@@ -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);
}
}
@@ -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;
Fix a fencepost error in the BUILD_BUG_ON() check. The sentinel must be distinct from any legal cpu id. No resulting change. The compiled binary is identical. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: Jan Beulich <JBeulich@suse.com> CC: Tim Deegan <tim@xen.org> CC: Ian Campbell <Ian.Campbell@citrix.com> CC: Doug Goldstein <cardoe@cardoe.com> Noticed while reviewing Doug's NR_CPUS patch. --- xen/common/spinlock.c | 8 ++++---- xen/include/xen/spinlock.h | 6 ++++-- 2 files changed, 8 insertions(+), 6 deletions(-)