Re: [PATCH v7 9/9] PCI/TSM: Report active IDE streams

Alexey Kardashevskiy
2025-10-30T02:05:45Z

On 24/10/25 13:04, Dan Williams wrote:
> Given that the platform TSM owns IDE Stream ID allocation, report the
> active streams via the TSM class device. Establish a symlink from the
> class device to the PCI endpoint device consuming the stream, named by
> the Stream ID.
>
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Reviewed-by: Alexey Kardashevskiy <aik@amd.com>

> ---
> Documentation/ABI/testing/sysfs-class-tsm | 10 ++++++++
> include/linux/pci-ide.h | 2 ++
> include/linux/tsm.h | 3 +++
> drivers/pci/ide.c | 4 ++++
> drivers/virt/coco/tsm-core.c | 29 +++++++++++++++++++++++
> 5 files changed, 48 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-class-tsm b/Documentation/ABI/testing/sysfs-class-tsm
> index 2949468deaf7..6fc1a5ac6da1 100644
> --- a/Documentation/ABI/testing/sysfs-class-tsm
> +++ b/Documentation/ABI/testing/sysfs-class-tsm
> @@ -7,3 +7,13 @@ Description:
> signals when the PCI layer is able to support establishment of
> link encryption and other device-security features coordinated
> through a platform tsm.
> +
> +What: /sys/class/tsm/tsmN/streamH.R.E
> +Contact: linux-pci@vger.kernel.org
> +Description:
> + (RO) When a host bridge has established a secure connection via
> + the platform TSM, symlink appears. The primary function of this
> + is have a system global review of TSM resource consumption
> + across host bridges. The link points to the endpoint PCI device
> + and matches the same link published by the host bridge. See
> + Documentation/ABI/testing/sysfs-devices-pci-host-bridge.
> diff --git a/include/linux/pci-ide.h b/include/linux/pci-ide.h
> index 85645b0a8620..d0f10f3c89fc 100644
> --- a/include/linux/pci-ide.h
> +++ b/include/linux/pci-ide.h
> @@ -50,6 +50,7 @@ struct pci_ide_partner {
> * @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
> + * @tsm_dev: For TSM established IDE, the TSM device context
> *
> * Negative @stream_id values indicate "uninitialized" on the
> * expectation that with TSM established IDE the TSM owns the stream_id
> @@ -61,6 +62,7 @@ struct pci_ide {
> u8 host_bridge_stream;
> int stream_id;
> const char *name;
> + struct tsm_dev *tsm_dev;
> };
>
> void pci_ide_set_nr_streams(struct pci_host_bridge *hb, u16 nr);
> diff --git a/include/linux/tsm.h b/include/linux/tsm.h
> index ee9a54ae3d3c..376139585797 100644
> --- a/include/linux/tsm.h
> +++ b/include/linux/tsm.h
> @@ -120,4 +120,7 @@ int tsm_report_unregister(const struct tsm_report_ops *ops);
> struct tsm_dev *tsm_register(struct device *parent, struct pci_tsm_ops *ops);
> void tsm_unregister(struct tsm_dev *tsm_dev);
> struct tsm_dev *find_tsm_dev(int id);
> +struct pci_ide;
> +int tsm_ide_stream_register(struct pci_ide *ide);
> +void tsm_ide_stream_unregister(struct pci_ide *ide);
> #endif /* __TSM_H */
> diff --git a/drivers/pci/ide.c b/drivers/pci/ide.c
> index 44f62da5e191..5659f988e524 100644
> --- a/drivers/pci/ide.c
> +++ b/drivers/pci/ide.c
> @@ -11,6 +11,7 @@
> #include <linux/pci_regs.h>
> #include <linux/slab.h>
> #include <linux/sysfs.h>
> +#include <linux/tsm.h>
>
> #include "pci.h"
>
> @@ -264,6 +265,9 @@ void pci_ide_stream_release(struct pci_ide *ide)
> if (ide->partner[PCI_IDE_EP].enable)
> pci_ide_stream_disable(pdev, ide);
>
> + if (ide->tsm_dev)
> + tsm_ide_stream_unregister(ide);
> +
> if (ide->partner[PCI_IDE_RP].setup)
> pci_ide_stream_teardown(rp, ide);
>
> diff --git a/drivers/virt/coco/tsm-core.c b/drivers/virt/coco/tsm-core.c
> index 4499803cf20d..c0dae531b64f 100644
> --- a/drivers/virt/coco/tsm-core.c
> +++ b/drivers/virt/coco/tsm-core.c
> @@ -2,14 +2,17 @@
> /* Copyright(c) 2024 Intel Corporation. All rights reserved. */
>
> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +#define dev_fmt(fmt) KBUILD_MODNAME ": " fmt
>
> #include <linux/tsm.h>
> #include <linux/idr.h>
> +#include <linux/pci.h>
> #include <linux/rwsem.h>
> #include <linux/device.h>
> #include <linux/module.h>
> #include <linux/cleanup.h>
> #include <linux/pci-tsm.h>
> +#include <linux/pci-ide.h>
>
> static struct class *tsm_class;
> static DECLARE_RWSEM(tsm_rwsem);
> @@ -106,6 +109,32 @@ void tsm_unregister(struct tsm_dev *tsm_dev)
> }
> EXPORT_SYMBOL_GPL(tsm_unregister);
>
> +/* must be invoked between tsm_register / tsm_unregister */
> +int tsm_ide_stream_register(struct pci_ide *ide)
> +{
> + struct pci_dev *pdev = ide->pdev;
> + struct pci_tsm *tsm = pdev->tsm;
> + struct tsm_dev *tsm_dev = tsm->tsm_dev;
> + int rc;
> +
> + rc = sysfs_create_link(&tsm_dev->dev.kobj, &pdev->dev.kobj, ide->name);
> + if (rc)
> + return rc;
> +
> + ide->tsm_dev = tsm_dev;
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(tsm_ide_stream_register);
> +
> +void tsm_ide_stream_unregister(struct pci_ide *ide)
> +{
> + struct tsm_dev *tsm_dev = ide->tsm_dev;
> +
> + sysfs_remove_link(&tsm_dev->dev.kobj, ide->name);
> + ide->tsm_dev = NULL;
> +}
> +EXPORT_SYMBOL_GPL(tsm_ide_stream_unregister);
> +
> static void tsm_release(struct device *dev)
> {
> struct tsm_dev *tsm_dev = container_of(dev, typeof(*tsm_dev), dev);

--
Alexey