diff mbox

[12/19] powerpc: Create msr_check_and_{set,clear}()

Message ID 1446079451-8774-13-git-send-email-anton@samba.org (mailing list archive)
State Accepted
Headers show

Commit Message

Anton Blanchard Oct. 29, 2015, 12:44 a.m. UTC 
Create helper functions to set and clear MSR bits after first
checking if they are already set. Grouping them will make it
easy to avoid the MSR writes in a subsequent optimisation.

Signed-off-by: Anton Blanchard <anton@samba.org>
---
 arch/powerpc/kernel/process.c | 107 ++++++++++++++++++++----------------------
 1 file changed, 52 insertions(+), 55 deletions(-)

Comments

kernel test robot Oct. 29, 2015, 7:25 a.m. UTC | #1 
Hi Anton,

[auto build test ERROR on powerpc/next -- if it's inappropriate base, please suggest rules for selecting the more suitable base]

url:    https://github.com/0day-ci/linux/commits/Anton-Blanchard/Context-switch-improvements/20151029-092229
config: powerpc-virtex_defconfig (attached as .config)
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=powerpc 

Note: the linux-review/Anton-Blanchard/Context-switch-improvements/20151029-092229 HEAD 13bdf12302e872951c7835777c51a7e04f784fb0 builds fine.
      It only hurts bisectibility.

All errors (new ones prefixed by >>):

>> arch/powerpc/kernel/process.c:106:13: error: 'msr_check_and_clear' defined but not used [-Werror=unused-function]
    static void msr_check_and_clear(unsigned long bits)
                ^
   cc1: all warnings being treated as errors

vim +/msr_check_and_clear +106 arch/powerpc/kernel/process.c

   100	#endif
   101	
   102		if (oldmsr != newmsr)
   103			mtmsr_isync(newmsr);
   104	}
   105	
 > 106	static void msr_check_and_clear(unsigned long bits)
   107	{
   108		unsigned long oldmsr = mfmsr();
   109		unsigned long newmsr;

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
diff mbox

Patch

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 0cb6276..5cdd35c 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -87,23 +87,46 @@  static void check_if_tm_restore_required(struct task_struct *tsk)
 static inline void check_if_tm_restore_required(struct task_struct *tsk) { }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
-#ifdef CONFIG_PPC_FPU
-void giveup_fpu(struct task_struct *tsk)
+static void msr_check_and_set(unsigned long bits)
 {
-	u64 oldmsr = mfmsr();
-	u64 newmsr;
+	unsigned long oldmsr = mfmsr();
+	unsigned long newmsr;
 
-	check_if_tm_restore_required(tsk);
+	newmsr = oldmsr | bits;
 
-	newmsr = oldmsr | MSR_FP;
 #ifdef CONFIG_VSX
-	if (cpu_has_feature(CPU_FTR_VSX))
+	if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
 		newmsr |= MSR_VSX;
 #endif
+
 	if (oldmsr != newmsr)
 		mtmsr_isync(newmsr);
+}
+
+static void msr_check_and_clear(unsigned long bits)
+{
+	unsigned long oldmsr = mfmsr();
+	unsigned long newmsr;
+
+	newmsr = oldmsr & ~bits;
+
+#ifdef CONFIG_VSX
+	if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
+		newmsr &= ~MSR_VSX;
+#endif
 
+	if (oldmsr != newmsr)
+		mtmsr_isync(newmsr);
+}
+
+#ifdef CONFIG_PPC_FPU
+void giveup_fpu(struct task_struct *tsk)
+{
+	check_if_tm_restore_required(tsk);
+
+	msr_check_and_set(MSR_FP);
 	__giveup_fpu(tsk);
+	msr_check_and_clear(MSR_FP);
 }
 EXPORT_SYMBOL(giveup_fpu);
 
@@ -144,30 +167,21 @@  void enable_kernel_fp(void)
 {
 	WARN_ON(preemptible());
 
-	if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {
-		giveup_fpu(current);
-	} else {
-		u64 oldmsr = mfmsr();
+	msr_check_and_set(MSR_FP);
 
-		if (!(oldmsr & MSR_FP))
-			mtmsr_isync(oldmsr | MSR_FP);
-	}
+	if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
+		__giveup_fpu(current);
 }
 EXPORT_SYMBOL(enable_kernel_fp);
 
 #ifdef CONFIG_ALTIVEC
 void giveup_altivec(struct task_struct *tsk)
 {
-	u64 oldmsr = mfmsr();
-	u64 newmsr;
-
 	check_if_tm_restore_required(tsk);
 
-	newmsr = oldmsr | MSR_VEC;
-	if (oldmsr != newmsr)
-		mtmsr_isync(newmsr);
-
+	msr_check_and_set(MSR_VEC);
 	__giveup_altivec(tsk);
+	msr_check_and_clear(MSR_VEC);
 }
 EXPORT_SYMBOL(giveup_altivec);
 
@@ -175,14 +189,10 @@  void enable_kernel_altivec(void)
 {
 	WARN_ON(preemptible());
 
-	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {
-		giveup_altivec(current);
-	} else {
-		u64 oldmsr = mfmsr();
+	msr_check_and_set(MSR_VEC);
 
-		if (!(oldmsr & MSR_VEC))
-			mtmsr_isync(oldmsr | MSR_VEC);
-	}
+	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
+		__giveup_altivec(current);
 }
 EXPORT_SYMBOL(enable_kernel_altivec);
 
@@ -207,20 +217,15 @@  EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
 #ifdef CONFIG_VSX
 void giveup_vsx(struct task_struct *tsk)
 {
-	u64 oldmsr = mfmsr();
-	u64 newmsr;
-
 	check_if_tm_restore_required(tsk);
 
-	newmsr = oldmsr | (MSR_FP|MSR_VEC|MSR_VSX);
-	if (oldmsr != newmsr)
-		mtmsr_isync(newmsr);
-
+	msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
 	if (tsk->thread.regs->msr & MSR_FP)
 		__giveup_fpu(tsk);
 	if (tsk->thread.regs->msr & MSR_VEC)
 		__giveup_altivec(tsk);
 	__giveup_vsx(tsk);
+	msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);
 }
 EXPORT_SYMBOL(giveup_vsx);
 
@@ -228,13 +233,14 @@  void enable_kernel_vsx(void)
 {
 	WARN_ON(preemptible());
 
-	if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) {
-		giveup_vsx(current);
-	} else {
-		u64 oldmsr = mfmsr();
+	msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
 
-		if (!(oldmsr & MSR_VSX))
-			mtmsr_isync(oldmsr | MSR_VSX);
+	if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) {
+		if (current->thread.regs->msr & MSR_FP)
+			__giveup_fpu(current);
+		if (current->thread.regs->msr & MSR_VEC)
+			__giveup_altivec(current);
+		__giveup_vsx(current);
 	}
 }
 EXPORT_SYMBOL(enable_kernel_vsx);
@@ -256,16 +262,11 @@  EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
 #ifdef CONFIG_SPE
 void giveup_spe(struct task_struct *tsk)
 {
-	u64 oldmsr = mfmsr();
-	u64 newmsr;
-
 	check_if_tm_restore_required(tsk);
 
-	newmsr = oldmsr | MSR_SPE;
-	if (oldmsr != newmsr)
-		mtmsr_isync(newmsr);
-
+	msr_check_and_set(MSR_SPE);
 	__giveup_spe(tsk);
+	msr_check_and_clear(MSR_SPE);
 }
 EXPORT_SYMBOL(giveup_spe);
 
@@ -273,14 +274,10 @@  void enable_kernel_spe(void)
 {
 	WARN_ON(preemptible());
 
-	if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) {
-		giveup_spe(current);
-	} else {
-		u64 oldmsr = mfmsr();
+	msr_check_and_set(MSR_SPE);
 
-		if (!(oldmsr & MSR_SPE))
-			mtmsr_isync(oldmsr | MSR_SPE);
-	}
+	if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
+		__giveup_spe(current);
 }
 EXPORT_SYMBOL(enable_kernel_spe);