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path: root/drivers/gator/gator_events_irq.c
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Diffstat (limited to 'drivers/gator/gator_events_irq.c')
-rw-r--r--drivers/gator/gator_events_irq.c167
1 files changed, 167 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..b4df7faefff
--- /dev/null
+++ b/drivers/gator/gator_events_irq.c
@@ -0,0 +1,167 @@
+/**
+ * Copyright (C) ARM Limited 2010-2013. 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(atomic_t[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))
+{
+ atomic_inc(&per_cpu(irqCnt, get_physical_cpu())[HARDIRQ]);
+}
+
+#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
+{
+ atomic_inc(&per_cpu(irqCnt, get_physical_cpu())[SOFTIRQ]);
+}
+
+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, bool migrate)
+{
+ int len = 0, cpu = get_physical_cpu();
+
+ // synchronization with the irq_exit functions is not necessary as the values are being reset
+ if (hardirq_enabled) {
+ atomic_set(&per_cpu(irqCnt, cpu)[HARDIRQ], 0);
+ per_cpu(irqGet, cpu)[len++] = hardirq_key;
+ per_cpu(irqGet, cpu)[len++] = 0;
+ }
+
+ if (softirq_enabled) {
+ atomic_set(&per_cpu(irqCnt, cpu)[SOFTIRQ], 0);
+ 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)
+{
+ int len, value;
+ int cpu = get_physical_cpu();
+
+ len = 0;
+ if (hardirq_enabled) {
+ value = atomic_read(&per_cpu(irqCnt, cpu)[HARDIRQ]);
+ atomic_sub(value, &per_cpu(irqCnt, cpu)[HARDIRQ]);
+
+ per_cpu(irqGet, cpu)[len++] = hardirq_key;
+ per_cpu(irqGet, cpu)[len++] = value;
+ }
+
+ if (softirq_enabled) {
+ value = atomic_read(&per_cpu(irqCnt, cpu)[SOFTIRQ]);
+ atomic_sub(value, &per_cpu(irqCnt, cpu)[SOFTIRQ]);
+
+ 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);