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Commit b86fd2bd authored by Anton Blanchard's avatar Anton Blanchard Committed by Michael Ellerman
Browse files

powerpc: Simplify TM restore checks 



Instead of having multiple giveup_*_maybe_transactional() functions,
separate out the TM check into a new function called
check_if_tm_restore_required().

This will make it easier to optimise the giveup_*() functions in a
subsequent patch.

Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent af1bbc3d

arch/powerpc/kernel/process.c

+19 −34
Original line number Diff line number Diff line
@@ -68,7 +68,7 @@ 
extern unsigned long _get_SP(void);



#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

void giveup_fpu_maybe_transactional(struct task_struct *tsk)

static void check_if_tm_restore_required(struct task_struct *tsk)

{

	/*

	 * If we are saving the current thread's registers, and the
@@ -82,31 +82,9 @@ void giveup_fpu_maybe_transactional(struct task_struct *tsk) 
		tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;

		set_thread_flag(TIF_RESTORE_TM);

	}



	giveup_fpu(tsk);

}



void giveup_altivec_maybe_transactional(struct task_struct *tsk)

{

	/*

	 * If we are saving the current thread's registers, and the

	 * thread is in a transactional state, set the TIF_RESTORE_TM

	 * bit so that we know to restore the registers before

	 * returning to userspace.

	 */

	if (tsk == current && tsk->thread.regs &&

	    MSR_TM_ACTIVE(tsk->thread.regs->msr) &&

	    !test_thread_flag(TIF_RESTORE_TM)) {

		tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;

		set_thread_flag(TIF_RESTORE_TM);

	}



	giveup_altivec(tsk);

}



#else

#define giveup_fpu_maybe_transactional(tsk)	giveup_fpu(tsk)

#define giveup_altivec_maybe_transactional(tsk)	giveup_altivec(tsk)

static inline void check_if_tm_restore_required(struct task_struct *tsk) { }

#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */



#ifdef CONFIG_PPC_FPU
@@ -135,7 +113,8 @@ void flush_fp_to_thread(struct task_struct *tsk) 
			 * to still have its FP state in the CPU registers.

			 */

			BUG_ON(tsk != current);

			giveup_fpu_maybe_transactional(tsk);

			check_if_tm_restore_required(tsk);

			giveup_fpu(tsk);

		}

		preempt_enable();

	}
@@ -147,11 +126,13 @@ void enable_kernel_fp(void) 
{

	WARN_ON(preemptible());



	if (current->thread.regs && (current->thread.regs->msr & MSR_FP))

		giveup_fpu_maybe_transactional(current);

	else

	if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {

		check_if_tm_restore_required(current);

		giveup_fpu(current);

	} else {

		giveup_fpu(NULL);	/* just enables FP for kernel */

	}

}

EXPORT_SYMBOL(enable_kernel_fp);



#ifdef CONFIG_ALTIVEC
@@ -159,11 +140,13 @@ void enable_kernel_altivec(void) 
{

	WARN_ON(preemptible());



	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))

		giveup_altivec_maybe_transactional(current);

	else

	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {

		check_if_tm_restore_required(current);

		giveup_altivec(current);

	} else {

		giveup_altivec_notask();

	}

}

EXPORT_SYMBOL(enable_kernel_altivec);



/*
@@ -176,7 +159,8 @@ void flush_altivec_to_thread(struct task_struct *tsk) 
		preempt_disable();

		if (tsk->thread.regs->msr & MSR_VEC) {

			BUG_ON(tsk != current);

			giveup_altivec_maybe_transactional(tsk);

			check_if_tm_restore_required(tsk);

			giveup_altivec(tsk);

		}

		preempt_enable();

	}
@@ -198,8 +182,9 @@ EXPORT_SYMBOL(enable_kernel_vsx); 


void giveup_vsx(struct task_struct *tsk)

{

	giveup_fpu_maybe_transactional(tsk);

	giveup_altivec_maybe_transactional(tsk);

	check_if_tm_restore_required(tsk);

	giveup_fpu(tsk);

	giveup_altivec(tsk);

	__giveup_vsx(tsk);

}

EXPORT_SYMBOL(giveup_vsx);