From: Keir Fraser <keir.fraser@citrix.com>
Date: Mon, 20 Oct 2008 16:17:55 +0000 (+0100)
Subject: x86, spinlock: Get rid of .text.lock out-of-line section.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14066^2~15
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=c604d2c2e0cd96e9f64b05217397bb817cdaeb77;p=xen.git

x86, spinlock: Get rid of .text.lock out-of-line section.

We don't care about code bloat now that spinlock operations are not
inlined into callers. This will make backtraces easier to read.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
---

diff --git a/xen/arch/x86/x86_32/xen.lds.S b/xen/arch/x86/x86_32/xen.lds.S
index 2c3d21fced..99fffca441 100644
--- a/xen/arch/x86/x86_32/xen.lds.S
+++ b/xen/arch/x86/x86_32/xen.lds.S
@@ -26,7 +26,6 @@ SECTIONS
 	*(.fixup)
 	*(.gnu.warning)
 	} :text =0x9090
-  .text.lock : { *(.text.lock) } :text	/* out-of-line lock text */
 
   _etext = .;			/* End of text section */
 
diff --git a/xen/arch/x86/x86_64/xen.lds.S b/xen/arch/x86/x86_64/xen.lds.S
index 55559f4678..4f840107ce 100644
--- a/xen/arch/x86/x86_64/xen.lds.S
+++ b/xen/arch/x86/x86_64/xen.lds.S
@@ -24,7 +24,6 @@ SECTIONS
 	*(.fixup)
 	*(.gnu.warning)
 	} :text = 0x9090
-  .text.lock : { *(.text.lock) } :text	/* out-of-line lock text */
 
   _etext = .;			/* End of text section */
 
diff --git a/xen/include/asm-x86/rwlock.h b/xen/include/asm-x86/rwlock.h
index e8c8846cb5..e4474d4a25 100644
--- a/xen/include/asm-x86/rwlock.h
+++ b/xen/include/asm-x86/rwlock.h
@@ -22,25 +22,19 @@
 
 #define __build_read_lock_ptr(rw, helper)   \
 	asm volatile(LOCK "subl $1,(%0)\n\t" \
-		     "js 2f\n" \
+		     "jns 1f\n\t" \
+		     "call " helper "\n\t" \
 		     "1:\n" \
-		     ".section .text.lock,\"ax\"\n" \
-		     "2:\tcall " helper "\n\t" \
-		     "jmp 1b\n" \
-		     ".previous" \
 		     ::"a" (rw) : "memory")
 
 #define __build_read_lock_const(rw, helper)   \
 	asm volatile(LOCK "subl $1,%0\n\t" \
-		     "js 2f\n" \
-		     "1:\n" \
-		     ".section .text.lock,\"ax\"\n" \
-		     "2:\tpush %%"__OP"ax\n\t" \
+		     "jns 1f\n\t" \
+		     "push %%"__OP"ax\n\t" \
 		     "lea %0,%%"__OP"ax\n\t" \
 		     "call " helper "\n\t" \
 		     "pop %%"__OP"ax\n\t" \
-		     "jmp 1b\n" \
-		     ".previous" \
+		     "1:\n" \
 		     :"=m" (*(volatile int *)rw) : : "memory")
 
 #define __build_read_lock(rw, helper)	do { \
@@ -52,25 +46,19 @@
 
 #define __build_write_lock_ptr(rw, helper) \
 	asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
-		     "jnz 2f\n" \
+		     "jz 1f\n\t" \
+		     "call " helper "\n\t" \
 		     "1:\n" \
-		     ".section .text.lock,\"ax\"\n" \
-		     "2:\tcall " helper "\n\t" \
-		     "jmp 1b\n" \
-		     ".previous" \
 		     ::"a" (rw) : "memory")
 
 #define __build_write_lock_const(rw, helper) \
 	asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
-		     "jnz 2f\n" \
-		     "1:\n" \
-		     ".section .text.lock,\"ax\"\n" \
-		     "2:\tpush %%"__OP"ax\n\t" \
+		     "jz 1f\n\t" \
+		     "push %%"__OP"ax\n\t" \
 		     "lea %0,%%"__OP"ax\n\t" \
 		     "call " helper "\n\t" \
 		     "pop %%"__OP"ax\n\t" \
-		     "jmp 1b\n" \
-		     ".previous" \
+		     "1:\n" \
 		     :"=m" (*(volatile int *)rw) : : "memory")
 
 #define __build_write_lock(rw, helper)	do { \
diff --git a/xen/include/asm-x86/spinlock.h b/xen/include/asm-x86/spinlock.h
index 7dc1da0bd8..f5503a2820 100644
--- a/xen/include/asm-x86/spinlock.h
+++ b/xen/include/asm-x86/spinlock.h
@@ -18,14 +18,13 @@ typedef struct {
 static inline void _raw_spin_lock(raw_spinlock_t *lock)
 {
     asm volatile (
-        "1:  lock; decb %0         \n"
-        "    js 2f                 \n"
-        ".section .text.lock,\"ax\"\n"
+        "1:  lock; decw %0         \n"
+        "    jns 3f                \n"
         "2:  rep; nop              \n"
-        "    cmpb $0,%0            \n"
+        "    cmpw $0,%0            \n"
         "    jle 2b                \n"
         "    jmp 1b                \n"
-        ".previous"
+        "3:"
         : "=m" (lock->lock) : : "memory" );
 }
 
@@ -33,16 +32,16 @@ static inline void _raw_spin_unlock(raw_spinlock_t *lock)
 {
     ASSERT(_raw_spin_is_locked(lock));
     asm volatile (
-        "movb $1,%0" 
+        "movw $1,%0" 
         : "=m" (lock->lock) : : "memory" );
 }
 
 static inline int _raw_spin_trylock(raw_spinlock_t *lock)
 {
-    char oldval;
+    s16 oldval;
     asm volatile (
-        "xchgb %b0,%1"
-        :"=q" (oldval), "=m" (lock->lock)
+        "xchgw %w0,%1"
+        :"=r" (oldval), "=m" (lock->lock)
         :"0" (0) : "memory" );
     return (oldval > 0);
 }