2014-10-30 01:48:59

by Leonid Yegoshin

[permalink] [raw]
Subject: [PATCH] MIPS: DMA: fix coherent alloc in non-coherent systems

A default dma_alloc_coherent() fails to alloc a coherent memory on non-coherent
systems in case of device->coherent_dma_mask covering the whole memory space.

In case of non-coherent systems the coherent memory on MIPS is restricted by
size of un-cachable segment and should be located in ZONE_DMA.

Added __GFP_DMA flag in case of non-coherent systems to enforce an allocation
of coherent memory in ZONE_DMA.

Signed-off-by: Leonid Yegoshin <[email protected]>
---
.../include/asm/mach-cavium-octeon/dma-coherence.h | 2 +-
arch/mips/include/asm/mach-generic/dma-coherence.h | 2 +-
arch/mips/include/asm/mach-ip27/dma-coherence.h | 2 +-
arch/mips/include/asm/mach-ip32/dma-coherence.h | 2 +-
arch/mips/include/asm/mach-jazz/dma-coherence.h | 2 +-
.../mips/include/asm/mach-loongson/dma-coherence.h | 2 +-
arch/mips/mm/dma-default.c | 11 ++++++++---
7 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h b/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
index f9f4486..fe0b465 100644
--- a/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
+++ b/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
@@ -52,7 +52,7 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
return 0;
}

-static inline int plat_device_is_coherent(struct device *dev)
+static inline int plat_device_is_coherent(const struct device *dev)
{
return 1;
}
diff --git a/arch/mips/include/asm/mach-generic/dma-coherence.h b/arch/mips/include/asm/mach-generic/dma-coherence.h
index b4563df..2283996 100644
--- a/arch/mips/include/asm/mach-generic/dma-coherence.h
+++ b/arch/mips/include/asm/mach-generic/dma-coherence.h
@@ -47,7 +47,7 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
return 1;
}

-static inline int plat_device_is_coherent(struct device *dev)
+static inline int plat_device_is_coherent(const struct device *dev)
{
#ifdef CONFIG_DMA_COHERENT
return 1;
diff --git a/arch/mips/include/asm/mach-ip27/dma-coherence.h b/arch/mips/include/asm/mach-ip27/dma-coherence.h
index 4ffddfd..c7767e3 100644
--- a/arch/mips/include/asm/mach-ip27/dma-coherence.h
+++ b/arch/mips/include/asm/mach-ip27/dma-coherence.h
@@ -58,7 +58,7 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
return 1;
}

-static inline int plat_device_is_coherent(struct device *dev)
+static inline int plat_device_is_coherent(const struct device *dev)
{
return 1; /* IP27 non-cohernet mode is unsupported */
}
diff --git a/arch/mips/include/asm/mach-ip32/dma-coherence.h b/arch/mips/include/asm/mach-ip32/dma-coherence.h
index 104cfbc..a6b6a55 100644
--- a/arch/mips/include/asm/mach-ip32/dma-coherence.h
+++ b/arch/mips/include/asm/mach-ip32/dma-coherence.h
@@ -80,7 +80,7 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
return 1;
}

-static inline int plat_device_is_coherent(struct device *dev)
+static inline int plat_device_is_coherent(const struct device *dev)
{
return 0; /* IP32 is non-cohernet */
}
diff --git a/arch/mips/include/asm/mach-jazz/dma-coherence.h b/arch/mips/include/asm/mach-jazz/dma-coherence.h
index 949003e..57c1a6c 100644
--- a/arch/mips/include/asm/mach-jazz/dma-coherence.h
+++ b/arch/mips/include/asm/mach-jazz/dma-coherence.h
@@ -48,7 +48,7 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
return 1;
}

-static inline int plat_device_is_coherent(struct device *dev)
+static inline int plat_device_is_coherent(const struct device *dev)
{
return 0;
}
diff --git a/arch/mips/include/asm/mach-loongson/dma-coherence.h b/arch/mips/include/asm/mach-loongson/dma-coherence.h
index 6a90275..555d21b 100644
--- a/arch/mips/include/asm/mach-loongson/dma-coherence.h
+++ b/arch/mips/include/asm/mach-loongson/dma-coherence.h
@@ -69,7 +69,7 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
return 1;
}

-static inline int plat_device_is_coherent(struct device *dev)
+static inline int plat_device_is_coherent(const struct device *dev)
{
#ifdef CONFIG_DMA_NONCOHERENT
return 0;
diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index 42c819a..36e2237 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -69,7 +69,7 @@ static inline int cpu_needs_post_dma_flush(struct device *dev)
boot_cpu_type() == CPU_BMIPS5000);
}

-static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)
+static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp, int coherent)
{
gfp_t dma_flag;

@@ -81,6 +81,11 @@ static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)
dma_flag = __GFP_DMA;
else
#endif
+#ifdef CONFIG_ZONE_DMA
+ if (coherent && !plat_device_is_coherent(dev))
+ dma_flag = __GFP_DMA;
+ else
+#endif
#if defined(CONFIG_ZONE_DMA32) && defined(CONFIG_ZONE_DMA)
if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
dma_flag = __GFP_DMA;
@@ -111,7 +116,7 @@ void *dma_alloc_noncoherent(struct device *dev, size_t size,
{
void *ret;

- gfp = massage_gfp_flags(dev, gfp);
+ gfp = massage_gfp_flags(dev, gfp, 0);

ret = (void *) __get_free_pages(gfp, get_order(size));

@@ -132,7 +137,7 @@ static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
return ret;

- gfp = massage_gfp_flags(dev, gfp);
+ gfp = massage_gfp_flags(dev, gfp, 1);

ret = (void *) __get_free_pages(gfp, get_order(size));


2014-10-30 09:48:30

by Markos Chandras

[permalink] [raw]
Subject: Re: [PATCH] MIPS: DMA: fix coherent alloc in non-coherent systems

Hi,

On 10/30/2014 01:48 AM, Leonid Yegoshin wrote:
> A default dma_alloc_coherent() fails to alloc a coherent memory on non-coherent
> systems in case of device->coherent_dma_mask covering the whole memory space.
>
> In case of non-coherent systems the coherent memory on MIPS is restricted by
> size of un-cachable segment and should be located in ZONE_DMA.
>
> Added __GFP_DMA flag in case of non-coherent systems to enforce an allocation
> of coherent memory in ZONE_DMA.
>
> Signed-off-by: Leonid Yegoshin <[email protected]>
> ---
> .../include/asm/mach-cavium-octeon/dma-coherence.h | 2 +-
> arch/mips/include/asm/mach-generic/dma-coherence.h | 2 +-
> arch/mips/include/asm/mach-ip27/dma-coherence.h | 2 +-
> arch/mips/include/asm/mach-ip32/dma-coherence.h | 2 +-
> arch/mips/include/asm/mach-jazz/dma-coherence.h | 2 +-
> .../mips/include/asm/mach-loongson/dma-coherence.h | 2 +-
> arch/mips/mm/dma-default.c | 11 ++++++++---
> 7 files changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h b/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
> index f9f4486..fe0b465 100644
> --- a/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
> +++ b/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
> @@ -52,7 +52,7 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
> return 0;
> }
>
> -static inline int plat_device_is_coherent(struct device *dev)
> +static inline int plat_device_is_coherent(const struct device *dev)

Why adding const here?

> {
> return 1;
> }
> diff --git a/arch/mips/include/asm/mach-generic/dma-coherence.h b/arch/mips/include/asm/mach-generic/dma-coherence.h
> index b4563df..2283996 100644
> --- a/arch/mips/include/asm/mach-generic/dma-coherence.h
> +++ b/arch/mips/include/asm/mach-generic/dma-coherence.h
> @@ -47,7 +47,7 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
> return 1;
> }
>
> -static inline int plat_device_is_coherent(struct device *dev)
> +static inline int plat_device_is_coherent(const struct device *dev)

likewise

> {
> #ifdef CONFIG_DMA_COHERENT
> return 1;
> diff --git a/arch/mips/include/asm/mach-ip27/dma-coherence.h b/arch/mips/include/asm/mach-ip27/dma-coherence.h
> index 4ffddfd..c7767e3 100644
> --- a/arch/mips/include/asm/mach-ip27/dma-coherence.h
> +++ b/arch/mips/include/asm/mach-ip27/dma-coherence.h
> @@ -58,7 +58,7 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
> return 1;
> }
>
> -static inline int plat_device_is_coherent(struct device *dev)
> +static inline int plat_device_is_coherent(const struct device *dev)

likewise

> {
> return 1; /* IP27 non-cohernet mode is unsupported */
> }
> diff --git a/arch/mips/include/asm/mach-ip32/dma-coherence.h b/arch/mips/include/asm/mach-ip32/dma-coherence.h
> index 104cfbc..a6b6a55 100644
> --- a/arch/mips/include/asm/mach-ip32/dma-coherence.h
> +++ b/arch/mips/include/asm/mach-ip32/dma-coherence.h
> @@ -80,7 +80,7 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
> return 1;
> }
>
> -static inline int plat_device_is_coherent(struct device *dev)
> +static inline int plat_device_is_coherent(const struct device *dev)

likewise etc

Is it just a matter of consistence with the rest of the interfaces? Do
you need to move these into a separate patch since they don't quite fit
here.

--
markos

2014-10-30 09:51:45

by James Hogan

[permalink] [raw]
Subject: Re: [PATCH] MIPS: DMA: fix coherent alloc in non-coherent systems

Hi Markos,

On 30/10/14 09:48, Markos Chandras wrote:
>> diff --git a/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h b/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
>> index f9f4486..fe0b465 100644
>> --- a/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
>> +++ b/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
>> @@ -52,7 +52,7 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
>> return 0;
>> }
>>
>> -static inline int plat_device_is_coherent(struct device *dev)
>> +static inline int plat_device_is_coherent(const struct device *dev)
>
> Why adding const here?
>

<snip>

> Is it just a matter of consistence with the rest of the interfaces? Do
> you need to move these into a separate patch since they don't quite fit
> here.

See the new new call to plat_device_is_coherent(), which passes dev,
which is const.

Cheers
James

2014-10-30 09:54:11

by Markos Chandras

[permalink] [raw]
Subject: Re: [PATCH] MIPS: DMA: fix coherent alloc in non-coherent systems

On 10/30/2014 09:51 AM, James Hogan wrote:
> Hi Markos,
>
> On 30/10/14 09:48, Markos Chandras wrote:
>>> diff --git a/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h b/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
>>> index f9f4486..fe0b465 100644
>>> --- a/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
>>> +++ b/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
>>> @@ -52,7 +52,7 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
>>> return 0;
>>> }
>>>
>>> -static inline int plat_device_is_coherent(struct device *dev)
>>> +static inline int plat_device_is_coherent(const struct device *dev)
>>
>> Why adding const here?
>>
>
> <snip>
>
>> Is it just a matter of consistence with the rest of the interfaces? Do
>> you need to move these into a separate patch since they don't quite fit
>> here.
>
> See the new new call to plat_device_is_coherent(), which passes dev,
> which is const.
>
> Cheers
> James
>
Ah yes you are right. Thanks!

--
markos

2014-10-30 10:07:36

by James Hogan

[permalink] [raw]
Subject: Re: [PATCH] MIPS: DMA: fix coherent alloc in non-coherent systems

Hi Leonid,

On 30/10/14 01:48, Leonid Yegoshin wrote:
> A default dma_alloc_coherent() fails to alloc a coherent memory on non-coherent
> systems in case of device->coherent_dma_mask covering the whole memory space.
>
> In case of non-coherent systems the coherent memory on MIPS is restricted by
> size of un-cachable segment and should be located in ZONE_DMA.

Has this pretty much always been broken?

> @@ -81,6 +81,11 @@ static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)
> dma_flag = __GFP_DMA;
> else
> #endif
> +#ifdef CONFIG_ZONE_DMA
> + if (coherent && !plat_device_is_coherent(dev))

Broken indentation. Please fix to use tabs.

> + dma_flag = __GFP_DMA;
> + else
> +#endif
> #if defined(CONFIG_ZONE_DMA32) && defined(CONFIG_ZONE_DMA)
> if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
> dma_flag = __GFP_DMA;

Other than that, this patch looks okay to me (but those with more
experience with MIPS DMA than me may know better).

Reviewed-by: James Hogan <[email protected]>

Thanks
James

2014-10-30 18:38:20

by Leonid Yegoshin

[permalink] [raw]
Subject: Re: [PATCH] MIPS: DMA: fix coherent alloc in non-coherent systems

On 10/30/2014 03:07 AM, James Hogan wrote:
> Hi Leonid,
>
> On 30/10/14 01:48, Leonid Yegoshin wrote:
>> A default dma_alloc_coherent() fails to alloc a coherent memory on non-coherent
>> systems in case of device->coherent_dma_mask covering the whole memory space.
>>
>> In case of non-coherent systems the coherent memory on MIPS is restricted by
>> size of un-cachable segment and should be located in ZONE_DMA.
> Has this pretty much always been broken?
>
>
Yes, but it can be seen on MIPS32 EVA-based CPUs.