mmc: sdhci: Call mmc_request_done() from IRQ handler if possible

In preparation for removing finish_tasklet, call mmc_request_done() from
the IRQ handler if possible. That will alleviate the potential loss of
performance from shifting away from finish_tasklet.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Faiz Abbas <faiz_abbas@ti.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci.c

@@ -1332,14 +1332,14 @@ static void sdhci_finish_data(struct sdhci_host *host)
 		 * responsibility to send the stop command if required.
 		 */
 		if (data->mrq->cap_cmd_during_tfr) {
-			sdhci_finish_mrq(host, data->mrq);
+			__sdhci_finish_mrq(host, data->mrq);
 		} else {
 			/* Avoid triggering warning in sdhci_send_command() */
 			host->cmd = NULL;
 			sdhci_send_command(host, data->stop);
 		}
 	} else {
-		sdhci_finish_mrq(host, data->mrq);
+		__sdhci_finish_mrq(host, data->mrq);
 	}
 }
 
@@ -1502,7 +1502,7 @@ static void sdhci_finish_command(struct sdhci_host *host)
 			sdhci_finish_data(host);
 
 		if (!cmd->data)
-			sdhci_finish_mrq(host, cmd->mrq);
+			__sdhci_finish_mrq(host, cmd->mrq);
 	}
 }
 
@@ -2761,6 +2761,7 @@ static void sdhci_timeout_data_timer(struct timer_list *t)
 		if (host->data) {
 			host->data->error = -ETIMEDOUT;
 			sdhci_finish_data(host);
+			tasklet_schedule(&host->finish_tasklet);
 		} else if (host->data_cmd) {
 			host->data_cmd->error = -ETIMEDOUT;
 			sdhci_finish_mrq(host, host->data_cmd->mrq);
@@ -2827,7 +2828,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *intmask_p)
 			return;
 		}
 
-		sdhci_finish_mrq(host, host->cmd->mrq);
+		__sdhci_finish_mrq(host, host->cmd->mrq);
 		return;
 	}
 
@@ -2841,7 +2842,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *intmask_p)
 
 		if (mrq->sbc && (host->flags & SDHCI_AUTO_CMD23)) {
 			mrq->sbc->error = err;
-			sdhci_finish_mrq(host, mrq);
+			__sdhci_finish_mrq(host, mrq);
 			return;
 		}
 	}
@@ -2905,7 +2906,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
 				host->data_cmd = NULL;
 				data_cmd->error = -ETIMEDOUT;
-				sdhci_finish_mrq(host, data_cmd->mrq);
+				__sdhci_finish_mrq(host, data_cmd->mrq);
 				return;
 			}
 			if (intmask & SDHCI_INT_DATA_END) {
@@ -2918,7 +2919,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 				if (host->cmd == data_cmd)
 					return;
 
-				sdhci_finish_mrq(host, data_cmd->mrq);
+				__sdhci_finish_mrq(host, data_cmd->mrq);
 				return;
 			}
 		}
@@ -3001,12 +3002,24 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 	}
 }
 
+static inline bool sdhci_defer_done(struct sdhci_host *host,
+				    struct mmc_request *mrq)
+{
+	struct mmc_data *data = mrq->data;
+
+	return host->pending_reset ||
+	       ((host->flags & SDHCI_REQ_USE_DMA) && data &&
+		data->host_cookie == COOKIE_MAPPED);
+}
+
 static irqreturn_t sdhci_irq(int irq, void *dev_id)
 {
+	struct mmc_request *mrqs_done[SDHCI_MAX_MRQS] = {0};
 	irqreturn_t result = IRQ_NONE;
 	struct sdhci_host *host = dev_id;
 	u32 intmask, mask, unexpected = 0;
 	int max_loops = 16;
+	int i;
 
 	spin_lock(&host->lock);
 
@@ -3100,9 +3113,30 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
 
 		intmask = sdhci_readl(host, SDHCI_INT_STATUS);
 	} while (intmask && --max_loops);
+
+	/* Determine if mrqs can be completed immediately */
+	for (i = 0; i < SDHCI_MAX_MRQS; i++) {
+		struct mmc_request *mrq = host->mrqs_done[i];
+
+		if (!mrq)
+			continue;
+
+		if (sdhci_defer_done(host, mrq)) {
+			tasklet_schedule(&host->finish_tasklet);
+		} else {
+			mrqs_done[i] = mrq;
+			host->mrqs_done[i] = NULL;
+		}
+	}
 out:
 	spin_unlock(&host->lock);
 
+	/* Process mrqs ready for immediate completion */
+	for (i = 0; i < SDHCI_MAX_MRQS; i++) {
+		if (mrqs_done[i])
+			mmc_request_done(host->mmc, mrqs_done[i]);
+	}
+
 	if (unexpected) {
 		pr_err("%s: Unexpected interrupt 0x%08x.\n",
 			   mmc_hostname(host->mmc), unexpected);