PCI/DOE: Make asynchronous API private

A synchronous API for DOE has just been introduced.  CXL (the only
in-tree DOE user so far) was converted to use it instead of the
asynchronous API.

Consequently, pci_doe_submit_task() as well as the pci_doe_task struct
are only used internally, so make them private.

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: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/cc19544068483681e91dfe27545c2180cd09f931.1678543498.git.lukas@wunner.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/pci/doe.c

@@ -56,6 +56,47 @@ struct pci_doe_mb {
 	unsigned long flags;
 };
 
+struct pci_doe_protocol {
+	u16 vid;
+	u8 type;
+};
+
+/**
+ * struct pci_doe_task - represents a single query/response
+ *
+ * @prot: DOE Protocol
+ * @request_pl: The request payload
+ * @request_pl_sz: Size of the request payload (bytes)
+ * @response_pl: The response payload
+ * @response_pl_sz: Size of the response payload (bytes)
+ * @rv: Return value.  Length of received response or error (bytes)
+ * @complete: Called when task is complete
+ * @private: Private data for the consumer
+ * @work: Used internally by the mailbox
+ * @doe_mb: Used internally by the mailbox
+ *
+ * The payload sizes and rv are specified in bytes with the following
+ * restrictions concerning the protocol.
+ *
+ *	1) The request_pl_sz must be a multiple of double words (4 bytes)
+ *	2) The response_pl_sz must be >= a single double word (4 bytes)
+ *	3) rv is returned as bytes but it will be a multiple of double words
+ */
+struct pci_doe_task {
+	struct pci_doe_protocol prot;
+	const __le32 *request_pl;
+	size_t request_pl_sz;
+	__le32 *response_pl;
+	size_t response_pl_sz;
+	int rv;
+	void (*complete)(struct pci_doe_task *task);
+	void *private;
+
+	/* initialized by pci_doe_submit_task() */
+	struct work_struct work;
+	struct pci_doe_mb *doe_mb;
+};
+
 static int pci_doe_wait(struct pci_doe_mb *doe_mb, unsigned long timeout)
 {
 	if (wait_event_timeout(doe_mb->wq,
@@ -519,7 +560,8 @@ EXPORT_SYMBOL_GPL(pci_doe_supports_prot);
  *
  * RETURNS: 0 when task has been successfully queued, -ERRNO on error
  */
-int pci_doe_submit_task(struct pci_doe_mb *doe_mb, struct pci_doe_task *task)
+static int pci_doe_submit_task(struct pci_doe_mb *doe_mb,
+			       struct pci_doe_task *task)
 {
 	if (!pci_doe_supports_prot(doe_mb, task->prot.vid, task->prot.type))
 		return -EINVAL;
@@ -540,7 +582,6 @@ int pci_doe_submit_task(struct pci_doe_mb *doe_mb, struct pci_doe_task *task)
 	queue_work(doe_mb->work_queue, &task->work);
 	return 0;
 }
-EXPORT_SYMBOL_GPL(pci_doe_submit_task);
 
 /**
  * pci_doe() - Perform Data Object Exchange

include/linux/pci-doe.h

@@ -13,55 +13,8 @@
 #ifndef LINUX_PCI_DOE_H
 #define LINUX_PCI_DOE_H
 
-struct pci_doe_protocol {
-	u16 vid;
-	u8 type;
-};
-
 struct pci_doe_mb;
 
-/**
- * struct pci_doe_task - represents a single query/response
- *
- * @prot: DOE Protocol
- * @request_pl: The request payload
- * @request_pl_sz: Size of the request payload (bytes)
- * @response_pl: The response payload
- * @response_pl_sz: Size of the response payload (bytes)
- * @rv: Return value.  Length of received response or error (bytes)
- * @complete: Called when task is complete
- * @private: Private data for the consumer
- * @work: Used internally by the mailbox
- * @doe_mb: Used internally by the mailbox
- *
- * 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().
- *
- * The payload sizes and rv are specified in bytes with the following
- * restrictions concerning the protocol.
- *
- *	1) The request_pl_sz must be a multiple of double words (4 bytes)
- *	2) The response_pl_sz must be >= a single double word (4 bytes)
- *	3) rv is returned as bytes but it will be a multiple of double words
- *
- * NOTE there is no need for the caller to initialize work or doe_mb.
- */
-struct pci_doe_task {
-	struct pci_doe_protocol prot;
-	const __le32 *request_pl;
-	size_t request_pl_sz;
-	__le32 *response_pl;
-	size_t response_pl_sz;
-	int rv;
-	void (*complete)(struct pci_doe_task *task);
-	void *private;
-
-	/* No need for the user to initialize these fields */
-	struct work_struct work;
-	struct pci_doe_mb *doe_mb;
-};
-
 /**
  * pci_doe_for_each_off - Iterate each DOE capability
  * @pdev: struct pci_dev to iterate
@@ -76,7 +29,6 @@ struct pci_doe_task {
 
 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,