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PCI/DOE: Provide synchronous API and use it internally

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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: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Ming Li <ming4.li@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/0f444206da9615c56301fbaff459c0f45d27f122.1678543498.git.lukas@wunner.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Lukas Wunner 2023-03-11 15:40:07 +01:00 committed by Dan Williams
parent 09a9639e56
commit 62e8b17ffc
2 changed files with 59 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
drivers/pci/doe.c
View File

@ -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);

6
include/linux/pci-doe.h
View File

@ -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