Commit a4438f06 authored by Dan Williams's avatar Dan Williams
Browse files

PCI/TSM: Report active IDE streams 



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: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarJonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: default avatarAlexey Kardashevskiy <aik@amd.com>
Link: https://patch.msgid.link/20251031212902.2256310-10-dan.j.williams@intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 9ddaf9c3

Documentation/ABI/testing/sysfs-class-tsm

+10 −0
Original line number Diff line number Diff line
@@ -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.

drivers/pci/ide.c

+4 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/pci_regs.h>

#include <linux/slab.h>

#include <linux/sysfs.h>

#include <linux/tsm.h>



#include "pci.h"
@@ -261,6 +262,9 @@ 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);

drivers/virt/coco/tsm-core.c

+28 −0
Original line number Diff line number Diff line
@@ -4,11 +4,13 @@ 
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt



#include <linux/tsm.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 +108,32 @@ 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;



	ide->tsm_dev = NULL;

	sysfs_remove_link(&tsm_dev->dev.kobj, ide->name);

}

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);

include/linux/pci-ide.h

+2 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/tsm.h

+3 −0
Original line number Diff line number Diff line
@@ -123,4 +123,7 @@ 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 */