git: 89bb7f9bda32 - main - LinuxKPI: Implement efi_enabled(EFI_BOOT)

The branch main has been updated by wulf:

URL: https://cgit.FreeBSD.org/src/commit/?id=89bb7f9bda32d9d54c03a488ed136efdd366cdeb

commit 89bb7f9bda32d9d54c03a488ed136efdd366cdeb
Author:     Vladimir Kondratyev <wulf@FreeBSD.org>
AuthorDate: 2021-12-06 10:14:36 +0000
Commit:     Vladimir Kondratyev <wulf@FreeBSD.org>
CommitDate: 2022-01-10 19:49:38 +0000

    LinuxKPI: Implement efi_enabled(EFI_BOOT)
    
    efi_enabled(EFI_BOOT) returns true if machine was booted from EFI
    Used by drm-kmod and some unported drm drivers like hyperv
    
    MFC after:      1 week
    Reviewed by:    hselasky, manu
    Differential Revision:  https://reviews.freebsd.org/D33300
---
 sys/compat/linuxkpi/common/include/linux/efi.h | 73 ++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/sys/compat/linuxkpi/common/include/linux/efi.h b/sys/compat/linuxkpi/common/include/linux/efi.h
new file mode 100644
index 000000000000..b7b0e681b6f2
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/linux/efi.h
@@ -0,0 +1,73 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 Vladimir Kondratyev <wulf@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _LINUX_EFI_H_
+#define	_LINUX_EFI_H_
+
+#include <sys/param.h>
+#include <sys/linker.h>
+#include <sys/systm.h>
+
+#include <machine/md_var.h>
+#include <machine/metadata.h>
+
+#define	EFI_BOOT		0
+
+static inline bool
+__efi_enabled(int feature)
+{
+#if defined(MODINFOMD_EFI_MAP) && !defined(__amd64__)
+	caddr_t kmdp;
+#endif
+	bool enabled = false;
+
+	switch (feature) {
+	case EFI_BOOT:
+#ifdef __amd64__
+		/* Use cached value on amd64 */
+		enabled = efi_boot;
+#elif defined(MODINFOMD_EFI_MAP)
+		kmdp = preload_search_by_type("elf kernel");
+		if (kmdp == NULL)
+			kmdp = preload_search_by_type("elf64 kernel");
+		enabled = preload_search_info(kmdp,
+		    MODINFO_METADATA | MODINFOMD_EFI_MAP) != NULL;
+#endif
+		break;
+	default:
+		break;
+	}
+
+	return (enabled);
+}
+
+#define	efi_enabled(x)	({					\
+	_Static_assert((x) == EFI_BOOT, "unsupported feature");	\
+	__efi_enabled(x);					\
+})
+
+#endif	/* _LINUX_EFI_H_ */