Subject: [PATCH 1/3] powerpc: Complete FSCR context switch

From: Jack Miller <[email-masked]>
Date: Mon, 11 Apr 2016 13:57:43 -0500

Previously we just saved the FSCR, but only restored it in some
settings, and never copied it thread to thread. This patch always
restores the FSCR and formalizes new threads inheriting its setting so
that later we can manipulate FSCR bits in start_thread.

Signed-off-by: Jack Miller <[email-masked]>
---
 arch/powerpc/kernel/process.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index b8500b4..0c7e797 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1043,6 +1043,10 @@ static inline void restore_sprs(struct thread_struct *old_thread,
 
 		if (old_thread->tar != new_thread->tar)
 			mtspr(SPRN_TAR, new_thread->tar);
+
+		if (old_thread->fscr != new_thread->fscr)
+			mtspr(SPRN_FSCR, new_thread->fscr);
+
 	}
 #endif
 }
@@ -1478,6 +1482,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	}
 	if (cpu_has_feature(CPU_FTR_HAS_PPR))
 		p->thread.ppr = INIT_PPR;
+
+	if (cpu_has_feature(CPU_FTR_ARCH_207S))
+		p->thread.fscr = mfspr(SPRN_FSCR);
 #endif
 	kregs->nip = ppc_function_entry(f);
 	return 0;
-- 
2.8.0