a platform stream resource from the associated host bridge.
+ * Retrieve stream association parameters for Requester ID range and
+ * address range restrictions for the stream.
+ */
+struct pci_ide *pci_ide_stream_alloc(struct pci_dev *pdev)
+{
+ /* EP, RP, + HB Stream allocation */
+ struct stream_index __stream[PCI_IDE_HB + 1];
+ struct pci_host_bridge *hb;
+ struct pci_dev *rp;
+ int num_vf, rid_end;
+
+ if (!pci_is_pcie(pdev))
+ return NULL;
+
+ if (pci_pcie_type(pdev) != PCI_EXP_TYPE_ENDPOINT)
+ return NULL;
+
+ if (!pdev->ide_cap)
+ return NULL;
+
+ struct pci_ide *ide __free(kfree) = kzalloc(sizeof(*ide), GFP_KERNEL);
+ if (!ide)
+ return NULL;
+
+ hb = pci_find_host_bridge(pdev->bus);
+ struct stream_index *hb_stream __free(free_stream) = alloc_stream_index(
+ &hb->ide_stream_ida, hb->nr_ide_streams, &__stream[PCI_IDE_HB]);
+ if (!hb_stream)
+ return NULL;
+
+ rp = pcie_find_root_port(pdev);
+ struct stream_index *rp_stream __free(free_stream) = alloc_stream_index(
+ &rp->ide_stream_ida, rp->nr_sel_ide, &__stream[PCI_IDE_RP]);
+ if (!rp_stream)
+ return NULL;
+
+ struct stream_index *ep_stream __free(free_stream) = alloc_stream_index(
+ &pdev->ide_stream_ida, pdev->nr_sel_ide, &__stream[PCI_IDE_EP]);
+ if (!ep_stream)
+ return NULL;
+
+ /* for SR-IOV case, cover all VFs */
+ num_vf = pci_num_vf(pdev);
+ if (num_vf)
+ rid_end = PCI_DEVID(pci_iov_virtfn_bus(pdev, num_vf),
+ pci_iov_virtfn_devfn(pdev, num_vf));
+ else
+ rid_end = pci_dev_id(pdev);
+
+ *ide = (struct pci_ide) {
+ .pdev = pdev,
+ .partner = {
+ [PCI_IDE_EP] = {
+ .rid_start = pci_dev_id(rp),
+ .rid_end = pci_dev_id(rp),
+ .stream_index = no_free_ptr(ep_stream)->stream_index,
+ },
+ [PCI_IDE_RP] = {
+ .rid_start = pci_dev_id(pdev),
+ .rid_end = rid_end,
+ .stream_index = no_free_ptr(rp_stream)->stream_index,
+ },
+ },
+ .host_bridge_stream = no_free_ptr(hb_stream)->stream_index,
+ .stream_id = -1,
+ };
+
+ return_ptr(ide);
+}
+EXPORT_SYMBOL_GPL(pci_ide_stream_alloc);
+
+/**
+ * pci_ide_stream_free() - unwind pci_ide_stream_alloc()
+ * @ide: idle IDE settings descriptor
+ *
+ * Free all of the stream index (register block) allocations acquired by
+ * pci_ide_stream_alloc(). The stream represented by @ide is assumed to
+ * be unregistered and not instantiated in any device.
+ */
+void pci_ide_stream_free(struct pci_ide *ide)
+{
+ struct pci_dev *pdev = ide->pdev;
+ struct pci_dev *rp = pcie_find_root_port(pdev);
+ struct pci_host_bridge *hb = pci_find_host_bridge(pdev->bus);
+
+ ida_free(&pdev->ide_stream_ida, ide->partner[PCI_IDE_EP].stream_index);
+ ida_free(&rp->ide_stream_ida, ide->partner[PCI_IDE_RP].stream_index);
+ ida_free(&hb->ide_stream_ida, ide->host_bridge_stream);
+ kfree(ide);
+}
+EXPORT_SYMBOL_GPL(pci_ide_stream_free);
+
+/**
+ * pci_ide_stream_release() - unwind and release an @ide context
+ * @ide: partially or fully registered IDE settings descriptor
+ *
+ * In support of automatic cleanup of IDE setup routines perform IDE
+ * teardown in expected reverse order of setup and with respect to which
+ * aspects of IDE setup have successfully completed.
+ *
+ * Be careful that setup order mirrors this shutdown order. Otherwise,
+ * open code releasing the IDE context.
+ */
+void pci_ide_stream_release(struct pci_ide *ide)
+{
+ struct pci_dev *pdev = ide->pdev;
+ struct pci_dev *rp = pcie_find_root_port(pdev);
+
+ if (ide->partner[PCI_IDE_RP].enable)
+ pci_ide_stream_disable(rp, ide);
+
+ if (ide->partner[PCI_IDE_EP].enable)
+ pci_ide_stream_disable(pdev, ide);
+
+ if (ide->partner[PCI_IDE_RP].setup)
+ pci_ide_stream_teardown(rp, ide);
+
+ if (ide->partner[PCI_IDE_EP].setup)
+ pci_ide_stream_teardown(pdev, ide);
+
+ if (ide->name)
+ pci_ide_stream_unregister(ide);
+
+ pci_ide_stream_free(ide);
+}
+EXPORT_SYMBOL_GPL(pci_ide_stream_release);
+
+/**
+ * pci_ide_stream_register() - Prepare to activate an IDE Stream
+ * @ide: IDE settings descriptor
+ *
+ * After a Stream ID has been acquired for @ide, record the presence of
+ * the stream in sysfs. The expectation is that @ide is immutable while
+ * registered.
+ */
+int pci_ide_stream_register(struct pci_ide *ide)
+{
+ struct pci_dev *pdev = ide->pdev;
+ struct pci_host_bridge *hb = pci_find_host_bridge(pdev->bus);
+ u8 ep_stream, rp_stream;
+ int rc;
+
+ if (ide->stream_id < 0 || ide->stream_id > U8_MAX) {
+ pci_err(pdev, "Setup fail: Invalid Stream ID: %d\n", ide->stream_id);
+ return -ENXIO;
+ }
+
+ ep_stream = ide->partner[PCI_IDE_EP].stream_index;
+ rp_stream = ide->partner[PCI_IDE_RP].stream_index;
+ const char *name __free(kfree) = kasprintf(GFP_KERNEL, "stream%d.%d.%d",
+ ide->host_bridge_stream,
+ rp_stream, ep_stream);
+ if (!name)
+ return -ENOMEM;
+
+ rc = sysfs_create_link(&hb->dev.kobj, &pdev->dev.kobj, name);
+ if (rc)
+ return rc;
+
+ ide->name = no_free_ptr(name);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pci_ide_stream_register);
+
+/**
+ * pci_ide_stream_unregister() - unwind pci_ide_stream_register()
+ * @ide: idle IDE settings descriptor
+ *
+ * In preparation for freeing @ide, remove sysfs enumeration for the
+ * stream.
+ */
+void pci_ide_stream_unregister(struct pci_ide *ide)
+{
+ struct pci_dev *pdev = ide->pdev;
+ struct pci_host_bridge *hb = pci_find_host_bridge(pdev->bus);
+
+ sysfs_remove_link(&hb->dev.kobj, ide->name);
+ kfree(ide->name);
+ ide->name = NULL;
+}
+EXPORT_SYMBOL_GPL(pci_ide_stream_unregister);
+
+static int pci_ide_domain(struct pci_dev *pdev)
+{
+ if (pdev->fm_enabled)
+ return pci_domain_nr(pdev->bus);
+ return 0;
+}
+
+struct pci_ide_partner *pci_ide_to_settings(struct pci_dev *pdev, struct pci_ide *ide)
+{
+ if (!pci_is_pcie(pdev)) {
+ pci_warn_once(pdev, "not a PCIe device\n");
+ return NULL;
+ }
+
+ switch (pci_pcie_type(pdev)) {
+ case PCI_EXP_TYPE_ENDPOINT:
+ if (pdev != ide->pdev) {
+ pci_warn_once(pdev, "setup expected Endpoint: %s\n", pci_name(ide->pdev));
+ return NULL;
+ }
+ return &ide->partner[PCI_IDE_EP];
+ case PCI_EXP_TYPE_ROOT_PORT: {
+ struct pci_dev *rp = pcie_find_root_port(ide->pdev);
+
+ if (pdev != rp) {
+ pci_warn_once(pdev, "setup expected Root Port: %s\n",
+ pci_name(rp));
+ return NULL;
+ }
+ return &ide->partner[PCI_IDE_RP];
+ }
+ default:
+ pci_warn_once(pdev, "invalid device type\n");
+ return NULL;
+ }
+}
+EXPORT_SYMBOL_GPL(pci_ide_to_settings);
+
+static void set_ide_sel_ctl(struct pci_dev *pdev, struct pci_ide *ide,
+ struct pci_ide_partner *settings, int pos,
+ bool enable)
+{
+ u32 val = FIELD_PREP(PCI_IDE_SEL_CTL_ID, ide->stream_id) |
+ FIELD_PREP(PCI_IDE_SEL_CTL_DEFAULT, settings->default_stream) |
+ FIELD_PREP(PCI_IDE_SEL_CTL_CFG_EN, pdev->ide_cfg) |
+ FIELD_PREP(PCI_IDE_SEL_CTL_TEE_LIMITED, pdev->ide_tee_limit) |
+ FIELD_PREP(PCI_IDE_SEL_CTL_EN, enable);
+
+ pci_write_config_dword(pdev, pos + PCI_IDE_SEL_CTL, val);
+}
+
+/**
+ * pci_ide_stream_setup() - program settings to Selective IDE Stream registers
+ * @pdev: PCIe device object for either a Root Port or Endpoint Partner Port
+ * @ide: registered IDE settings descriptor
+ *
+ * When @pdev is a PCI_EXP_TYPE_ENDPOINT then the PCI_IDE_EP partner
+ * settings are written to @pdev's Selective IDE Stream register block,
+ * and when @pdev is a PCI_EXP_TYPE_ROOT_PORT, the PCI_IDE_RP settings
+ * are selected.
+ */
+void pci_ide_stream_setup(struct pci_dev *pdev, struct pci_ide *ide)
+{
+ struct pci_ide_partner *settings = pci_ide_to_settings(pdev, ide);
+ int pos;
+ u32 val;
+
+ if (!settings)
+ return;
+
+ pos = sel_ide_offset(pdev, settings);
+
+ val = FIELD_PREP(PCI_IDE_SEL_RID_1_LIMIT, settings->rid_end);
+ pci_write_config_dword(pdev, pos + PCI_IDE_SEL_RID_1, val);
+
+ val = FIELD_PREP(PCI_IDE_SEL_RID_2_VALID, 1) |
+ FIELD_PREP(PCI_IDE_SEL_RID_2_BASE, settings->rid_start) |
+ FIELD_PREP(PCI_IDE_SEL_RID_2_SEG, pci_ide_domain(pdev));
+
+ pci_write_config_dword(pdev, pos + PCI_IDE_SEL_RID_2, val);
+
+ /*
+ * Setup control register early for devices that expect
+ * stream_id is set during key programming.
+ */
+ set_ide_sel_ctl(pdev, ide, settings, pos, false);
+ settings->setup = 1;
+}
+EXPORT_SYMBOL_GPL(pci_ide_stream_setup);
+
+/**
+ * pci_ide_stream_teardown() - disable the stream and clear all settings
+ * @pdev: PCIe device object for either a Root Port or Endpoint Partner Port
+ * @ide: registered IDE settings descriptor
+ *
+ * For stream destruction, zero all registers that may have been written
+ * by pci_ide_stream_setup(). Consider pci_ide_stream_disable() to leave
+ * settings in place while temporarily disabling the stream.
+ */
+void pci_ide_stream_teardown(struct pci_dev *pdev, struct pci_ide *ide)
+{
+ struct pci_ide_partner *settings = pci_ide_to_settings(pdev, ide);
+ int pos;
+
+ if (!settings)
+ return;
+
+ pos = sel_ide_offset(pdev, settings);
+
+ pci_write_config_dword(pdev, pos + PCI_IDE_SEL_CTL, 0);
+ pci_write_config_dword(pdev, pos + PCI_IDE_SEL_RID_2, 0);
+ pci_write_config_dword(pdev, pos + PCI_IDE_SEL_RID_1, 0);
+ settings->setup = 0;
+}
+EXPORT_SYMBOL_GPL(pci_ide_stream_teardown);
+
+/**
+ * pci_ide_stream_enable() - enable a Selective IDE Stream
+ * @pdev: PCIe device object for either a Root Port or Endpoint Partner Port
+ * @ide: registered and setup IDE settings descriptor
+ *
+ * Activate the stream by writing to the Selective IDE Stream Control
+ * Register.
+ *
+ * Return: 0 if the stream successfully entered the "secure" state, and -EINVAL
+ * if @ide is invalid, and -ENXIO if the stream fails to enter the secure state.
+ *
+ * Note that the state may go "insecure" at any point after returning 0, but
+ * those events are equivalent to a "link down" event and handled via
+ * asynchronous error reporting.
+ *
+ * Caller is responsible to clear the enable bit in the -ENXIO case.
+ */
+int pci_ide_stream_enable(struct pci_dev *pdev, struct pci_ide *ide)
+{
+ struct pci_ide_partner *settings = pci_ide_to_settings(pdev, ide);
+ int pos;
+ u32 val;
+
+ if (!settings)
+ return -EINVAL;
+
+ pos = sel_ide_offset(pdev, settings);
+
+ set_ide_sel_ctl(pdev, ide, settings, pos, true);
+ settings->enable = 1;
+
+ pci_read_config_dword(pdev, pos + PCI_IDE_SEL_STS, &val);
+ if (FIELD_GET(PCI_IDE_SEL_STS_STATE, val) !=
+ PCI_IDE_SEL_STS_STATE_SECURE)
+ return -ENXIO;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pci_ide_stream_enable);
+
+/**
+ * pci_ide_stream_disable() - disable a Selective IDE Stream
+ * @pdev: PCIe device object for either a Root Port or Endpoint Partner Port
+ * @ide: registered and setup IDE settings descriptor
+ *
+ * Clear the Selective IDE Stream Control Register, but leave all other
+ * registers untouched.
+ */
+void pci_ide_stream_disable(struct pci_dev *pdev, struct pci_ide *ide)
+{
+ struct pci_ide_partner *settings = pci_ide_to_settings(pdev, ide);
+ int pos;
+
+ if (!settings)
+ return;
+
+ pos = sel_ide_offset(pdev, settings);
+
+ pci_write_config_dword(pdev, pos + PCI_IDE_SEL_CTL, 0);
+ settings->enable = 0;
+}
+EXPORT_SYMBOL_GPL(pci_ide_stream_disable);
+
+void pci_ide_init_host_bridge(struct pci_host_bridge *hb)
+{
+ hb->nr_ide_streams = 256;
+ ida_init(&hb->ide_stream_ida);
+}
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 3b54f1720be5..93fa7ba8dfa6 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -672,6 +672,7 @@ static void pci_init_host_bridge(struct pci_host_bridge *bridge)
bridge->native_dpc = 1;
bridge->domain_nr = PCI_DOMAIN_NR_NOT_SET;
bridge->native_cxl_error = 1;
+ pci_ide_init_host_bridge(bridge);

device_initialize(&bridge->dev);
}
--
2.51.0