hexagon/CPU hotplug: Add missing call to notify_cpu_starting()

[karo-tx-linux.git] / kernel / trace / ring_buffer.c

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index f5b7b5c1195beaf806f19d59e0ce7114c0e36add..cf8d11e91efdf92d95dad58d6fa771d2ac998786 100644 (file)
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -154,33 +154,10 @@ enum {
 
 static unsigned long ring_buffer_flags __read_mostly = RB_BUFFERS_ON;
 
-#define BUF_PAGE_HDR_SIZE offsetof(struct buffer_data_page, data)
-
-/**
- * tracing_on - enable all tracing buffers
- *
- * This function enables all tracing buffers that may have been
- * disabled with tracing_off.
- */
-void tracing_on(void)
-{
-       set_bit(RB_BUFFERS_ON_BIT, &ring_buffer_flags);
-}
-EXPORT_SYMBOL_GPL(tracing_on);
+/* Used for individual buffers (after the counter) */
+#define RB_BUFFER_OFF          (1 << 20)
 
-/**
- * tracing_off - turn off all tracing buffers
- *
- * This function stops all tracing buffers from recording data.
- * It does not disable any overhead the tracers themselves may
- * be causing. This function simply causes all recording to
- * the ring buffers to fail.
- */
-void tracing_off(void)
-{
-       clear_bit(RB_BUFFERS_ON_BIT, &ring_buffer_flags);
-}
-EXPORT_SYMBOL_GPL(tracing_off);
+#define BUF_PAGE_HDR_SIZE offsetof(struct buffer_data_page, data)
 
 /**
  * tracing_off_permanent - permanently disable ring buffers
@@ -193,15 +170,6 @@ void tracing_off_permanent(void)
        set_bit(RB_BUFFERS_DISABLED_BIT, &ring_buffer_flags);
 }
 
-/**
- * tracing_is_on - show state of ring buffers enabled
- */
-int tracing_is_on(void)
-{
-       return ring_buffer_flags == RB_BUFFERS_ON;
-}
-EXPORT_SYMBOL_GPL(tracing_is_on);
-
 #define RB_EVNT_HDR_SIZE (offsetof(struct ring_buffer_event, array))
 #define RB_ALIGNMENT           4U
 #define RB_MAX_SMALL_DATA      (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX)
@@ -2618,6 +2586,63 @@ void ring_buffer_record_enable(struct ring_buffer *buffer)
 }
 EXPORT_SYMBOL_GPL(ring_buffer_record_enable);
 
+/**
+ * ring_buffer_record_off - stop all writes into the buffer
+ * @buffer: The ring buffer to stop writes to.
+ *
+ * This prevents all writes to the buffer. Any attempt to write
+ * to the buffer after this will fail and return NULL.
+ *
+ * This is different than ring_buffer_record_disable() as
+ * it works like an on/off switch, where as the disable() verison
+ * must be paired with a enable().
+ */
+void ring_buffer_record_off(struct ring_buffer *buffer)
+{
+       unsigned int rd;
+       unsigned int new_rd;
+
+       do {
+               rd = atomic_read(&buffer->record_disabled);
+               new_rd = rd | RB_BUFFER_OFF;
+       } while (atomic_cmpxchg(&buffer->record_disabled, rd, new_rd) != rd);
+}
+EXPORT_SYMBOL_GPL(ring_buffer_record_off);
+
+/**
+ * ring_buffer_record_on - restart writes into the buffer
+ * @buffer: The ring buffer to start writes to.
+ *
+ * This enables all writes to the buffer that was disabled by
+ * ring_buffer_record_off().
+ *
+ * This is different than ring_buffer_record_enable() as
+ * it works like an on/off switch, where as the enable() verison
+ * must be paired with a disable().
+ */
+void ring_buffer_record_on(struct ring_buffer *buffer)
+{
+       unsigned int rd;
+       unsigned int new_rd;
+
+       do {
+               rd = atomic_read(&buffer->record_disabled);
+               new_rd = rd & ~RB_BUFFER_OFF;
+       } while (atomic_cmpxchg(&buffer->record_disabled, rd, new_rd) != rd);
+}
+EXPORT_SYMBOL_GPL(ring_buffer_record_on);
+
+/**
+ * ring_buffer_record_is_on - return true if the ring buffer can write
+ * @buffer: The ring buffer to see if write is enabled
+ *
+ * Returns true if the ring buffer is in a state that it accepts writes.
+ */
+int ring_buffer_record_is_on(struct ring_buffer *buffer)
+{
+       return !atomic_read(&buffer->record_disabled);
+}
+
 /**
  * ring_buffer_record_disable_cpu - stop all writes into the cpu_buffer
  * @buffer: The ring buffer to stop writes to.
@@ -4039,68 +4064,6 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
 }
 EXPORT_SYMBOL_GPL(ring_buffer_read_page);
 
-#ifdef CONFIG_TRACING
-static ssize_t
-rb_simple_read(struct file *filp, char __user *ubuf,
-              size_t cnt, loff_t *ppos)
-{
-       unsigned long *p = filp->private_data;
-       char buf[64];
-       int r;
-
-       if (test_bit(RB_BUFFERS_DISABLED_BIT, p))
-               r = sprintf(buf, "permanently disabled\n");
-       else
-               r = sprintf(buf, "%d\n", test_bit(RB_BUFFERS_ON_BIT, p));
-
-       return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
-}
-
-static ssize_t
-rb_simple_write(struct file *filp, const char __user *ubuf,
-               size_t cnt, loff_t *ppos)
-{
-       unsigned long *p = filp->private_data;
-       unsigned long val;
-       int ret;
-
-       ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
-       if (ret)
-               return ret;
-
-       if (val)
-               set_bit(RB_BUFFERS_ON_BIT, p);
-       else
-               clear_bit(RB_BUFFERS_ON_BIT, p);
-
-       (*ppos)++;
-
-       return cnt;
-}
-
-static const struct file_operations rb_simple_fops = {
-       .open           = tracing_open_generic,
-       .read           = rb_simple_read,
-       .write          = rb_simple_write,
-       .llseek         = default_llseek,
-};
-
-
-static __init int rb_init_debugfs(void)
-{
-       struct dentry *d_tracer;
-
-       d_tracer = tracing_init_dentry();
-
-       trace_create_file("tracing_on", 0644, d_tracer,
-                           &ring_buffer_flags, &rb_simple_fops);
-
-       return 0;
-}
-
-fs_initcall(rb_init_debugfs);
-#endif
-
 #ifdef CONFIG_HOTPLUG_CPU
 static int rb_cpu_notify(struct notifier_block *self,
                         unsigned long action, void *hcpu)