xref: /freebsd/sys/compat/linuxkpi/common/include/linux/efi.h (revision ebacd8013fe5f7fdf9f6a5b286f6680dd2891036)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2021 Vladimir Kondratyev <wulf@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #ifndef _LINUXKPI_LINUX_EFI_H_
29 #define	_LINUXKPI_LINUX_EFI_H_
30 
31 #include <sys/param.h>
32 #include <sys/queue.h>
33 #include <sys/linker.h>
34 #include <sys/systm.h>
35 
36 #include <machine/md_var.h>
37 #include <machine/metadata.h>
38 
39 #define	EFI_BOOT		0
40 
41 static inline bool
42 __efi_enabled(int feature)
43 {
44 #if defined(MODINFOMD_EFI_MAP) && !defined(__amd64__)
45 	caddr_t kmdp;
46 #endif
47 	bool enabled = false;
48 
49 	switch (feature) {
50 	case EFI_BOOT:
51 #ifdef __amd64__
52 		/* Use cached value on amd64 */
53 		enabled = efi_boot;
54 #elif defined(MODINFOMD_EFI_MAP)
55 		kmdp = preload_search_by_type("elf kernel");
56 		if (kmdp == NULL)
57 			kmdp = preload_search_by_type("elf64 kernel");
58 		enabled = preload_search_info(kmdp,
59 		    MODINFO_METADATA | MODINFOMD_EFI_MAP) != NULL;
60 #endif
61 		break;
62 	default:
63 		break;
64 	}
65 
66 	return (enabled);
67 }
68 
69 #define	efi_enabled(x)	({					\
70 	_Static_assert((x) == EFI_BOOT, "unsupported feature");	\
71 	__efi_enabled(x);					\
72 })
73 
74 #endif	/* _LINUXKPI_LINUX_EFI_H_ */
75