summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/vector.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/kernel/vector.S')
-rw-r--r--arch/powerpc/kernel/vector.S37
1 files changed, 8 insertions, 29 deletions
diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
index 1c2e7a343bf5..0c123f3406cd 100644
--- a/arch/powerpc/kernel/vector.S
+++ b/arch/powerpc/kernel/vector.S
@@ -6,31 +6,7 @@
#include <asm/thread_info.h>
#include <asm/page.h>
#include <asm/ptrace.h>
-
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-/* void do_load_up_transact_altivec(struct thread_struct *thread)
- *
- * This is similar to load_up_altivec but for the transactional version of the
- * vector regs. It doesn't mess with the task MSR or valid flags.
- * Furthermore, VEC laziness is not supported with TM currently.
- */
-_GLOBAL(do_load_up_transact_altivec)
- mfmsr r6
- oris r5,r6,MSR_VEC@h
- MTMSRD(r5)
- isync
-
- li r4,1
- stw r4,THREAD_USED_VR(r3)
-
- li r10,THREAD_TRANSACT_VRSTATE+VRSTATE_VSCR
- lvx v0,r10,r3
- mtvscr v0
- addi r10,r3,THREAD_TRANSACT_VRSTATE
- REST_32VRS(0,r4,r10)
-
- blr
-#endif
+#include <asm/export.h>
/*
* Load state from memory into VMX registers including VSCR.
@@ -42,6 +18,7 @@ _GLOBAL(load_vr_state)
mtvscr v0
REST_32VRS(0,r4,r3)
blr
+EXPORT_SYMBOL(load_vr_state)
/*
* Store VMX state into memory, including VSCR.
@@ -53,6 +30,7 @@ _GLOBAL(store_vr_state)
li r4, VRSTATE_VSCR
stvx v0, r4, r3
blr
+EXPORT_SYMBOL(store_vr_state)
/*
* Disable VMX for the task which had it previously,
@@ -70,10 +48,11 @@ _GLOBAL(load_up_altivec)
MTMSRD(r5) /* enable use of AltiVec now */
isync
- /* Hack: if we get an altivec unavailable trap with VRSAVE
- * set to all zeros, we assume this is a broken application
- * that fails to set it properly, and thus we switch it to
- * all 1's
+ /*
+ * While userspace in general ignores VRSAVE, glibc uses it as a boolean
+ * to optimise userspace context save/restore. Whenever we take an
+ * altivec unavailable exception we must set VRSAVE to something non
+ * zero. Set it to all 1s. See also the programming note in the ISA.
*/
mfspr r4,SPRN_VRSAVE
cmpwi 0,r4,0
OpenPOWER on IntegriCloud