powerpc: Prepare for splitting giveup_{fpu, altivec, vsx} in two
This prepares for the decoupling of saving {fpu,altivec,vsx} registers and
marking {fpu,altivec,vsx} as being unused by a thread.
Currently giveup_{fpu,altivec,vsx}() does both however optimisations to
task switching can be made if these two operations are decoupled.
save_all() will permit the saving of registers to thread structs and leave
threads MSR with bits enabled.
This patch introduces no functional change.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 11a81bd..52ed654 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -75,6 +75,14 @@
#define MSR_HV 0
#endif
+/*
+ * To be used in shared book E/book S, this avoids needing to worry about
+ * book S/book E in shared code
+ */
+#ifndef MSR_SPE
+#define MSR_SPE 0
+#endif
+
#define MSR_VEC __MASK(MSR_VEC_LG) /* Enable AltiVec */
#define MSR_VSX __MASK(MSR_VSX_LG) /* Enable VSX */
#define MSR_POW __MASK(MSR_POW_LG) /* Enable Power Management */
diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h
index 5b268b6..3690041 100644
--- a/arch/powerpc/include/asm/switch_to.h
+++ b/arch/powerpc/include/asm/switch_to.h
@@ -34,6 +34,7 @@
msr_check_and_clear(MSR_FP);
}
#else
+static inline void __giveup_fpu(struct task_struct *t) { }
static inline void flush_fp_to_thread(struct task_struct *t) { }
#endif
@@ -46,6 +47,8 @@
{
msr_check_and_clear(MSR_VEC);
}
+#else
+static inline void __giveup_altivec(struct task_struct *t) { }
#endif
#ifdef CONFIG_VSX
@@ -57,6 +60,8 @@
{
msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);
}
+#else
+static inline void __giveup_vsx(struct task_struct *t) { }
#endif
#ifdef CONFIG_SPE
@@ -68,6 +73,8 @@
{
msr_check_and_clear(MSR_SPE);
}
+#else
+static inline void __giveup_spe(struct task_struct *t) { }
#endif
static inline void clear_task_ebb(struct task_struct *t)