[PATCH 01/11] xen/arm: use dma-noncoherent.h calls for xen-swiotlb cache maintainance

Christoph Hellwig
2019-08-26T12:21:57Z

Reuse the arm64 code that uses the dma-direct/swiotlb helpers for DMA
non-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 | 93 ----------------------
arch/arm/mm/dma-mapping.c | 8 +-
arch/arm64/include/asm/xen/page-coherent.h | 75 -----------------
drivers/xen/swiotlb-xen.c | 49 +-----------
include/xen/arm/page-coherent.h | 80 +++++++++++++++++++
6 files changed, 83 insertions(+), 225 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..27e984977402 100644
--- a/arch/arm/include/asm/xen/page-coherent.h
+++ b/arch/arm/include/asm/xen/page-coherent.h
@@ -1,95 +1,2 @@
/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_ARM_XEN_PAGE_COHERENT_H
-#define _ASM_ARM_XEN_PAGE_COHERENT_H
-
-#include <linux/dma-mapping.h>
-#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);
-}
-
-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);
-}
-
-static inline 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)
-{
- unsigned long page_pfn = page_to_xen_pfn(page);
- unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
- unsigned long compound_pages =
- (1<<compound_order(page)) * XEN_PFN_PER_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);
- else
- __xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
-}
-
-static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
- size_t size, enum dma_data_direction dir, unsigned long attrs)
-{
- unsigned long pfn = PFN_DOWN(handle);
- /*
- * Dom0 is mapped 1:1, while the Linux page can be spanned accross
- * multiple Xen page, it's not possible to have a mix of local and
- * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
- * foreign mfn will always return false. If the page is local we can
- * 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
- __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/arch/arm64/include/asm/xen/page-coherent.h b/arch/arm64/include/asm/xen/page-coherent.h
index d88e56b90b93..27e984977402 100644
--- a/arch/arm64/include/asm/xen/page-coherent.h
+++ b/arch/arm64/include/asm/xen/page-coherent.h
@@ -1,77 +1,2 @@
/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_ARM64_XEN_PAGE_COHERENT_H
-#define _ASM_ARM64_XEN_PAGE_COHERENT_H
-
-#include <linux/dma-mapping.h>
-#include <asm/page.h>
#include <xen/arm/page-coherent.h>
-
-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 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)
-{
- 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,
- dma_addr_t dev_addr, unsigned long offset, size_t size,
- enum dma_data_direction dir, unsigned long attrs)
-{
- unsigned long page_pfn = page_to_xen_pfn(page);
- unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
- unsigned long compound_pages =
- (1<<compound_order(page)) * XEN_PFN_PER_PAGE;
- bool local = (page_pfn <= dev_pfn) &&
- (dev_pfn - page_pfn < compound_pages);
-
- if (local)
- dma_direct_map_page(hwdev, page, offset, size, dir, attrs);
- else
- __xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
-}
-
-static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
- size_t size, enum dma_data_direction dir, unsigned long attrs)
-{
- unsigned long pfn = PFN_DOWN(handle);
- /*
- * Dom0 is mapped 1:1, while the Linux page can be spanned accross
- * multiple Xen page, it's not possible to have a mix of local and
- * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
- * foreign mfn will always return false. If the page is local we can
- * safely call the native dma_ops function, otherwise we call the xen
- * specific function.
- */
- if (pfn_valid(pfn))
- dma_direct_unmap_page(hwdev, handle, size, dir, attrs);
- else
- __xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
-}
-
-#endif /* _ASM_ARM64_XEN_PAGE_COHERENT_H */
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index ae1df496bf38..b8808677ae1d 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -547,51 +547,6 @@ xen_swiotlb_dma_supported(struct device *hwdev, u64 mask)
return xen_virt_to_bus(xen_io_tlb_end - 1) <= mask;
}

-/*
- * Create userspace mapping for the DMA-coherent memory.
- * This function should be called with the pages from the current domain only,
- * passing pages mapped from other domains would lead to memory corruption.
- */
-static int
-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);
-}
-
-/*
- * This function should be called with the pages from the current domain only,
- * passing pages mapped from other domains would lead to memory corruption.
- */
-static int
-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);
-}
-
const struct dma_map_ops xen_swiotlb_dma_ops = {
.alloc = xen_swiotlb_alloc_coherent,
.free = xen_swiotlb_free_coherent,
@@ -604,6 +559,6 @@ const struct dma_map_ops xen_swiotlb_dma_ops = {
.map_page = xen_swiotlb_map_page,
.unmap_page = xen_swiotlb_unmap_page,
.dma_supported = xen_swiotlb_dma_supported,
- .mmap = xen_swiotlb_dma_mmap,
- .get_sgtable = xen_swiotlb_get_sgtable,
+ .mmap = dma_common_mmap,
+ .get_sgtable = dma_common_get_sgtable,
};
diff --git a/include/xen/arm/page-coherent.h b/include/xen/arm/page-coherent.h
index 2ca9164a79bf..a840d6949a87 100644
--- a/include/xen/arm/page-coherent.h
+++ b/include/xen/arm/page-coherent.h
@@ -2,6 +2,9 @@
#ifndef _XEN_ARM_PAGE_COHERENT_H
#define _XEN_ARM_PAGE_COHERENT_H

+#include <linux/dma-mapping.h>
+#include <asm/page.h>
+
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);
@@ -13,4 +16,81 @@ void __xen_dma_sync_single_for_cpu(struct device *hwdev,
void __xen_dma_sync_single_for_device(struct device *hwdev,
dma_addr_t handle, size_t size, enum dma_data_direction dir);

+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 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)
+{
+ 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,
+ dma_addr_t dev_addr, unsigned long offset, size_t size,
+ enum dma_data_direction dir, unsigned long attrs)
+{
+ unsigned long page_pfn = page_to_xen_pfn(page);
+ unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
+ unsigned long compound_pages =
+ (1<<compound_order(page)) * XEN_PFN_PER_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)
+ dma_direct_map_page(hwdev, page, offset, size, dir, attrs);
+ else
+ __xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
+}
+
+static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
+ size_t size, enum dma_data_direction dir, unsigned long attrs)
+{
+ unsigned long pfn = PFN_DOWN(handle);
+ /*
+ * Dom0 is mapped 1:1, while the Linux page can be spanned accross
+ * multiple Xen page, it's not possible to have a mix of local and
+ * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
+ * foreign mfn will always return false. If the page is local we can
+ * safely call the native dma_ops function, otherwise we call the xen
+ * specific function.
+ */
+ if (pfn_valid(pfn))
+ dma_direct_unmap_page(hwdev, handle, size, dir, attrs);
+ else
+ __xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
+}
+
#endif /* _XEN_ARM_PAGE_COHERENT_H */
--
2.20.1