ARC: ARCv2: handle DSP presence in HW

[platform/kernel/u-boot.git] / arch / arc / lib / start.S

diff --git a/arch/arc/lib/start.S b/arch/arc/lib/start.S
index 8c744f5..016ae85 100644 (file)
--- a/arch/arc/lib/start.S
+++ b/arch/arc/lib/start.S
@@ -61,6 +61,21 @@ ENTRY(_start)
 1:
 #endif
 
+#ifdef CONFIG_ISA_ARCV2
+       ; In case of DSP extension presence in HW some instructions
+       ; (related to integer multiply, multiply-accumulate, and divide
+       ; operation) executes on this DSP execution unit. So their
+       ; execution will depend on dsp configuration register (DSP_CTRL)
+       ; As we want these instructions to execute the same way regardless
+       ; of DSP presence we need to set DSP_CTRL properly.
+       lr      r5, [ARC_AUX_DSP_BUILD]
+       bmsk    r5, r5, 7
+       breq    r5, 0, 1f
+       mov     r5, 0
+       sr      r5, [ARC_AUX_DSP_CTRL]
+1:
+#endif
+
 #ifdef __ARC_UNALIGNED__
        /*
         * Enable handling of unaligned access in the CPU as by default