x86/boot/64: Use a common function for starting CPUs (a9468df5) · Commits · 戴 / test

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>

arch/x86/kernel/head_64.S

+11 −11

Original line number	Diff line number	Diff line
		@@ -270,8 +270,12 @@ ENTRY(secondary_startup_64)
		/* rsi is pointer to real mode structure with interesting info.
		pass it to C */
		movq %rsi, %rdi
		jmp start_cpu
		ENDPROC(secondary_startup_64)

		/* Finally jump to run C code and to be on real kernel address
		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
		jmp start_cpu
		ENDPROC(start_cpu0)
		#endif

Admin message