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 12 static __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 } 25 subsys_initcall(eisa_bus_probe); 26