Commit 62e8b17f authored by Lukas Wunner's avatar Lukas Wunner Committed by Dan Williams
Browse files

PCI/DOE: Provide synchronous API and use it internally 



The DOE API only allows asynchronous exchanges and forces callers to
provide a completion callback.  Yet all existing callers only perform
synchronous exchanges.  Upcoming commits for CMA (Component Measurement
and Authentication, PCIe r6.0 sec 6.31) likewise require only
synchronous DOE exchanges.

Provide a synchronous pci_doe() API call which builds on the internal
asynchronous machinery.

Convert the internal pci_doe_discovery() to the new call.

The new API allows submission of const-declared requests, necessitating
the addition of a const qualifier in struct pci_doe_task.

Tested-by: default avatarIra Weiny <ira.weiny@intel.com>
Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
Reviewed-by: default avatarMing Li <ming4.li@intel.com>
Reviewed-by: default avatarIra Weiny <ira.weiny@intel.com>
Reviewed-by: default avatarDavidlohr Bueso <dave@stgolabs.net>
Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/0f444206da9615c56301fbaff459c0f45d27f122.1678543498.git.lukas@wunner.de


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 09a9639e

drivers/pci/doe.c

+54 −15
Original line number Diff line number Diff line
@@ -321,26 +321,15 @@ static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 *index, u16 *vid, 
	__le32 request_pl_le = cpu_to_le32(request_pl);

	__le32 response_pl_le;

	u32 response_pl;

	DECLARE_COMPLETION_ONSTACK(c);

	struct pci_doe_task task = {

		.prot.vid = PCI_VENDOR_ID_PCI_SIG,

		.prot.type = PCI_DOE_PROTOCOL_DISCOVERY,

		.request_pl = &request_pl_le,

		.request_pl_sz = sizeof(request_pl),

		.response_pl = &response_pl_le,

		.response_pl_sz = sizeof(response_pl),

		.complete = pci_doe_task_complete,

		.private = &c,

	};

	int rc;



	rc = pci_doe_submit_task(doe_mb, &task);

	rc = pci_doe(doe_mb, PCI_VENDOR_ID_PCI_SIG, PCI_DOE_PROTOCOL_DISCOVERY,

		     &request_pl_le, sizeof(request_pl_le),

		     &response_pl_le, sizeof(response_pl_le));

	if (rc < 0)

		return rc;



	wait_for_completion(&c);



	if (task.rv != sizeof(response_pl))

	if (rc != sizeof(response_pl_le))

		return -EIO;



	response_pl = le32_to_cpu(response_pl_le);
@@ -552,3 +541,53 @@ int pci_doe_submit_task(struct pci_doe_mb *doe_mb, struct pci_doe_task *task) 
	return 0;

}

EXPORT_SYMBOL_GPL(pci_doe_submit_task);



/**

 * pci_doe() - Perform Data Object Exchange

 *

 * @doe_mb: DOE Mailbox

 * @vendor: Vendor ID

 * @type: Data Object Type

 * @request: Request payload

 * @request_sz: Size of request payload (bytes)

 * @response: Response payload

 * @response_sz: Size of response payload (bytes)

 *

 * Submit @request to @doe_mb and store the @response.

 * The DOE exchange is performed synchronously and may therefore sleep.

 *

 * Payloads are treated as opaque byte streams which are transmitted verbatim,

 * without byte-swapping.  If payloads contain little-endian register values,

 * the caller is responsible for conversion with cpu_to_le32() / le32_to_cpu().

 *

 * RETURNS: Length of received response or negative errno.

 * Received data in excess of @response_sz is discarded.

 * The length may be smaller than @response_sz and the caller

 * is responsible for checking that.

 */

int pci_doe(struct pci_doe_mb *doe_mb, u16 vendor, u8 type,

	    const void *request, size_t request_sz,

	    void *response, size_t response_sz)

{

	DECLARE_COMPLETION_ONSTACK(c);

	struct pci_doe_task task = {

		.prot.vid = vendor,

		.prot.type = type,

		.request_pl = request,

		.request_pl_sz = request_sz,

		.response_pl = response,

		.response_pl_sz = response_sz,

		.complete = pci_doe_task_complete,

		.private = &c,

	};

	int rc;



	rc = pci_doe_submit_task(doe_mb, &task);

	if (rc)

		return rc;



	wait_for_completion(&c);



	return task.rv;

}

EXPORT_SYMBOL_GPL(pci_doe);

include/linux/pci-doe.h

+5 −1
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ struct pci_doe_mb; 
 */

struct pci_doe_task {

	struct pci_doe_protocol prot;

	__le32 *request_pl;

	const __le32 *request_pl;

	size_t request_pl_sz;

	__le32 *response_pl;

	size_t response_pl_sz;
@@ -78,4 +78,8 @@ struct pci_doe_mb *pcim_doe_create_mb(struct pci_dev *pdev, u16 cap_offset); 
bool pci_doe_supports_prot(struct pci_doe_mb *doe_mb, u16 vid, u8 type);

int pci_doe_submit_task(struct pci_doe_mb *doe_mb, struct pci_doe_task *task);



int pci_doe(struct pci_doe_mb *doe_mb, u16 vendor, u8 type,

	    const void *request, size_t request_sz,

	    void *response, size_t response_sz);



#endif