MIPS: Probe for MIPS MT perf counters per TC

Processors implementing the MIPS MT ASE may have performance counters
implemented per core or per TC. Processors implemented by MIPS
Technologies signify presence per TC through a bit in the implementation
specific Config7 register. Currently the code which probes for their
presence blindly reads a magic number corresponding to this bit, despite
it potentially having a different meaning in the CPU implementation.

Since CPU features are generally detected by cpu-probe.c, perform the
detection here instead. Introduce cpu_set_mt_per_tc_perf which checks
the bit in config7 and call it from MIPS CPUs known to implement this
bit and the MT ASE, specifically, the 34K, 1004K and interAptiv.

Once the presence of the per-tc counter is indicated in cpu_data, tests
for it can be updated to use this flag.

Suggested-by: James Hogan <jhogan@kernel.org>
Signed-off-by: Matt Redfearn <matt.redfearn@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Matt Redfearn <matt.redfearn@mips.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Maciej W. Rozycki <macro@mips.com>
Cc: linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/19136/
Signed-off-by: James Hogan <jhogan@kernel.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index f65859784a4c..ae461d91cd1f 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -685,6 +685,11 @@
 #define MIPS_CONF7_IAR		(_ULCAST_(1) << 10)
 #define MIPS_CONF7_AR		(_ULCAST_(1) << 16)
 
+/* Config7 Bits specific to MIPS Technologies. */
+
+/* Performance counters implemented Per TC */
+#define MTI_CONF7_PTC		(_ULCAST_(1) << 19)
+
 /* WatchLo* register definitions */
 #define MIPS_WATCHLO_IRW	(_ULCAST_(0x7) << 0)