x86/percpu: Introduce raw_cpu_read_long() to reduce ifdeffery

Introduce raw_cpu_read_long() macro to slightly reduce ifdeffery
in <asm/percpu.h>.

No functional changes intended.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240404094218.448963-3-ubizjak@gmail.com

Author: ubizjak

arch/x86/include/asm/percpu.h

@@ -59,12 +59,6 @@
 #define __force_percpu_prefix	"%%"__stringify(__percpu_seg)":"
 #define __my_cpu_offset		this_cpu_read(this_cpu_off)
 
-#ifdef CONFIG_X86_64
-#define __raw_my_cpu_offset	raw_cpu_read_8(this_cpu_off);
-#else
-#define __raw_my_cpu_offset	raw_cpu_read_4(this_cpu_off);
-#endif
-
 /*
  * Compared to the generic __my_cpu_offset version, the following
  * saves one instruction and avoids clobbering a temp register.
@@ -76,7 +70,7 @@
 #ifndef BUILD_VDSO32_64
 #define arch_raw_cpu_ptr(_ptr)					\
 ({								\
-	unsigned long tcp_ptr__ = __raw_my_cpu_offset;		\
+	unsigned long tcp_ptr__ = raw_cpu_read_long(this_cpu_off); \
 	tcp_ptr__ += (__force unsigned long)(_ptr);		\
 	(typeof(*(_ptr)) __kernel __force *)tcp_ptr__;		\
 })
@@ -563,9 +557,13 @@ do {									\
 #define this_cpu_xchg_8(pcp, nval)		this_percpu_xchg_op(pcp, nval)
 #define this_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(8, volatile, pcp, oval, nval)
 #define this_cpu_try_cmpxchg_8(pcp, ovalp, nval)	percpu_try_cmpxchg_op(8, volatile, pcp, ovalp, nval)
+
+#define raw_cpu_read_long(pcp)		raw_cpu_read_8(pcp)
 #else
 /* There is no generic 64 bit read stable operation for 32 bit targets. */
-#define this_cpu_read_stable_8(pcp)    ({ BUILD_BUG(); (typeof(pcp))0; })
+#define this_cpu_read_stable_8(pcp)	({ BUILD_BUG(); (typeof(pcp))0; })
+
+#define raw_cpu_read_long(pcp)		raw_cpu_read_4(pcp)
 #endif
 
 #define x86_this_cpu_constant_test_bit(_nr, _var)			\