MIPS: detect presence of MAARs
Detect the presence of MAAR using the MRP bit in Config5, and record
that presence using a CPU option bit. A cpu_has_maar macro will then
allow code to conditionalise upon the presence of MAARs.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7330/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index eeb5400..e079598 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -35,6 +35,9 @@
#ifndef cpu_has_rixiex
#define cpu_has_rixiex (cpu_data[0].options & MIPS_CPU_RIXIEX)
#endif
+#ifndef cpu_has_maar
+#define cpu_has_maar (cpu_data[0].options & MIPS_CPU_MAAR)
+#endif
/*
* For the moment we don't consider R6000 and R8000 so we can assume that
diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index 7ba2a03..dfdc77e 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -367,6 +367,7 @@
#define MIPS_CPU_EVA 0x80000000ull /* CPU supports Enhanced Virtual Addressing */
#define MIPS_CPU_HTW 0x100000000ull /* CPU support Hardware Page Table Walker */
#define MIPS_CPU_RIXIEX 0x200000000ull /* CPU has unique exception codes for {Read, Execute}-Inhibit exceptions */
+#define MIPS_CPU_MAAR 0x400000000ull /* MAAR(I) registers are present */
/*
* CPU ASE encodings
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 66b8fe9..e34b10b 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -405,6 +405,8 @@
if (config5 & MIPS_CONF5_EVA)
c->options |= MIPS_CPU_EVA;
+ if (config5 & MIPS_CONF5_MRP)
+ c->options |= MIPS_CPU_MAAR;
return config5 & MIPS_CONF_M;
}