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[PATCH] mips: set ST0_MX flag for MDMX

To: Ralf Baechle <ralf@linux-mips.org>
Subject: [PATCH] mips: set ST0_MX flag for MDMX
From: Matt Turner <mattst88@gmail.com>
Date: Thu, 3 May 2012 18:40:45 -0400
Cc: linux-mips@linux-mips.org, Matt Turner <mattst88@gmail.com>
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Sender: linux-mips-bounce@linux-mips.org
As the comment in commit 3301edcb says, DSP and MDMX share the same
config flag bit.

Without this set, MDMX instructions cause Illegal instruction errors.

Signed-off-by: Matt Turner <mattst88@gmail.com>
---
Is MDMX implemented by anything other than some Broadcom CPUs? Is it
totally replaced by DSP?

I had a terrible time finding any documentation on it (which is annoying
because Volume IV-b covering MDMX is referenced by all the MIPS64 documents.)
but finally found a copy here: www.enlight.ru/docs/cpu/risc/mips/MDMXspec.pdf

If it's dead, it's too bad because it's a pretty cool ISA.

 arch/mips/kernel/traps.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index cfdaaa4..89ead75 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1548,7 +1548,7 @@ void __cpuinit per_cpu_trap_init(void)
 #endif
        if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
                status_set |= ST0_XX;
-       if (cpu_has_dsp)
+       if (cpu_has_dsp || cpu_has_mdmx)
                status_set |= ST0_MX;
 
        
change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
-- 
1.7.3.4


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