linux-brain/arch/x86/include/asm/xen/page-coherent.h
Christoph Hellwig b4dca15129 swiotlb-xen: simplify cache maintainance
Now that we know we always have the dma-noncoherent.h helpers available
if we are on an architecture with support for non-coherent devices,
we can just call them directly, and remove the calls to the dma-direct
routines, including the fact that we call the dma_direct_map_page
routines but ignore the value returned from it.  Instead we now have
Xen wrappers for the arch_sync_dma_for_{device,cpu} helpers that call
the special Xen versions of those routines for foreign pages.

Note that the new helpers get the physical address passed in addition
to the dma address to avoid another translation for the local cache
maintainance.  The pfn_valid checks remain on the dma address as in
the old code, even if that looks a little funny.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2019-09-11 12:43:27 +02:00

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C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_XEN_PAGE_COHERENT_H
#define _ASM_X86_XEN_PAGE_COHERENT_H
#include <asm/page.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,
unsigned long 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,
unsigned long attrs)
{
free_pages((unsigned long) cpu_addr, get_order(size));
}
#endif /* _ASM_X86_XEN_PAGE_COHERENT_H */