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-rw-r--r--kernel/irq/timings.c119
1 files changed, 119 insertions, 0 deletions
diff --git a/kernel/irq/timings.c b/kernel/irq/timings.c
index bc04eca6ef84..95b63bdea156 100644
--- a/kernel/irq/timings.c
+++ b/kernel/irq/timings.c
@@ -1,10 +1,12 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2016, Linaro Ltd - Daniel Lezcano <daniel.lezcano@linaro.org>
+#define pr_fmt(fmt) "irq_timings: " fmt
#include <linux/kernel.h>
#include <linux/percpu.h>
#include <linux/slab.h>
#include <linux/static_key.h>
+#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/idr.h>
#include <linux/irq.h>
@@ -625,3 +627,120 @@ int irq_timings_alloc(int irq)
return 0;
}
+
+#ifdef CONFIG_TEST_IRQ_TIMINGS
+static int __init irq_timings_test_irqts(struct irq_timings *irqts,
+ unsigned count)
+{
+ int start = count >= IRQ_TIMINGS_SIZE ? count - IRQ_TIMINGS_SIZE : 0;
+ int i, irq, oirq = 0xBEEF;
+ u64 ots = 0xDEAD, ts;
+
+ /*
+ * Fill the circular buffer by using the dedicated function.
+ */
+ for (i = 0; i < count; i++) {
+ pr_debug("%d: index=%d, ts=%llX irq=%X\n",
+ i, i & IRQ_TIMINGS_MASK, ots + i, oirq + i);
+
+ irq_timings_push(ots + i, oirq + i);
+ }
+
+ /*
+ * Compute the first elements values after the index wrapped
+ * up or not.
+ */
+ ots += start;
+ oirq += start;
+
+ /*
+ * Test the circular buffer count is correct.
+ */
+ pr_debug("---> Checking timings array count (%d) is right\n", count);
+ if (WARN_ON(irqts->count != count))
+ return -EINVAL;
+
+ /*
+ * Test the macro allowing to browse all the irqts.
+ */
+ pr_debug("---> Checking the for_each_irqts() macro\n");
+ for_each_irqts(i, irqts) {
+
+ irq = irq_timing_decode(irqts->values[i], &ts);
+
+ pr_debug("index=%d, ts=%llX / %llX, irq=%X / %X\n",
+ i, ts, ots, irq, oirq);
+
+ if (WARN_ON(ts != ots || irq != oirq))
+ return -EINVAL;
+
+ ots++; oirq++;
+ }
+
+ /*
+ * The circular buffer should have be flushed when browsed
+ * with for_each_irqts
+ */
+ pr_debug("---> Checking timings array is empty after browsing it\n");
+ if (WARN_ON(irqts->count))
+ return -EINVAL;
+
+ return 0;
+}
+
+static int __init irq_timings_irqts_selftest(void)
+{
+ struct irq_timings *irqts = this_cpu_ptr(&irq_timings);
+ int i, ret;
+
+ /*
+ * Test the circular buffer with different number of
+ * elements. The purpose is to test at the limits (empty, half
+ * full, full, wrapped with the cursor at the boundaries,
+ * wrapped several times, etc ...
+ */
+ int count[] = { 0,
+ IRQ_TIMINGS_SIZE >> 1,
+ IRQ_TIMINGS_SIZE,
+ IRQ_TIMINGS_SIZE + (IRQ_TIMINGS_SIZE >> 1),
+ 2 * IRQ_TIMINGS_SIZE,
+ (2 * IRQ_TIMINGS_SIZE) + 3,
+ };
+
+ for (i = 0; i < ARRAY_SIZE(count); i++) {
+
+ pr_info("---> Checking the timings with %d/%d values\n",
+ count[i], IRQ_TIMINGS_SIZE);
+
+ ret = irq_timings_test_irqts(irqts, count[i]);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
+static int __init irq_timings_selftest(void)
+{
+ int ret;
+
+ pr_info("------------------- selftest start -----------------\n");
+
+ /*
+ * At this point, we don't except any subsystem to use the irq
+ * timings but us, so it should not be enabled.
+ */
+ if (static_branch_unlikely(&irq_timing_enabled)) {
+ pr_warn("irq timings already initialized, skipping selftest\n");
+ return 0;
+ }
+
+ ret = irq_timings_irqts_selftest();
+
+ pr_info("---------- selftest end with %s -----------\n",
+ ret ? "failure" : "success");
+
+ return ret;
+}
+early_initcall(irq_timings_selftest);
+#endif