1 files changed, 313 insertions, 84 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 1b1c26da3fe0..63db84481dff 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -10,6 +10,7 @@
  */
 
 #include <linux/delay.h>
+#include <linux/dmaengine.h>
 #include <linux/ktime.h>
 #include <linux/highmem.h>
 #include <linux/io.h>
@@ -992,7 +993,7 @@ static void sdhci_set_transfer_irqs(struct sdhci_host *host)
 	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
 }
 
-static void sdhci_set_data_timeout_irq(struct sdhci_host *host, bool enable)
+void sdhci_set_data_timeout_irq(struct sdhci_host *host, bool enable)
 {
 	if (enable)
 		host->ier |= SDHCI_INT_DATA_TIMEOUT;
@@ -1001,42 +1002,36 @@ static void sdhci_set_data_timeout_irq(struct sdhci_host *host, bool enable)
 	sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
 	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
 }
+EXPORT_SYMBOL_GPL(sdhci_set_data_timeout_irq);
 
-static void sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
+void __sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
 {
-	u8 count;
-
-	if (host->ops->set_timeout) {
-		host->ops->set_timeout(host, cmd);
-	} else {
-		bool too_big = false;
-
-		count = sdhci_calc_timeout(host, cmd, &too_big);
-
-		if (too_big &&
-		    host->quirks2 & SDHCI_QUIRK2_DISABLE_HW_TIMEOUT) {
-			sdhci_calc_sw_timeout(host, cmd);
-			sdhci_set_data_timeout_irq(host, false);
-		} else if (!(host->ier & SDHCI_INT_DATA_TIMEOUT)) {
-			sdhci_set_data_timeout_irq(host, true);
-		}
-
-		sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
+	bool too_big = false;
+	u8 count = sdhci_calc_timeout(host, cmd, &too_big);
+
+	if (too_big &&
+	    host->quirks2 & SDHCI_QUIRK2_DISABLE_HW_TIMEOUT) {
+		sdhci_calc_sw_timeout(host, cmd);
+		sdhci_set_data_timeout_irq(host, false);
+	} else if (!(host->ier & SDHCI_INT_DATA_TIMEOUT)) {
+		sdhci_set_data_timeout_irq(host, true);
 	}
+
+	sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
 }
+EXPORT_SYMBOL_GPL(__sdhci_set_timeout);
 
-static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
+static void sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
 {
-	struct mmc_data *data = cmd->data;
-
-	host->data_timeout = 0;
-
-	if (sdhci_data_line_cmd(cmd))
-		sdhci_set_timeout(host, cmd);
-
-	if (!data)
-		return;
+	if (host->ops->set_timeout)
+		host->ops->set_timeout(host, cmd);
+	else
+		__sdhci_set_timeout(host, cmd);
+}
 
+static void sdhci_initialize_data(struct sdhci_host *host,
+				  struct mmc_data *data)
+{
 	WARN_ON(host->data);
 
 	/* Sanity checks */
@@ -1047,6 +1042,34 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
 	host->data = data;
 	host->data_early = 0;
 	host->data->bytes_xfered = 0;
+}
+
+static inline void sdhci_set_block_info(struct sdhci_host *host,
+					struct mmc_data *data)
+{
+	/* Set the DMA boundary value and block size */
+	sdhci_writew(host,
+		     SDHCI_MAKE_BLKSZ(host->sdma_boundary, data->blksz),
+		     SDHCI_BLOCK_SIZE);
+	/*
+	 * For Version 4.10 onwards, if v4 mode is enabled, 32-bit Block Count
+	 * can be supported, in that case 16-bit block count register must be 0.
+	 */
+	if (host->version >= SDHCI_SPEC_410 && host->v4_mode &&
+	    (host->quirks2 & SDHCI_QUIRK2_USE_32BIT_BLK_CNT)) {
+		if (sdhci_readw(host, SDHCI_BLOCK_COUNT))
+			sdhci_writew(host, 0, SDHCI_BLOCK_COUNT);
+		sdhci_writew(host, data->blocks, SDHCI_32BIT_BLK_CNT);
+	} else {
+		sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
+	}
+}
+
+static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
+{
+	struct mmc_data *data = cmd->data;
+
+	sdhci_initialize_data(host, data);
 
 	if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
 		struct scatterlist *sg;
@@ -1133,24 +1156,192 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
 
 	sdhci_set_transfer_irqs(host);
 
-	/* Set the DMA boundary value and block size */
-	sdhci_writew(host, SDHCI_MAKE_BLKSZ(host->sdma_boundary, data->blksz),
-		     SDHCI_BLOCK_SIZE);
+	sdhci_set_block_info(host, data);
+}
 
-	/*
-	 * For Version 4.10 onwards, if v4 mode is enabled, 32-bit Block Count
-	 * can be supported, in that case 16-bit block count register must be 0.
-	 */
-	if (host->version >= SDHCI_SPEC_410 && host->v4_mode &&
-	    (host->quirks2 & SDHCI_QUIRK2_USE_32BIT_BLK_CNT)) {
-		if (sdhci_readw(host, SDHCI_BLOCK_COUNT))
-			sdhci_writew(host, 0, SDHCI_BLOCK_COUNT);
-		sdhci_writew(host, data->blocks, SDHCI_32BIT_BLK_CNT);
+#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
+
+static int sdhci_external_dma_init(struct sdhci_host *host)
+{
+	int ret = 0;
+	struct mmc_host *mmc = host->mmc;
+
+	host->tx_chan = dma_request_chan(mmc->parent, "tx");
+	if (IS_ERR(host->tx_chan)) {
+		ret = PTR_ERR(host->tx_chan);
+		if (ret != -EPROBE_DEFER)
+			pr_warn("Failed to request TX DMA channel.\n");
+		host->tx_chan = NULL;
+		return ret;
+	}
+
+	host->rx_chan = dma_request_chan(mmc->parent, "rx");
+	if (IS_ERR(host->rx_chan)) {
+		if (host->tx_chan) {
+			dma_release_channel(host->tx_chan);
+			host->tx_chan = NULL;
+		}
+
+		ret = PTR_ERR(host->rx_chan);
+		if (ret != -EPROBE_DEFER)
+			pr_warn("Failed to request RX DMA channel.\n");
+		host->rx_chan = NULL;
+	}
+
+	return ret;
+}
+
+static struct dma_chan *sdhci_external_dma_channel(struct sdhci_host *host,
+						   struct mmc_data *data)
+{
+	return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
+}
+
+static int sdhci_external_dma_setup(struct sdhci_host *host,
+				    struct mmc_command *cmd)
+{
+	int ret, i;
+	enum dma_transfer_direction dir;
+	struct dma_async_tx_descriptor *desc;
+	struct mmc_data *data = cmd->data;
+	struct dma_chan *chan;
+	struct dma_slave_config cfg;
+	dma_cookie_t cookie;
+	int sg_cnt;
+
+	if (!host->mapbase)
+		return -EINVAL;
+
+	cfg.src_addr = host->mapbase + SDHCI_BUFFER;
+	cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
+	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	cfg.src_maxburst = data->blksz / 4;
+	cfg.dst_maxburst = data->blksz / 4;
+
+	/* Sanity check: all the SG entries must be aligned by block size. */
+	for (i = 0; i < data->sg_len; i++) {
+		if ((data->sg + i)->length % data->blksz)
+			return -EINVAL;
+	}
+
+	chan = sdhci_external_dma_channel(host, data);
+
+	ret = dmaengine_slave_config(chan, &cfg);
+	if (ret)
+		return ret;
+
+	sg_cnt = sdhci_pre_dma_transfer(host, data, COOKIE_MAPPED);
+	if (sg_cnt <= 0)
+		return -EINVAL;
+
+	dir = data->flags & MMC_DATA_WRITE ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
+	desc = dmaengine_prep_slave_sg(chan, data->sg, data->sg_len, dir,
+				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc)
+		return -EINVAL;
+
+	desc->callback = NULL;
+	desc->callback_param = NULL;
+
+	cookie = dmaengine_submit(desc);
+	if (dma_submit_error(cookie))
+		ret = cookie;
+
+	return ret;
+}
+
+static void sdhci_external_dma_release(struct sdhci_host *host)
+{
+	if (host->tx_chan) {
+		dma_release_channel(host->tx_chan);
+		host->tx_chan = NULL;
+	}
+
+	if (host->rx_chan) {
+		dma_release_channel(host->rx_chan);
+		host->rx_chan = NULL;
+	}
+
+	sdhci_switch_external_dma(host, false);
+}
+
+static void __sdhci_external_dma_prepare_data(struct sdhci_host *host,
+					      struct mmc_command *cmd)
+{
+	struct mmc_data *data = cmd->data;
+
+	sdhci_initialize_data(host, data);
+
+	host->flags |= SDHCI_REQ_USE_DMA;
+	sdhci_set_transfer_irqs(host);
+
+	sdhci_set_block_info(host, data);
+}
+
+static void sdhci_external_dma_prepare_data(struct sdhci_host *host,
+					    struct mmc_command *cmd)
+{
+	if (!sdhci_external_dma_setup(host, cmd)) {
+		__sdhci_external_dma_prepare_data(host, cmd);
 	} else {
-		sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
+		sdhci_external_dma_release(host);
+		pr_err("%s: Cannot use external DMA, switch to the DMA/PIO which standard SDHCI provides.\n",
+		       mmc_hostname(host->mmc));
+		sdhci_prepare_data(host, cmd);
 	}
 }
 
+static void sdhci_external_dma_pre_transfer(struct sdhci_host *host,
+					    struct mmc_command *cmd)
+{
+	struct dma_chan *chan;
+
+	if (!cmd->data)
+		return;
+
+	chan = sdhci_external_dma_channel(host, cmd->data);
+	if (chan)
+		dma_async_issue_pending(chan);
+}
+
+#else
+
+static inline int sdhci_external_dma_init(struct sdhci_host *host)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void sdhci_external_dma_release(struct sdhci_host *host)
+{
+}
+
+static inline void sdhci_external_dma_prepare_data(struct sdhci_host *host,
+						   struct mmc_command *cmd)
+{
+	/* This should never happen */
+	WARN_ON_ONCE(1);
+}
+
+static inline void sdhci_external_dma_pre_transfer(struct sdhci_host *host,
+						   struct mmc_command *cmd)
+{
+}
+
+static inline struct dma_chan *sdhci_external_dma_channel(struct sdhci_host *host,
+							  struct mmc_data *data)
+{
+	return NULL;
+}
+
+#endif
+
+void sdhci_switch_external_dma(struct sdhci_host *host, bool en)
+{
+	host->use_external_dma = en;
+}
+EXPORT_SYMBOL_GPL(sdhci_switch_external_dma);
+
 static inline bool sdhci_auto_cmd12(struct sdhci_host *host,
 				    struct mmc_request *mrq)
 {
@@ -1245,22 +1436,10 @@ static bool sdhci_needs_reset(struct sdhci_host *host, struct mmc_request *mrq)
 		 (host->quirks & SDHCI_QUIRK_RESET_AFTER_REQUEST)));
 }
 
-static void __sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
+static void sdhci_set_mrq_done(struct sdhci_host *host, struct mmc_request *mrq)
 {
 	int i;
 
-	if (host->cmd && host->cmd->mrq == mrq)
-		host->cmd = NULL;
-
-	if (host->data_cmd && host->data_cmd->mrq == mrq)
-		host->data_cmd = NULL;
-
-	if (host->data && host->data->mrq == mrq)
-		host->data = NULL;
-
-	if (sdhci_needs_reset(host, mrq))
-		host->pending_reset = true;
-
 	for (i = 0; i < SDHCI_MAX_MRQS; i++) {
 		if (host->mrqs_done[i] == mrq) {
 			WARN_ON(1);
@@ -1276,6 +1455,23 @@ static void __sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
 	}
 
 	WARN_ON(i >= SDHCI_MAX_MRQS);
+}
+
+static void __sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
+{
+	if (host->cmd && host->cmd->mrq == mrq)
+		host->cmd = NULL;
+
+	if (host->data_cmd && host->data_cmd->mrq == mrq)
+		host->data_cmd = NULL;
+
+	if (host->data && host->data->mrq == mrq)
+		host->data = NULL;
+
+	if (sdhci_needs_reset(host, mrq))
+		host->pending_reset = true;
+
+	sdhci_set_mrq_done(host, mrq);
 
 	sdhci_del_timer(host, mrq);
 
@@ -1326,12 +1522,12 @@ static void sdhci_finish_data(struct sdhci_host *host)
 
 	/*
 	 * Need to send CMD12 if -
-	 * a) open-ended multiblock transfer (no CMD23)
+	 * a) open-ended multiblock transfer not using auto CMD12 (no CMD23)
 	 * b) error in multiblock transfer
 	 */
 	if (data->stop &&
-	    (data->error ||
-	     !data->mrq->sbc)) {
+	    ((!data->mrq->sbc && !sdhci_auto_cmd12(host, data->mrq)) ||
+	     data->error)) {
 		/*
 		 * 'cap_cmd_during_tfr' request must not use the command line
 		 * after mmc_command_done() has been called. It is upper layer's
@@ -1390,12 +1586,19 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 	}
 
 	host->cmd = cmd;
+	host->data_timeout = 0;
 	if (sdhci_data_line_cmd(cmd)) {
 		WARN_ON(host->data_cmd);
 		host->data_cmd = cmd;
+		sdhci_set_timeout(host, cmd);
 	}
 
-	sdhci_prepare_data(host, cmd);
+	if (cmd->data) {
+		if (host->use_external_dma)
+			sdhci_external_dma_prepare_data(host, cmd);
+		else
+			sdhci_prepare_data(host, cmd);
+	}
 
 	sdhci_writel(host, cmd->arg, SDHCI_ARGUMENT);
 
@@ -1437,6 +1640,9 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 		timeout += 10 * HZ;
 	sdhci_mod_timer(host, cmd->mrq, timeout);
 
+	if (host->use_external_dma)
+		sdhci_external_dma_pre_transfer(host, cmd);
+
 	sdhci_writew(host, SDHCI_MAKE_CMD(cmd->opcode, flags), SDHCI_COMMAND);
 }
 EXPORT_SYMBOL_GPL(sdhci_send_command);
@@ -1825,17 +2031,6 @@ void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 
 	sdhci_led_activate(host);
 
-	/*
-	 * Ensure we don't send the STOP for non-SET_BLOCK_COUNTED
-	 * requests if Auto-CMD12 is enabled.
-	 */
-	if (sdhci_auto_cmd12(host, mrq)) {
-		if (mrq->stop) {
-			mrq->data->stop = NULL;
-			mrq->stop = NULL;
-		}
-	}
-
 	if (!present || host->flags & SDHCI_DEVICE_DEAD) {
 		mrq->cmd->error = -ENOMEDIUM;
 		sdhci_finish_mrq(host, mrq);
@@ -2661,6 +2856,17 @@ static bool sdhci_request_done(struct sdhci_host *host)
 	if (host->flags & SDHCI_REQ_USE_DMA) {
 		struct mmc_data *data = mrq->data;
 
+		if (host->use_external_dma && data &&
+		    (mrq->cmd->error || data->error)) {
+			struct dma_chan *chan = sdhci_external_dma_channel(host, data);
+
+			host->mrqs_done[i] = NULL;
+			spin_unlock_irqrestore(&host->lock, flags);
+			dmaengine_terminate_sync(chan);
+			spin_lock_irqsave(&host->lock, flags);
+			sdhci_set_mrq_done(host, mrq);
+		}
+
 		if (data && data->host_cookie == COOKIE_MAPPED) {
 			if (host->bounce_buffer) {
 				/*
@@ -3796,6 +4002,21 @@ int sdhci_setup_host(struct sdhci_host *host)
 	if (sdhci_can_64bit_dma(host))
 		host->flags |= SDHCI_USE_64_BIT_DMA;
 
+	if (host->use_external_dma) {
+		ret = sdhci_external_dma_init(host);
+		if (ret == -EPROBE_DEFER)
+			goto unreg;
+		/*
+		 * Fall back to use the DMA/PIO integrated in standard SDHCI
+		 * instead of external DMA devices.
+		 */
+		else if (ret)
+			sdhci_switch_external_dma(host, false);
+		/* Disable internal DMA sources */
+		else
+			host->flags &= ~(SDHCI_USE_SDMA | SDHCI_USE_ADMA);
+	}
+
 	if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
 		if (host->ops->set_dma_mask)
 			ret = host->ops->set_dma_mask(host);
@@ -3822,15 +4043,13 @@ int sdhci_setup_host(struct sdhci_host *host)
 		dma_addr_t dma;
 		void *buf;
 
-		if (host->flags & SDHCI_USE_64_BIT_DMA) {
-			host->adma_table_sz = host->adma_table_cnt *
-					      SDHCI_ADMA2_64_DESC_SZ(host);
-			host->desc_sz = SDHCI_ADMA2_64_DESC_SZ(host);
-		} else {
-			host->adma_table_sz = host->adma_table_cnt *
-					      SDHCI_ADMA2_32_DESC_SZ;
-			host->desc_sz = SDHCI_ADMA2_32_DESC_SZ;
-		}
+		if (!(host->flags & SDHCI_USE_64_BIT_DMA))
+			host->alloc_desc_sz = SDHCI_ADMA2_32_DESC_SZ;
+		else if (!host->alloc_desc_sz)
+			host->alloc_desc_sz = SDHCI_ADMA2_64_DESC_SZ(host);
+
+		host->desc_sz = host->alloc_desc_sz;
+		host->adma_table_sz = host->adma_table_cnt * host->desc_sz;
 
 		host->align_buffer_sz = SDHCI_MAX_SEGS * SDHCI_ADMA2_ALIGN;
 		/*
@@ -3913,11 +4132,13 @@ int sdhci_setup_host(struct sdhci_host *host)
 	if (host->ops->get_min_clock)
 		mmc->f_min = host->ops->get_min_clock(host);
 	else if (host->version >= SDHCI_SPEC_300) {
-		if (host->clk_mul) {
-			mmc->f_min = (host->max_clk * host->clk_mul) / 1024;
+		if (host->clk_mul)
 			max_clk = host->max_clk * host->clk_mul;
-		} else
-			mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_300;
+		/*
+		 * Divided Clock Mode minimum clock rate is always less than
+		 * Programmable Clock Mode minimum clock rate.
+		 */
+		mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_300;
 	} else
 		mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_200;
 
@@ -4276,6 +4497,10 @@ void sdhci_cleanup_host(struct sdhci_host *host)
 		dma_free_coherent(mmc_dev(mmc), host->align_buffer_sz +
 				  host->adma_table_sz, host->align_buffer,
 				  host->align_addr);
+
+	if (host->use_external_dma)
+		sdhci_external_dma_release(host);
+
 	host->adma_table = NULL;
 	host->align_buffer = NULL;
 }
@@ -4321,6 +4546,7 @@ int __sdhci_add_host(struct sdhci_host *host)
 
 	pr_info("%s: SDHCI controller on %s [%s] using %s\n",
 		mmc_hostname(mmc), host->hw_name, dev_name(mmc_dev(mmc)),
+		host->use_external_dma ? "External DMA" :
 		(host->flags & SDHCI_USE_ADMA) ?
 		(host->flags & SDHCI_USE_64_BIT_DMA) ? "ADMA 64-bit" : "ADMA" :
 		(host->flags & SDHCI_USE_SDMA) ? "DMA" : "PIO");
@@ -4409,6 +4635,9 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
 				  host->adma_table_sz, host->align_buffer,
 				  host->align_addr);
 
+	if (host->use_external_dma)
+		sdhci_external_dma_release(host);
+
 	host->adma_table = NULL;
 	host->align_buffer = NULL;
 }