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, 3 insertions, 5 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 96d2fdf3aa9..7a281416aff 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1113,12 +1113,10 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 #ifdef CONFIG_VSX
 	current->thread.used_vsr = 0;
 #endif
-	memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
-	current->thread.fpscr.val = 0;
+	memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
 #ifdef CONFIG_ALTIVEC
-	memset(current->thread.vr, 0, sizeof(current->thread.vr));
-	memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
-	current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
+	memset(&current->thread.vr_state, 0, sizeof(current->thread.vr_state));
+	current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */
 	current->thread.vrsave = 0;
 	current->thread.used_vr = 0;
 #endif /* CONFIG_ALTIVEC */