diff options
Diffstat (limited to 'drivers/gator/gator_events_irq.c')
-rw-r--r-- | drivers/gator/gator_events_irq.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/drivers/gator/gator_events_irq.c b/drivers/gator/gator_events_irq.c new file mode 100644 index 00000000000..435bc86fb5d --- /dev/null +++ b/drivers/gator/gator_events_irq.c @@ -0,0 +1,188 @@ +/** + * Copyright (C) ARM Limited 2010-2012. All rights reserved. + * + * 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. + * + */ + +#include "gator.h" +#include <trace/events/irq.h> + +#define HARDIRQ 0 +#define SOFTIRQ 1 +#define TOTALIRQ (SOFTIRQ+1) + +static ulong hardirq_enabled; +static ulong softirq_enabled; +static ulong hardirq_key; +static ulong softirq_key; +static DEFINE_PER_CPU(int[TOTALIRQ], irqCnt); +static DEFINE_PER_CPU(int[TOTALIRQ * 2], irqGet); + +GATOR_DEFINE_PROBE(irq_handler_exit, TP_PROTO(int irq, + struct irqaction *action, int ret)) +{ + unsigned long flags; + + // disable interrupts to synchronize with gator_events_irq_read() + // spinlocks not needed since percpu buffers are used + local_irq_save(flags); + per_cpu(irqCnt, smp_processor_id())[HARDIRQ]++; + local_irq_restore(flags); +} + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 37) +GATOR_DEFINE_PROBE(softirq_exit, TP_PROTO(struct softirq_action *h, struct softirq_action *vec)) +#else +GATOR_DEFINE_PROBE(softirq_exit, TP_PROTO(unsigned int vec_nr)) +#endif +{ + unsigned long flags; + + // disable interrupts to synchronize with gator_events_irq_read() + // spinlocks not needed since percpu buffers are used + local_irq_save(flags); + per_cpu(irqCnt, smp_processor_id())[SOFTIRQ]++; + local_irq_restore(flags); +} + +static int gator_events_irq_create_files(struct super_block *sb, struct dentry *root) +{ + struct dentry *dir; + + /* irq */ + dir = gatorfs_mkdir(sb, root, "Linux_irq_irq"); + if (!dir) { + return -1; + } + gatorfs_create_ulong(sb, dir, "enabled", &hardirq_enabled); + gatorfs_create_ro_ulong(sb, dir, "key", &hardirq_key); + + /* soft irq */ + dir = gatorfs_mkdir(sb, root, "Linux_irq_softirq"); + if (!dir) { + return -1; + } + gatorfs_create_ulong(sb, dir, "enabled", &softirq_enabled); + gatorfs_create_ro_ulong(sb, dir, "key", &softirq_key); + + return 0; +} + +static int gator_events_irq_online(int** buffer) +{ + int len = 0, cpu = smp_processor_id(); + unsigned long flags; // not necessary as we are in interrupt context anyway, but doesn't hurt + + // synchronization with the irq_exit functions is not necessary as the values are being reset + if (hardirq_enabled) { + local_irq_save(flags); + per_cpu(irqCnt, cpu)[HARDIRQ] = 0; + local_irq_restore(flags); + per_cpu(irqGet, cpu)[len++] = hardirq_key; + per_cpu(irqGet, cpu)[len++] = 0; + } + + if (softirq_enabled) { + local_irq_save(flags); + per_cpu(irqCnt, cpu)[SOFTIRQ] = 0; + local_irq_restore(flags); + per_cpu(irqGet, cpu)[len++] = softirq_key; + per_cpu(irqGet, cpu)[len++] = 0; + } + + if (buffer) + *buffer = per_cpu(irqGet, cpu); + + return len; +} + +static int gator_events_irq_start(void) +{ + // register tracepoints + if (hardirq_enabled) + if (GATOR_REGISTER_TRACE(irq_handler_exit)) + goto fail_hardirq_exit; + if (softirq_enabled) + if (GATOR_REGISTER_TRACE(softirq_exit)) + goto fail_softirq_exit; + pr_debug("gator: registered irq tracepoints\n"); + + return 0; + + // unregister tracepoints on error +fail_softirq_exit: + if (hardirq_enabled) + GATOR_UNREGISTER_TRACE(irq_handler_exit); +fail_hardirq_exit: + pr_err("gator: irq tracepoints failed to activate, please verify that tracepoints are enabled in the linux kernel\n"); + + return -1; +} + +static void gator_events_irq_stop(void) +{ + if (hardirq_enabled) + GATOR_UNREGISTER_TRACE(irq_handler_exit); + if (softirq_enabled) + GATOR_UNREGISTER_TRACE(softirq_exit); + pr_debug("gator: unregistered irq tracepoints\n"); + + hardirq_enabled = 0; + softirq_enabled = 0; +} + +static int gator_events_irq_read(int **buffer) +{ + unsigned long flags; // not necessary as we are in interrupt context anyway, but doesn't hurt + int len, value; + int cpu = smp_processor_id(); + + len = 0; + if (hardirq_enabled) { + local_irq_save(flags); + value = per_cpu(irqCnt, cpu)[HARDIRQ]; + per_cpu(irqCnt, cpu)[HARDIRQ] = 0; + local_irq_restore(flags); + + per_cpu(irqGet, cpu)[len++] = hardirq_key; + per_cpu(irqGet, cpu)[len++] = value; + } + + if (softirq_enabled) { + local_irq_save(flags); + value = per_cpu(irqCnt, cpu)[SOFTIRQ]; + per_cpu(irqCnt, cpu)[SOFTIRQ] = 0; + local_irq_restore(flags); + + per_cpu(irqGet, cpu)[len++] = softirq_key; + per_cpu(irqGet, cpu)[len++] = value; + } + + if (buffer) + *buffer = per_cpu(irqGet, cpu); + + return len; +} + +static struct gator_interface gator_events_irq_interface = { + .create_files = gator_events_irq_create_files, + .online = gator_events_irq_online, + .start = gator_events_irq_start, + .stop = gator_events_irq_stop, + .read = gator_events_irq_read, +}; + +int gator_events_irq_init(void) +{ + hardirq_key = gator_events_get_key(); + softirq_key = gator_events_get_key(); + + hardirq_enabled = 0; + softirq_enabled = 0; + + return gator_events_install(&gator_events_irq_interface); +} +gator_events_init(gator_events_irq_init); |