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#ifndef _IPXE_XENGRANT_H
#define _IPXE_XENGRANT_H
/** @file
*
* Xen grant tables
*
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdint.h>
#include <ipxe/io.h>
#include <ipxe/xen.h>
#include <xen/grant_table.h>
/**
* Query grant table size
*
* @v xen Xen hypervisor
* @v size Table size
* @ret xenrc Xen status code
*/
static inline __attribute__ (( always_inline )) int
xengrant_query_size ( struct xen_hypervisor *xen,
struct gnttab_query_size *size ) {
return xen_hypercall_3 ( xen, __HYPERVISOR_grant_table_op,
GNTTABOP_query_size,
virt_to_phys ( size ), 1 );
}
/**
* Set grant table version
*
* @v xen Xen hypervisor
* @v version Version
* @ret xenrc Xen status code
*/
static inline __attribute__ (( always_inline )) int
xengrant_set_version ( struct xen_hypervisor *xen,
struct gnttab_set_version *version ) {
return xen_hypercall_3 ( xen, __HYPERVISOR_grant_table_op,
GNTTABOP_set_version,
virt_to_phys ( version ), 1 );
}
/**
* Invalidate access to a page
*
* @v xen Xen hypervisor
* @v ref Grant reference
*/
static inline __attribute__ (( always_inline )) void
xengrant_invalidate ( struct xen_hypervisor *xen, grant_ref_t ref ) {
union grant_entry_v2 *entry = &xen->grant.table[ref];
/* Sanity check */
assert ( ( readw ( &entry->hdr.flags ) &
( GTF_reading | GTF_writing ) ) == 0 );
/* This should apparently be done using a cmpxchg instruction.
* We omit this: partly in the interests of simplicity, but
* mainly since our control flow generally does not permit
* failure paths to themselves fail.
*/
writew ( 0, &entry->hdr.flags );
}
/**
* Permit access to a page
*
* @v xen Xen hypervisor
* @v ref Grant reference
* @v domid Domain ID
* @v subflags Additional flags
* @v page Page start
*/
static inline __attribute__ (( always_inline )) void
xengrant_permit_access ( struct xen_hypervisor *xen, grant_ref_t ref,
domid_t domid, unsigned int subflags, void *page ) {
union grant_entry_v2 *entry = &xen->grant.table[ref];
unsigned long frame = ( virt_to_phys ( page ) / PAGE_SIZE );
writew ( domid, &entry->full_page.hdr.domid );
if ( sizeof ( physaddr_t ) == sizeof ( uint64_t ) ) {
writeq ( frame, &entry->full_page.frame );
} else {
writel ( frame, &entry->full_page.frame );
}
wmb();
writew ( ( GTF_permit_access | subflags ), &entry->full_page.hdr.flags);
wmb();
}
extern int xengrant_alloc ( struct xen_hypervisor *xen, grant_ref_t *refs,
unsigned int count );
extern void xengrant_free ( struct xen_hypervisor *xen, grant_ref_t *refs,
unsigned int count );
#endif /* _IPXE_XENGRANT_H */
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