Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d0de0f68 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar
Browse files

x86/boot: Defer setup_real_mode() to early_initcall time 



There's no need to run setup_real_mode() as early as we run it.
Defer it to the same early_initcall that sets up the page
permissions for the real mode code.

This should be a code size reduction.  More importantly, it give us
a longer window in which we can allocate the real mode trampoline.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Matt Fleming <mfleming@suse.de>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/fd62f0da4f79357695e9bf3e365623736b05f119.1470821230.git.luto@kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 18bc7bd5

arch/x86/include/asm/realmode.h

+0 −1
Original line number Diff line number Diff line
@@ -59,6 +59,5 @@ extern unsigned char secondary_startup_64[]; 
#endif



void reserve_real_mode(void);

void setup_real_mode(void);



#endif /* _ARCH_X86_REALMODE_H */

arch/x86/kernel/setup.c

+0 −2
Original line number Diff line number Diff line
@@ -1141,8 +1141,6 @@ void __init setup_arch(char **cmdline_p) 
		/* A CPU has %cr4 if and only if it has CPUID. */

		mmu_cr4_features = __read_cr4();



	setup_real_mode();



	memblock_set_current_limit(get_max_mapped());



	/*

arch/x86/realmode/init.c

+12 −3
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ void __init reserve_real_mode(void) 
	       base, (unsigned long long)mem, size);

}



void __init setup_real_mode(void)

static void __init setup_real_mode(void)

{

	u16 real_mode_seg;

	const u32 *rel;
@@ -101,7 +101,7 @@ void __init setup_real_mode(void) 
 * need to mark it executable at do_pre_smp_initcalls() at least,

 * thus run it as a early_initcall().

 */

static int __init set_real_mode_permissions(void)

static void __init set_real_mode_permissions(void)

{

	unsigned char *base = (unsigned char *) real_mode_header;

	size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
@@ -120,7 +120,16 @@ static int __init set_real_mode_permissions(void) 
	set_memory_nx((unsigned long) base, size >> PAGE_SHIFT);

	set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT);

	set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT);

}



static int __init init_real_mode(void)

{

	if (!real_mode_header)

		panic("Real mode trampoline was not allocated");



	setup_real_mode();

	set_real_mode_permissions();



	return 0;

}

early_initcall(set_real_mode_permissions);
 
early_initcall(init_real_mode);