1 files changed, 103 insertions, 10 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index ac82865b8c2f..ab36c7b491f3 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -198,9 +198,109 @@ mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
 
 static void mmc_wait_done(struct mmc_request *mrq)
 {
-	complete(mrq->done_data);
+	complete(&mrq->completion);
 }
 
+static void __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq)
+{
+	init_completion(&mrq->completion);
+	mrq->done = mmc_wait_done;
+	mmc_start_request(host, mrq);
+}
+
+static void mmc_wait_for_req_done(struct mmc_host *host,
+				  struct mmc_request *mrq)
+{
+	wait_for_completion(&mrq->completion);
+}
+
+/**
+ *	mmc_pre_req - Prepare for a new request
+ *	@host: MMC host to prepare command
+ *	@mrq: MMC request to prepare for
+ *	@is_first_req: true if there is no previous started request
+ *                     that may run in parellel to this call, otherwise false
+ *
+ *	mmc_pre_req() is called in prior to mmc_start_req() to let
+ *	host prepare for the new request. Preparation of a request may be
+ *	performed while another request is running on the host.
+ */
+static void mmc_pre_req(struct mmc_host *host, struct mmc_request *mrq,
+		 bool is_first_req)
+{
+	if (host->ops->pre_req)
+		host->ops->pre_req(host, mrq, is_first_req);
+}
+
+/**
+ *	mmc_post_req - Post process a completed request
+ *	@host: MMC host to post process command
+ *	@mrq: MMC request to post process for
+ *	@err: Error, if non zero, clean up any resources made in pre_req
+ *
+ *	Let the host post process a completed request. Post processing of
+ *	a request may be performed while another reuqest is running.
+ */
+static void mmc_post_req(struct mmc_host *host, struct mmc_request *mrq,
+			 int err)
+{
+	if (host->ops->post_req)
+		host->ops->post_req(host, mrq, err);
+}
+
+/**
+ *	mmc_start_req - start a non-blocking request
+ *	@host: MMC host to start command
+ *	@areq: async request to start
+ *	@error: out parameter returns 0 for success, otherwise non zero
+ *
+ *	Start a new MMC custom command request for a host.
+ *	If there is on ongoing async request wait for completion
+ *	of that request and start the new one and return.
+ *	Does not wait for the new request to complete.
+ *
+ *      Returns the completed request, NULL in case of none completed.
+ *	Wait for the an ongoing request (previoulsy started) to complete and
+ *	return the completed request. If there is no ongoing request, NULL
+ *	is returned without waiting. NULL is not an error condition.
+ */
+struct mmc_async_req *mmc_start_req(struct mmc_host *host,
+				    struct mmc_async_req *areq, int *error)
+{
+	int err = 0;
+	struct mmc_async_req *data = host->areq;
+
+	/* Prepare a new request */
+	if (areq)
+		mmc_pre_req(host, areq->mrq, !host->areq);
+
+	if (host->areq) {
+		mmc_wait_for_req_done(host, host->areq->mrq);
+		err = host->areq->err_check(host->card, host->areq);
+		if (err) {
+			mmc_post_req(host, host->areq->mrq, 0);
+			if (areq)
+				mmc_post_req(host, areq->mrq, -EINVAL);
+
+			host->areq = NULL;
+			goto out;
+		}
+	}
+
+	if (areq)
+		__mmc_start_req(host, areq->mrq);
+
+	if (host->areq)
+		mmc_post_req(host, host->areq->mrq, 0);
+
+	host->areq = areq;
+ out:
+	if (error)
+		*error = err;
+	return data;
+}
+EXPORT_SYMBOL(mmc_start_req);
+
 /**
  *	mmc_wait_for_req - start a request and wait for completion
  *	@host: MMC host to start command
@@ -212,16 +312,9 @@ static void mmc_wait_done(struct mmc_request *mrq)
  */
 void mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq)
 {
-	DECLARE_COMPLETION_ONSTACK(complete);
-
-	mrq->done_data = &complete;
-	mrq->done = mmc_wait_done;
-
-	mmc_start_request(host, mrq);
-
-	wait_for_completion(&complete);
+	__mmc_start_req(host, mrq);
+	mmc_wait_for_req_done(host, mrq);
 }
-
 EXPORT_SYMBOL(mmc_wait_for_req);
 
 /**