x86/asm: Remove semicolon from LOCK prefix

Most of Xen's LOCK prefixes are already without semicolon, but we have a few
still remaining in the tree.

As noted in the Linux patch, this adversely affects size/inlining decisions,
and prevents the assembler from diagnosing certain classes of error.

No functional change.

Link: https://lore.kernel.org/lkml/20250228085149.2478245-1-ubizjak@gmail.com/
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>

diff --git a/xen/arch/x86/include/asm/atomic.h b/xen/arch/x86/include/asm/atomic.h
index 16bd0ebfd76351c82420a24c8a81fc7795600687..ed4e09a50329038ec54c29c952d386c0e1b83cb3 100644 (file)
--- a/xen/arch/x86/include/asm/atomic.h
+++ b/xen/arch/x86/include/asm/atomic.h
@@ -115,7 +115,7 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
 static inline void atomic_add(int i, atomic_t *v)
 {
     asm volatile (
-        "lock; addl %1,%0"
+        "lock addl %1,%0"
         : "=m" (*(volatile int *)&v->counter)
         : "ir" (i), "m" (*(volatile int *)&v->counter) );
 }
@@ -128,7 +128,7 @@ static inline int atomic_add_return(int i, atomic_t *v)
 static inline void atomic_sub(int i, atomic_t *v)
 {
     asm volatile (
-        "lock; subl %1,%0"
+        "lock subl %1,%0"
         : "=m" (*(volatile int *)&v->counter)
         : "ir" (i), "m" (*(volatile int *)&v->counter) );
 }
@@ -142,7 +142,7 @@ static inline int atomic_sub_and_test(int i, atomic_t *v)
 {
     bool c;
 
-    asm volatile ( "lock; subl %[i], %[counter]\n\t"
+    asm volatile ( "lock subl %[i], %[counter]\n\t"
                    ASM_FLAG_OUT(, "setz %[zf]\n\t")
                    : [counter] "+m" (*(volatile int *)&v->counter),
                      [zf] ASM_FLAG_OUT("=@ccz", "=qm") (c)
@@ -154,7 +154,7 @@ static inline int atomic_sub_and_test(int i, atomic_t *v)
 static inline void atomic_inc(atomic_t *v)
 {
     asm volatile (
-        "lock; incl %0"
+        "lock incl %0"
         : "=m" (*(volatile int *)&v->counter)
         : "m" (*(volatile int *)&v->counter) );
 }
@@ -168,7 +168,7 @@ static inline int atomic_inc_and_test(atomic_t *v)
 {
     bool c;
 
-    asm volatile ( "lock; incl %[counter]\n\t"
+    asm volatile ( "lock incl %[counter]\n\t"
                    ASM_FLAG_OUT(, "setz %[zf]\n\t")
                    : [counter] "+m" (*(volatile int *)&v->counter),
                      [zf] ASM_FLAG_OUT("=@ccz", "=qm") (c)
@@ -180,7 +180,7 @@ static inline int atomic_inc_and_test(atomic_t *v)
 static inline void atomic_dec(atomic_t *v)
 {
     asm volatile (
-        "lock; decl %0"
+        "lock decl %0"
         : "=m" (*(volatile int *)&v->counter)
         : "m" (*(volatile int *)&v->counter) );
 }
@@ -194,7 +194,7 @@ static inline int atomic_dec_and_test(atomic_t *v)
 {
     bool c;
 
-    asm volatile ( "lock; decl %[counter]\n\t"
+    asm volatile ( "lock decl %[counter]\n\t"
                    ASM_FLAG_OUT(, "setz %[zf]\n\t")
                    : [counter] "+m" (*(volatile int *)&v->counter),
                      [zf] ASM_FLAG_OUT("=@ccz", "=qm") (c)
@@ -207,7 +207,7 @@ static inline int atomic_add_negative(int i, atomic_t *v)
 {
     bool c;
 
-    asm volatile ( "lock; addl %[i], %[counter]\n\t"
+    asm volatile ( "lock addl %[i], %[counter]\n\t"
                    ASM_FLAG_OUT(, "sets %[sf]\n\t")
                    : [counter] "+m" (*(volatile int *)&v->counter),
                      [sf] ASM_FLAG_OUT("=@ccs", "=qm") (c)

diff --git a/xen/arch/x86/include/asm/bitops.h b/xen/arch/x86/include/asm/bitops.h
index 39e37f1cbe5598759077840717b5edcb574c6a6f..bb9d7564602321e7933b0952ba4b8e8c4fbfe244 100644 (file)
--- a/xen/arch/x86/include/asm/bitops.h
+++ b/xen/arch/x86/include/asm/bitops.h
@@ -32,7 +32,7 @@
  */
 static inline void set_bit(int nr, volatile void *addr)
 {
-    asm volatile ( "lock; btsl %1,%0"
+    asm volatile ( "lock btsl %1,%0"
                    : "+m" (ADDR) : "Ir" (nr) : "memory");
 }
 #define set_bit(nr, addr) ({                            \
@@ -73,7 +73,7 @@ static inline void constant_set_bit(int nr, void *addr)
  */
 static inline void clear_bit(int nr, volatile void *addr)
 {
-    asm volatile ( "lock; btrl %1,%0"
+    asm volatile ( "lock btrl %1,%0"
                    : "+m" (ADDR) : "Ir" (nr) : "memory");
 }
 #define clear_bit(nr, addr) ({                          \
@@ -140,7 +140,7 @@ static inline void constant_change_bit(int nr, void *addr)
  */
 static inline void change_bit(int nr, volatile void *addr)
 {
-    asm volatile ( "lock; btcl %1,%0"
+    asm volatile ( "lock btcl %1,%0"
                     : "+m" (ADDR) : "Ir" (nr) : "memory");
 }
 #define change_bit(nr, addr) ({                         \
@@ -160,7 +160,7 @@ static inline int test_and_set_bit(int nr, volatile void *addr)
 {
     int oldbit;
 
-    asm volatile ( "lock; btsl %[nr], %[addr]\n\t"
+    asm volatile ( "lock btsl %[nr], %[addr]\n\t"
                    ASM_FLAG_OUT(, "sbbl %[old], %[old]\n\t")
                    : [old] ASM_FLAG_OUT("=@ccc", "=r") (oldbit),
                      [addr] "+m" (ADDR) : [nr] "Ir" (nr) : "memory" );
@@ -206,7 +206,7 @@ static inline int test_and_clear_bit(int nr, volatile void *addr)
 {
     int oldbit;
 
-    asm volatile ( "lock; btrl %[nr], %[addr]\n\t"
+    asm volatile ( "lock btrl %[nr], %[addr]\n\t"
                    ASM_FLAG_OUT(, "sbbl %[old], %[old]\n\t")
                    : [old] ASM_FLAG_OUT("=@ccc", "=r") (oldbit),
                      [addr] "+m" (ADDR) : [nr] "Ir" (nr) : "memory" );
@@ -266,7 +266,7 @@ static inline int test_and_change_bit(int nr, volatile void *addr)
 {
     int oldbit;
 
-    asm volatile ( "lock; btcl %[nr], %[addr]\n\t"
+    asm volatile ( "lock btcl %[nr], %[addr]\n\t"
                    ASM_FLAG_OUT(, "sbbl %[old], %[old]\n\t")
                    : [old] ASM_FLAG_OUT("=@ccc", "=r") (oldbit),
                      [addr] "+m" (ADDR) : [nr] "Ir" (nr) : "memory" );

diff --git a/xen/arch/x86/include/asm/spinlock.h b/xen/arch/x86/include/asm/spinlock.h
index 56f60957522a627a90e08eab747f5c9a4293f793..834e8c580ebd1112b26dff5cf3dc05f2e42b1fd8 100644 (file)
--- a/xen/arch/x86/include/asm/spinlock.h
+++ b/xen/arch/x86/include/asm/spinlock.h
@@ -3,7 +3,7 @@
 
 #define _raw_read_unlock(l) \
     BUILD_BUG_ON(sizeof((l)->lock) != 4); /* Clang doesn't support %z in asm. */ \
-    asm volatile ( "lock; decl %0" : "+m" ((l)->lock) :: "memory" )
+    asm volatile ( "lock decl %0" : "+m" ((l)->lock) :: "memory" )
 
 /*
  * On x86 the only reordering is of reads with older writes.  In the