xref: /OK3568_Linux_fs/kernel/drivers/xen/features.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /******************************************************************************
3*4882a593Smuzhiyun  * features.c
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * Xen feature flags.
6*4882a593Smuzhiyun  *
7*4882a593Smuzhiyun  * Copyright (c) 2006, Ian Campbell, XenSource Inc.
8*4882a593Smuzhiyun  */
9*4882a593Smuzhiyun #include <linux/types.h>
10*4882a593Smuzhiyun #include <linux/cache.h>
11*4882a593Smuzhiyun #include <linux/export.h>
12*4882a593Smuzhiyun 
13*4882a593Smuzhiyun #include <asm/xen/hypercall.h>
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun #include <xen/interface/xen.h>
16*4882a593Smuzhiyun #include <xen/interface/version.h>
17*4882a593Smuzhiyun #include <xen/features.h>
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun u8 xen_features[XENFEAT_NR_SUBMAPS * 32] __read_mostly;
20*4882a593Smuzhiyun EXPORT_SYMBOL_GPL(xen_features);
21*4882a593Smuzhiyun 
xen_setup_features(void)22*4882a593Smuzhiyun void xen_setup_features(void)
23*4882a593Smuzhiyun {
24*4882a593Smuzhiyun 	struct xen_feature_info fi;
25*4882a593Smuzhiyun 	int i, j;
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun 	for (i = 0; i < XENFEAT_NR_SUBMAPS; i++) {
28*4882a593Smuzhiyun 		fi.submap_idx = i;
29*4882a593Smuzhiyun 		if (HYPERVISOR_xen_version(XENVER_get_features, &fi) < 0)
30*4882a593Smuzhiyun 			break;
31*4882a593Smuzhiyun 		for (j = 0; j < 32; j++)
32*4882a593Smuzhiyun 			xen_features[i * 32 + j] = !!(fi.submap & 1U << j);
33*4882a593Smuzhiyun 	}
34*4882a593Smuzhiyun }
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