nios2: zap dly_clks

The dly_clks() in start.S is no use after switching to
generic timer. Remove it.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Marek Vasut <marex@denx.de>
master
Thomas Chou 9 years ago
parent e6500f86a6
commit 651389a055
  1. 33
      arch/nios2/cpu/start.S

@ -175,39 +175,6 @@ relocate_code:
callr r8
ret
/*
* dly_clks -- Nios2 (like Nios1) doesn't have a timebase in
* the core. For simple delay loops, we do our best by counting
* instruction cycles.
*
* Instruction performance varies based on the core. For cores
* with icache and static/dynamic branch prediction (II/f, II/s):
*
* Normal ALU (e.g. add, cmp, etc): 1 cycle
* Branch (correctly predicted, taken): 2 cycles
* Negative offset is predicted (II/s).
*
* For cores without icache and no branch prediction (II/e):
*
* Normal ALU (e.g. add, cmp, etc): 6 cycles
* Branch (no prediction): 6 cycles
*
* For simplicity, if an instruction cache is implemented we
* assume II/f or II/s. Otherwise, we use the II/e.
*
*/
.globl dly_clks
dly_clks:
#if (CONFIG_SYS_ICACHE_SIZE > 0)
subi r4, r4, 3 /* 3 clocks/loop */
#else
subi r4, r4, 12 /* 12 clocks/loop */
#endif
bge r4, r0, dly_clks
ret
.data
.globl version_string

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