From: Andrew Cooper <andrew.cooper3@citrix.com>
Date: Mon, 18 Jan 2016 13:51:57 +0000 (+0100)
Subject: spinlock: use mnemonics for recursive spinlock sentinel values
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~1952
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=21b151e6bb8f66475bf49d360aceb31172afed22;p=xen.git

spinlock: use mnemonics for recursive spinlock sentinel values

No resulting change.  The compiled binary is identical.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---

diff --git a/xen/common/spinlock.c b/xen/common/spinlock.c
index 7f89694d49..7b0cf6cdba 100644
--- a/xen/common/spinlock.c
+++ b/xen/common/spinlock.c
@@ -246,7 +246,7 @@ int _spin_trylock_recursive(spinlock_t *lock)
     unsigned int cpu = smp_processor_id();
 
     /* Don't allow overflow of recurse_cpu field. */
-    BUILD_BUG_ON(NR_CPUS > 0xfffu);
+    BUILD_BUG_ON(NR_CPUS > SPINLOCK_NO_CPU);
 
     check_lock(&lock->debug);
 
@@ -258,7 +258,7 @@ int _spin_trylock_recursive(spinlock_t *lock)
     }
 
     /* We support only fairly shallow recursion, else the counter overflows. */
-    ASSERT(lock->recurse_cnt < 0xfu);
+    ASSERT(lock->recurse_cnt < SPINLOCK_MAX_RECURSE);
     lock->recurse_cnt++;
 
     return 1;
@@ -275,7 +275,7 @@ void _spin_lock_recursive(spinlock_t *lock)
     }
 
     /* We support only fairly shallow recursion, else the counter overflows. */
-    ASSERT(lock->recurse_cnt < 0xfu);
+    ASSERT(lock->recurse_cnt < SPINLOCK_MAX_RECURSE);
     lock->recurse_cnt++;
 }
 
@@ -283,7 +283,7 @@ void _spin_unlock_recursive(spinlock_t *lock)
 {
     if ( likely(--lock->recurse_cnt == 0) )
     {
-        lock->recurse_cpu = 0xfffu;
+        lock->recurse_cpu = SPINLOCK_NO_CPU;
         spin_unlock(lock);
     }
 }
diff --git a/xen/include/xen/spinlock.h b/xen/include/xen/spinlock.h
index fb0438e542..9555c53487 100644
--- a/xen/include/xen/spinlock.h
+++ b/xen/include/xen/spinlock.h
@@ -80,7 +80,7 @@ struct lock_profile_qhead {
     static struct lock_profile *__lock_profile_##name                         \
     __used_section(".lockprofile.data") =                                     \
     &__lock_profile_data_##name
-#define _SPIN_LOCK_UNLOCKED(x) { { 0 }, 0xfffu, 0, _LOCK_DEBUG, x }
+#define _SPIN_LOCK_UNLOCKED(x) { { 0 }, SPINLOCK_NO_CPU, 0, _LOCK_DEBUG, x }
 #define SPIN_LOCK_UNLOCKED _SPIN_LOCK_UNLOCKED(NULL)
 #define DEFINE_SPINLOCK(l)                                                    \
     spinlock_t l = _SPIN_LOCK_UNLOCKED(NULL);                                 \
@@ -116,7 +116,7 @@ extern void spinlock_profile_reset(unsigned char key);
 
 struct lock_profile_qhead { };
 
-#define SPIN_LOCK_UNLOCKED { { 0 }, 0xfffu, 0, _LOCK_DEBUG }
+#define SPIN_LOCK_UNLOCKED { { 0 }, SPINLOCK_NO_CPU, 0, _LOCK_DEBUG }
 #define DEFINE_SPINLOCK(l) spinlock_t l = SPIN_LOCK_UNLOCKED
 
 #define spin_lock_init_prof(s, l) spin_lock_init(&((s)->l))
@@ -138,7 +138,9 @@ typedef union {
 typedef struct spinlock {
     spinlock_tickets_t tickets;
     u16 recurse_cpu:12;
+#define SPINLOCK_NO_CPU 0xfffu
     u16 recurse_cnt:4;
+#define SPINLOCK_MAX_RECURSE 0xfu
     struct lock_debug debug;
 #ifdef LOCK_PROFILE
     struct lock_profile *profile;