linux-kernel - [PATCH v2 5/5] x86: Code clean up for percpu

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date:	Fri, 13 Jan 2012 23:45:20 +0800
From:	Alex Shi <alex.shi@...el.com>
To:	linux-kernel@...r.kernel.org, cl@...two.org,
	eric.dumazet@...il.com, tglx@...utronix.de, avi@...hat.com,
	akpm@...ux-foundation.org, davem@...emloft.net, kaber@...sh.net,
	a.p.zijlstra@...llo.nl, ying.huang@...el.com,
	honrad.wilk@...cle.com, hpa@...or.com, jeremy@...p.org
Subject: [PATCH v2 5/5] x86: Code clean up for percpu_xxx() functions

There is no percpu_xxx serial code in kerenl, so safly remove them.

Signed-off-by: Alex Shi <alex.shi@...el.com>
Acked-by: Christoph Lameter <cl@...two.org>
Acked-by: Tejun Heo <tj@...nel.org>
---
 arch/x86/include/asm/percpu.h |   16 ++++-------
 include/linux/percpu.h        |   54 -----------------------------------------
 2 files changed, 6 insertions(+), 64 deletions(-)

diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index 8d256ad..ed3e18a 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -351,7 +351,7 @@ do {									\
 })
 
 /*
- * percpu_read() makes gcc load the percpu variable every time it is
+ * this_cpu_read() makes gcc load the percpu variable every time it is
  * accessed while this_cpu_read_stable() allows the value to be cached.
  * this_cpu_read_stable() is more efficient and can be used if its value
  * is guaranteed to be valid across cpus.  The current users include
@@ -359,15 +359,7 @@ do {									\
  * per-thread variables implemented as per-cpu variables and thus
  * stable for the duration of the respective task.
  */
-#define percpu_read(var)		percpu_from_op("mov", var, "m" (var))
 #define this_cpu_read_stable(var)	percpu_from_op("mov", var, "p" (&(var)))
-#define percpu_write(var, val)		percpu_to_op("mov", var, val)
-#define percpu_add(var, val)		percpu_add_op(var, val)
-#define percpu_sub(var, val)		percpu_add_op(var, -(val))
-#define percpu_and(var, val)		percpu_to_op("and", var, val)
-#define percpu_or(var, val)		percpu_to_op("or", var, val)
-#define percpu_xor(var, val)		percpu_to_op("xor", var, val)
-#define percpu_inc(var)		percpu_unary_op("inc", var)
 
 #define __this_cpu_read_1(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
 #define __this_cpu_read_2(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
@@ -512,7 +504,11 @@ static __always_inline int x86_this_cpu_constant_test_bit(unsigned int nr,
 {
 	unsigned long __percpu *a = (unsigned long *)addr + nr / BITS_PER_LONG;
 
-	return ((1UL << (nr % BITS_PER_LONG)) & percpu_read(*a)) != 0;
+#ifdef CONFIG_X86_64
+	return ((1UL << (nr % BITS_PER_LONG)) & __this_cpu_read_8(*a)) != 0;
+#else
+	return ((1UL << (nr % BITS_PER_LONG)) & __this_cpu_read_4(*a)) != 0;
+#endif
 }
 
 static inline int x86_this_cpu_variable_test_bit(int nr,
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 32cd1f6..6e68d05 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -166,60 +166,6 @@ extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
 	(typeof(type) __percpu *)__alloc_percpu(sizeof(type), __alignof__(type))
 
 /*
- * Optional methods for optimized non-lvalue per-cpu variable access.
- *
- * @var can be a percpu variable or a field of it and its size should
- * equal char, int or long.  percpu_read() evaluates to a lvalue and
- * all others to void.
- *
- * These operations are guaranteed to be atomic.
- * The generic versions disable interrupts.  Archs are
- * encouraged to implement single-instruction alternatives which don't
- * require protection.
- */
-#ifndef percpu_read
-# define percpu_read(var)						\
-  ({									\
-	typeof(var) *pr_ptr__ = &(var);					\
-	typeof(var) pr_ret__;						\
-	pr_ret__ = get_cpu_var(*pr_ptr__);				\
-	put_cpu_var(*pr_ptr__);						\
-	pr_ret__;							\
-  })
-#endif
-
-#define __percpu_generic_to_op(var, val, op)				\
-do {									\
-	typeof(var) *pgto_ptr__ = &(var);				\
-	get_cpu_var(*pgto_ptr__) op val;				\
-	put_cpu_var(*pgto_ptr__);					\
-} while (0)
-
-#ifndef percpu_write
-# define percpu_write(var, val)		__percpu_generic_to_op(var, (val), =)
-#endif
-
-#ifndef percpu_add
-# define percpu_add(var, val)		__percpu_generic_to_op(var, (val), +=)
-#endif
-
-#ifndef percpu_sub
-# define percpu_sub(var, val)		__percpu_generic_to_op(var, (val), -=)
-#endif
-
-#ifndef percpu_and
-# define percpu_and(var, val)		__percpu_generic_to_op(var, (val), &=)
-#endif
-
-#ifndef percpu_or
-# define percpu_or(var, val)		__percpu_generic_to_op(var, (val), |=)
-#endif
-
-#ifndef percpu_xor
-# define percpu_xor(var, val)		__percpu_generic_to_op(var, (val), ^=)
-#endif
-
-/*
  * Branching function to split up a function into a set of functions that
  * are called for different scalar sizes of the objects handled.
  */
-- 
1.6.3.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/