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authorJosh Poimboeuf <jpoimboe@redhat.com>2016-09-21 16:04:04 -0500
committerIngo Molnar <mingo@kernel.org>2016-10-20 09:15:23 +0200
commita9468df5ad48d06e5237fc2b56fb04c52f79c8c4 (patch)
tree3ddc88fe4975680b0af45645cd13769e1bbf590f /arch/x86/kernel/head_64.S
parentb9b1a9c363ff7b17b2a35e20e28e86a449cfde1f (diff)
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 <jpoimboe@redhat.com> Cc: Andy 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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1d692ffa62fcb3cc835a5b254e953f2d9bab3549.1474480779.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/head_64.S')
-rw-r--r--arch/x86/kernel/head_64.S22
1 files changed, 11 insertions, 11 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index b4421cc191b0..363177790110 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