mutex: move mutex calls to .sched.text

We move mutex calls to its own sub-section, underneath .text.
We'll next try to use the standard section work we've been doing
to see how this will fit as sub-sections within the framework.

readelf -S kernel/locking/mutex.o | grep sched
  [ 6] .sched.text       PROGBITS         0000000000000000  000000b0
  [ 7] .rela.sched.text  RELA             0000000000000000  00001368

When we run ./main:

Initializing x86 bare metal world
x86-init: Number of init entries: 7
Initializing kasan ...
Early init for Kasan...
Completed initializing kasan !
Initializing memory ...
Completed initializing memory !
Initializing kprobes ...
== OK: test_kprobe_0001 within range!
== OK: test_kprobe_0002 not in range as expected!
Completed initializing kprobes !
Initializing pci ...
PCI fixup size: 1
Demo: Using LINKTABLE_FOR_EACH
foo_fixup
Demo: Using LINKTABLE_RUN_ALL
foo_fixup
Completed initializing pci !
Initializing beta ...
Completed initializing beta !
Initializing alpha ...
Completed initializing alpha !
Booting bare metal
Calling start_kernel()...
ACME: Initializing ...
ACME: Finished init ... !
ACME: Running scheduled work

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>

4 files changed, 12 insertions, 4 deletions

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index e7378cc..cd91080 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -66,6 +66,7 @@ SECTIONS
     *(SORT(SECTION_TBL_ALL(SECTION_INIT_CALL)))
     *(SORT(SECTION_TBL_ALL(SECTION_EXIT)))
     *(SORT(SECTION_TBL_ALL(SECTION_EXIT_CALL)))
+    *(.sched.text)
     *(.text .stub .text.* .gnu.linkonce.t.*)
     /* .gnu.warning sections are handled specially by elf32.em.  */
     *(.gnu.warning)
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index f8134ec..4d0bb0e 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -1,6 +1,7 @@
 #ifndef __LINUX_MUTEX_H
 #define __LINUX_MUTEX_H
 
+#include <linux/sched.h>
 #include <pthread.h>
 
 struct mutex {
diff --git a/include/linux/sched.h b/include/linux/sched.h
new file mode 100644
index 0000000..b98d955
--- /dev/null
+++ b/include/linux/sched.h
@@ -0,0 +1,6 @@
+#ifndef _LINUX_SCHED_H
+#define _LINUX_SCHED_H
+
+#define __sched		__attribute__((__section__(".sched.text")))
+
+#endif /* _LINUX_SCHED_H */
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 21e6212..a97800e 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -1,7 +1,7 @@
 #include <linux/kernel.h>
 #include <linux/mutex.h>
 
-void mutex_init(struct mutex *lock)
+void __sched mutex_init(struct mutex *lock)
 {
 	int r;
 
@@ -10,17 +10,17 @@ void mutex_init(struct mutex *lock)
 		BUG_ON(r);
 }
 
-void mutex_destroy(struct mutex *lock)
+void __sched mutex_destroy(struct mutex *lock)
 {
 	pthread_mutex_destroy(&lock->lock);
 }
 
-void mutex_lock(struct mutex *lock)
+void __sched mutex_lock(struct mutex *lock)
 {
 	pthread_mutex_lock(&lock->lock);
 }
 
-void mutex_unlock(struct mutex *lock)
+void __sched mutex_unlock(struct mutex *lock)
 {
 	pthread_mutex_unlock(&lock->lock);
 }