[PATCH v2 1/4] ARC: perf: trivial code cleanup

From: Eugeniy Paltsev
Date: Thu Dec 13 2018 - 11:56:38 EST


* Use BIT(), lower_32_bits(), upper_32_bits() macroses,
fix code style violations.
* Use u32, u64, s64 instead of uint32_t, uint64_t, int64_t
* Fix description comment as this code doesn't belong only to
ARC700 anymore.
* Use SPDX License Identifier.
* Remove useless ifdefs. ifdef around 'arc_pmu_match' structure
declaration is useless as we refer to 'arc_pmu_match' in
several places which aren't guarded with ifdef. Nevertheless
'ARC' option selects 'OF' unconditionally so we can simply
get rid of this ifdef.

Acked-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx>
---
Changes v1->v2:
* Squash first four cleanup patches into this one.

arch/arc/kernel/perf_event.c | 85 ++++++++++++++++++++++----------------------
1 file changed, 42 insertions(+), 43 deletions(-)

diff --git a/arch/arc/kernel/perf_event.c b/arch/arc/kernel/perf_event.c
index 8aec462d90fb..693f32d60c35 100644
--- a/arch/arc/kernel/perf_event.c
+++ b/arch/arc/kernel/perf_event.c
@@ -1,15 +1,10 @@
-/*
- * Linux performance counter support for ARC700 series
- *
- * Copyright (C) 2013-2015 Synopsys, Inc. (www.synopsys.com)
- *
- * This code is inspired by the perf support of various other architectures.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- */
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Linux performance counter support for ARC CPUs.
+// This code is inspired by the perf support of various other architectures.
+//
+// Copyright (C) 2013-2018 Synopsys, Inc. (www.synopsys.com)
+
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/module.h>
@@ -19,6 +14,9 @@
#include <asm/arcregs.h>
#include <asm/stacktrace.h>

+/* HW holds 8 symbols + one for null terminator */
+#define ARCPMU_EVENT_NAME_LEN 9
+
struct arc_pmu {
struct pmu pmu;
unsigned int irq;
@@ -49,6 +47,7 @@ static int callchain_trace(unsigned int addr, void *data)
{
struct arc_callchain_trace *ctrl = data;
struct perf_callchain_entry_ctx *entry = ctrl->perf_stuff;
+
perf_callchain_store(entry, addr);

if (ctrl->depth++ < 3)
@@ -57,8 +56,8 @@ static int callchain_trace(unsigned int addr, void *data)
return -1;
}

-void
-perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
+void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
+ struct pt_regs *regs)
{
struct arc_callchain_trace ctrl = {
.depth = 0,
@@ -68,8 +67,8 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
arc_unwind_core(NULL, regs, callchain_trace, &ctrl);
}

-void
-perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
+void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
+ struct pt_regs *regs)
{
/*
* User stack can't be unwound trivially with kernel dwarf unwinder
@@ -82,10 +81,10 @@ static struct arc_pmu *arc_pmu;
static DEFINE_PER_CPU(struct arc_pmu_cpu, arc_pmu_cpu);

/* read counter #idx; note that counter# != event# on ARC! */
-static uint64_t arc_pmu_read_counter(int idx)
+static u64 arc_pmu_read_counter(int idx)
{
- uint32_t tmp;
- uint64_t result;
+ u32 tmp;
+ u64 result;

/*
* ARC supports making 'snapshots' of the counters, so we don't
@@ -94,7 +93,7 @@ static uint64_t arc_pmu_read_counter(int idx)
write_aux_reg(ARC_REG_PCT_INDEX, idx);
tmp = read_aux_reg(ARC_REG_PCT_CONTROL);
write_aux_reg(ARC_REG_PCT_CONTROL, tmp | ARC_REG_PCT_CONTROL_SN);
- result = (uint64_t) (read_aux_reg(ARC_REG_PCT_SNAPH)) << 32;
+ result = (u64) (read_aux_reg(ARC_REG_PCT_SNAPH)) << 32;
result |= read_aux_reg(ARC_REG_PCT_SNAPL);

return result;
@@ -103,9 +102,9 @@ static uint64_t arc_pmu_read_counter(int idx)
static void arc_perf_event_update(struct perf_event *event,
struct hw_perf_event *hwc, int idx)
{
- uint64_t prev_raw_count = local64_read(&hwc->prev_count);
- uint64_t new_raw_count = arc_pmu_read_counter(idx);
- int64_t delta = new_raw_count - prev_raw_count;
+ u64 prev_raw_count = local64_read(&hwc->prev_count);
+ u64 new_raw_count = arc_pmu_read_counter(idx);
+ s64 delta = new_raw_count - prev_raw_count;

/*
* We aren't afraid of hwc->prev_count changing beneath our feet
@@ -155,7 +154,7 @@ static int arc_pmu_event_init(struct perf_event *event)
int ret;

if (!is_sampling_event(event)) {
- hwc->sample_period = arc_pmu->max_period;
+ hwc->sample_period = arc_pmu->max_period;
hwc->last_period = hwc->sample_period;
local64_set(&hwc->period_left, hwc->sample_period);
}
@@ -192,6 +191,7 @@ static int arc_pmu_event_init(struct perf_event *event)
pr_debug("init cache event with h/w %08x \'%s\'\n",
(int)hwc->config, arc_pmu_ev_hw_map[ret]);
return 0;
+
default:
return -ENOENT;
}
@@ -200,7 +200,7 @@ static int arc_pmu_event_init(struct perf_event *event)
/* starts all counters */
static void arc_pmu_enable(struct pmu *pmu)
{
- uint32_t tmp;
+ u32 tmp;
tmp = read_aux_reg(ARC_REG_PCT_CONTROL);
write_aux_reg(ARC_REG_PCT_CONTROL, (tmp & 0xffff0000) | 0x1);
}
@@ -208,7 +208,7 @@ static void arc_pmu_enable(struct pmu *pmu)
/* stops all counters */
static void arc_pmu_disable(struct pmu *pmu)
{
- uint32_t tmp;
+ u32 tmp;
tmp = read_aux_reg(ARC_REG_PCT_CONTROL);
write_aux_reg(ARC_REG_PCT_CONTROL, (tmp & 0xffff0000) | 0x0);
}
@@ -228,7 +228,7 @@ static int arc_pmu_event_set_period(struct perf_event *event)
local64_set(&hwc->period_left, left);
hwc->last_period = period;
overflow = 1;
- } else if (unlikely(left <= 0)) {
+ } else if (unlikely(left <= 0)) {
/* left underflowed by less than period. */
left += period;
local64_set(&hwc->period_left, left);
@@ -246,8 +246,8 @@ static int arc_pmu_event_set_period(struct perf_event *event)
write_aux_reg(ARC_REG_PCT_INDEX, idx);

/* Write value */
- write_aux_reg(ARC_REG_PCT_COUNTL, (u32)value);
- write_aux_reg(ARC_REG_PCT_COUNTH, (value >> 32));
+ write_aux_reg(ARC_REG_PCT_COUNTL, lower_32_bits(value));
+ write_aux_reg(ARC_REG_PCT_COUNTH, upper_32_bits(value));

perf_event_update_userpage(event);

@@ -277,7 +277,7 @@ static void arc_pmu_start(struct perf_event *event, int flags)
/* Enable interrupt for this counter */
if (is_sampling_event(event))
write_aux_reg(ARC_REG_PCT_INT_CTRL,
- read_aux_reg(ARC_REG_PCT_INT_CTRL) | (1 << idx));
+ read_aux_reg(ARC_REG_PCT_INT_CTRL) | BIT(idx));

/* enable ARC pmu here */
write_aux_reg(ARC_REG_PCT_INDEX, idx); /* counter # */
@@ -295,9 +295,9 @@ static void arc_pmu_stop(struct perf_event *event, int flags)
* Reset interrupt flag by writing of 1. This is required
* to make sure pending interrupt was not left.
*/
- write_aux_reg(ARC_REG_PCT_INT_ACT, 1 << idx);
+ write_aux_reg(ARC_REG_PCT_INT_ACT, BIT(idx));
write_aux_reg(ARC_REG_PCT_INT_CTRL,
- read_aux_reg(ARC_REG_PCT_INT_CTRL) & ~(1 << idx));
+ read_aux_reg(ARC_REG_PCT_INT_CTRL) & ~BIT(idx));
}

if (!(event->hw.state & PERF_HES_STOPPED)) {
@@ -349,9 +349,10 @@ static int arc_pmu_add(struct perf_event *event, int flags)

if (is_sampling_event(event)) {
/* Mimic full counter overflow as other arches do */
- write_aux_reg(ARC_REG_PCT_INT_CNTL, (u32)arc_pmu->max_period);
+ write_aux_reg(ARC_REG_PCT_INT_CNTL,
+ lower_32_bits(arc_pmu->max_period));
write_aux_reg(ARC_REG_PCT_INT_CNTH,
- (arc_pmu->max_period >> 32));
+ upper_32_bits(arc_pmu->max_period));
}

write_aux_reg(ARC_REG_PCT_CONFIG, 0);
@@ -392,7 +393,7 @@ static irqreturn_t arc_pmu_intr(int irq, void *dev)
idx = __ffs(active_ints);

/* Reset interrupt flag by writing of 1 */
- write_aux_reg(ARC_REG_PCT_INT_ACT, 1 << idx);
+ write_aux_reg(ARC_REG_PCT_INT_ACT, BIT(idx));

/*
* On reset of "interrupt active" bit corresponding
@@ -400,7 +401,7 @@ static irqreturn_t arc_pmu_intr(int irq, void *dev)
* Now we need to re-enable interrupt for the counter.
*/
write_aux_reg(ARC_REG_PCT_INT_CTRL,
- read_aux_reg(ARC_REG_PCT_INT_CTRL) | (1 << idx));
+ read_aux_reg(ARC_REG_PCT_INT_CTRL) | BIT(idx));

event = pmu_cpu->act_counter[idx];
hwc = &event->hw;
@@ -414,7 +415,7 @@ static irqreturn_t arc_pmu_intr(int irq, void *dev)
arc_pmu_stop(event, 0);
}

- active_ints &= ~(1U << idx);
+ active_ints &= ~BIT(idx);
} while (active_ints);

done:
@@ -450,10 +451,10 @@ static int arc_pmu_device_probe(struct platform_device *pdev)

union cc_name {
struct {
- uint32_t word0, word1;
+ u32 word0, word1;
char sentinel;
} indiv;
- char str[9];
+ char str[ARCPMU_EVENT_NAME_LEN];
} cc_name;


@@ -481,9 +482,9 @@ static int arc_pmu_device_probe(struct platform_device *pdev)

pr_info("ARC perf\t: %d counters (%d bits), %d conditions%s\n",
arc_pmu->n_counters, counter_size, cc_bcr.c,
- has_interrupts ? ", [overflow IRQ support]":"");
+ has_interrupts ? ", [overflow IRQ support]" : "");

- cc_name.str[8] = 0;
+ cc_name.str[ARCPMU_EVENT_NAME_LEN - 1] = 0;
for (i = 0; i < PERF_COUNT_ARC_HW_MAX; i++)
arc_pmu->ev_hw_idx[i] = -1;

@@ -538,14 +539,12 @@ static int arc_pmu_device_probe(struct platform_device *pdev)
return perf_pmu_register(&arc_pmu->pmu, pdev->name, PERF_TYPE_RAW);
}

-#ifdef CONFIG_OF
static const struct of_device_id arc_pmu_match[] = {
{ .compatible = "snps,arc700-pct" },
{ .compatible = "snps,archs-pct" },
{},
};
MODULE_DEVICE_TABLE(of, arc_pmu_match);
-#endif

static struct platform_driver arc_pmu_driver = {
.driver = {
--
2.14.5