1 /******************************************************************************
2  * features.c
3  *
4  * Xen feature flags.
5  *
6  * Copyright (c) 2006, Ian Campbell, XenSource Inc.
7  */
8 #include <linux/types.h>
9 #include <linux/cache.h>
10 #include <linux/export.h>
11 
12 #include <asm/xen/hypercall.h>
13 
14 #include <xen/interface/xen.h>
15 #include <xen/interface/version.h>
16 #include <xen/features.h>
17 
18 u8 xen_features[XENFEAT_NR_SUBMAPS * 32] __read_mostly;
19 EXPORT_SYMBOL_GPL(xen_features);
20 
xen_setup_features(void)21 void xen_setup_features(void)
22 {
23 	struct xen_feature_info fi;
24 	int i, j;
25 
26 	for (i = 0; i < XENFEAT_NR_SUBMAPS; i++) {
27 		fi.submap_idx = i;
28 		if (HYPERVISOR_xen_version(XENVER_get_features, &fi) < 0)
29 			break;
30 		for (j = 0; j < 32; j++)
31 			xen_features[i * 32 + j] = !!(fi.submap & 1<<j);
32 	}
33 }
34