Re: [PATCH 2/2] dma-buf: add helpers for attacher dma-parms
On Fri, Jul 20, 2012 at 10:09 PM, Rob Clark rob.cl...@linaro.org wrote:
Fyi, Daniel Vetter had suggested on IRC that it would be cleaner to
have a single helper fxn that most-restrictive union of all attached
device's dma_parms. Really this should include dma_mask and
coherent_dma_mask, I think. But that touches a lot of other places in
the code. If no one objects to the cleanup of moving
dma_mask/coherent_dma_mask into dma_parms, I'll do this first.
So anyways, don't consider this patch yet for inclusion, I'll make an
updated one based on dma_parms..
Hi Rob,
Any news on this patch-set?
BR,
-R
BR,
~Sumit.
On Thu, Jul 19, 2012 at 11:23 AM, Rob Clark rob.cl...@linaro.org wrote:
From: Rob Clark r...@ti.com
Add some helpers to iterate through all attachers and get the most
restrictive segment size/count/boundary.
Signed-off-by: Rob Clark r...@ti.com
---
drivers/base/dma-buf.c | 63
+++
include/linux/dma-buf.h | 19 ++
2 files changed, 82 insertions(+)
diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index 24e88fe..757ee20 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -192,6 +192,69 @@ void dma_buf_put(struct dma_buf *dmabuf)
EXPORT_SYMBOL_GPL(dma_buf_put);
/**
+ * dma_buf_max_seg_size - helper for exporters to get the minimum of
+ * all attached device's max segment size
+ */
+unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach;
+ unsigned int max = (unsigned int)-1;
+
+ if (WARN_ON(!dmabuf))
+ return 0;
+
+ mutex_lock(dmabuf-lock);
+ list_for_each_entry(attach, dmabuf-attachments, node)
+ max = min(max, dma_get_max_seg_size(attach-dev));
+ mutex_unlock(dmabuf-lock);
+
+ return max;
+}
+EXPORT_SYMBOL_GPL(dma_buf_max_seg_size);
+
+/**
+ * dma_buf_max_seg_count - helper for exporters to get the minimum of
+ * all attached device's max segment count
+ */
+unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach;
+ unsigned int max = (unsigned int)-1;
+
+ if (WARN_ON(!dmabuf))
+ return 0;
+
+ mutex_lock(dmabuf-lock);
+ list_for_each_entry(attach, dmabuf-attachments, node)
+ max = min(max, dma_get_max_seg_count(attach-dev));
+ mutex_unlock(dmabuf-lock);
+
+ return max;
+}
+EXPORT_SYMBOL_GPL(dma_buf_max_seg_count);
+
+/**
+ * dma_buf_get_seg_boundary - helper for exporters to get the most
+ * restrictive segment alignment of all the attached devices
+ */
+unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach;
+ unsigned int mask = (unsigned int)-1;
+
+ if (WARN_ON(!dmabuf))
+ return 0;
+
+ mutex_lock(dmabuf-lock);
+ list_for_each_entry(attach, dmabuf-attachments, node)
+ mask = dma_get_seg_boundary(attach-dev);
+ mutex_unlock(dmabuf-lock);
+
+ return mask;
+}
+EXPORT_SYMBOL_GPL(dma_buf_get_seg_boundary);
+
+/**
* dma_buf_attach - Add the device to dma_buf's attachments list;
optionally,
* calls attach() of dma_buf_ops to allow device-specific attach
functionality
* @dmabuf:[in]buffer to attach device to.
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index eb48f38..9533b9b 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -167,6 +167,10 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags);
struct dma_buf *dma_buf_get(int fd);
void dma_buf_put(struct dma_buf *dmabuf);
+unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf);
+unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf);
+unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf);
+
struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *,
enum dma_data_direction);
void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table
*,
@@ -220,6 +224,21 @@ static inline void dma_buf_put(struct dma_buf *dmabuf)
return;
}
+static inline unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf)
+{
+ return 0;
+}
+
+static inline unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf)
+{
+ return 0;
+}
+
+static inline unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf)
+{
+ return 0;
+}
+
static inline struct sg_table *dma_buf_map_attachment(
struct dma_buf_attachment *attach, enum dma_data_direction write)
{
--
1.7.9.5
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Re: [PATCH 2/2] dma-buf: add helpers for attacher dma-parms
Hi Rob,
On 07/19/2012 06:23 PM, Rob Clark wrote:
From: Rob Clark r...@ti.com
Add some helpers to iterate through all attachers and get the most
restrictive segment size/count/boundary.
Signed-off-by: Rob Clark r...@ti.com
---
drivers/base/dma-buf.c | 63
+++
include/linux/dma-buf.h | 19 ++
2 files changed, 82 insertions(+)
diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index 24e88fe..757ee20 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -192,6 +192,69 @@ void dma_buf_put(struct dma_buf *dmabuf)
EXPORT_SYMBOL_GPL(dma_buf_put);
/**
+ * dma_buf_max_seg_size - helper for exporters to get the minimum of
+ * all attached device's max segment size
+ */
+unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach;
+ unsigned int max = (unsigned int)-1;
+
+ if (WARN_ON(!dmabuf))
+ return 0;
Maybe you should change return type to 'int' and return -EINVAL here?
+
+ mutex_lock(dmabuf-lock);
+ list_for_each_entry(attach, dmabuf-attachments, node)
+ max = min(max, dma_get_max_seg_size(attach-dev));
+ mutex_unlock(dmabuf-lock);
+
+ return max;
+}
+EXPORT_SYMBOL_GPL(dma_buf_max_seg_size);
+
+/**
+ * dma_buf_max_seg_count - helper for exporters to get the minimum of
+ * all attached device's max segment count
+ */
+unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach;
+ unsigned int max = (unsigned int)-1;
+
+ if (WARN_ON(!dmabuf))
+ return 0;
maybe return -EINVAL here?
+
+ mutex_lock(dmabuf-lock);
+ list_for_each_entry(attach, dmabuf-attachments, node)
+ max = min(max, dma_get_max_seg_count(attach-dev));
I think that there is a bug here.
Assume that there are two deices on the list, one using unlimited number of
segments (value 0), the second one needs a contiguous buffer (value 1).
The result of the function is 0 = min(0, 2).
The return value 0 indicates that the unlimited number of sg segments is
accepted what is *wrong* because the correct value should be 1.
I recommend to change the semantics for unlimited number of segments
from 'value 0' to:
#define DMA_SEGMENTS_COUNT_UNLIMITED ((unsigned long)INT_MAX)
Using INT_MAX will allow using safe conversions between signed and
unsigned integers.
+ mutex_unlock(dmabuf-lock);
+
+ return max;
+}
+EXPORT_SYMBOL_GPL(dma_buf_max_seg_count);
+
+/**
+ * dma_buf_get_seg_boundary - helper for exporters to get the most
+ * restrictive segment alignment of all the attached devices
+ */
+unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach;
+ unsigned int mask = (unsigned int)-1;
+
+ if (WARN_ON(!dmabuf))
+ return 0;
+
+ mutex_lock(dmabuf-lock);
+ list_for_each_entry(attach, dmabuf-attachments, node)
+ mask = dma_get_seg_boundary(attach-dev);
+ mutex_unlock(dmabuf-lock);
+
+ return mask;
+}
+EXPORT_SYMBOL_GPL(dma_buf_get_seg_boundary);
+
+/**
* dma_buf_attach - Add the device to dma_buf's attachments list; optionally,
* calls attach() of dma_buf_ops to allow device-specific attach
functionality
* @dmabuf: [in]buffer to attach device to.
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index eb48f38..9533b9b 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -167,6 +167,10 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags);
struct dma_buf *dma_buf_get(int fd);
void dma_buf_put(struct dma_buf *dmabuf);
+unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf);
+unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf);
+unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf);
Instead of adding an army of new handlers you could provide a single helper:
int dma_buf_get_parameters(struct dma_buf *dmabuf,
struct device_dma_parameters *params);
This function will fill *params with lowest common DMA requirements for
all devices on attachment list. Return value can be used to diagnose
errors like incorrectly initialized dma_buf pointer
(like no attachments on an attachment list).
Moreover, there will be no need to add a new handler every time
device_dma_parameters is extended.
Regards,
Tomasz Stanislawski
+
struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *,
enum dma_data_direction);
void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *,
@@ -220,6 +224,21 @@ static inline void dma_buf_put(struct dma_buf *dmabuf)
return;
}
+static inline unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf)
+{
+ return 0;
+}
+
+static inline unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf)
+{
+ return 0;
+}
+
+static
Re: [PATCH 2/2] dma-buf: add helpers for attacher dma-parms
Tomasz Stanislawski t.stanisl...@samsung.com writes: I recommend to change the semantics for unlimited number of segments from 'value 0' to: #define DMA_SEGMENTS_COUNT_UNLIMITED ((unsigned long)INT_MAX) Using INT_MAX will allow using safe conversions between signed and unsigned integers. LONG_MAX seems cleaner regardless. -- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michał “mina86” Nazarewicz(o o) ooo +email/xmpp: m...@google.com--ooO--(_)--Ooo-- pgpMdROuCD0IG.pgp Description: PGP signature
Re: [PATCH 2/2] dma-buf: add helpers for attacher dma-parms
On 08/06/2012 01:58 PM, Michal Nazarewicz wrote: Tomasz Stanislawski t.stanisl...@samsung.com writes: I recommend to change the semantics for unlimited number of segments from 'value 0' to: #define DMA_SEGMENTS_COUNT_UNLIMITED ((unsigned long)INT_MAX) Sorry. It should be: #define DMA_SEGMENTS_COUNT_UNLIMITED ((unsigned int)INT_MAX) Using INT_MAX will allow using safe conversions between signed and unsigned integers. LONG_MAX seems cleaner regardless. -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/2] dma-buf: add helpers for attacher dma-parms
Fyi, Daniel Vetter had suggested on IRC that it would be cleaner to
have a single helper fxn that most-restrictive union of all attached
device's dma_parms. Really this should include dma_mask and
coherent_dma_mask, I think. But that touches a lot of other places in
the code. If no one objects to the cleanup of moving
dma_mask/coherent_dma_mask into dma_parms, I'll do this first.
So anyways, don't consider this patch yet for inclusion, I'll make an
updated one based on dma_parms..
BR,
-R
On Thu, Jul 19, 2012 at 11:23 AM, Rob Clark rob.cl...@linaro.org wrote:
From: Rob Clark r...@ti.com
Add some helpers to iterate through all attachers and get the most
restrictive segment size/count/boundary.
Signed-off-by: Rob Clark r...@ti.com
---
drivers/base/dma-buf.c | 63
+++
include/linux/dma-buf.h | 19 ++
2 files changed, 82 insertions(+)
diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index 24e88fe..757ee20 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -192,6 +192,69 @@ void dma_buf_put(struct dma_buf *dmabuf)
EXPORT_SYMBOL_GPL(dma_buf_put);
/**
+ * dma_buf_max_seg_size - helper for exporters to get the minimum of
+ * all attached device's max segment size
+ */
+unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach;
+ unsigned int max = (unsigned int)-1;
+
+ if (WARN_ON(!dmabuf))
+ return 0;
+
+ mutex_lock(dmabuf-lock);
+ list_for_each_entry(attach, dmabuf-attachments, node)
+ max = min(max, dma_get_max_seg_size(attach-dev));
+ mutex_unlock(dmabuf-lock);
+
+ return max;
+}
+EXPORT_SYMBOL_GPL(dma_buf_max_seg_size);
+
+/**
+ * dma_buf_max_seg_count - helper for exporters to get the minimum of
+ * all attached device's max segment count
+ */
+unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach;
+ unsigned int max = (unsigned int)-1;
+
+ if (WARN_ON(!dmabuf))
+ return 0;
+
+ mutex_lock(dmabuf-lock);
+ list_for_each_entry(attach, dmabuf-attachments, node)
+ max = min(max, dma_get_max_seg_count(attach-dev));
+ mutex_unlock(dmabuf-lock);
+
+ return max;
+}
+EXPORT_SYMBOL_GPL(dma_buf_max_seg_count);
+
+/**
+ * dma_buf_get_seg_boundary - helper for exporters to get the most
+ * restrictive segment alignment of all the attached devices
+ */
+unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach;
+ unsigned int mask = (unsigned int)-1;
+
+ if (WARN_ON(!dmabuf))
+ return 0;
+
+ mutex_lock(dmabuf-lock);
+ list_for_each_entry(attach, dmabuf-attachments, node)
+ mask = dma_get_seg_boundary(attach-dev);
+ mutex_unlock(dmabuf-lock);
+
+ return mask;
+}
+EXPORT_SYMBOL_GPL(dma_buf_get_seg_boundary);
+
+/**
* dma_buf_attach - Add the device to dma_buf's attachments list; optionally,
* calls attach() of dma_buf_ops to allow device-specific attach
functionality
* @dmabuf:[in]buffer to attach device to.
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index eb48f38..9533b9b 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -167,6 +167,10 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags);
struct dma_buf *dma_buf_get(int fd);
void dma_buf_put(struct dma_buf *dmabuf);
+unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf);
+unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf);
+unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf);
+
struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *,
enum dma_data_direction);
void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *,
@@ -220,6 +224,21 @@ static inline void dma_buf_put(struct dma_buf *dmabuf)
return;
}
+static inline unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf)
+{
+ return 0;
+}
+
+static inline unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf)
+{
+ return 0;
+}
+
+static inline unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf)
+{
+ return 0;
+}
+
static inline struct sg_table *dma_buf_map_attachment(
struct dma_buf_attachment *attach, enum dma_data_direction write)
{
--
1.7.9.5
--
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[PATCH 2/2] dma-buf: add helpers for attacher dma-parms
From: Rob Clark r...@ti.com
Add some helpers to iterate through all attachers and get the most
restrictive segment size/count/boundary.
Signed-off-by: Rob Clark r...@ti.com
---
drivers/base/dma-buf.c | 63 +++
include/linux/dma-buf.h | 19 ++
2 files changed, 82 insertions(+)
diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index 24e88fe..757ee20 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -192,6 +192,69 @@ void dma_buf_put(struct dma_buf *dmabuf)
EXPORT_SYMBOL_GPL(dma_buf_put);
/**
+ * dma_buf_max_seg_size - helper for exporters to get the minimum of
+ * all attached device's max segment size
+ */
+unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach;
+ unsigned int max = (unsigned int)-1;
+
+ if (WARN_ON(!dmabuf))
+ return 0;
+
+ mutex_lock(dmabuf-lock);
+ list_for_each_entry(attach, dmabuf-attachments, node)
+ max = min(max, dma_get_max_seg_size(attach-dev));
+ mutex_unlock(dmabuf-lock);
+
+ return max;
+}
+EXPORT_SYMBOL_GPL(dma_buf_max_seg_size);
+
+/**
+ * dma_buf_max_seg_count - helper for exporters to get the minimum of
+ * all attached device's max segment count
+ */
+unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach;
+ unsigned int max = (unsigned int)-1;
+
+ if (WARN_ON(!dmabuf))
+ return 0;
+
+ mutex_lock(dmabuf-lock);
+ list_for_each_entry(attach, dmabuf-attachments, node)
+ max = min(max, dma_get_max_seg_count(attach-dev));
+ mutex_unlock(dmabuf-lock);
+
+ return max;
+}
+EXPORT_SYMBOL_GPL(dma_buf_max_seg_count);
+
+/**
+ * dma_buf_get_seg_boundary - helper for exporters to get the most
+ * restrictive segment alignment of all the attached devices
+ */
+unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach;
+ unsigned int mask = (unsigned int)-1;
+
+ if (WARN_ON(!dmabuf))
+ return 0;
+
+ mutex_lock(dmabuf-lock);
+ list_for_each_entry(attach, dmabuf-attachments, node)
+ mask = dma_get_seg_boundary(attach-dev);
+ mutex_unlock(dmabuf-lock);
+
+ return mask;
+}
+EXPORT_SYMBOL_GPL(dma_buf_get_seg_boundary);
+
+/**
* dma_buf_attach - Add the device to dma_buf's attachments list; optionally,
* calls attach() of dma_buf_ops to allow device-specific attach functionality
* @dmabuf:[in]buffer to attach device to.
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index eb48f38..9533b9b 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -167,6 +167,10 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags);
struct dma_buf *dma_buf_get(int fd);
void dma_buf_put(struct dma_buf *dmabuf);
+unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf);
+unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf);
+unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf);
+
struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *,
enum dma_data_direction);
void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *,
@@ -220,6 +224,21 @@ static inline void dma_buf_put(struct dma_buf *dmabuf)
return;
}
+static inline unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf)
+{
+ return 0;
+}
+
+static inline unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf)
+{
+ return 0;
+}
+
+static inline unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf)
+{
+ return 0;
+}
+
static inline struct sg_table *dma_buf_map_attachment(
struct dma_buf_attachment *attach, enum dma_data_direction write)
{
--
1.7.9.5
--
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