treewide: Trace IPIs sent via smp_send_reschedule()

To be able to trace invocations of smp_send_reschedule(), rename the
arch-specific definitions of it to arch_smp_send_reschedule() and wrap it
into an smp_send_reschedule() that contains a tracepoint.

Changes to include the declaration of the tracepoint were driven by the
following coccinelle script:

@func_use@
@@
smp_send_reschedule(...);

@include@
@@
#include <trace/events/ipi.h>

@no_include depends on func_use && !include@
@@
#include <...>
+
+ #include <trace/events/ipi.h>

[csky bits]
[riscv bits]
Signed-off-by: Valentin Schneider <[e-mail]>
Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Acked-by: Guo Ren <[e-mail]>
Acked-by: Palmer Dabbelt <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/alpha/kernel/smp.c

···
 }
 
 void
-smp_send_reschedule(int cpu)
+arch_smp_send_reschedule(int cpu)
 {
 #ifdef DEBUG_IPI_MSG
 	if (cpu == hard_smp_processor_id())

arch/arc/kernel/smp.c

···
 		ipi_send_msg_one(cpu, msg);
 }
 
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	ipi_send_msg_one(cpu, IPI_RESCHEDULE);
 }

arch/arm/kernel/smp.c

···
 	ipi_setup(smp_processor_id());
 }
 
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
 }

arch/arm/mach-actions/platsmp.c

···
 #include <asm/smp_plat.h>
 #include <asm/smp_scu.h>
 
+#include <trace/events/ipi.h>
+
 #define OWL_CPU1_ADDR	0x50
 #define OWL_CPU1_FLAG	0x5c
 

arch/arm64/kernel/smp.c

···
 	ipi_setup(smp_processor_id());
 }
 
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
 }

arch/csky/kernel/smp.c

···
 	on_each_cpu(ipi_stop, NULL, 1);
 }
 
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
 }

arch/hexagon/kernel/smp.c

···
 	}
 }
 
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	send_ipi(cpumask_of(cpu), IPI_RESCHEDULE);
 }

arch/ia64/kernel/smp.c

···
  * Called with preemption disabled.
  */
 void
-smp_send_reschedule (int cpu)
+arch_smp_send_reschedule (int cpu)
 {
 	ia64_send_ipi(cpu, IA64_IPI_RESCHEDULE, IA64_IPI_DM_INT, 0);
 }
-EXPORT_SYMBOL_GPL(smp_send_reschedule);
+EXPORT_SYMBOL_GPL(arch_smp_send_reschedule);
 
 /*
  * Called with preemption disabled.

arch/loongarch/kernel/smp.c

···
  * it goes straight through and wastes no time serializing
  * anything. Worst case is that we lose a reschedule ...
  */
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	loongson_send_ipi_single(cpu, SMP_RESCHEDULE);
 }
-EXPORT_SYMBOL_GPL(smp_send_reschedule);
+EXPORT_SYMBOL_GPL(arch_smp_send_reschedule);
 
 irqreturn_t loongson_ipi_interrupt(int irq, void *dev)
 {

arch/mips/include/asm/smp.h

···
  * it goes straight through and wastes no time serializing
  * anything. Worst case is that we lose a reschedule ...
  */
-static inline void smp_send_reschedule(int cpu)
+static inline void arch_smp_send_reschedule(int cpu)
 {
 	extern const struct plat_smp_ops *mp_ops;	/* private */
 

arch/mips/kernel/rtlx-cmp.c

···
 #include <asm/vpe.h>
 #include <asm/rtlx.h>
 
+#include <trace/events/ipi.h>
+
 static int major;
 
 static void rtlx_interrupt(void)

arch/openrisc/kernel/smp.c

···
 	}
 }
 
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
 }

arch/parisc/kernel/smp.c

···
 inline void 
 smp_send_stop(void)	{ send_IPI_allbutself(IPI_CPU_STOP); }
 
-void 
-smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
+void
+arch_smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
 
 void
 smp_send_all_nop(void)

arch/powerpc/kernel/smp.c

···
 #include <asm/kup.h>
 #include <asm/fadump.h>
 
+#include <trace/events/ipi.h>
+
 #ifdef DEBUG
 #include <asm/udbg.h>
 #define DBG(fmt...) udbg_printf(fmt)
···
 #endif
 }
 
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	if (likely(smp_ops))
 		do_message_pass(cpu, PPC_MSG_RESCHEDULE);
 }
-EXPORT_SYMBOL_GPL(smp_send_reschedule);
+EXPORT_SYMBOL_GPL(arch_smp_send_reschedule);
 
 void arch_send_call_function_single_ipi(int cpu)
 {

arch/powerpc/kvm/book3s_hv.c

···
 #include <linux/compiler.h>
 #include <linux/of.h>
 #include <linux/irqdomain.h>
+#include <linux/smp.h>
 
 #include <asm/ftrace.h>
 #include <asm/reg.h>
···
 #include <asm/ultravisor.h>
 #include <asm/dtl.h>
 #include <asm/plpar_wrappers.h>
+
+#include <trace/events/ipi.h>
 
 #include "book3s.h"
 #include "book3s_hv.h"

arch/powerpc/platforms/powernv/subcore.c

···
 #include <asm/opal.h>
 #include <asm/smp.h>
 
+#include <trace/events/ipi.h>
+
 #include "subcore.h"
 #include "powernv.h"
 

arch/riscv/kernel/smp.c

···
 }
 #endif
 
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	send_ipi_single(cpu, IPI_RESCHEDULE);
 }
-EXPORT_SYMBOL_GPL(smp_send_reschedule);
+EXPORT_SYMBOL_GPL(arch_smp_send_reschedule);

arch/s390/kernel/smp.c

···
  * it goes straight through and wastes no time serializing
  * anything. Worst case is that we lose a reschedule ...
  */
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
 }

arch/sh/kernel/smp.c

···
 	       (bogosum / (5000/HZ)) % 100);
 }
 
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
 }

arch/sparc/kernel/smp_32.c

···
 
 struct linux_prom_registers smp_penguin_ctable = { 0 };
 
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	/*
 	 * CPU model dependent way of implementing IPI generation targeting

arch/sparc/kernel/smp_64.c

···
 	return hv_err;
 }
 
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	if (cpu == smp_processor_id()) {
 		WARN_ON_ONCE(preemptible());

arch/x86/include/asm/smp.h

···
 	smp_ops.play_dead();
 }
 
-static inline void smp_send_reschedule(int cpu)
+static inline void arch_smp_send_reschedule(int cpu)
 {
 	smp_ops.smp_send_reschedule(cpu);
 }

arch/x86/kvm/svm/svm.c

···
 #include <linux/swap.h>
 #include <linux/rwsem.h>
 #include <linux/cc_platform.h>
+#include <linux/smp.h>
 
 #include <asm/apic.h>
 #include <asm/perf_event.h>
···
 #include <asm/fpu/api.h>
 
 #include <asm/virtext.h>
+
+#include <trace/events/ipi.h>
+
 #include "trace.h"
 
 #include "svm.h"

arch/x86/kvm/x86.c

···
 #include <linux/mem_encrypt.h>
 #include <linux/entry-kvm.h>
 #include <linux/suspend.h>
+#include <linux/smp.h>
 
+#include <trace/events/ipi.h>
 #include <trace/events/kvm.h>
 
 #include <asm/debugreg.h>

arch/xtensa/kernel/smp.c

···
 	send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC);
 }
 
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
 {
 	send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
 }

include/linux/smp.h

···
 /*
  * sends a 'reschedule' event to another CPU:
  */
-extern void smp_send_reschedule(int cpu);
-
+extern void arch_smp_send_reschedule(int cpu);
+/*
+ * scheduler_ipi() is inline so can't be passed as callback reason, but the
+ * callsite IP should be sufficient for root-causing IPIs sent from here.
+ */
+#define smp_send_reschedule(cpu) ({				  \
+	trace_ipi_send_cpumask(cpumask_of(cpu), _RET_IP_, NULL);  \
+	arch_smp_send_reschedule(cpu);				  \
+})
 
 /*
  * Prepare machine for booting other CPUs.

virt/kvm/kvm_main.c

···
 #include "kvm_mm.h"
 #include "vfio.h"
 
+#include <trace/events/ipi.h>
+
 #define CREATE_TRACE_POINTS
 #include <trace/events/kvm.h>
 
 #include <linux/kvm_dirty_ring.h>
+
 
 /* Worst case buffer size needed for holding an integer. */
 #define ITOA_MAX_LEN 12