eisa.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * EISA specific code
 4 */
 5#include <linux/cc_platform.h>
 6#include <linux/ioport.h>
 7#include <linux/eisa.h>
 8#include <linux/io.h>
 9
10#include <xen/xen.h>
11
12static __init int eisa_bus_probe(void)
13{
14	u32 *p;
15
16	if ((xen_pv_domain() && !xen_initial_domain()) || cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
17		return 0;
18
19	p = memremap(0x0FFFD9, 4, MEMREMAP_WB);
20	if (p && *p == 'E' + ('I' << 8) + ('S' << 16) + ('A' << 24))
21		EISA_bus = 1;
22	memunmap(p);
23	return 0;
24}
25subsys_initcall(eisa_bus_probe);