powerpc: Add FP/VSX and VMX register load functions for transactional memory

This adds functions to restore the state of the FP/VSX registers from
what's stored in the thread_struct.  Two version for FP/VSX are required
since one restores them from transactional/checkpoint side of the
thread_struct and the other from the speculated side.

Similar functions are added for VMX registers.

Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 105 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index adb155195394..caeaabf11a2f 100644
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -62,6 +62,60 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX);					\
         __REST_32FPVSRS_TRANSACT(n,__REG_##c,__REG_##base)
 #define SAVE_32FPVSRS(n,c,base) __SAVE_32FPVSRS(n,__REG_##c,__REG_##base)
 
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+/*
+ * Wrapper to call load_up_fpu from C.
+ * void do_load_up_fpu(struct pt_regs *regs);
+ */
+_GLOBAL(do_load_up_fpu)
+        mflr    r0
+        std     r0, 16(r1)
+        stdu    r1, -112(r1)
+
+        subi    r6, r3, STACK_FRAME_OVERHEAD
+        /* load_up_fpu expects r12=MSR, r13=PACA, and returns
+         * with r12 = new MSR.
+         */
+        ld      r12,_MSR(r6)
+        GET_PACA(r13)
+
+        bl      load_up_fpu
+        std     r12,_MSR(r6)
+
+        ld      r0, 112+16(r1)
+        addi    r1, r1, 112
+        mtlr    r0
+        blr
+
+
+/* void do_load_up_transact_fpu(struct thread_struct *thread)
+ *
+ * This is similar to load_up_fpu but for the transactional version of the FP
+ * register set.  It doesn't mess with the task MSR or valid flags.
+ * Furthermore, we don't do lazy FP with TM currently.
+ */
+_GLOBAL(do_load_up_transact_fpu)
+        mfmsr   r6
+        ori     r5,r6,MSR_FP
+#ifdef CONFIG_VSX
+BEGIN_FTR_SECTION
+        oris    r5,r5,MSR_VSX@h
+END_FTR_SECTION_IFSET(CPU_FTR_VSX)
+#endif
+        SYNC
+        MTMSRD(r5)
+
+        lfd     fr0,THREAD_TRANSACT_FPSCR(r3)
+        MTFSF_L(fr0)
+        REST_32FPVSRS_TRANSACT(0, R4, R3)
+
+        /* FP/VSX off again */
+        MTMSRD(r6)
+        SYNC
+
+        blr
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+
 /*
  * This task wants to use the FPU now.
  * On UP, disable FP for the task which had the FPU previously,
diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
index e830289d2e48..9e20999aaef2 100644
--- a/arch/powerpc/kernel/vector.S
+++ b/arch/powerpc/kernel/vector.S
@@ -7,6 +7,57 @@
 #include <asm/page.h>
 #include <asm/ptrace.h>
 
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+/*
+ * Wrapper to call load_up_altivec from C.
+ * void do_load_up_altivec(struct pt_regs *regs);
+ */
+_GLOBAL(do_load_up_altivec)
+        mflr    r0
+        std     r0, 16(r1)
+        stdu    r1, -112(r1)
+
+        subi    r6, r3, STACK_FRAME_OVERHEAD
+        /* load_up_altivec expects r12=MSR, r13=PACA, and returns
+         * with r12 = new MSR.
+         */
+        ld      r12,_MSR(r6)
+        GET_PACA(r13)
+        bl      load_up_altivec
+        std     r12,_MSR(r6)
+
+        ld      r0, 112+16(r1)
+        addi    r1, r1, 112
+        mtlr    r0
+        blr
+
+/* 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_VSCR
+        lvx     vr0,r10,r3
+        mtvscr  vr0
+        REST_32VRS_TRANSACT(0,r4,r3)
+
+        /* Disable VEC again. */
+        MTMSRD(r6)
+        isync
+
+        blr
+#endif
+
 /*
  * load_up_altivec(unused, unused, tsk)
  * Disable VMX for the task which had it previously,