[RFC] activate performance counter registers on Netlogic XLR chip

[Hillf Danton <dhillf@gmail.com>]

On Netlogic XLR chip two pairs of performance counter registers,

   perf_ctrl0: c0 reg 25 sel 0, perf_cntr0: c0 reg 25 sel 1
   perf_ctrl1: c0 reg 25 sel 2, perf_cntr0: c0 reg 25 sel 3

provide a means for software to count processor events.

At most 64 events can be counted, such as,
   Instruction fetched and retired, branch instructions
   Instruction and Data Cache Unit statistics
   Instruction and Data TLB statistics
   Instruction Fetch Unit statistics
   Instruction Execution Unit statistics
   Load/store Unit statistics
   Cycle Count

They are activated based on the model of mips/74k, and
any comment is appreciated.

Thanks

Signed-off-by: Hillf Danton <dhillf@gmail.com>
---

--- a/arch/mips/oprofile/Makefile       Tue Jul 12 21:50:26 2011
+++ b/arch/mips/oprofile/Makefile       Sat Oct  1 13:44:28 2011
@@ -16,3 +16,4 @@ oprofile-$(CONFIG_CPU_R10000)         += op_mod
 oprofile-$(CONFIG_CPU_SB1)             += op_model_mipsxx.o
 oprofile-$(CONFIG_CPU_RM9000)          += op_model_rm9000.o
 oprofile-$(CONFIG_CPU_LOONGSON2)       += op_model_loongson2.o
+oprofile-$(CONFIG_CPU_XLR)             += op_model_mipsxx.o
--- a/arch/mips/oprofile/common.c       Tue Jul 12 21:50:26 2011
+++ b/arch/mips/oprofile/common.c       Sat Oct  1 13:45:23 2011
@@ -89,6 +89,7 @@ int __init oprofile_arch_init(struct opr
        case CPU_R10000:
        case CPU_R12000:
        case CPU_R14000:
+       case CPU_XLR:
                lmodel = &op_model_mipsxx_ops;
                break;

--- a/arch/mips/oprofile/op_model_mipsxx.c      Sat May 14 15:21:02 2011
+++ b/arch/mips/oprofile/op_model_mipsxx.c      Sat Oct  1 13:50:26 2011
@@ -19,7 +19,11 @@
 #define M_PERFCTL_SUPERVISOR           (1UL      <<  2)
 #define M_PERFCTL_USER                 (1UL      <<  3)
 #define M_PERFCTL_INTERRUPT_ENABLE     (1UL      <<  4)
+#ifdef CONFIG_CPU_XLR
+#define M_PERFCTL_EVENT(event)         ((((event) & 0x3f)  << 5) | 0x2001)
+#else
 #define M_PERFCTL_EVENT(event)         (((event) & 0x3ff)  << 5)
+#endif
 #define M_PERFCTL_VPEID(vpe)           ((vpe)    << 16)
 #define M_PERFCTL_MT_EN(filter)                ((filter) << 20)
 #define    M_TC_EN_ALL                 M_PERFCTL_MT_EN(0)
@@ -264,6 +268,7 @@ static inline int n_counters(void)

        switch (current_cpu_type()) {
        case CPU_R10000:
+       case CPU_XLR:
                counters = 2;
                break;

@@ -365,6 +370,9 @@ static int __init mipsxx_init(void)
                op_model_mipsxx_ops.cpu_type = "mips/sb1";
                break;

+       case CPU_XLR:
+               op_model_mipsxx_ops.cpu_type = "mips/xlr";
+               break;
        default:
                printk(KERN_ERR "Profiling unsupported for this CPU\n");