linux_dsm_epyc7002/arch/x86/include/asm/xen/page-coherent.h
Stefano Stabellini a0f2dee0cd xen: add a dma_addr_t dev_addr argument to xen_dma_map_page
dev_addr is the machine address of the page.

The new parameter can be used by the ARM and ARM64 implementations of
xen_dma_map_page to find out if the page is a local page (pfn == mfn) or
a foreign page (pfn != mfn).

dev_addr could be retrieved again from the physical address, using
pfn_to_mfn, but it requires accessing an rbtree. Since we already have
the dev_addr in our hands at the call site there is no need to get the
mfn twice.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-12-04 12:41:51 +00:00

39 lines
1.3 KiB
C

#ifndef _ASM_X86_XEN_PAGE_COHERENT_H
#define _ASM_X86_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)
{
void *vstart = (void*)__get_free_pages(flags, get_order(size));
*dma_handle = virt_to_phys(vstart);
return vstart;
}
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)
{
free_pages((unsigned long) cpu_addr, get_order(size));
}
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, 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_X86_XEN_PAGE_COHERENT_H */