Commit-ID: a9468df5ad48d06e5237fc2b56fb04c52f79c8c4 Gitweb: http://git.kernel.org/tip/a9468df5ad48d06e5237fc2b56fb04c52f79c8c4 Author: Josh Poimboeuf <jpoim...@redhat.com> AuthorDate: Wed, 21 Sep 2016 16:04:04 -0500 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 20 Oct 2016 09:15:23 +0200
x86/boot/64: Use a common function for starting CPUs There are two different pieces of code for starting a CPU: start_cpu0() and the end of secondary_startup_64(). They're identical except for the stack setup. Combine the common parts into a shared start_cpu() function. Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com> Cc: Andy Lutomirski <l...@kernel.org> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Nilay Vaish <nilayva...@gmail.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/1d692ffa62fcb3cc835a5b254e953f2d9bab3549.1474480779.git.jpoim...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/head_64.S | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index b4421cc..3631777 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -265,13 +265,17 @@ ENTRY(secondary_startup_64) movl $MSR_GS_BASE,%ecx movl initial_gs(%rip),%eax movl initial_gs+4(%rip),%edx - wrmsr + wrmsr /* rsi is pointer to real mode structure with interesting info. pass it to C */ movq %rsi, %rdi - - /* Finally jump to run C code and to be on real kernel address + jmp start_cpu +ENDPROC(secondary_startup_64) + +ENTRY(start_cpu) + /* + * Jump to run C code and to be on a real kernel address. * Since we are running on identity-mapped space we have to jump * to the full 64bit address, this is only possible as indirect * jump. In addition we need to ensure %cs is set so we make this @@ -300,7 +304,7 @@ ENTRY(secondary_startup_64) pushq $__KERNEL_CS # set correct cs pushq %rax # target address in negative space lretq -ENDPROC(secondary_startup_64) +ENDPROC(start_cpu) #include "verify_cpu.S" @@ -308,15 +312,11 @@ ENDPROC(secondary_startup_64) /* * Boot CPU0 entry point. It's called from play_dead(). Everything has been set * up already except stack. We just set up stack here. Then call - * start_secondary(). + * start_secondary() via start_cpu(). */ ENTRY(start_cpu0) - movq initial_stack(%rip),%rsp - movq initial_code(%rip),%rax - pushq $0 # fake return address to stop unwinder - pushq $__KERNEL_CS # set correct cs - pushq %rax # target address in negative space - lretq + movq initial_stack(%rip), %rsp + jmp start_cpu ENDPROC(start_cpu0) #endif
