File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/sparc/lib/VISsave.S b/arch/sparc/lib/VISsave.S
new file mode 100644
index 0000000..62c2647
--- /dev/null
+++ b/arch/sparc/lib/VISsave.S
@@ -0,0 +1,81 @@
+/*
+ * VISsave.S: Code for saving FPU register state for
+ *            VIS routines. One should not call this directly,
+ *            but use macros provided in <asm/visasm.h>.
+ *
+ * Copyright (C) 1998 Jakub Jelinek (jj@ultra.linux.cz)
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/asi.h>
+#include <asm/page.h>
+#include <asm/ptrace.h>
+#include <asm/visasm.h>
+#include <asm/thread_info.h>
+
+	/* On entry: %o5=current FPRS value, %g7 is callers address */
+	/* May clobber %o5, %g1, %g2, %g3, %g7, %icc, %xcc */
+
+	/* Nothing special need be done here to handle pre-emption, this
+	 * FPU save/restore mechanism is already preemption safe.
+	 */
+	.text
+	.align		32
+ENTRY(VISenter)
+	ldub		[%g6 + TI_FPDEPTH], %g1
+	brnz,a,pn	%g1, 1f
+	 cmp		%g1, 1
+	stb		%g0, [%g6 + TI_FPSAVED]
+	stx		%fsr, [%g6 + TI_XFSR]
+9:	jmpl		%g7 + %g0, %g0
+	 nop
+1:	bne,pn		%icc, 2f
+
+	 srl		%g1, 1, %g1
+vis1:	ldub		[%g6 + TI_FPSAVED], %g3
+	stx		%fsr, [%g6 + TI_XFSR]
+	or		%g3, %o5, %g3
+	stb		%g3, [%g6 + TI_FPSAVED]
+	rd		%gsr, %g3
+	clr		%g1
+	ba,pt		%xcc, 3f
+
+	 stx		%g3, [%g6 + TI_GSR]
+2:	add		%g6, %g1, %g3
+	mov		FPRS_DU | FPRS_DL | FPRS_FEF, %o5
+	sll		%g1, 3, %g1
+	stb		%o5, [%g3 + TI_FPSAVED]
+	rd		%gsr, %g2
+	add		%g6, %g1, %g3
+	stx		%g2, [%g3 + TI_GSR]
+
+	add		%g6, %g1, %g2
+	stx		%fsr, [%g2 + TI_XFSR]
+	sll		%g1, 5, %g1
+3:	andcc		%o5, FPRS_DL|FPRS_DU, %g0
+	be,pn		%icc, 9b
+	 add		%g6, TI_FPREGS, %g2
+	andcc		%o5, FPRS_DL, %g0
+
+	be,pn		%icc, 4f
+	 add		%g6, TI_FPREGS+0x40, %g3
+	membar		#Sync
+	stda		%f0, [%g2 + %g1] ASI_BLK_P
+	stda		%f16, [%g3 + %g1] ASI_BLK_P
+	membar		#Sync
+	andcc		%o5, FPRS_DU, %g0
+	be,pn		%icc, 5f
+4:	 add		%g1, 128, %g1
+	membar		#Sync
+	stda		%f32, [%g2 + %g1] ASI_BLK_P
+
+	stda		%f48, [%g3 + %g1] ASI_BLK_P
+5:	membar		#Sync
+	ba,pt		%xcc, 80f
+	 nop
+
+	.align		32
+80:	jmpl		%g7 + %g0, %g0
+	 nop
+ENDPROC(VISenter)