diff mbox series

[V2] mmc: sdhci: Check for reset prior to DMA address unmap

Message ID 1614760331-43499-1-git-send-email-pragalla@qti.qualcomm.com
State New
Headers show
Series [V2] mmc: sdhci: Check for reset prior to DMA address unmap | expand

Commit Message

Pradeep P V K March 3, 2021, 8:32 a.m. UTC
From: Pradeep P V K <pragalla@codeaurora.org>

For data read commands, SDHC may initiate data transfers even before it
completely process the command response. In case command itself fails,
driver un-maps the memory associated with data transfer but this memory
can still be accessed by SDHC for the already initiated data transfer.
This scenario can lead to un-mapped memory access error.

To avoid this scenario, reset SDHC (when command fails) prior to
un-mapping memory. Resetting SDHC ensures that all in-flight data
transfers are either aborted or completed. So we don't run into this
scenario.

Swap the reset, un-map steps sequence in sdhci_request_done().

Changes since V1:
- Added an empty line and fixed the comment style.
- Retained the Acked-by signoff.

Suggested-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Signed-off-by: Pradeep P V K <pragalla@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 60 +++++++++++++++++++++++++-----------------------
 1 file changed, 31 insertions(+), 29 deletions(-)

Comments

Ulf Hansson March 4, 2021, 1:49 p.m. UTC | #1
On Wed, 3 Mar 2021 at 09:32, Pradeep P V K <pragalla@qti.qualcomm.com> wrote:
>

> From: Pradeep P V K <pragalla@codeaurora.org>

>

> For data read commands, SDHC may initiate data transfers even before it

> completely process the command response. In case command itself fails,

> driver un-maps the memory associated with data transfer but this memory

> can still be accessed by SDHC for the already initiated data transfer.

> This scenario can lead to un-mapped memory access error.

>

> To avoid this scenario, reset SDHC (when command fails) prior to

> un-mapping memory. Resetting SDHC ensures that all in-flight data

> transfers are either aborted or completed. So we don't run into this

> scenario.

>

> Swap the reset, un-map steps sequence in sdhci_request_done().

>

> Changes since V1:

> - Added an empty line and fixed the comment style.

> - Retained the Acked-by signoff.

>

> Suggested-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>

> Signed-off-by: Pradeep P V K <pragalla@codeaurora.org>

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


Seems like it might be a good idea to tag this for stable? I did that,
but awaiting for your confirmation.

So, applied for next, thanks!

Kind regards
Uffe


> ---

>  drivers/mmc/host/sdhci.c | 60 +++++++++++++++++++++++++-----------------------

>  1 file changed, 31 insertions(+), 29 deletions(-)

>

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

> index 646823d..130fd2d 100644

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

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

> @@ -2998,6 +2998,37 @@ static bool sdhci_request_done(struct sdhci_host *host)

>         }

>

>         /*

> +        * The controller needs a reset of internal state machines

> +        * upon error conditions.

> +        */

> +       if (sdhci_needs_reset(host, mrq)) {

> +               /*

> +                * Do not finish until command and data lines are available for

> +                * reset. Note there can only be one other mrq, so it cannot

> +                * also be in mrqs_done, otherwise host->cmd and host->data_cmd

> +                * would both be null.

> +                */

> +               if (host->cmd || host->data_cmd) {

> +                       spin_unlock_irqrestore(&host->lock, flags);

> +                       return true;

> +               }

> +

> +               /* Some controllers need this kick or reset won't work here */

> +               if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)

> +                       /* This is to force an update */

> +                       host->ops->set_clock(host, host->clock);

> +

> +               /*

> +                * Spec says we should do both at the same time, but Ricoh

> +                * controllers do not like that.

> +                */

> +               sdhci_do_reset(host, SDHCI_RESET_CMD);

> +               sdhci_do_reset(host, SDHCI_RESET_DATA);

> +

> +               host->pending_reset = false;

> +       }

> +

> +       /*

>          * Always unmap the data buffers if they were mapped by

>          * sdhci_prepare_data() whenever we finish with a request.

>          * This avoids leaking DMA mappings on error.

> @@ -3060,35 +3091,6 @@ static bool sdhci_request_done(struct sdhci_host *host)

>                 }

>         }

>

> -       /*

> -        * The controller needs a reset of internal state machines

> -        * upon error conditions.

> -        */

> -       if (sdhci_needs_reset(host, mrq)) {

> -               /*

> -                * Do not finish until command and data lines are available for

> -                * reset. Note there can only be one other mrq, so it cannot

> -                * also be in mrqs_done, otherwise host->cmd and host->data_cmd

> -                * would both be null.

> -                */

> -               if (host->cmd || host->data_cmd) {

> -                       spin_unlock_irqrestore(&host->lock, flags);

> -                       return true;

> -               }

> -

> -               /* Some controllers need this kick or reset won't work here */

> -               if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)

> -                       /* This is to force an update */

> -                       host->ops->set_clock(host, host->clock);

> -

> -               /* Spec says we should do both at the same time, but Ricoh

> -                  controllers do not like that. */

> -               sdhci_do_reset(host, SDHCI_RESET_CMD);

> -               sdhci_do_reset(host, SDHCI_RESET_DATA);

> -

> -               host->pending_reset = false;

> -       }

> -

>         host->mrqs_done[i] = NULL;

>

>         spin_unlock_irqrestore(&host->lock, flags);

> --

> 2.7.4

>
Pradeep P V K March 4, 2021, 3:16 p.m. UTC | #2
On 2021-03-04 19:19, Ulf Hansson wrote:
> On Wed, 3 Mar 2021 at 09:32, Pradeep P V K <pragalla@qti.qualcomm.com> 

> wrote:

>> 

>> From: Pradeep P V K <pragalla@codeaurora.org>

>> 

>> For data read commands, SDHC may initiate data transfers even before 

>> it

>> completely process the command response. In case command itself fails,

>> driver un-maps the memory associated with data transfer but this 

>> memory

>> can still be accessed by SDHC for the already initiated data transfer.

>> This scenario can lead to un-mapped memory access error.

>> 

>> To avoid this scenario, reset SDHC (when command fails) prior to

>> un-mapping memory. Resetting SDHC ensures that all in-flight data

>> transfers are either aborted or completed. So we don't run into this

>> scenario.

>> 

>> Swap the reset, un-map steps sequence in sdhci_request_done().

>> 

>> Changes since V1:

>> - Added an empty line and fixed the comment style.

>> - Retained the Acked-by signoff.

>> 

>> Suggested-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>

>> Signed-off-by: Pradeep P V K <pragalla@codeaurora.org>

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


Hi Uffe,
> 

> Seems like it might be a good idea to tag this for stable? I did that,

> but awaiting for your confirmation.

> 

Yes, this fix is applicable for all stable starting from 4.9 (n/a for 
4.4).
Kindly go ahead.

> So, applied for next, thanks!

> 

> Kind regards

> Uffe

> 

Thanks and Regards,
Pradeep

> 

>> ---

>>  drivers/mmc/host/sdhci.c | 60 

>> +++++++++++++++++++++++++-----------------------

>>  1 file changed, 31 insertions(+), 29 deletions(-)

>> 

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

>> index 646823d..130fd2d 100644

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

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

>> @@ -2998,6 +2998,37 @@ static bool sdhci_request_done(struct 

>> sdhci_host *host)

>>         }

>> 

>>         /*

>> +        * The controller needs a reset of internal state machines

>> +        * upon error conditions.

>> +        */

>> +       if (sdhci_needs_reset(host, mrq)) {

>> +               /*

>> +                * Do not finish until command and data lines are 

>> available for

>> +                * reset. Note there can only be one other mrq, so it 

>> cannot

>> +                * also be in mrqs_done, otherwise host->cmd and 

>> host->data_cmd

>> +                * would both be null.

>> +                */

>> +               if (host->cmd || host->data_cmd) {

>> +                       spin_unlock_irqrestore(&host->lock, flags);

>> +                       return true;

>> +               }

>> +

>> +               /* Some controllers need this kick or reset won't work 

>> here */

>> +               if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)

>> +                       /* This is to force an update */

>> +                       host->ops->set_clock(host, host->clock);

>> +

>> +               /*

>> +                * Spec says we should do both at the same time, but 

>> Ricoh

>> +                * controllers do not like that.

>> +                */

>> +               sdhci_do_reset(host, SDHCI_RESET_CMD);

>> +               sdhci_do_reset(host, SDHCI_RESET_DATA);

>> +

>> +               host->pending_reset = false;

>> +       }

>> +

>> +       /*

>>          * Always unmap the data buffers if they were mapped by

>>          * sdhci_prepare_data() whenever we finish with a request.

>>          * This avoids leaking DMA mappings on error.

>> @@ -3060,35 +3091,6 @@ static bool sdhci_request_done(struct 

>> sdhci_host *host)

>>                 }

>>         }

>> 

>> -       /*

>> -        * The controller needs a reset of internal state machines

>> -        * upon error conditions.

>> -        */

>> -       if (sdhci_needs_reset(host, mrq)) {

>> -               /*

>> -                * Do not finish until command and data lines are 

>> available for

>> -                * reset. Note there can only be one other mrq, so it 

>> cannot

>> -                * also be in mrqs_done, otherwise host->cmd and 

>> host->data_cmd

>> -                * would both be null.

>> -                */

>> -               if (host->cmd || host->data_cmd) {

>> -                       spin_unlock_irqrestore(&host->lock, flags);

>> -                       return true;

>> -               }

>> -

>> -               /* Some controllers need this kick or reset won't work 

>> here */

>> -               if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)

>> -                       /* This is to force an update */

>> -                       host->ops->set_clock(host, host->clock);

>> -

>> -               /* Spec says we should do both at the same time, but 

>> Ricoh

>> -                  controllers do not like that. */

>> -               sdhci_do_reset(host, SDHCI_RESET_CMD);

>> -               sdhci_do_reset(host, SDHCI_RESET_DATA);

>> -

>> -               host->pending_reset = false;

>> -       }

>> -

>>         host->mrqs_done[i] = NULL;

>> 

>>         spin_unlock_irqrestore(&host->lock, flags);

>> --

>> 2.7.4

>>
Ulf Hansson March 4, 2021, 6:08 p.m. UTC | #3
On Thu, 4 Mar 2021 at 16:16, <pragalla@codeaurora.org> wrote:
>

> On 2021-03-04 19:19, Ulf Hansson wrote:

> > On Wed, 3 Mar 2021 at 09:32, Pradeep P V K <pragalla@qti.qualcomm.com>

> > wrote:

> >>

> >> From: Pradeep P V K <pragalla@codeaurora.org>

> >>

> >> For data read commands, SDHC may initiate data transfers even before

> >> it

> >> completely process the command response. In case command itself fails,

> >> driver un-maps the memory associated with data transfer but this

> >> memory

> >> can still be accessed by SDHC for the already initiated data transfer.

> >> This scenario can lead to un-mapped memory access error.

> >>

> >> To avoid this scenario, reset SDHC (when command fails) prior to

> >> un-mapping memory. Resetting SDHC ensures that all in-flight data

> >> transfers are either aborted or completed. So we don't run into this

> >> scenario.

> >>

> >> Swap the reset, un-map steps sequence in sdhci_request_done().

> >>

> >> Changes since V1:

> >> - Added an empty line and fixed the comment style.

> >> - Retained the Acked-by signoff.

> >>

> >> Suggested-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>

> >> Signed-off-by: Pradeep P V K <pragalla@codeaurora.org>

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

>

> Hi Uffe,

> >

> > Seems like it might be a good idea to tag this for stable? I did that,

> > but awaiting for your confirmation.

> >

> Yes, this fix is applicable for all stable starting from 4.9 (n/a for

> 4.4).

> Kindly go ahead.

>

> > So, applied for next, thanks!

> >

> > Kind regards

> > Uffe

> >

> Thanks and Regards,

> Pradeep


Thanks for confirming, I have updated the stable tag.

Kind regards
Uffe

>

> >

> >> ---

> >>  drivers/mmc/host/sdhci.c | 60

> >> +++++++++++++++++++++++++-----------------------

> >>  1 file changed, 31 insertions(+), 29 deletions(-)

> >>

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

> >> index 646823d..130fd2d 100644

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

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

> >> @@ -2998,6 +2998,37 @@ static bool sdhci_request_done(struct

> >> sdhci_host *host)

> >>         }

> >>

> >>         /*

> >> +        * The controller needs a reset of internal state machines

> >> +        * upon error conditions.

> >> +        */

> >> +       if (sdhci_needs_reset(host, mrq)) {

> >> +               /*

> >> +                * Do not finish until command and data lines are

> >> available for

> >> +                * reset. Note there can only be one other mrq, so it

> >> cannot

> >> +                * also be in mrqs_done, otherwise host->cmd and

> >> host->data_cmd

> >> +                * would both be null.

> >> +                */

> >> +               if (host->cmd || host->data_cmd) {

> >> +                       spin_unlock_irqrestore(&host->lock, flags);

> >> +                       return true;

> >> +               }

> >> +

> >> +               /* Some controllers need this kick or reset won't work

> >> here */

> >> +               if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)

> >> +                       /* This is to force an update */

> >> +                       host->ops->set_clock(host, host->clock);

> >> +

> >> +               /*

> >> +                * Spec says we should do both at the same time, but

> >> Ricoh

> >> +                * controllers do not like that.

> >> +                */

> >> +               sdhci_do_reset(host, SDHCI_RESET_CMD);

> >> +               sdhci_do_reset(host, SDHCI_RESET_DATA);

> >> +

> >> +               host->pending_reset = false;

> >> +       }

> >> +

> >> +       /*

> >>          * Always unmap the data buffers if they were mapped by

> >>          * sdhci_prepare_data() whenever we finish with a request.

> >>          * This avoids leaking DMA mappings on error.

> >> @@ -3060,35 +3091,6 @@ static bool sdhci_request_done(struct

> >> sdhci_host *host)

> >>                 }

> >>         }

> >>

> >> -       /*

> >> -        * The controller needs a reset of internal state machines

> >> -        * upon error conditions.

> >> -        */

> >> -       if (sdhci_needs_reset(host, mrq)) {

> >> -               /*

> >> -                * Do not finish until command and data lines are

> >> available for

> >> -                * reset. Note there can only be one other mrq, so it

> >> cannot

> >> -                * also be in mrqs_done, otherwise host->cmd and

> >> host->data_cmd

> >> -                * would both be null.

> >> -                */

> >> -               if (host->cmd || host->data_cmd) {

> >> -                       spin_unlock_irqrestore(&host->lock, flags);

> >> -                       return true;

> >> -               }

> >> -

> >> -               /* Some controllers need this kick or reset won't work

> >> here */

> >> -               if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)

> >> -                       /* This is to force an update */

> >> -                       host->ops->set_clock(host, host->clock);

> >> -

> >> -               /* Spec says we should do both at the same time, but

> >> Ricoh

> >> -                  controllers do not like that. */

> >> -               sdhci_do_reset(host, SDHCI_RESET_CMD);

> >> -               sdhci_do_reset(host, SDHCI_RESET_DATA);

> >> -

> >> -               host->pending_reset = false;

> >> -       }

> >> -

> >>         host->mrqs_done[i] = NULL;

> >>

> >>         spin_unlock_irqrestore(&host->lock, flags);

> >> --

> >> 2.7.4

> >>
diff mbox series

Patch

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 646823d..130fd2d 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2998,6 +2998,37 @@  static bool sdhci_request_done(struct sdhci_host *host)
 	}
 
 	/*
+	 * The controller needs a reset of internal state machines
+	 * upon error conditions.
+	 */
+	if (sdhci_needs_reset(host, mrq)) {
+		/*
+		 * Do not finish until command and data lines are available for
+		 * reset. Note there can only be one other mrq, so it cannot
+		 * also be in mrqs_done, otherwise host->cmd and host->data_cmd
+		 * would both be null.
+		 */
+		if (host->cmd || host->data_cmd) {
+			spin_unlock_irqrestore(&host->lock, flags);
+			return true;
+		}
+
+		/* Some controllers need this kick or reset won't work here */
+		if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)
+			/* This is to force an update */
+			host->ops->set_clock(host, host->clock);
+
+		/*
+		 * Spec says we should do both at the same time, but Ricoh
+		 * controllers do not like that.
+		 */
+		sdhci_do_reset(host, SDHCI_RESET_CMD);
+		sdhci_do_reset(host, SDHCI_RESET_DATA);
+
+		host->pending_reset = false;
+	}
+
+	/*
 	 * Always unmap the data buffers if they were mapped by
 	 * sdhci_prepare_data() whenever we finish with a request.
 	 * This avoids leaking DMA mappings on error.
@@ -3060,35 +3091,6 @@  static bool sdhci_request_done(struct sdhci_host *host)
 		}
 	}
 
-	/*
-	 * The controller needs a reset of internal state machines
-	 * upon error conditions.
-	 */
-	if (sdhci_needs_reset(host, mrq)) {
-		/*
-		 * Do not finish until command and data lines are available for
-		 * reset. Note there can only be one other mrq, so it cannot
-		 * also be in mrqs_done, otherwise host->cmd and host->data_cmd
-		 * would both be null.
-		 */
-		if (host->cmd || host->data_cmd) {
-			spin_unlock_irqrestore(&host->lock, flags);
-			return true;
-		}
-
-		/* Some controllers need this kick or reset won't work here */
-		if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)
-			/* This is to force an update */
-			host->ops->set_clock(host, host->clock);
-
-		/* Spec says we should do both at the same time, but Ricoh
-		   controllers do not like that. */
-		sdhci_do_reset(host, SDHCI_RESET_CMD);
-		sdhci_do_reset(host, SDHCI_RESET_DATA);
-
-		host->pending_reset = false;
-	}
-
 	host->mrqs_done[i] = NULL;
 
 	spin_unlock_irqrestore(&host->lock, flags);