All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH V9 0/9] Add support for privileged mappings
@ 2017-01-06 13:28 ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse, pdaly, jgebben, joro, linux-kernel, pratikp, iommu,
	robin.murphy, tzeng, linux-arm-kernel, will.deacon, mitchelh,
	vinod.koul, dan.j.williams, linux
  Cc: sricharan

This series is a resend of the V5 that Mitch sent sometime back [2]
All the patches are the same and i have just rebased. Redid patch [3],
as it does not apply in this code base. Added a couple of more patches
[4], [5] from Robin for adding the privileged attributes to armv7s format
and arm-smmuv3 revert. Added a patch for passing in the privileged
attributes from arm32 dma-mapping apis as well.

The following patch to the ARM SMMU driver:

    commit d346180e70b91b3d5a1ae7e5603e65593d4622bc
    Author: Robin Murphy <robin.murphy@arm.com>
    Date:   Tue Jan 26 18:06:34 2016 +0000
    
        iommu/arm-smmu: Treat all device transactions as unprivileged

started forcing all SMMU transactions to come through as "unprivileged".
The rationale given was that:

  (1) There is no way in the IOMMU API to even request privileged
      mappings.

  (2) It's difficult to implement a DMA mapper that correctly models the
      ARM VMSAv8 behavior of unprivileged-writeable =>
      privileged-execute-never.

This series rectifies (1) by introducing an IOMMU API for privileged
mappings and implements it in io-pgtable-arm.

This series rectifies (2) by introducing a new dma attribute
(DMA_ATTR_PRIVILEGED) for users of the DMA API that need privileged
mappings which are inaccessible to lesser-privileged execution levels, and
implements it in the arm64 IOMMU DMA mapper.  The one known user (pl330.c)
is converted over to the new attribute.

Jordan and Jeremy can provide more info on the use case if needed, but the
high level is that it's a security feature to prevent attacks such as [1].

Note that, i tested this on arm64 with arm-smmuv2, short descriptor changes,
tested this on arm32 platform as well and do not have an platform to test
this with arm-smmuv3.

[1] https://github.com/robclark/kilroy
[2] https://lkml.org/lkml/2016/7/27/590
[3] https://patchwork.kernel.org/patch/9250493/
[4] http://www.linux-arm.org/git?p=linux-rm.git;a=commit;h=1291bd74f05d31da1dab3df02987cba5bd25849b
[5] http://www.linux-arm.org/git?p=linux-rm.git;a=commit;h=a79c1c6333f26849dba418cd92de26b60f5954f3

Changelog:
 v8..v9
    - Added additional comment in patch 1 and added tag for patch 6.

 v7..v8
    - Added a patch for passing in the privileged attributes from arm32
      dma-mapping apis as well.

 v6..v7
    - Added couple of more patches, picked up acks, updated commit log

 v5..v6
    - Rebased all the patches and redid 6/6 as it does not apply in
      this code base. 

 v4..v5
    - Simplified patch 4/6 (suggested by Robin Murphy).

 v3..v4
    - Rebased and reworked on linux next due to the dma attrs rework going
      on over there.  Patches changed: 3/6, 4/6, and 5/6.

 v2..v3
    - Incorporated feedback from Robin:
      * Various comments and re-wordings.
      * Use existing bit definitions for IOMMU_PRIV implementation
        in io-pgtable-arm.
      * Renamed and redocumented dma_direction_to_prot.
      * Don't worry about executability in new DMA attr.

 v1..v2
    - Added a new DMA attribute to make executable privileged mappings
      work, and use that in the pl330 driver (suggested by Will).

Jeremy Gebben (1):
  iommu/io-pgtable-arm: add support for the IOMMU_PRIV flag

Mitchel Humpherys (4):
  iommu: add IOMMU_PRIV attribute
  common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute
  arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED
  dmaengine: pl330: Make sure microcode is privileged

Robin Murphy (2):
  iommu/io-pgtable-arm-v7s: Add support for the IOMMU_PRIV flag
  Revert "iommu/arm-smmu: Set PRIVCFG in stage 1 STEs"

Sricharan R (2):
  arm/dma-mapping: Implement DMA_ATTR_PRIVILEGED
  iommu/arm-smmu: Set privileged attribute to 'default' instead of
    'unprivileged'

 Documentation/DMA-attributes.txt   | 10 +++++++
 arch/arm/mm/dma-mapping.c          | 60 +++++++++++++++++++-------------------
 arch/arm64/mm/dma-mapping.c        |  6 ++--
 drivers/dma/pl330.c                |  5 ++--
 drivers/iommu/arm-smmu-v3.c        |  7 +----
 drivers/iommu/arm-smmu.c           |  2 +-
 drivers/iommu/dma-iommu.c          | 12 ++++++--
 drivers/iommu/io-pgtable-arm-v7s.c |  6 +++-
 drivers/iommu/io-pgtable-arm.c     |  5 +++-
 include/linux/dma-iommu.h          |  3 +-
 include/linux/dma-mapping.h        |  7 +++++
 include/linux/iommu.h              |  7 +++++
 12 files changed, 82 insertions(+), 48 deletions(-)

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH V9 0/9] Add support for privileged mappings
@ 2017-01-06 13:28 ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse-sgV2jX0FEOL9JmXXK+q4OQ, pdaly-sgV2jX0FEOL9JmXXK+q4OQ,
	jgebben-sgV2jX0FEOL9JmXXK+q4OQ, joro-zLv9SwRftAIdnm+yROfE0A,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	pratikp-sgV2jX0FEOL9JmXXK+q4OQ,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	robin.murphy-5wv7dgnIgG8, tzeng-sgV2jX0FEOL9JmXXK+q4OQ,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	will.deacon-5wv7dgnIgG8, mitchelh-sgV2jX0FEOL9JmXXK+q4OQ,
	vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
	dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
	linux-I+IVW8TIWO2tmTQ+vhA3Yw

This series is a resend of the V5 that Mitch sent sometime back [2]
All the patches are the same and i have just rebased. Redid patch [3],
as it does not apply in this code base. Added a couple of more patches
[4], [5] from Robin for adding the privileged attributes to armv7s format
and arm-smmuv3 revert. Added a patch for passing in the privileged
attributes from arm32 dma-mapping apis as well.

The following patch to the ARM SMMU driver:

    commit d346180e70b91b3d5a1ae7e5603e65593d4622bc
    Author: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
    Date:   Tue Jan 26 18:06:34 2016 +0000
    
        iommu/arm-smmu: Treat all device transactions as unprivileged

started forcing all SMMU transactions to come through as "unprivileged".
The rationale given was that:

  (1) There is no way in the IOMMU API to even request privileged
      mappings.

  (2) It's difficult to implement a DMA mapper that correctly models the
      ARM VMSAv8 behavior of unprivileged-writeable =>
      privileged-execute-never.

This series rectifies (1) by introducing an IOMMU API for privileged
mappings and implements it in io-pgtable-arm.

This series rectifies (2) by introducing a new dma attribute
(DMA_ATTR_PRIVILEGED) for users of the DMA API that need privileged
mappings which are inaccessible to lesser-privileged execution levels, and
implements it in the arm64 IOMMU DMA mapper.  The one known user (pl330.c)
is converted over to the new attribute.

Jordan and Jeremy can provide more info on the use case if needed, but the
high level is that it's a security feature to prevent attacks such as [1].

Note that, i tested this on arm64 with arm-smmuv2, short descriptor changes,
tested this on arm32 platform as well and do not have an platform to test
this with arm-smmuv3.

[1] https://github.com/robclark/kilroy
[2] https://lkml.org/lkml/2016/7/27/590
[3] https://patchwork.kernel.org/patch/9250493/
[4] http://www.linux-arm.org/git?p=linux-rm.git;a=commit;h=1291bd74f05d31da1dab3df02987cba5bd25849b
[5] http://www.linux-arm.org/git?p=linux-rm.git;a=commit;h=a79c1c6333f26849dba418cd92de26b60f5954f3

Changelog:
 v8..v9
    - Added additional comment in patch 1 and added tag for patch 6.

 v7..v8
    - Added a patch for passing in the privileged attributes from arm32
      dma-mapping apis as well.

 v6..v7
    - Added couple of more patches, picked up acks, updated commit log

 v5..v6
    - Rebased all the patches and redid 6/6 as it does not apply in
      this code base. 

 v4..v5
    - Simplified patch 4/6 (suggested by Robin Murphy).

 v3..v4
    - Rebased and reworked on linux next due to the dma attrs rework going
      on over there.  Patches changed: 3/6, 4/6, and 5/6.

 v2..v3
    - Incorporated feedback from Robin:
      * Various comments and re-wordings.
      * Use existing bit definitions for IOMMU_PRIV implementation
        in io-pgtable-arm.
      * Renamed and redocumented dma_direction_to_prot.
      * Don't worry about executability in new DMA attr.

 v1..v2
    - Added a new DMA attribute to make executable privileged mappings
      work, and use that in the pl330 driver (suggested by Will).

Jeremy Gebben (1):
  iommu/io-pgtable-arm: add support for the IOMMU_PRIV flag

Mitchel Humpherys (4):
  iommu: add IOMMU_PRIV attribute
  common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute
  arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED
  dmaengine: pl330: Make sure microcode is privileged

Robin Murphy (2):
  iommu/io-pgtable-arm-v7s: Add support for the IOMMU_PRIV flag
  Revert "iommu/arm-smmu: Set PRIVCFG in stage 1 STEs"

Sricharan R (2):
  arm/dma-mapping: Implement DMA_ATTR_PRIVILEGED
  iommu/arm-smmu: Set privileged attribute to 'default' instead of
    'unprivileged'

 Documentation/DMA-attributes.txt   | 10 +++++++
 arch/arm/mm/dma-mapping.c          | 60 +++++++++++++++++++-------------------
 arch/arm64/mm/dma-mapping.c        |  6 ++--
 drivers/dma/pl330.c                |  5 ++--
 drivers/iommu/arm-smmu-v3.c        |  7 +----
 drivers/iommu/arm-smmu.c           |  2 +-
 drivers/iommu/dma-iommu.c          | 12 ++++++--
 drivers/iommu/io-pgtable-arm-v7s.c |  6 +++-
 drivers/iommu/io-pgtable-arm.c     |  5 +++-
 include/linux/dma-iommu.h          |  3 +-
 include/linux/dma-mapping.h        |  7 +++++
 include/linux/iommu.h              |  7 +++++
 12 files changed, 82 insertions(+), 48 deletions(-)

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH V9 0/9] Add support for privileged mappings
@ 2017-01-06 13:28 ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: linux-arm-kernel

This series is a resend of the V5 that Mitch sent sometime back [2]
All the patches are the same and i have just rebased. Redid patch [3],
as it does not apply in this code base. Added a couple of more patches
[4], [5] from Robin for adding the privileged attributes to armv7s format
and arm-smmuv3 revert. Added a patch for passing in the privileged
attributes from arm32 dma-mapping apis as well.

The following patch to the ARM SMMU driver:

    commit d346180e70b91b3d5a1ae7e5603e65593d4622bc
    Author: Robin Murphy <robin.murphy@arm.com>
    Date:   Tue Jan 26 18:06:34 2016 +0000
    
        iommu/arm-smmu: Treat all device transactions as unprivileged

started forcing all SMMU transactions to come through as "unprivileged".
The rationale given was that:

  (1) There is no way in the IOMMU API to even request privileged
      mappings.

  (2) It's difficult to implement a DMA mapper that correctly models the
      ARM VMSAv8 behavior of unprivileged-writeable =>
      privileged-execute-never.

This series rectifies (1) by introducing an IOMMU API for privileged
mappings and implements it in io-pgtable-arm.

This series rectifies (2) by introducing a new dma attribute
(DMA_ATTR_PRIVILEGED) for users of the DMA API that need privileged
mappings which are inaccessible to lesser-privileged execution levels, and
implements it in the arm64 IOMMU DMA mapper.  The one known user (pl330.c)
is converted over to the new attribute.

Jordan and Jeremy can provide more info on the use case if needed, but the
high level is that it's a security feature to prevent attacks such as [1].

Note that, i tested this on arm64 with arm-smmuv2, short descriptor changes,
tested this on arm32 platform as well and do not have an platform to test
this with arm-smmuv3.

[1] https://github.com/robclark/kilroy
[2] https://lkml.org/lkml/2016/7/27/590
[3] https://patchwork.kernel.org/patch/9250493/
[4] http://www.linux-arm.org/git?p=linux-rm.git;a=commit;h=1291bd74f05d31da1dab3df02987cba5bd25849b
[5] http://www.linux-arm.org/git?p=linux-rm.git;a=commit;h=a79c1c6333f26849dba418cd92de26b60f5954f3

Changelog:
 v8..v9
    - Added additional comment in patch 1 and added tag for patch 6.

 v7..v8
    - Added a patch for passing in the privileged attributes from arm32
      dma-mapping apis as well.

 v6..v7
    - Added couple of more patches, picked up acks, updated commit log

 v5..v6
    - Rebased all the patches and redid 6/6 as it does not apply in
      this code base. 

 v4..v5
    - Simplified patch 4/6 (suggested by Robin Murphy).

 v3..v4
    - Rebased and reworked on linux next due to the dma attrs rework going
      on over there.  Patches changed: 3/6, 4/6, and 5/6.

 v2..v3
    - Incorporated feedback from Robin:
      * Various comments and re-wordings.
      * Use existing bit definitions for IOMMU_PRIV implementation
        in io-pgtable-arm.
      * Renamed and redocumented dma_direction_to_prot.
      * Don't worry about executability in new DMA attr.

 v1..v2
    - Added a new DMA attribute to make executable privileged mappings
      work, and use that in the pl330 driver (suggested by Will).

Jeremy Gebben (1):
  iommu/io-pgtable-arm: add support for the IOMMU_PRIV flag

Mitchel Humpherys (4):
  iommu: add IOMMU_PRIV attribute
  common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute
  arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED
  dmaengine: pl330: Make sure microcode is privileged

Robin Murphy (2):
  iommu/io-pgtable-arm-v7s: Add support for the IOMMU_PRIV flag
  Revert "iommu/arm-smmu: Set PRIVCFG in stage 1 STEs"

Sricharan R (2):
  arm/dma-mapping: Implement DMA_ATTR_PRIVILEGED
  iommu/arm-smmu: Set privileged attribute to 'default' instead of
    'unprivileged'

 Documentation/DMA-attributes.txt   | 10 +++++++
 arch/arm/mm/dma-mapping.c          | 60 +++++++++++++++++++-------------------
 arch/arm64/mm/dma-mapping.c        |  6 ++--
 drivers/dma/pl330.c                |  5 ++--
 drivers/iommu/arm-smmu-v3.c        |  7 +----
 drivers/iommu/arm-smmu.c           |  2 +-
 drivers/iommu/dma-iommu.c          | 12 ++++++--
 drivers/iommu/io-pgtable-arm-v7s.c |  6 +++-
 drivers/iommu/io-pgtable-arm.c     |  5 +++-
 include/linux/dma-iommu.h          |  3 +-
 include/linux/dma-mapping.h        |  7 +++++
 include/linux/iommu.h              |  7 +++++
 12 files changed, 82 insertions(+), 48 deletions(-)

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH V9 1/9] iommu: add IOMMU_PRIV attribute
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse, pdaly, jgebben, joro, linux-kernel, pratikp, iommu,
	robin.murphy, tzeng, linux-arm-kernel, will.deacon, mitchelh,
	vinod.koul, dan.j.williams, linux
  Cc: sricharan

From: Mitchel Humpherys <mitchelh@codeaurora.org>

Add the IOMMU_PRIV attribute, which is used to indicate privileged
mappings.

Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Acked-by: Will Deacon <will.deacon@arm.com>
---
 include/linux/iommu.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 0ff5111..69e2417 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -31,6 +31,13 @@
 #define IOMMU_CACHE	(1 << 2) /* DMA cache coherency */
 #define IOMMU_NOEXEC	(1 << 3)
 #define IOMMU_MMIO	(1 << 4) /* e.g. things like MSI doorbells */
+/*
+ * This is to make the IOMMU API setup privileged
+ * mapppings accessible by the master only at higher
+ * privileged execution level and inaccessible at
+ * less privileged levels.
+ */
+#define IOMMU_PRIV	(1 << 5)
 
 struct iommu_ops;
 struct iommu_group;
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 1/9] iommu: add IOMMU_PRIV attribute
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse-sgV2jX0FEOL9JmXXK+q4OQ, pdaly-sgV2jX0FEOL9JmXXK+q4OQ,
	jgebben-sgV2jX0FEOL9JmXXK+q4OQ, joro-zLv9SwRftAIdnm+yROfE0A,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	pratikp-sgV2jX0FEOL9JmXXK+q4OQ,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	robin.murphy-5wv7dgnIgG8, tzeng-sgV2jX0FEOL9JmXXK+q4OQ,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	will.deacon-5wv7dgnIgG8, mitchelh-sgV2jX0FEOL9JmXXK+q4OQ,
	vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
	dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
	linux-I+IVW8TIWO2tmTQ+vhA3Yw

From: Mitchel Humpherys <mitchelh-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

Add the IOMMU_PRIV attribute, which is used to indicate privileged
mappings.

Reviewed-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Tested-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Signed-off-by: Mitchel Humpherys <mitchelh-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
Acked-by: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
---
 include/linux/iommu.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 0ff5111..69e2417 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -31,6 +31,13 @@
 #define IOMMU_CACHE	(1 << 2) /* DMA cache coherency */
 #define IOMMU_NOEXEC	(1 << 3)
 #define IOMMU_MMIO	(1 << 4) /* e.g. things like MSI doorbells */
+/*
+ * This is to make the IOMMU API setup privileged
+ * mapppings accessible by the master only at higher
+ * privileged execution level and inaccessible at
+ * less privileged levels.
+ */
+#define IOMMU_PRIV	(1 << 5)
 
 struct iommu_ops;
 struct iommu_group;
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 1/9] iommu: add IOMMU_PRIV attribute
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: linux-arm-kernel

From: Mitchel Humpherys <mitchelh@codeaurora.org>

Add the IOMMU_PRIV attribute, which is used to indicate privileged
mappings.

Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Acked-by: Will Deacon <will.deacon@arm.com>
---
 include/linux/iommu.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 0ff5111..69e2417 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -31,6 +31,13 @@
 #define IOMMU_CACHE	(1 << 2) /* DMA cache coherency */
 #define IOMMU_NOEXEC	(1 << 3)
 #define IOMMU_MMIO	(1 << 4) /* e.g. things like MSI doorbells */
+/*
+ * This is to make the IOMMU API setup privileged
+ * mapppings accessible by the master only@higher
+ * privileged execution level and inaccessible at
+ * less privileged levels.
+ */
+#define IOMMU_PRIV	(1 << 5)
 
 struct iommu_ops;
 struct iommu_group;
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 2/9] iommu/io-pgtable-arm: add support for the IOMMU_PRIV flag
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse, pdaly, jgebben, joro, linux-kernel, pratikp, iommu,
	robin.murphy, tzeng, linux-arm-kernel, will.deacon, mitchelh,
	vinod.koul, dan.j.williams, linux
  Cc: sricharan

From: Jeremy Gebben <jgebben@codeaurora.org>

Allow the creation of privileged mode mappings, for stage 1 only.

Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
---
 drivers/iommu/io-pgtable-arm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index a40ce34..feacc54 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -350,11 +350,14 @@ static arm_lpae_iopte arm_lpae_prot_to_pte(struct arm_lpae_io_pgtable *data,
 
 	if (data->iop.fmt == ARM_64_LPAE_S1 ||
 	    data->iop.fmt == ARM_32_LPAE_S1) {
-		pte = ARM_LPAE_PTE_AP_UNPRIV | ARM_LPAE_PTE_nG;
+		pte = ARM_LPAE_PTE_nG;
 
 		if (!(prot & IOMMU_WRITE) && (prot & IOMMU_READ))
 			pte |= ARM_LPAE_PTE_AP_RDONLY;
 
+		if (!(prot & IOMMU_PRIV))
+			pte |= ARM_LPAE_PTE_AP_UNPRIV;
+
 		if (prot & IOMMU_MMIO)
 			pte |= (ARM_LPAE_MAIR_ATTR_IDX_DEV
 				<< ARM_LPAE_PTE_ATTRINDX_SHIFT);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 2/9] iommu/io-pgtable-arm: add support for the IOMMU_PRIV flag
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse-sgV2jX0FEOL9JmXXK+q4OQ, pdaly-sgV2jX0FEOL9JmXXK+q4OQ,
	jgebben-sgV2jX0FEOL9JmXXK+q4OQ, joro-zLv9SwRftAIdnm+yROfE0A,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	pratikp-sgV2jX0FEOL9JmXXK+q4OQ,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	robin.murphy-5wv7dgnIgG8, tzeng-sgV2jX0FEOL9JmXXK+q4OQ,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	will.deacon-5wv7dgnIgG8, mitchelh-sgV2jX0FEOL9JmXXK+q4OQ,
	vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
	dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
	linux-I+IVW8TIWO2tmTQ+vhA3Yw

From: Jeremy Gebben <jgebben-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

Allow the creation of privileged mode mappings, for stage 1 only.

Reviewed-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Tested-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Acked-by: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
Signed-off-by: Jeremy Gebben <jgebben-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 drivers/iommu/io-pgtable-arm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index a40ce34..feacc54 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -350,11 +350,14 @@ static arm_lpae_iopte arm_lpae_prot_to_pte(struct arm_lpae_io_pgtable *data,
 
 	if (data->iop.fmt == ARM_64_LPAE_S1 ||
 	    data->iop.fmt == ARM_32_LPAE_S1) {
-		pte = ARM_LPAE_PTE_AP_UNPRIV | ARM_LPAE_PTE_nG;
+		pte = ARM_LPAE_PTE_nG;
 
 		if (!(prot & IOMMU_WRITE) && (prot & IOMMU_READ))
 			pte |= ARM_LPAE_PTE_AP_RDONLY;
 
+		if (!(prot & IOMMU_PRIV))
+			pte |= ARM_LPAE_PTE_AP_UNPRIV;
+
 		if (prot & IOMMU_MMIO)
 			pte |= (ARM_LPAE_MAIR_ATTR_IDX_DEV
 				<< ARM_LPAE_PTE_ATTRINDX_SHIFT);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 2/9] iommu/io-pgtable-arm: add support for the IOMMU_PRIV flag
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: linux-arm-kernel

From: Jeremy Gebben <jgebben@codeaurora.org>

Allow the creation of privileged mode mappings, for stage 1 only.

Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
---
 drivers/iommu/io-pgtable-arm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index a40ce34..feacc54 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -350,11 +350,14 @@ static arm_lpae_iopte arm_lpae_prot_to_pte(struct arm_lpae_io_pgtable *data,
 
 	if (data->iop.fmt == ARM_64_LPAE_S1 ||
 	    data->iop.fmt == ARM_32_LPAE_S1) {
-		pte = ARM_LPAE_PTE_AP_UNPRIV | ARM_LPAE_PTE_nG;
+		pte = ARM_LPAE_PTE_nG;
 
 		if (!(prot & IOMMU_WRITE) && (prot & IOMMU_READ))
 			pte |= ARM_LPAE_PTE_AP_RDONLY;
 
+		if (!(prot & IOMMU_PRIV))
+			pte |= ARM_LPAE_PTE_AP_UNPRIV;
+
 		if (prot & IOMMU_MMIO)
 			pte |= (ARM_LPAE_MAIR_ATTR_IDX_DEV
 				<< ARM_LPAE_PTE_ATTRINDX_SHIFT);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 3/9] iommu/io-pgtable-arm-v7s: Add support for the IOMMU_PRIV flag
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse, pdaly, jgebben, joro, linux-kernel, pratikp, iommu,
	robin.murphy, tzeng, linux-arm-kernel, will.deacon, mitchelh,
	vinod.koul, dan.j.williams, linux
  Cc: sricharan

From: Robin Murphy <robin.murphy@arm.com>

The short-descriptor format also allows privileged-only mappings, so
let's wire it up.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Sricharan R <sricharan@codeaurora.org>
---
 drivers/iommu/io-pgtable-arm-v7s.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index 0769276..1c049e2 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -265,7 +265,9 @@ static arm_v7s_iopte arm_v7s_prot_to_pte(int prot, int lvl,
 	if (!(prot & IOMMU_MMIO))
 		pte |= ARM_V7S_ATTR_TEX(1);
 	if (ap) {
-		pte |= ARM_V7S_PTE_AF | ARM_V7S_PTE_AP_UNPRIV;
+		pte |= ARM_V7S_PTE_AF;
+		if (!(prot & IOMMU_PRIV))
+			pte |= ARM_V7S_PTE_AP_UNPRIV;
 		if (!(prot & IOMMU_WRITE))
 			pte |= ARM_V7S_PTE_AP_RDONLY;
 	}
@@ -288,6 +290,8 @@ static int arm_v7s_pte_to_prot(arm_v7s_iopte pte, int lvl)
 
 	if (!(attr & ARM_V7S_PTE_AP_RDONLY))
 		prot |= IOMMU_WRITE;
+	if (!(attr & ARM_V7S_PTE_AP_UNPRIV))
+		prot |= IOMMU_PRIV;
 	if ((attr & (ARM_V7S_TEX_MASK << ARM_V7S_TEX_SHIFT)) == 0)
 		prot |= IOMMU_MMIO;
 	else if (pte & ARM_V7S_ATTR_C)
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 3/9] iommu/io-pgtable-arm-v7s: Add support for the IOMMU_PRIV flag
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse-sgV2jX0FEOL9JmXXK+q4OQ, pdaly-sgV2jX0FEOL9JmXXK+q4OQ,
	jgebben-sgV2jX0FEOL9JmXXK+q4OQ, joro-zLv9SwRftAIdnm+yROfE0A,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	pratikp-sgV2jX0FEOL9JmXXK+q4OQ,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	robin.murphy-5wv7dgnIgG8, tzeng-sgV2jX0FEOL9JmXXK+q4OQ,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	will.deacon-5wv7dgnIgG8, mitchelh-sgV2jX0FEOL9JmXXK+q4OQ,
	vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
	dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
	linux-I+IVW8TIWO2tmTQ+vhA3Yw

From: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>

The short-descriptor format also allows privileged-only mappings, so
let's wire it up.

Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Tested-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 drivers/iommu/io-pgtable-arm-v7s.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index 0769276..1c049e2 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -265,7 +265,9 @@ static arm_v7s_iopte arm_v7s_prot_to_pte(int prot, int lvl,
 	if (!(prot & IOMMU_MMIO))
 		pte |= ARM_V7S_ATTR_TEX(1);
 	if (ap) {
-		pte |= ARM_V7S_PTE_AF | ARM_V7S_PTE_AP_UNPRIV;
+		pte |= ARM_V7S_PTE_AF;
+		if (!(prot & IOMMU_PRIV))
+			pte |= ARM_V7S_PTE_AP_UNPRIV;
 		if (!(prot & IOMMU_WRITE))
 			pte |= ARM_V7S_PTE_AP_RDONLY;
 	}
@@ -288,6 +290,8 @@ static int arm_v7s_pte_to_prot(arm_v7s_iopte pte, int lvl)
 
 	if (!(attr & ARM_V7S_PTE_AP_RDONLY))
 		prot |= IOMMU_WRITE;
+	if (!(attr & ARM_V7S_PTE_AP_UNPRIV))
+		prot |= IOMMU_PRIV;
 	if ((attr & (ARM_V7S_TEX_MASK << ARM_V7S_TEX_SHIFT)) == 0)
 		prot |= IOMMU_MMIO;
 	else if (pte & ARM_V7S_ATTR_C)
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 3/9] iommu/io-pgtable-arm-v7s: Add support for the IOMMU_PRIV flag
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: linux-arm-kernel

From: Robin Murphy <robin.murphy@arm.com>

The short-descriptor format also allows privileged-only mappings, so
let's wire it up.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Sricharan R <sricharan@codeaurora.org>
---
 drivers/iommu/io-pgtable-arm-v7s.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index 0769276..1c049e2 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -265,7 +265,9 @@ static arm_v7s_iopte arm_v7s_prot_to_pte(int prot, int lvl,
 	if (!(prot & IOMMU_MMIO))
 		pte |= ARM_V7S_ATTR_TEX(1);
 	if (ap) {
-		pte |= ARM_V7S_PTE_AF | ARM_V7S_PTE_AP_UNPRIV;
+		pte |= ARM_V7S_PTE_AF;
+		if (!(prot & IOMMU_PRIV))
+			pte |= ARM_V7S_PTE_AP_UNPRIV;
 		if (!(prot & IOMMU_WRITE))
 			pte |= ARM_V7S_PTE_AP_RDONLY;
 	}
@@ -288,6 +290,8 @@ static int arm_v7s_pte_to_prot(arm_v7s_iopte pte, int lvl)
 
 	if (!(attr & ARM_V7S_PTE_AP_RDONLY))
 		prot |= IOMMU_WRITE;
+	if (!(attr & ARM_V7S_PTE_AP_UNPRIV))
+		prot |= IOMMU_PRIV;
 	if ((attr & (ARM_V7S_TEX_MASK << ARM_V7S_TEX_SHIFT)) == 0)
 		prot |= IOMMU_MMIO;
 	else if (pte & ARM_V7S_ATTR_C)
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 4/9] common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse, pdaly, jgebben, joro, linux-kernel, pratikp, iommu,
	robin.murphy, tzeng, linux-arm-kernel, will.deacon, mitchelh,
	vinod.koul, dan.j.williams, linux
  Cc: sricharan

From: Mitchel Humpherys <mitchelh@codeaurora.org>

This patch adds the DMA_ATTR_PRIVILEGED attribute to the DMA-mapping
subsystem.

Some advanced peripherals such as remote processors and GPUs perform
accesses to DMA buffers in both privileged "supervisor" and unprivileged
"user" modes.  This attribute is used to indicate to the DMA-mapping
subsystem that the buffer is fully accessible at the elevated privilege
level (and ideally inaccessible or at least read-only at the
lesser-privileged levels).

Cc: linux-doc@vger.kernel.org
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
---
 Documentation/DMA-attributes.txt | 10 ++++++++++
 include/linux/dma-mapping.h      |  7 +++++++
 2 files changed, 17 insertions(+)

diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt
index 98bf7ac..44c6bc4 100644
--- a/Documentation/DMA-attributes.txt
+++ b/Documentation/DMA-attributes.txt
@@ -143,3 +143,13 @@ So, this provides a way for drivers to avoid those error messages on calls
 where allocation failures are not a problem, and shouldn't bother the logs.
 
 NOTE: At the moment DMA_ATTR_NO_WARN is only implemented on PowerPC.
+
+DMA_ATTR_PRIVILEGED
+------------------------------
+
+Some advanced peripherals such as remote processors and GPUs perform
+accesses to DMA buffers in both privileged "supervisor" and unprivileged
+"user" modes.  This attribute is used to indicate to the DMA-mapping
+subsystem that the buffer is fully accessible at the elevated privilege
+level (and ideally inaccessible or at least read-only at the
+lesser-privileged levels).
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 10c5a17b1..c24721a 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -63,6 +63,13 @@
 #define DMA_ATTR_NO_WARN	(1UL << 8)
 
 /*
+ * DMA_ATTR_PRIVILEGED: used to indicate that the buffer is fully
+ * accessible at an elevated privilege level (and ideally inaccessible or
+ * at least read-only at lesser-privileged levels).
+ */
+#define DMA_ATTR_PRIVILEGED		(1UL << 9)
+
+/*
  * A dma_addr_t can hold any valid DMA or bus address for the platform.
  * It can be given to a device to use as a DMA source or target.  A CPU cannot
  * reference a dma_addr_t directly because there may be translation between
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 4/9] common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse-sgV2jX0FEOL9JmXXK+q4OQ, pdaly-sgV2jX0FEOL9JmXXK+q4OQ,
	jgebben-sgV2jX0FEOL9JmXXK+q4OQ, joro-zLv9SwRftAIdnm+yROfE0A,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	pratikp-sgV2jX0FEOL9JmXXK+q4OQ,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	robin.murphy-5wv7dgnIgG8, tzeng-sgV2jX0FEOL9JmXXK+q4OQ,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	will.deacon-5wv7dgnIgG8, mitchelh-sgV2jX0FEOL9JmXXK+q4OQ,
	vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
	dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
	linux-I+IVW8TIWO2tmTQ+vhA3Yw

From: Mitchel Humpherys <mitchelh-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

This patch adds the DMA_ATTR_PRIVILEGED attribute to the DMA-mapping
subsystem.

Some advanced peripherals such as remote processors and GPUs perform
accesses to DMA buffers in both privileged "supervisor" and unprivileged
"user" modes.  This attribute is used to indicate to the DMA-mapping
subsystem that the buffer is fully accessible at the elevated privilege
level (and ideally inaccessible or at least read-only at the
lesser-privileged levels).

Cc: linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Reviewed-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Tested-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Acked-by: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
Signed-off-by: Mitchel Humpherys <mitchelh-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 Documentation/DMA-attributes.txt | 10 ++++++++++
 include/linux/dma-mapping.h      |  7 +++++++
 2 files changed, 17 insertions(+)

diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt
index 98bf7ac..44c6bc4 100644
--- a/Documentation/DMA-attributes.txt
+++ b/Documentation/DMA-attributes.txt
@@ -143,3 +143,13 @@ So, this provides a way for drivers to avoid those error messages on calls
 where allocation failures are not a problem, and shouldn't bother the logs.
 
 NOTE: At the moment DMA_ATTR_NO_WARN is only implemented on PowerPC.
+
+DMA_ATTR_PRIVILEGED
+------------------------------
+
+Some advanced peripherals such as remote processors and GPUs perform
+accesses to DMA buffers in both privileged "supervisor" and unprivileged
+"user" modes.  This attribute is used to indicate to the DMA-mapping
+subsystem that the buffer is fully accessible at the elevated privilege
+level (and ideally inaccessible or at least read-only at the
+lesser-privileged levels).
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 10c5a17b1..c24721a 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -63,6 +63,13 @@
 #define DMA_ATTR_NO_WARN	(1UL << 8)
 
 /*
+ * DMA_ATTR_PRIVILEGED: used to indicate that the buffer is fully
+ * accessible at an elevated privilege level (and ideally inaccessible or
+ * at least read-only at lesser-privileged levels).
+ */
+#define DMA_ATTR_PRIVILEGED		(1UL << 9)
+
+/*
  * A dma_addr_t can hold any valid DMA or bus address for the platform.
  * It can be given to a device to use as a DMA source or target.  A CPU cannot
  * reference a dma_addr_t directly because there may be translation between
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 4/9] common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: linux-arm-kernel

From: Mitchel Humpherys <mitchelh@codeaurora.org>

This patch adds the DMA_ATTR_PRIVILEGED attribute to the DMA-mapping
subsystem.

Some advanced peripherals such as remote processors and GPUs perform
accesses to DMA buffers in both privileged "supervisor" and unprivileged
"user" modes.  This attribute is used to indicate to the DMA-mapping
subsystem that the buffer is fully accessible at the elevated privilege
level (and ideally inaccessible or at least read-only at the
lesser-privileged levels).

Cc: linux-doc at vger.kernel.org
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
---
 Documentation/DMA-attributes.txt | 10 ++++++++++
 include/linux/dma-mapping.h      |  7 +++++++
 2 files changed, 17 insertions(+)

diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt
index 98bf7ac..44c6bc4 100644
--- a/Documentation/DMA-attributes.txt
+++ b/Documentation/DMA-attributes.txt
@@ -143,3 +143,13 @@ So, this provides a way for drivers to avoid those error messages on calls
 where allocation failures are not a problem, and shouldn't bother the logs.
 
 NOTE: At the moment DMA_ATTR_NO_WARN is only implemented on PowerPC.
+
+DMA_ATTR_PRIVILEGED
+------------------------------
+
+Some advanced peripherals such as remote processors and GPUs perform
+accesses to DMA buffers in both privileged "supervisor" and unprivileged
+"user" modes.  This attribute is used to indicate to the DMA-mapping
+subsystem that the buffer is fully accessible at the elevated privilege
+level (and ideally inaccessible or at least read-only at the
+lesser-privileged levels).
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 10c5a17b1..c24721a 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -63,6 +63,13 @@
 #define DMA_ATTR_NO_WARN	(1UL << 8)
 
 /*
+ * DMA_ATTR_PRIVILEGED: used to indicate that the buffer is fully
+ * accessible at an elevated privilege level (and ideally inaccessible or
+ * at least read-only@lesser-privileged levels).
+ */
+#define DMA_ATTR_PRIVILEGED		(1UL << 9)
+
+/*
  * A dma_addr_t can hold any valid DMA or bus address for the platform.
  * It can be given to a device to use as a DMA source or target.  A CPU cannot
  * reference a dma_addr_t directly because there may be translation between
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 5/9] arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse, pdaly, jgebben, joro, linux-kernel, pratikp, iommu,
	robin.murphy, tzeng, linux-arm-kernel, will.deacon, mitchelh,
	vinod.koul, dan.j.williams, linux
  Cc: sricharan

From: Mitchel Humpherys <mitchelh@codeaurora.org>

The newly added DMA_ATTR_PRIVILEGED is useful for creating mappings that
are only accessible to privileged DMA engines.  Implement it in
dma-iommu.c so that the ARM64 DMA IOMMU mapper can make use of it.

Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
---
 arch/arm64/mm/dma-mapping.c |  6 +++---
 drivers/iommu/dma-iommu.c   | 12 +++++++++---
 include/linux/dma-iommu.h   |  3 ++-
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 290a84f..49c6f75 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -557,7 +557,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size,
 				 unsigned long attrs)
 {
 	bool coherent = is_device_dma_coherent(dev);
-	int ioprot = dma_direction_to_prot(DMA_BIDIRECTIONAL, coherent);
+	int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
 	size_t iosize = size;
 	void *addr;
 
@@ -711,7 +711,7 @@ static dma_addr_t __iommu_map_page(struct device *dev, struct page *page,
 				   unsigned long attrs)
 {
 	bool coherent = is_device_dma_coherent(dev);
-	int prot = dma_direction_to_prot(dir, coherent);
+	int prot = dma_info_to_prot(dir, coherent, attrs);
 	dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot);
 
 	if (!iommu_dma_mapping_error(dev, dev_addr) &&
@@ -769,7 +769,7 @@ static int __iommu_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
 		__iommu_sync_sg_for_device(dev, sgl, nelems, dir);
 
 	return iommu_dma_map_sg(dev, sgl, nelems,
-			dma_direction_to_prot(dir, coherent));
+				dma_info_to_prot(dir, coherent, attrs));
 }
 
 static void __iommu_unmap_sg_attrs(struct device *dev,
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 2db0d64..3006eee 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -181,16 +181,22 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 EXPORT_SYMBOL(iommu_dma_init_domain);
 
 /**
- * dma_direction_to_prot - Translate DMA API directions to IOMMU API page flags
+ * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API
+ *                    page flags.
  * @dir: Direction of DMA transfer
  * @coherent: Is the DMA master cache-coherent?
+ * @attrs: DMA attributes for the mapping
  *
  * Return: corresponding IOMMU API page protection flags
  */
-int dma_direction_to_prot(enum dma_data_direction dir, bool coherent)
+int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
+		     unsigned long attrs)
 {
 	int prot = coherent ? IOMMU_CACHE : 0;
 
+	if (attrs & DMA_ATTR_PRIVILEGED)
+		prot |= IOMMU_PRIV;
+
 	switch (dir) {
 	case DMA_BIDIRECTIONAL:
 		return prot | IOMMU_READ | IOMMU_WRITE;
@@ -633,7 +639,7 @@ dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
 		size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
 	return __iommu_dma_map(dev, phys, size,
-			dma_direction_to_prot(dir, false) | IOMMU_MMIO);
+			dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO);
 }
 
 void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 7f7e9a7..c5511e1 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -34,7 +34,8 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 		u64 size, struct device *dev);
 
 /* General helpers for DMA-API <-> IOMMU-API interaction */
-int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);
+int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
+		     unsigned long attrs);
 
 /*
  * These implement the bulk of the relevant DMA mapping callbacks, but require
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 5/9] arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse-sgV2jX0FEOL9JmXXK+q4OQ, pdaly-sgV2jX0FEOL9JmXXK+q4OQ,
	jgebben-sgV2jX0FEOL9JmXXK+q4OQ, joro-zLv9SwRftAIdnm+yROfE0A,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	pratikp-sgV2jX0FEOL9JmXXK+q4OQ,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	robin.murphy-5wv7dgnIgG8, tzeng-sgV2jX0FEOL9JmXXK+q4OQ,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	will.deacon-5wv7dgnIgG8, mitchelh-sgV2jX0FEOL9JmXXK+q4OQ,
	vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
	dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
	linux-I+IVW8TIWO2tmTQ+vhA3Yw

From: Mitchel Humpherys <mitchelh-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

The newly added DMA_ATTR_PRIVILEGED is useful for creating mappings that
are only accessible to privileged DMA engines.  Implement it in
dma-iommu.c so that the ARM64 DMA IOMMU mapper can make use of it.

Reviewed-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Tested-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Acked-by: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
Signed-off-by: Mitchel Humpherys <mitchelh-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 arch/arm64/mm/dma-mapping.c |  6 +++---
 drivers/iommu/dma-iommu.c   | 12 +++++++++---
 include/linux/dma-iommu.h   |  3 ++-
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 290a84f..49c6f75 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -557,7 +557,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size,
 				 unsigned long attrs)
 {
 	bool coherent = is_device_dma_coherent(dev);
-	int ioprot = dma_direction_to_prot(DMA_BIDIRECTIONAL, coherent);
+	int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
 	size_t iosize = size;
 	void *addr;
 
@@ -711,7 +711,7 @@ static dma_addr_t __iommu_map_page(struct device *dev, struct page *page,
 				   unsigned long attrs)
 {
 	bool coherent = is_device_dma_coherent(dev);
-	int prot = dma_direction_to_prot(dir, coherent);
+	int prot = dma_info_to_prot(dir, coherent, attrs);
 	dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot);
 
 	if (!iommu_dma_mapping_error(dev, dev_addr) &&
@@ -769,7 +769,7 @@ static int __iommu_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
 		__iommu_sync_sg_for_device(dev, sgl, nelems, dir);
 
 	return iommu_dma_map_sg(dev, sgl, nelems,
-			dma_direction_to_prot(dir, coherent));
+				dma_info_to_prot(dir, coherent, attrs));
 }
 
 static void __iommu_unmap_sg_attrs(struct device *dev,
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 2db0d64..3006eee 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -181,16 +181,22 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 EXPORT_SYMBOL(iommu_dma_init_domain);
 
 /**
- * dma_direction_to_prot - Translate DMA API directions to IOMMU API page flags
+ * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API
+ *                    page flags.
  * @dir: Direction of DMA transfer
  * @coherent: Is the DMA master cache-coherent?
+ * @attrs: DMA attributes for the mapping
  *
  * Return: corresponding IOMMU API page protection flags
  */
-int dma_direction_to_prot(enum dma_data_direction dir, bool coherent)
+int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
+		     unsigned long attrs)
 {
 	int prot = coherent ? IOMMU_CACHE : 0;
 
+	if (attrs & DMA_ATTR_PRIVILEGED)
+		prot |= IOMMU_PRIV;
+
 	switch (dir) {
 	case DMA_BIDIRECTIONAL:
 		return prot | IOMMU_READ | IOMMU_WRITE;
@@ -633,7 +639,7 @@ dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
 		size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
 	return __iommu_dma_map(dev, phys, size,
-			dma_direction_to_prot(dir, false) | IOMMU_MMIO);
+			dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO);
 }
 
 void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 7f7e9a7..c5511e1 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -34,7 +34,8 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 		u64 size, struct device *dev);
 
 /* General helpers for DMA-API <-> IOMMU-API interaction */
-int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);
+int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
+		     unsigned long attrs);
 
 /*
  * These implement the bulk of the relevant DMA mapping callbacks, but require
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 5/9] arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: linux-arm-kernel

From: Mitchel Humpherys <mitchelh@codeaurora.org>

The newly added DMA_ATTR_PRIVILEGED is useful for creating mappings that
are only accessible to privileged DMA engines.  Implement it in
dma-iommu.c so that the ARM64 DMA IOMMU mapper can make use of it.

Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
---
 arch/arm64/mm/dma-mapping.c |  6 +++---
 drivers/iommu/dma-iommu.c   | 12 +++++++++---
 include/linux/dma-iommu.h   |  3 ++-
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 290a84f..49c6f75 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -557,7 +557,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size,
 				 unsigned long attrs)
 {
 	bool coherent = is_device_dma_coherent(dev);
-	int ioprot = dma_direction_to_prot(DMA_BIDIRECTIONAL, coherent);
+	int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
 	size_t iosize = size;
 	void *addr;
 
@@ -711,7 +711,7 @@ static dma_addr_t __iommu_map_page(struct device *dev, struct page *page,
 				   unsigned long attrs)
 {
 	bool coherent = is_device_dma_coherent(dev);
-	int prot = dma_direction_to_prot(dir, coherent);
+	int prot = dma_info_to_prot(dir, coherent, attrs);
 	dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot);
 
 	if (!iommu_dma_mapping_error(dev, dev_addr) &&
@@ -769,7 +769,7 @@ static int __iommu_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
 		__iommu_sync_sg_for_device(dev, sgl, nelems, dir);
 
 	return iommu_dma_map_sg(dev, sgl, nelems,
-			dma_direction_to_prot(dir, coherent));
+				dma_info_to_prot(dir, coherent, attrs));
 }
 
 static void __iommu_unmap_sg_attrs(struct device *dev,
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 2db0d64..3006eee 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -181,16 +181,22 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 EXPORT_SYMBOL(iommu_dma_init_domain);
 
 /**
- * dma_direction_to_prot - Translate DMA API directions to IOMMU API page flags
+ * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API
+ *                    page flags.
  * @dir: Direction of DMA transfer
  * @coherent: Is the DMA master cache-coherent?
+ * @attrs: DMA attributes for the mapping
  *
  * Return: corresponding IOMMU API page protection flags
  */
-int dma_direction_to_prot(enum dma_data_direction dir, bool coherent)
+int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
+		     unsigned long attrs)
 {
 	int prot = coherent ? IOMMU_CACHE : 0;
 
+	if (attrs & DMA_ATTR_PRIVILEGED)
+		prot |= IOMMU_PRIV;
+
 	switch (dir) {
 	case DMA_BIDIRECTIONAL:
 		return prot | IOMMU_READ | IOMMU_WRITE;
@@ -633,7 +639,7 @@ dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
 		size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
 	return __iommu_dma_map(dev, phys, size,
-			dma_direction_to_prot(dir, false) | IOMMU_MMIO);
+			dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO);
 }
 
 void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 7f7e9a7..c5511e1 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -34,7 +34,8 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 		u64 size, struct device *dev);
 
 /* General helpers for DMA-API <-> IOMMU-API interaction */
-int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);
+int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
+		     unsigned long attrs);
 
 /*
  * These implement the bulk of the relevant DMA mapping callbacks, but require
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 6/9] arm/dma-mapping: Implement DMA_ATTR_PRIVILEGED
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse, pdaly, jgebben, joro, linux-kernel, pratikp, iommu,
	robin.murphy, tzeng, linux-arm-kernel, will.deacon, mitchelh,
	vinod.koul, dan.j.williams, linux
  Cc: sricharan

The newly added DMA_ATTR_PRIVILEGED is useful for creating mappings that
are only accessible to privileged DMA engines.  Adding it to the
arm dma-mapping.c so that the ARM32 DMA IOMMU mapper can make use of it.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm/mm/dma-mapping.c | 60 +++++++++++++++++++++++------------------------
 1 file changed, 30 insertions(+), 30 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index ab77100..82d3e79 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1171,6 +1171,25 @@ static int __init dma_debug_do_init(void)
 
 #ifdef CONFIG_ARM_DMA_USE_IOMMU
 
+static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs)
+{
+	int prot = 0;
+
+	if (attrs & DMA_ATTR_PRIVILEGED)
+		prot |= IOMMU_PRIV;
+
+	switch (dir) {
+	case DMA_BIDIRECTIONAL:
+		return prot | IOMMU_READ | IOMMU_WRITE;
+	case DMA_TO_DEVICE:
+		return prot | IOMMU_READ;
+	case DMA_FROM_DEVICE:
+		return prot | IOMMU_WRITE;
+	default:
+		return prot;
+	}
+}
+
 /* IOMMU */
 
 static int extend_iommu_mapping(struct dma_iommu_mapping *mapping);
@@ -1394,7 +1413,8 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages,
  * Create a mapping in device IO address space for specified pages
  */
 static dma_addr_t
-__iommu_create_mapping(struct device *dev, struct page **pages, size_t size)
+__iommu_create_mapping(struct device *dev, struct page **pages, size_t size,
+		       unsigned long attrs)
 {
 	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
 	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
@@ -1419,7 +1439,7 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages,
 
 		len = (j - i) << PAGE_SHIFT;
 		ret = iommu_map(mapping->domain, iova, phys, len,
-				IOMMU_READ|IOMMU_WRITE);
+				__dma_info_to_prot(DMA_BIDIRECTIONAL, attrs));
 		if (ret < 0)
 			goto fail;
 		iova += len;
@@ -1476,7 +1496,8 @@ static struct page **__iommu_get_pages(void *cpu_addr, unsigned long attrs)
 }
 
 static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,
-				  dma_addr_t *handle, int coherent_flag)
+				  dma_addr_t *handle, int coherent_flag,
+				  unsigned long attrs)
 {
 	struct page *page;
 	void *addr;
@@ -1488,7 +1509,7 @@ static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,
 	if (!addr)
 		return NULL;
 
-	*handle = __iommu_create_mapping(dev, &page, size);
+	*handle = __iommu_create_mapping(dev, &page, size, attrs);
 	if (*handle == DMA_ERROR_CODE)
 		goto err_mapping;
 
@@ -1522,7 +1543,7 @@ static void *__arm_iommu_alloc_attrs(struct device *dev, size_t size,
 
 	if (coherent_flag  == COHERENT || !gfpflags_allow_blocking(gfp))
 		return __iommu_alloc_simple(dev, size, gfp, handle,
-					    coherent_flag);
+					    coherent_flag, attrs);
 
 	/*
 	 * Following is a work-around (a.k.a. hack) to prevent pages
@@ -1537,7 +1558,7 @@ static void *__arm_iommu_alloc_attrs(struct device *dev, size_t size,
 	if (!pages)
 		return NULL;
 
-	*handle = __iommu_create_mapping(dev, pages, size);
+	*handle = __iommu_create_mapping(dev, pages, size, attrs);
 	if (*handle == DMA_ERROR_CODE)
 		goto err_buffer;
 
@@ -1672,27 +1693,6 @@ static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
 					 GFP_KERNEL);
 }
 
-static int __dma_direction_to_prot(enum dma_data_direction dir)
-{
-	int prot;
-
-	switch (dir) {
-	case DMA_BIDIRECTIONAL:
-		prot = IOMMU_READ | IOMMU_WRITE;
-		break;
-	case DMA_TO_DEVICE:
-		prot = IOMMU_READ;
-		break;
-	case DMA_FROM_DEVICE:
-		prot = IOMMU_WRITE;
-		break;
-	default:
-		prot = 0;
-	}
-
-	return prot;
-}
-
 /*
  * Map a part of the scatter-gather list into contiguous io address space
  */
@@ -1722,7 +1722,7 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
 		if (!is_coherent && (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
 			__dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
 
-		prot = __dma_direction_to_prot(dir);
+		prot = __dma_info_to_prot(dir, attrs);
 
 		ret = iommu_map(mapping->domain, iova, phys, len, prot);
 		if (ret < 0)
@@ -1930,7 +1930,7 @@ static dma_addr_t arm_coherent_iommu_map_page(struct device *dev, struct page *p
 	if (dma_addr == DMA_ERROR_CODE)
 		return dma_addr;
 
-	prot = __dma_direction_to_prot(dir);
+	prot = __dma_info_to_prot(dir, attrs);
 
 	ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot);
 	if (ret < 0)
@@ -2036,7 +2036,7 @@ static dma_addr_t arm_iommu_map_resource(struct device *dev,
 	if (dma_addr == DMA_ERROR_CODE)
 		return dma_addr;
 
-	prot = __dma_direction_to_prot(dir) | IOMMU_MMIO;
+	prot = __dma_info_to_prot(dir, attrs) | IOMMU_MMIO;
 
 	ret = iommu_map(mapping->domain, dma_addr, addr, len, prot);
 	if (ret < 0)
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 6/9] arm/dma-mapping: Implement DMA_ATTR_PRIVILEGED
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse-sgV2jX0FEOL9JmXXK+q4OQ, pdaly-sgV2jX0FEOL9JmXXK+q4OQ,
	jgebben-sgV2jX0FEOL9JmXXK+q4OQ, joro-zLv9SwRftAIdnm+yROfE0A,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	pratikp-sgV2jX0FEOL9JmXXK+q4OQ,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	robin.murphy-5wv7dgnIgG8, tzeng-sgV2jX0FEOL9JmXXK+q4OQ,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	will.deacon-5wv7dgnIgG8, mitchelh-sgV2jX0FEOL9JmXXK+q4OQ,
	vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
	dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
	linux-I+IVW8TIWO2tmTQ+vhA3Yw

The newly added DMA_ATTR_PRIVILEGED is useful for creating mappings that
are only accessible to privileged DMA engines.  Adding it to the
arm dma-mapping.c so that the ARM32 DMA IOMMU mapper can make use of it.

Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
Reviewed-by: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
---
 arch/arm/mm/dma-mapping.c | 60 +++++++++++++++++++++++------------------------
 1 file changed, 30 insertions(+), 30 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index ab77100..82d3e79 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1171,6 +1171,25 @@ static int __init dma_debug_do_init(void)
 
 #ifdef CONFIG_ARM_DMA_USE_IOMMU
 
+static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs)
+{
+	int prot = 0;
+
+	if (attrs & DMA_ATTR_PRIVILEGED)
+		prot |= IOMMU_PRIV;
+
+	switch (dir) {
+	case DMA_BIDIRECTIONAL:
+		return prot | IOMMU_READ | IOMMU_WRITE;
+	case DMA_TO_DEVICE:
+		return prot | IOMMU_READ;
+	case DMA_FROM_DEVICE:
+		return prot | IOMMU_WRITE;
+	default:
+		return prot;
+	}
+}
+
 /* IOMMU */
 
 static int extend_iommu_mapping(struct dma_iommu_mapping *mapping);
@@ -1394,7 +1413,8 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages,
  * Create a mapping in device IO address space for specified pages
  */
 static dma_addr_t
-__iommu_create_mapping(struct device *dev, struct page **pages, size_t size)
+__iommu_create_mapping(struct device *dev, struct page **pages, size_t size,
+		       unsigned long attrs)
 {
 	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
 	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
@@ -1419,7 +1439,7 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages,
 
 		len = (j - i) << PAGE_SHIFT;
 		ret = iommu_map(mapping->domain, iova, phys, len,
-				IOMMU_READ|IOMMU_WRITE);
+				__dma_info_to_prot(DMA_BIDIRECTIONAL, attrs));
 		if (ret < 0)
 			goto fail;
 		iova += len;
@@ -1476,7 +1496,8 @@ static struct page **__iommu_get_pages(void *cpu_addr, unsigned long attrs)
 }
 
 static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,
-				  dma_addr_t *handle, int coherent_flag)
+				  dma_addr_t *handle, int coherent_flag,
+				  unsigned long attrs)
 {
 	struct page *page;
 	void *addr;
@@ -1488,7 +1509,7 @@ static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,
 	if (!addr)
 		return NULL;
 
-	*handle = __iommu_create_mapping(dev, &page, size);
+	*handle = __iommu_create_mapping(dev, &page, size, attrs);
 	if (*handle == DMA_ERROR_CODE)
 		goto err_mapping;
 
@@ -1522,7 +1543,7 @@ static void *__arm_iommu_alloc_attrs(struct device *dev, size_t size,
 
 	if (coherent_flag  == COHERENT || !gfpflags_allow_blocking(gfp))
 		return __iommu_alloc_simple(dev, size, gfp, handle,
-					    coherent_flag);
+					    coherent_flag, attrs);
 
 	/*
 	 * Following is a work-around (a.k.a. hack) to prevent pages
@@ -1537,7 +1558,7 @@ static void *__arm_iommu_alloc_attrs(struct device *dev, size_t size,
 	if (!pages)
 		return NULL;
 
-	*handle = __iommu_create_mapping(dev, pages, size);
+	*handle = __iommu_create_mapping(dev, pages, size, attrs);
 	if (*handle == DMA_ERROR_CODE)
 		goto err_buffer;
 
@@ -1672,27 +1693,6 @@ static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
 					 GFP_KERNEL);
 }
 
-static int __dma_direction_to_prot(enum dma_data_direction dir)
-{
-	int prot;
-
-	switch (dir) {
-	case DMA_BIDIRECTIONAL:
-		prot = IOMMU_READ | IOMMU_WRITE;
-		break;
-	case DMA_TO_DEVICE:
-		prot = IOMMU_READ;
-		break;
-	case DMA_FROM_DEVICE:
-		prot = IOMMU_WRITE;
-		break;
-	default:
-		prot = 0;
-	}
-
-	return prot;
-}
-
 /*
  * Map a part of the scatter-gather list into contiguous io address space
  */
@@ -1722,7 +1722,7 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
 		if (!is_coherent && (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
 			__dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
 
-		prot = __dma_direction_to_prot(dir);
+		prot = __dma_info_to_prot(dir, attrs);
 
 		ret = iommu_map(mapping->domain, iova, phys, len, prot);
 		if (ret < 0)
@@ -1930,7 +1930,7 @@ static dma_addr_t arm_coherent_iommu_map_page(struct device *dev, struct page *p
 	if (dma_addr == DMA_ERROR_CODE)
 		return dma_addr;
 
-	prot = __dma_direction_to_prot(dir);
+	prot = __dma_info_to_prot(dir, attrs);
 
 	ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot);
 	if (ret < 0)
@@ -2036,7 +2036,7 @@ static dma_addr_t arm_iommu_map_resource(struct device *dev,
 	if (dma_addr == DMA_ERROR_CODE)
 		return dma_addr;
 
-	prot = __dma_direction_to_prot(dir) | IOMMU_MMIO;
+	prot = __dma_info_to_prot(dir, attrs) | IOMMU_MMIO;
 
 	ret = iommu_map(mapping->domain, dma_addr, addr, len, prot);
 	if (ret < 0)
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 6/9] arm/dma-mapping: Implement DMA_ATTR_PRIVILEGED
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: linux-arm-kernel

The newly added DMA_ATTR_PRIVILEGED is useful for creating mappings that
are only accessible to privileged DMA engines.  Adding it to the
arm dma-mapping.c so that the ARM32 DMA IOMMU mapper can make use of it.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm/mm/dma-mapping.c | 60 +++++++++++++++++++++++------------------------
 1 file changed, 30 insertions(+), 30 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index ab77100..82d3e79 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1171,6 +1171,25 @@ static int __init dma_debug_do_init(void)
 
 #ifdef CONFIG_ARM_DMA_USE_IOMMU
 
+static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs)
+{
+	int prot = 0;
+
+	if (attrs & DMA_ATTR_PRIVILEGED)
+		prot |= IOMMU_PRIV;
+
+	switch (dir) {
+	case DMA_BIDIRECTIONAL:
+		return prot | IOMMU_READ | IOMMU_WRITE;
+	case DMA_TO_DEVICE:
+		return prot | IOMMU_READ;
+	case DMA_FROM_DEVICE:
+		return prot | IOMMU_WRITE;
+	default:
+		return prot;
+	}
+}
+
 /* IOMMU */
 
 static int extend_iommu_mapping(struct dma_iommu_mapping *mapping);
@@ -1394,7 +1413,8 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages,
  * Create a mapping in device IO address space for specified pages
  */
 static dma_addr_t
-__iommu_create_mapping(struct device *dev, struct page **pages, size_t size)
+__iommu_create_mapping(struct device *dev, struct page **pages, size_t size,
+		       unsigned long attrs)
 {
 	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
 	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
@@ -1419,7 +1439,7 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages,
 
 		len = (j - i) << PAGE_SHIFT;
 		ret = iommu_map(mapping->domain, iova, phys, len,
-				IOMMU_READ|IOMMU_WRITE);
+				__dma_info_to_prot(DMA_BIDIRECTIONAL, attrs));
 		if (ret < 0)
 			goto fail;
 		iova += len;
@@ -1476,7 +1496,8 @@ static struct page **__iommu_get_pages(void *cpu_addr, unsigned long attrs)
 }
 
 static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,
-				  dma_addr_t *handle, int coherent_flag)
+				  dma_addr_t *handle, int coherent_flag,
+				  unsigned long attrs)
 {
 	struct page *page;
 	void *addr;
@@ -1488,7 +1509,7 @@ static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,
 	if (!addr)
 		return NULL;
 
-	*handle = __iommu_create_mapping(dev, &page, size);
+	*handle = __iommu_create_mapping(dev, &page, size, attrs);
 	if (*handle == DMA_ERROR_CODE)
 		goto err_mapping;
 
@@ -1522,7 +1543,7 @@ static void *__arm_iommu_alloc_attrs(struct device *dev, size_t size,
 
 	if (coherent_flag  == COHERENT || !gfpflags_allow_blocking(gfp))
 		return __iommu_alloc_simple(dev, size, gfp, handle,
-					    coherent_flag);
+					    coherent_flag, attrs);
 
 	/*
 	 * Following is a work-around (a.k.a. hack) to prevent pages
@@ -1537,7 +1558,7 @@ static void *__arm_iommu_alloc_attrs(struct device *dev, size_t size,
 	if (!pages)
 		return NULL;
 
-	*handle = __iommu_create_mapping(dev, pages, size);
+	*handle = __iommu_create_mapping(dev, pages, size, attrs);
 	if (*handle == DMA_ERROR_CODE)
 		goto err_buffer;
 
@@ -1672,27 +1693,6 @@ static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
 					 GFP_KERNEL);
 }
 
-static int __dma_direction_to_prot(enum dma_data_direction dir)
-{
-	int prot;
-
-	switch (dir) {
-	case DMA_BIDIRECTIONAL:
-		prot = IOMMU_READ | IOMMU_WRITE;
-		break;
-	case DMA_TO_DEVICE:
-		prot = IOMMU_READ;
-		break;
-	case DMA_FROM_DEVICE:
-		prot = IOMMU_WRITE;
-		break;
-	default:
-		prot = 0;
-	}
-
-	return prot;
-}
-
 /*
  * Map a part of the scatter-gather list into contiguous io address space
  */
@@ -1722,7 +1722,7 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
 		if (!is_coherent && (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
 			__dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
 
-		prot = __dma_direction_to_prot(dir);
+		prot = __dma_info_to_prot(dir, attrs);
 
 		ret = iommu_map(mapping->domain, iova, phys, len, prot);
 		if (ret < 0)
@@ -1930,7 +1930,7 @@ static dma_addr_t arm_coherent_iommu_map_page(struct device *dev, struct page *p
 	if (dma_addr == DMA_ERROR_CODE)
 		return dma_addr;
 
-	prot = __dma_direction_to_prot(dir);
+	prot = __dma_info_to_prot(dir, attrs);
 
 	ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot);
 	if (ret < 0)
@@ -2036,7 +2036,7 @@ static dma_addr_t arm_iommu_map_resource(struct device *dev,
 	if (dma_addr == DMA_ERROR_CODE)
 		return dma_addr;
 
-	prot = __dma_direction_to_prot(dir) | IOMMU_MMIO;
+	prot = __dma_info_to_prot(dir, attrs) | IOMMU_MMIO;
 
 	ret = iommu_map(mapping->domain, dma_addr, addr, len, prot);
 	if (ret < 0)
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 7/9] dmaengine: pl330: Make sure microcode is privileged
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse, pdaly, jgebben, joro, linux-kernel, pratikp, iommu,
	robin.murphy, tzeng, linux-arm-kernel, will.deacon, mitchelh,
	vinod.koul, dan.j.williams, linux
  Cc: sricharan

From: Mitchel Humpherys <mitchelh@codeaurora.org>

The PL330 is hard-wired such that instruction fetches on both the
manager and channel threads go out onto the bus with the "privileged"
bit set. This can become troublesome once there is an IOMMU or other
form of memory protection downstream, since those will typically be
programmed by the DMA mapping subsystem in the expectation of normal
unprivileged transactions (such as the PL330 channel threads' own data
accesses as currently configured by this driver).

To avoid the case of, say, an IOMMU blocking an unexpected privileged
transaction with a permission fault, use the newly-introduced
DMA_ATTR_PRIVILEGED attribute for the mapping of our microcode buffer.
That way the DMA layer can do whatever it needs to do to make things
continue to work as expected on more complex systems.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
[rm: remove now-redundant local variable, clarify commit message]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/dma/pl330.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 87fd015..5a90d0c 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -1864,9 +1864,10 @@ static int dmac_alloc_resources(struct pl330_dmac *pl330)
 	 * Alloc MicroCode buffer for 'chans' Channel threads.
 	 * A channel's buffer offset is (Channel_Id * MCODE_BUFF_PERCHAN)
 	 */
-	pl330->mcode_cpu = dma_alloc_coherent(pl330->ddma.dev,
+	pl330->mcode_cpu = dma_alloc_attrs(pl330->ddma.dev,
 				chans * pl330->mcbufsz,
-				&pl330->mcode_bus, GFP_KERNEL);
+				&pl330->mcode_bus, GFP_KERNEL,
+				DMA_ATTR_PRIVILEGED);
 	if (!pl330->mcode_cpu) {
 		dev_err(pl330->ddma.dev, "%s:%d Can't allocate memory!\n",
 			__func__, __LINE__);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 7/9] dmaengine: pl330: Make sure microcode is privileged
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse-sgV2jX0FEOL9JmXXK+q4OQ, pdaly-sgV2jX0FEOL9JmXXK+q4OQ,
	jgebben-sgV2jX0FEOL9JmXXK+q4OQ, joro-zLv9SwRftAIdnm+yROfE0A,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	pratikp-sgV2jX0FEOL9JmXXK+q4OQ,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	robin.murphy-5wv7dgnIgG8, tzeng-sgV2jX0FEOL9JmXXK+q4OQ,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	will.deacon-5wv7dgnIgG8, mitchelh-sgV2jX0FEOL9JmXXK+q4OQ,
	vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
	dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
	linux-I+IVW8TIWO2tmTQ+vhA3Yw

From: Mitchel Humpherys <mitchelh-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

The PL330 is hard-wired such that instruction fetches on both the
manager and channel threads go out onto the bus with the "privileged"
bit set. This can become troublesome once there is an IOMMU or other
form of memory protection downstream, since those will typically be
programmed by the DMA mapping subsystem in the expectation of normal
unprivileged transactions (such as the PL330 channel threads' own data
accesses as currently configured by this driver).

To avoid the case of, say, an IOMMU blocking an unexpected privileged
transaction with a permission fault, use the newly-introduced
DMA_ATTR_PRIVILEGED attribute for the mapping of our microcode buffer.
That way the DMA layer can do whatever it needs to do to make things
continue to work as expected on more complex systems.

Cc: Dan Williams <dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Vinod Koul <vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Reviewed-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Tested-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Acked-by: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
Acked-by: Vinod Koul <vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Mitchel Humpherys <mitchelh-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
[rm: remove now-redundant local variable, clarify commit message]
Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
---
 drivers/dma/pl330.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 87fd015..5a90d0c 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -1864,9 +1864,10 @@ static int dmac_alloc_resources(struct pl330_dmac *pl330)
 	 * Alloc MicroCode buffer for 'chans' Channel threads.
 	 * A channel's buffer offset is (Channel_Id * MCODE_BUFF_PERCHAN)
 	 */
-	pl330->mcode_cpu = dma_alloc_coherent(pl330->ddma.dev,
+	pl330->mcode_cpu = dma_alloc_attrs(pl330->ddma.dev,
 				chans * pl330->mcbufsz,
-				&pl330->mcode_bus, GFP_KERNEL);
+				&pl330->mcode_bus, GFP_KERNEL,
+				DMA_ATTR_PRIVILEGED);
 	if (!pl330->mcode_cpu) {
 		dev_err(pl330->ddma.dev, "%s:%d Can't allocate memory!\n",
 			__func__, __LINE__);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 7/9] dmaengine: pl330: Make sure microcode is privileged
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: linux-arm-kernel

From: Mitchel Humpherys <mitchelh@codeaurora.org>

The PL330 is hard-wired such that instruction fetches on both the
manager and channel threads go out onto the bus with the "privileged"
bit set. This can become troublesome once there is an IOMMU or other
form of memory protection downstream, since those will typically be
programmed by the DMA mapping subsystem in the expectation of normal
unprivileged transactions (such as the PL330 channel threads' own data
accesses as currently configured by this driver).

To avoid the case of, say, an IOMMU blocking an unexpected privileged
transaction with a permission fault, use the newly-introduced
DMA_ATTR_PRIVILEGED attribute for the mapping of our microcode buffer.
That way the DMA layer can do whatever it needs to do to make things
continue to work as expected on more complex systems.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
[rm: remove now-redundant local variable, clarify commit message]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/dma/pl330.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 87fd015..5a90d0c 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -1864,9 +1864,10 @@ static int dmac_alloc_resources(struct pl330_dmac *pl330)
 	 * Alloc MicroCode buffer for 'chans' Channel threads.
 	 * A channel's buffer offset is (Channel_Id * MCODE_BUFF_PERCHAN)
 	 */
-	pl330->mcode_cpu = dma_alloc_coherent(pl330->ddma.dev,
+	pl330->mcode_cpu = dma_alloc_attrs(pl330->ddma.dev,
 				chans * pl330->mcbufsz,
-				&pl330->mcode_bus, GFP_KERNEL);
+				&pl330->mcode_bus, GFP_KERNEL,
+				DMA_ATTR_PRIVILEGED);
 	if (!pl330->mcode_cpu) {
 		dev_err(pl330->ddma.dev, "%s:%d Can't allocate memory!\n",
 			__func__, __LINE__);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 8/9] iommu/arm-smmu: Set privileged attribute to 'default' instead of 'unprivileged'
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse, pdaly, jgebben, joro, linux-kernel, pratikp, iommu,
	robin.murphy, tzeng, linux-arm-kernel, will.deacon, mitchelh,
	vinod.koul, dan.j.williams, linux
  Cc: sricharan

Currently the driver sets all the device transactions privileges
to UNPRIVILEGED, but there are cases where the iommu masters wants
to isolate privileged supervisor and unprivileged user.
So don't override the privileged setting to unprivileged, instead
set it to default as incoming and let it be controlled by the pagetable
settings.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
---
 drivers/iommu/arm-smmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index a60cded..73a0a25 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1214,7 +1214,7 @@ static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
 			continue;
 
 		s2cr[idx].type = type;
-		s2cr[idx].privcfg = S2CR_PRIVCFG_UNPRIV;
+		s2cr[idx].privcfg = S2CR_PRIVCFG_DEFAULT;
 		s2cr[idx].cbndx = cbndx;
 		arm_smmu_write_s2cr(smmu, idx);
 	}
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 8/9] iommu/arm-smmu: Set privileged attribute to 'default' instead of 'unprivileged'
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse-sgV2jX0FEOL9JmXXK+q4OQ, pdaly-sgV2jX0FEOL9JmXXK+q4OQ,
	jgebben-sgV2jX0FEOL9JmXXK+q4OQ, joro-zLv9SwRftAIdnm+yROfE0A,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	pratikp-sgV2jX0FEOL9JmXXK+q4OQ,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	robin.murphy-5wv7dgnIgG8, tzeng-sgV2jX0FEOL9JmXXK+q4OQ,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	will.deacon-5wv7dgnIgG8, mitchelh-sgV2jX0FEOL9JmXXK+q4OQ,
	vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
	dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
	linux-I+IVW8TIWO2tmTQ+vhA3Yw

Currently the driver sets all the device transactions privileges
to UNPRIVILEGED, but there are cases where the iommu masters wants
to isolate privileged supervisor and unprivileged user.
So don't override the privileged setting to unprivileged, instead
set it to default as incoming and let it be controlled by the pagetable
settings.

Acked-by: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 drivers/iommu/arm-smmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index a60cded..73a0a25 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1214,7 +1214,7 @@ static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
 			continue;
 
 		s2cr[idx].type = type;
-		s2cr[idx].privcfg = S2CR_PRIVCFG_UNPRIV;
+		s2cr[idx].privcfg = S2CR_PRIVCFG_DEFAULT;
 		s2cr[idx].cbndx = cbndx;
 		arm_smmu_write_s2cr(smmu, idx);
 	}
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 8/9] iommu/arm-smmu: Set privileged attribute to 'default' instead of 'unprivileged'
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: linux-arm-kernel

Currently the driver sets all the device transactions privileges
to UNPRIVILEGED, but there are cases where the iommu masters wants
to isolate privileged supervisor and unprivileged user.
So don't override the privileged setting to unprivileged, instead
set it to default as incoming and let it be controlled by the pagetable
settings.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
---
 drivers/iommu/arm-smmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index a60cded..73a0a25 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1214,7 +1214,7 @@ static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
 			continue;
 
 		s2cr[idx].type = type;
-		s2cr[idx].privcfg = S2CR_PRIVCFG_UNPRIV;
+		s2cr[idx].privcfg = S2CR_PRIVCFG_DEFAULT;
 		s2cr[idx].cbndx = cbndx;
 		arm_smmu_write_s2cr(smmu, idx);
 	}
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 9/9] Revert "iommu/arm-smmu: Set PRIVCFG in stage 1 STEs"
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse, pdaly, jgebben, joro, linux-kernel, pratikp, iommu,
	robin.murphy, tzeng, linux-arm-kernel, will.deacon, mitchelh,
	vinod.koul, dan.j.williams, linux
  Cc: sricharan

From: Robin Murphy <robin.murphy@arm.com>

This reverts commit df5e1a0f2a2d779ad467a691203bcbc74d75690e.

Now that proper privileged mappings can be requested via IOMMU_PRIV,
unconditionally overriding the incoming PRIVCFG becomes the wrong thing
to do, so stop it.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/arm-smmu-v3.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 4d6ec44..7d45d8b 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -269,9 +269,6 @@
 #define STRTAB_STE_1_SHCFG_INCOMING	1UL
 #define STRTAB_STE_1_SHCFG_SHIFT	44
 
-#define STRTAB_STE_1_PRIVCFG_UNPRIV	2UL
-#define STRTAB_STE_1_PRIVCFG_SHIFT	48
-
 #define STRTAB_STE_2_S2VMID_SHIFT	0
 #define STRTAB_STE_2_S2VMID_MASK	0xffffUL
 #define STRTAB_STE_2_VTCR_SHIFT		32
@@ -1073,9 +1070,7 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid,
 #ifdef CONFIG_PCI_ATS
 			 STRTAB_STE_1_EATS_TRANS << STRTAB_STE_1_EATS_SHIFT |
 #endif
-			 STRTAB_STE_1_STRW_NSEL1 << STRTAB_STE_1_STRW_SHIFT |
-			 STRTAB_STE_1_PRIVCFG_UNPRIV <<
-			 STRTAB_STE_1_PRIVCFG_SHIFT);
+			 STRTAB_STE_1_STRW_NSEL1 << STRTAB_STE_1_STRW_SHIFT);
 
 		if (smmu->features & ARM_SMMU_FEAT_STALLS)
 			dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 9/9] Revert "iommu/arm-smmu: Set PRIVCFG in stage 1 STEs"
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: jcrouse-sgV2jX0FEOL9JmXXK+q4OQ, pdaly-sgV2jX0FEOL9JmXXK+q4OQ,
	jgebben-sgV2jX0FEOL9JmXXK+q4OQ, joro-zLv9SwRftAIdnm+yROfE0A,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	pratikp-sgV2jX0FEOL9JmXXK+q4OQ,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	robin.murphy-5wv7dgnIgG8, tzeng-sgV2jX0FEOL9JmXXK+q4OQ,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	will.deacon-5wv7dgnIgG8, mitchelh-sgV2jX0FEOL9JmXXK+q4OQ,
	vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
	dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
	linux-I+IVW8TIWO2tmTQ+vhA3Yw

From: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>

This reverts commit df5e1a0f2a2d779ad467a691203bcbc74d75690e.

Now that proper privileged mappings can be requested via IOMMU_PRIV,
unconditionally overriding the incoming PRIVCFG becomes the wrong thing
to do, so stop it.

Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
---
 drivers/iommu/arm-smmu-v3.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 4d6ec44..7d45d8b 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -269,9 +269,6 @@
 #define STRTAB_STE_1_SHCFG_INCOMING	1UL
 #define STRTAB_STE_1_SHCFG_SHIFT	44
 
-#define STRTAB_STE_1_PRIVCFG_UNPRIV	2UL
-#define STRTAB_STE_1_PRIVCFG_SHIFT	48
-
 #define STRTAB_STE_2_S2VMID_SHIFT	0
 #define STRTAB_STE_2_S2VMID_MASK	0xffffUL
 #define STRTAB_STE_2_VTCR_SHIFT		32
@@ -1073,9 +1070,7 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid,
 #ifdef CONFIG_PCI_ATS
 			 STRTAB_STE_1_EATS_TRANS << STRTAB_STE_1_EATS_SHIFT |
 #endif
-			 STRTAB_STE_1_STRW_NSEL1 << STRTAB_STE_1_STRW_SHIFT |
-			 STRTAB_STE_1_PRIVCFG_UNPRIV <<
-			 STRTAB_STE_1_PRIVCFG_SHIFT);
+			 STRTAB_STE_1_STRW_NSEL1 << STRTAB_STE_1_STRW_SHIFT);
 
 		if (smmu->features & ARM_SMMU_FEAT_STALLS)
 			dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH V9 9/9] Revert "iommu/arm-smmu: Set PRIVCFG in stage 1 STEs"
@ 2017-01-06 13:28   ` Sricharan R
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan R @ 2017-01-06 13:28 UTC (permalink / raw)
  To: linux-arm-kernel

From: Robin Murphy <robin.murphy@arm.com>

This reverts commit df5e1a0f2a2d779ad467a691203bcbc74d75690e.

Now that proper privileged mappings can be requested via IOMMU_PRIV,
unconditionally overriding the incoming PRIVCFG becomes the wrong thing
to do, so stop it.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/arm-smmu-v3.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 4d6ec44..7d45d8b 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -269,9 +269,6 @@
 #define STRTAB_STE_1_SHCFG_INCOMING	1UL
 #define STRTAB_STE_1_SHCFG_SHIFT	44
 
-#define STRTAB_STE_1_PRIVCFG_UNPRIV	2UL
-#define STRTAB_STE_1_PRIVCFG_SHIFT	48
-
 #define STRTAB_STE_2_S2VMID_SHIFT	0
 #define STRTAB_STE_2_S2VMID_MASK	0xffffUL
 #define STRTAB_STE_2_VTCR_SHIFT		32
@@ -1073,9 +1070,7 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid,
 #ifdef CONFIG_PCI_ATS
 			 STRTAB_STE_1_EATS_TRANS << STRTAB_STE_1_EATS_SHIFT |
 #endif
-			 STRTAB_STE_1_STRW_NSEL1 << STRTAB_STE_1_STRW_SHIFT |
-			 STRTAB_STE_1_PRIVCFG_UNPRIV <<
-			 STRTAB_STE_1_PRIVCFG_SHIFT);
+			 STRTAB_STE_1_STRW_NSEL1 << STRTAB_STE_1_STRW_SHIFT);
 
 		if (smmu->features & ARM_SMMU_FEAT_STALLS)
 			dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH] iommu: Better document the IOMMU_PRIV flag
  2017-01-06 13:28   ` Sricharan R
@ 2017-01-27 12:22       ` Robin Murphy
  -1 siblings, 0 replies; 34+ messages in thread
From: Robin Murphy @ 2017-01-27 12:22 UTC (permalink / raw)
  To: will.deacon-5wv7dgnIgG8
  Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r

This is a fairly subtle thing - let's make sure it's described as
clearly as possible to avoid potential misunderstandings.

Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
---

Having another look through the IOMMU_PRIV series, I wasn't convinced
that the original comment was really all that helpful - I'm happy for
this to be squashed in if you like.

Robin.

 include/linux/iommu.h | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 69e2417a2965..3c830e153069 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -32,10 +32,13 @@
 #define IOMMU_NOEXEC	(1 << 3)
 #define IOMMU_MMIO	(1 << 4) /* e.g. things like MSI doorbells */
 /*
- * This is to make the IOMMU API setup privileged
- * mapppings accessible by the master only at higher
- * privileged execution level and inaccessible at
- * less privileged levels.
+ * Where the bus hardware includes a privilege level as part of its access type
+ * markings, and certain devices are capable of issuing transactions marked as
+ * either 'supervisor' or 'user', the IOMMU_PRIV flag requests that the other
+ * given permission flags only apply to accesses at the higher privilege level,
+ * and that unprivileged transactions should have as little access as possible.
+ * This would usually imply the same permissions as kernel mappings on the CPU,
+ * if the IOMMU page table format is equivalent.
  */
 #define IOMMU_PRIV	(1 << 5)
 
-- 
2.11.0.dirty

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* [PATCH] iommu: Better document the IOMMU_PRIV flag
@ 2017-01-27 12:22       ` Robin Murphy
  0 siblings, 0 replies; 34+ messages in thread
From: Robin Murphy @ 2017-01-27 12:22 UTC (permalink / raw)
  To: linux-arm-kernel

This is a fairly subtle thing - let's make sure it's described as
clearly as possible to avoid potential misunderstandings.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---

Having another look through the IOMMU_PRIV series, I wasn't convinced
that the original comment was really all that helpful - I'm happy for
this to be squashed in if you like.

Robin.

 include/linux/iommu.h | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 69e2417a2965..3c830e153069 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -32,10 +32,13 @@
 #define IOMMU_NOEXEC	(1 << 3)
 #define IOMMU_MMIO	(1 << 4) /* e.g. things like MSI doorbells */
 /*
- * This is to make the IOMMU API setup privileged
- * mapppings accessible by the master only at higher
- * privileged execution level and inaccessible at
- * less privileged levels.
+ * Where the bus hardware includes a privilege level as part of its access type
+ * markings, and certain devices are capable of issuing transactions marked as
+ * either 'supervisor' or 'user', the IOMMU_PRIV flag requests that the other
+ * given permission flags only apply to accesses@the higher privilege level,
+ * and that unprivileged transactions should have as little access as possible.
+ * This would usually imply the same permissions as kernel mappings on the CPU,
+ * if the IOMMU page table format is equivalent.
  */
 #define IOMMU_PRIV	(1 << 5)
 
-- 
2.11.0.dirty

^ permalink raw reply related	[flat|nested] 34+ messages in thread

* RE: [PATCH] iommu: Better document the IOMMU_PRIV flag
  2017-01-27 12:22       ` Robin Murphy
@ 2017-01-27 16:58           ` Sricharan
  -1 siblings, 0 replies; 34+ messages in thread
From: Sricharan @ 2017-01-27 16:58 UTC (permalink / raw)
  To: 'Robin Murphy', will.deacon-5wv7dgnIgG8
  Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r

Hi Robin,

>-----Original Message-----
>From: linux-arm-kernel [mailto:linux-arm-kernel-bounces-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org] On Behalf Of Robin Murphy
>Sent: Friday, January 27, 2017 5:53 PM
>To: will.deacon-5wv7dgnIgG8@public.gmane.org
>Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org; sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org; linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
>Subject: [PATCH] iommu: Better document the IOMMU_PRIV flag
>
>This is a fairly subtle thing - let's make sure it's described as
>clearly as possible to avoid potential misunderstandings.
>
>Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
>---
>
>Having another look through the IOMMU_PRIV series, I wasn't convinced
>that the original comment was really all that helpful - I'm happy for
>this to be squashed in if you like.
>
>Robin.
>
> include/linux/iommu.h | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
>diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>index 69e2417a2965..3c830e153069 100644
>--- a/include/linux/iommu.h
>+++ b/include/linux/iommu.h
>@@ -32,10 +32,13 @@
> #define IOMMU_NOEXEC	(1 << 3)
> #define IOMMU_MMIO	(1 << 4) /* e.g. things like MSI doorbells */
> /*
>- * This is to make the IOMMU API setup privileged
>- * mapppings accessible by the master only at higher
>- * privileged execution level and inaccessible at
>- * less privileged levels.
>+ * Where the bus hardware includes a privilege level as part of its access type
>+ * markings, and certain devices are capable of issuing transactions marked as
>+ * either 'supervisor' or 'user', the IOMMU_PRIV flag requests that the other
>+ * given permission flags only apply to accesses at the higher privilege level,
>+ * and that unprivileged transactions should have as little access as possible.
>+ * This would usually imply the same permissions as kernel mappings on the CPU,
>+ * if the IOMMU page table format is equivalent.
>  */

Agree, gives much more insight.

Regards,
  Sricharan

^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH] iommu: Better document the IOMMU_PRIV flag
@ 2017-01-27 16:58           ` Sricharan
  0 siblings, 0 replies; 34+ messages in thread
From: Sricharan @ 2017-01-27 16:58 UTC (permalink / raw)
  To: linux-arm-kernel

Hi Robin,

>-----Original Message-----
>From: linux-arm-kernel [mailto:linux-arm-kernel-bounces at lists.infradead.org] On Behalf Of Robin Murphy
>Sent: Friday, January 27, 2017 5:53 PM
>To: will.deacon at arm.com
>Cc: iommu at lists.linux-foundation.org; sricharan at codeaurora.org; linux-arm-kernel at lists.infradead.org
>Subject: [PATCH] iommu: Better document the IOMMU_PRIV flag
>
>This is a fairly subtle thing - let's make sure it's described as
>clearly as possible to avoid potential misunderstandings.
>
>Signed-off-by: Robin Murphy <robin.murphy@arm.com>
>---
>
>Having another look through the IOMMU_PRIV series, I wasn't convinced
>that the original comment was really all that helpful - I'm happy for
>this to be squashed in if you like.
>
>Robin.
>
> include/linux/iommu.h | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
>diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>index 69e2417a2965..3c830e153069 100644
>--- a/include/linux/iommu.h
>+++ b/include/linux/iommu.h
>@@ -32,10 +32,13 @@
> #define IOMMU_NOEXEC	(1 << 3)
> #define IOMMU_MMIO	(1 << 4) /* e.g. things like MSI doorbells */
> /*
>- * This is to make the IOMMU API setup privileged
>- * mapppings accessible by the master only at higher
>- * privileged execution level and inaccessible at
>- * less privileged levels.
>+ * Where the bus hardware includes a privilege level as part of its access type
>+ * markings, and certain devices are capable of issuing transactions marked as
>+ * either 'supervisor' or 'user', the IOMMU_PRIV flag requests that the other
>+ * given permission flags only apply to accesses at the higher privilege level,
>+ * and that unprivileged transactions should have as little access as possible.
>+ * This would usually imply the same permissions as kernel mappings on the CPU,
>+ * if the IOMMU page table format is equivalent.
>  */

Agree, gives much more insight.

Regards,
  Sricharan

^ permalink raw reply	[flat|nested] 34+ messages in thread

end of thread, other threads:[~2017-01-27 16:58 UTC | newest]

Thread overview: 34+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-01-06 13:28 [PATCH V9 0/9] Add support for privileged mappings Sricharan R
2017-01-06 13:28 ` Sricharan R
2017-01-06 13:28 ` Sricharan R
2017-01-06 13:28 ` [PATCH V9 1/9] iommu: add IOMMU_PRIV attribute Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28   ` Sricharan R
     [not found]   ` <1483709296-32761-2-git-send-email-sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2017-01-27 12:22     ` [PATCH] iommu: Better document the IOMMU_PRIV flag Robin Murphy
2017-01-27 12:22       ` Robin Murphy
     [not found]       ` <edc67cc1775f3bafb6895346184e8042fd881ba4.1485519627.git.robin.murphy-5wv7dgnIgG8@public.gmane.org>
2017-01-27 16:58         ` Sricharan
2017-01-27 16:58           ` Sricharan
2017-01-06 13:28 ` [PATCH V9 2/9] iommu/io-pgtable-arm: add support for " Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28 ` [PATCH V9 3/9] iommu/io-pgtable-arm-v7s: Add " Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28 ` [PATCH V9 4/9] common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28 ` [PATCH V9 5/9] arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28 ` [PATCH V9 6/9] arm/dma-mapping: " Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28 ` [PATCH V9 7/9] dmaengine: pl330: Make sure microcode is privileged Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28 ` [PATCH V9 8/9] iommu/arm-smmu: Set privileged attribute to 'default' instead of 'unprivileged' Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28 ` [PATCH V9 9/9] Revert "iommu/arm-smmu: Set PRIVCFG in stage 1 STEs" Sricharan R
2017-01-06 13:28   ` Sricharan R
2017-01-06 13:28   ` Sricharan R

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.