powerpc: Put FP/VSX and VR state into structures

This creates new 'thread_fp_state' and 'thread_vr_state' structures
to store FP/VSX state (including FPSCR) and Altivec/VSX state
(including VSCR), and uses them in the thread_struct.  In the
thread_fp_state, the FPRs and VSRs are represented as u64 rather
than double, since we rarely perform floating-point computations
on the values, and this will enable the structures to be used
in KVM code as well.  Similarly FPSCR is now a u64 rather than
a structure of two 32-bit values.

This takes the offsets out of the macros such as SAVE_32FPRS,
REST_32FPRS, etc.  This enables the same macros to be used for normal
and transactional state, enabling us to delete the transactional
versions of the macros.   This also removes the unused do_load_up_fpu
and do_load_up_altivec, which were in fact buggy since they didn't
create large enough stack frames to account for the fact that
load_up_fpu and load_up_altivec are not designed to be called from C
and assume that their caller's stack frame is an interrupt frame.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 15 insertions, 35 deletions

diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
index 9e20999aaef2..a48df870b696 100644
--- a/arch/powerpc/kernel/vector.S
+++ b/arch/powerpc/kernel/vector.S
@@ -8,29 +8,6 @@
 #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
@@ -46,10 +23,11 @@ _GLOBAL(do_load_up_transact_altivec)
 	li	r4,1
 	stw	r4,THREAD_USED_VR(r3)
 
-	li	r10,THREAD_TRANSACT_VSCR
+	li	r10,THREAD_TRANSACT_VRSTATE+VRSTATE_VSCR
 	lvx	vr0,r10,r3
 	mtvscr	vr0
-	REST_32VRS_TRANSACT(0,r4,r3)
+	addi	r10,r3,THREAD_TRANSACT_VRSTATE
+	REST_32VRS(0,r4,r10)
 
 	/* Disable VEC again. */
 	MTMSRD(r6)
@@ -59,7 +37,6 @@ _GLOBAL(do_load_up_transact_altivec)
 #endif
 
 /*
- * load_up_altivec(unused, unused, tsk)
  * Disable VMX for the task which had it previously,
  * and save its vector registers in its thread_struct.
  * Enables the VMX for use in the kernel on return.
@@ -90,10 +67,11 @@ _GLOBAL(load_up_altivec)
 	/* Save VMX state to last_task_used_altivec's THREAD struct */
 	toreal(r4)
 	addi	r4,r4,THREAD
-	SAVE_32VRS(0,r5,r4)
+	addi	r7,r4,THREAD_VRSTATE
+	SAVE_32VRS(0,r5,r7)
 	mfvscr	vr0
-	li	r10,THREAD_VSCR
-	stvx	vr0,r10,r4
+	li	r10,VRSTATE_VSCR
+	stvx	vr0,r10,r7
 	/* Disable VMX for last_task_used_altivec */
 	PPC_LL	r5,PT_REGS(r4)
 	toreal(r5)
@@ -125,12 +103,13 @@ _GLOBAL(load_up_altivec)
 	oris	r12,r12,MSR_VEC@h
 	std	r12,_MSR(r1)
 #endif
+	addi	r7,r5,THREAD_VRSTATE
 	li	r4,1
-	li	r10,THREAD_VSCR
+	li	r10,VRSTATE_VSCR
 	stw	r4,THREAD_USED_VR(r5)
-	lvx	vr0,r10,r5
+	lvx	vr0,r10,r7
 	mtvscr	vr0
-	REST_32VRS(0,r4,r5)
+	REST_32VRS(0,r4,r7)
 #ifndef CONFIG_SMP
 	/* Update last_task_used_altivec to 'current' */
 	subi	r4,r5,THREAD		/* Back to 'current' */
@@ -165,12 +144,13 @@ _GLOBAL(giveup_altivec)
 	PPC_LCMPI	0,r3,0
 	beqlr				/* if no previous owner, done */
 	addi	r3,r3,THREAD		/* want THREAD of task */
+	addi	r7,r3,THREAD_VRSTATE
 	PPC_LL	r5,PT_REGS(r3)
 	PPC_LCMPI	0,r5,0
-	SAVE_32VRS(0,r4,r3)
+	SAVE_32VRS(0,r4,r7)
 	mfvscr	vr0
-	li	r4,THREAD_VSCR
-	stvx	vr0,r4,r3
+	li	r4,VRSTATE_VSCR
+	stvx	vr0,r4,r7
 	beq	1f
 	PPC_LL	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
 #ifdef CONFIG_VSX