mmc: sdhci: Avoid swiotlb buffer being full

Message ID 1511778530-6761-1-git-send-email-ulf.hansson@linaro.org
State New
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Series
  • mmc: sdhci: Avoid swiotlb buffer being full
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Commit Message

Ulf Hansson Nov. 27, 2017, 10:28 a.m.
The commit de3ee99b097d ("mmc: Delete bounce buffer handling") deletes the
bounce buffer handling, but also causes the max_req_size for sdhci to be
increased, in case when max_segs == 1. This causes errors for sdhci-pci
Ricoh variant, about the swiotlb buffer to become full.

Fix the issue, by taking IO_TLB_SEGSIZE and IO_TLB_SHIFT into account when
deciding the max_req_size for sdhci.

Reported-by: Jiri Slaby <jslaby@suse.cz>
Fixes: de3ee99b097d ("mmc: Delete bounce buffer handling")
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Tested-by: Jiri Slaby <jslaby@suse.cz>

---
 drivers/mmc/host/sdhci.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

-- 
2.7.4

Comments

Adrian Hunter Nov. 27, 2017, 12:42 p.m. | #1
On 27/11/17 12:28, Ulf Hansson wrote:
> The commit de3ee99b097d ("mmc: Delete bounce buffer handling") deletes the

> bounce buffer handling, but also causes the max_req_size for sdhci to be

> increased, in case when max_segs == 1. This causes errors for sdhci-pci

> Ricoh variant, about the swiotlb buffer to become full.

> 

> Fix the issue, by taking IO_TLB_SEGSIZE and IO_TLB_SHIFT into account when

> deciding the max_req_size for sdhci.

> 

> Reported-by: Jiri Slaby <jslaby@suse.cz>

> Fixes: de3ee99b097d ("mmc: Delete bounce buffer handling")

> Cc: <stable@vger.kernel.org> # v4.14+

> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

> Tested-by: Jiri Slaby <jslaby@suse.cz>


Acked-by: Adrian Hunter <adrian.hunter@intel.com>


> ---

>  drivers/mmc/host/sdhci.c | 28 ++++++++++++++++++----------

>  1 file changed, 18 insertions(+), 10 deletions(-)

> 

> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c

> index 2f14334..e9290a3 100644

> --- a/drivers/mmc/host/sdhci.c

> +++ b/drivers/mmc/host/sdhci.c

> @@ -21,6 +21,7 @@

>  #include <linux/dma-mapping.h>

>  #include <linux/slab.h>

>  #include <linux/scatterlist.h>

> +#include <linux/swiotlb.h>

>  #include <linux/regulator/consumer.h>

>  #include <linux/pm_runtime.h>

>  #include <linux/of.h>

> @@ -3651,22 +3652,29 @@ int sdhci_setup_host(struct sdhci_host *host)

>  	spin_lock_init(&host->lock);

>  

>  	/*

> +	 * Maximum number of sectors in one transfer. Limited by SDMA boundary

> +	 * size (512KiB). Note some tuning modes impose a 4MiB limit, but this

> +	 * is less anyway.

> +	 */

> +	mmc->max_req_size = 524288;

> +

> +	/*

>  	 * Maximum number of segments. Depends on if the hardware

>  	 * can do scatter/gather or not.

>  	 */

> -	if (host->flags & SDHCI_USE_ADMA)

> +	if (host->flags & SDHCI_USE_ADMA) {

>  		mmc->max_segs = SDHCI_MAX_SEGS;

> -	else if (host->flags & SDHCI_USE_SDMA)

> +	} else if (host->flags & SDHCI_USE_SDMA) {

>  		mmc->max_segs = 1;

> -	else /* PIO */

> +		if (swiotlb_max_segment()) {

> +			unsigned int max_req_size = (1 << IO_TLB_SHIFT) *

> +						IO_TLB_SEGSIZE;

> +			mmc->max_req_size = min(mmc->max_req_size,

> +						max_req_size);

> +		}

> +	} else { /* PIO */

>  		mmc->max_segs = SDHCI_MAX_SEGS;

> -

> -	/*

> -	 * Maximum number of sectors in one transfer. Limited by SDMA boundary

> -	 * size (512KiB). Note some tuning modes impose a 4MiB limit, but this

> -	 * is less anyway.

> -	 */

> -	mmc->max_req_size = 524288;

> +	}

>  

>  	/*

>  	 * Maximum segment size. Could be one segment with the maximum number

> 


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Patch

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 2f14334..e9290a3 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -21,6 +21,7 @@ 
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
 #include <linux/scatterlist.h>
+#include <linux/swiotlb.h>
 #include <linux/regulator/consumer.h>
 #include <linux/pm_runtime.h>
 #include <linux/of.h>
@@ -3651,22 +3652,29 @@  int sdhci_setup_host(struct sdhci_host *host)
 	spin_lock_init(&host->lock);
 
 	/*
+	 * Maximum number of sectors in one transfer. Limited by SDMA boundary
+	 * size (512KiB). Note some tuning modes impose a 4MiB limit, but this
+	 * is less anyway.
+	 */
+	mmc->max_req_size = 524288;
+
+	/*
 	 * Maximum number of segments. Depends on if the hardware
 	 * can do scatter/gather or not.
 	 */
-	if (host->flags & SDHCI_USE_ADMA)
+	if (host->flags & SDHCI_USE_ADMA) {
 		mmc->max_segs = SDHCI_MAX_SEGS;
-	else if (host->flags & SDHCI_USE_SDMA)
+	} else if (host->flags & SDHCI_USE_SDMA) {
 		mmc->max_segs = 1;
-	else /* PIO */
+		if (swiotlb_max_segment()) {
+			unsigned int max_req_size = (1 << IO_TLB_SHIFT) *
+						IO_TLB_SEGSIZE;
+			mmc->max_req_size = min(mmc->max_req_size,
+						max_req_size);
+		}
+	} else { /* PIO */
 		mmc->max_segs = SDHCI_MAX_SEGS;
-
-	/*
-	 * Maximum number of sectors in one transfer. Limited by SDMA boundary
-	 * size (512KiB). Note some tuning modes impose a 4MiB limit, but this
-	 * is less anyway.
-	 */
-	mmc->max_req_size = 524288;
+	}
 
 	/*
 	 * Maximum segment size. Could be one segment with the maximum number