linux_dsm_epyc7002/arch/arm64/include/asm/xen/page-coherent.h
Stefano Stabellini 02ab71cdae xen/arm64: do not call the swiotlb functions twice
On arm64 the dma_map_ops implementation is based on the swiotlb.
swiotlb-xen, used by default in dom0 on Xen, is also based on the
swiotlb.

Avoid calling into the default arm64 dma_map_ops functions from
xen_dma_map_page, xen_dma_unmap_page, xen_dma_sync_single_for_cpu, and
xen_dma_sync_single_for_device otherwise we end up calling into the
swiotlb twice.

When arm64 gets a non-swiotlb based implementation of dma_map_ops, we'll
probably have to reintroduce dma_map_ops calls in page-coherent.h.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: catalin.marinas@arm.com
CC: Will.Deacon@arm.com
CC: Ian.Campbell@citrix.com
2013-12-11 16:21:00 +00:00

44 lines
1.2 KiB
C

#ifndef _ASM_ARM64_XEN_PAGE_COHERENT_H
#define _ASM_ARM64_XEN_PAGE_COHERENT_H
#include <asm/page.h>
#include <linux/dma-attrs.h>
#include <linux/dma-mapping.h>
static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags,
struct dma_attrs *attrs)
{
return __generic_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,
struct dma_attrs *attrs)
{
__generic_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
}
static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
}
static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
size_t size, enum dma_data_direction dir,
struct dma_attrs *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)
{
}
static inline void xen_dma_sync_single_for_device(struct device *hwdev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
}
#endif /* _ASM_ARM64_XEN_PAGE_COHERENT_H */