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Unverified Commit 8b20d2db authored by Anup Patel's avatar Anup Patel Committed by Palmer Dabbelt
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RISC-V: Show IPI stats 



This patch provides arch_show_interrupts() implementation to
show IPI stats via /proc/interrupts.

Now the contents of /proc/interrupts" will look like below:
           CPU0       CPU1       CPU2       CPU3
  8:         17          7          6         14  SiFive PLIC   8  virtio0
 10:         10         10          9         11  SiFive PLIC  10  ttyS0
IPI0:       170        673        251         79  Rescheduling interrupts
IPI1:         1         12         27          1  Function call interrupts

Signed-off-by: default avatarAnup Patel <anup@brainfault.org>
[Atish - Fixed checkpatch errors]
Signed-off-by: default avatarAtish Patra <atish.patra@wdc.com>
Reviewed-by: default avatarPalmer Dabbelt <palmer@sifive.com>

Changes since v2:
 - Remove use of IPI_CALL_WAKEUP because it's being removed

Changes since v1:
 - Add stub inline show_ipi_stats() function for !CONFIG_SMP
 - Make ipi_names[] dynamically sized at compile time
 - Minor beautification of ipi_names[] using tabs

Signed-off-by: default avatarPalmer Dabbelt <palmer@sifive.com>
parent 4b26d22f

arch/riscv/include/asm/smp.h

+9 −0
Original line number Diff line number Diff line
@@ -25,8 +25,13 @@ 
extern unsigned long __cpuid_to_hartid_map[NR_CPUS];

#define cpuid_to_hartid_map(cpu)    __cpuid_to_hartid_map[cpu]



struct seq_file;



#ifdef CONFIG_SMP



/* print IPI stats */

void show_ipi_stats(struct seq_file *p, int prec);



/* SMP initialization hook for setup_arch */

void __init setup_smp(void);
@@ -47,6 +52,10 @@ void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out); 


#else



static inline void show_ipi_stats(struct seq_file *p, int prec)

{

}



static inline int riscv_hartid_to_cpuid(int hartid)

{

	return 0;

arch/riscv/kernel/irq.c

+8 −0
Original line number Diff line number Diff line
@@ -8,6 +8,8 @@ 
#include <linux/interrupt.h>

#include <linux/irqchip.h>

#include <linux/irqdomain.h>

#include <linux/seq_file.h>

#include <asm/smp.h>



/*

 * Possible interrupt causes:
@@ -24,6 +26,12 @@ 
 */

#define INTERRUPT_CAUSE_FLAG	(1UL << (__riscv_xlen - 1))



int arch_show_interrupts(struct seq_file *p, int prec)

{

	show_ipi_stats(p, prec);

	return 0;

}



asmlinkage void __irq_entry do_IRQ(struct pt_regs *regs)

{

	struct pt_regs *old_regs = set_irq_regs(regs);

arch/riscv/kernel/smp.c

+32 −7
Original line number Diff line number Diff line
@@ -22,22 +22,24 @@ 
#include <linux/interrupt.h>

#include <linux/smp.h>

#include <linux/sched.h>

#include <linux/seq_file.h>



#include <asm/sbi.h>

#include <asm/tlbflush.h>

#include <asm/cacheflush.h>



/* A collection of single bit ipi messages.  */

static struct {

	unsigned long bits ____cacheline_aligned;

} ipi_data[NR_CPUS] __cacheline_aligned;



enum ipi_message_type {

	IPI_RESCHEDULE,

	IPI_CALL_FUNC,

	IPI_MAX

};



/* A collection of single bit ipi messages.  */

static struct {

	unsigned long stats[IPI_MAX] ____cacheline_aligned;

	unsigned long bits ____cacheline_aligned;

} ipi_data[NR_CPUS] __cacheline_aligned;



int riscv_hartid_to_cpuid(int hartid)

{

	int i = -1;
@@ -67,6 +69,7 @@ int setup_profiling_timer(unsigned int multiplier) 
void riscv_software_interrupt(void)

{

	unsigned long *pending_ipis = &ipi_data[smp_processor_id()].bits;

	unsigned long *stats = ipi_data[smp_processor_id()].stats;



	/* Clear pending IPI */

	csr_clear(sip, SIE_SSIE);
@@ -81,11 +84,15 @@ void riscv_software_interrupt(void) 
		if (ops == 0)

			return;



		if (ops & (1 << IPI_RESCHEDULE))

		if (ops & (1 << IPI_RESCHEDULE)) {

			stats[IPI_RESCHEDULE]++;

			scheduler_ipi();

		}



		if (ops & (1 << IPI_CALL_FUNC))

		if (ops & (1 << IPI_CALL_FUNC)) {

			stats[IPI_CALL_FUNC]++;

			generic_smp_call_function_interrupt();

		}



		BUG_ON((ops >> IPI_MAX) != 0);
@@ -111,6 +118,24 @@ send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation) 
	sbi_send_ipi(cpumask_bits(&hartid_mask));

}



static const char * const ipi_names[] = {

	[IPI_RESCHEDULE]	= "Rescheduling interrupts",

	[IPI_CALL_FUNC]		= "Function call interrupts",

};



void show_ipi_stats(struct seq_file *p, int prec)

{

	unsigned int cpu, i;



	for (i = 0; i < IPI_MAX; i++) {

		seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,

			   prec >= 4 ? " " : "");

		for_each_online_cpu(cpu)

			seq_printf(p, "%10lu ", ipi_data[cpu].stats[i]);

		seq_printf(p, " %s\n", ipi_names[i]);

	}

}



void arch_send_call_function_ipi_mask(struct cpumask *mask)

{

	send_ipi_message(mask, IPI_CALL_FUNC);