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@xxxxxxxxx>
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
Reviewed-by: Ming Li <ming4.li@xxxxxxxxx>
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Reviewed-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
drivers/pci/doe.c | 69 ++++++++++++++++++++++++++++++++---------
include/linux/pci-doe.h | 6 +++-
2 files changed, 59 insertions(+), 16 deletions(-)
diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c
index e5e9b287b976..adde8c66499c 100644
--- a/drivers/pci/doe.c
+++ b/drivers/pci/doe.c
@@ -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);
diff --git a/include/linux/pci-doe.h b/include/linux/pci-doe.h
index 43765eaf2342..5dcd54f892e5 100644
--- a/include/linux/pci-doe.h
+++ b/include/linux/pci-doe.h
@@ -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
--
2.39.1
