MIPS: Probe for presence of KScratch registers.
Probe c0_config4 for KScratch registers and report them in /proc/cpuinfo.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1877/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h
index b39def3..c454550 100644
--- a/arch/mips/include/asm/cpu-info.h
+++ b/arch/mips/include/asm/cpu-info.h
@@ -78,6 +78,7 @@
unsigned int watch_reg_use_cnt; /* Usable by ptrace */
#define NUM_WATCH_REGS 4
u16 watch_reg_masks[NUM_WATCH_REGS];
+ unsigned int kscratch_mask; /* Usable KScratch mask. */
} __attribute__((aligned(SMP_CACHE_BYTES)));
extern struct cpuinfo_mips cpu_data[];
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 68dae7b..f65d4c8 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -739,6 +739,8 @@
&& cpu_has_tlb)
c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
+ c->kscratch_mask = (config4 >> 16) & 0xff;
+
return config4 & MIPS_CONF_M;
}
diff --git a/arch/mips/kernel/proc.c b/arch/mips/kernel/proc.c
index 4195abb..e309665 100644
--- a/arch/mips/kernel/proc.c
+++ b/arch/mips/kernel/proc.c
@@ -74,6 +74,8 @@
);
seq_printf(m, "shadow register sets\t: %d\n",
cpu_data[n].srsets);
+ seq_printf(m, "kscratch registers\t: %d\n",
+ hweight8(cpu_data[n].kscratch_mask));
seq_printf(m, "core\t\t\t: %d\n", cpu_data[n].core);
sprintf(fmt, "VCE%%c exceptions\t\t: %s\n",
