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Commit 684502ee authored by Mark Rutland's avatar Mark Rutland Committed by Olav Haugan
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arm64: smp: prepare for smp_processor_id() rework 



Subsequent patches will make smp_processor_id() use a percpu variable.
This will make smp_processor_id() dependent on the percpu offset, and
thus we cannot use smp_processor_id() to figure out what to initialise
the offset to.

Prepare for this by initialising the percpu offset based on
current::cpu, which will work regardless of how smp_processor_id() is
implemented. Also, make this relationship obvious by placing this code
together at the start of secondary_start_kernel().

Change-Id: I6869433127c3f9117d0a8009fc3418924cdedfc2
Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Tested-by: default avatarLaura Abbott <labbott@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Git-commit: 580efaa7ccfb8c0790dce4396434f0e5ac8d86ee
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


[ohaugan@codeaurora.org: Fix merge conflict]
Signed-off-by: default avatarOlav Haugan <ohaugan@codeaurora.org>
parent d72a7b50

arch/arm64/kernel/smp.c

+4 −3
Original line number Diff line number Diff line
@@ -209,7 +209,10 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) 
asmlinkage void secondary_start_kernel(void)

{

	struct mm_struct *mm = &init_mm;

	unsigned int cpu = smp_processor_id();

	unsigned int cpu;



	cpu = task_cpu(current);

	set_my_cpu_offset(per_cpu_offset(cpu));



	/*

	 * All kernel threads share the same mm context; grab a
@@ -218,8 +221,6 @@ asmlinkage void secondary_start_kernel(void) 
	atomic_inc(&mm->mm_count);

	current->active_mm = mm;



	set_my_cpu_offset(per_cpu_offset(smp_processor_id()));



	pr_debug("CPU%u: Booted secondary processor\n", cpu);



	/*