MIPS: Add hook to get C0 performance counter interrupt
The hardware perf event driver and oprofile interpret the global
cp0_perfcount_irq differently: in the hardware perf event driver
it is an offset from MIPS_CPU_IRQ_BASE and in oprofile it is the
actual IRQ number. This still works most of the time since
MIPS_CPU_IRQ_BASE is usually 0, but is clearly wrong. Since the
performance counter interrupt may vary from platform to platform
like the C0 timer interrupt, add the optional get_c0_perfcount_int
hook which returns the IRQ number of the performance counter.
The hook should return < 0 if the performance counter interrupt is
shared with the timer. If the hook is not present, the CPU vector
reported in C0_IntCtl (cp0_perfcount_irq) is used.
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Reviewed-by: Qais Yousef <qais.yousef@imgtec.com>
Tested-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Jeffrey Deans <jeffrey.deans@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: John Crispin <blogic@openwrt.org>
Cc: David Daney <ddaney.cavm@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7805/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/oprofile/op_model_mipsxx.c b/arch/mips/oprofile/op_model_mipsxx.c
index 42821ae..01f721a 100644
--- a/arch/mips/oprofile/op_model_mipsxx.c
+++ b/arch/mips/oprofile/op_model_mipsxx.c
@@ -11,6 +11,7 @@
#include <linux/interrupt.h>
#include <linux/smp.h>
#include <asm/irq_regs.h>
+#include <asm/time.h>
#include "op_impl.h"
@@ -35,6 +36,7 @@
#define M_PERFCTL_COUNT_ALL_THREADS (1UL << 13)
static int (*save_perf_irq)(void);
+static int perfcount_irq;
/*
* XLR has only one set of counters per core. Designate the
@@ -431,8 +433,16 @@
save_perf_irq = perf_irq;
perf_irq = mipsxx_perfcount_handler;
- if ((cp0_perfcount_irq >= 0) && (cp0_compare_irq != cp0_perfcount_irq))
- return request_irq(cp0_perfcount_irq, mipsxx_perfcount_int,
+ if (get_c0_perfcount_int)
+ perfcount_irq = get_c0_perfcount_int();
+ else if ((cp0_perfcount_irq >= 0) &&
+ (cp0_compare_irq != cp0_perfcount_irq))
+ perfcount_irq = MIPS_CPU_IRQ_BASE + cp0_perfcount_irq;
+ else
+ perfcount_irq = -1;
+
+ if (perfcount_irq >= 0)
+ return request_irq(perfcount_irq, mipsxx_perfcount_int,
0, "Perfcounter", save_perf_irq);
return 0;
@@ -442,8 +452,8 @@
{
int counters = op_model_mipsxx_ops.num_counters;
- if ((cp0_perfcount_irq >= 0) && (cp0_compare_irq != cp0_perfcount_irq))
- free_irq(cp0_perfcount_irq, save_perf_irq);
+ if (perfcount_irq >= 0)
+ free_irq(perfcount_irq, save_perf_irq);
counters = counters_per_cpu_to_total(counters);
on_each_cpu(reset_counters, (void *)(long)counters, 1);