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

From: Leonid Yegoshin
Date: Wed Oct 29 2014 - 21:49:04 EST


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 <Leonid.Yegoshin@xxxxxxxxxx>
---
.../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));


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