1/* SPDX-License-Identifier: GPL-2.0 */
2#include <xen/arm/page-coherent.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

  1#ifndef _ASM_ARM_XEN_PAGE_COHERENT_H
  2#define _ASM_ARM_XEN_PAGE_COHERENT_H
  3
  4#include <asm/page.h>
  5#include <linux/dma-attrs.h>
  6#include <linux/dma-mapping.h>
  7
  8void __xen_dma_map_page(struct device *hwdev, struct page *page,
  9	     dma_addr_t dev_addr, unsigned long offset, size_t size,
 10	     enum dma_data_direction dir, struct dma_attrs *attrs);
 11void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
 12		size_t size, enum dma_data_direction dir,
 13		struct dma_attrs *attrs);
 14void __xen_dma_sync_single_for_cpu(struct device *hwdev,
 15		dma_addr_t handle, size_t size, enum dma_data_direction dir);
 16
 17void __xen_dma_sync_single_for_device(struct device *hwdev,
 18		dma_addr_t handle, size_t size, enum dma_data_direction dir);
 19
 20static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
 21		dma_addr_t *dma_handle, gfp_t flags,
 22		struct dma_attrs *attrs)
 23{
 24	return __generic_dma_ops(hwdev)->alloc(hwdev, size, dma_handle, flags, attrs);
 25}
 26
 27static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
 28		void *cpu_addr, dma_addr_t dma_handle,
 29		struct dma_attrs *attrs)
 30{
 31	__generic_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
 32}
 33
 34static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
 35	     dma_addr_t dev_addr, unsigned long offset, size_t size,
 36	     enum dma_data_direction dir, struct dma_attrs *attrs)
 37{
 38	unsigned long page_pfn = page_to_xen_pfn(page);
 39	unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
 40	unsigned long compound_pages =
 41		(1<<compound_order(page)) * XEN_PFN_PER_PAGE;
 42	bool local = (page_pfn <= dev_pfn) &&
 43		(dev_pfn - page_pfn < compound_pages);
 44
 45	/*
 46	 * Dom0 is mapped 1:1, while the Linux page can span across
 47	 * multiple Xen pages, it's not possible for it to contain a
 48	 * mix of local and foreign Xen pages. So if the first xen_pfn
 49	 * == mfn the page is local otherwise it's a foreign page
 50	 * grant-mapped in dom0. If the page is local we can safely
 51	 * call the native dma_ops function, otherwise we call the xen
 52	 * specific function.
 53	 */
 54	if (local)
 55		__generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
 56	else
 57		__xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
 58}
 59
 60static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
 61		size_t size, enum dma_data_direction dir,
 62		struct dma_attrs *attrs)
 63{
 64	unsigned long pfn = PFN_DOWN(handle);
 65	/*
 66	 * Dom0 is mapped 1:1, while the Linux page can be spanned accross
 67	 * multiple Xen page, it's not possible to have a mix of local and
 68	 * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
 69	 * foreign mfn will always return false. If the page is local we can
 70	 * safely call the native dma_ops function, otherwise we call the xen
 71	 * specific function.
 72	 */
 73	if (pfn_valid(pfn)) {
 74		if (__generic_dma_ops(hwdev)->unmap_page)
 75			__generic_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
 76	} else
 77		__xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
 78}
 79
 80static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
 81		dma_addr_t handle, size_t size, enum dma_data_direction dir)
 82{
 83	unsigned long pfn = PFN_DOWN(handle);
 84	if (pfn_valid(pfn)) {
 85		if (__generic_dma_ops(hwdev)->sync_single_for_cpu)
 86			__generic_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
 87	} else
 88		__xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
 89}
 90
 91static inline void xen_dma_sync_single_for_device(struct device *hwdev,
 92		dma_addr_t handle, size_t size, enum dma_data_direction dir)
 93{
 94	unsigned long pfn = PFN_DOWN(handle);
 95	if (pfn_valid(pfn)) {
 96		if (__generic_dma_ops(hwdev)->sync_single_for_device)
 97			__generic_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
 98	} else
 99		__xen_dma_sync_single_for_device(hwdev, handle, size, dir);
100}
101
102#endif /* _ASM_ARM_XEN_PAGE_COHERENT_H */