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The C and C++ Include Header Files

cat -n /usr/include/xen/gntalloc.h

     1	/******************************************************************************
     2	 * gntalloc.h
     3	 *
     4	 * Interface to /dev/xen/gntalloc.
     5	 *
     6	 * Author: Daniel De Graaf <dgdegra@tycho.nsa.gov>
     7	 *
     8	 * This file is in the public domain.
     9	 */
    10	
    11	#ifndef __LINUX_PUBLIC_GNTALLOC_H__
    12	#define __LINUX_PUBLIC_GNTALLOC_H__
    13	
    14	#include <linux/types.h>
    15	
    16	/*
    17	 * Allocates a new page and creates a new grant reference.
    18	 */
    19	#define IOCTL_GNTALLOC_ALLOC_GREF \
    20	_IOC(_IOC_NONE, 'G', 5, sizeof(struct ioctl_gntalloc_alloc_gref))
    21	struct ioctl_gntalloc_alloc_gref {
    22		/* IN parameters */
    23		/* The ID of the domain to be given access to the grants. */
    24		__u16 domid;
    25		/* Flags for this mapping */
    26		__u16 flags;
    27		/* Number of pages to map */
    28		__u32 count;
    29		/* OUT parameters */
    30		/* The offset to be used on a subsequent call to mmap(). */
    31		__u64 index;
    32		/* The grant references of the newly created grant, one per page */
    33		/* Variable size, depending on count */
    34		union {
    35			__u32 gref_ids[1];
    36			__DECLARE_FLEX_ARRAY(__u32, gref_ids_flex);
    37		};
    38	};
    39	
    40	#define GNTALLOC_FLAG_WRITABLE 1
    41	
    42	/*
    43	 * Deallocates the grant reference, allowing the associated page to be freed if
    44	 * no other domains are using it.
    45	 */
    46	#define IOCTL_GNTALLOC_DEALLOC_GREF \
    47	_IOC(_IOC_NONE, 'G', 6, sizeof(struct ioctl_gntalloc_dealloc_gref))
    48	struct ioctl_gntalloc_dealloc_gref {
    49		/* IN parameters */
    50		/* The offset returned in the map operation */
    51		__u64 index;
    52		/* Number of references to unmap */
    53		__u32 count;
    54	};
    55	
    56	/*
    57	 * Sets up an unmap notification within the page, so that the other side can do
    58	 * cleanup if this side crashes. Required to implement cross-domain robust
    59	 * mutexes or close notification on communication channels.
    60	 *
    61	 * Each mapped page only supports one notification; multiple calls referring to
    62	 * the same page overwrite the previous notification. You must clear the
    63	 * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it
    64	 * to occur.
    65	 */
    66	#define IOCTL_GNTALLOC_SET_UNMAP_NOTIFY \
    67	_IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntalloc_unmap_notify))
    68	struct ioctl_gntalloc_unmap_notify {
    69		/* IN parameters */
    70		/* Offset in the file descriptor for a byte within the page (same as
    71		 * used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to
    72		 * be cleared. Otherwise, it can be any byte in the page whose
    73		 * notification we are adjusting.
    74		 */
    75		__u64 index;
    76		/* Action(s) to take on unmap */
    77		__u32 action;
    78		/* Event channel to notify */
    79		__u32 event_channel_port;
    80	};
    81	
    82	/* Clear (set to zero) the byte specified by index */
    83	#define UNMAP_NOTIFY_CLEAR_BYTE 0x1
    84	/* Send an interrupt on the indicated event channel */
    85	#define UNMAP_NOTIFY_SEND_EVENT 0x2
    86	
    87	#endif /* __LINUX_PUBLIC_GNTALLOC_H__ */