Re: [PATCH v4 3/6] of: fix size when dma-range is not used
On 02/02/2015 07:18 AM, Catalin Marinas wrote:
On Fri, Jan 30, 2015 at 06:06:27PM +, Murali Karicheri wrote:
On 01/28/2015 12:30 PM, Catalin Marinas wrote:
I think we can remove this check altogether (we leaved without it for a
while) but we need to add 1 when calculating the mask:
dev-coherent_dma_mask = min(DMA_BIT_MASK(32),
DMA_BIT_MASK(ilog2(size + 1)));
For Keystone, the dma_addr is to be taken care as well to determine the
mask. The above will not work.
This was discussed before (not on this thread) and dma_addr should not
affect the mask, it only affects the pfn offset.
Based on the discussion so far, this is the function I have come up with
incorporating the suggestions. Please review this and see if I have
missed out any. This works fine on Keystone.
void of_dma_configure(struct device *dev, struct device_node *np)
{
u64 dma_addr = 0, paddr, size;
int ret;
bool coherent;
unsigned long offset = 0;
struct iommu_ops *iommu;
/*
* Set default size to cover the 32-bit. Drivers are expected to setup
* the correct size and dma_mask.
*/
size = 1ULL 32;
ret = of_dma_get_range(np,dma_addr,paddr,size);
if (!ret) {
offset = PFN_DOWN(paddr - dma_addr);
if (!size) {
dev_err(dev, Invalid size (%llx)\n,
size);
return;
}
if (size 1) {
size = size + 1;
dev_warn(dev, Incorrect usage of size (%llx)\n,
size);
}
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
dev-dma_pfn_offset = offset;
/*
* Coherent DMA masks larger than 32-bit must be explicitly set by the
* driver.
*/
dev-coherent_dma_mask = min(DMA_BIT_MASK(32),
DMA_BIT_MASK(ilog2(dma_addr + size)));
That's not correct, coherent_dma_mask should still be calculated solely
based on size, not dma_addr.
Functions like swiotlb_dma_supported() use phys_to_dma() which on ARM
(32-bit) subtracts the dma_pfn_offset, so the mask based on size works
fine.
In the arm64 tree, we haven't taken dma_pfn_offset into account for
phys_to_dma() yet but if needed for a SoC, we'll add it.
Catalin,
The size based dma mask calculation itself can be a separate topic
patch. This series is adding important fix to get the PCI driver
functional and I would like to get this merged as soon as possible. I
also want to hear from Arnd about yout comment as we had discussed this
in the initial discussion of this patch series and 8/8 is essentially
added based on that discussion. I will add a simple check to catch and
warn the incorrect size setting in DT for dma-range as suggested by Rob
Herring and create a new patch to for size based mask calculation. I
will be sending v6 (expected to be merged soon) today and will work to
add a new patch. Before that we need to agree on what is the content of
the patch.
1. On keystone, DMA address start at 0x8000_ and DMA-able memory is
2G from the above base address. So without taking into account the
dma_addr, mask calculated will be 0x7fff_ where as we need that to
be 0x_ for keystone. So need to use this in the calculation.
2. W.r.t arm_pfn_offset, this was added to support Keystone as the DDR
physical address for LPAE startes at 0x8__ and the pfn offset is
calculated as the PFN of (0x8__ - 0x8000_) to do the dma
address to DDR address translation. I haven't looked at
swiotlb_dma_supported() but will do so.
Murali
--
Murali Karicheri
Linux Kernel, Texas Instruments
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Re: [PATCH v4 3/6] of: fix size when dma-range is not used
On Fri, Jan 30, 2015 at 06:06:27PM +, Murali Karicheri wrote:
On 01/28/2015 12:30 PM, Catalin Marinas wrote:
I think we can remove this check altogether (we leaved without it for a
while) but we need to add 1 when calculating the mask:
dev-coherent_dma_mask = min(DMA_BIT_MASK(32),
DMA_BIT_MASK(ilog2(size + 1)));
For Keystone, the dma_addr is to be taken care as well to determine the
mask. The above will not work.
This was discussed before (not on this thread) and dma_addr should not
affect the mask, it only affects the pfn offset.
Based on the discussion so far, this is the function I have come up with
incorporating the suggestions. Please review this and see if I have
missed out any. This works fine on Keystone.
void of_dma_configure(struct device *dev, struct device_node *np)
{
u64 dma_addr = 0, paddr, size;
int ret;
bool coherent;
unsigned long offset = 0;
struct iommu_ops *iommu;
/*
* Set default size to cover the 32-bit. Drivers are expected to setup
* the correct size and dma_mask.
*/
size = 1ULL 32;
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (!ret) {
offset = PFN_DOWN(paddr - dma_addr);
if (!size) {
dev_err(dev, Invalid size (%llx)\n,
size);
return;
}
if (size 1) {
size = size + 1;
dev_warn(dev, Incorrect usage of size (%llx)\n,
size);
}
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
dev-dma_pfn_offset = offset;
/*
* Coherent DMA masks larger than 32-bit must be explicitly set by the
* driver.
*/
dev-coherent_dma_mask = min(DMA_BIT_MASK(32),
DMA_BIT_MASK(ilog2(dma_addr + size)));
That's not correct, coherent_dma_mask should still be calculated solely
based on size, not dma_addr.
Functions like swiotlb_dma_supported() use phys_to_dma() which on ARM
(32-bit) subtracts the dma_pfn_offset, so the mask based on size works
fine.
In the arm64 tree, we haven't taken dma_pfn_offset into account for
phys_to_dma() yet but if needed for a SoC, we'll add it.
--
Catalin
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Re: [PATCH v4 3/6] of: fix size when dma-range is not used
On 02/02/2015 07:18 AM, Catalin Marinas wrote:
On Fri, Jan 30, 2015 at 06:06:27PM +, Murali Karicheri wrote:
On 01/28/2015 12:30 PM, Catalin Marinas wrote:
I think we can remove this check altogether (we leaved without it for a
while) but we need to add 1 when calculating the mask:
dev-coherent_dma_mask = min(DMA_BIT_MASK(32),
DMA_BIT_MASK(ilog2(size + 1)));
For Keystone, the dma_addr is to be taken care as well to determine the
mask. The above will not work.
This was discussed before (not on this thread) and dma_addr should not
affect the mask, it only affects the pfn offset.
Based on the discussion so far, this is the function I have come up with
incorporating the suggestions. Please review this and see if I have
missed out any. This works fine on Keystone.
void of_dma_configure(struct device *dev, struct device_node *np)
{
u64 dma_addr = 0, paddr, size;
int ret;
bool coherent;
unsigned long offset = 0;
struct iommu_ops *iommu;
/*
* Set default size to cover the 32-bit. Drivers are expected to setup
* the correct size and dma_mask.
*/
size = 1ULL 32;
ret = of_dma_get_range(np,dma_addr,paddr,size);
if (!ret) {
offset = PFN_DOWN(paddr - dma_addr);
if (!size) {
dev_err(dev, Invalid size (%llx)\n,
size);
return;
}
if (size 1) {
size = size + 1;
dev_warn(dev, Incorrect usage of size (%llx)\n,
size);
}
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
dev-dma_pfn_offset = offset;
/*
* Coherent DMA masks larger than 32-bit must be explicitly set by the
* driver.
*/
dev-coherent_dma_mask = min(DMA_BIT_MASK(32),
DMA_BIT_MASK(ilog2(dma_addr + size)));
That's not correct, coherent_dma_mask should still be calculated solely
based on size, not dma_addr.
Functions like swiotlb_dma_supported() use phys_to_dma() which on ARM
(32-bit) subtracts the dma_pfn_offset, so the mask based on size works
fine.
In the arm64 tree, we haven't taken dma_pfn_offset into account for
phys_to_dma() yet but if needed for a SoC, we'll add it.
I need to hear Arnd's comment on this. I am seeing an issue without this
change. Probably it needs a change else where. I will post the error I
am getting to this list.
Murali
--
Murali Karicheri
Linux Kernel, Texas Instruments
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Re: [PATCH v4 3/6] of: fix size when dma-range is not used
On Tue, Jan 27, 2015 at 06:55:15PM +, Murali Karicheri wrote:
On 01/27/2015 06:27 AM, Robin Murphy wrote:
On 23/01/15 22:32, Murali Karicheri wrote:
Fix the dma-range size when the DT attribute is missing. i.e set size to
dev-coherent_dma_mask + 1 instead of dev-coherent_dma_mask. To detect
overflow when mask is set to max of u64, add a check, log error and
return.
Some platform use mask format for size in DTS. So add a work around to
catch this and fix.
Cc: Joerg Roedel j...@8bytes.org
Cc: Grant Likely grant.lik...@linaro.org
Cc: Rob Herring robh...@kernel.org
Cc: Bjorn Helgaas bhelg...@google.com
Cc: Will Deacon will.dea...@arm.com
Cc: Russell King li...@arm.linux.org.uk
Cc: Arnd Bergmann a...@arndb.de
Cc: Suravee Suthikulpanit suravee.suthikulpa...@amd.com
Signed-off-by: Murali Karicheri m-kariche...@ti.com
---
drivers/of/device.c | 14 +-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 2de320d..0a5ff54 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -105,12 +105,24 @@ void of_dma_configure(struct device *dev, struct
device_node *np)
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
+ size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
+ /*
+ * Add a work around to treat the size as mask + 1 in case
+ * it is defined in DT as a mask.
+ */
+ if (size 1)
+ size = size + 1;
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
+ /* if size is 0, we have an overflow of u64 */
+ if (!size) {
+ dev_err(dev, invalid size\n);
+ return;
+ }
+
This seems potentially fragile to dodgy DTs given that we might also be
using size to make a mask later. Would it make sense to double-up a
sanity check as mask-format detection? Something like:
if is_power_of_2(size)
// use size
else if is_power_of_2(size + 1)
// use size + 1
else
// cry
How about having the logic like this?
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
if (is_power_of_2(size + 1))
size = size + 1;
else if (!is_power_of_2(size))
{
dev_err(dev, invalid size\n);
return;
}
In of_dma_configure(), we currently assume that the default coherent
mask is 32-bit. In this thread:
http://article.gmane.org/gmane.linux.kernel/1835096
we talked about setting the coherent mask based on size automatically.
I'm not sure about the size but I think we can assume is 32-bit mask + 1
if it is not specified in the DT. Instead of just assuming a default
mask, let's assume a default size and create the mask based on this
(untested):
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 5b33c6a21807..9ff8d1286b44 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -170,10 +170,10 @@ static void of_dma_configure(struct device *dev)
struct iommu_ops *iommu;
/*
-* Set default dma-mask to 32 bit. Drivers are expected to setup
-* the correct supported dma_mask.
+* Set default size to cover the 32-bit. Drivers are expected to setup
+* the correct size and dma_mask.
*/
- dev-coherent_dma_mask = DMA_BIT_MASK(32);
+ size = 1ULL 32;
/*
* Set it to coherent_dma_mask by default if the architecture
@@ -185,13 +185,24 @@ static void of_dma_configure(struct device *dev)
ret = of_dma_get_range(dev-of_node, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, dev-dma_pfn_offset);
}
dev-dma_pfn_offset = offset;
+ /*
+* Workaround for DTs setting the size to a mask or 0.
+*/
+ if (is_power_of_2(size + 1))
+ size += 1;
+
+ /*
+* Coherent DMA masks larger than 32-bit must be explicitly set by the
+* driver.
+*/
+ dev-coherent_dma_mask = min(DMA_BIT_MASK(32),
DMA_BIT_MASK(ilog2(size)));
+
coherent = of_dma_is_coherent(dev-of_node);
dev_dbg(dev, device is%sdma coherent\n,
coherent ? : not );
--
Catalin
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Re: [PATCH v4 3/6] of: fix size when dma-range is not used
On Wed, Jan 28, 2015 at 03:55:57PM +, Robin Murphy wrote:
On 28/01/15 11:05, Catalin Marinas wrote:
On Tue, Jan 27, 2015 at 06:55:15PM +, Murali Karicheri wrote:
How about having the logic like this?
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
if (is_power_of_2(size + 1))
size = size + 1;
else if (!is_power_of_2(size))
{
dev_err(dev, invalid size\n);
return;
}
In of_dma_configure(), we currently assume that the default coherent
mask is 32-bit. In this thread:
http://article.gmane.org/gmane.linux.kernel/1835096
we talked about setting the coherent mask based on size automatically.
I'm not sure about the size but I think we can assume is 32-bit mask + 1
if it is not specified in the DT. Instead of just assuming a default
mask, let's assume a default size and create the mask based on this
(untested):
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 5b33c6a21807..9ff8d1286b44 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -170,10 +170,10 @@ static void of_dma_configure(struct device *dev)
struct iommu_ops *iommu;
/*
-* Set default dma-mask to 32 bit. Drivers are expected to setup
-* the correct supported dma_mask.
+* Set default size to cover the 32-bit. Drivers are expected to setup
+* the correct size and dma_mask.
*/
- dev-coherent_dma_mask = DMA_BIT_MASK(32);
+ size = 1ULL 32;
/*
* Set it to coherent_dma_mask by default if the architecture
@@ -185,13 +185,24 @@ static void of_dma_configure(struct device *dev)
ret = of_dma_get_range(dev-of_node, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, dev-dma_pfn_offset);
}
dev-dma_pfn_offset = offset;
+ /*
+* Workaround for DTs setting the size to a mask or 0.
+*/
+ if (is_power_of_2(size + 1))
+ size += 1;
In fact, since the ilog2 below ends up effectively rounding down, we
might as well do away with this check as well and just add 1
unconditionally. The only time it makes any difference is when we want
it to anyway!
Well, we could simply ignore the is_power_of_2() check but without
incrementing size as we don't know what arch_setup_dma_ops() does with
it.
I think we can remove this check altogether (we leaved without it for a
while) but we need to add 1 when calculating the mask:
dev-coherent_dma_mask = min(DMA_BIT_MASK(32),
DMA_BIT_MASK(ilog2(size + 1)));
--
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Re: [PATCH v4 3/6] of: fix size when dma-range is not used
On 01/28/2015 10:45 AM, Rob Herring wrote:
On Wed, Jan 28, 2015 at 5:05 AM, Catalin Marinas
catalin.mari...@arm.com wrote:
On Tue, Jan 27, 2015 at 06:55:15PM +, Murali Karicheri wrote:
On 01/27/2015 06:27 AM, Robin Murphy wrote:
On 23/01/15 22:32, Murali Karicheri wrote:
Fix the dma-range size when the DT attribute is missing. i.e set size to
dev-coherent_dma_mask + 1 instead of dev-coherent_dma_mask. To detect
overflow when mask is set to max of u64, add a check, log error and
return.
Some platform use mask format for size in DTS. So add a work around to
catch this and fix.
Cc: Joerg Roedelj...@8bytes.org
Cc: Grant Likelygrant.lik...@linaro.org
Cc: Rob Herringrobh...@kernel.org
Cc: Bjorn Helgaasbhelg...@google.com
Cc: Will Deaconwill.dea...@arm.com
Cc: Russell Kingli...@arm.linux.org.uk
Cc: Arnd Bergmanna...@arndb.de
Cc: Suravee Suthikulpanitsuravee.suthikulpa...@amd.com
Signed-off-by: Murali Karicherim-kariche...@ti.com
---
drivers/of/device.c | 14 +-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 2de320d..0a5ff54 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -105,12 +105,24 @@ void of_dma_configure(struct device *dev, struct
device_node *np)
ret = of_dma_get_range(np,dma_addr,paddr,size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
+ size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
+ /*
+ * Add a work around to treat the size as mask + 1 in case
+ * it is defined in DT as a mask.
+ */
+ if (size 1)
+ size = size + 1;
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
+ /* if size is 0, we have an overflow of u64 */
+ if (!size) {
+ dev_err(dev, invalid size\n);
+ return;
+ }
+
This seems potentially fragile to dodgy DTs given that we might also be
using size to make a mask later. Would it make sense to double-up a
sanity check as mask-format detection? Something like:
if is_power_of_2(size)
// use size
else if is_power_of_2(size + 1)
// use size + 1
else
// cry
How about having the logic like this?
ret = of_dma_get_range(np,dma_addr,paddr,size);
if (ret 0) {
dma_addr = offset = 0;
size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
if (is_power_of_2(size + 1))
size = size + 1;
else if (!is_power_of_2(size))
{
dev_err(dev, invalid size\n);
return;
}
In of_dma_configure(), we currently assume that the default coherent
mask is 32-bit. In this thread:
http://article.gmane.org/gmane.linux.kernel/1835096
we talked about setting the coherent mask based on size automatically.
I'm not sure about the size but I think we can assume is 32-bit mask + 1
if it is not specified in the DT. Instead of just assuming a default
mask, let's assume a default size and create the mask based on this
(untested):
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 5b33c6a21807..9ff8d1286b44 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -170,10 +170,10 @@ static void of_dma_configure(struct device *dev)
struct iommu_ops *iommu;
/*
-* Set default dma-mask to 32 bit. Drivers are expected to setup
-* the correct supported dma_mask.
+* Set default size to cover the 32-bit. Drivers are expected to setup
+* the correct size and dma_mask.
*/
- dev-coherent_dma_mask = DMA_BIT_MASK(32);
+ size = 1ULL 32;
/*
* Set it to coherent_dma_mask by default if the architecture
@@ -185,13 +185,24 @@ static void of_dma_configure(struct device *dev)
ret = of_dma_get_range(dev-of_node,dma_addr,paddr,size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
Are we assuming dma_addr, paddr and size are not touched on error? If
so, we can get rid of this clause entirely.
Checking the code for of_dma_get_range() I see paddr is modified on
error case, but is used only for success case in this function. dma_addr
and size are not modified. So setting dma_addr and offset to zero before
hand like size might work as below
dma_addr = offset = 0;
size = 1ULL 32;
ret = of_dma_get_range(dev-of_node,dma_addr,paddr,size);
if (!ret) {
offset = PFN_DOWN(paddr - dma_addr);
}
.. rest of the code.
Murali
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, dev-dma_pfn_offset);
}
dev-dma_pfn_offset = offset;
+ /*
+* Workaround for DTs setting the size to a mask or 0.
+*/
+ if (is_power_of_2(size + 1))
+ size += 1;
As I mentioned, I think power of 2 is too restrictive (from a DT
perspective even though the kernel may
Re: [PATCH v4 3/6] of: fix size when dma-range is not used
On 28/01/15 11:05, Catalin Marinas wrote:
On Tue, Jan 27, 2015 at 06:55:15PM +, Murali Karicheri wrote:
On 01/27/2015 06:27 AM, Robin Murphy wrote:
On 23/01/15 22:32, Murali Karicheri wrote:
Fix the dma-range size when the DT attribute is missing. i.e set size to
dev-coherent_dma_mask + 1 instead of dev-coherent_dma_mask. To detect
overflow when mask is set to max of u64, add a check, log error and
return.
Some platform use mask format for size in DTS. So add a work around to
catch this and fix.
Cc: Joerg Roedel j...@8bytes.org
Cc: Grant Likely grant.lik...@linaro.org
Cc: Rob Herring robh...@kernel.org
Cc: Bjorn Helgaas bhelg...@google.com
Cc: Will Deacon will.dea...@arm.com
Cc: Russell King li...@arm.linux.org.uk
Cc: Arnd Bergmann a...@arndb.de
Cc: Suravee Suthikulpanit suravee.suthikulpa...@amd.com
Signed-off-by: Murali Karicheri m-kariche...@ti.com
---
drivers/of/device.c | 14 +-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 2de320d..0a5ff54 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -105,12 +105,24 @@ void of_dma_configure(struct device *dev, struct
device_node *np)
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
+ size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
+ /*
+ * Add a work around to treat the size as mask + 1 in case
+ * it is defined in DT as a mask.
+ */
+ if (size 1)
+ size = size + 1;
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
+ /* if size is 0, we have an overflow of u64 */
+ if (!size) {
+ dev_err(dev, invalid size\n);
+ return;
+ }
+
This seems potentially fragile to dodgy DTs given that we might also be
using size to make a mask later. Would it make sense to double-up a
sanity check as mask-format detection? Something like:
if is_power_of_2(size)
// use size
else if is_power_of_2(size + 1)
// use size + 1
else
// cry
How about having the logic like this?
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
if (is_power_of_2(size + 1))
size = size + 1;
else if (!is_power_of_2(size))
{
dev_err(dev, invalid size\n);
return;
}
In of_dma_configure(), we currently assume that the default coherent
mask is 32-bit. In this thread:
http://article.gmane.org/gmane.linux.kernel/1835096
we talked about setting the coherent mask based on size automatically.
I'm not sure about the size but I think we can assume is 32-bit mask + 1
if it is not specified in the DT. Instead of just assuming a default
mask, let's assume a default size and create the mask based on this
(untested):
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 5b33c6a21807..9ff8d1286b44 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -170,10 +170,10 @@ static void of_dma_configure(struct device *dev)
struct iommu_ops *iommu;
/*
-* Set default dma-mask to 32 bit. Drivers are expected to setup
-* the correct supported dma_mask.
+* Set default size to cover the 32-bit. Drivers are expected to setup
+* the correct size and dma_mask.
*/
- dev-coherent_dma_mask = DMA_BIT_MASK(32);
+ size = 1ULL 32;
/*
* Set it to coherent_dma_mask by default if the architecture
@@ -185,13 +185,24 @@ static void of_dma_configure(struct device *dev)
ret = of_dma_get_range(dev-of_node, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, dev-dma_pfn_offset);
}
dev-dma_pfn_offset = offset;
+ /*
+* Workaround for DTs setting the size to a mask or 0.
+*/
+ if (is_power_of_2(size + 1))
+ size += 1;
In fact, since the ilog2 below ends up effectively rounding down, we
might as well do away with this check as well and just add 1
unconditionally. The only time it makes any difference is when we want
it to anyway!
I like this approach, it ends up looking a lot neater.
Robin.
+
+ /*
+* Coherent DMA masks larger than 32-bit must be explicitly set by the
+* driver.
+*/
+ dev-coherent_dma_mask = min(DMA_BIT_MASK(32),
DMA_BIT_MASK(ilog2(size)));
+
coherent = of_dma_is_coherent(dev-of_node);
dev_dbg(dev, device is%sdma coherent\n,
coherent ? : not );
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Re: [PATCH v4 3/6] of: fix size when dma-range is not used
On Wed, Jan 28, 2015 at 5:05 AM, Catalin Marinas
catalin.mari...@arm.com wrote:
On Tue, Jan 27, 2015 at 06:55:15PM +, Murali Karicheri wrote:
On 01/27/2015 06:27 AM, Robin Murphy wrote:
On 23/01/15 22:32, Murali Karicheri wrote:
Fix the dma-range size when the DT attribute is missing. i.e set size to
dev-coherent_dma_mask + 1 instead of dev-coherent_dma_mask. To detect
overflow when mask is set to max of u64, add a check, log error and
return.
Some platform use mask format for size in DTS. So add a work around to
catch this and fix.
Cc: Joerg Roedel j...@8bytes.org
Cc: Grant Likely grant.lik...@linaro.org
Cc: Rob Herring robh...@kernel.org
Cc: Bjorn Helgaas bhelg...@google.com
Cc: Will Deacon will.dea...@arm.com
Cc: Russell King li...@arm.linux.org.uk
Cc: Arnd Bergmann a...@arndb.de
Cc: Suravee Suthikulpanit suravee.suthikulpa...@amd.com
Signed-off-by: Murali Karicheri m-kariche...@ti.com
---
drivers/of/device.c | 14 +-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 2de320d..0a5ff54 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -105,12 +105,24 @@ void of_dma_configure(struct device *dev, struct
device_node *np)
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
+ size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
+ /*
+ * Add a work around to treat the size as mask + 1 in case
+ * it is defined in DT as a mask.
+ */
+ if (size 1)
+ size = size + 1;
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
+ /* if size is 0, we have an overflow of u64 */
+ if (!size) {
+ dev_err(dev, invalid size\n);
+ return;
+ }
+
This seems potentially fragile to dodgy DTs given that we might also be
using size to make a mask later. Would it make sense to double-up a
sanity check as mask-format detection? Something like:
if is_power_of_2(size)
// use size
else if is_power_of_2(size + 1)
// use size + 1
else
// cry
How about having the logic like this?
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
if (is_power_of_2(size + 1))
size = size + 1;
else if (!is_power_of_2(size))
{
dev_err(dev, invalid size\n);
return;
}
In of_dma_configure(), we currently assume that the default coherent
mask is 32-bit. In this thread:
http://article.gmane.org/gmane.linux.kernel/1835096
we talked about setting the coherent mask based on size automatically.
I'm not sure about the size but I think we can assume is 32-bit mask + 1
if it is not specified in the DT. Instead of just assuming a default
mask, let's assume a default size and create the mask based on this
(untested):
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 5b33c6a21807..9ff8d1286b44 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -170,10 +170,10 @@ static void of_dma_configure(struct device *dev)
struct iommu_ops *iommu;
/*
-* Set default dma-mask to 32 bit. Drivers are expected to setup
-* the correct supported dma_mask.
+* Set default size to cover the 32-bit. Drivers are expected to setup
+* the correct size and dma_mask.
*/
- dev-coherent_dma_mask = DMA_BIT_MASK(32);
+ size = 1ULL 32;
/*
* Set it to coherent_dma_mask by default if the architecture
@@ -185,13 +185,24 @@ static void of_dma_configure(struct device *dev)
ret = of_dma_get_range(dev-of_node, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
Are we assuming dma_addr, paddr and size are not touched on error? If
so, we can get rid of this clause entirely.
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, dev-dma_pfn_offset);
}
dev-dma_pfn_offset = offset;
+ /*
+* Workaround for DTs setting the size to a mask or 0.
+*/
+ if (is_power_of_2(size + 1))
+ size += 1;
As I mentioned, I think power of 2 is too restrictive (from a DT
perspective even though the kernel may require a power of 2 here for
the mask). Just checking bit0 set should be enough.
Also, we need a WARN here so DTs get fixed.
+
+ /*
+* Coherent DMA masks larger than 32-bit must be explicitly set by the
+* driver.
+*/
+ dev-coherent_dma_mask = min(DMA_BIT_MASK(32),
DMA_BIT_MASK(ilog2(size)));
Re: [PATCH v4 3/6] of: fix size when dma-range is not used
On Wed, Jan 28, 2015 at 03:45:19PM +, Rob Herring wrote:
On Wed, Jan 28, 2015 at 5:05 AM, Catalin Marinas
catalin.mari...@arm.com wrote:
On Tue, Jan 27, 2015 at 06:55:15PM +, Murali Karicheri wrote:
How about having the logic like this?
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
if (is_power_of_2(size + 1))
size = size + 1;
else if (!is_power_of_2(size))
{
dev_err(dev, invalid size\n);
return;
}
In of_dma_configure(), we currently assume that the default coherent
mask is 32-bit. In this thread:
http://article.gmane.org/gmane.linux.kernel/1835096
we talked about setting the coherent mask based on size automatically.
I'm not sure about the size but I think we can assume is 32-bit mask + 1
if it is not specified in the DT. Instead of just assuming a default
mask, let's assume a default size and create the mask based on this
(untested):
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 5b33c6a21807..9ff8d1286b44 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -170,10 +170,10 @@ static void of_dma_configure(struct device *dev)
struct iommu_ops *iommu;
/*
-* Set default dma-mask to 32 bit. Drivers are expected to setup
-* the correct supported dma_mask.
+* Set default size to cover the 32-bit. Drivers are expected to
setup
+* the correct size and dma_mask.
*/
- dev-coherent_dma_mask = DMA_BIT_MASK(32);
+ size = 1ULL 32;
/*
* Set it to coherent_dma_mask by default if the architecture
@@ -185,13 +185,24 @@ static void of_dma_configure(struct device *dev)
ret = of_dma_get_range(dev-of_node, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
Are we assuming dma_addr, paddr and size are not touched on error? If
so, we can get rid of this clause entirely.
We can if we initialise dma_addr and offset to 0 when declared in this
function. The dma_addr and size variables are later passed to the
arch_setup_dma_ops(), so they need to have some sane values independent
of the presence of dma-ranges in the DT.
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n,
dev-dma_pfn_offset);
}
dev-dma_pfn_offset = offset;
+ /*
+* Workaround for DTs setting the size to a mask or 0.
+*/
+ if (is_power_of_2(size + 1))
+ size += 1;
As I mentioned, I think power of 2 is too restrictive (from a DT
perspective even though the kernel may require a power of 2 here for
the mask). Just checking bit0 set should be enough.
The power of 2 was mainly to cover the case where the size is wrongly
written as a mask in the DT. If the size is deliberately not a power of
two and not a full mask, the above check won't change it. With my
proposal, ilog2 gets rid of extra bits in size, only that if the size
was a mask because of DT error, we lose a bit in the coherent_dma_mask.
Also, we need a WARN here so DTs get fixed.
I agree.
--
Catalin
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Re: [PATCH v4 3/6] of: fix size when dma-range is not used
On 01/27/2015 06:27 AM, Robin Murphy wrote:
Hi Murali,
On 23/01/15 22:32, Murali Karicheri wrote:
Fix the dma-range size when the DT attribute is missing. i.e set size to
dev-coherent_dma_mask + 1 instead of dev-coherent_dma_mask. To detect
overflow when mask is set to max of u64, add a check, log error and
return.
Some platform use mask format for size in DTS. So add a work around to
catch this and fix.
Cc: Joerg Roedel j...@8bytes.org
Cc: Grant Likely grant.lik...@linaro.org
Cc: Rob Herring robh...@kernel.org
Cc: Bjorn Helgaas bhelg...@google.com
Cc: Will Deacon will.dea...@arm.com
Cc: Russell King li...@arm.linux.org.uk
Cc: Arnd Bergmann a...@arndb.de
Cc: Suravee Suthikulpanit suravee.suthikulpa...@amd.com
Signed-off-by: Murali Karicheri m-kariche...@ti.com
---
drivers/of/device.c | 14 +-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 2de320d..0a5ff54 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -105,12 +105,24 @@ void of_dma_configure(struct device *dev, struct
device_node *np)
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
+ size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
+ /*
+ * Add a work around to treat the size as mask + 1 in case
+ * it is defined in DT as a mask.
+ */
+ if (size 1)
+ size = size + 1;
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
+ /* if size is 0, we have an overflow of u64 */
+ if (!size) {
+ dev_err(dev, invalid size\n);
+ return;
+ }
+
This seems potentially fragile to dodgy DTs given that we might also be
using size to make a mask later. Would it make sense to double-up a
sanity check as mask-format detection? Something like:
if is_power_of_2(size)
// use size
else if is_power_of_2(size + 1)
// use size + 1
else
// cry
Robin,
How about having the logic like this?
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
if (is_power_of_2(size + 1))
size = size + 1;
else if (!is_power_of_2(size))
{
dev_err(dev, invalid size\n);
return;
}
Murali
Robin.
dev-dma_pfn_offset = offset;
coherent = of_dma_is_coherent(np);
--
Murali Karicheri
Linux Kernel, Texas Instruments
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Re: [PATCH v4 3/6] of: fix size when dma-range is not used
Hi Murali,
On 23/01/15 22:32, Murali Karicheri wrote:
Fix the dma-range size when the DT attribute is missing. i.e set size to
dev-coherent_dma_mask + 1 instead of dev-coherent_dma_mask. To detect
overflow when mask is set to max of u64, add a check, log error and return.
Some platform use mask format for size in DTS. So add a work around to
catch this and fix.
Cc: Joerg Roedel j...@8bytes.org
Cc: Grant Likely grant.lik...@linaro.org
Cc: Rob Herring robh...@kernel.org
Cc: Bjorn Helgaas bhelg...@google.com
Cc: Will Deacon will.dea...@arm.com
Cc: Russell King li...@arm.linux.org.uk
Cc: Arnd Bergmann a...@arndb.de
Cc: Suravee Suthikulpanit suravee.suthikulpa...@amd.com
Signed-off-by: Murali Karicheri m-kariche...@ti.com
---
drivers/of/device.c | 14 +-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 2de320d..0a5ff54 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -105,12 +105,24 @@ void of_dma_configure(struct device *dev, struct
device_node *np)
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
+ size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
+ /*
+* Add a work around to treat the size as mask + 1 in case
+* it is defined in DT as a mask.
+*/
+ if (size 1)
+ size = size + 1;
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
+ /* if size is 0, we have an overflow of u64 */
+ if (!size) {
+ dev_err(dev, invalid size\n);
+ return;
+ }
+
This seems potentially fragile to dodgy DTs given that we might also be
using size to make a mask later. Would it make sense to double-up a
sanity check as mask-format detection? Something like:
if is_power_of_2(size)
// use size
else if is_power_of_2(size + 1)
// use size + 1
else
// cry
Robin.
dev-dma_pfn_offset = offset;
coherent = of_dma_is_coherent(np);
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Re: [PATCH v4 3/6] of: fix size when dma-range is not used
On 01/27/2015 06:27 AM, Robin Murphy wrote:
Hi Murali,
On 23/01/15 22:32, Murali Karicheri wrote:
Fix the dma-range size when the DT attribute is missing. i.e set size to
dev-coherent_dma_mask + 1 instead of dev-coherent_dma_mask. To detect
overflow when mask is set to max of u64, add a check, log error and
return.
Some platform use mask format for size in DTS. So add a work around to
catch this and fix.
Cc: Joerg Roedel j...@8bytes.org
Cc: Grant Likely grant.lik...@linaro.org
Cc: Rob Herring robh...@kernel.org
Cc: Bjorn Helgaas bhelg...@google.com
Cc: Will Deacon will.dea...@arm.com
Cc: Russell King li...@arm.linux.org.uk
Cc: Arnd Bergmann a...@arndb.de
Cc: Suravee Suthikulpanit suravee.suthikulpa...@amd.com
Signed-off-by: Murali Karicheri m-kariche...@ti.com
---
drivers/of/device.c | 14 +-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 2de320d..0a5ff54 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -105,12 +105,24 @@ void of_dma_configure(struct device *dev, struct
device_node *np)
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
+ size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
+ /*
+ * Add a work around to treat the size as mask + 1 in case
+ * it is defined in DT as a mask.
+ */
+ if (size 1)
+ size = size + 1;
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
+ /* if size is 0, we have an overflow of u64 */
+ if (!size) {
+ dev_err(dev, invalid size\n);
+ return;
+ }
+
This seems potentially fragile to dodgy DTs given that we might also be
using size to make a mask later. Would it make sense to double-up a
sanity check as mask-format detection? Something like:
if is_power_of_2(size)
// use size
else if is_power_of_2(size + 1)
// use size + 1
else
// cry
Robin,
I think this is better. I will wait for some more time for anyone to
respond and re-send my patch with this change.
Thanks
Murali
Robin.
dev-dma_pfn_offset = offset;
coherent = of_dma_is_coherent(np);
--
Murali Karicheri
Linux Kernel, Texas Instruments
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[PATCH v4 3/6] of: fix size when dma-range is not used
Fix the dma-range size when the DT attribute is missing. i.e set size to
dev-coherent_dma_mask + 1 instead of dev-coherent_dma_mask. To detect
overflow when mask is set to max of u64, add a check, log error and return.
Some platform use mask format for size in DTS. So add a work around to
catch this and fix.
Cc: Joerg Roedel j...@8bytes.org
Cc: Grant Likely grant.lik...@linaro.org
Cc: Rob Herring robh...@kernel.org
Cc: Bjorn Helgaas bhelg...@google.com
Cc: Will Deacon will.dea...@arm.com
Cc: Russell King li...@arm.linux.org.uk
Cc: Arnd Bergmann a...@arndb.de
Cc: Suravee Suthikulpanit suravee.suthikulpa...@amd.com
Signed-off-by: Murali Karicheri m-kariche...@ti.com
---
drivers/of/device.c | 14 +-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 2de320d..0a5ff54 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -105,12 +105,24 @@ void of_dma_configure(struct device *dev, struct
device_node *np)
ret = of_dma_get_range(np, dma_addr, paddr, size);
if (ret 0) {
dma_addr = offset = 0;
- size = dev-coherent_dma_mask;
+ size = dev-coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
+ /*
+* Add a work around to treat the size as mask + 1 in case
+* it is defined in DT as a mask.
+*/
+ if (size 1)
+ size = size + 1;
dev_dbg(dev, dma_pfn_offset(%#08lx)\n, offset);
}
+ /* if size is 0, we have an overflow of u64 */
+ if (!size) {
+ dev_err(dev, invalid size\n);
+ return;
+ }
+
dev-dma_pfn_offset = offset;
coherent = of_dma_is_coherent(np);
--
1.7.9.5
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