[PATCH 01/13] xen/arm: use dma-noncoherent.h calls for xen-swiotlb cache maintainance

Christoph Hellwig
2019-09-02T13:04:03Z

Copy the arm64 code that uses the dma-direct/swiotlb helpers for DMA
on-coherent devices.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/arm/include/asm/device.h | 3 -
arch/arm/include/asm/xen/page-coherent.h | 72 +++++++++---------------
arch/arm/mm/dma-mapping.c | 8 +--
drivers/xen/swiotlb-xen.c | 20 -------
4 files changed, 28 insertions(+), 75 deletions(-)

diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h
index f6955b55c544..c675bc0d5aa8 100644
--- a/arch/arm/include/asm/device.h
+++ b/arch/arm/include/asm/device.h
@@ -14,9 +14,6 @@ struct dev_archdata {
#endif
#ifdef CONFIG_ARM_DMA_USE_IOMMU
struct dma_iommu_mapping *mapping;
-#endif
-#ifdef CONFIG_XEN
- const struct dma_map_ops *dev_dma_ops;
#endif
unsigned int dma_coherent:1;
unsigned int dma_ops_setup:1;
diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h
index 2c403e7c782d..602ac02f154c 100644
--- a/arch/arm/include/asm/xen/page-coherent.h
+++ b/arch/arm/include/asm/xen/page-coherent.h
@@ -6,23 +6,37 @@
#include <asm/page.h>
#include <xen/arm/page-coherent.h>

-static inline const struct dma_map_ops *xen_get_dma_ops(struct device *dev)
-{
- if (dev && dev->archdata.dev_dma_ops)
- return dev->archdata.dev_dma_ops;
- return get_arch_dma_ops(NULL);
-}
-
static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs)
{
- return xen_get_dma_ops(hwdev)->alloc(hwdev, size, dma_handle, flags, attrs);
+ return dma_direct_alloc(hwdev, size, dma_handle, flags, attrs);
}

static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs)
{
- xen_get_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
+ dma_direct_free(hwdev, size, cpu_addr, dma_handle, attrs);
+}
+
+static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
+ dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+ unsigned long pfn = PFN_DOWN(handle);
+
+ if (pfn_valid(pfn))
+ dma_direct_sync_single_for_cpu(hwdev, handle, size, dir);
+ else
+ __xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
+}
+
+static inline void xen_dma_sync_single_for_device(struct device *hwdev,
+ dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+ unsigned long pfn = PFN_DOWN(handle);
+ if (pfn_valid(pfn))
+ dma_direct_sync_single_for_device(hwdev, handle, size, dir);
+ else
+ __xen_dma_sync_single_for_device(hwdev, handle, size, dir);
}

static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
@@ -36,17 +50,8 @@ static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
bool local = (page_pfn <= dev_pfn) &&
(dev_pfn - page_pfn < compound_pages);

- /*
- * Dom0 is mapped 1:1, while the Linux page can span across
- * multiple Xen pages, it's not possible for it to contain a
- * mix of local and foreign Xen pages. So if the first xen_pfn
- * == mfn the page is local otherwise it's a foreign page
- * grant-mapped in dom0. If the page is local we can safely
- * call the native dma_ops function, otherwise we call the xen
- * specific function.
- */
if (local)
- xen_get_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
+ dma_direct_map_page(hwdev, page, offset, size, dir, attrs);
else
__xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
}
@@ -63,33 +68,10 @@ static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
* safely call the native dma_ops function, otherwise we call the xen
* specific function.
*/
- if (pfn_valid(pfn)) {
- if (xen_get_dma_ops(hwdev)->unmap_page)
- xen_get_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
- } else
+ if (pfn_valid(pfn))
+ dma_direct_unmap_page(hwdev, handle, size, dir, attrs);
+ else
__xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
}

-static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
- dma_addr_t handle, size_t size, enum dma_data_direction dir)
-{
- unsigned long pfn = PFN_DOWN(handle);
- if (pfn_valid(pfn)) {
- if (xen_get_dma_ops(hwdev)->sync_single_for_cpu)
- xen_get_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
- } else
- __xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
-}
-
-static inline void xen_dma_sync_single_for_device(struct device *hwdev,
- dma_addr_t handle, size_t size, enum dma_data_direction dir)
-{
- unsigned long pfn = PFN_DOWN(handle);
- if (pfn_valid(pfn)) {
- if (xen_get_dma_ops(hwdev)->sync_single_for_device)
- xen_get_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
- } else
- __xen_dma_sync_single_for_device(hwdev, handle, size, dir);
-}
-
#endif /* _ASM_ARM_XEN_PAGE_COHERENT_H */
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index d42557ee69c2..738097396445 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1132,10 +1132,6 @@ static const struct dma_map_ops *arm_get_dma_map_ops(bool coherent)
* 32-bit DMA.
* Use the generic dma-direct / swiotlb ops code in that case, as that
* handles bounce buffering for us.
- *
- * Note: this checks CONFIG_ARM_LPAE instead of CONFIG_SWIOTLB as the
- * latter is also selected by the Xen code, but that code for now relies
- * on non-NULL dev_dma_ops. To be cleaned up later.
*/
if (IS_ENABLED(CONFIG_ARM_LPAE))
return NULL;
@@ -2363,10 +2359,8 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
set_dma_ops(dev, dma_ops);

#ifdef CONFIG_XEN
- if (xen_initial_domain()) {
- dev->archdata.dev_dma_ops = dev->dma_ops;
+ if (xen_initial_domain())
dev->dma_ops = xen_dma_ops;
- }
#endif
dev->archdata.dma_ops_setup = true;
}
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index ae1df496bf38..eee86cc7046b 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -557,11 +557,6 @@ xen_swiotlb_dma_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
-#ifdef CONFIG_ARM
- if (xen_get_dma_ops(dev)->mmap)
- return xen_get_dma_ops(dev)->mmap(dev, vma, cpu_addr,
- dma_addr, size, attrs);
-#endif
return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
}

@@ -574,21 +569,6 @@ xen_swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t handle, size_t size,
unsigned long attrs)
{
-#ifdef CONFIG_ARM
- if (xen_get_dma_ops(dev)->get_sgtable) {
-#if 0
- /*
- * This check verifies that the page belongs to the current domain and
- * is not one mapped from another domain.
- * This check is for debug only, and should not go to production build
- */
- unsigned long bfn = PHYS_PFN(dma_to_phys(dev, handle));
- BUG_ON (!page_is_ram(bfn));
-#endif
- return xen_get_dma_ops(dev)->get_sgtable(dev, sgt, cpu_addr,
- handle, size, attrs);
- }
-#endif
return dma_common_get_sgtable(dev, sgt, cpu_addr, handle, size, attrs);