[Top] [All Lists]

[PATCH] mips: set ST0_MX flag for MDMX

To: Ralf Baechle <>
Subject: [PATCH] mips: set ST0_MX flag for MDMX
From: Matt Turner <>
Date: Thu, 3 May 2012 18:40:45 -0400
Cc:, Matt Turner <>
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer; bh=lrybytZ9Y5B/xyXwFJf88y+WIuWRpBUs5DV+T5g4bB0=; b=0C4lkCl9m6428UxmIKWOsjv3a1Bnva5zk6EIp1QXGJfRqRT9UlW6yIajHdocX1x/1z P9Lvaj5/2QeIisSewIEGjhP4O67T5WRadez/4NkXMphnWcQrxe6oTQFBALImuSLlidGu tQ6l5pAivoMbbvmfJfTmirivsSXsKubdZp7nSTZ2WhQ2yaWi3WL5/yg8u1AlNP21Cfpa Mc8mvVqTDAJxJvVvLMw1ZVEuAICA4WMt5jJGSzGrJL/JttZu8nlG7TZlpFRpwCX7cyof mAPggSBHYA+PoJ3MWTJfcdtlBCPcc+pmdiAKA7xidOTtW03eFr86fCBKqHzf/VxO4oQ3 D7+Q==
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 <>
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:

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)
        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;

<Prev in Thread] Current Thread [Next in Thread>