[PATCH RFC 20/39] mmc: core: Add support for handling CQE requests

Adrian Hunter
2017-02-10T13:12:20Z

Add core support for handling CQE requests, including starting, completing
and recovering.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
drivers/mmc/core/core.c | 147 +++++++++++++++++++++++++++++++++++++++++++++--
include/linux/mmc/core.h | 6 ++
2 files changed, 148 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 916bae093929..2eda589db53d 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -265,7 +265,8 @@ static void __mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
host->ops->request(host, mrq);
}

-static void mmc_mrq_pr_debug(struct mmc_host *host, struct mmc_request *mrq)
+static void mmc_mrq_pr_debug(struct mmc_host *host, struct mmc_request *mrq,
+ bool cqe)
{
if (mrq->sbc) {
pr_debug("<%s: starting CMD%u arg %08x flags %08x>\n",
@@ -274,9 +275,12 @@ static void mmc_mrq_pr_debug(struct mmc_host *host, struct mmc_request *mrq)
}

if (mrq->cmd) {
- pr_debug("%s: starting CMD%u arg %08x flags %08x\n",
- mmc_hostname(host), mrq->cmd->opcode, mrq->cmd->arg,
- mrq->cmd->flags);
+ pr_debug("%s: starting %sCMD%u arg %08x flags %08x\n",
+ mmc_hostname(host), cqe ? "CQE direct " : "",
+ mrq->cmd->opcode, mrq->cmd->arg, mrq->cmd->flags);
+ } else if (cqe) {
+ pr_debug("%s: starting CQE transfer for tag %d blkaddr %u\n",
+ mmc_hostname(host), mrq->tag, mrq->data->blk_addr);
}

if (mrq->data) {
@@ -344,7 +348,7 @@ static int mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
if (mmc_card_removed(host->card))
return -ENOMEDIUM;

- mmc_mrq_pr_debug(host, mrq);
+ mmc_mrq_pr_debug(host, mrq, false);

WARN_ON(!host->claimed);

@@ -358,6 +362,139 @@ static int mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
return 0;
}

+int mmc_cqe_start_req(struct mmc_host *host, struct mmc_request *mrq)
+{
+ int err;
+
+ /* Caller must hold retuning while CQE is in use */
+ err = mmc_retune(host);
+ if (err)
+ goto out_err;
+
+ mrq->host = host;
+
+ mmc_mrq_pr_debug(host, mrq, true);
+
+ err = mmc_mrq_prep(host, mrq);
+ if (err)
+ goto out_err;
+
+ err = host->cqe_ops->cqe_request(host, mrq);
+ if (err)
+ goto out_err;
+
+ trace_mmc_request_start(host, mrq);
+
+ return 0;
+
+out_err:
+ if (mrq->cmd) {
+ pr_debug("%s: failed to start CQE direct CMD%u, error %d\n",
+ mmc_hostname(host), mrq->cmd->opcode, err);
+ } else {
+ pr_debug("%s: failed to start CQE transfer for tag %d, error %d\n",
+ mmc_hostname(host), mrq->tag, err);
+ }
+ return err;
+}
+EXPORT_SYMBOL(mmc_cqe_start_req);
+
+void __mmc_cqe_request_done(struct mmc_host *host, struct mmc_request *mrq)
+{
+ mmc_should_fail_request(host, mrq);
+
+ /* Flag re-tuning needed on CRC errors */
+ if ((mrq->cmd && mrq->cmd->error == -EILSEQ) ||
+ (mrq->data && mrq->data->error == -EILSEQ))
+ mmc_retune_needed(host);
+
+ trace_mmc_request_done(host, mrq);
+
+ if (mrq->cmd) {
+ pr_debug("%s: CQE req done (direct CMD%u): %d\n",
+ mmc_hostname(host), mrq->cmd->opcode, mrq->cmd->error);
+ } else {
+ pr_debug("%s: CQE transfer done tag %d\n",
+ mmc_hostname(host), mrq->tag);
+ }
+
+ if (mrq->data) {
+ pr_debug("%s: %d bytes transferred: %d\n",
+ mmc_hostname(host),
+ mrq->data->bytes_xfered, mrq->data->error);
+ }
+}
+EXPORT_SYMBOL(__mmc_cqe_request_done);
+
+/**
+ * mmc_cqe_request_done - CQE has finished processing an MMC request
+ * @host: MMC host which completed request
+ * @mrq: MMC request which completed
+ *
+ * CQE drivers should call this function when they have completed
+ * their processing of a request.
+ */
+void mmc_cqe_request_done(struct mmc_host *host, struct mmc_request *mrq)
+{
+ __mmc_cqe_request_done(host, mrq);
+
+ mrq->done(mrq);
+}
+EXPORT_SYMBOL(mmc_cqe_request_done);
+
+/**
+ * mmc_cqe_post_req - CQE post process of a completed MMC request
+ * @host: MMC host
+ * @mrq: MMC request to be processed
+ */
+void mmc_cqe_post_req(struct mmc_host *host, struct mmc_request *mrq)
+{
+ if (host->cqe_ops->cqe_post_req)
+ host->cqe_ops->cqe_post_req(host, mrq);
+}
+EXPORT_SYMBOL(mmc_cqe_post_req);
+
+/* Arbitrary 1 second timeout */
+#define MMC_CQE_RECOVERY_TIMEOUT 1000
+
+int mmc_cqe_recovery(struct mmc_host *host, bool forget_reqs)
+{
+ struct mmc_command cmd;
+ int err;
+
+ mmc_retune_hold_now(host);
+
+ /*
+ * Recovery is expected seldom, if at all, but it reduces performance,
+ * so make sure it is not completely silent.
+ */
+ pr_warn("%s: running CQE recovery\n", mmc_hostname(host));
+
+ host->cqe_ops->cqe_recovery_start(host);
+
+ memset(&cmd, 0, sizeof(cmd));
+ cmd.opcode = MMC_STOP_TRANSMISSION,
+ cmd.flags = MMC_RSP_R1B | MMC_CMD_AC,
+ cmd.flags &= ~MMC_RSP_CRC; /* Ignore CRC */
+ cmd.busy_timeout = MMC_CQE_RECOVERY_TIMEOUT,
+ mmc_wait_for_cmd(host, &cmd, 0);
+
+ memset(&cmd, 0, sizeof(cmd));
+ cmd.opcode = MMC_CMDQ_TASK_MGMT;
+ cmd.arg = 1; /* Discard entire queue */
+ cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
+ cmd.flags &= ~MMC_RSP_CRC; /* Ignore CRC */
+ cmd.busy_timeout = MMC_CQE_RECOVERY_TIMEOUT,
+ err = mmc_wait_for_cmd(host, &cmd, 0);
+
+ host->cqe_ops->cqe_recovery_finish(host, forget_reqs);
+
+ mmc_retune_release(host);
+
+ return err;
+}
+EXPORT_SYMBOL(mmc_cqe_recovery);
+
/**
* mmc_start_bkops - start BKOPS for supported cards
* @card: MMC card to start BKOPS
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index da82a6dbe9fb..4f7848ba2f04 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -175,6 +175,12 @@ struct mmc_async_req *mmc_start_areq(struct mmc_host *host,
int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd,
int retries);

+int mmc_cqe_start_req(struct mmc_host *host, struct mmc_request *mrq);
+void __mmc_cqe_request_done(struct mmc_host *host, struct mmc_request *mrq);
+void mmc_cqe_request_done(struct mmc_host *host, struct mmc_request *mrq);
+void mmc_cqe_post_req(struct mmc_host *host, struct mmc_request *mrq);
+int mmc_cqe_recovery(struct mmc_host *host, bool forget_reqs);
+
int mmc_hw_reset(struct mmc_host *host);
void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card);

--
1.9.1