Hi Linus,
Very small pull request on dma-buf for 4.2 merge window. May I request
you to please pull?
The following changes since commit 5ebe6afaf0057ac3eaeb98defd5456894b446d22:
Linux 4.1-rc2 (2015-05-03 19:22:23 -0700)
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/sumits/dma-buf.git
tags/dma-buf-for-4.2
for you to fetch changes up to 5136629dc5a19701746abd7c8ad98ce0b84dda1d:
dma-buf: Minor coding style fixes (2015-05-21 11:29:59 +0530)
----------------------------------------------------------------
Minor changes for 4.2
- add ref-counting for kernel modules as exporters
- minor code style fixes
----------------------------------------------------------------
Jagan Teki (1):
dma-buf: Minor coding style fixes
Sumit Semwal (1):
dma-buf: add ref counting for module as exporter
drivers/dma-buf/dma-buf.c | 19 ++++++++++++++++---
drivers/dma-buf/reservation.c | 9 ++++++---
drivers/dma-buf/seqno-fence.c | 8 +++++++-
include/linux/dma-buf.h | 10 ++++++++--
4 files changed, 37 insertions(+), 9 deletions(-)
Thanks and best regards,
Sumit.
The outcome of the previous RFC about how do secure data path was the need
of a secure memory allocator (https://lkml.org/lkml/2015/5/5/551)
SMAF goal is to provide a framework that allow allocating and securing
memory by using dma_buf. Each platform have it own way to perform those two
features so SMAF design allow to register helper modules to perform them.
To be sure to select the best allocation method for devices SMAF implement
deferred allocation mechanism: memory allocation is only done when the first
device effectively required it.
Allocator modules have to implement a match() to let SMAF know if they are
compatibles with devices needs.
This patch set provide an example of allocator module which use
dma_{alloc/free/mmap}_attrs() and check if at least one device have
coherent_dma_mask set to DMA_BIT_MASK(32) in match function.
I have named smaf-cma.c like it is done for drm_gem_cma_helper.c even if
a better name could be found for this file.
Secure modules are responsibles of granting and revoking devices access rights
on the memory. Secure module is also called to check if CPU map memory into
kernel and user address spaces.
An example of secure module implementation can be found here:
http://git.linaro.org/people/benjamin.gaignard/optee-sdp.git
This code isn't yet part of the patch set because it depends on generic TEE
which is still under discussion (https://lwn.net/Articles/644646/)
For allocation part of SMAF code I get inspirated by Sumit Semwal work about
constraint aware allocator.
Benjamin Gaignard (2):
create SMAF module
SMAF: add CMA allocator
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/smaf/Kconfig | 11 +
drivers/smaf/Makefile | 2 +
drivers/smaf/smaf-cma.c | 198 ++++++++++++
drivers/smaf/smaf-core.c | 674 +++++++++++++++++++++++++++++++++++++++++
include/linux/smaf-allocator.h | 43 +++
include/linux/smaf-secure.h | 62 ++++
include/uapi/linux/smaf.h | 48 +++
9 files changed, 1041 insertions(+)
create mode 100644 drivers/smaf/Kconfig
create mode 100644 drivers/smaf/Makefile
create mode 100644 drivers/smaf/smaf-cma.c
create mode 100644 drivers/smaf/smaf-core.c
create mode 100644 include/linux/smaf-allocator.h
create mode 100644 include/linux/smaf-secure.h
create mode 100644 include/uapi/linux/smaf.h
--
1.9.1
From: Rob Clark <robdclark(a)gmail.com>
For devices which have constraints about maximum number of segments in
an sglist. For example, a device which could only deal with contiguous
buffers would set max_segment_count to 1.
The initial motivation is for devices sharing buffers via dma-buf,
to allow the buffer exporter to know the constraints of other
devices which have attached to the buffer. The dma_mask and fields
in 'struct device_dma_parameters' tell the exporter everything else
that is needed, except whether the importer has constraints about
maximum number of segments.
Signed-off-by: Rob Clark <robdclark(a)gmail.com>
[sumits: Minor updates wrt comments]
Signed-off-by: Sumit Semwal <sumit.semwal(a)linaro.org>
---
v3: include Robin Murphy's fix[1] for handling '0' as a value for
max_segment_count
v2: minor updates wrt comments on the first version
[1]: http://article.gmane.org/gmane.linux.kernel.iommu/8175/
include/linux/device.h | 1 +
include/linux/dma-mapping.h | 19 +++++++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/include/linux/device.h b/include/linux/device.h
index fb506738f7b7..a32f9b67315c 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -647,6 +647,7 @@ struct device_dma_parameters {
* sg limitations.
*/
unsigned int max_segment_size;
+ unsigned int max_segment_count; /* INT_MAX for unlimited */
unsigned long segment_boundary_mask;
};
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index c3007cb4bfa6..d3351a36d5ec 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -154,6 +154,25 @@ static inline unsigned int dma_set_max_seg_size(struct device *dev,
return -EIO;
}
+#define DMA_SEGMENTS_MAX_SEG_COUNT ((unsigned int) INT_MAX)
+
+static inline unsigned int dma_get_max_seg_count(struct device *dev)
+{
+ if (dev->dma_parms && dev->dma_parms->max_segment_count)
+ return dev->dma_parms->max_segment_count;
+ return DMA_SEGMENTS_MAX_SEG_COUNT;
+}
+
+static inline int dma_set_max_seg_count(struct device *dev,
+ unsigned int count)
+{
+ if (dev->dma_parms) {
+ dev->dma_parms->max_segment_count = count;
+ return 0;
+ }
+ return -EIO;
+}
+
static inline unsigned long dma_get_seg_boundary(struct device *dev)
{
return dev->dma_parms ?
--
1.9.1
