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authorSteven Rostedt (VMware) <rostedt@goodmis.org>2021-10-15 15:01:19 -0400
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2021-10-19 20:33:20 -0400
commit91ebe8bcbff9d2ff21303e73bf7434f39a98b255 (patch)
treebd54758edff84850b30b9d131fdb1a72bbf470f3
parent9b84fadc444de5456ab5f5487e2108311c724c3f (diff)
tracing/perf: Add interrupt_context_level() helper
Now that there are three different instances of doing the addition trick to the preempt_count() and NMI_MASK, HARDIRQ_MASK and SOFTIRQ_OFFSET macros, it deserves a helper function defined in the preempt.h header. Add the interrupt_context_level() helper and replace the three instances that do that logic with it. Link: https://lore.kernel.org/all/20211015142541.4badd8a9@gandalf.local.home/ Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-rw-r--r--include/linux/preempt.h21
-rw-r--r--include/linux/trace_recursion.h7
-rw-r--r--kernel/events/internal.h7
-rw-r--r--kernel/trace/ring_buffer.c7
4 files changed, 24 insertions, 18 deletions
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index 4d244e295e85..b32e3dabe28b 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -77,6 +77,27 @@
/* preempt_count() and related functions, depends on PREEMPT_NEED_RESCHED */
#include <asm/preempt.h>
+/**
+ * interrupt_context_level - return interrupt context level
+ *
+ * Returns the current interrupt context level.
+ * 0 - normal context
+ * 1 - softirq context
+ * 2 - hardirq context
+ * 3 - NMI context
+ */
+static __always_inline unsigned char interrupt_context_level(void)
+{
+ unsigned long pc = preempt_count();
+ unsigned char level = 0;
+
+ level += !!(pc & (NMI_MASK));
+ level += !!(pc & (NMI_MASK | HARDIRQ_MASK));
+ level += !!(pc & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET));
+
+ return level;
+}
+
#define nmi_count() (preempt_count() & NMI_MASK)
#define hardirq_count() (preempt_count() & HARDIRQ_MASK)
#ifdef CONFIG_PREEMPT_RT
diff --git a/include/linux/trace_recursion.h b/include/linux/trace_recursion.h
index f6da7a03bff0..1d8cce02c3fb 100644
--- a/include/linux/trace_recursion.h
+++ b/include/linux/trace_recursion.h
@@ -136,12 +136,7 @@ enum {
static __always_inline int trace_get_context_bit(void)
{
- unsigned long pc = preempt_count();
- unsigned char bit = 0;
-
- bit += !!(pc & (NMI_MASK));
- bit += !!(pc & (NMI_MASK | HARDIRQ_MASK));
- bit += !!(pc & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET));
+ unsigned char bit = interrupt_context_level();
return TRACE_CTX_NORMAL - bit;
}
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index 228801e20788..082832738c8f 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -205,12 +205,7 @@ DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
static inline int get_recursion_context(int *recursion)
{
- unsigned int pc = preempt_count();
- unsigned char rctx = 0;
-
- rctx += !!(pc & (NMI_MASK));
- rctx += !!(pc & (NMI_MASK | HARDIRQ_MASK));
- rctx += !!(pc & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET));
+ unsigned char rctx = interrupt_context_level();
if (recursion[rctx])
return -1;
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 15d4380006e3..f6520d0a4c8c 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3167,12 +3167,7 @@ static __always_inline int
trace_recursive_lock(struct ring_buffer_per_cpu *cpu_buffer)
{
unsigned int val = cpu_buffer->current_context;
- unsigned long pc = preempt_count();
- int bit = 0;
-
- bit += !!(pc & (NMI_MASK));
- bit += !!(pc & (NMI_MASK | HARDIRQ_MASK));
- bit += !!(pc & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET));
+ int bit = interrupt_context_level();
bit = RB_CTX_NORMAL - bit;