Linux-libre 4.8.2-gnupck-4.8.2-gnu

1 files changed, 36 insertions, 13 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 0b9389342..9ee2623e0 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -58,6 +58,7 @@
 #include <asm/code-patching.h>
 #include <asm/exec.h>
 #include <asm/livepatch.h>
+#include <asm/cpu_has_feature.h>
 
 #include <linux/kprobes.h>
 #include <linux/kdebug.h>
@@ -139,12 +140,16 @@ EXPORT_SYMBOL(__msr_check_and_clear);
 #ifdef CONFIG_PPC_FPU
 void __giveup_fpu(struct task_struct *tsk)
 {
+	unsigned long msr;
+
 	save_fpu(tsk);
-	tsk->thread.regs->msr &= ~MSR_FP;
+	msr = tsk->thread.regs->msr;
+	msr &= ~MSR_FP;
 #ifdef CONFIG_VSX
 	if (cpu_has_feature(CPU_FTR_VSX))
-		tsk->thread.regs->msr &= ~MSR_VSX;
+		msr &= ~MSR_VSX;
 #endif
+	tsk->thread.regs->msr = msr;
 }
 
 void giveup_fpu(struct task_struct *tsk)
@@ -219,12 +224,16 @@ static int restore_fp(struct task_struct *tsk) { return 0; }
 
 static void __giveup_altivec(struct task_struct *tsk)
 {
+	unsigned long msr;
+
 	save_altivec(tsk);
-	tsk->thread.regs->msr &= ~MSR_VEC;
+	msr = tsk->thread.regs->msr;
+	msr &= ~MSR_VEC;
 #ifdef CONFIG_VSX
 	if (cpu_has_feature(CPU_FTR_VSX))
-		tsk->thread.regs->msr &= ~MSR_VSX;
+		msr &= ~MSR_VSX;
 #endif
+	tsk->thread.regs->msr = msr;
 }
 
 void giveup_altivec(struct task_struct *tsk)
@@ -794,7 +803,7 @@ static void tm_reclaim_thread(struct thread_struct *thr,
 	 * this state.
 	 * We do this using the current MSR, rather tracking it in
 	 * some specific thread_struct bit, as it has the additional
-	 * benifit of checking for a potential TM bad thing exception.
+	 * benefit of checking for a potential TM bad thing exception.
 	 */
 	if (!MSR_TM_SUSPENDED(mfmsr()))
 		return;
@@ -1009,6 +1018,14 @@ static inline void save_sprs(struct thread_struct *t)
 		 */
 		t->tar = mfspr(SPRN_TAR);
 	}
+
+	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+		/* Conditionally save Load Monitor registers, if enabled */
+		if (t->fscr & FSCR_LM) {
+			t->lmrr = mfspr(SPRN_LMRR);
+			t->lmser = mfspr(SPRN_LMSER);
+		}
+	}
 #endif
 }
 
@@ -1023,18 +1040,11 @@ static inline void restore_sprs(struct thread_struct *old_thread,
 #ifdef CONFIG_PPC_BOOK3S_64
 	if (cpu_has_feature(CPU_FTR_DSCR)) {
 		u64 dscr = get_paca()->dscr_default;
-		u64 fscr = old_thread->fscr & ~FSCR_DSCR;
-
-		if (new_thread->dscr_inherit) {
+		if (new_thread->dscr_inherit)
 			dscr = new_thread->dscr;
-			fscr |= FSCR_DSCR;
-		}
 
 		if (old_thread->dscr != dscr)
 			mtspr(SPRN_DSCR, dscr);
-
-		if (old_thread->fscr != fscr)
-			mtspr(SPRN_FSCR, fscr);
 	}
 
 	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
@@ -1045,9 +1055,22 @@ static inline void restore_sprs(struct thread_struct *old_thread,
 		if (old_thread->ebbrr != new_thread->ebbrr)
 			mtspr(SPRN_EBBRR, new_thread->ebbrr);
 
+		if (old_thread->fscr != new_thread->fscr)
+			mtspr(SPRN_FSCR, new_thread->fscr);
+
 		if (old_thread->tar != new_thread->tar)
 			mtspr(SPRN_TAR, new_thread->tar);
 	}
+
+	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+		/* Conditionally restore Load Monitor registers, if enabled */
+		if (new_thread->fscr & FSCR_LM) {
+			if (old_thread->lmrr != new_thread->lmrr)
+				mtspr(SPRN_LMRR, new_thread->lmrr);
+			if (old_thread->lmser != new_thread->lmser)
+				mtspr(SPRN_LMSER, new_thread->lmser);
+		}
+	}
 #endif
 }