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Commit f3d885cc authored by Anton Blanchard's avatar Anton Blanchard Committed by Michael Ellerman
Browse files

powerpc: Rearrange __switch_to() 



Most of __switch_to() is housekeeping, TLB batching, timekeeping etc.
Move these away from the more complex and critical context switching
code.

Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 579e633e

arch/powerpc/kernel/process.c

+26 −26
Original line number Diff line number Diff line
@@ -907,30 +907,6 @@ struct task_struct *__switch_to(struct task_struct *prev, 


	WARN_ON(!irqs_disabled());



	/*

	 * We need to save SPRs before treclaim/trecheckpoint as these will

	 * change a number of them.

	 */

	save_sprs(&prev->thread);



	__switch_to_tm(prev);



	/* Save FPU, Altivec, VSX and SPE state */

	giveup_all(prev);



#ifdef CONFIG_PPC_ADV_DEBUG_REGS

	switch_booke_debug_regs(&new->thread.debug);

#else

/*

 * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would

 * schedule DABR

 */

#ifndef CONFIG_HAVE_HW_BREAKPOINT

	if (unlikely(!hw_brk_match(this_cpu_ptr(&current_brk), &new->thread.hw_brk)))

		__set_breakpoint(&new->thread.hw_brk);

#endif /* CONFIG_HAVE_HW_BREAKPOINT */

#endif



#ifdef CONFIG_PPC64

	/*

	 * Collect processor utilization data per process
@@ -955,6 +931,30 @@ struct task_struct *__switch_to(struct task_struct *prev, 
	}

#endif /* CONFIG_PPC_BOOK3S_64 */



#ifdef CONFIG_PPC_ADV_DEBUG_REGS

	switch_booke_debug_regs(&new->thread.debug);

#else

/*

 * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would

 * schedule DABR

 */

#ifndef CONFIG_HAVE_HW_BREAKPOINT

	if (unlikely(!hw_brk_match(this_cpu_ptr(&current_brk), &new->thread.hw_brk)))

		__set_breakpoint(&new->thread.hw_brk);

#endif /* CONFIG_HAVE_HW_BREAKPOINT */

#endif



	/*

	 * We need to save SPRs before treclaim/trecheckpoint as these will

	 * change a number of them.

	 */

	save_sprs(&prev->thread);



	__switch_to_tm(prev);



	/* Save FPU, Altivec, VSX and SPE state */

	giveup_all(prev);



	/*

	 * We can't take a PMU exception inside _switch() since there is a

	 * window where the kernel stack SLB and the kernel stack are out
@@ -970,6 +970,8 @@ struct task_struct *__switch_to(struct task_struct *prev, 
	old_thread = &last->thread;

	new_thread = &current->thread;



	restore_sprs(old_thread, new_thread);



#ifdef CONFIG_PPC_BOOK3S_64

	if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {

		current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
@@ -978,8 +980,6 @@ struct task_struct *__switch_to(struct task_struct *prev, 
	}

#endif /* CONFIG_PPC_BOOK3S_64 */



	restore_sprs(old_thread, new_thread);



	return last;

}