MIPS: Move r2300 FP code from r2300_switch.S to r2300_fpu.S

Move _save_fp(), _restore_fp() & _init_fpu() out of r2300_switch.S &
into r2300_fpu.S. This logically places all FP-related asm code into
r2300_fpu.S & provides consistency with R4K after the preceding commit.

Besides cleaning up this will be useful for later patches which disable
FP support.

[[e-mail]: Fixed build issues reported by Arnd Bergmann
<[e-mail]>]

Signed-off-by: Paul Burton <[e-mail]>
Cc: [e-mail]
Patchwork: https://patchwork.linux-mips.org/patch/16238/
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/kernel/r2300_fpu.S

···
  * Copyright (c) 1998 Harald Koerfgen
  */
 #include <asm/asm.h>
+#include <asm/asmmacro.h>
 #include <asm/errno.h>
+#include <asm/export.h>
 #include <asm/fpregdef.h>
 #include <asm/mipsregs.h>
 #include <asm/asm-offsets.h>
···
 	PTR	9b+4,bad_stack;					\
 	.previous
 
-	.set	noreorder
 	.set	mips1
+
+/*
+ * Save a thread's fp context.
+ */
+LEAF(_save_fp)
+EXPORT_SYMBOL(_save_fp)
+	fpu_save_single a0, t1			# clobbers t1
+	jr	ra
+	END(_save_fp)
+
+/*
+ * Restore a thread's fp context.
+ */
+LEAF(_restore_fp)
+	fpu_restore_single a0, t1		# clobbers t1
+	jr	ra
+	END(_restore_fp)
+
+/*
+ * Load the FPU with signalling NANS.  This bit pattern we're using has
+ * the property that no matter whether considered as single or as double
+ * precision represents signaling NANS.
+ *
+ * The value to initialize fcr31 to comes in $a0.
+ */
+
+	.set push
+	SET_HARDFLOAT
+
+LEAF(_init_fpu)
+	mfc0	t0, CP0_STATUS
+	li	t1, ST0_CU1
+	or	t0, t1
+	mtc0	t0, CP0_STATUS
+
+	ctc1	a0, fcr31
+
+	li	t0, -1
+
+	mtc1	t0, $f0
+	mtc1	t0, $f1
+	mtc1	t0, $f2
+	mtc1	t0, $f3
+	mtc1	t0, $f4
+	mtc1	t0, $f5
+	mtc1	t0, $f6
+	mtc1	t0, $f7
+	mtc1	t0, $f8
+	mtc1	t0, $f9
+	mtc1	t0, $f10
+	mtc1	t0, $f11
+	mtc1	t0, $f12
+	mtc1	t0, $f13
+	mtc1	t0, $f14
+	mtc1	t0, $f15
+	mtc1	t0, $f16
+	mtc1	t0, $f17
+	mtc1	t0, $f18
+	mtc1	t0, $f19
+	mtc1	t0, $f20
+	mtc1	t0, $f21
+	mtc1	t0, $f22
+	mtc1	t0, $f23
+	mtc1	t0, $f24
+	mtc1	t0, $f25
+	mtc1	t0, $f26
+	mtc1	t0, $f27
+	mtc1	t0, $f28
+	mtc1	t0, $f29
+	mtc1	t0, $f30
+	mtc1	t0, $f31
+	jr	ra
+	END(_init_fpu)
+
+	.set pop
+
+	.set	noreorder
 
 /**
  * _save_fp_context() - save FP context from the FPU

arch/mips/kernel/r2300_switch.S

···
 	move	v0, a0
 	jr	ra
 	END(resume)
-
-/*
- * Save a thread's fp context.
- */
-LEAF(_save_fp)
-EXPORT_SYMBOL(_save_fp)
-	fpu_save_single a0, t1			# clobbers t1
-	jr	ra
-	END(_save_fp)
-
-/*
- * Restore a thread's fp context.
- */
-LEAF(_restore_fp)
-	fpu_restore_single a0, t1		# clobbers t1
-	jr	ra
-	END(_restore_fp)
-
-/*
- * Load the FPU with signalling NANS.  This bit pattern we're using has
- * the property that no matter whether considered as single or as double
- * precision represents signaling NANS.
- *
- * The value to initialize fcr31 to comes in $a0.
- */
-
-	.set push
-	SET_HARDFLOAT
-
-LEAF(_init_fpu)
-	mfc0	t0, CP0_STATUS
-	li	t1, ST0_CU1
-	or	t0, t1
-	mtc0	t0, CP0_STATUS
-
-	ctc1	a0, fcr31
-
-	li	t0, -1
-
-	mtc1	t0, $f0
-	mtc1	t0, $f1
-	mtc1	t0, $f2
-	mtc1	t0, $f3
-	mtc1	t0, $f4
-	mtc1	t0, $f5
-	mtc1	t0, $f6
-	mtc1	t0, $f7
-	mtc1	t0, $f8
-	mtc1	t0, $f9
-	mtc1	t0, $f10
-	mtc1	t0, $f11
-	mtc1	t0, $f12
-	mtc1	t0, $f13
-	mtc1	t0, $f14
-	mtc1	t0, $f15
-	mtc1	t0, $f16
-	mtc1	t0, $f17
-	mtc1	t0, $f18
-	mtc1	t0, $f19
-	mtc1	t0, $f20
-	mtc1	t0, $f21
-	mtc1	t0, $f22
-	mtc1	t0, $f23
-	mtc1	t0, $f24
-	mtc1	t0, $f25
-	mtc1	t0, $f26
-	mtc1	t0, $f27
-	mtc1	t0, $f28
-	mtc1	t0, $f29
-	mtc1	t0, $f30
-	mtc1	t0, $f31
-	jr	ra
-	END(_init_fpu)
-
-	.set pop