[PATCH/RFC 1/4] dma-mapping: Make arch_setup_dma_ops return an error code

From: Laura Abbott
Date: Thu Feb 05 2015 - 19:32:38 EST


Setting up the DMA operations may trigger a probe deferral.
Return a proper error code to let probe deferral do its thing.

Signed-off-by: Laura Abbott <lauraa@xxxxxxxxxxxxxx>
---
arch/arm/include/asm/dma-mapping.h | 2 +-
arch/arm/mm/dma-mapping.c | 4 +++-
arch/arm64/include/asm/dma-mapping.h | 2 +-
arch/arm64/mm/dma-mapping.c | 16 ++++++++++------
include/linux/dma-mapping.h | 7 +++++--
5 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index b52101d..68bff4e 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -122,7 +122,7 @@ static inline unsigned long dma_max_pfn(struct device *dev)
#define dma_max_pfn(dev) dma_max_pfn(dev)

#define arch_setup_dma_ops arch_setup_dma_ops
-extern void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+extern int arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
struct iommu_ops *iommu, bool coherent);

#define arch_teardown_dma_ops arch_teardown_dma_ops
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7864797..ba20196 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -2048,7 +2048,7 @@ static struct dma_map_ops *arm_get_dma_map_ops(bool coherent)
return coherent ? &arm_coherent_dma_ops : &arm_dma_ops;
}

-void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+int arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
struct iommu_ops *iommu, bool coherent)
{
struct dma_map_ops *dma_ops;
@@ -2060,6 +2060,8 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
dma_ops = arm_get_dma_map_ops(coherent);

set_dma_ops(dev, dma_ops);
+
+ return 0;
}

void arch_teardown_dma_ops(struct device *dev)
diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h
index 0791a78..f7968af 100644
--- a/arch/arm64/include/asm/dma-mapping.h
+++ b/arch/arm64/include/asm/dma-mapping.h
@@ -45,7 +45,7 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev)
return __generic_dma_ops(dev);
}

-void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+int arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
struct iommu_ops *iommu, bool coherent);
#define arch_setup_dma_ops arch_setup_dma_ops

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index d52175d..1e3c8f9 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -704,22 +704,24 @@ static struct dma_map_ops iommu_dma_ops = {
.mapping_error = iommu_dma_mapping_error,
};

-static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+static int __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
struct iommu_ops *ops)
{
struct iommu_dma_mapping *mapping;
+ int ret;

if (!ops)
- return;
+ return 0;

mapping = iommu_dma_create_mapping(ops, dma_base, size);
if (!mapping) {
pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",
size, dev_name(dev));
- return;
+ return -EINVAL;
}

- if (iommu_dma_attach_device(dev, mapping))
+ ret = iommu_dma_attach_device(dev, mapping);
+ if (ret)
pr_warn("Failed to attach device %s to IOMMU mapping\n",
dev_name(dev));
else
@@ -727,6 +729,8 @@ static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,

/* drop the initial mapping refcount */
iommu_dma_release_mapping(mapping);
+
+ return ret;
}

static void __iommu_teardown_dma_ops(struct device *dev)
@@ -747,11 +751,11 @@ static void __iommu_teardown_dma_ops(struct device *dev) { }

#endif /* CONFIG_IOMMU_DMA */

-void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+int arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
struct iommu_ops *iommu, bool coherent)
{
dev->archdata.dma_coherent = coherent;
- __iommu_setup_dma_ops(dev, dma_base, size, iommu);
+ return __iommu_setup_dma_ops(dev, dma_base, size, iommu);
}

void arch_teardown_dma_ops(struct device *dev)
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index c3007cb..dfd8060 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -130,9 +130,12 @@ static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask)
extern u64 dma_get_required_mask(struct device *dev);

#ifndef arch_setup_dma_ops
-static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base,
+static inline int arch_setup_dma_ops(struct device *dev, u64 dma_base,
u64 size, struct iommu_ops *iommu,
- bool coherent) { }
+ bool coherent)
+{
+ return 0;
+}
#endif

#ifndef arch_teardown_dma_ops
--
Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project

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