MIPS: kernel: r4k_switch: Add support for MIPS R6

Add the MIPS R6 related preprocessor definitions for save/restore
FPU related functions. We also set the appropriate ISA level
so the final return instruction "jr ra" will produce the correct
opcode on R6.
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

arch/mips/include/asm/asmmacro.h

@@ -104,7 +104,8 @@
 	.endm
 
 	.macro	fpu_save_double thread status tmp
-#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
+#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2) || \
+		defined(CONFIG_CPU_MIPS32_R6)
 	sll	\tmp, \status, 5
 	bgez	\tmp, 10f
 	fpu_save_16odd \thread
@@ -160,7 +161,8 @@
 	.endm
 
 	.macro	fpu_restore_double thread status tmp
-#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
+#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2) || \
+		defined(CONFIG_CPU_MIPS32_R6)
 	sll	\tmp, \status, 5
 	bgez	\tmp, 10f				# 16 register mode?
 
@@ -170,16 +172,16 @@
 	fpu_restore_16even \thread \tmp
 	.endm
 
-#ifdef CONFIG_CPU_MIPSR2
+#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)
 	.macro	_EXT	rd, rs, p, s
 	ext	\rd, \rs, \p, \s
 	.endm
-#else /* !CONFIG_CPU_MIPSR2 */
+#else /* !CONFIG_CPU_MIPSR2 || !CONFIG_CPU_MIPSR6 */
 	.macro	_EXT	rd, rs, p, s
 	srl	\rd, \rs, \p
 	andi	\rd, \rd, (1 << \s) - 1
 	.endm
-#endif /* !CONFIG_CPU_MIPSR2 */
+#endif /* !CONFIG_CPU_MIPSR2 || !CONFIG_CPU_MIPSR6 */
 
 /*
  * Temporary until all gas have MT ASE support

arch/mips/kernel/r4k_switch.S

@@ -115,7 +115,8 @@
  * Save a thread's fp context.
  */
 LEAF(_save_fp)
-#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
+#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2) || \
+		defined(CONFIG_CPU_MIPS32_R6)
 	mfc0	t0, CP0_STATUS
 #endif
 	fpu_save_double a0 t0 t1		# clobbers t1
@@ -126,7 +127,8 @@ LEAF(_save_fp)
  * Restore a thread's fp context.
  */
 LEAF(_restore_fp)
-#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
+#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2) || \
+		defined(CONFIG_CPU_MIPS32_R6)
 	mfc0	t0, CP0_STATUS
 #endif
 	fpu_restore_double a0 t0 t1		# clobbers t1
@@ -240,9 +242,9 @@ LEAF(_init_fpu)
 	mtc1	t1, $f30
 	mtc1	t1, $f31
 
-#ifdef CONFIG_CPU_MIPS32_R2
+#if defined(CONFIG_CPU_MIPS32_R2) || defined(CONFIG_CPU_MIPS32_R6)
 	.set    push
-	.set    mips32r2
+	.set    MIPS_ISA_LEVEL_RAW
 	.set	fp=64
 	sll     t0, t0, 5			# is Status.FR set?
 	bgez    t0, 1f				# no: skip setting upper 32b
@@ -280,9 +282,9 @@ LEAF(_init_fpu)
 	mthc1   t1, $f30
 	mthc1   t1, $f31
 1:	.set    pop
-#endif /* CONFIG_CPU_MIPS32_R2 */
+#endif /* CONFIG_CPU_MIPS32_R2 || CONFIG_CPU_MIPS32_R6 */
 #else
-	.set	arch=r4000
+	.set	MIPS_ISA_ARCH_LEVEL_RAW
 	dmtc1	t1, $f0
 	dmtc1	t1, $f2
 	dmtc1	t1, $f4