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	Add UAPI and IOCTLs for dma-buf grant device driver extension: the extension allows userspace processes and kernel modules to use Xen backed dma-buf implementation. With this extension grant references to the pages of an imported dma-buf can be exported for other domain use and grant references coming from a foreign domain can be converted into a local dma-buf for local export. Implement basic initialization and stubs for Xen DMA buffers' support. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
		
			
				
	
	
		
			94 lines
		
	
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			94 lines
		
	
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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 * Common functionality of grant device.
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 *
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 * Copyright (c) 2006-2007, D G Murray.
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 *           (c) 2009 Gerd Hoffmann <kraxel@redhat.com>
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 *           (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
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 */
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#ifndef _GNTDEV_COMMON_H
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#define _GNTDEV_COMMON_H
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/mmu_notifier.h>
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#include <linux/types.h>
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struct gntdev_dmabuf_priv;
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struct gntdev_priv {
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	/* Maps with visible offsets in the file descriptor. */
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	struct list_head maps;
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	/*
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	 * Maps that are not visible; will be freed on munmap.
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	 * Only populated if populate_freeable_maps == 1
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	 */
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	struct list_head freeable_maps;
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	/* lock protects maps and freeable_maps. */
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	struct mutex lock;
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	struct mm_struct *mm;
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	struct mmu_notifier mn;
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#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
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	/* Device for which DMA memory is allocated. */
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	struct device *dma_dev;
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#endif
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#ifdef CONFIG_XEN_GNTDEV_DMABUF
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	struct gntdev_dmabuf_priv *dmabuf_priv;
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#endif
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};
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struct gntdev_unmap_notify {
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	int flags;
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	/* Address relative to the start of the gntdev_grant_map. */
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	int addr;
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	int event;
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};
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struct gntdev_grant_map {
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	struct list_head next;
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	struct vm_area_struct *vma;
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	int index;
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	int count;
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	int flags;
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	refcount_t users;
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	struct gntdev_unmap_notify notify;
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	struct ioctl_gntdev_grant_ref *grants;
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	struct gnttab_map_grant_ref   *map_ops;
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	struct gnttab_unmap_grant_ref *unmap_ops;
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	struct gnttab_map_grant_ref   *kmap_ops;
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	struct gnttab_unmap_grant_ref *kunmap_ops;
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	struct page **pages;
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	unsigned long pages_vm_start;
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#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
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	/*
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	 * If dmabuf_vaddr is not NULL then this mapping is backed by DMA
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	 * capable memory.
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	 */
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	struct device *dma_dev;
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	/* Flags used to create this DMA buffer: GNTDEV_DMA_FLAG_XXX. */
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	int dma_flags;
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	void *dma_vaddr;
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	dma_addr_t dma_bus_addr;
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	/* Needed to avoid allocation in gnttab_dma_free_pages(). */
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	xen_pfn_t *frames;
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#endif
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};
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struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
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					  int dma_flags);
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void gntdev_add_map(struct gntdev_priv *priv, struct gntdev_grant_map *add);
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void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map);
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bool gntdev_account_mapped_pages(int count);
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int gntdev_map_grant_pages(struct gntdev_grant_map *map);
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#endif
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