arm: ipi raise/start/end tracing

Add tracepoints for IPI raise events, and start and end of the
ipi handler.

Used to inspect the source of CPU wake-ups which are not already
traced - all other reasons for a CPU to wake-up are already
covered.

Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Jon Medhurst <tixy@linaro.org>

diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 5919eb451bb9840590091c3d26a922bd65b1d005..80cd1ac1e0dcdcb0a3326be85a09f69413ef5587 100644 (file)
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -46,6 +46,9 @@
 #include <asm/virt.h>
 #include <asm/mach/arch.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/arm-ipi.h>
+
 /*
  * as from 2.5, kernels no longer have an init_tasks structure
  * so we need some other way of telling a new secondary core
@@ -604,6 +607,7 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
        if (ipinr < NR_IPI)
                __inc_irq_stat(cpu, ipi_irqs[ipinr]);
 
+       trace_arm_ipi_entry(ipinr);
        switch (ipinr) {
        case IPI_WAKEUP:
                break;
@@ -643,6 +647,7 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
                       cpu, ipinr);
                break;
        }
+       trace_arm_ipi_exit(ipinr);
        set_irq_regs(old_regs);
 }
 

diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 19ceaa60e0f45c755fd67d840e8ee90de320d1ca..5dc511c587222c0f537cf33d4a28c999b680c8bb 100644 (file)
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -41,6 +41,7 @@
 #include <linux/slab.h>
 #include <linux/irqchip/chained_irq.h>
 #include <linux/irqchip/arm-gic.h>
+#include <trace/events/arm-ipi.h>
 
 #include <asm/irq.h>
 #include <asm/exception.h>
@@ -649,8 +650,10 @@ void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
        unsigned long map = 0;
 
        /* Convert our logical CPU mask into a physical one. */
-       for_each_cpu(cpu, mask)
+       for_each_cpu(cpu, mask) {
+               trace_arm_ipi_send(irq, cpu);
                map |= gic_cpu_map[cpu];
+       }
 
        /*
         * Ensure that stores to Normal memory are visible to the

diff --git a/include/trace/events/arm-ipi.h b/include/trace/events/arm-ipi.h
new file mode 100644 (file)
index 0000000..5d3bd21
--- /dev/null
+++ b/include/trace/events/arm-ipi.h
@@ -0,0 +1,100 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM arm-ipi
+
+#if !defined(_TRACE_ARM_IPI_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_ARM_IPI_H
+
+#include <linux/tracepoint.h>
+
+#define show_arm_ipi_name(val)                         \
+       __print_symbolic(val,                           \
+                        { 0, "IPI_WAKEUP" },           \
+                        { 1, "IPI_TIMER" },            \
+                        { 2, "IPI_RESCHEDULE" },               \
+                        { 3, "IPI_CALL_FUNC" },                \
+                        { 4, "IPI_CALL_FUNC_SINGLE" },         \
+                        { 5, "IPI_CPU_STOP" }, \
+                        { 6, "IPI_COMPLETION" },               \
+                        { 7, "IPI_CPU_BACKTRACE" })
+
+DECLARE_EVENT_CLASS(arm_ipi,
+
+       TP_PROTO(unsigned int ipi_nr),
+
+       TP_ARGS(ipi_nr),
+
+       TP_STRUCT__entry(
+               __field(        unsigned int,   ipi     )
+       ),
+
+       TP_fast_assign(
+               __entry->ipi = ipi_nr;
+       ),
+
+       TP_printk("ipi=%u [action=%s]", __entry->ipi,
+               show_arm_ipi_name(__entry->ipi))
+);
+
+/**
+ * arm_ipi_entry - called in the arm-generic ipi handler immediately before
+ *                 entering ipi-type handler
+ * @ipi_nr:  ipi number
+ *
+ * When used in combination with the arm_ipi_exit tracepoint
+ * we can determine the ipi handler runtine.
+ */
+DEFINE_EVENT(arm_ipi, arm_ipi_entry,
+
+       TP_PROTO(unsigned int ipi_nr),
+
+       TP_ARGS(ipi_nr)
+);
+
+/**
+ * arm_ipi_exit - called in the arm-generic ipi handler immediately
+ *                after the ipi-type handler returns
+ * @ipi_nr:  ipi number
+ *
+ * When used in combination with the arm_ipi_entry tracepoint
+ * we can determine the ipi handler runtine.
+ */
+DEFINE_EVENT(arm_ipi, arm_ipi_exit,
+
+       TP_PROTO(unsigned int ipi_nr),
+
+       TP_ARGS(ipi_nr)
+);
+
+/**
+ * arm_ipi_send - called as the ipi target mask is built, immediately
+ *                before the register is written
+ * @ipi_nr:  ipi number
+ * @dest:    cpu to send to
+ *
+ * When used in combination with the arm_ipi_entry tracepoint
+ * we can determine the ipi raise to run latency.
+ */
+TRACE_EVENT(arm_ipi_send,
+
+       TP_PROTO(unsigned int ipi_nr, int dest),
+
+       TP_ARGS(ipi_nr, dest),
+
+       TP_STRUCT__entry(
+               __field(        unsigned int,   ipi     )
+               __field(        int                     ,       dest )
+       ),
+
+       TP_fast_assign(
+               __entry->ipi = ipi_nr;
+               __entry->dest = dest;
+       ),
+
+       TP_printk("dest=%d ipi=%u [action=%s]", __entry->dest,
+                       __entry->ipi, show_arm_ipi_name(__entry->ipi))
+);
+
+#endif /*  _TRACE_ARM_IPI_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>