MIPS: nofpu and nodsp only affect CPU0

The "nofpu" and "nodsp" kernel command line options currently do not
affect CPUs that are brought online later in the boot process or
hotplugged at runtime.  It is desirable to apply the nofpu/nodsp options
to all CPUs in the system, so that surprising results are not seen when
a process migrates from one CPU to another.

[Ralf: Moved definitions of mips_fpu_disabled, fpu_disable,
mips_dsp_disabled and dsp_disable from setup.c to cpu-probe.c to allow
making mips_fpu_disabled and mips_dsp_disabled static.]

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: http://patchwork.linux-mips.org/patch/1169/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index be5bb16be4e..3562b854f2c 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -125,6 +125,30 @@ static int __init wait_disable(char *s)
 
 __setup("nowait", wait_disable);
 
+static int __cpuinitdata mips_fpu_disabled;
+
+static int __init fpu_disable(char *s)
+{
+	cpu_data[0].options &= ~MIPS_CPU_FPU;
+	mips_fpu_disabled = 1;
+
+	return 1;
+}
+
+__setup("nofpu", fpu_disable);
+
+int __cpuinitdata mips_dsp_disabled;
+
+static int __init dsp_disable(char *s)
+{
+	cpu_data[0].ases &= ~MIPS_ASE_DSP;
+	mips_dsp_disabled = 1;
+
+	return 1;
+}
+
+__setup("nodsp", dsp_disable);
+
 void __init check_wait(void)
 {
 	struct cpuinfo_mips *c = &current_cpu_data;
@@ -982,6 +1006,12 @@ __cpuinit void cpu_probe(void)
 	 */
 	BUG_ON(current_cpu_type() != c->cputype);
 
+	if (mips_fpu_disabled)
+		c->options &= ~MIPS_CPU_FPU;
+
+	if (mips_dsp_disabled)
+		c->ases &= ~MIPS_ASE_DSP;
+
 	if (c->options & MIPS_CPU_FPU) {
 		c->fpu_id = cpu_get_fpu_id();