[PATCH 1/2] xen/arm,arm64: fix xen_dma_ops after 815dd18 "Consolidate get_dma_ops..."

From: Stefano Stabellini
Date: Thu Apr 13 2017 - 17:04:35 EST


The following commit:

commit 815dd18788fe0d41899f51b91d0560279cf16b0d
Author: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Date: Fri Jan 20 13:04:04 2017 -0800

treewide: Consolidate get_dma_ops() implementations

rearranges get_dma_ops in a way that xen_dma_ops are not returned when
running on Xen anymore, dev->dma_ops is returned instead (see
arch/arm/include/asm/dma-mapping.h:get_arch_dma_ops and
include/linux/dma-mapping.h:get_dma_ops).

Fix the problem by storing dev->dma_ops in dev_archdata, and setting
dev->dma_ops to xen_dma_ops. This way, xen_dma_ops is returned naturally
by get_dma_ops. The Xen code can retrieve the original dev->dma_ops from
dev_archdata when needed. It also allows us to remove __generic_dma_ops
from common headers.

Signed-off-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Tested-by: Julien Grall <julien.grall@xxxxxxx>
Suggested-by: Catalin Marinas <catalin.marinas@xxxxxxx>
CC: linux@xxxxxxxxxxxxxxx
CC: catalin.marinas@xxxxxxx
CC: will.deacon@xxxxxxx
CC: boris.ostrovsky@xxxxxxxxxx
CC: jgross@xxxxxxxx
CC: Julien Grall <julien.grall@xxxxxxx>
---
arch/arm/include/asm/device.h | 3 +++
arch/arm/include/asm/dma-mapping.h | 12 +-----------
arch/arm/mm/dma-mapping.c | 7 +++++++
arch/arm64/include/asm/device.h | 3 +++
arch/arm64/include/asm/dma-mapping.h | 13 +------------
arch/arm64/mm/dma-mapping.c | 7 +++++++
include/xen/arm/page-coherent.h | 8 ++++++++
7 files changed, 30 insertions(+), 23 deletions(-)

diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h
index 220ba20..36ec9c8 100644
--- a/arch/arm/include/asm/device.h
+++ b/arch/arm/include/asm/device.h
@@ -16,6 +16,9 @@ struct dev_archdata {
#ifdef CONFIG_ARM_DMA_USE_IOMMU
struct dma_iommu_mapping *mapping;
#endif
+#ifdef CONFIG_XEN
+ const struct dma_map_ops *dev_dma_ops;
+#endif
bool dma_coherent;
};

diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 7166569..680d3f3 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -16,19 +16,9 @@
extern const struct dma_map_ops arm_dma_ops;
extern const struct dma_map_ops arm_coherent_dma_ops;

-static inline const struct dma_map_ops *__generic_dma_ops(struct device *dev)
-{
- if (dev && dev->dma_ops)
- return dev->dma_ops;
- return &arm_dma_ops;
-}
-
static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
{
- if (xen_initial_domain())
- return xen_dma_ops;
- else
- return __generic_dma_ops(NULL);
+ return &arm_dma_ops;
}

#define HAVE_ARCH_DMA_SUPPORTED 1
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 63eabb0..a614459 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -2396,6 +2396,13 @@ 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);
+
+#ifdef CONFIG_XEN
+ if (xen_initial_domain()) {
+ dev->archdata.dev_dma_ops = dev->dma_ops;
+ dev->dma_ops = xen_dma_ops;
+ }
+#endif
}

void arch_teardown_dma_ops(struct device *dev)
diff --git a/arch/arm64/include/asm/device.h b/arch/arm64/include/asm/device.h
index 73d5bab..5a5fa47 100644
--- a/arch/arm64/include/asm/device.h
+++ b/arch/arm64/include/asm/device.h
@@ -20,6 +20,9 @@ struct dev_archdata {
#ifdef CONFIG_IOMMU_API
void *iommu; /* private IOMMU data */
#endif
+#ifdef CONFIG_XEN
+ const struct dma_map_ops *dev_dma_ops;
+#endif
bool dma_coherent;
};

diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h
index 505756c..5392dbe 100644
--- a/arch/arm64/include/asm/dma-mapping.h
+++ b/arch/arm64/include/asm/dma-mapping.h
@@ -27,11 +27,8 @@
#define DMA_ERROR_CODE (~(dma_addr_t)0)
extern const struct dma_map_ops dummy_dma_ops;

-static inline const struct dma_map_ops *__generic_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
{
- if (dev && dev->dma_ops)
- return dev->dma_ops;
-
/*
* We expect no ISA devices, and all other DMA masters are expected to
* have someone call arch_setup_dma_ops at device creation time.
@@ -39,14 +36,6 @@ static inline const struct dma_map_ops *__generic_dma_ops(struct device *dev)
return &dummy_dma_ops;
}

-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
-{
- if (xen_initial_domain())
- return xen_dma_ops;
- else
- return __generic_dma_ops(NULL);
-}
-
void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
const 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 81cdb2e..7f8b37e 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -977,4 +977,11 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,

dev->archdata.dma_coherent = coherent;
__iommu_setup_dma_ops(dev, dma_base, size, iommu);
+
+#ifdef CONFIG_XEN
+ if (xen_initial_domain()) {
+ dev->archdata.dev_dma_ops = dev->dma_ops;
+ dev->dma_ops = xen_dma_ops;
+ }
+#endif
}
diff --git a/include/xen/arm/page-coherent.h b/include/xen/arm/page-coherent.h
index 95ce6ac..b0a2bfc 100644
--- a/include/xen/arm/page-coherent.h
+++ b/include/xen/arm/page-coherent.h
@@ -2,8 +2,16 @@
#define _ASM_ARM_XEN_PAGE_COHERENT_H

#include <asm/page.h>
+#include <asm/dma-mapping.h>
#include <linux/dma-mapping.h>

+static inline const struct dma_map_ops *__generic_dma_ops(struct device *dev)
+{
+ if (dev && dev->archdata.dev_dma_ops)
+ return dev->archdata.dev_dma_ops;
+ return get_arch_dma_ops(NULL);
+}
+
void __xen_dma_map_page(struct device *hwdev, struct page *page,
dma_addr_t dev_addr, unsigned long offset, size_t size,
enum dma_data_direction dir, unsigned long attrs);
--
1.9.1