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authorLukas Wunner <lukas@wunner.de>2023-03-11 17:40:07 +0300
committerDan Williams <dan.j.williams@intel.com>2023-04-18 20:36:58 +0300
commit62e8b17ffc2ff0b0e29d5e05a18570c3e70b35ff (patch)
treed7e45d3d3e40d4a8fa2789048ad7d505861ab898 /drivers/pci
parent09a9639e56c01c7a00d6c0ca63f4c7c41abe075d (diff)
downloadlinux-62e8b17ffc2ff0b0e29d5e05a18570c3e70b35ff.tar.xz
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: 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>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/doe.c69
1 files changed, 54 insertions, 15 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);