diff options
Diffstat (limited to 'kernel/irq/timings.c')
| -rw-r--r-- | kernel/irq/timings.c | 119 |
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 |