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, 13 insertions, 46 deletions

diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index caeaabf11a2f..34b96e6d2f0d 100644
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -35,15 +35,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX);					\
 2:	REST_32VSRS(n,c,base);						\
 3:
 
-#define __REST_32FPVSRS_TRANSACT(n,c,base)				\
-BEGIN_FTR_SECTION							\
-	b	2f;							\
-END_FTR_SECTION_IFSET(CPU_FTR_VSX);					\
-	REST_32FPRS_TRANSACT(n,base);					\
-	b	3f;							\
-2:	REST_32VSRS_TRANSACT(n,c,base);					\
-3:
-
 #define __SAVE_32FPVSRS(n,c,base)					\
 BEGIN_FTR_SECTION							\
 	b	2f;							\
@@ -54,40 +45,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX);					\
 3:
 #else
 #define __REST_32FPVSRS(n,b,base)	REST_32FPRS(n, base)
-#define __REST_32FPVSRS_TRANSACT(n,b,base)	REST_32FPRS(n, base)
 #define __SAVE_32FPVSRS(n,b,base)	SAVE_32FPRS(n, base)
 #endif
 #define REST_32FPVSRS(n,c,base) __REST_32FPVSRS(n,__REG_##c,__REG_##base)
-#define REST_32FPVSRS_TRANSACT(n,c,base) \
-	__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
@@ -105,9 +68,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 	SYNC
 	MTMSRD(r5)
 
-	lfd	fr0,THREAD_TRANSACT_FPSCR(r3)
+	addi	r7,r3,THREAD_TRANSACT_FPSTATE
+	lfd	fr0,FPSTATE_FPSCR(r7)
 	MTFSF_L(fr0)
-	REST_32FPVSRS_TRANSACT(0, R4, R3)
+	REST_32FPVSRS(0, R4, R7)
 
 	/* FP/VSX off again */
 	MTMSRD(r6)
@@ -147,9 +111,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 	beq	1f
 	toreal(r4)
 	addi	r4,r4,THREAD		/* want last_task_used_math->thread */
-	SAVE_32FPVSRS(0, R5, R4)
+	addi	r8,r4,THREAD_FPSTATE
+	SAVE_32FPVSRS(0, R5, R8)
 	mffs	fr0
-	stfd	fr0,THREAD_FPSCR(r4)
+	stfd	fr0,FPSTATE_FPSCR(r8)
 	PPC_LL	r5,PT_REGS(r4)
 	toreal(r5)
 	PPC_LL	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
@@ -160,7 +125,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 #endif /* CONFIG_SMP */
 	/* enable use of FP after return */
 #ifdef CONFIG_PPC32
-	mfspr	r5,SPRN_SPRG_THREAD		/* current task's THREAD (phys) */
+	mfspr	r5,SPRN_SPRG_THREAD	/* current task's THREAD (phys) */
 	lwz	r4,THREAD_FPEXC_MODE(r5)
 	ori	r9,r9,MSR_FP		/* enable FP for current */
 	or	r9,r9,r4
@@ -172,9 +137,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 	or	r12,r12,r4
 	std	r12,_MSR(r1)
 #endif
-	lfd	fr0,THREAD_FPSCR(r5)
+	addi	r7,r5,THREAD_FPSTATE
+	lfd	fr0,FPSTATE_FPSCR(r7)
 	MTFSF_L(fr0)
-	REST_32FPVSRS(0, R4, R5)
+	REST_32FPVSRS(0, R4, R7)
 #ifndef CONFIG_SMP
 	subi	r4,r5,THREAD
 	fromreal(r4)
@@ -208,9 +174,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 	addi	r3,r3,THREAD	        /* want THREAD of task */
 	PPC_LL	r5,PT_REGS(r3)
 	PPC_LCMPI	0,r5,0
-	SAVE_32FPVSRS(0, R4 ,R3)
+	addi	r6,r3,THREAD_FPSTATE
+	SAVE_32FPVSRS(0, R4, R6)
 	mffs	fr0
-	stfd	fr0,THREAD_FPSCR(r3)
+	stfd	fr0,FPSTATE_FPSCR(r6)
 	beq	1f
 	PPC_LL	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
 	li	r3,MSR_FP|MSR_FE0|MSR_FE1