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* [PATCH] mmc: mmci: Fixup and cleanup code for DMA handling
@ 2012-10-12 15:33 Ulf Hansson
  2012-10-12 21:32 ` Linus Walleij
  0 siblings, 1 reply; 10+ messages in thread
From: Ulf Hansson @ 2012-10-12 15:33 UTC (permalink / raw)
  To: linux-arm-kernel

From: Ulf Hansson <ulf.hansson@linaro.org>

The cookie is now used to indicate if dma_unmap_sg shall be
done in post_request. At DMA errors, the DMA job is immediately
not only terminated but also unmapped. To indicate that this
has been done the cookie is reset to zero. post_request will
thus only do dma_umap_sg for requests which has a cookie not set
to zero.

Some corresponding duplicated code could then be removed and
moreover some corrections at DMA errors for terminating the same
DMA job twice has also been fixed.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Per Forlin <per.forlin@stericsson.com>
---

I realize that this patch is quite extensive to review, but I could not
manage to simplify it further than this. Sorry for that.

Moreover you require the below patch, recently sent to the mmc-list as well,
be able to apply it.

mmc: mmci: Support non-power-of-two block sizes for ux500v2 variant

---
 drivers/mmc/host/mmci.c |  167 ++++++++++++++++++++++++-----------------------
 1 file changed, 85 insertions(+), 82 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index ca6d128..3165808 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -383,10 +383,33 @@ static inline void mmci_dma_release(struct mmci_host *host)
 	host->dma_rx_channel = host->dma_tx_channel = NULL;
 }
 
+static void mmci_dma_data_error(struct mmci_host *host)
+{
+	dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
+	dmaengine_terminate_all(host->dma_current);
+	host->dma_current = NULL;
+	host->dma_desc_current = NULL;
+	host->data->host_cookie = 0;
+}
+
 static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
 {
-	struct dma_chan *chan = host->dma_current;
+	struct dma_chan *chan;
 	enum dma_data_direction dir;
+
+	if (data->flags & MMC_DATA_READ) {
+		dir = DMA_FROM_DEVICE;
+		chan = host->dma_rx_channel;
+	} else {
+		dir = DMA_TO_DEVICE;
+		chan = host->dma_tx_channel;
+	}
+
+	dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
+}
+
+static void mmci_dma_finalize(struct mmci_host *host, struct mmc_data *data)
+{
 	u32 status;
 	int i;
 
@@ -405,19 +428,12 @@ static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
 	 * contiguous buffers.  On TX, we'll get a FIFO underrun error.
 	 */
 	if (status & MCI_RXDATAAVLBLMASK) {
-		dmaengine_terminate_all(chan);
-		if (!data->error)
-			data->error = -EIO;
-	}
-
-	if (data->flags & MMC_DATA_WRITE) {
-		dir = DMA_TO_DEVICE;
-	} else {
-		dir = DMA_FROM_DEVICE;
+		data->error = -EIO;
+		mmci_dma_data_error(host);
 	}
 
 	if (!data->host_cookie)
-		dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
+		mmci_dma_unmap(host, data);
 
 	/*
 	 * Use of DMA with scatter-gather is impossible.
@@ -427,16 +443,15 @@ static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
 		dev_err(mmc_dev(host->mmc), "buggy DMA detected. Taking evasive action.\n");
 		mmci_dma_release(host);
 	}
-}
 
-static void mmci_dma_data_error(struct mmci_host *host)
-{
-	dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
-	dmaengine_terminate_all(host->dma_current);
+	host->dma_current = NULL;
+	host->dma_desc_current = NULL;
 }
 
-static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
-			      struct mmci_host_next *next)
+/* prepares DMA channel and DMA descriptor, returns non-zero on failure */
+static int __mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
+				struct dma_chan **dma_chan,
+				struct dma_async_tx_descriptor **dma_desc)
 {
 	struct variant_data *variant = host->variant;
 	struct dma_slave_config conf = {
@@ -454,16 +469,6 @@ static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
 	enum dma_data_direction buffer_dirn;
 	int nr_sg;
 
-	/* Check if next job is already prepared */
-	if (data->host_cookie && !next &&
-	    host->dma_current && host->dma_desc_current)
-		return 0;
-
-	if (!next) {
-		host->dma_current = NULL;
-		host->dma_desc_current = NULL;
-	}
-
 	if (data->flags & MMC_DATA_READ) {
 		conf.direction = DMA_DEV_TO_MEM;
 		buffer_dirn = DMA_FROM_DEVICE;
@@ -497,30 +502,42 @@ static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
 	if (!desc)
 		goto unmap_exit;
 
-	if (next) {
-		next->dma_chan = chan;
-		next->dma_desc = desc;
-	} else {
-		host->dma_current = chan;
-		host->dma_desc_current = desc;
-	}
+	*dma_chan = chan;
+	*dma_desc = desc;
 
 	return 0;
 
  unmap_exit:
-	if (!next)
-		dmaengine_terminate_all(chan);
 	dma_unmap_sg(device->dev, data->sg, data->sg_len, buffer_dirn);
 	return -ENOMEM;
 }
 
+static inline int mmci_dma_prep_data(struct mmci_host *host,
+				     struct mmc_data *data)
+{
+	/* Check if next job is already prepared. */
+	if (host->dma_current && host->dma_desc_current)
+		return 0;
+
+	/* No job were prepared thus do it now. */
+	return __mmci_dma_prep_data(host, data, &host->dma_current,
+				    &host->dma_desc_current);
+}
+
+static inline int mmci_dma_prep_next(struct mmci_host *host,
+				     struct mmc_data *data)
+{
+	struct mmci_host_next *nd = &host->next_data;
+	return __mmci_dma_prep_data(host, data, &nd->dma_chan, &nd->dma_desc);
+}
+
 static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
 {
 	int ret;
 	struct mmc_data *data = host->data;
 	struct variant_data *variant = host->variant;
 
-	ret = mmci_dma_prep_data(host, host->data, NULL);
+	ret = mmci_dma_prep_data(host, host->data);
 	if (ret)
 		return ret;
 
@@ -555,19 +572,11 @@ static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
 {
 	struct mmci_host_next *next = &host->next_data;
 
-	if (data->host_cookie && data->host_cookie != next->cookie) {
-		pr_warning("[%s] invalid cookie: data->host_cookie %d"
-		       " host->next_data.cookie %d\n",
-		       __func__, data->host_cookie, host->next_data.cookie);
-		data->host_cookie = 0;
-	}
-
-	if (!data->host_cookie)
-		return;
+	WARN_ON(data->host_cookie && data->host_cookie != next->cookie);
+	WARN_ON(!data->host_cookie && (next->dma_desc || next->dma_chan));
 
 	host->dma_desc_current = next->dma_desc;
 	host->dma_current = next->dma_chan;
-
 	next->dma_desc = NULL;
 	next->dma_chan = NULL;
 }
@@ -582,22 +591,13 @@ static void mmci_pre_request(struct mmc_host *mmc, struct mmc_request *mrq,
 	if (!data)
 		return;
 
-	if (mmci_validate_data(host, mrq->data))
-		return;
+	BUG_ON(data->host_cookie);
 
-	if (data->host_cookie) {
-		data->host_cookie = 0;
+	if (mmci_validate_data(host, data))
 		return;
-	}
 
-	/* if config for dma */
-	if (((data->flags & MMC_DATA_WRITE) && host->dma_tx_channel) ||
-	    ((data->flags & MMC_DATA_READ) && host->dma_rx_channel)) {
-		if (mmci_dma_prep_data(host, data, nd))
-			data->host_cookie = 0;
-		else
-			data->host_cookie = ++nd->cookie < 0 ? 1 : nd->cookie;
-	}
+	if (!mmci_dma_prep_next(host, data))
+		data->host_cookie = ++nd->cookie < 0 ? 1 : nd->cookie;
 }
 
 static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
@@ -605,29 +605,23 @@ static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
 {
 	struct mmci_host *host = mmc_priv(mmc);
 	struct mmc_data *data = mrq->data;
-	struct dma_chan *chan;
-	enum dma_data_direction dir;
 
-	if (!data)
+	if (!data || !data->host_cookie)
 		return;
 
-	if (data->flags & MMC_DATA_READ) {
-		dir = DMA_FROM_DEVICE;
-		chan = host->dma_rx_channel;
-	} else {
-		dir = DMA_TO_DEVICE;
-		chan = host->dma_tx_channel;
-	}
+	mmci_dma_unmap(host, data);
 
+	if (err) {
+		struct mmci_host_next *next = &host->next_data;
+		struct dma_chan *chan;
+		if (data->flags & MMC_DATA_READ)
+			chan = host->dma_rx_channel;
+		else
+			chan = host->dma_tx_channel;
+		dmaengine_terminate_all(chan);
 
-	/* if config for dma */
-	if (chan) {
-		if (err)
-			dmaengine_terminate_all(chan);
-		if (data->host_cookie)
-			dma_unmap_sg(mmc_dev(host->mmc), data->sg,
-				     data->sg_len, dir);
-		mrq->data->host_cookie = 0;
+		next->dma_desc = NULL;
+		next->dma_chan = NULL;
 	}
 }
 
@@ -648,6 +642,11 @@ static inline void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
 {
 }
 
+static inline void mmci_dma_finalize(struct mmci_host *host,
+				     struct mmc_data *data)
+{
+}
+
 static inline void mmci_dma_data_error(struct mmci_host *host)
 {
 }
@@ -772,8 +771,10 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
 		u32 remain, success;
 
 		/* Terminate the DMA transfer */
-		if (dma_inprogress(host))
+		if (dma_inprogress(host)) {
 			mmci_dma_data_error(host);
+			mmci_dma_unmap(host, data);
+		}
 
 		/*
 		 * Calculate how far we are into the transfer.  Note that
@@ -812,7 +813,7 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
 
 	if (status & MCI_DATAEND || data->error) {
 		if (dma_inprogress(host))
-			mmci_dma_unmap(host, data);
+			mmci_dma_finalize(host, data);
 		mmci_stop_data(host);
 
 		if (!data->error)
@@ -849,8 +850,10 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	if (!cmd->data || cmd->error) {
 		if (host->data) {
 			/* Terminate the DMA transfer */
-			if (dma_inprogress(host))
+			if (dma_inprogress(host)) {
 				mmci_dma_data_error(host);
+				mmci_dma_unmap(host, host->data);
+			}
 			mmci_stop_data(host);
 		}
 		mmci_request_end(host, cmd->mrq);
-- 
1.7.10

^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH] mmc: mmci: Fixup and cleanup code for DMA handling
@ 2012-12-11 13:06 Ulf Hansson
  0 siblings, 0 replies; 10+ messages in thread
From: Ulf Hansson @ 2012-12-11 13:06 UTC (permalink / raw)
  To: linux-arm-kernel

From: Ulf Hansson <ulf.hansson@linaro.org>

The cookie is now used to indicate if dma_unmap_sg shall be
done in post_request. At DMA errors, the DMA job is immediately
not only terminated but also unmapped. To indicate that this
has been done the cookie is reset to zero. post_request will
thus only do dma_umap_sg for requests which has a cookie not set
to zero.

Some corresponding duplicated code could then be removed and
moreover some corrections at DMA errors for terminating the same
DMA job twice has also been fixed.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Per Forlin <per.forlin@stericsson.com>
---

Changes in v2:
	Rebased patch on top of Linux 3.7

---
 drivers/mmc/host/mmci.c |  190 ++++++++++++++++++++++++++---------------------
 1 file changed, 106 insertions(+), 84 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index aa04b42..cd76793 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -134,6 +134,24 @@ static struct variant_data variant_ux500v2 = {
 };
 
 /*
+ * Validate mmc prerequisites
+ */
+static int mmci_validate_data(struct mmci_host *host,
+			      struct mmc_data *data)
+{
+	if (!data)
+		return 0;
+
+	if (!is_power_of_2(data->blksz)) {
+		dev_err(mmc_dev(host->mmc),
+			"unsupported block size (%d bytes)\n", data->blksz);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
  * This must be called with host->lock held
  */
 static void mmci_write_clkreg(struct mmci_host *host, u32 clk)
@@ -352,10 +370,33 @@ static inline void mmci_dma_release(struct mmci_host *host)
 	host->dma_rx_channel = host->dma_tx_channel = NULL;
 }
 
+static void mmci_dma_data_error(struct mmci_host *host)
+{
+	dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
+	dmaengine_terminate_all(host->dma_current);
+	host->dma_current = NULL;
+	host->dma_desc_current = NULL;
+	host->data->host_cookie = 0;
+}
+
 static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
 {
-	struct dma_chan *chan = host->dma_current;
+	struct dma_chan *chan;
 	enum dma_data_direction dir;
+
+	if (data->flags & MMC_DATA_READ) {
+		dir = DMA_FROM_DEVICE;
+		chan = host->dma_rx_channel;
+	} else {
+		dir = DMA_TO_DEVICE;
+		chan = host->dma_tx_channel;
+	}
+
+	dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
+}
+
+static void mmci_dma_finalize(struct mmci_host *host, struct mmc_data *data)
+{
 	u32 status;
 	int i;
 
@@ -374,19 +415,12 @@ static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
 	 * contiguous buffers.  On TX, we'll get a FIFO underrun error.
 	 */
 	if (status & MCI_RXDATAAVLBLMASK) {
-		dmaengine_terminate_all(chan);
-		if (!data->error)
-			data->error = -EIO;
-	}
-
-	if (data->flags & MMC_DATA_WRITE) {
-		dir = DMA_TO_DEVICE;
-	} else {
-		dir = DMA_FROM_DEVICE;
+		data->error = -EIO;
+		mmci_dma_data_error(host);
 	}
 
 	if (!data->host_cookie)
-		dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
+		mmci_dma_unmap(host, data);
 
 	/*
 	 * Use of DMA with scatter-gather is impossible.
@@ -396,16 +430,15 @@ static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
 		dev_err(mmc_dev(host->mmc), "buggy DMA detected. Taking evasive action.\n");
 		mmci_dma_release(host);
 	}
-}
 
-static void mmci_dma_data_error(struct mmci_host *host)
-{
-	dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
-	dmaengine_terminate_all(host->dma_current);
+	host->dma_current = NULL;
+	host->dma_desc_current = NULL;
 }
 
-static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
-			      struct mmci_host_next *next)
+/* prepares DMA channel and DMA descriptor, returns non-zero on failure */
+static int __mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
+				struct dma_chan **dma_chan,
+				struct dma_async_tx_descriptor **dma_desc)
 {
 	struct variant_data *variant = host->variant;
 	struct dma_slave_config conf = {
@@ -423,16 +456,6 @@ static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
 	enum dma_data_direction buffer_dirn;
 	int nr_sg;
 
-	/* Check if next job is already prepared */
-	if (data->host_cookie && !next &&
-	    host->dma_current && host->dma_desc_current)
-		return 0;
-
-	if (!next) {
-		host->dma_current = NULL;
-		host->dma_desc_current = NULL;
-	}
-
 	if (data->flags & MMC_DATA_READ) {
 		conf.direction = DMA_DEV_TO_MEM;
 		buffer_dirn = DMA_FROM_DEVICE;
@@ -462,29 +485,41 @@ static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
 	if (!desc)
 		goto unmap_exit;
 
-	if (next) {
-		next->dma_chan = chan;
-		next->dma_desc = desc;
-	} else {
-		host->dma_current = chan;
-		host->dma_desc_current = desc;
-	}
+	*dma_chan = chan;
+	*dma_desc = desc;
 
 	return 0;
 
  unmap_exit:
-	if (!next)
-		dmaengine_terminate_all(chan);
 	dma_unmap_sg(device->dev, data->sg, data->sg_len, buffer_dirn);
 	return -ENOMEM;
 }
 
+static inline int mmci_dma_prep_data(struct mmci_host *host,
+				     struct mmc_data *data)
+{
+	/* Check if next job is already prepared. */
+	if (host->dma_current && host->dma_desc_current)
+		return 0;
+
+	/* No job were prepared thus do it now. */
+	return __mmci_dma_prep_data(host, data, &host->dma_current,
+				    &host->dma_desc_current);
+}
+
+static inline int mmci_dma_prep_next(struct mmci_host *host,
+				     struct mmc_data *data)
+{
+	struct mmci_host_next *nd = &host->next_data;
+	return __mmci_dma_prep_data(host, data, &nd->dma_chan, &nd->dma_desc);
+}
+
 static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
 {
 	int ret;
 	struct mmc_data *data = host->data;
 
-	ret = mmci_dma_prep_data(host, host->data, NULL);
+	ret = mmci_dma_prep_data(host, host->data);
 	if (ret)
 		return ret;
 
@@ -514,19 +549,11 @@ static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
 {
 	struct mmci_host_next *next = &host->next_data;
 
-	if (data->host_cookie && data->host_cookie != next->cookie) {
-		pr_warning("[%s] invalid cookie: data->host_cookie %d"
-		       " host->next_data.cookie %d\n",
-		       __func__, data->host_cookie, host->next_data.cookie);
-		data->host_cookie = 0;
-	}
-
-	if (!data->host_cookie)
-		return;
+	WARN_ON(data->host_cookie && data->host_cookie != next->cookie);
+	WARN_ON(!data->host_cookie && (next->dma_desc || next->dma_chan));
 
 	host->dma_desc_current = next->dma_desc;
 	host->dma_current = next->dma_chan;
-
 	next->dma_desc = NULL;
 	next->dma_chan = NULL;
 }
@@ -541,19 +568,13 @@ static void mmci_pre_request(struct mmc_host *mmc, struct mmc_request *mrq,
 	if (!data)
 		return;
 
-	if (data->host_cookie) {
-		data->host_cookie = 0;
+	BUG_ON(data->host_cookie);
+
+	if (mmci_validate_data(host, data))
 		return;
-	}
 
-	/* if config for dma */
-	if (((data->flags & MMC_DATA_WRITE) && host->dma_tx_channel) ||
-	    ((data->flags & MMC_DATA_READ) && host->dma_rx_channel)) {
-		if (mmci_dma_prep_data(host, data, nd))
-			data->host_cookie = 0;
-		else
-			data->host_cookie = ++nd->cookie < 0 ? 1 : nd->cookie;
-	}
+	if (!mmci_dma_prep_next(host, data))
+		data->host_cookie = ++nd->cookie < 0 ? 1 : nd->cookie;
 }
 
 static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
@@ -561,29 +582,23 @@ static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
 {
 	struct mmci_host *host = mmc_priv(mmc);
 	struct mmc_data *data = mrq->data;
-	struct dma_chan *chan;
-	enum dma_data_direction dir;
 
-	if (!data)
+	if (!data || !data->host_cookie)
 		return;
 
-	if (data->flags & MMC_DATA_READ) {
-		dir = DMA_FROM_DEVICE;
-		chan = host->dma_rx_channel;
-	} else {
-		dir = DMA_TO_DEVICE;
-		chan = host->dma_tx_channel;
-	}
+	mmci_dma_unmap(host, data);
 
+	if (err) {
+		struct mmci_host_next *next = &host->next_data;
+		struct dma_chan *chan;
+		if (data->flags & MMC_DATA_READ)
+			chan = host->dma_rx_channel;
+		else
+			chan = host->dma_tx_channel;
+		dmaengine_terminate_all(chan);
 
-	/* if config for dma */
-	if (chan) {
-		if (err)
-			dmaengine_terminate_all(chan);
-		if (data->host_cookie)
-			dma_unmap_sg(mmc_dev(host->mmc), data->sg,
-				     data->sg_len, dir);
-		mrq->data->host_cookie = 0;
+		next->dma_desc = NULL;
+		next->dma_chan = NULL;
 	}
 }
 
@@ -604,6 +619,11 @@ static inline void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
 {
 }
 
+static inline void mmci_dma_finalize(struct mmci_host *host,
+				     struct mmc_data *data)
+{
+}
+
 static inline void mmci_dma_data_error(struct mmci_host *host)
 {
 }
@@ -751,8 +771,10 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
 		u32 remain, success;
 
 		/* Terminate the DMA transfer */
-		if (dma_inprogress(host))
+		if (dma_inprogress(host)) {
 			mmci_dma_data_error(host);
+			mmci_dma_unmap(host, data);
+		}
 
 		/*
 		 * Calculate how far we are into the transfer.  Note that
@@ -791,7 +813,7 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
 
 	if (status & MCI_DATAEND || data->error) {
 		if (dma_inprogress(host))
-			mmci_dma_unmap(host, data);
+			mmci_dma_finalize(host, data);
 		mmci_stop_data(host);
 
 		if (!data->error)
@@ -828,8 +850,10 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	if (!cmd->data || cmd->error) {
 		if (host->data) {
 			/* Terminate the DMA transfer */
-			if (dma_inprogress(host))
+			if (dma_inprogress(host)) {
 				mmci_dma_data_error(host);
+				mmci_dma_unmap(host, host->data);
+			}
 			mmci_stop_data(host);
 		}
 		mmci_request_end(host, cmd->mrq);
@@ -1055,10 +1079,8 @@ static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 
 	WARN_ON(host->mrq != NULL);
 
-	if (mrq->data && !is_power_of_2(mrq->data->blksz)) {
-		dev_err(mmc_dev(mmc), "unsupported block size (%d bytes)\n",
-			mrq->data->blksz);
-		mrq->cmd->error = -EINVAL;
+	mrq->cmd->error = mmci_validate_data(host, mrq->data);
+	if (mrq->cmd->error) {
 		mmc_request_done(mmc, mrq);
 		return;
 	}
-- 
1.7.10

^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH] mmc: mmci: Fixup and cleanup code for DMA handling
@ 2013-01-21 20:15 Ulf Hansson
  0 siblings, 0 replies; 10+ messages in thread
From: Ulf Hansson @ 2013-01-21 20:15 UTC (permalink / raw)
  To: linux-arm-kernel

From: Ulf Hansson <ulf.hansson@linaro.org>

The cookie is now used to indicate if dma_unmap_sg shall be
done in post_request. At DMA errors, the DMA job is immediately
not only terminated but also unmapped. To indicate that this
has been done the cookie is reset to zero. post_request will
thus only do dma_umap_sg for requests which has a cookie not set
to zero.

Some corresponding duplicated code could then be removed and
moreover some corrections at DMA errors for terminating the same
DMA job twice has also been fixed.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Per Forlin <per.forlin@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
---
This patch has been tested both on a u8500 board and an ARM-RealView
PB1176 board.

Changes in v4:
	Keep behavior were error code was not overwritten in dma_finalize.
        Rebased on top of Linux 3.8-rc4.

Changes in v3:
        Add ack from Linus Walleij.
        Rebased on top of Linux 3.8-rc2

Changes in v2:
        Rebased patch on top of Linux 3.7

---
 drivers/mmc/host/mmci.c |  187 ++++++++++++++++++++++++++---------------------
 1 file changed, 105 insertions(+), 82 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 1507723..f910a37 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -134,6 +134,24 @@ static struct variant_data variant_ux500v2 = {
 };
 
 /*
+ * Validate mmc prerequisites
+ */
+static int mmci_validate_data(struct mmci_host *host,
+			      struct mmc_data *data)
+{
+	if (!data)
+		return 0;
+
+	if (!is_power_of_2(data->blksz)) {
+		dev_err(mmc_dev(host->mmc),
+			"unsupported block size (%d bytes)\n", data->blksz);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
  * This must be called with host->lock held
  */
 static void mmci_write_clkreg(struct mmci_host *host, u32 clk)
@@ -352,10 +370,33 @@ static inline void mmci_dma_release(struct mmci_host *host)
 	host->dma_rx_channel = host->dma_tx_channel = NULL;
 }
 
+static void mmci_dma_data_error(struct mmci_host *host)
+{
+	dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
+	dmaengine_terminate_all(host->dma_current);
+	host->dma_current = NULL;
+	host->dma_desc_current = NULL;
+	host->data->host_cookie = 0;
+}
+
 static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
 {
-	struct dma_chan *chan = host->dma_current;
+	struct dma_chan *chan;
 	enum dma_data_direction dir;
+
+	if (data->flags & MMC_DATA_READ) {
+		dir = DMA_FROM_DEVICE;
+		chan = host->dma_rx_channel;
+	} else {
+		dir = DMA_TO_DEVICE;
+		chan = host->dma_tx_channel;
+	}
+
+	dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
+}
+
+static void mmci_dma_finalize(struct mmci_host *host, struct mmc_data *data)
+{
 	u32 status;
 	int i;
 
@@ -374,19 +415,13 @@ static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
 	 * contiguous buffers.  On TX, we'll get a FIFO underrun error.
 	 */
 	if (status & MCI_RXDATAAVLBLMASK) {
-		dmaengine_terminate_all(chan);
+		mmci_dma_data_error(host);
 		if (!data->error)
 			data->error = -EIO;
 	}
 
-	if (data->flags & MMC_DATA_WRITE) {
-		dir = DMA_TO_DEVICE;
-	} else {
-		dir = DMA_FROM_DEVICE;
-	}
-
 	if (!data->host_cookie)
-		dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
+		mmci_dma_unmap(host, data);
 
 	/*
 	 * Use of DMA with scatter-gather is impossible.
@@ -396,16 +431,15 @@ static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
 		dev_err(mmc_dev(host->mmc), "buggy DMA detected. Taking evasive action.\n");
 		mmci_dma_release(host);
 	}
-}
 
-static void mmci_dma_data_error(struct mmci_host *host)
-{
-	dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
-	dmaengine_terminate_all(host->dma_current);
+	host->dma_current = NULL;
+	host->dma_desc_current = NULL;
 }
 
-static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
-			      struct mmci_host_next *next)
+/* prepares DMA channel and DMA descriptor, returns non-zero on failure */
+static int __mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
+				struct dma_chan **dma_chan,
+				struct dma_async_tx_descriptor **dma_desc)
 {
 	struct variant_data *variant = host->variant;
 	struct dma_slave_config conf = {
@@ -423,16 +457,6 @@ static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
 	enum dma_data_direction buffer_dirn;
 	int nr_sg;
 
-	/* Check if next job is already prepared */
-	if (data->host_cookie && !next &&
-	    host->dma_current && host->dma_desc_current)
-		return 0;
-
-	if (!next) {
-		host->dma_current = NULL;
-		host->dma_desc_current = NULL;
-	}
-
 	if (data->flags & MMC_DATA_READ) {
 		conf.direction = DMA_DEV_TO_MEM;
 		buffer_dirn = DMA_FROM_DEVICE;
@@ -462,29 +486,41 @@ static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
 	if (!desc)
 		goto unmap_exit;
 
-	if (next) {
-		next->dma_chan = chan;
-		next->dma_desc = desc;
-	} else {
-		host->dma_current = chan;
-		host->dma_desc_current = desc;
-	}
+	*dma_chan = chan;
+	*dma_desc = desc;
 
 	return 0;
 
  unmap_exit:
-	if (!next)
-		dmaengine_terminate_all(chan);
 	dma_unmap_sg(device->dev, data->sg, data->sg_len, buffer_dirn);
 	return -ENOMEM;
 }
 
+static inline int mmci_dma_prep_data(struct mmci_host *host,
+				     struct mmc_data *data)
+{
+	/* Check if next job is already prepared. */
+	if (host->dma_current && host->dma_desc_current)
+		return 0;
+
+	/* No job were prepared thus do it now. */
+	return __mmci_dma_prep_data(host, data, &host->dma_current,
+				    &host->dma_desc_current);
+}
+
+static inline int mmci_dma_prep_next(struct mmci_host *host,
+				     struct mmc_data *data)
+{
+	struct mmci_host_next *nd = &host->next_data;
+	return __mmci_dma_prep_data(host, data, &nd->dma_chan, &nd->dma_desc);
+}
+
 static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
 {
 	int ret;
 	struct mmc_data *data = host->data;
 
-	ret = mmci_dma_prep_data(host, host->data, NULL);
+	ret = mmci_dma_prep_data(host, host->data);
 	if (ret)
 		return ret;
 
@@ -514,19 +550,11 @@ static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
 {
 	struct mmci_host_next *next = &host->next_data;
 
-	if (data->host_cookie && data->host_cookie != next->cookie) {
-		pr_warning("[%s] invalid cookie: data->host_cookie %d"
-		       " host->next_data.cookie %d\n",
-		       __func__, data->host_cookie, host->next_data.cookie);
-		data->host_cookie = 0;
-	}
-
-	if (!data->host_cookie)
-		return;
+	WARN_ON(data->host_cookie && data->host_cookie != next->cookie);
+	WARN_ON(!data->host_cookie && (next->dma_desc || next->dma_chan));
 
 	host->dma_desc_current = next->dma_desc;
 	host->dma_current = next->dma_chan;
-
 	next->dma_desc = NULL;
 	next->dma_chan = NULL;
 }
@@ -541,19 +569,13 @@ static void mmci_pre_request(struct mmc_host *mmc, struct mmc_request *mrq,
 	if (!data)
 		return;
 
-	if (data->host_cookie) {
-		data->host_cookie = 0;
+	BUG_ON(data->host_cookie);
+
+	if (mmci_validate_data(host, data))
 		return;
-	}
 
-	/* if config for dma */
-	if (((data->flags & MMC_DATA_WRITE) && host->dma_tx_channel) ||
-	    ((data->flags & MMC_DATA_READ) && host->dma_rx_channel)) {
-		if (mmci_dma_prep_data(host, data, nd))
-			data->host_cookie = 0;
-		else
-			data->host_cookie = ++nd->cookie < 0 ? 1 : nd->cookie;
-	}
+	if (!mmci_dma_prep_next(host, data))
+		data->host_cookie = ++nd->cookie < 0 ? 1 : nd->cookie;
 }
 
 static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
@@ -561,29 +583,23 @@ static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
 {
 	struct mmci_host *host = mmc_priv(mmc);
 	struct mmc_data *data = mrq->data;
-	struct dma_chan *chan;
-	enum dma_data_direction dir;
 
-	if (!data)
+	if (!data || !data->host_cookie)
 		return;
 
-	if (data->flags & MMC_DATA_READ) {
-		dir = DMA_FROM_DEVICE;
-		chan = host->dma_rx_channel;
-	} else {
-		dir = DMA_TO_DEVICE;
-		chan = host->dma_tx_channel;
-	}
+	mmci_dma_unmap(host, data);
 
+	if (err) {
+		struct mmci_host_next *next = &host->next_data;
+		struct dma_chan *chan;
+		if (data->flags & MMC_DATA_READ)
+			chan = host->dma_rx_channel;
+		else
+			chan = host->dma_tx_channel;
+		dmaengine_terminate_all(chan);
 
-	/* if config for dma */
-	if (chan) {
-		if (err)
-			dmaengine_terminate_all(chan);
-		if (data->host_cookie)
-			dma_unmap_sg(mmc_dev(host->mmc), data->sg,
-				     data->sg_len, dir);
-		mrq->data->host_cookie = 0;
+		next->dma_desc = NULL;
+		next->dma_chan = NULL;
 	}
 }
 
@@ -604,6 +620,11 @@ static inline void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
 {
 }
 
+static inline void mmci_dma_finalize(struct mmci_host *host,
+				     struct mmc_data *data)
+{
+}
+
 static inline void mmci_dma_data_error(struct mmci_host *host)
 {
 }
@@ -751,8 +772,10 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
 		u32 remain, success;
 
 		/* Terminate the DMA transfer */
-		if (dma_inprogress(host))
+		if (dma_inprogress(host)) {
 			mmci_dma_data_error(host);
+			mmci_dma_unmap(host, data);
+		}
 
 		/*
 		 * Calculate how far we are into the transfer.  Note that
@@ -791,7 +814,7 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
 
 	if (status & MCI_DATAEND || data->error) {
 		if (dma_inprogress(host))
-			mmci_dma_unmap(host, data);
+			mmci_dma_finalize(host, data);
 		mmci_stop_data(host);
 
 		if (!data->error)
@@ -828,8 +851,10 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	if (!cmd->data || cmd->error) {
 		if (host->data) {
 			/* Terminate the DMA transfer */
-			if (dma_inprogress(host))
+			if (dma_inprogress(host)) {
 				mmci_dma_data_error(host);
+				mmci_dma_unmap(host, host->data);
+			}
 			mmci_stop_data(host);
 		}
 		mmci_request_end(host, cmd->mrq);
@@ -1055,10 +1080,8 @@ static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 
 	WARN_ON(host->mrq != NULL);
 
-	if (mrq->data && !is_power_of_2(mrq->data->blksz)) {
-		dev_err(mmc_dev(mmc), "unsupported block size (%d bytes)\n",
-			mrq->data->blksz);
-		mrq->cmd->error = -EINVAL;
+	mrq->cmd->error = mmci_validate_data(host, mrq->data);
+	if (mrq->cmd->error) {
 		mmc_request_done(mmc, mrq);
 		return;
 	}
-- 
1.7.10

^ permalink raw reply related	[flat|nested] 10+ messages in thread
end of thread, other threads:[~2013-01-21 20:15 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-10-12 15:33 [PATCH] mmc: mmci: Fixup and cleanup code for DMA handling Ulf Hansson
2012-10-12 21:32 ` Linus Walleij
2012-10-16  7:16   ` Ulf Hansson
2012-10-16  8:17     ` Linus Walleij
2012-10-16 11:44       ` Ulf Hansson
2012-11-21 15:22         ` Ulf Hansson
2012-11-28 14:00           ` Ulf Hansson
2012-12-13 10:59             ` Ulf Hansson
  -- strict thread matches above, loose matches on Subject: below --
2012-12-11 13:06 Ulf Hansson
2013-01-21 20:15 Ulf Hansson

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