The patch introduces per_cpu_qual define and repurposes __percpu
tag as a named address space qualifier using the new define.
Arches can now conditionally define __per_cpu_qual as their
named address space qualifier for percpu variables.
Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Dennis Zhou <dennis@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
Cc: Nadav Amit <nadav.amit@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
include/asm-generic/percpu.h | 15 +++++++++++++++
include/linux/compiler_types.h | 2 +-
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index 50597b975a49..3b93b168faa1 100644
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -6,6 +6,21 @@
#include <linux/threads.h>
#include <linux/percpu-defs.h>
+/*
+ * per_cpu_qual is the qualifier for the percpu named address space.
+ *
+ * Most arches use generic named address space for percpu variables but
+ * some arches define percpu variables in different named address space
+ * (on the x86 arch, percpu variable may be declared as being relative
+ * to the %fs or %gs segments using __seg_fs or __seg_gs named address
+ * space qualifier).
+ */
+#ifdef __per_cpu_qual
+# define per_cpu_qual __per_cpu_qual
+#else
+# define per_cpu_qual
+#endif
+
#ifdef CONFIG_SMP
/*
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 981cc3d7e3aa..877fe0c43c5d 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -57,7 +57,7 @@ static inline void __chk_io_ptr(const volatile void __iomem *ptr) { }
# define __user BTF_TYPE_TAG(user)
# endif
# define __iomem
-# define __percpu BTF_TYPE_TAG(percpu)
+# define __percpu per_cpu_qual BTF_TYPE_TAG(percpu)
# define __rcu BTF_TYPE_TAG(rcu)
# define __chk_user_ptr(x) (void)0
--
2.42.0
