From d0de0f685db7faf2ae4597a39a59996dd84e18c7 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Wed, 10 Aug 2016 02:29:15 -0700 Subject: [PATCH] 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: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Mario Limonciello Cc: Matt Fleming Cc: Matthew Garrett Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/fd62f0da4f79357695e9bf3e365623736b05f119.1470821230.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/include/asm/realmode.h | 1 - arch/x86/kernel/setup.c | 2 -- arch/x86/realmode/init.c | 15 ++++++++++++--- 3 files changed, 12 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h index 9c6b890d5e7a..8d6777724ba4 100644 --- a/arch/x86/include/asm/realmode.h +++ b/arch/x86/include/asm/realmode.h @@ -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 */ diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 95c8c9c7dd6d..0fa60f5f5a16 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -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()); /* diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c index c5bdc4e473e7..747b71e8f547 100644 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -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); -- 2.20.1