[GIT PULL] x86/atomic changes for v3.4

From: Ingo Molnar
Date: Mon Mar 19 2012 - 12:20:10 EST

Linus,

Please pull the latest x86-atomic-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-atomic-for-linus

HEAD: cb8095bba6d24118135a5683a956f4f4fb5f17bb x86: atomic64 assembly improvements

Thanks,

Ingo

------------------>
Jan Beulich (2):
x86: Adjust asm constraints in atomic64 wrappers
x86: atomic64 assembly improvements


arch/x86/include/asm/alternative.h | 6 ++
arch/x86/include/asm/atomic64_32.h | 146 +++++++++++++++++++----------------
arch/x86/lib/atomic64_32.c | 59 +--------------
arch/x86/lib/atomic64_386_32.S | 6 +-
arch/x86/lib/atomic64_cx8_32.S | 29 +++-----
5 files changed, 101 insertions(+), 145 deletions(-)

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 37ad100..49331be 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -145,6 +145,12 @@ static inline int alternatives_text_reserved(void *start, void *end)
*/
#define ASM_OUTPUT2(a...) a

+/*
+ * use this macro if you need clobbers but no inputs in
+ * alternative_{input,io,call}()
+ */
+#define ASM_NO_INPUT_CLOBBER(clbr...) "i" (0) : clbr
+
struct paravirt_patch_site;
#ifdef CONFIG_PARAVIRT
void apply_paravirt(struct paravirt_patch_site *start,
diff --git a/arch/x86/include/asm/atomic64_32.h b/arch/x86/include/asm/atomic64_32.h
index fa13f0e..1981199 100644
--- a/arch/x86/include/asm/atomic64_32.h
+++ b/arch/x86/include/asm/atomic64_32.h
@@ -14,13 +14,52 @@ typedef struct {

#define ATOMIC64_INIT(val) { (val) }

+#define __ATOMIC64_DECL(sym) void atomic64_##sym(atomic64_t *, ...)
+#ifndef ATOMIC64_EXPORT
+#define ATOMIC64_DECL_ONE __ATOMIC64_DECL
+#else
+#define ATOMIC64_DECL_ONE(sym) __ATOMIC64_DECL(sym); \
+ ATOMIC64_EXPORT(atomic64_##sym)
+#endif
+
#ifdef CONFIG_X86_CMPXCHG64
-#define ATOMIC64_ALTERNATIVE_(f, g) "call atomic64_" #g "_cx8"
+#define __alternative_atomic64(f, g, out, in...) \
+ asm volatile("call %P[func]" \
+ : out : [func] "i" (atomic64_##g##_cx8), ## in)
+
+#define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8)
#else
-#define ATOMIC64_ALTERNATIVE_(f, g) ALTERNATIVE("call atomic64_" #f "_386", "call atomic64_" #g "_cx8", X86_FEATURE_CX8)
+#define __alternative_atomic64(f, g, out, in...) \
+ alternative_call(atomic64_##f##_386, atomic64_##g##_cx8, \
+ X86_FEATURE_CX8, ASM_OUTPUT2(out), ## in)
+
+#define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8); \
+ ATOMIC64_DECL_ONE(sym##_386)
+
+ATOMIC64_DECL_ONE(add_386);
+ATOMIC64_DECL_ONE(sub_386);
+ATOMIC64_DECL_ONE(inc_386);
+ATOMIC64_DECL_ONE(dec_386);
#endif

-#define ATOMIC64_ALTERNATIVE(f) ATOMIC64_ALTERNATIVE_(f, f)
+#define alternative_atomic64(f, out, in...) \
+ __alternative_atomic64(f, f, ASM_OUTPUT2(out), ## in)
+
+ATOMIC64_DECL(read);
+ATOMIC64_DECL(set);
+ATOMIC64_DECL(xchg);
+ATOMIC64_DECL(add_return);
+ATOMIC64_DECL(sub_return);
+ATOMIC64_DECL(inc_return);
+ATOMIC64_DECL(dec_return);
+ATOMIC64_DECL(dec_if_positive);
+ATOMIC64_DECL(inc_not_zero);
+ATOMIC64_DECL(add_unless);
+
+#undef ATOMIC64_DECL
+#undef ATOMIC64_DECL_ONE
+#undef __ATOMIC64_DECL
+#undef ATOMIC64_EXPORT

/**
* atomic64_cmpxchg - cmpxchg atomic64 variable
@@ -50,11 +89,9 @@ static inline long long atomic64_xchg(atomic64_t *v, long long n)
long long o;
unsigned high = (unsigned)(n >> 32);
unsigned low = (unsigned)n;
- asm volatile(ATOMIC64_ALTERNATIVE(xchg)
- : "=A" (o), "+b" (low), "+c" (high)
- : "S" (v)
- : "memory"
- );
+ alternative_atomic64(xchg, "=&A" (o),
+ "S" (v), "b" (low), "c" (high)
+ : "memory");
return o;
}

@@ -69,11 +106,9 @@ static inline void atomic64_set(atomic64_t *v, long long i)
{
unsigned high = (unsigned)(i >> 32);
unsigned low = (unsigned)i;
- asm volatile(ATOMIC64_ALTERNATIVE(set)
- : "+b" (low), "+c" (high)
- : "S" (v)
- : "eax", "edx", "memory"
- );
+ alternative_atomic64(set, /* no output */,
+ "S" (v), "b" (low), "c" (high)
+ : "eax", "edx", "memory");
}

/**
@@ -85,10 +120,7 @@ static inline void atomic64_set(atomic64_t *v, long long i)
static inline long long atomic64_read(const atomic64_t *v)
{
long long r;
- asm volatile(ATOMIC64_ALTERNATIVE(read)
- : "=A" (r), "+c" (v)
- : : "memory"
- );
+ alternative_atomic64(read, "=&A" (r), "c" (v) : "memory");
return r;
}

@@ -101,10 +133,9 @@ static inline long long atomic64_read(const atomic64_t *v)
*/
static inline long long atomic64_add_return(long long i, atomic64_t *v)
{
- asm volatile(ATOMIC64_ALTERNATIVE(add_return)
- : "+A" (i), "+c" (v)
- : : "memory"
- );
+ alternative_atomic64(add_return,
+ ASM_OUTPUT2("+A" (i), "+c" (v)),
+ ASM_NO_INPUT_CLOBBER("memory"));
return i;
}

@@ -113,32 +144,25 @@ static inline long long atomic64_add_return(long long i, atomic64_t *v)
*/
static inline long long atomic64_sub_return(long long i, atomic64_t *v)
{
- asm volatile(ATOMIC64_ALTERNATIVE(sub_return)
- : "+A" (i), "+c" (v)
- : : "memory"
- );
+ alternative_atomic64(sub_return,
+ ASM_OUTPUT2("+A" (i), "+c" (v)),
+ ASM_NO_INPUT_CLOBBER("memory"));
return i;
}

static inline long long atomic64_inc_return(atomic64_t *v)
{
long long a;
- asm volatile(ATOMIC64_ALTERNATIVE(inc_return)
- : "=A" (a)
- : "S" (v)
- : "memory", "ecx"
- );
+ alternative_atomic64(inc_return, "=&A" (a),
+ "S" (v) : "memory", "ecx");
return a;
}

static inline long long atomic64_dec_return(atomic64_t *v)
{
long long a;
- asm volatile(ATOMIC64_ALTERNATIVE(dec_return)
- : "=A" (a)
- : "S" (v)
- : "memory", "ecx"
- );
+ alternative_atomic64(dec_return, "=&A" (a),
+ "S" (v) : "memory", "ecx");
return a;
}

@@ -151,10 +175,9 @@ static inline long long atomic64_dec_return(atomic64_t *v)
*/
static inline long long atomic64_add(long long i, atomic64_t *v)
{
- asm volatile(ATOMIC64_ALTERNATIVE_(add, add_return)
- : "+A" (i), "+c" (v)
- : : "memory"
- );
+ __alternative_atomic64(add, add_return,
+ ASM_OUTPUT2("+A" (i), "+c" (v)),
+ ASM_NO_INPUT_CLOBBER("memory"));
return i;
}

@@ -167,10 +190,9 @@ static inline long long atomic64_add(long long i, atomic64_t *v)
*/
static inline long long atomic64_sub(long long i, atomic64_t *v)
{
- asm volatile(ATOMIC64_ALTERNATIVE_(sub, sub_return)
- : "+A" (i), "+c" (v)
- : : "memory"
- );
+ __alternative_atomic64(sub, sub_return,
+ ASM_OUTPUT2("+A" (i), "+c" (v)),
+ ASM_NO_INPUT_CLOBBER("memory"));
return i;
}

@@ -196,10 +218,8 @@ static inline int atomic64_sub_and_test(long long i, atomic64_t *v)
*/
static inline void atomic64_inc(atomic64_t *v)
{
- asm volatile(ATOMIC64_ALTERNATIVE_(inc, inc_return)
- : : "S" (v)
- : "memory", "eax", "ecx", "edx"
- );
+ __alternative_atomic64(inc, inc_return, /* no output */,
+ "S" (v) : "memory", "eax", "ecx", "edx");
}

/**
@@ -210,10 +230,8 @@ static inline void atomic64_inc(atomic64_t *v)
*/
static inline void atomic64_dec(atomic64_t *v)
{
- asm volatile(ATOMIC64_ALTERNATIVE_(dec, dec_return)
- : : "S" (v)
- : "memory", "eax", "ecx", "edx"
- );
+ __alternative_atomic64(dec, dec_return, /* no output */,
+ "S" (v) : "memory", "eax", "ecx", "edx");
}

/**
@@ -263,15 +281,15 @@ static inline int atomic64_add_negative(long long i, atomic64_t *v)
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, so long as it was not @u.
- * Returns the old value of @v.
+ * Returns non-zero if the add was done, zero otherwise.
*/
static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
{
unsigned low = (unsigned)u;
unsigned high = (unsigned)(u >> 32);
- asm volatile(ATOMIC64_ALTERNATIVE(add_unless) "\n\t"
- : "+A" (a), "+c" (v), "+S" (low), "+D" (high)
- : : "memory");
+ alternative_atomic64(add_unless,
+ ASM_OUTPUT2("+A" (a), "+c" (low), "+D" (high)),
+ "S" (v) : "memory");
return (int)a;
}

@@ -279,26 +297,20 @@ static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
static inline int atomic64_inc_not_zero(atomic64_t *v)
{
int r;
- asm volatile(ATOMIC64_ALTERNATIVE(inc_not_zero)
- : "=a" (r)
- : "S" (v)
- : "ecx", "edx", "memory"
- );
+ alternative_atomic64(inc_not_zero, "=&a" (r),
+ "S" (v) : "ecx", "edx", "memory");
return r;
}

static inline long long atomic64_dec_if_positive(atomic64_t *v)
{
long long r;
- asm volatile(ATOMIC64_ALTERNATIVE(dec_if_positive)
- : "=A" (r)
- : "S" (v)
- : "ecx", "memory"
- );
+ alternative_atomic64(dec_if_positive, "=&A" (r),
+ "S" (v) : "ecx", "memory");
return r;
}

-#undef ATOMIC64_ALTERNATIVE
-#undef ATOMIC64_ALTERNATIVE_
+#undef alternative_atomic64
+#undef __alternative_atomic64

#endif /* _ASM_X86_ATOMIC64_32_H */
diff --git a/arch/x86/lib/atomic64_32.c b/arch/x86/lib/atomic64_32.c
index 042f682..a0b4a35 100644
--- a/arch/x86/lib/atomic64_32.c
+++ b/arch/x86/lib/atomic64_32.c
@@ -1,59 +1,4 @@
-#include <linux/compiler.h>
-#include <linux/module.h>
-#include <linux/types.h>
+#define ATOMIC64_EXPORT EXPORT_SYMBOL

-#include <asm/processor.h>
-#include <asm/cmpxchg.h>
+#include <linux/export.h>
#include <linux/atomic.h>
-
-long long atomic64_read_cx8(long long, const atomic64_t *v);
-EXPORT_SYMBOL(atomic64_read_cx8);
-long long atomic64_set_cx8(long long, const atomic64_t *v);
-EXPORT_SYMBOL(atomic64_set_cx8);
-long long atomic64_xchg_cx8(long long, unsigned high);
-EXPORT_SYMBOL(atomic64_xchg_cx8);
-long long atomic64_add_return_cx8(long long a, atomic64_t *v);
-EXPORT_SYMBOL(atomic64_add_return_cx8);
-long long atomic64_sub_return_cx8(long long a, atomic64_t *v);
-EXPORT_SYMBOL(atomic64_sub_return_cx8);
-long long atomic64_inc_return_cx8(long long a, atomic64_t *v);
-EXPORT_SYMBOL(atomic64_inc_return_cx8);
-long long atomic64_dec_return_cx8(long long a, atomic64_t *v);
-EXPORT_SYMBOL(atomic64_dec_return_cx8);
-long long atomic64_dec_if_positive_cx8(atomic64_t *v);
-EXPORT_SYMBOL(atomic64_dec_if_positive_cx8);
-int atomic64_inc_not_zero_cx8(atomic64_t *v);
-EXPORT_SYMBOL(atomic64_inc_not_zero_cx8);
-int atomic64_add_unless_cx8(atomic64_t *v, long long a, long long u);
-EXPORT_SYMBOL(atomic64_add_unless_cx8);
-
-#ifndef CONFIG_X86_CMPXCHG64
-long long atomic64_read_386(long long, const atomic64_t *v);
-EXPORT_SYMBOL(atomic64_read_386);
-long long atomic64_set_386(long long, const atomic64_t *v);
-EXPORT_SYMBOL(atomic64_set_386);
-long long atomic64_xchg_386(long long, unsigned high);
-EXPORT_SYMBOL(atomic64_xchg_386);
-long long atomic64_add_return_386(long long a, atomic64_t *v);
-EXPORT_SYMBOL(atomic64_add_return_386);
-long long atomic64_sub_return_386(long long a, atomic64_t *v);
-EXPORT_SYMBOL(atomic64_sub_return_386);
-long long atomic64_inc_return_386(long long a, atomic64_t *v);
-EXPORT_SYMBOL(atomic64_inc_return_386);
-long long atomic64_dec_return_386(long long a, atomic64_t *v);
-EXPORT_SYMBOL(atomic64_dec_return_386);
-long long atomic64_add_386(long long a, atomic64_t *v);
-EXPORT_SYMBOL(atomic64_add_386);
-long long atomic64_sub_386(long long a, atomic64_t *v);
-EXPORT_SYMBOL(atomic64_sub_386);
-long long atomic64_inc_386(long long a, atomic64_t *v);
-EXPORT_SYMBOL(atomic64_inc_386);
-long long atomic64_dec_386(long long a, atomic64_t *v);
-EXPORT_SYMBOL(atomic64_dec_386);
-long long atomic64_dec_if_positive_386(atomic64_t *v);
-EXPORT_SYMBOL(atomic64_dec_if_positive_386);
-int atomic64_inc_not_zero_386(atomic64_t *v);
-EXPORT_SYMBOL(atomic64_inc_not_zero_386);
-int atomic64_add_unless_386(atomic64_t *v, long long a, long long u);
-EXPORT_SYMBOL(atomic64_add_unless_386);
-#endif
diff --git a/arch/x86/lib/atomic64_386_32.S b/arch/x86/lib/atomic64_386_32.S
index e8e7e0d..00933d5 100644
--- a/arch/x86/lib/atomic64_386_32.S
+++ b/arch/x86/lib/atomic64_386_32.S
@@ -137,13 +137,13 @@ BEGIN(dec_return)
RET_ENDP
#undef v

-#define v %ecx
+#define v %esi
BEGIN(add_unless)
- addl %eax, %esi
+ addl %eax, %ecx
adcl %edx, %edi
addl (v), %eax
adcl 4(v), %edx
- cmpl %eax, %esi
+ cmpl %eax, %ecx
je 3f
1:
movl %eax, (v)
diff --git a/arch/x86/lib/atomic64_cx8_32.S b/arch/x86/lib/atomic64_cx8_32.S
index 391a083..f5cc9eb 100644
--- a/arch/x86/lib/atomic64_cx8_32.S
+++ b/arch/x86/lib/atomic64_cx8_32.S
@@ -55,8 +55,6 @@ ENDPROC(atomic64_set_cx8)
ENTRY(atomic64_xchg_cx8)
CFI_STARTPROC

- movl %ebx, %eax
- movl %ecx, %edx
1:
LOCK_PREFIX
cmpxchg8b (%esi)
@@ -78,7 +76,7 @@ ENTRY(atomic64_\func\()_return_cx8)
movl %edx, %edi
movl %ecx, %ebp

- read64 %ebp
+ read64 %ecx
1:
movl %eax, %ebx
movl %edx, %ecx
@@ -159,23 +157,22 @@ ENTRY(atomic64_add_unless_cx8)
SAVE ebx
/* these just push these two parameters on the stack */
SAVE edi
- SAVE esi
+ SAVE ecx

- movl %ecx, %ebp
- movl %eax, %esi
+ movl %eax, %ebp
movl %edx, %edi

- read64 %ebp
+ read64 %esi
1:
cmpl %eax, 0(%esp)
je 4f
2:
movl %eax, %ebx
movl %edx, %ecx
- addl %esi, %ebx
+ addl %ebp, %ebx
adcl %edi, %ecx
LOCK_PREFIX
- cmpxchg8b (%ebp)
+ cmpxchg8b (%esi)
jne 1b

movl $1, %eax
@@ -199,13 +196,13 @@ ENTRY(atomic64_inc_not_zero_cx8)

read64 %esi
1:
- testl %eax, %eax
- je 4f
-2:
+ movl %eax, %ecx
+ orl %edx, %ecx
+ jz 3f
movl %eax, %ebx
- movl %edx, %ecx
+ xorl %ecx, %ecx
addl $1, %ebx
- adcl $0, %ecx
+ adcl %edx, %ecx
LOCK_PREFIX
cmpxchg8b (%esi)
jne 1b
@@ -214,9 +211,5 @@ ENTRY(atomic64_inc_not_zero_cx8)
3:
RESTORE ebx
ret
-4:
- testl %edx, %edx
- jne 2b
- jmp 3b
CFI_ENDPROC
ENDPROC(atomic64_inc_not_zero_cx8)
--
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