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, 22 insertions, 19 deletions

diff --git a/arch/powerpc/kernel/tm.S b/arch/powerpc/kernel/tm.S
index cd809eaa8b5c..761af4f0a632 100644
--- a/arch/powerpc/kernel/tm.S
+++ b/arch/powerpc/kernel/tm.S
@@ -12,16 +12,15 @@
 #include <asm/reg.h>
 
 #ifdef CONFIG_VSX
-/* See fpu.S, this is very similar but to save/restore checkpointed FPRs/VSRs */
-#define __SAVE_32FPRS_VSRS_TRANSACT(n,c,base)	\
+/* See fpu.S, this is borrowed from there */
+#define __SAVE_32FPRS_VSRS(n,c,base)		\
 BEGIN_FTR_SECTION				\
 	b	2f;				\
 END_FTR_SECTION_IFSET(CPU_FTR_VSX);		\
-	SAVE_32FPRS_TRANSACT(n,base);		\
+	SAVE_32FPRS(n,base);			\
 	b	3f;				\
-2:	SAVE_32VSRS_TRANSACT(n,c,base);		\
+2:	SAVE_32VSRS(n,c,base);			\
 3:
-/* ...and this is just plain borrowed from there. */
 #define __REST_32FPRS_VSRS(n,c,base)		\
 BEGIN_FTR_SECTION				\
 	b	2f;				\
@@ -31,11 +30,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX);		\
 2:	REST_32VSRS(n,c,base);			\
 3:
 #else
-#define __SAVE_32FPRS_VSRS_TRANSACT(n,c,base) SAVE_32FPRS_TRANSACT(n, base)
-#define __REST_32FPRS_VSRS(n,c,base)	      REST_32FPRS(n, base)
+#define __SAVE_32FPRS_VSRS(n,c,base)	SAVE_32FPRS(n, base)
+#define __REST_32FPRS_VSRS(n,c,base)	REST_32FPRS(n, base)
 #endif
-#define SAVE_32FPRS_VSRS_TRANSACT(n,c,base) \
-	__SAVE_32FPRS_VSRS_TRANSACT(n,__REG_##c,__REG_##base)
+#define SAVE_32FPRS_VSRS(n,c,base) \
+	__SAVE_32FPRS_VSRS(n,__REG_##c,__REG_##base)
 #define REST_32FPRS_VSRS(n,c,base) \
 	__REST_32FPRS_VSRS(n,__REG_##c,__REG_##base)
 
@@ -157,10 +156,11 @@ _GLOBAL(tm_reclaim)
 	andis.		r0, r4, MSR_VEC@h
 	beq	dont_backup_vec
 
-	SAVE_32VRS_TRANSACT(0, r6, r3)	/* r6 scratch, r3 thread */
+	addi	r7, r3, THREAD_TRANSACT_VRSTATE
+	SAVE_32VRS(0, r6, r7)	/* r6 scratch, r7 transact vr state */
 	mfvscr	vr0
-	li	r6, THREAD_TRANSACT_VSCR
-	stvx	vr0, r3, r6
+	li	r6, VRSTATE_VSCR
+	stvx	vr0, r7, r6
 dont_backup_vec:
 	mfspr	r0, SPRN_VRSAVE
 	std	r0, THREAD_TRANSACT_VRSAVE(r3)
@@ -168,10 +168,11 @@ dont_backup_vec:
 	andi.	r0, r4, MSR_FP
 	beq	dont_backup_fp
 
-	SAVE_32FPRS_VSRS_TRANSACT(0, R6, R3)	/* r6 scratch, r3 thread */
+	addi	r7, r3, THREAD_TRANSACT_FPSTATE
+	SAVE_32FPRS_VSRS(0, R6, R7)	/* r6 scratch, r7 transact fp state */
 
 	mffs    fr0
-	stfd    fr0,THREAD_TRANSACT_FPSCR(r3)
+	stfd    fr0,FPSTATE_FPSCR(r7)
 
 dont_backup_fp:
 	/* The moment we treclaim, ALL of our GPRs will switch
@@ -358,10 +359,11 @@ _GLOBAL(tm_recheckpoint)
 	andis.	r0, r4, MSR_VEC@h
 	beq	dont_restore_vec
 
-	li	r5, THREAD_VSCR
-	lvx	vr0, r3, r5
+	addi	r8, r3, THREAD_VRSTATE
+	li	r5, VRSTATE_VSCR
+	lvx	vr0, r8, r5
 	mtvscr	vr0
-	REST_32VRS(0, r5, r3)			/* r5 scratch, r3 THREAD ptr */
+	REST_32VRS(0, r5, r8)			/* r5 scratch, r8 ptr */
 dont_restore_vec:
 	ld	r5, THREAD_VRSAVE(r3)
 	mtspr	SPRN_VRSAVE, r5
@@ -370,9 +372,10 @@ dont_restore_vec:
 	andi.	r0, r4, MSR_FP
 	beq	dont_restore_fp
 
-	lfd	fr0, THREAD_FPSCR(r3)
+	addi	r8, r3, THREAD_FPSTATE
+	lfd	fr0, FPSTATE_FPSCR(r8)
 	MTFSF_L(fr0)
-	REST_32FPRS_VSRS(0, R4, R3)
+	REST_32FPRS_VSRS(0, R4, R8)
 
 dont_restore_fp:
 	mtmsr	r6				/* FP/Vec off again! */