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| author | Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> | 2020-04-22 18:33:21 +0300 |
|---|---|---|
| committer | Alexey Brodkin <abrodkin@synopsys.com> | 2020-04-27 11:20:25 +0300 |
| commit | 61c151693ba7129fbe7864a8486bca4e36046d19 (patch) | |
| tree | f8d49b2b89ee013724b5f3dbf83698b4bb1c5410 | |
| parent | d202f67db0771247de562af5d6a5df778702857b (diff) | |
| download | u-boot-61c151693ba7129fbe7864a8486bca4e36046d19.zip u-boot-61c151693ba7129fbe7864a8486bca4e36046d19.tar.gz u-boot-61c151693ba7129fbe7864a8486bca4e36046d19.tar.bz2 | |
ARC: ARCv2: handle DSP presence in HW
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.
NOTE:
we do the same adjustments in Linux kernel, see in kernel tree:
commit 4827d0cf744e ("ARC: handle DSP presence in HW")
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
| -rw-r--r-- | arch/arc/include/asm/arcregs.h | 1 | ||||
| -rw-r--r-- | arch/arc/lib/start.S | 15 |
2 files changed, 16 insertions, 0 deletions
diff --git a/arch/arc/include/asm/arcregs.h b/arch/arc/include/asm/arcregs.h index fff6591..f3cd4a8 100644 --- a/arch/arc/include/asm/arcregs.h +++ b/arch/arc/include/asm/arcregs.h @@ -100,6 +100,7 @@ /* DSP-extensions related auxiliary registers */ #define ARC_AUX_DSP_BUILD 0x7A +#define ARC_AUX_DSP_CTRL 0x59F /* ARC Subsystems related auxiliary registers */ #define ARC_AUX_SUBSYS_BUILD 0xF0 diff --git a/arch/arc/lib/start.S b/arch/arc/lib/start.S index 8c744f5..016ae85 100644 --- 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 |