nds32: Enable FPU if the version of CPU supported

Some version of Andes core support FPU coprocessor,
if this is the case, and toolchain support FPU instruction set,
we should enable it at low level initialization time.

Signed-off-by: Kuan-Yu Kuo <ken.kuoky@gmail.com>
Cc: Macpaul Lin <macpaul@gmail.com>

diff --git a/arch/nds32/cpu/n1213/ag101/lowlevel_init.S b/arch/nds32/cpu/n1213/ag101/lowlevel_init.S
index 55985cf..021de86 100644 (file)
--- a/arch/nds32/cpu/n1213/ag101/lowlevel_init.S
+++ b/arch/nds32/cpu/n1213/ag101/lowlevel_init.S
@@ -98,6 +98,11 @@ lowlevel_init:
        led     0x10
        jal     remap
 
+#if (defined(NDS32_EXT_FPU_DP) || defined(NDS32_EXT_FPU_SP))
+       led     0x1f
+       jal     enable_fpu
+#endif
+
        led     0x20
        ret     $r10
 
@@ -234,6 +239,27 @@ relo_base:
 2:
        ret
 
+       /*
+        * enable_fpu:
+        *  Some of Andes CPU version support FPU coprocessor, if so,
+        *  and toolchain support FPU instruction set, we should enable it.
+        */
+#if (defined(NDS32_EXT_FPU_DP) || defined(NDS32_EXT_FPU_SP))
+enable_fpu:
+       mfsr    $r0, $CPU_VER     /* enable FPU if it exists */
+       srli    $r0, $r0, 3
+       andi    $r0, $r0, 1
+       beqz    $r0, 1f           /* skip if no COP */
+       mfsr    $r0, $FUCOP_EXIST
+       srli    $r0, $r0, 31
+       beqz    $r0, 1f           /* skip if no FPU */
+       mfsr    $r0, $FUCOP_CTL
+       ori     $r0, $r0, 1
+       mtsr    $r0, $FUCOP_CTL
+1:
+       ret
+#endif
+
 .globl show_led
 show_led:
     li      $r8, (CONFIG_DEBUG_LED)

diff --git a/arch/nds32/cpu/n1213/ag102/lowlevel_init.S b/arch/nds32/cpu/n1213/ag102/lowlevel_init.S
index d842afa..d3b9e16 100644 (file)
--- a/arch/nds32/cpu/n1213/ag102/lowlevel_init.S
+++ b/arch/nds32/cpu/n1213/ag102/lowlevel_init.S
@@ -114,6 +114,11 @@ lowlevel_init:
        led     0x20
        jal     remap
 
+#if (defined(NDS32_EXT_FPU_DP) || defined(NDS32_EXT_FPU_SP))
+       led     0x2f
+       jal     enable_fpu
+#endif
+
        led     0x30
        ret     $r10
 
@@ -289,6 +294,27 @@ relo_base:
 2:
        ret
 
+       /*
+        * enable_fpu:
+        *  Some of Andes CPU version support FPU coprocessor, if so,
+        *  and toolchain support FPU instruction set, we should enable it.
+        */
+#if (defined(NDS32_EXT_FPU_DP) || defined(NDS32_EXT_FPU_SP))
+enable_fpu:
+       mfsr    $r0, $CPU_VER     /* enable FPU if it exists */
+       srli    $r0, $r0, 3
+       andi    $r0, $r0, 1
+       beqz    $r0, 1f           /* skip if no COP */
+       mfsr    $r0, $FUCOP_EXIST
+       srli    $r0, $r0, 31
+       beqz    $r0, 1f           /* skip if no FPU */
+       mfsr    $r0, $FUCOP_CTL
+       ori     $r0, $r0, 1
+       mtsr    $r0, $FUCOP_CTL
+1:
+       ret
+#endif
+
 .globl show_led
 show_led:
     li      $r8, (CONFIG_DEBUG_LED)